Numerical simulation of gas–heat–water distribution characteristics of Ammonia–Hydrogen fuel cell

Improving the operating conditions can enhance the output performance of PEMFCs based on Ammonia decomposition gas as fuel (Ammonia–Hydrogen fuel cell). Therefore, in this study, a 3-dimensional non-isothermal numerical model was established to study the gas–heat–water distribution of Ammonia–Hydrogen fuel cell under different operating conditions, and the performance improved by operating conditions is analyzed through regional quantification, and then optimize the operating conditions for improving performance. The research results show that increasing the working pressure, gas humidity and nitrogen adsorption can improve the output performance of the fuel cell effectively. Under low-pressure operating conditions, increasing the unit pressure can increases the output performance by 80%; under low-humidity operating conditions, increasing the relative humidity by 0.15 can increases the output performance by 8%; under low-hydrogen content operating conditions, increasing the mole fraction of hydrogen by 5% through nitrogen adsorption can increases the output performance by 10%. Along the flow direction, the molar concentration distribution characteristics of reactant gas is opposite to the change trend of membrane water content, which is closely related to the reaction rate; the overall change trend of heat is consistent with the water content of the membrane, but the hot spot value at the outlet has a downward trend with the strengthening of the reaction conditions and the continuous increase of the load. When operating conditions changes, the variation trend of the regional total output is different, and the maximum value of the total output varies from the operating conditions. Optimizing the operating conditions can make it possible to achieve the output performance based on pure hydrogen as fuel.