Kohei Ito | Last modified date:2023.11.22 |
Professor /
Hydrogen Utilization Engineering
Department of Mechanical Engineering
Faculty of Engineering
Department of Mechanical Engineering
Faculty of Engineering
Graduate School
Undergraduate School
Other Organization
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Homepage
https://kyushu-u.elsevierpure.com/en/persons/kohei-ito
Reseacher Profiling Tool Kyushu University Pure
http://www.mech.kyushu-u.ac.jp/~fcsl/index.html
Introduction of Fuel Cell System Laboratory、member、research、photo gallary .
Fax
092-802-0001
Academic Degree
Study on microscopic transport phenomena at solid-solid interface
Country of degree conferring institution (Overseas)
No
Field of Specialization
Electrochemical Systems, Thermal Engineering, Energy Conversion
Total Priod of education and research career in the foreign country
00years00months
Outline Activities
R&D:#To establish the water management for PEMFC, I am developing in-situ measurement and observation technique such as using micro-thermocouples. Based on the measurent result, I am investigating the relationship between performance and the phase of water. #Heat balance and process simulation for highly-efficient stationary SOFC system #I investigate the two phase flow inside the water electrolysis cell with numerical simulation and a visualization cell. Especially, we try to figure out how the bobbles produced impacts the electrolyze performance. Based on these analyses, we challenge to make its performance improve. #Electrochemical pump is now under development, which can work with isothermal process and expects to own a higher efficiency than conventional mechanical compressor # Development of reversible cell as buffer to renewable energy fluctuation#Noble frequency analysis and its appropriation to large scale electrochemical cell. #Fuel cells in space. #Combustion in fuel cell. #Boiling-superimposed Water electrolysis -A challenge to improve conversion efficiency
Education: Thermodynamics, Thermal energy conversion, Thermal energy conversion, hydrogen utilization system, Fuel cell fundamentals. I supervise graduate and undergraduate students.
Education: Thermodynamics, Thermal energy conversion, Thermal energy conversion, hydrogen utilization system, Fuel cell fundamentals. I supervise graduate and undergraduate students.
Research
Research Interests
Membership in Academic Society
- Improving PEM water electrolyzer performance by superimposing boiling
keyword : non-equilibrium, reducing electrolysis voltage, gas/liquid two phase
2016.12~2026.03Hydrogen solubility for water under high pressure condition. - Investigation on limitation and degradation of PEMEC for highly utilizing renewable energy
keyword : limiting current density, fractured power supply
2016.12~2023.03Hydrogen solubility for water under high pressure condition. - Combustion in Fuel Cell -Mechanism on abrupt evolution from moderate combustion to combustion damage-
keyword : Combustion
2016.04~2023.03Hydrogen solubility for water under high pressure condition. - Challenging to reduce electrolysis voltage by superimposing boiling on PEMWE electrochemical reaction
keyword : Thermodynamic Coupling
2015.12~2023.03Hydrogen solubility for water under high pressure condition. - Fundamental researches for developing middle scale of SOFC system
keyword : re-circulation, carbon deposition, DRT, sealing
2013.12~2019.03Hydrogen solubility for water under high pressure condition. - Management of fuel cell under vacuum condition
keyword : convection, liquid cooling, Gas leakage, Crossover
2015.04~2019.03Hydrogen solubility for water under high pressure condition. - Numerical analysis on SOFC system for improvement of its performance.
keyword : re-circulation, carbon deposition
2013.12~2019.03Hydrogen solubility for water under high pressure condition. - Optimization of high temperature PEM water electrolyzer
keyword : High temperature, Polymer Electrolyte Membrane
2013.12~2016.03Hydrogen solubility for water under high pressure condition. - Experimental and thermodynamic analysis on the phase state of electrochemically produced water
keyword : equilibrium
2011.04~2016.03Hydrogen solubility for water under high pressure condition. - Experimental exploration of critical mass transport at triple phase boundary in high-pressure water electrolysis
keyword : Visualization, bubble, High pressure, PEM, water electrolyzer
2011.12~2016.03Hydrogen solubility for water under high pressure condition. - Mechanism in the degree of super cool in Polymer Electrolyte Fuel Cell
keyword : hydrophilic, hydrophobic, pore diameter
2011.04~2013.03Hydrogen solubility for water under high pressure condition. - Experimental analysis of electrochemical hydrogen pump
keyword : polymer electrolyte membrane, cross leak
2009.09~2013.03Hydrogen solubility for water under high pressure condition. - Expermental analysis of hydrogen solubility in water and electrolyte under high pressure condition
keyword : solubility, hydrogen, phase equilibrium
2006.04~2011.03Hydrogen solubility for water under high pressure condition. - In-situ measurement of hydrogen solubility and diffusivity in polymer material by NMR spectroscopy
keyword : solubility, polymer, rubber
2008.04~2012.03Measurement of hydrogen solubility for polymer material. - New measurement technique with optical fiber
keyword : optical fiber, measurement, inside
2009.04~2011.03. - Development of measurement method for PEFC in through-plane direction
keyword : Temperature, water droplet, visualization cell
2006.04~2011.03Development of in-situ measurement technique for fuel cell. - Development a novel thermoelectric component
keyword : thermoelectric voltage, nano-structure
2007.12~2011.03Development of a new thermo-electric device.. - Solubility measurement of hydrogen gas in polymer with NMR spectroscopy
keyword : solubility, polymer
2008.04~2012.03Measurement of hydrogen solubility for polymer material. - Measurement and analysis for Hydrogen gas solubility in water under high pressure condition
keyword : solubility, database, hydrogen gas, phase equilibrium
2006.04~2010.03Hydrogen solubility for water under high pressure condition. - Experimental analysis for the impact of gas-liquid two phase flow on water electrolyzer
keyword : bubble, differential pressure, visualization
2005.04~2009.03We analize the effect of two phase flow to the performance of water electrolysis cell.. - Experimental analysis for water transport in polymer membrane with NMR method
keyword : water, NMR, diffusivity
2004.04~2008.03We succeeded in visualizing the water molecule hehavior in polymer electrolyte memblane with NMR method. Based on this visulization technich, we develop new sensor of water molecule for PEMFC.. - Numerical simulation of heat and electic transport in meso-scale domain
keyword : Bolzman transport equation, electron, thermoelectric voltage, mean free path
2004.04~2008.03We developed new numerical simulation code for electron transport, which is based on Boltzmann transport equation. This code make possible to silmulate the performance of electronic devices , whose representative size is mean free path.. - Study on heat and flow behavior in high-pressure water electrolysis cell
keyword : high pressure, water electrolyzer, efficiecy
2004.04~2008.03We developed new simulator for High-pressure Water Electrolysis cell considering hydrogen solubility. With this simulator, we predicted the thermal and flow characteristics, such as temperature distribution. This result help the electrolysis cell to operate.. - Water management for PEMFC
keyword : flooding, drying, cell voltage
2003.07~2011.03We succeeded in visulizing the water droplet in diffusion layer of PEMFC, with novel transparent cell. Comparing with this visulization result, we evalute the two-phase flow simulation for PEMFC.. - Characterization of SOFC and its combined system by numerical simulation
keyword : SOFC, combined system, solar energy
1996.04~2003.03We numerically simulated SOFC-GT combined cycle, and evaluted its system performance.. - Investigation of heat behavior in secandary battery
keyword : Lithium ion, Overvoltage, charge, discharge
1996.04~2003.03We numerically simulated the thermal behavior for Li-ion secondary battery considering exothermic factor, such as overvolatege and entropy change. This simulation well-predicts the temperature change during charging operation of the cell.. - Characterization of polymer electrolyte cell: water electrolyer, dehumidifier and ozonizer
keyword : water electrolyzer, ozon, dehumidification
1996.04~2003.03We experimentally evaluted the performance desicacator, which consists of reverse cycle of PEMFC. In this test, we found out the effects of operation parameter, such as cell temperature, on its performance.. - Study on PEMFC
keyword : cell temperature, load current, relative humidity, transient characteristics
1996.04~2003.03We experimentally evalute the steady and transient state performance of PEMFC, with systematically changing operation parameter. We succeeded in extracting the representative time, which determine the transient characteristic.. - Experimental and numerical analysis for discharge deNOx process
keyword : discharge plazma, NOx, energy distribution function, mass spectrometry
1996.04~2003.03Using mass appearance spectroscopy we measured the radicals in deNOx proccess, where simulated exhoust gas is irradiated by repetitive pulsed discharge. In additon we numerically solved the this process with reation rate equations and Boltzmann transport equation for electron energy distribution. Due to this investigation, we found out the effect of radicals, such as OH, on deNOx performance.. - Investigation on thermal and electric transport at point contact
keyword : nano, point contact, thermoelectric voltage, tunneling effect
1993.04~1996.03We measured the heat and electron transport through microscopic contact, whose diameter is 10nm. As result, we found out that thermo-electromotive force appeard even when the all consititutive materival for this contact was same, and that this phenomena can be explained by non-equilibrium effect.. - Measurement of thermal boundary resistance between high-Tc superconductive thin film and substrate
keyword : thermal boundary resistance, bolometer
1991.04~1993.04We succeeded in measuring the thermal boundary resistance between high-Tc superconductive thin film and its subtrate, with two-strip method..
- High-pressure water electrolysis has the potential to directly and efficiently produce high-pressure hydrogen gas from water at normal pressure. However, some amount of hydrogen gas produced at cathode permeates to anode because of the large pressure difference between them, and this permeation reduces the efficiency. This study challenges to decrease the permeation. Incorporable countermeasures from the system engineering point of view, namely convection, wettability and buoyancy effect will be here evaluated and optimized, leading to extreme enhancement of the departure of hydrogen gas from the triple phase bondary, and leading to the critical performance of high-pressure water electrolyzer.
- This project test the novel water electrolisys cell, which can produce 35MPa hydrogen gas without compresser. In this test, I analyze the thermal and flow characteristics of this cell, and evalute especially the thermal problem when the cell enlarge.
- ‘Development of PEMFC simulator considering two phase flow’ Until now, there are several PEMFC simulator considering two phase flow. As a task of PEMFC simulator hereafter, it must support to capture the unsteady phenomena of flooding and drying, which are appeared during cell operation. In addition, the reliability of simulator must be verified rigorously with comparison between simulator and practical cell operation. In this sub-project, we added the energy conservation equation to our PEMFC simulator developed in previous year, and modified it to simulate unsteady state, and then we aimed to obtain the agreement within 10% between simulator and measured value. As result, the simulator showed more practical two-phase flow phenomena, such as distribution of liquid water in GDL. For the unsteady simulation where the load current changes step-wisely, we succeed to obtain transient response of cell voltage which seems to be appeared in practical operation, and we understood it qualitatively with representative times related on the phenomena in cell. In addition, we succeeded to show the relationship between over-voltage and saturation ratio which show the occupation ratio of liquid water to a unit volume. The IV characteristics of simulation agreed with the measured values within 10%. ‘Visualization of flooding in GDL using microscope’ Until now the flooding in GDL, which is important for water management, has not been understood, because GDL is made of opaque material having micro-porous structure and thus it is difficult to apply typical method to measure or visualize the flooding in GDL. Against this background, we executed this sub-subject aiming to visualize the liquid water droplet in GDL, and to obtain where the water droplet is distributed. At first, we designed and made a novel cell, which can enable us to visualize the cross section of GDL. We operated this cell and observed the cross section with digital microscope. As result, we succeed to capture water droplets, which are thought to be caused by cathode reaction. The water droplets were produced at the interface between GDL and catalysis layer, and it spread within GDL under the rib. This success of in-situ capturing the water droplet in GDL is worth on the point to take measure against flooding. Moreover, we made and operated a simple interdigitated cell which has only one path through GDL, and measured the differential pressure at cathode flow channel between inlet and outlet. Assuming that the flow in GDL is Darcy flow, we estimated the saturation ratio in GDL from the differential pressure. With this method using interdigitated cell, we figure out the relationship between saturation and operation parameter such as load current, gas utilization.
- This project investigated the thermal problem and related technical issue under micro-machine.
- This project evalute the high temperature steam electrolisys cell, which use solar light as its heat and electric source.
Books
1. | Kohei Ito, Recent Trend in Fuel Cell Science & Technology, Edited by S. Basu, Chapter 5, Water Problem in PEMFC, Springer, (2006), 2006.11. |
Reports
Papers
Presentations
- Electrochemical Society of Japan
- Heat Transfer Society of Japan
- Japan Society of Mechanical Engineering
- Encouraging prize by W.J. Yang
Educational
Educational Activities
I am charge of the classes in undergraduate course of mechanical engineering such as, thermodynamics, thermal energy conversion. In addition, I educate systems and elements issues of hydrogen energy technology, such as fuel cell, through the lecture of hydrogen utilization system etc. I am assigned as supervisor for bachelor, master, and doctor course students.
Other Educational Activities
- 2022.05, I educate safety issues to students and staffs. In addition, practical training are imposed to them, to get understandings of hydrogen gas properties and piping..
- 2014.05, I educate safety issues to students and staffs. In addition, practical training are imposed to them, to get understandings of hydrogen gas properties and piping..
- 2010.07.
- 2009.04.
- 2008.08.
- 2004.05, "Manual of emergency in hydrogen experimental stand".
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