The Experts below are selected from a list of 43020 Experts worldwide ranked by ideXlab platform
Kui Jiao - One of the best experts on this subject based on the ideXlab platform.
-
catalytic Hydrogen Oxygen Reaction in anode and cathode for cold start of proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2015Co-Authors: Yueqi Luo, Kui Jiao, Bin Jia, Qing Du, Yan Yin, Huizhi Wang, Jin XuanAbstract:Abstract Fuel cell vehicles (FCVs) have shown the potential of commercialization in recent years. The concerns on the startup ability of proton exchange membrane (PEM) fuel cell stack from subfreezing temperature have risen. The Hydrogen–Oxygen catalytic Reactions assisted cold start method is developed and analyzed in this study. It utilizes a small amount of Hydrogen/air mixture to react at low temperature in the catalyst layers (CLs) through platinum catalyst. The interactions between this assisted method and various startup modes are the major issue to be discussed. Anode catalytic Reaction with air mole fraction higher than 16% is effective to assist a 30-cell stack starting from −25 °C within 13 s in maximum power mode. However, cathode catalytic Reaction cannot sustain a successful startup. The anode humidification effect plays an important role to reduce the stack resistance, and to increase the inherent heat generation rate. In maximum power mode and high current density constant power mode, anode catalytic Reaction assisted cold start can be achieved within 10–20 s from −40 °C. Anode air mole fraction must be higher than 18% to ensure the successful cold start in these two modes. For constant power mode, the operating power must be lower than 12 W per cell. In constant current mode, when the current density is low, there would be less demand for anode catalytic Reaction to achieve successful startup from −40 °C, indicating that lower current density operations have better survivability in low temperature. Nevertheless, much longer start duration is required for lower operating current. Generally, high current density operating mode with high air mole fraction is a more practical and energy efficient cold start strategy, as the startup time can be reduced significantly. Cold start from about −20 °C without ice accumulation is feasible using this method, which may have reduced concern about degradation. Increasing the volume of CL (porosity and thickness) also helps reduce the ice formation.
-
modeling of assisted cold start processes with anode catalytic Hydrogen Oxygen Reaction in proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2013Co-Authors: Qian Guo, Yueqi Luo, Kui JiaoAbstract:Abstract Catalytic Hydrogen–Oxygen Reaction is a potentially effective way to help start up proton exchange membrane fuel cells (PEMFCs) from sub-zero temperatures. In this study, the anode Hydrogen–Oxygen catalytic Reaction is implemented in a three-dimensional multiphase cold start model. It is found that successful cold start from −20 °C can be achieved with the assist of the catalytic Reaction in galvanostatic mode. With anode catalytic Reaction, the start-up current density must be moderate, because a high current density lowers the assisted heating effect, and a low current density slows down the start-up process. The temperature difference between the anode and cathode catalyst layers (CLs) is negligible, which indicates that the heating location in the electrodes for the catalytic Reaction makes no significant difference. The humidification of anode due to the catalytic Reaction also reduces the ohmic resistance of the membrane, leading to enhanced performance during the start-up processes.
Zhigang Shao - One of the best experts on this subject based on the ideXlab platform.
-
investigation on the temperature uniformity and efficiency of cold start up for proton exchange membrane fuel cell stack based on catalytic Hydrogen Oxygen method
Journal of Power Sources, 2021Co-Authors: Shucheng Sun, Jiaqi Sun, Xiaokang Yang, Zhigang ShaoAbstract:Abstract The catalytic Hydrogen/Oxygen Reaction method is one of the primary ways to realize the rapid cold start of proton exchange membrane fuel cell (PEMFC). In this study, the start-up capacity of the catalytic Hydrogen/Oxygen Reaction method is systematically investigated. A tremendous nonuniformity of temperature distribution is found under the condition of one-way mixture gas supply. A reverse feeding unit (RFU) is invented to realize a double-way gas supply to solve this problem. With the aid of RFU, the temperature uniformity during cold start is greatly improved. When the flow rate is 30 L min−1 and air fraction is 24%, the average and the lowest temperature take 55 s and 79 s respectively to rise from −32 °C to 0 °C, and the maximum temperature variance is 12.6. However, the lowest temperature of stack only arrives at −11.8 °C in 79 s when one-way mixture gas is supplied, and the temperature variance evidently increase to 21.4. After the preheating period, the output performance using RFU is 6.01% higher than the one-way gas supply method when the loading current is 250 mA cm−2. The temperature uniformity and power output is improved remarkably by the RFU.
-
catalytic Hydrogen Oxygen Reaction assisted the proton exchange membrane fuel cell pemfc startup at subzero temperature
Journal of Power Sources, 2008Co-Authors: Shucheng Sun, Junbo Hou, Pingwen Ming, Hongmei Yu, Zhigang Shao, Baolian Yi, Zhongjun HouAbstract:Fuel cells for automobile application need to operate in a wide temperature range including freezing temperature. However, the rapid startup of a proton exchange membrane fuel cell (PEMFC) at subfreezing temperature, e.g., -20 degrees C, is very difficult. A cold-start procedure was developed, which made Hydrogen and Oxygen react to heat the fuel cell considering that the FC flow channel was the characteristic of microchannel reactor. The effect of Hydrogen and Oxygen Reaction on fuel cell performance at ambient temperature was also investigated. The electrochemical characterizations such as I-V plot and cyclic voltammetry (CV) were performed. The heat generated rate for either the single cell or the stack was calculated. The results showed that the heat generated rate was proportional to the gas flow rate when H-2 concentration and the active area were constant. The fuel cell temperature rose rapidly and steadily by controlling gas flow rate. (c) 2007 Elsevier B.V. All rights reserved.
Yueqi Luo - One of the best experts on this subject based on the ideXlab platform.
-
catalytic Hydrogen Oxygen Reaction in anode and cathode for cold start of proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2015Co-Authors: Yueqi Luo, Kui Jiao, Bin Jia, Qing Du, Yan Yin, Huizhi Wang, Jin XuanAbstract:Abstract Fuel cell vehicles (FCVs) have shown the potential of commercialization in recent years. The concerns on the startup ability of proton exchange membrane (PEM) fuel cell stack from subfreezing temperature have risen. The Hydrogen–Oxygen catalytic Reactions assisted cold start method is developed and analyzed in this study. It utilizes a small amount of Hydrogen/air mixture to react at low temperature in the catalyst layers (CLs) through platinum catalyst. The interactions between this assisted method and various startup modes are the major issue to be discussed. Anode catalytic Reaction with air mole fraction higher than 16% is effective to assist a 30-cell stack starting from −25 °C within 13 s in maximum power mode. However, cathode catalytic Reaction cannot sustain a successful startup. The anode humidification effect plays an important role to reduce the stack resistance, and to increase the inherent heat generation rate. In maximum power mode and high current density constant power mode, anode catalytic Reaction assisted cold start can be achieved within 10–20 s from −40 °C. Anode air mole fraction must be higher than 18% to ensure the successful cold start in these two modes. For constant power mode, the operating power must be lower than 12 W per cell. In constant current mode, when the current density is low, there would be less demand for anode catalytic Reaction to achieve successful startup from −40 °C, indicating that lower current density operations have better survivability in low temperature. Nevertheless, much longer start duration is required for lower operating current. Generally, high current density operating mode with high air mole fraction is a more practical and energy efficient cold start strategy, as the startup time can be reduced significantly. Cold start from about −20 °C without ice accumulation is feasible using this method, which may have reduced concern about degradation. Increasing the volume of CL (porosity and thickness) also helps reduce the ice formation.
-
modeling of assisted cold start processes with anode catalytic Hydrogen Oxygen Reaction in proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2013Co-Authors: Qian Guo, Yueqi Luo, Kui JiaoAbstract:Abstract Catalytic Hydrogen–Oxygen Reaction is a potentially effective way to help start up proton exchange membrane fuel cells (PEMFCs) from sub-zero temperatures. In this study, the anode Hydrogen–Oxygen catalytic Reaction is implemented in a three-dimensional multiphase cold start model. It is found that successful cold start from −20 °C can be achieved with the assist of the catalytic Reaction in galvanostatic mode. With anode catalytic Reaction, the start-up current density must be moderate, because a high current density lowers the assisted heating effect, and a low current density slows down the start-up process. The temperature difference between the anode and cathode catalyst layers (CLs) is negligible, which indicates that the heating location in the electrodes for the catalytic Reaction makes no significant difference. The humidification of anode due to the catalytic Reaction also reduces the ohmic resistance of the membrane, leading to enhanced performance during the start-up processes.
Shucheng Sun - One of the best experts on this subject based on the ideXlab platform.
-
investigation on the temperature uniformity and efficiency of cold start up for proton exchange membrane fuel cell stack based on catalytic Hydrogen Oxygen method
Journal of Power Sources, 2021Co-Authors: Shucheng Sun, Jiaqi Sun, Xiaokang Yang, Zhigang ShaoAbstract:Abstract The catalytic Hydrogen/Oxygen Reaction method is one of the primary ways to realize the rapid cold start of proton exchange membrane fuel cell (PEMFC). In this study, the start-up capacity of the catalytic Hydrogen/Oxygen Reaction method is systematically investigated. A tremendous nonuniformity of temperature distribution is found under the condition of one-way mixture gas supply. A reverse feeding unit (RFU) is invented to realize a double-way gas supply to solve this problem. With the aid of RFU, the temperature uniformity during cold start is greatly improved. When the flow rate is 30 L min−1 and air fraction is 24%, the average and the lowest temperature take 55 s and 79 s respectively to rise from −32 °C to 0 °C, and the maximum temperature variance is 12.6. However, the lowest temperature of stack only arrives at −11.8 °C in 79 s when one-way mixture gas is supplied, and the temperature variance evidently increase to 21.4. After the preheating period, the output performance using RFU is 6.01% higher than the one-way gas supply method when the loading current is 250 mA cm−2. The temperature uniformity and power output is improved remarkably by the RFU.
-
catalytic Hydrogen Oxygen Reaction assisted the proton exchange membrane fuel cell pemfc startup at subzero temperature
Journal of Power Sources, 2008Co-Authors: Shucheng Sun, Junbo Hou, Pingwen Ming, Hongmei Yu, Zhigang Shao, Baolian Yi, Zhongjun HouAbstract:Fuel cells for automobile application need to operate in a wide temperature range including freezing temperature. However, the rapid startup of a proton exchange membrane fuel cell (PEMFC) at subfreezing temperature, e.g., -20 degrees C, is very difficult. A cold-start procedure was developed, which made Hydrogen and Oxygen react to heat the fuel cell considering that the FC flow channel was the characteristic of microchannel reactor. The effect of Hydrogen and Oxygen Reaction on fuel cell performance at ambient temperature was also investigated. The electrochemical characterizations such as I-V plot and cyclic voltammetry (CV) were performed. The heat generated rate for either the single cell or the stack was calculated. The results showed that the heat generated rate was proportional to the gas flow rate when H-2 concentration and the active area were constant. The fuel cell temperature rose rapidly and steadily by controlling gas flow rate. (c) 2007 Elsevier B.V. All rights reserved.
Jin Xuan - One of the best experts on this subject based on the ideXlab platform.
-
catalytic Hydrogen Oxygen Reaction in anode and cathode for cold start of proton exchange membrane fuel cell
International Journal of Hydrogen Energy, 2015Co-Authors: Yueqi Luo, Kui Jiao, Bin Jia, Qing Du, Yan Yin, Huizhi Wang, Jin XuanAbstract:Abstract Fuel cell vehicles (FCVs) have shown the potential of commercialization in recent years. The concerns on the startup ability of proton exchange membrane (PEM) fuel cell stack from subfreezing temperature have risen. The Hydrogen–Oxygen catalytic Reactions assisted cold start method is developed and analyzed in this study. It utilizes a small amount of Hydrogen/air mixture to react at low temperature in the catalyst layers (CLs) through platinum catalyst. The interactions between this assisted method and various startup modes are the major issue to be discussed. Anode catalytic Reaction with air mole fraction higher than 16% is effective to assist a 30-cell stack starting from −25 °C within 13 s in maximum power mode. However, cathode catalytic Reaction cannot sustain a successful startup. The anode humidification effect plays an important role to reduce the stack resistance, and to increase the inherent heat generation rate. In maximum power mode and high current density constant power mode, anode catalytic Reaction assisted cold start can be achieved within 10–20 s from −40 °C. Anode air mole fraction must be higher than 18% to ensure the successful cold start in these two modes. For constant power mode, the operating power must be lower than 12 W per cell. In constant current mode, when the current density is low, there would be less demand for anode catalytic Reaction to achieve successful startup from −40 °C, indicating that lower current density operations have better survivability in low temperature. Nevertheless, much longer start duration is required for lower operating current. Generally, high current density operating mode with high air mole fraction is a more practical and energy efficient cold start strategy, as the startup time can be reduced significantly. Cold start from about −20 °C without ice accumulation is feasible using this method, which may have reduced concern about degradation. Increasing the volume of CL (porosity and thickness) also helps reduce the ice formation.
