| 1. |
Budi Kristiawan, Ahmad Imam Rifa'i, Koji Enoki, Agung Tri Wijayanta, Takahiko Miyazaki, Enhancing the thermal performance of TiO2/water nanofluids flowing in a helical microfin tube, POWDER TECHNOLOGY, 10.1016/j.powtec.2020.08.020, 376, 254-262, 2020.10, A hybrid method with a microfin tube and TiO2/water nanofluid with various nanoparticles concentration has been investigated experimentally. The objectives of this work arc to characterize thermohydraulic including friction factor and thermal performance, and to develop correlation based on the experimental result. In general, adding nanopartides to the base fluid causes increased thermal performance. Pressure drop inside the microfin tube at TiO2/water concentrations of 0.05, 0.15, and 0.30 vol% were respectively 73%, 77%, and 80% higher than that in the smooth tube. Furthermore, the pressure drop increased with an increment in Re number. In this work, the developed correlation was proposed to predict practically Nu number. The present findings contribute to our understanding of how to enhance heat transfer using helical microfins inside tubes and nanofluids. (C) 2020 Elsevier B.V. All rights reserved.. |
| 2. |
Uthpara Perera, Kyaw Thu, Takahiko Miyazaki, Naoya Sakoda, Yukihiro Higashi, Saturation pressure measurements of the new refrigerant HFO1132(E), Proceedings of 2nd Conference on HFOs and Low GWP blends, 10.18462/iir.HFO.2021.1023, 12-19, 2021.06. |
| 3. |
Agung Tri Wijayanta, Indri Yaningsih, Wibawa Endra Juwana, Muhammad Aziz, Takahiko Miyazaki, Effect of wing-pitch ratio of double-sided delta-wing tape insert on the improvement of convective heat transfer, International Journal of Thermal Sciences, 10.1016/j.ijthermalsci.2020.106261, 151, 2020.05, After publishing an article in which the impact of wing-width ratio of double-sided delta-wing tape (T-W) inserts on thermal-hydraulic performance [Wijayanta et al., Appl. Therm. Eng. 145 (2018) 27–37] were investigated, we have extended our work to modified enhanced heat transfer area design for wing-pitch ratio (P/W) acting on the geometric features of delta-wing tape inserts. There are a limited number of studies in this area regarding the wing-pitch ratio. In the current study, T-W inserts with P/W of 1.18, 1.47, and 1.65 were manufactured and evaluated to improve single-phase convective heat transfer, under the conditions of a Reynolds number between 5,300 and 14,500, with water used as the working fluid. T-W inserts with a P/W of 1.18 offer the highest average Nusselt number, with an increase of approximately 177% compared to a plain tube. However, the friction factor is 11.6 times greater compared to a plain tube, showing that the friction loss is more significant with T-W inserts. In addition, T-W inserts with a P/W of 1.18 produce the greatest thermal performance factor of 1.15. Generally, Nusselt number, friction factor, and thermal performance factor of the heat exchanger increase following the decrease of P/W of the T-W inserts. In this study, the empirical correlations have been modeled using the obtained experimental data.. |
| 4. |
Kohei Matsui, Kyaw Thu, Takahiko Miyazaki, A hybrid power cycle using an inverted Brayton cycle with an indirect evaporative device for waste-heat recovery, Applied Thermal Engineering, 10.1016/j.applthermaleng.2020.115029, 170, 2020.04, The inverted Brayton cycle can be applied to exploit the exergy content of the waste heat. The cycle can be operational at low heat source temperatures, and it is particularly suitable for recovering the low-temperature waste heat. Being low temperature-driven, the thermal efficiency of such an inverted Brayton cycle is considerably low. In this study, an attempt has been made to improve the performance of the cycle by hybridizing with an indirect evaporative cooling (IEC) device. A counter-flow type indirect evaporative cooler is introduced to the inverted Brayton cycle to condition the working fluid prior to the compressor inlet. Detailed numerical models for both cycles were developed and validated with the experimental data of Riangvilaikul and Kumar for a counter flow IEC. The performance of the present configuration is compared with various methods of cooling the working fluid such as the conventional air cooling and a recuperator. The proposed cycle exhibits a significant improvement in terms of the specific work output (45%) for all turbine inlet temperatures regardless of the inlet air conditions, while a higher thermal efficiency can be realized for low-temperature heat source below 85 °C.. |
| 5. |
Faizan Shabir, Muhammad Sultan, Takahiko Miyazaki, Bidyut B. Saha, Ahmed Askalany, Imran Ali, Yuguang Zhou, Riaz Ahmad, Redmond R. Shamshiri, Recent updates on the adsorption capacities of adsorbent-adsorbate pairs for heat transformation applications, Renewable and Sustainable Energy Reviews, 10.1016/j.rser.2019.109630, 119, 2020.03, Adsorption cooling is getting huge attention from last few years due to environment-friendly and thermally-driven technology. Many systems designs based on various adsorbent-adsorbate pairs are investigated worldwide to develop a cost-effective and high-performance system. Until now, performance of the systems is lower as compared to conventional compressor-based systems. Performance of the adsorption systems mainly depends on adsorption equilibrium, adsorption kinetics, isosteric heat of adsorption, and thermo-physical/chemical properties of assorted adsorbent-refrigerant pairs. Thereby, the present study aims to review and compare the physical properties (surface area, pore volume/size etc.) of adsorbents and adsorption equilibrium (adsorption isotherm) by various types of adsorbent-adsorbate pairs available in the literature. Amount of adsorbate adsorbed per unit mass of adsorbent has been critically reviewed and compared accordingly. Highest adsorption uptake was attributed in case of R-32 adsorption onto phenol resin-based activated carbon i.e. 2.23 kg/kg (excess adsorption) and 2.34 kg/kg (absolute adsorption) at 30 °C and 1670 kPa. Activated carbon of type Maxsorb-III being highly microporous possesses high surface area and shows good adsorption uptakes for most of the adsorbates including ethanol, methanol R-134a, CO2, R-507A and n-butane. In addition, fundamentals, principle and features of adsorption cooling systems are discussed. Adsorption equilibrium models used to express the adsorption mechanics of adsorbent-adsorbate pairs are explored, and the models’ parameters are collectively listed and discussed. The review is useful to prioritize available adsorbent-adsorbate pairs for adsorption based heat transformation applications. The study is useful for researchers working for the development of adsorbent materials for various applications and conditions.. |
| 6. |
Indri Yaningsih, Agung Tri Wijayanta, Kyaw Thu, Takahiko Miyazaki, Influence of phase change phenomena on the performance of a desiccant dehumidification system, Applied Sciences (Switzerland), 10.3390/app10030868, 10, 3, 2020.02, Demands of standalone dehumidification systems have been increasing in order to realize energy savings in air-conditioning processes. In a desiccant dehumidification system, the water vapor from the moist air undergoes a phase change phenomenon, this being from vapor to adsorbed phase, a process analogous to latent heat exchange. The energy exchange involved in such a process is often significant-up to 80% of the total energy exchange. In this study, the influence of the phase change phenomena involved in a desiccant dehumidification system was evaluated experimentally, along with the performance investigation under low desorption air temperatures of 308, 318, 328, 338, and 345 K. The system was driven by a constant adsorption temperature of 293 K. The dehumidification ability, latent heat ratio, and latent effectiveness were employed as key performance indexes. The results showed that with the increased desorption temperature, the latent heat ratio decreased, whereas the dehumidification ability and latent effectiveness increased. The highest latent heat ratio was found to be 0.61 at the desorption temperature of 308 K, whereas the highest latent effectiveness was obtained at the desorption temperature of 345 K. A suitable temperature for the effective and efficient dehumidification was observed to be 318 K for the current system.. |
| 7. |
František Mikšík, Takahiko Miyazaki, Miki Inada, Detailed investigation on properties of novel commercial mesoporous silica materials, Microporous and Mesoporous Materials, 10.1016/j.micromeso.2019.109644, 289, 2019.11, A detailed investigation on the main characteristics was conducted on a novel and unique group of industrially produced mesoporous silica material. Six materials from a TMPS group were selected in the respect to their pore size ranging from 1.8 nm up to 4.2 nm. Four of the selected samples were also made with silica doping making them potentially attractive for water adsorption applications with the advantage of the pore-tuning possibilities for specific use. The surface area, pore volume and pore size distribution of these materials were established by standard nitrogen adsorption at T = 77.4 K showing typical values of mesoporous silica materials such as high surface area in the range from 600 to 750 m2g−1 and pore volumes reaching 0.38 cm3g−1 in the case of the smallest TMPS-1.5A and 0.98 cm3g−1 in the case of the largest TMPS-4R. The wall thickness was found out regular around 1.5 ~ 2 nm with lower values attributed to bigger pore sized samples promising good structural integrity. Specific heat showed regular values through all the samples at ~ 0.85 J g−1K−1. Additional information on the structural characteristics and the effect on the amount of silanol group presence and the difference on regular and aluminium-doped samples were studied by means of 29Si DD/MAS NMR. Additionally, elemental analysis by EDS was conducted as well. All the characteristics of the TMPS materials were compared to the standard mesoporous silica materials SBA-15 and MCM-41.. |
| 8. |
Muhammad Hamid Mahmood, Muhammad Sultan, Takahiko Miyazaki, Study on water-vapor adsorption onto polymer and carbon based adsorbents for air-conditioning applications, Evergreen, 6, 3, 215-224, 2019.09, Carbon-based materials have shown huge potential in various adsorption based applications e.g. water and wastewater treatment. In addition, these are successfully utilized for various (methanol-, ethanol-, and ammonia-based) closed-cycle adsorption heat pump systems. Significance of polymers is also well-known in drug/medical industry, and therefore extensively studied for various aspects of adsorption. The study comprises two kinds of polymer and carbon- based materials for potential air-conditioning applications. Water vapor adsorption comparison has been made among polymer, carbon-based and conventional hydrophilic adsorbent i.e. silica-gel. The size of desiccant unit in desiccant air-conditioning (DAC) system has been determined and compared accordingly. Results showed that polymer sorbent (PS-II) can reduce the desiccant unit size (in the DAC system) by 2-3 times as compare to conventional silica-gel under particular conditions while utilizing it intelligently.. |
| 9. |
Budi Kristiawan, Agung Tri Wijayanta, Koji Enoki, Takahiko Miyazaki, Muhammad Aziz, Heat transfer enhancement of TiO2/water nanofluids flowing inside a square minichannel with a microfin structure A numerical investigation, Energies, 10.3390/en12163041, 12, 16, 2019.08, A combination of two passive heat transfer enhancement techniques using a microfin structure and nanofluids was investigated numerically. TiO2/water nanofluids flowing inside a square minichannel with a microfin structure (SMM) were observed as a practical application. Increased heat transfer performance was investigated by observing the Nusselt number, friction factor, and performance evaluation criterion (PEC). Velocity and temperature profiles were also demonstrated at a laminar developing flow regime. The SMM used in this work had six microfins (N = 6) and TiO2/water nanofluids with various nanoparticle concentrations of 0.005, 0.01, and 0.1 vol.%. By combining nanofluids as working fluids and SMM as a passive heat transfer enhancement, the maximum PEC value of 1.2 was achieved at Re = 380 with a volume fraction of 0.01 vol.%. It is obvious that compared to water flowing inside the square minichannel microfin, the heat transfer can be increased by using only a nanofluid with a volume fraction of 0.01%. The combination of a microfin and nanofluids as working fluids is strongly recommended due to its excellent performance in terms of heat transfer and economic considerations.. |
| 10. |
Frantisek Miksik, Takahiko Miyazaki, Material selection and properties for adsorption heat storage perspectivity of TMPS series mesoporous silica nano-materials, Adsorption, 10.1007/s10450-019-00107-4, 25, 6, 1137-1145, 2019.08, Six samples from the TMPS family of mesoporous silica nano-materials from Taiyo Kagaku Co., Ltd. were studied for their potential as a medium for the adsorption thermal energy storage. Selected specimens are distinguished by their pore size from 1.9 to 4.1 nm and aluminium doping. As the adsorbate for the adsorption pair was selected water with the most advantageous properties of high latent heat and safe chemical properties. The tested materials doped with aluminium show high affinity towards the selected adsorbate and high uptakes. The theoretical storage energy density of the materials spans from 700 to 1700 kJ kg−1 based on the adsorption heat. The storage capacity depends mostly on the pore volume and partially on the pore size. The theoretical estimation shows the temperature gain of the adsorption potential as high as ΔT=23∘C for the material TMPS-1.5A with the smallest pore diameter and aluminium doping and as low as ΔT=6∘C for the TMPS-4R with the biggest pore diameter and without aluminium doping.. |
| 11. |
Takahiko Miyazaki, Special issue on sciences in heat pump and refrigeration, Applied Sciences (Switzerland), 10.3390/app9112385, 9, 11, 2019.06. |
| 12. |
Shazia Hanif, Muhammad Sultan, Takahiko Miyazaki, Effect of relative humidity on thermal conductivity of zeolite-based adsorbents Theory and experiments, Applied Thermal Engineering, 10.1016/j.applthermaleng.2018.12.144, 150, 11-18, 2019.03, Effective thermal conductivity (ETC) of the adsorbent is an important parameter which influences the performance of the adsorption heat pump and adsorption cooling systems. Most of the adsorbents are porous in nature and therefore adsorption uptake is affected due to different operating conditions i.e. temperature and relative humidity (RH) that result in different ETC. Effect of temperature on ETC is somehow well-known in the literature, however, studies on RH effect are limited. Therefore, present study experimentally investigates the RH effect on the thermal conductivity of the commercially available zeolite-based adsorbents which are traded as: AQSOA-Z02 (zeolite-1) and AQSOA-Z05 (zeolite-2). The study is useful for the researcher who are working in the field of adsorption cooling, air-conditioning and desalination. In this regard, an experimental setup was developed by which the ETC was measured at different levels of RH. According to the results, the ETC of oven dried zeolite-1 and zeolite-2 was 0.060 W m−1 K−1 and 0.066 W m−1 K−1, respectively. With the increase in RH, the value of ETC increases up to 0.090 W m−1 K−1 for zeolite-1 and 0.089 W m−1 K−1 for zeolite-2. Moreover, an empirical relation is proposed which can estimate ETC at different levels of RH for both adsorbents.. |
| 13. |
Muhammad H. Mahmood, Muhammad Sultan, Takahiko Miyazaki, Experimental evaluation of desiccant dehumidification and air-conditioning system for energy-efficient storage of dried fruits, Building Services Engineering Research and Technology, 10.1177/0143624419893660, 2019.01, The ideal storage zones of dried fruits in comparison with dried foods and feeds are established on the psychrometric chart. The study investigates the combined effect of the desiccant dehumidification and Maisotsenko-Cycle evaporative cooling for the dried fruits storage. Two configurations of desiccant air-conditioning systems (S-I and S-II) are proposed, and their performance is evaluated under the ambient conditions of Fukuoka, Japan. It is established on the basis of parametric and thermodynamic analysis of both the system configurations (S-I and S-II) that S-II could yield better system performance. The psychrometric evaluation of S-II revealed that it can provide the optimal conditions for the storage of dried fruits at low regeneration temperature. However, modification in the proposed system configuration (S-II) is suggested for the storage of dried foods and feeds. Practical application: Conventional dehumidification and air-conditioning options are either expensive or inefficient for dried fruit storage buildings. The study provides a way forward of using thermally driven desiccant systems which are energy-efficient and environment-friendly. Worldwide, the building industries are actively involved in the development of such systems but their application for dried fruit storage buildings are not explored in detail. Therefore, the study provides thermodynamic details of dried fruits storage in relation with experimental evaluation of desiccant and evaporative cooling systems. Provision of such systems to the storage buildings will provide distinct control of humidity and temperature for optimal storage.. |
| 14. |
Shazia Hanif, Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, Investigation of energy-efficient solid desiccant system for the drying of wheat grains, International Journal of Agricultural and Biological Engineering, 10.25165/j.ijabe.20191201.3854, 12, 1, 221-228, 2019.01, The study investigates the applicability of solid desiccant system for drying of freshly harvested wheat grains in order to reduce the moisture to an optimum level. Fast and low-temperature drying systems are required by today’s drying industries in order to provide economical and safe drying. Therefore, comparison of desiccant drying has been made with the conventional method in terms of drying kinetics, allowable time for safe storage, the total time for drying cycle, and overall energy consumption. It has been found that the air conditions of proposed desiccant drying system provides a high drying rate and longer allowable storage time for the safe drying. As the desiccants possess water adsorbing ability by means of vapor pressure deficit, therefore, the desiccant system successfully provides low-temperature drying which ensures the quality of wheat grains. Overall energy consumption is estimated for both conventional hot air drying and desiccant drying system. It has been found that the desiccant system requires less energy as drying is accomplished at minimum level of air flow and within allowable storage time. In addition, the overall performance index of the desiccant system is higher at all temperatures. The study is useful for developing a low-cost and sustainable drying technology for various agricultural products.. |
| 15. |
Muhammad Hamid Mahmood, Muhammad Sultan, Takahiko Miyazaki, Significance of Temperature and Humidity Control for Agricultural Products Storage Overview of Conventional and Advanced Options, International Journal of Food Engineering, 10.1515/ijfe-2019-0063, 2019.01, The agricultural products are perishable in nature and possesses short shelf/storage life under ambient conditions. The temperature and humidity control systems are required to enhance to storage life of the products with optimum quality, quantity and nutritive attributes. In this regard, the significance of air-conditioning in storage application is highlighted along with the conventional storage options. The implications of compressor-based refrigeration and air-conditioning systems regarding low-cost and energy efficient air-conditioning systems are discussed in detailed. It is concluded that thermally driven air-conditioning systems can be used on top priority for the short-term storage of fresh agricultural products. Moreover, the long-term storage of products at freezing temperature can be made through hybrid systems instead of standalone conventional compressor based vapor compression refrigeration and/or air-conditioning systems. Finally, the air-conditioning systems are proposed for the optimum storage of different categorize of the food products.. |
| 16. |
Muhammad H. Mahmood, Muhammad Sultan, Takahiko Miyazaki, Solid desiccant dehumidification-based air-conditioning system for agricultural storage application Theory and experiments, Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 10.1177/0957650919869503, 2019.01, This study experimentally investigates desiccant dehumidification and indirect evaporative cooling for agricultural products' storage. Thermodynamic advantages of the proposed system are highlighted and compared to vapor compression systems. Significance of proposed system is discussed in relation to agricultural storage application. Factors affecting the postharvest quality of products are discussed, and consequently, the psychrometric zones are established for optimum storage. Hydrophilic polymeric sorbent-based desiccant units are used for the experimental investigation. An open-cycle experimental apparatus is setup by which desiccant dehumidification and regeneration processes are analyzed at various conditions. Thereby, a novel correlation is developed by which desiccant dehumidification process can be simulated precisely. The correlation is successfully validated against the experimental data of various conditions. Desiccant air-conditioning cycle is analyzed for two cases (i.e. case-A: dry-bulb temperature = 31 ℃, humidity-ratio = 6 g/kg-DA; and case-B: dry-bulb temperature = 13 ℃, humidity-ratio = 6 g/kg-DA) to investigate the proposed system's applicability for agricultural storage. The results show that the thermal coefficient of performance is highly influenced by ambient air conditions and decreases with the increase in regeneration temperature. The thermal coefficient of performance for case-A is higher as compared to case-B, and for both cases, it increases with the increase in wet-bulb effectiveness of the evaporative cooling unit.. |
| 17. |
Muhammad Sultan, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Hyun Sig Kil, Koji Nakabayashi, Jin Miyawaki, Seong-Ho Yoon, Adsorption of Difluoromethane (HFC-32) onto phenol resin based adsorbent Theory and experiments, International Journal of Heat and Mass Transfer, 10.1016/j.ijheatmasstransfer.2018.07.097, 127, 348-356, 2018.12, Adsorption and desorption of difluoromethane (HFC-32) onto newly developed phenol resin based adsorbent (SAC-2) have been measured experimentally for the isotherm temperatures ranging from 30 °C to 130 °C and pressure up to 3 MPa. A magnetic suspension balance based adsorption measurement unit is used to measure adsorption uptake gravimetrically. The presented SAC-2/HFC-32 pair has adsorption uptake as high as 2.23 kg
ref
/kg
ads
(excess adsorption) and 2.34 kg
ref
/kg
ads
(absolute adsorption) at 30 °C and 1.67 MPa. To the best of our knowledge, it is the highest HFC-32 adsorption capacity onto any adsorbent available in the literature. The experimental data of adsorption/desorption isotherms show that there is no hysteresis for the studied pair. The data have been fitted with Tóth; Dubinin–Astakhov (D–A); and Guggenheim, Anderson, De-Boer (GAB) adsorption isotherm models. The parameters of adsorption isotherm models are optimized by nonlinear optimization technique. The D–A model fits the experimental data precisely as compared to other models. In addition, numerical values of isosteric heat of adsorption have also been extracted by means of Clausius–Clapeyron equation using adsorption isotherm models.. |
| 18. |
Agung Tri Wijayanta, Indri Yaningsih, Muhammad Aziz, Takahiko Miyazaki, Shigeru Koyama, Double-sided delta-wing tape inserts to enhance convective heat transfer and fluid flow characteristics of a double-pipe heat exchanger, Applied Thermal Engineering, 10.1016/j.applthermaleng.2018.09.009, 145, 27-37, 2018.12, One of the challenges in the development of heat exchangers is to minimize their energy consumption. This can be achieved by enhancing the heat transfer rate, which will boost the thermal performance of heat exchangers. Delta-wing vortex generators fitted in a double-pipe heat exchanger will generate vortices with more intermixing of the flowing fluid, and provide the improvement of convective heat transfer of the internal flow. In this study, double-sided delta-wing (T-W) tape inserts were designed to enhance convective heat transfer of a double-pipe heat exchanger. The effects of the wing-width ratio (0.31, 0.47, and 0.63) on the heat transfer and fluid flow characteristics of the heat exchanger were investigated by experiments where water was used as the working fluid and the Reynolds number was varied from 5300 to 14,500. The results were compared with those obtained for a plain tube and tube with longitudinal strip (L-S) insert. The T-W tape insert (wing-width ratio: 0.63) results in the highest average Nusselt number, where the average Nusselt number is higher by 177% relative to that for the plain tube. Despite the significant heat transfer enhancement, the friction factor is 11.6 times higher relative to that for the plain tube, indicating that friction loss is more pronounced due to the presence of T-Ws. The T-W tape insert (wing-width ratio: 0.63) also results in the highest thermal performance factor (1.15). The Nusselt number, thermal performance factor, and friction factor of the heat exchanger increases as the wing-width ratio of the T-Ws increases. Based on the experimental data, empirical correlations were developed to predict the Nusselt number and friction factor of the double-pipe heat exchanger with T-W tape inserts.. |
| 19. |
Indri Yaningsih, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Thermal hydraulic characteristics of turbulent single-phase flow in an enhanced tube using louvered strip insert with various slant angles, International Journal of Thermal Sciences, 10.1016/j.ijthermalsci.2018.08.025, 134, 355-362, 2018.12, Effect of slant angle (α) of louvered strip insert on single-phase forced convection heat transfer and friction factor of internal flow was investigated experimentally. The parameter of slant angles (α) 15° 20° and 25° was examined at the Reynolds number (Re) of 5300–17,500. The plain tube was also performed for comparison. The results show that the louvered strip insert provided the increases in heat transfer and friction factor up to 77.02% and 3.35 times above the plain tube. The results also indicate that heat transfer and friction factor increased with increasing slant angle. The highest slant angle yielded the highest thermal performance factor in the value of 1.12. Empirical correlations were also developed for Nusselt number and friction factor based on experimental data.. |
| 20. |
František Mikšík, Jan Skolil, Josef Kotlík, Čáslavský Josef, Takahiko Miyazaki, Marie Kačírková, Helena Pučková, Viscosities, Densities, and Refractive Indices of Aqueous Propane-1,3-diol, Journal of Chemical and Engineering Data, 10.1021/acs.jced.8b00403, 63, 12, 4350-4367, 2018.12, A detailed investigation into the viscosity, density, and refractive index of a binary mixture of propane-1,3-diol/water was performed for the whole range of mass fractions of propane-1,3-diol. The viscosity and density were measured over a wide range of temperatures from T = 253.15 K to T = 353.15 K where possible, or to the nearest safe point before freezing. The refractive indices were measured for the same dilutions as in the case of the viscosity and density over a reduced temperature range of T = (278.15 to 318.15) K. A mathematical analysis via excess properties was conducted and fitted to the Redlich-Kister equation. Furthermore, a prediction of density data is provided by a polynomial and DIPPR exponential model. The viscosity data are fitted to Grunberg-Nissan, Lederer, McAllister, and Heric models and a new combined model with variable temperature and molar and mass fractions based on these models is presented. Data comparison of the propane-1,3-diol/water binary mixture is performed on propan-1,2-diol/water mixture as the physically closest binary system and application alternative fluid.. |
| 21. |
Indri Yaningsih, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Analysis of heat and mass transfer characteristics of desiccant dehumidifier system with honeycomb configuration, Applied Thermal Engineering, 10.1016/j.applthermaleng.2018.08.066, 144, 658-669, 2018.11, Adjusting the heat and moisture of a conditioned space is important to maintain the comfort of the air. Adding or removing heat and moisture depends mainly on the heat and mass transfer characteristics within the system. In this study, the heat and mass transfer characteristics, in the form of the Nusselt number (Nu) and the Sherwood number (Sh), of a honeycomb desiccant dehumidifier (HDDH) were investigated experimentally. The HDDH was driven by using the honeycomb desiccant configuration, which was constructed from a polymer adsorbent material. The adsorption temperature (Tads) was considered as an adjustable parameter using values of 20 °C, 25 °C, and 35 °C. Each adsorption temperature was evaluated under the time intervals for the desorption and adsorption processes (switching time: τ) of 60:60 min, 60:90 min, 60:120 min, and 90:120 min. For the given parameters, the desorption temperature and mass flow rate of the air were kept unchanged at 55 °C and 0.1 kg/s, respectively. The results showed that the Nu and Sh are more evenly responsive to change of adsorption temperature than switching time. Low desorption temperature results in high values of Nu and Sh. However, variation of switching time produces little change in Nu and Sh. Empirical correlations were also developed in this study. The empirical correlations matched the experimental data well.. |
| 22. |
Shinnosuke Maeda, Kyaw Thu, Tomohiro Maruyama, Takahiko Miyazaki, Critical review on the developments and future aspects of adsorption heat pumps for automobile air conditioning, Applied Sciences (Switzerland), 10.3390/app8112061, 8, 11, 2018.10, Emission and heat rejection from automobiles are largely responsible for urban environmental issues. Adsorption systems driven by engine waste heat exhibit huge potential to meet the demand for cabin thermal comfort while improving fuel economy. However, the mechanical vapour compression (MVC) systems are still the undisputed champions in automobile air conditioning. This paper provides a critical review on the development and progress of adsorption heat pumps specifically for automobile air conditioning. In doing so, some of the progress and development in land-based adsorption chillers (heat pump), which are not realistically relevant to automobile adsorption systems, are explicitly excluded. Matching the energy density, durability, and reliability of the MVC systems remain major hurdles. The importance of improving the energy density based on the overall system weight or volume, real-world tests under various driving modes and durability aspects are discussed.. |
| 23. |
Takahiko Miyazaki, Evaporative heat exchangers, Handbook of Thermal Science and Engineering, 10.1007/978-3-319-26695-4_22, 1521-1533, 2018.07, This chapter starts from introduction of water as a refrigerant, and suitability of water refrigerant for evaporative heat exchangers rather than for two phase flow heat exchangers is discussed from a thermodynamic point of view. Then, a theory and analytical studies of evaporative cooling processes are described using psychrometric chart. A new thermodynamic concept of evaporative cooling, which is a breakthrough in cooling technology, is introduced and explained. Lastly, applications of evaporative heat exchangers for air cooling/humidification and for water cooling are presented.. |
| 24. |
Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, Optimization of adsorption isotherm types for desiccant air-conditioning applications, Renewable Energy, 10.1016/j.renene.2018.01.045, 121, 441-450, 2018.06, The present study investigates five kinds of adsorbents for desiccant air-conditioning (DAC) applications. Each adsorbent yield distinctive water vapor adsorption isotherm that can be categorized as type-I, type-II, type-III, type-V, and type-linear on the basis of the International Union of Pure and Applied Chemistry (IUPAC) classification. Ideal DAC cycle is evaluated for the air-conditioning (AC) applications, and steady-state moisture cycled (MCSS) is estimated by means of adsorption isobars. Results showed that the adsorbent enabling type-linear adsorption isotherm gives maximum MCSS for industrial AC processes of matches manufacturing/drying/storage, rubber dipped goods storage and photo studio drying room. However, adsorbent enabling type-V adsorption isotherm is found the optimum adsorbent for tobacco stemming/stripping/softening and optical lenses grinding. For industrial AC process of dipped surgical articles
adsorbents enabling type-II, type-linear, and type-I adsorption isotherms are found the optimum choice at low (<
68 °C), medium (68°C-87 °C), and high (>
87 °C) regeneration temperatures, respectively.. |
| 25. |
Indri Yaningsih, Muhammad Hamid Mahmood, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Experimental study on dehumidification technology using honeycomb desiccant block, Evergreen, 10.5109/1936212, 5, 2, 11-18, 2018.06, The current research highlights the potential of using desiccant dehumidification technology with the merits of low initial energy consumptions. The system consists of desiccant (DSC) block units, dehumidification and regeneration air sources, air flow control valves, and a set of the heat exchanger. Attention was given to the DSC blocks. The blocks were made of hydrophilic polymer with honeycomb shaped. The present study focuses on the heat and mass transfer (HMT) characteristics to enhance the performance of the system. Three different process air temperatures of 20°C, 25°C, and 35°C were investigated under constant regeneration air temperature of 55°C and inlet air velocity of 0.1 kg/s. For each process air temperature, four different switching time ratios were also introduced to examine the HMT balance of the DSC blocks. The results revealed that the dehumidification capacity of the DSC system has high potential as air conditioning devices. The discrepancy of HMT found was less than 8%. Hence, the experimental methods were reliable to conduct the further experiments.. |
| 26. |
Budi Kristiawan, Budi Santoso, Agung Tri Wijayanta, Muhammad Aziz, Takahiko Miyazaki, Heat transfer enhancement of TiO2/water nanofluid at laminar and turbulent flows A numerical approach for evaluating the effect of nanoparticle loadings, Energies, 10.3390/en11061584, 11, 6, 2018.06, Titania-based nanofluid flowing inside a circular tube under the boundary condition of a horizontal uniformly heated wall was investigated numerically for both laminar and turbulent flows. In this work, an innovative numerical method using an Eulerian approach for the two-phase mixture model was used to simulate the flow and convective heat transfer characteristics. The effect of nanoparticle loading and Reynolds number on the flow and heat transfer characteristics was observed. The Reynolds number was 500 and 1200 for laminar flow, while for turbulent flow, the Reynolds number was varied in the range from 4000 to 14,000. A comparison with the established empirical correlations was made. The results clearly showed at the laminar and turbulent flows that the existing nanoparticles provided a considerable enhancement in the convective heat transfer. For laminar flow, the numerical results found that the enhancement in the convective heat transfer coefficient of nanofluids were 4.63, 11.47, and 20.20% for nanoparticle loadings of 0.24, 0.60, and 1.18 vol.%, respectively. On the other hand, for turbulent flow, the corresponding heat transfer increases were 4.04, 10.33, and 21.87%.. |
| 27. |
Khanam Marzia, Muhammad Faisal Hasan, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Key factors of solar energy progress in Bangladesh until 2017, Evergreen, 10.5109/1936220, 5, 2, 78-85, 2018.06, Renewable energy (RE) is the potential solution to the current world’s problems pertaining to the energy crisis and environmental concerns. Like other countries Bangladesh, which is currently starving for energy, has given more importance to RE especially solar energy to mitigate the energy-related problems. According to RE policy of Bangladesh, the targeted RE share was 5% to be achieved by 2015 (500 MW). At the beginning of 2018, the country was able to install ~506 MW from RE sources (3.10%), in which significant portion comes from solar energy. The factors that contributed mainly to achieve the target are government policies and initiatives, international influence, solar panel price reduction, private sector participation, public awareness. In this study, the influences of these factors have been discussed. Besides, the technologies implemented for the fulfillment of RE share target has been analyzed.. |
| 28. |
Marzia Khanam, Skander Jribi, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Numerical investigation of small-scale adsorption cooling system performance employing activated carbon-ethanol pair, Energies, 10.3390/en11061499, 11, 6, 2018.06, Adsorber heat exchanger design has great importance in increasing the performance of the adsorption-based cooling system. In this study, a transient two-dimensional axisymmetric Computational Fluid Dynamics (CFD) model has been developed for the performance investigation of finned tube type adsorber using activated carbon and ethanol as the working pair. The operating conditions of the cooling system were 15, 20 and 80 for evaporation, cooling and heating temperatures, respectively. The simulated temperature profiles for different adsorbent thicknesses were validated with those from experimental data measured in our laboratory. Moreover, the error in mass and energy balance were 3% and 7.88%, respectively. Besides, the performance investigation has been performed for cycle time ranging from 600 s to 1400 s. The optimum cycle time was 800 s and the corresponding evaluated specific cooling power (SCP) and coefficient of performance (COP) were found to be 488 W/kg and 0.61, respectively. The developed CFD model will be used for fin height and fin pitch optimization and can be extended to other adsorbent-adsorbate based adsorption cooling system.. |
| 29. |
Muhammad Faisal Hasan, Md. Sayeed Ur Rahim Mahadi, Takahiko Miyazaki, Shigeru Koyama, Kyaw Thu, Exergy analysis of serpentine thermosyphon solar water heater, Applied Sciences (Switzerland), 10.3390/app8030391, 8, 3, 2018.03, The performance of a solar hot water system is assessed for heat pump and domestic heating applications. Thermodynamic analysis on a serpentine-type thermosyphon flat-plate solar heater is conducted using the Second Law of thermodynamics. Exergetic optimization is first performed to determine the parameters for the maximum exergy efficiency using MATLAB optimization toolbox. Geometric parameters (collector surface area, dimensions, and pipe diameter), optical parameters (transmittance absorptance product), ambient temperature, solar irradiation and operating parameters (mass flow rate, fluid temperature, and overall heat transfer (loss) coefficient) are accounted for in the optimization scheme. The exergy efficiency at optimum condition is found to be 3.72%. The results are validated using experimental data and found to be in good agreement. The analysis is further extended to the influence of various operating parameters on the exergetic efficiency. It is observed that optical and thermal exergy losses contribute almost 20%, whereas approximately 77% exergy destruction is contributed by the thermal energy conversion. Exergy destruction due to pressure drop is found negligible. The result of this analysis can be used for designing and optimization of domestic heat pump system and hot water application.. |
| 30. |
Muhammad Sultan, Takahiko Miyazaki, Muhammad H. Mahmood, Zahid M. Khan, Solar assisted evaporative cooling based passive air-conditioning system for agricultural and livestock applications, Journal of Engineering Science and Technology, 13, 3, 693-703, 2018.03, Solar-chimney assisted evaporative cooling based passive-air-conditioning (SCAC) system has been investigated for different climatic cities of Pakistan. Driving force of system is based on solar chimney and electric fan for day and night time operations, respectively. Ideal temperature and humidity zones are formulated for agricultural products’ storage and animals’ thermal comfort. Recent studies have proven the advancement of Maisotsenko Cycle (M-Cycle) in air-conditioning (AC) field; therefore, SCAC system utilizes M-Cycle conception in order to achieve dew-point cooling. On the basis of M-Cycle experimental data available via literature, study provides thermodynamic investigation of SCAC system for various conditions. Two simplified correlations are developed for performance evaluation of M-Cycle unit. Both correlations showed precise agreement with experimental data with R2 > 0.95. The SCAC system could achieve sensible load of AC efficiently for various applications; however, performance index varies according to climatic conditions. The SCAC system’s applicability was found limited in humid areas because of nature of M-Cycle operation. Therefore, it has been concluded that system may not be sustainable as standalone AC, but it can be a convenient solution in order to reduce the AC load. Moreover, it can provide chilled ceiling for various applications with the low-cost operation. It can be efficiently utilized in most of the dry and moderate areas, whereas, the system’s applicability is limited in humid and water scared regions.. |
| 31. |
Shazia Hanif, Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, Steady-state investigation of desiccant drying system for agricultural applications, Evergreen, 5, 1, 33-42, 2018.03, Present study provides the applicability of desiccant drying system (DDS) for the drying of cereals grain at low temperature and lower humidity. The performance of two drying approaches with two desiccant materials i.e. silica gel and lithium chloride (LiCl) have been analyzed by a desiccant dehumidification model available in literature. Two desiccant drying cases discussed are: Case-I, latent load control effect, Case-II both latent and sensible load control effect. Case-I approach seems more effective towards the drying of delicate and temperature sensitive agricultural product like seeds. However, results showed that Case-II gives more economical and energy saving drying solution for the commercial purpose drying. Regarding the appropriate desiccant material used, LiCl is appropriate choice for Case-I and silica gel is appropriate choice for Case-II.. |
| 32. |
Sofia Fitrina, Budi Kristiawan, Eko Surojo, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Influence of minimum quantity lubrication with Al2O3 nanoparticles on cutting parameters in drilling process, 3rd International Conference on Industrial Mechanical, Electrical, and Chemical Engineering, ICIMECE 2017
3rd International Conference on Industrial Mechanical, Electrical, and Chemical Engineering, 10.1063/1.5024115, 1931, 2018.02, Machining is one of the largest and most widely used methods of production segments in industries. In this way, cutting fluids play an important role in minimizing production time, cost, and energy in various machining operations. This paper presents an experimental investigation into minimum quantity lubrication (MQL) with Al2O3 nanoparticles in drilling process of common rail as work material with DPSCM 435H code to analyze its influence on cutting parameters. Al2O3 has been selected for nanoparticles in this study due to its non-toxicity and spherical shapes for enhanced tribological attributes. Experiments were carried out for two different conditions; MQL + nanofluids (250 ml/h) and conventional cutting fluid (15 liters/min). In this work, nanofluid was prepared by adding Al2O3 nanoparticles (13 nm size) into the conventional cutting fluid in the specific proportion of 1.2 vol.%. The experiment results reveal that the performance of Al2O3 nanofluid in term surface roughness is better compared to the conventional cutting fluid, but the result of cutting temperature and chip morphology does not match with the previous experiment because volume fraction of nanofluid is too high. It means the specific proportion of 1.2 vol.% nanofluid is not best volume fraction for getting best cooling properties. This experiment does not focus on variations of volume fraction but on cooling conditions.. |
| 33. |
Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, Zahid M. Khan, Performance evaluation of hydrophilic organic polymer sorbents for desiccant air-conditioning applications, Adsorption Science and Technology, 10.1177/0263617417692338, 36, 1-2, 311-326, 2018.02, The present study provides performance evaluation of two kinds of crosslinked hydrophilic organic polymer sorbents (PS-I and PS-II) for desiccant air-conditioning applications. In this regard, optimum temperature and humidity zones are established for various air-conditioning applications which include (i) humans’ thermal comfort, (ii) animals’ thermal comfort, and (iii) postharvest storage of fruits/vegetables. Honeycomb-like desiccant blocks composed of PS-I/PS-II are assumed for numerical simulation analysis. The numerical simulation model is programmed into MATLAB which utilizes the scientific relationships of adsorption isotherms, adsorption kinetics, isosteric heat of adsorption, and thermophysical properties for each sorbent. A particular desiccant air-conditioning system design is proposed, and numerical simulation has been conducted for the performance evaluation of PS-I and PS-II. According to the results, PS-I enables higher dehumidification than PS-II at low regeneration temperature (50℃) and cycle time of 60:90 min. It is because the PS-I possesses better water vapor sorption kinetics as compared to PS-II. Although the PS-II enabled higher steady-state adsorption amount but it could not influence the overall system performance. On the other hand, the optimum performance by the PS-II is limited to relatively long cycle time and higher regeneration temperature (≥80℃). It has been concluded that the PS-I is relatively better choice for desiccant air-conditioning, and consequently can be considered for various air-conditioning applications. Furthermore, effects of mass flow rate, isosteric heat of adsorption, regeneration temperature, and cycle time on air humidity ratio and air temperature profiles have been discussed in order to highlight the performance variability of desiccant air-conditioning system.. |
| 34. |
Indri Yaningsih, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, V-cut twisted tape insert effect on heat transfer enhancement of single phase turbulent flow heat exchanger, 3rd International Conference on Industrial Mechanical, Electrical, and Chemical Engineering, ICIMECE 2017
3rd International Conference on Industrial Mechanical, Electrical, and Chemical Engineering, 10.1063/1.5024097, 1931, 2018.02, Turbulator is recognized as a method to increase the performance of the heat exchanger. Turbulator in the form of V-cut twisted tape insert could help to increase the performance by enhancing the coefficient of the heat transfer. This paper proposes a new design of V-cut twisted tape insert (VTT) with different width ratio (w/W), which investigated on the heat transfer enhancement, in the form of Nusselt number (Nu) and friction factor (f) characteristics. Three different width ratios (w/W) 0.32; 0.38 and 0.48 are introduced in this experiment. The working fluid is the hot water in the inner tube and cold water in the annulus, the flow direction is counter-flow. The temperature inlet of hot water is kept constant at 60°C while the flow rate is in the range of Reynolds number 5400 - 17,350. The heat exchanger without insertion (plain tube) and typical twisted tape insert (TT) are examined for comparison. Results indicate that the proposed VTT increases the heat transfer, friction factor, and thermal performance of the heat exchanger. Under the similar condition, VTT provides the best performance in comparison with TT and plain tube. Decreasing width ratio (w/W) increases the heat transfer and thermal performance. However, when the heat transfer is increased, the friction factor is also increasing. The results also revealed that the use of the VTT and TT, the increase in the heat transfer and friction factor up to 97% and 3.48 times of the plain tube. The highest thermal performance is 1.4.. |
| 35. |
Sofia Fitrina, Budi Kristiawan, Eko Surojo, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Influence of minimum quantity lubrication with Al2O3 nanoparticles on cutting parameters in drilling process, AIP Conference Proceedings, 10.1063/1.5024115, 1931, 2018.02, Machining is one of the largest and most widely used methods of production segments in industries. In this way, cutting fluids play an important role in minimizing production time, cost, and energy in various machining operations. This paper presents an experimental investigation into minimum quantity lubrication (MQL) with Al2O3 nanoparticles in drilling process of common rail as work material with DPSCM 435H code to analyze its influence on cutting parameters. Al2O3 has been selected for nanoparticles in this study due to its non-toxicity and spherical shapes for enhanced tribological attributes. Experiments were carried out for two different conditions
MQL + nanofluids (250 ml/h) and conventional cutting fluid (15 liters/min). In this work, nanofluid was prepared by adding Al2O3 nanoparticles (13 nm size) into the conventional cutting fluid in the specific proportion of 1.2 vol.%. The experiment results reveal that the performance of Al2O3 nanofluid in term surface roughness is better compared to the conventional cutting fluid, but the result of cutting temperature and chip morphology does not match with the previous experiment because volume fraction of nanofluid is too high. It means the specific proportion of 1.2 vol.% nanofluid is not best volume fraction for getting best cooling properties. This experiment does not focus on variations of volume fraction but on cooling conditions.. |
| 36. |
Indri Yaningsih, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, V-cut twisted tape insert effect on heat transfer enhancement of single phase turbulent flow heat exchanger, AIP Conference Proceedings, 10.1063/1.5024097, 1931, 2018.02, Turbulator is recognized as a method to increase the performance of the heat exchanger. Turbulator in the form of V-cut twisted tape insert could help to increase the performance by enhancing the coefficient of the heat transfer. This paper proposes a new design of V-cut twisted tape insert (VTT) with different width ratio (w/W), which investigated on the heat transfer enhancement, in the form of Nusselt number (Nu) and friction factor (f) characteristics. Three different width ratios (w/W) 0.32
0.38 and 0.48 are introduced in this experiment. The working fluid is the hot water in the inner tube and cold water in the annulus, the flow direction is counter-flow. The temperature inlet of hot water is kept constant at 60°C while the flow rate is in the range of Reynolds number 5400 - 17,350. The heat exchanger without insertion (plain tube) and typical twisted tape insert (TT) are examined for comparison. Results indicate that the proposed VTT increases the heat transfer, friction factor, and thermal performance of the heat exchanger. Under the similar condition, VTT provides the best performance in comparison with TT and plain tube. Decreasing width ratio (w/W) increases the heat transfer and thermal performance. However, when the heat transfer is increased, the friction factor is also increasing. The results also revealed that the use of the VTT and TT, the increase in the heat transfer and friction factor up to 97% and 3.48 times of the plain tube. The highest thermal performance is 1.4.. |
| 37. |
Indri Yaningsih, Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Impact of blockage ratio on thermal performance of delta-winglet vortex generators, Applied Sciences (Switzerland), 10.3390/app8020181, 8, 2, 2018.01, The impact of double-sided delta-winglet tape (DWTs) inserts on convective heat transfer and friction behaviors in a tube was experimentally investigated. Three DWTs with ratios of winglet-height (b) to inner tube diameter (di) called blockage ratio (Rb) of 0.28, 0.35 and 0.42 were tested and their performance was compared to that of a longitudinal strip and plain tube under similar test flow conditions. Experiments were conducted over a wide range of flow rates, 3.35 × 10-5-8.33 × 10-5 m3/s, which correspond to 5500 ≥ Reynolds number (Re) ≥ 14,500 in the 14.3 mm i.d. tube. The results revealed that using DWTs dramatically increased the Nusselt number (Nu) by as much as 364.3% and the friction factor (f) by 15.5 times compared with those of a plain tube. Thermal performance (η) increased with a corresponding increase in Rb. The highest thermal performance (η) obtained was 1.4. Showing a notable improvement on the thermal performance of the system, DWTs are proposed as a favorable insert device.. |
| 38. |
Animesh Pal, Hyun-Sig Kil, Sourav Mitra, Kyaw Thu, Bidyut Baran Saha, Seong-Ho Yoon, Jin Miyawaki, Takahiko Miyazaki, Shigeru Koyama, Ethanol adsorption uptake and kinetics onto waste palm trunk and mangrove based activated carbons, APPLIED THERMAL ENGINEERING, 10.1016/j.applthermaleng.2017.04.099, 122, 389-397, 2017.07, Equilibrium adsorption uptake and kinetics of ethanol onto highly porous activated carbons (ACs) derived from two types of biomass namely waste palm trunk (WPT) and mangrove (M) have been experimentally measured at adsorption temperatures ranging from 30 to 70 degrees C for various evaporation pressures. A magnetic suspension adsorption measurement unit has been used for the experimental measurements. Four well-known adsorption isotherm models have been employed to fit the experimental data whilst two classical adsorption kinetics models i.e. Linear driving force (LDF) model and Fickian diffusion (FD) model are used to predict the experimental kinetics data. Among the four isotherm models Dubinin Astakhov (D-A), and Toth equations agree well with the experimental uptake data for both ACs. The diffusion time constants are calculated at each adsorption temperature for WPT-AC/ethanol and M-AC/ethanol pairs. Moreover, activation energy and pre-exponential constant have been determined from the Arrhenius equation. (C) 2017 Elsevier Ltd. All rights reserved.. |
| 39. |
Skander Jribi, Takahiko Miyazaki, Bidyut Baran Saha, Animesh Pal, Mohamed M. Younes, Shigeru Koyama, Aref Maalej, Equilibrium and kinetics of CO2 adsorption onto activated carbon, INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 10.1016/j.ijheatmasstransfer.2016.12.114, 108, 1941-1946, 2017.05, Knowledge of adsorption characteristics of adsorbent-adsorbate pairs is essential for designing adsorption beds for adsorption cooling and adsorptive gas capturing applications. We investigated the adsorption isotherms and the adsorption kinetics of CO2 onto microporous activated carbon powder of type Maxsorb III. Measurements were performed with gravimetric apparatus for temperatures from 30 to 70 degrees C and pressures up to 7 MPa for adsorption isotherms and up to 4 MPa for adsorption kinetics. The gravimetric adsorption data obtained were consistent with previously measured isotherms with volumetric apparatus. Both absolute and excess adsorption data have been fitted precisely with Toth and Dubinin-Astakhov isotherm equations. The classical linear driving force (LDF) model with a constant mass transfer coefficient failed to correlate the experimental adsorption kinetics data. To overcome this problem, the authors presented a modified LDF equation with a variable mass transfer coefficient which is a function of the equilibrium and instantaneous uptakes. This modified LDF equation led to a better fitting and could be implemented easily in simulation of pressure swing adsorption (PSA), temperature swing adsorption (TSA) and adsorption chiller applications. (C) 2017 Elsevier Ltd. All rights reserved.. |
| 40. |
Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Analytical Model of a Combined Adsorption Cooling and Mechanical Vapor Compression Refrigeration System, Heat Transfer Engineering, 10.1080/01457632.2016.1195135, 38, 4, 423-430, 2017.03, A combined adsorption and mechanical vapor compression system is a reasonable option to reduce the consumption of fossil fuels for air conditioning by utilizing waste heat. Performance predictions of combined adsorption and mechanical vapor compression systems require detailed dynamic modeling because the transitional characteristics explain the nature of the adsorption system. It is, however, desirable to simplify the model for practical use at engineering stages. Since the mechanical vapor compression system is based on the steady-state thermodynamic cycle, a semi-steady-state modeling of adsorption cycles would be functional for analysis of combined systems. In our study, the analytical solution of transient simulation for adsorption cycles was combined with a steady-state mathematical model of the mechanical vapor compression system. The performance of the combined system was analyzed based on the model developed, taking into account the cycle time of the adsorption cycle. The results show the performance characteristics as well as the energy-saving potential of the combined system.. |
| 41. |
Skander Jribi, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Shinnosuke Maeda, Tomohiro Maruyama, CFD simulation and experimental validation of ethanol adsorption onto activated carbon packed heat exchanger, INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID, 10.1016/j.ijrefrig.2016.10.019, 74, 345-353, 2017.02, Experimental validation of simulated adsorber/desorber beds for sorption cooling applications is essential to obtain reliable results. We have conducted rigorous simulation of the adsorption process occurring in a finned tube adsorber utilizing 2D-axisymmetric geometry. The adsorber uses activated carbon ethanol as adsorbent refrigerant pair. It is cooled with water at nearly 30 and experiencing a sharp pressure increase of ethanol from 0.95 kPa initially to 6 kPa. The simulated temperatures at adsorbent thicknesses of 0, 1, 5 and 10 mm from tube outer diameter showed an increase in adsorbent temperature up to 20 degrees C from its initial temperature. They were slightly higher at start of adsorption and were consistent with experimental data at higher flow time. The validated CFD model will serve as a base for evaluating and optimizing activated carbon ethanol adsorption cooling cycle. It can be extended also to different adsorber designs and other adsorbent adsorbate pairs. (C) 2016 Elsevier Ltd and IIR. All rights reserved.. |
| 42. |
Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Refrigerant distribution in horizontal headers with downward minichannel-branching conduits: Experiment, empirical correlation and two-phase flow pattern map, EXPERIMENTAL THERMAL AND FLUID SCIENCE, 10.1016/j.expthermflusci.2016.09.011, 81, 430-444, 2017.02, The system energy efficiency will decline with the decrease of evaporator capacity because the use of more branches in evaporators increases maldistribution. This paper presents experimental study of several design options for downward flow to reduce the maldistribution. Two-phase flow distribution in a header type evaporator applied for CO2 have been experimentally investigated because the refrigeration system based on carbon dioxide (CO2) as a refrigerant is near ideal. Since the CO2 system works around critical pressure, an alternative method to predict the flow distribution of CO2 header type evaporator is inevitable. R134a is used as the alternative working fluid in the present study. Similarity hypothesis between CO2 and R134a is applied (refer to Wijayanta et al., 2016). R134a headers are tested and the experimental work is applicable to CO2. The R134a experiments were conducted at saturation temperature of about 21 degrees C, refrigerant mass flow range between 10 and 30 kg/h which corresponds to about 44 and 130 kg/m(2) sin the 9 mm i.d. header, and average vapor quality in the test section inlet of about 0.1-0.4. The test section consists of a horizontal header with 3 and 6 vertically downward replaceable branching conduits. The vapor-liquid phase mass flows enter into the branches are measured to propose the configuration of the header that has the minimum maldistribution. Empirical correlation of the vapor liquid distribution is developed. Estimated CO2 distribution for the proper header is determined based on R134a experimental data using the similarity hypothesis. The developed flow pattern map for R134a and CO2 is also proposed. (C) 2016 Elsevier Inc. All rights reserved.. |
| 43. |
Agung Tri Wijayanta, 宮崎 隆彦, 小山 繁, Refrigerant distribution in horizontal headers with downward minichannel-branching conduits: Experiment, empirical correlation and two-phase flow pattern map, 81, 430-444, 2017.01. |
| 44. |
Takahiko Miyazaki, Jin Miyawaki, Tomonori Ohba, Seong-Ho Yoon, Bidyut Baran Saha, Shigeru Koyama, Study toward high-performance thermally driven air-conditioning systems, 1st International Conference on Engineering, Science and Nanotechnology 2016, ICESNANO 2016
International Conference on Engineering, Science and Nanotechnology 2016, ICESNANO 2016, 10.1063/1.4968250, 1788, 2017.01, The Adsorption heat pump is a technology for cooling and heating by using hot water as a driving heat source. It will largely contribute to energy savings when it is driven by solar thermal energy or waste heat. The system is available in the market worldwide, and there are many examples of application to heat recovery in factories and to solar cooling systems. In the present system, silica gel and zeolite are popular adsorbents in combination with water refrigerant. Our study focused on activated carbon-ethanol pair for adsorption cooling system because of the potential to compete with conventional systems in terms of coefficient of performance. In addition, activated-ethanol pair can generally produce larger cooling effect by an adsorption-desorption cycle compared with that of the conventional pairs in terms of cooling effect per unit adsorbent mass. After the potential of a commercially available activated carbon with highest level specific surface area was evaluated, we developed a new activated carbon that has the optimum pore characteristics for the purpose of solar or waste heat driven cooling systems. In this paper, comparison of refrigerants for adsorption heat pump application is presented, and a newly developed activated carbon for ethanol adsorption heat pump is introduced.. |
| 45. |
Muhammad H. Mahmood, Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, Valeriy S. Maisotsenko, Overview of the Maisotsenko cycle - A way towards dew point evaporative cooling, RENEWABLE & SUSTAINABLE ENERGY REVIEWS, 10.1016/j.rser.2016.08.022, 66, 537-555, 2016.12, The Maisotsenko Cycle (M-Cycle) is a thermodynamic conception which captures energy from the air by utilizing the psychrometric renewable energy available from the latent heat of water evaporating into the air. The cycle is well-known in the air-conditioning (AC) field due to its potential of dew-point evaporative cooling. However, its applicability has been recently expanded in several energy recovery applications. Therefore, the present study provides the overview of M-Cycle and its application in various heating, ventilation, and air-conditioning (HVAC) systems; cooling systems; and gas turbine power cycles. Principle and features of the M-Cycle are discussed in comparison with conventional evaporative cooling, and consequently the thermodynamic limitation of the cycle is highlighted. It is reported that the standalone M-Cycle AC (MAC) system can achieve the AC load efficiently when the ambient air humidity is not so high regardless of ambient air temperature. Various modifications in MAC system design have been reviewed in order to investigate the M-Cycle applicability in humid regions. It is found that the hybrid, ejector, and desiccant based MAC systems enable a huge energy saving potential to achieve the sensible and latent load of AC in humid regions. Similarly, the overall system performance is significantly improved when the M-Cycle is utilized in cooling towers and evaporative condensers. Furthermore, the M-Cycle conception in gas turbine cycles has been realized recently in which the M-Cycle recuperator provides not only hot and humidified air for combustion but also recovers the heat from the turbine exhaust gases. The M-Cycle nature helps to provide the cooled air for turbine inlet air cooling and to control the pollution by reducing NOx formation during combustion. The study reviews three distinguished Maisotsenko gas turbine power cycles and their comparison with the conventional cycles, which shows the M-Cycle significance in power industry. (C) 2016 Elsevier Ltd. All rights reserved.. |
| 46. |
Skander Jribi, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Shinnosuke Maeda, Tomohiro Maruyama, Corrected adsorption rate model of activated carbon-ethanol pair by means of CFD simulation, INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID, 10.1016/j.ijrefrig.2016.08.004, 71, 60-68, 2016.11, The adsorption rate is an important parameter for accurate performance estimation of adsorbent-refrigerant based adsorption cooling cycles. Here, we have investigated the response of two adsorption kinetics models of activated carbon-ethanol pair by means of CFD simulation. The isothermal assumption used in estimating the diffusion time constant of Fickian diffusion and linear driving force (LDF) models led to divergence and underestimated adsorption uptakes, respectively. By including the simulated adsorbent temperature profile in fitting of LDF model to experimental data, we assessed the non-isothermal diffusion time constants which were 2.5 to 5 times higher than those evaluated previously with isothermal assumption. The goodness of fitting, evaluated with coefficient of determination (R-2), improved and became higher than 0.95 from 0.73 initially. The developed non isothermal LDF equation allows accurate heat and mass transfer simulations and performance optimization of large scale adsorption/desorption bed employing activated carbon ethanol pair for adsorption cooling applications. (C) 2016 Elsevier Ltd and IIR. All rights reserved.. |
| 47. |
Animesh Pal, Ibrahim I. EI-Sharkawy, Bidyut Baran Saha, Skander Jribi, Takahiko Miyazaki, Shigeru Koyama, Experimental investigation of CO2 adsorption onto a carbon based consolidated composite adsorbent for adsorption cooling application, APPLIED THERMAL ENGINEERING, 10.1016/j.applthermaleng.2016.08.031, 109, 304-311, 2016.10, Adsorption of carbon dioxide onto highly porous activated carbon based consolidated composite adsorbent has been experimentally investigated. Experiments have been conducted at temperatures of 30, 50, 70 degrees C and pressures up to 7 MPa using magnetic suspension adsorption measurement unit. The innovative adsorption isotherms data have been correlated using three isotherm models namely, Langmuir, Toth, and modified Dubinin-Astakhov (D-A). The studied models successfully fitted with the experimental data and Toth isotherm model shows a better fitting. Results showed that the volumetric adsorption capacity of CO2 onto the studied consolidated composite is higher than that of CO2 onto parent activated carbon powder (Maxsorb III). The isosteric heat of adsorption of the studied pairs has been calculated from isotherm data. The performance of ideal adsorption cooling cycle, employing consolidated composite adsorbent/CO2 pair, has also been simulated at three different evaporator temperatures, namely 5, 10 and 15 degrees C along with a coolant temperature of 25 degrees C and heat source temperatures ranging from 45 to 90 degrees C. The estimated thermodynamic parameters and isotherm data are important for further development of CO2 based adsorption cooling systems. (C) 2016 Elsevier Ltd. All rights reserved.. |
| 48. |
Animesh Pal, Ibrahim I. El-Sharkawy, SAHA BIDYUT BARAN, Khairul Habib, 宮崎 隆彦, 小山 繁, Thermodynamic analysis of adsorption cooling cycle using consolidated composite adsorbents-ethanol pairs, 11, 20, 12234-12238, 2016.10. |
| 49. |
Agung Tri Wijayanta, Takahiko Miyazaki, Shigeru Koyama, Liquid-vapor phase distribution in horizontal headers with upward minichannel-branching conduits, EXPERIMENTAL THERMAL AND FLUID SCIENCE, 10.1016/j.expthermflusci.2016.03.021, 76, 264-274, 2016.09, Since the refrigeration system based on carbon dioxide (CO2) as a refrigerant is near ideal, liquid-vapor phase distribution in a header type evaporator applied for CO2 has been experimentally investigated. The test section consists of a horizontal header and 3, 6 or 8 vertically upward replaceable branching conduits. The header is made of transparent polyvinyl chloride (PVC) resin for observing the flow regime, and each conduit is composed of an aluminum disk plate and an aluminum minichannel-branching conduit. In order to develop the lowest maldistribution header, several headers with various insertion depths are examined. Since the CO2 system operates at around the supercritical conditions, it is a little bit difficult to observe the flow regime for CO2 at high pressure, therefore, R134a is used as the alternative working fluid in this study. Similarity hypothesis between CO2 and R134a is proposed. The modified Baker flow pattern map (refer to Scott, 1963) is applied to define the equivalent experimental conditions for both R134a and CO2. R134a headers are tested and the experimental work is applicable to CO2. The R134a experiments were conducted at saturation temperature of about 21 degrees C, refrigerant mass flow range between 10 and 30 kg/h which corresponds to about 44 and 130 kg/m(2) s in the 9 mm i.d. header, and average vapor quality in the test section inlet of about 0.1, 0.2, 0.3 and 0.4. The R134a vapor-liquid phase mass flows entering into the branches were measured. The predicted flow regimes at each branch inlet in the header, predicted using flow pattern map in the form of vapor quality as the abscissa versus mass velocity as the ordinate refer to Wojtan et al. (2005), were utilized to understand the observation of phase separation. The liquid-vapor phase distribution of CO2 was estimated based on the R134a experimental result. (C) 2016 Elsevier Inc. All rights reserved.. |
| 50. |
Muhammad Sultan, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut B. Saha, Shigeru Koyama, Tomohiro Maruyama, Shinnosuke Maeda, Takashi Nakamura, Water vapor sorption kinetics of polymer based sorbents: Theory and experiments, APPLIED THERMAL ENGINEERING, 10.1016/j.applthermaleng.2016.05.192, 106, 192-202, 2016.08, Water vapor sorption kinetics of two polymer based sorbents has been experimentally measured at adsorption temperatures of 20, 30, 50, 70 and 80 degrees C using a magnetic suspension adsorption measurement unit. The experimental data is employed to commonly known adsorption kinetics approximations i.e. Linear driving force (LDF) model, Fickian diffusion (FD) model, and Semi-infinite model. All these models could not approximate the adsorption kinetics of polymer based sorbents, however, the LDF model is modified which successfully predicts the experimental kinetics for short-time and long-time estimation. For both sorbents, the diffusion time constant has been calculated at each adsorption temperature, and consequently, activation energy and pre-exponential constant are found from Arrhenius plot. The variation of diffusion time constant with relative pressure and adsorption temperature is discussed in relation with typical behavior of polymer/water pairs. (C) 2016 Elsevier Ltd. All rights reserved.. |
| 51. |
Takahiko Miyazaki, SAHA BIDYUT BARAN, 小山 繁, Analytical Model of a Combined Adsorption Cooling and Mechanical Vapor Compression Refrigeration System, Heat Transfer Engineering, 10.1080/01457632.2016.1195135, 2016.06. |
| 52. |
Muhammad Sultan, Muhammad H. Mahmood, 宮崎 隆彦, 小山 繁, Zahid M. Khan, Close and open cycle adsorption kinetics: Development of correlation for desiccant air-conditioning, 35, 1, 1-8, 2016.06. |
| 53. |
I. Gusti Agung Bagus Wirajati, Yuki Ueda, Atsushi Akisawa, Takahiko Miyazaki, Cycle Optimization on Reheat Adsorption Cycle Applying Fixed Chilled Water Outlet Temperature, HEAT TRANSFER ENGINEERING, 10.1080/01457632.2015.1066650, 37, 7-8, 606-615, 2016.05, This study investigated the cycle optimization of four-bed, silica gel-water adsorption with reheat cycle, where the desorber (upper bed) and adsorber (lower bed) always interact with the condenser and evaporator, to exploit a low heat-source temperature. In a previous study, the performance of a reheat cycle with chilled water outlet temperature fixed at 9 degrees C was observed without considering the cycle optimization. Maintaining a constant chilled water outlet temperature is also of equal importance to improve the conversion efficiency so that maximum cooling capacity can be derived. In this paper, a simulation model of reheat adsorption cycles is developed to analyze the optimization of the cycle time, including adsorption/desorption time, mass recovery time, and preheating/precooling time, with chilled water outlet temperature fixed. The reheat working principle is also introduced. The proposed cycle is compared with the four-bed versison without reheat cycle in terms of coefficient of performance (COP) and cooling capacity. The result shows that the performance of a reheat cycle is superior to that of four-bed version without reheat, especially for low heat-source temperature. For low heat-source temperature (55-65 degrees C) both COP and cooling capacity of the reheat cycle with optimization were raised significantly compared to the high heat-source temperature (70-80 degrees C).. |
| 54. |
Bidyut Baran Saha, Takahiko Miyazaki, Selected Papers from the International Symposium on Innovative Materials for Processes in Energy Systems 2013 (IMPRES2013): Part I, HEAT TRANSFER ENGINEERING, 10.1080/01457632.2015.1066645, 37, 7-8, 603-605, 2016.05. |
| 55. |
Ibrahim I. El-Sharkawy, Animesh Pal, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, A study on consolidated composite adsorbents for cooling application, APPLIED THERMAL ENGINEERING, 10.1016/j.applthermaleng.2015.12.105, 98, 1214-1220, 2016.04, In this study, consolidated composite adsorbents which are combinations of a highly porous activated carbon powder (Maxsorb III), expanded graphite (EG) and binder have been developed and characterized. Porous properties of the developed composite adsorbents have been investigated experimentally using Nitrogen adsorption. Adsorption equilibrium uptakes of ethanol onto composite adsorbents have been measured and correlated using suitable adsorption isotherm models. Thermal conductivity of the prepared adsorbents has also been measured using the NETZSCH LFA 457 MicroFlash system. Experimental results show that the adsorption equilibrium capacity of ethanol onto consolidated composite (70% Maxsorb III, 20% EG, 10% binder) is 0.89 kg kg(-1) which is about 74% of the maximum adsorption uptake of parent Maxsorb III/ethanol pair. This is clear evidence that the binder doesn't sacrifice the adsorption capacity of Maxsorb III of consolidated composites. It is also found that the thermal conductivity of the developed consolidated adsorbents increased to 11 times that of Maxsorb III powder. (C) 2015 Elsevier Ltd. All rights reserved.. |
| 56. |
JRIBI SKANDER, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Shinnosuke Maeda, Tomohiro Maruyama, Non-isothermal adsorption rate model of activated carbon-ethanol pair for solar cooling applications estimated through CFD simulation, Proceedings of the 7th International Renewable Energy Congress, 2016.03. |
| 57. |
JRIBI SKANDER, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Shinnosuke Maeda, Tomohiro Maruyama, CFD Simulation of Ethanol Adsorption onto Activated Carbon for Adsorption Cooling Applications, Proceedings of the First Pacific Rim Thermal Engineering Conference, PRTEC-14747, 2016.03. |
| 58. |
Muhammad Sultan, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Steady-state investigation of water vapor adsorption for thermally driven adsorption based greenhouse air-conditioning system, RENEWABLE ENERGY, 10.1016/j.renene.2015.09.015, 86, 785-795, 2016.02, In the present study, water vapor adsorption onto silica-gel, activated carbon powder (ACP) and activated carbon fiber (ACF) has been experimentally measured at 20, 30 and 50 degrees C using a volumetric method based adsorption measurement apparatus for greenhouse air-conditioning (AC). The Guggenheim-Anderson-De Boer and Dubinin-Astakhov adsorption models are used to fit the adsorption data of silica-gel and ACP/ACF, respectively. The isosteric heat of adsorption is determined by Clausius-Clapeyron relationship. The adsorbents are evaluated for low-temperature regeneration with aim to develop solar operated AC system for greenhouses. Ideal growth zone for agricultural products is determined by which the steady-state desiccant AC cycle is evaluated on the psychometric chart and adsorption isobars.
Steady-state moisture cycled (MCSS) by each adsorbent is determined for demand category-I, II and III which are based on 60%, 40% and 20% relative humidity of dehumidified air, respectively. In case of demand category-I, the ACP enables maximum MCSS at all regeneration temperatures (T-reg), ideally sitting at 47 degrees C. The ACF enables double MCSS as compared to silica-gel during demand category-II at T-reg >= 59 degrees C. However, the silica-gel is found the only applicable adsorbent for the demand category-III. (C) 2015 Elsevier Ltd. All rights reserved.. |
| 59. |
Marzia Khanam, Kazuhide Ito, Takahiko Miyazaki, Simulation of gas cooler of CO2 heat pump water heater for different tube geometries, Proceedings of the 3rd International Workshop on Heat Transfer Advances for Energy Conservation and Pollution Control, Paper ID 1176, 2015.10. |
| 60. |
Daishiro Nakamoto, Takahiko Miyazaki, Shigeru Koyama, Bidyut Baran Saha, Study on adsorption characteristics of activated carbon - R 32 pair for heat pump application, Proceedings of the 3rd International Workshop on Heat Transfer Advances for Energy Conservation and Pollution Control, Paper ID 1177, 2015.10. |
| 61. |
Fauziah Jerai, Takahiko Miyazaki, Shigeru Koyama, Bidyut Baran Saha, S. Maeda, T. Onda, T. Maruyama, Optimum cycle time for one bed operation of activated carbon-ethanol pair adsorption cooling system, Proceedings of the 3rd International Workshop on Heat Transfer Advances for Energy Conservation and Pollution Control, Paper ID 1215, 2015.10. |
| 62. |
Takahiko Miyazaki, Shigeru Koyama, Valeriy S. Maisotsenko, The Maisotsenko Cycle as a Heat and Mass Recovery Device for Co-Generation, Proceedings of the 4th International Conference on Microgeneration and Related Technologies, Paper ID 0088, 2015.10. |
| 63. |
JERAI Fauziah, MIYAZAKI Takahiko, SAHA Bidyut Baran, KOYAMA Shigeru, Importance of Pre-cooling and Pre-heating on Performances of One Bed Adsorption Cooling Systems with Activated Carbon-ethanol Pair (創立90周年記念号) -- (特集 再生可能エネルギーと冷凍空調), 日本冷凍空調学会論文集, 10.11322/tjsrae.15-26RE, 32, 3, 381-392, 2015.09, This paper presents theoretical and experimental investigation of an adsorption cooling system to predict the cycle performance of one bed adsorber based on the equilibrium condition. For this particular study, activated carbon-ethanol pair was chosen as the adsorbent-refrigerant pair because of a high adsorption capacity of activated carbons against ethanol. The experiment was conducted on five different pre-cooling and pre-heating settings. The experiments carried out were divided to two sections. First, the preliminary experiments were carried out on two extreme conditions. For the first extreme condition, the adsorption and desorption process were carried out without pre-cooling and pre-heating. Whilst for the second extreme condition, the adsorbent was pre-cooled and pre-heated until the adsorbent reach adsorption and desorption temperature. Then the experiments were carried out with three different time of pre-cooling/pre-heating time which was selected based on the preliminary experiments. The heat balance were analyzed critically and the optimum cycle time, namely the pre-cooling and pre-heating time for each adsorption and desorption process is discussed by identifying the suitable adsorbent pressure and temperature of the system. . |
| 64. |
Muhammad Sultan, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Valeriy S. Maisotsenko, Steady-state analysis on thermally driven adsorption air-conditioning system for agricultural greenhouses, Procedia Engineering, 118, 185-192, 2015.08. |
| 65. |
Muhammad Sultan, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Optimization of adsorption isotherm taxonomy for open-cycle desiccant air-conditioning applications, Proceedings of the 24th IIR International Congress of Refrigeration (ICR2015), E1-Tu-3, 2015.08. |
| 66. |
JRIBI SKANDER, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Transient simulation of finned tube type adsorber employing activated carbon-ethanol as adsorbent-refrigerant pair, Proceedings of the 24th IIR International Congress of Refrigeration (ICR2015), B1-We-2b, 2015.08. |
| 67. |
Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Adsorption characteristics of ethanol onto promising adsorbents for adsorption cooling applications, Proceedings of the 24th IIR International Congress of Refrigeration (ICR2015), E2-Th-4, 2015.08. |
| 68. |
Muhammad Sultan, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, An overview of solid desiccant dehumidification and air conditioning systems, RENEWABLE & SUSTAINABLE ENERGY REVIEWS, 10.1016/j.rser.2015.02.038, 46, 16-29, 2015.06, To address the importance of desiccant air-conditioning (DAC) systems, this paper discusses the comparison between DAC and conventional vapor compression air-conditioning (VAC). Performance and economic feasibility (PEF) of the system is conferred with reference literature to correlate the types of DAC system from the perspective of energy saving and system payback period. The present study provides three examples of existing desiccant cooling systems namely (i) standalone DAC system, (ii) single-stage hybrid DAC system, and (iii) two-stage hybrid DAC system, which highlight their importance under different environmental conditions. This study provides scientific and experimental supports on how the standalone or hybrid desiccant cooling can be a supplement to the exiting VAC system. (C) 2015 Elsevier Ltd. All rights reserved.. |
| 69. |
Muhammad Sultan, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut B. Saha, Shigeru Koyama, Tomohiro Maruyama, Shinnosuke Maeda, Takashi Nakamura, Insights of water vapor sorption onto polymer based sorbents, ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY, 10.1007/s10450-015-9663-y, 21, 3, 205-215, 2015.04, Two polymer based sorbents PS-I and PS-II are analyzed for water sorption applications. Adsorption/desorption isotherms of water vapor onto PS-I and PS-II have been experimentally measured using a magnetic suspension adsorption measurement unit for adsorber temperature ranges 20-80 A degrees C and evaporator temperature ranges 2-73 A degrees C. The equilibrium adsorption uptake of water vapors corresponding to saturation condition at 30 A degrees C by PS-I and PS-II was found nearly 2 and 2.5 times higher than the conventional silica-gel, respectively. Adsorption data has been analyzed for various adsorption models which include Brunauer-Emmett-Teller (BET); Freundlich; Dubinin-Astakhov (D-A); Oswin; and Guggenheim-Anderson-de Boer (GAB) model. The GAB and BET model give the good fit for relative pressure range of 0.10-0.90 and 0.05-0.35, respectively. At all adsorption temperatures of both sorbents, the monolayer uptake by the GAB model is found higher than the BET model. Effect of adsorption potential on adsorption uptake is highlighted in relation with water vapor adsorption mechanism. The isosteric heat of water vapor adsorption is determined for both sorbents using Clausius-Clapeyron equation.. |
| 70. |
Abul Fazal Mohammad Mizanur Rahman, Yuki Ueda, Atsushi Akisawa, Takahiko Miyazaki, Bidyut Baran Saha, Study of a silica gel-water-based three-bed dual-mode adsorption cooling cycle, Heat Transfer Research, 10.1615/HeatTransRes.2014007215, 46, 3, 213-232, 2015.03. |
| 71. |
Ibrahim I. El-Sharkavvy, Kutub Uddin, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Hyun-Sig Kil, Seong-Ho Yoon, Jin Miyawaki, Adsorption of ethanol onto phenol resin based adsorbents for developing next generation cooling systems, INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 10.1016/j.ijheatmasstransfer.2014.10.012, 81, 171-178, 2015.02, Adsorption characteristics of ethanol onto two promising adsorbents have been investigated for developing high performance adsorption chillers. These new adsorbents are based on spherical phenol resin treated with different mass ratios of KOH named as KOH4-PR and KOH6-PR. Experimental adsorption isotherm measurements show that the adsorption capacity of KOH4-PR/ethanol is as high as 1.43 kg kg(-1) whilst one kg of KOH6-PR able to adsorb nearly about 2 kg of ethanol. To the best of our knowledge, the studied adsorbents possess the highest ethanol uptake. Moreover, it is found that the KOH4-PR/ethanol pair has notably high adsorption kinetics at the lower range of adsorption temperatures. Experimental measurements of adsorption uptake and adsorption uptake rate of the studied pairs have been analyzed and isosteric heats of adsorption have also been extracted. (C) 2014 Elsevier Ltd. All rights reserved.. |
| 72. |
Bidyut Baran Saha, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Shigeru Koyama, Stefan K. Henninger, Annika Herbst, Christoph Janiak, Ethanol adsorption onto metal organic framework: Theory and experiments, ENERGY, 10.1016/j.energy.2014.11.022, 79, 363-370, 2015.01, This paper presents experimental and theoretical investigations of adsorption characteristics of ethanol onto metal organic framework namely MIL-101Cr. Adsorption isotherms and kinetics of the studied pair have been measured gravimetrically using a magnetic suspension adsorption measurement unit and volumetrically employing a Quantachrome Autosorb iQ MP machine. The present experiments have been conducted within relative pressures between 0.1 and 0.9 and adsorption temperatures ranging from 30 to 70 degrees C, which are suitable for adsorption cooling applications. Adsorption isotherm data exhibit that 1 kg of MIL-101Cr can adsorb as high as 1.1 kg of ethanol at adsorption temperature of 30 degrees C, and the Toth equation has been used to fit the experimentally measured data. As of the experimentally measured adsorption uptake rate data, the Fickian diffusion model is found to be suitable. These data are essential for designing a new generation of adsorption chiller. (C) 2014 Elsevier Ltd. All rights reserved.. |
| 73. |
Hayato Imamura, Takahiko Miyazaki, Ibrahim I. El-Sharkawy, Bidyut Baran Saha, Shigeru Koyama, Dynamic simulation of adsorption heat pumps with surface treated activated carbon-ethanol pairs, Proceedings of the International Workshop on Environment & Engineering 2014, 415, 2014.11. |
| 74. |
Tsutomu Sumii, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Study on adsorption heat pump cycles using activated carbon-R32 pair, Proceedings of the International Workshop on Environment & Engineering 2014, 416, 2014.11. |
| 75. |
Kutub Uddin, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Hyun-Sig Kil, Jin Miyawaki, Seong-Ho Yoon, Adsorption characteristics of ethanol onto functional activated carbons with controlled oxygen content, APPLIED THERMAL ENGINEERING, 10.1016/j.applthermaleng.2014.03.062, 72, 2, 211-218, 2014.11, The present study aims to investigate adsorption characteristics of ethanol onto activated carbon powders namely; parent Maxsorb III and surface treated Maxsorb III with controlled oxygen content. Experiments have been conducted gravimetrically using a magnetic suspension adsorption measurement unit. The measurements have been conducted within evaporator temperatures range from -14 to 77 degrees C and adsorption temperatures between 20 and 80 degrees C The Dubinin-Astakhov (D-A) adsorption model is found to be suitable to correlate the adsorption isotherm data. The isosteric heat of adsorption of the assorted adsorbent/refrigerant pairs has been estimated using Clausius-Clapeyron and the D-A equations. Effect of the refrigerant purity on the adsorption characteristics of the adsorbent/refrigerant pair is also discussed. The data extracted from this study are useful for the design of adsorption cooling, refrigeration and heat pump systems. (C) 2014 Elsevier Ltd. All rights reserved.. |
| 76. |
Muhammad Sultan, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Experimental Study on Carbon Based Adsorbents for Greenhouse Dehumidification, Evergreen - Joint Journal of Novel Carbon Resource Sciences & Green Asia Strategy, 1, 2, 5-11, 2014.09. |
| 77. |
Takahiko Miyazaki, Ibrahim I. El-Sharkawy, Bidyut Baran Saha, Shigeru Koyama, Optimized Performance of One-Bed Adsorption Cooling System, Proceedings of the 15th International Refrigeration and Air Conditioning Conference at Purdue, 2429, 2014.07. |
| 78. |
Kutub Uddin, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Thermodynamic Analysis of Adsorption Refrigeration Cycles Using Parent and Surface Treated Maxsorb III/Ethanol Pairs, Proceedings of the 15th International Refrigeration and Air Conditioning Conference at Purdue, 2456, 2014.07. |
| 79. |
Fauziah Jerai, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Shinnosuke Maeda, Tadayoshi Onda, Tomohiro Maruyama, ANALYSIS ON ADSORBER PERFORMANCE FOR THERMALLY DRIVEN CHILLERS, Proceedings of the Grand Renewable Energy 2014, P-Th-38, 2014.07. |
| 80. |
Ibrahim I. El-Sharkawy, Kutub Uddin, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Jin Miyawaki, Seong-Ho Yoon, Adsorption of ethanol onto parent and surface treated activated carbon powders, INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 10.1016/j.ijheatmasstransfer.2014.02.046, 73, 445-455, 2014.06, In this paper, adsorption isotherms and kinetics of ethanol onto highly porous activated carbon powders have been investigated. Adsorbents used in the present study are (i) parent Maxsorb III, (ii) KOH-H-2 treated Maxsorb III, and (iii) H-2 treated Maxsorb Ill. Adsorption isotherms and kinetics of the assorted pairs have been measured using magnetic suspension adsorption measurement unit (MSB-VG-S2). Experiments have been conducted across assorted adsorption temperatures that are useful for the operation of adsorption chillers. The Dubinin-Astakhov equation is used to fit adsorption isotherms of parent Maxsorb III/ethanol and KOH-H-2 treated Maxsorb III pairs whilst the Dubinin-Radushkevich isotherm model is found to be more suitable for fitting of adsorption uptake of H-2-treated Maxsorb III/ethanol pair. Adsorption kinetics of assorted pairs are presented by the Fickian diffusion model. Experimental results show that, among the assorted pairs, H-2 treated Maxsorb III/ethanol pair possesses the highest adsorption equilibrium uptake. However, the diffusion time constant of KOH-H-2 treated Maxsorb III is found to be higher than that of other two studied pairs. (C) 2014 Elsevier Ltd. All rights reserved.. |
| 81. |
Takahiko Miyazaki, Bidyut Baran Saha, Ibrahim I. El-Sharkawy, Shigeru Koyama, Performancesimulationofadsorptionrefrigeration/heatpumpwithsilicagel-waterandactivatedcarbon-ethanol combinations, Proceedings of the 7th Asian Conference on Refrigeration and Air Conditioning, 503, 2014.05. |
| 82. |
Muhammad Sultan, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, A study on adsorption of water onto carbon based adsorbents, Proceedings of the 7th Asian Conference on Refrigeration and Air Conditioning, 534, 2014.05. |
| 83. |
Ibrahim I. El-Sharkawy, Kutub Uddin, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Stefan K. Henninger, Characterization of adsorbent/refrigerant pairs for developing high performance adsorption cooling systems, Proceedings of the 7th Asian Conference on Refrigeration and Air Conditioning, 258, 2014.05. |
| 84. |
I Gusti Agung Bagus Wirajati, Yuki Ueda, Atsushi Akisawa, Takahiko Miyazaki, The Performance of Three Bed Re-heat Combined Adsorption Chiller, Proceedings of the International Sorption Heat Pump Conference 2014, #7, 2014.04. |
| 85. |
Takahiko Miyazaki, Ibrahim I. El-Sharkawy, Bidyut Baran Saha, Shigeru Koyama, Performance Prediction of Adsorption Heat Pump Systems Using Activated Carbon and R 32 Pair, Proceedings of the International Sorption Heat Pump Conference 2014, #92, 2014.04. |
| 86. |
Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, Bidyut Baran Saha, Utilization of Desiccant Air-Conditioning System for Improvement in Greenhouse Productivity: A Neglected Area of Research in Pakistan, International Journal of Environment, 4, 1, 1-10, 2014.03. |
| 87. |
Double Effect Adsorption Refrigeration Cycle Using Silica gel-FAM Z01/Water Pair. |
| 88. |
Kutub Uddin, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Thermodynamic Analysis of Adsorption Cooling Cycle using Ethanol-Surface treated Maxsorb III Pairs, Evergreen - Joint Journal of Novel Carbon Resource Sciences & Green Asia Strategy, 1, 1, 25-31, 2014.03. |
| 89. |
A.F.M.Mizanur Rahman, Y.Ueda, A.Akisawa, T.Miyazaki, B.B.Saha, Design and performance of Four-Stage Adsorption System, International Journal of Research in Engineeringand Science (IJRES), 2, 1, 1-10, 2014.01. |
| 90. |
Kutub Uddin, Takahiko Miyazaki, Shigeru Koyama, Bidyut Baran Saha, Performance investigation of adsorption – compression hybrid refrigeration systems, International Journal of Air-Conditioning and Refrigeration, 21, 4, 1350024, 2013.11. |
| 91. |
Kutub Uddin, Ibrahim I. El-Sharkawy, Takahiko Miyazaki, Bidyut Baran Saha, Shigeru Koyama, Hyun Sig Kil, Jin Miyawaki, Seongho YOON, Adsorption of ethanol onto carbon based adsorbents, Proceedings of the 11th Japan-China-Korea Joint Symposium on Cabon Saves the Earth, 2013.11. |
| 92. |
Bidyut Baran Saha, Takahiko Miyazaki, Shigeru Koyama, Adsorption cooling cum desalination cycles, Proceedings of the 11th Japan-China-Korea Joint Symposium on Cabon Saves the Earth, 2013.11. |
| 93. |
Takahiko Miyazaki, Shigeru Koyama, Bidyut Baran Saha, Analytical model of a combined adsorption cooling and mechanical vapor compression refrigeration system, Proceedings of the 6th International Meeting on Advanced Thermofluids, 2013.11. |
| 94. |
Abul Fazal Mohammad Mizanur Rahman, Takahiko Miyazaki, Yuki Ueda, Bidyut Baran Saha, Atsushi Akisawa, Performance Comparison of Three-Bed Adsorption Cooling System With Optimal Cycle Time Setting, HEAT TRANSFER ENGINEERING, 10.1080/01457632.2012.753571, 34, 11-12, 938-947, 2013.09, This article presents the optimal cycle time and performance of two different types of silica gel-water-based three-bed adsorption chillers employing mass recovery with heating/cooling scheme. A new simulation program has been developed to analyze the effect of cycle time precisely on the performance of the systems. The particle swarm optimization (PSO) method has been used to optimize the cycle time and then the optimum performances of two chillers are compared. Sensitive analysis of cycle time has been conducted using the contour plot of specific cooling power (SCP) with driving heat source temperature at 80 degrees C. It is found that the center point of the contour indicates the maximum SCP value and optimal cycle time, which are comparable with the quantitative values obtained for the PSO method. Both three-bed mass recovery adsorption cycles can produce effective cooling at heat source temperature as low as 50 degrees C along with a coolant at 30 degrees C. The optimal SCP is similar for both cycles and is greater than that of the conventional two-bed adsorption system employing the same adsorbent-refrigerant pair. Consequently, the proposed comparison method is effective and useful to identify the best performance of adsorption cycles.. |
| 95. |
Ahamed A. Askalany, Bidyut Baran Saha, Kutub Uddin, Takahiko Miyazaki, Shigeru Koyama, Kandadai Srinivasan, Ibrahim M. Ismail, Adsorption isotherms and heat of adsorption of difluoromethane on activated carbons, Journal of Chemical & Engineering Data, 58, 2828-2834, 2013.09. |
| 96. |
I Gusti Agung Bagus Wirajati, Yuki Ueda, Atsushi Akisawa, Takahiko Miyazaki, Cycle optimization on re-heat adsorption cycle applying fixed chilled water outlet temperature, The Proceedings of the IMPRES2013, 59-66, 2013.09. |
| 97. |
Ahmed A. Askalany, Bidyut Baran Saha, Takahiko Miyazaki, Shigeru Koyama, Ibrahim M. Ismail, Modified linear driving force model for accurate approximation of adsorption kinetics experimental data, The Proceedings of the IMPRES2013, 351-355, 2013.09. |
| 98. |
Kutub Uddin, Takahiko Miyazaki, Shigeru Koyama, Bidyut Baran Saha, Hyun Siq Kil, Jin Miyawaki, Seongho YOON, Adsorption kinetics of ethanol onto functional activated carbons with controlled oxygen content, The Proceedings of the IMPRES2013, 356-361, 2013.09. |
| 99. |
Seung Taek Oh, KEISHI KARIYA, Yoshinori Hamamoto, Bidyut Baran Saha, Hideo Mori, Takahiko Miyazaki, Shigeru Koyama, Adsorption of water vapor onto silica gel using innovative compact fin and tube heat exchanger, The Proceedings of the IMPRES2013, 362-367, 2013.09. |
| 100. |
Ibrahim I. El-Sharkawy, Hossam Abdelmeguid, Bidyut Baran Saha, Shigeru Koyama, Takahiko Miyazaki, Performance investigation of a solar-powered adsorption cooling system: a case study for Egypt, The Proceedings of the IMPRES2013, 390-395, 2013.09. |
| 101. |
Takahiko Miyazaki, Ibrahim I. El-Sharkawy, Bidyut Baran Saha, Shigeru Koyama, Study on adsorption cooling system -Fundamental to system evaluation-, Proceedings of the International Conference on Green Energy and Technology, 153, 2013.08. |
| 102. |
Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, Bidyut Baran Saha, Consideration of solid desiccant dehumidification and air conditioning system for greenhouses of Pakistan: A feasibility study, Proceedings of the International Conference on Green Energy and Technology, 185-190, 2013.08. |
| 103. |
Abul Fazal Mohammad Mizanur Rahman, Yuki Ueda, Atsushi Akisawa, Takahiko Miyazaki, Bidyut Baran Saha, Design and Performance of an Innovative Four-Bed, Three-Stage Adsorption Cycle, ENERGIES, 10.3390/en6031365, 6, 3, 1365-1384, 2013.03, The design of a four-bed three-stage adsorption cycle has been proposed to reduce the volume of the six-bed three-stage adsorption cycle. A simulation model for the proposed innovative cycle was developed to analyse the influence of cycle time on the system performance identifying the specific cooling power (SCP) and coefficient of performance (COP). A particle swarm optimization (PSO) technique was used to optimize the cycle time enabling us to maximize the SCP. PSO results showed that the optimal cycle time was decreased with heat source temperature and SCP value was proportional to heat source temperature. It was found that the proposed cycle could be driven by waste heat as low as 40 degrees C, along with coolant at 30 degrees C. Comparative study of optimized result indicated that the proposed cycle increased the performance significantly over a whole range of temperatures from 40 to 70 degrees C and reduced two adsorbent beds, compared to the six-bed three-stage cycle.. |
| 104. |
Naoya Makimoto, Miyazaki Takahiko, Koyama Shigeru, Cyclic performance of adsorption chiller using a compact adsorption heat exchanger, 14th Cross Straits Symposium on Energy and Environmental Science and Technology (14th CSS-EEST), 2013.02. |
| 105. |
Kutub Uddin, Miyazaki Takahiko, Koyama Shigeru, Saha Baran Bidyut, Adsorption isotherms of R134a and R32 onto activated carbons, 14th Cross Straits Symposium on Energy and Environmental Science and Technology (14th CSS-EEST), 2013.02. |
| 106. |
Kutub Uddin, Miyazaki Takahiko, Koyama Shigeru, Saha Baran Bidyut, Thermodynamic analysis of HFCs-ethnol sub-cooler type hybrid refrigeration system, 14th Cross Straits Symposium on Energy and Environmental Science and Technology (14th CSS-EEST), 2013.02. |
| 107. |
Pornpipat Yoosa, Miyazaki Takahiko, Koyama Shigeru, Performance evaluation of desiccant dehumidification and evaporative cooling, 14th Cross Straits Symposium on Energy and Environmental Science and Technology (14th CSS-EEST), 2013.02. |
| 108. |
Takuya Oda, Masakazu Ito, Norihiro Kawasaki, Takahiko Miyazaki, Takao Kashiwagi, Potential estimation of hourly blank storage space and charge loads of EVs using road traffic census and vehicles status, ELECTRICAL ENGINEERING IN JAPAN, 10.1002/eej.22352, 182, 3, 30-38, 2013.02, If both EVs (Electric Vehicles, includes plug-in hybrid electric vehicles) and renewable energies spread in large quantities, it is possible to control the supply fluctuation of renewable energies using the storage battery of EVs. This research sought to show the charge load potential of EVs based on the state of the Japanese passenger car using traffic census results, etc. Furthermore, it tried to show the trend of the storage battery capacity according to time. From the estimated results: (1) the charge electricity of low and middle distance gets a majority of the total charge demand, (2) charge load changes according to time several times, and the minimum load is the number of gigawatt-hours at early morning, (3) if night charge is assumed, the standby charge demand of noon will reach tens of gigawatt-hours, it may have sufficient scale for supply fluctuation control of PVs. Although the present EV is not suitable for long-distance running, these are expected to be 30 or less percent of the total charge demand. The estimated storage capacity potential in this research will not change numbers of times. (c) 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(3): 3038, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22352. |
| 109. |
Abul Fazal Mohammad Mizanur RAHMAN, Yuki UEDA, Atsushi AKISAWA, Takahiko MIYAZAKI, Bidyut Baran SAHA, Innovative Design and Performance of Three-Bed Two-Stage Adsorption Cycle under Optimized Cycle Time, Journal of Environment and Engineering, 10.1299/jee.7.92, 7, 1, 92-108, 2012.12, This paper presents an innovative design of a three-bed two-stage silica gel-water based adsorption cycle aiming to minimize the overall size of four-bed two-stage cycle. One heat exchanger bed was removed from former four-bed two-stage system and operational strategy was taken to increase the adsorption time compare to desorption time in the proposed design. A simulation model for the proposed cycle was developed in order to analyze the influence of cycle time on the performance of the system in terms of specific cooling power (SCP) and coefficient of performance (COP). The cycle time was optimized to obtain the maximum SCP for different heat source temperatures using the particle swarm optimization (PSO) method. Sensitivity analysis of the cycle time was conducted using contour plot of SCP and chilled water outlet temperature for driving heat source temperature at 55°C. Optimize results were compared with the results of four-bed two-stage cycle. It was found that the SCP was increased for the proposed cycle over the whole range of regeneration temperature. The proposed cycle seems advantageous from the economic viewpoint due to its improved performance and reduced volume.. |
| 110. |
全国アンケート調査による太陽光発電システムに関する導入意識とコンジョイント分析. |
| 111. |
Saha Baran Bidyut, Miyazaki Takahiko, Koyama Shigeru, Study on adsorption cooling cycles based on activated carbon and low GWP refrigerant pairs, 10th China-Japan-Korea Joint Symposium on Carbon Materials to Save the Earch, 2012.11. |
| 112. |
Miyazaki Takahiko, Koyama Shigeru, Kutub Uddin, Dynamic simulation on a mechanical/thermal compression hybrid air-conditionning cycle, The 6th Asian conference on Refigeration and Air Conditioning (ACRA2012), 2012.08. |
| 113. |
Takahiko Miyazaki, Shigeru Koyama, Low pressure refrigeration cycle using CO2 refrigerant by adsorption phenomena, Proceedings of the Eighth KSME-JSME Thermal and Fluids Engineering Conference, GST01-003, 2012.03. |
| 114. |
Naoya Makimoto, Takahiko Miyazaki, Shigeru Koyama, The effect of heating water temperature on the performance of an adsorption cooling system using activated carbon power/ethanol pair, Proceedings of the 13th Cross Straits Symposium on Materials, Energy and Environmental Engineering, ETP-2, 2011.11. |
| 115. |
Takahiko Miyazaki, Atsushi Akisawa, Isao Nikai, The cooling performance of a building integrated evaporative cooling system driven by solar energy, ENERGY AND BUILDINGS, 10.1016/j.enbuild.2011.05.004, 43, 9, 2211-2218, 2011.09, The solar chimney is a passive cooling technique to enhance the natural ventilation of buildings. The effect is, however, limited under hot and humid climatic conditions. In the study, the solar chimney was accompanied by a dew-point evaporative cooler. The dew-point evaporative cooler was integrated with the ceiling of a building. The air flow induced by the solar chimney was predicted by simulation, and the cooling effect of the dew-point evaporative cooler was also analyzed by heat and mass transfer simulation. The results showed that the system was capable of coping with internal heat gains of an ordinary office building. In addition, the optimal geometry of the evaporative cooling channel was revealed. (C) 2011 Elsevier B.V. All rights reserved.. |
| 116. |
Mサイクルを用いた建築一体型太陽エネルギー駆動冷房システムによる省エネルギー可能性の評価. |
| 117. |
Takahiko Miyazaki, Yuya Tani, Yuki Ueda, Atsushi Akisawa, The experimental investigation of the dual evaporator type adsorption chiller, Proceedings of the 10th IEA Heat Pump Conference 2011, ID 3.38, 2011.06. |
| 118. |
Takahiko Miyazaki, Isao Nikai, Atsushi Akisawa, Simulation analysis of an open-cycle adsorption air conditioning system − Numeral modeling of a fixed bed dehumidification unit and the maisotsenko cycle cooling unit, International Journal of Energy for a Clean Environment, 12, 2-4, 341-354, 2011.04. |
| 119. |
Marlinda, Aep Saepul Uyun, Takahiko Miyazaki, Yuki Ueda, Atsushi Akisawa, Performance Analysis of a Double-effect Adsorption Refrigeration Cycle with a Silica Gel/Water Working Pair, ENERGIES, 10.3390/en3111704, 3, 11, 1704-1720, 2010.11, A numerical investigation of the double-effect adsorption refrigeration cycle is examined in this manuscript. The proposed cycle is based on the cascading adsorption cycle, where condensation heat that is produced in the top cycle is utilized as the driving heat source for the bottom cycle. The results show that the double-effect cycle produces a higher coefficient of performance (COP) as compared to that of the conventional single-stage cycle for driving temperatures between 100 degrees C and 150 degrees C in which the average cycle chilled water temperature is fixed at 9 degrees C. Moreover, the COP of the double-effect cycle is more than twice that of the single-stage cycle when the temperature reaches 130 degrees C. It is also observed that the adsorbent mass ratio of the high temperature cycle (HTC) to the low temperature cycle (LTC) affects the performance of the double-effect adsorption refrigeration cycle.. |
| 120. |
Atsushi Akisawa, Takahiko Miyazaki, Takao Kashiwagi, Theoretical analysis of the optimal configuration of co-generation systems and competitiveness of heating/cooling technologies, ENERGY, 10.1016/j.energy.2010.06.015, 35, 10, 4071-4078, 2010.10, This study aims at exploiting optimal configurations of technologies combined with co-generation theoretically based on a linear optimization model. With the objective function defining primary energy consumption to be minimized, optimal solutions are derived analytically. They describe the technological configurations as well as associated conditions depending on their final energy demand. An interesting finding is that the essential parameters to determine the configurations are heat, cooling and steam demands normalized by power demand. The optimal solutions are also applied to investigate the competitiveness of co-generation related technologies. The optimal solutions yield critical conditions theoretically, which is useful to understand the priority of the technologies. A sensitivity analysis numerically indicates that absorption chillers can be superior to compression chillers even though the former has lower COP than the latter. Actual data of various types of co-generation are also examined to show the practical competitiveness. (C) 2010 Elsevier Ltd. All rights reserved.. |
| 121. |
T. Nualboonrueng, T. Miyazaki, Y. Ueda, A. Akisawa, The performance of PVT collector in Japan, Renewable Energy 2010, O-Th-1-3, 2010.07. |
| 122. |
H. Sugihara, J. Yamashita, Y. Ikoma, A. Akisawa, T. Miyazaki, Y. Ueda, T. Kashiwagi, Estimation of GY photovoltaic energy generated by rooftop solar panel systems in Japan using GIS data, Renewable Energy 2010, O-Pv-4-2, 2010.07. |
| 123. |
T. Miyazaki, A. Akisawa1, I. Nikai, Study on the Maisotsenko cycle evaporative cooler driven by the solar chimney, Renewable Energy 2010, O-Th-2-4, 2010.07. |
| 124. |
A. Akisawa, M. Ashida, T. Miyazaki, Y. Ueda, M. Horio, Low-cost oriented micro hydropower using motorboat propellers as the hydro turbines, Renewable Energy 2010, O-Sh-2-4, 2010.07. |
| 125. |
A. Akisawa, T. Miyazaki, Y. Ueda, Solar thermal collecting performance with non-imaging fresnel lens to concentrate infrared irradiation, Renewable Energy 2010, P-Th-8, 2010.07. |
| 126. |
A. Akisawa, K. Araki, T. Miyazaki, Y. Ueda, Utilization of wasted heat from refuse incineration with heat transportation by ammonia-water heat pump system, Renewable Energy 2010, P-He-16, 2010.07. |
| 127. |
H. Tasai, T. Miyazaki, A. Akisawa, Characteristics of CIS photovoltaic module, Renewable Energy 2010, OP-14-1, 2010.07. |
| 128. |
Atsushi Akisawa, Takahiko Miyazaki, Yuki Ueda, Kazumichi Araki, Toshitaka Takei, Application of ammonia-water absorption cycle to transfer cooling and heating at ambi- ent temperature, Proceedings of the 5th Asian Conference on Refrigeration and Air-conditioning, A1-023, 2010.06. |
| 129. |
Takahiko Miyazaki, Masato Takaku, Yuki Ueda, Atsushi Akisawa, The cycle time optimization of a novel dual evaporator type three-bed adsorption chiller, Proceedings of the 5th Asian Conference on Refrigeration and Air-conditioning, A1-040, 2010.06. |
| 130. |
Masakazu Sato, Takahiko Miyazaki, Yuki Ueda, Atsushi Akisawa, Improvement of adsorption heat exchangers by the enhancement of contact points between adsorbent and surface, Proceedings of the 5th Asian Conference on Refrigeration and Air-conditioning, A6-043, 2010.06. |
| 131. |
Takahiko Miyazaki, Atsushi Akisawa, Bidyut Baran Saha, The performance analysis of a novel dual evaporator type three-bed adsorption chiller, International Journal of Refrigeration, 10.1016/j.ijrefrig.2009.10.005, 33, 2, 276–285, 2010.03. |
| 132. |
Marlinda, Aep Saepul Uyun, Takahiko Miyazaki, Yuki Ueda, Atsushi Akisawa, Numerical analysis of double effect adsorption refrigeration cycle using silica-gel/water working pair, 2010 International Symposium on Next- generation Air Conditioning and Refrigeration Technology, P10 1-8, 2010.02. |
| 133. |
Takahiko Miyazaki, Yusaku Motohashi, Yuki Ueda, Atsushi Akisawa, Shinji Shindoh, Masazumi Godo, Takeshi Takatsuka, Study on energy saving air-conditioning system using compact desiccant ventilation units, Part 28: The optimization of the operating conditions of direct heating regeneration type desiccant unit, 2010 International Symposium on Next- generation Air Conditioning and Refrigeration Technology, GS17 1-7, 2010.02. |
| 134. |
A.S. Uyun, A. Akisawa, T. Miyazaki, Y. Ueda, T. Kashiwagi,, Numerical analysis of an advanced three-bed mass recovery adsorption refrigeration cycle, Applied Thermal Engineering, 10.1016/j.applthermaleng.2009.02.008, 29, 14-15, 2876–2884, 2009.10. |
| 135. |
Aep Saepul Uyun, Takahiko Miyazaki, Yuki Ueda, Atsushi Akisawa, High performance cascading adsorption refrigeration cycle with internal heat recovery driven by a low grade heat source temperature, Energies, 10.3390/en20401170, 2, 4, 1170–1191, 2009.10. |
| 136. |
Takahiko Miyazaki, Atsushi Akisawa, The influence of the heat exchanger parameters on the optimum cycle time of adsorption chillers, Applied Thermal Engineering, 10.1016/j.applthermaleng.2009.01.005, 29, 13, 2708–2717, 2009.09. |
| 137. |
T. Miyazaki, A. Akisawa, B.B. Saha, I.I. El-Sharkawy, A. Chakraborty, A new cycle time allocation for enhancing the performance of two-bed adsorption chillers, International Journal of Refrigeration, 10.1016/j.ijrefrig.2008.12.002, 32, 5, 846–853, 2009.08. |
| 138. |
Aep Saepul Uyun, Takahiko Miyazaki, Yuki Ueda, Atsushi Akisawa, Experimental investigation of a three-bed adsorption refrigeration chiller employing an advanced mass recovery cycle, Energies, 10.3390/en20300531, 2, 3, 531–544, 2009.07. |
| 139. |
Yasushi Ishida, Masaaki Bannai, Takahiko Miyazaki, Yasushi Harada, Ryuichi Yokoyama, Atsushi Akisawa, The optimal operation criteria for a gas turbine co- generation system, Energies, 10.3390/en20200202, 2, 2, 202–225, 2009.04. |
| 140. |
A. Akisawa, S. Matsuo, T. Miyazaki, Y. Ueda, T. Kashiwagi, Application of solution transportation absorption heat pump to transfer cooling and heating with single working fluid, International Sorption Heat Pump Conference 2008, AB-105, 2008.09. |
| 141. |
T. Miyazaki, Y. Higashida, I. Nikai, A. Akisawa, T. Kashiwagi, Performance improvement of desiccant air conditioning systems by the recirculation of product air, International Sorption Heat Pump Conference 2008, AB-027, 2008.09. |
| 142. |
T. Miyazaki, A. Akisawa, T. Oda, T. Kashiwagi, Energy saving potential of adsorption chillers in office buildings by cycle time control at part load conditions, International Sorption Heat Pump Conference 2008, AB-028, 2008.09. |
| 143. |
S. S. Elsayed, T. Miyazaki, Y. Hamamoto, A. Akisawa, T. Kashiwagi, Performance analysis of air cycle refrigerator integrated desiccant system for cooling and dehumidifying warehouse, International Journal of Refrigeration, 10.1016/j.ijrefrig.2007.07.002, 31, 2, 189–196, 2008.03. |
| 144. |
Masaaki Bannai, Yasushi Tomita, Yasushi Ishida, Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, Risk hedging against the fuel price fluctuation in energy service business, Energy, 10.1016/j.energy.2007.05.003, 32, 11, 2051–2060, 2007.11. |
| 145. |
Aep Saepul Uyun, Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, Performance comparison of double-effect adsorption refrigeration cycles, Proceedings of the 8th Asian Thermophysical Properties Conference, 103, 2007.08. |
| 146. |
Takahiko Miyazaki, Aep Saepul Uyun, Atsushi Akisawa, Takao Kashiwagi, Comparison of the optimum performances of adsorption heat pump cycles with various adsorbent- adsorbate pairs, Proceedings of the 8th Asian Thermophysical Properties Conference, 085, 2007.08. |
| 147. |
I Gusti Agung Bagus Wirajati, Aep Saepul Uyun, K.C.A. Alam, Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, Experimental study on adsorption chiller with reheat two stage cycle, Proceedings of the 8th Asian Thermophysical Properties Conference, 015, 2007.08. |
| 148. |
Atsuhiro Kawamura, Atsushi Akisawa, Takao Kashiwagi, Takahiko Miyazaki, Possibility of applying biomass energy to Japanese greenhouses for crop production, Renewable Energy 2006 Proceedings, 1103–1106, 2006.10. |
| 149. |
Takahiko Miyazaki, Hiroyoshi Tasai, Atsushi Akisawa, Takao Kashiwagi, Development of a novel concentration photovoltaic generator for buildings with double facades: Design of a nonimaging Fresnel lens solar concentrator for vertical use, Renewable Energy 2006 Proceedings, 282–285, 2006.10. |
| 150. |
Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, The effects of solar chimneys on thermal load mitigation of office buildings under the Japanese climate, Renewable Energy, 10.1016/j.renene.2005.05.003, 31, 7, 987–1010, 2006.06. |
| 151. |
Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, Application of the particle swarm optimization to the design of heating and cooling plants of buildings, Proceedings of the 3rd Asian Conference on Refrigeration and Air-conditioning, I, 209–212, 2006.05. |
| 152. |
Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, Energy savings of office buildings by the use of semi-transparent solar cells for windows, Renewable Energy, 10.1016/j.renene.2004.05.010, 30, 3, 281–304, 2005.03. |
| 153. |
Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, Guohui Gan, A computational fluid dynamics analysis of solar chimneys integrated with photovoltaics, World Renewable Energy Congress VIII,, 2004.09. |
| 154. |
Takahiko Miyazaki, Ralf Leutz, Atsushi Akisawa, Takao Kashiwagi, Energy self-sufficient urban buildings: Evaluation of buildings integrated photovoltaics, World Renewable Energy Congress VII, 2002.07. |
| 155. |
Takahiko Miyazaki, Yong Tae Kang, Atsushi Akisawa, Takao Kashiwagi, A combined power cycle using refuse incinerator and LNG cold energy, Energy, 10.1016/S0360-5442(00)00002-5, 25, 7, 639–655, 2000.07. |
| 156. |
Ralf Leutz, Bidyut B. Saha, Takahiko Miyazaki, Atsushi Akisawa, Takao Kashiwagi, Hiroshi Okano, Ryuji Kuramitsu, Desiccant dehumidification for solar driven absorption air conditioning, World Renewable Energy Congress V, 2122–2125, 1998.09. |
