Limit Operating Temperature in Polymer Electrolyte Membrane Fuel Cells

Abstract

In this research, a control technique for polymer electrolyte membrane (PEM) fuel cells based on the limit operating temperature is introduced. The limit operating temperature is the highest temperature in which the PEM fuel cell can operate, preserving a recommended relative humidity and air stoichiometry. The operating temperature influences the fuel cell voltage; the higher the temperature, the better the voltage. A PEM fuel cell model is applied to analyze the evolution and dependence among the variables. The tests were performed considering two situations: PEM fuel cells without extra humidification and PEM fuel cells with an external humidifier. Also, the influence of humidity and temperature of the input air can be analyzed separately. The results show that the limit temperature strategy is stable and consistent under different operational conditions such as different load requirements and presence/absence of extra humidification.

Membrane degradation in PEM water electrolyzer: Numerical modeling and experimental evidence of the influence of temperature and current density

“…Degradation models for PEMFC can be found in the literature focusing on different mechanisms such as catalysts and catalyst layers degradation [12], cathode catalyst support corrosion [13], membrane degradation [14,15] and limit temperature [16]. However, the PEMFC is not the exact opposite of an electrolysis cell.…”

Experimental study on the start-up with dry gases from normal cell temperatures in self-humidified proton exchange membrane fuel cells

“…However, as the cell temperature rises, the corresponding saturation pressure also goes up. If the cell temperature is overheated, the membrane gets dehydrated and it makes limited fuel cell reaction [6,11]. For this reason, as shown in Fig.…”

Dimensionamento De Um Umidificador Para Células a Combustível De Membrana Protônica Em Aplicações Móveis

“…A energia necessária para iniciar a reação é chamada de energia de ativação, sendo que, em algumas reações, pode atrasar o processo. As perdas por ativação (V act ) ocorrem quando a densidade de corrente na célula é baixa [9].…”

“…Pela Equação (14) pode-se calcular J [6] [9]. J = J OUT + J n (14) Onde J OUT : densidade corrente elétrica de saída da célula (A/cm 2 ); J n : representa a passagem de combustível e perda de corrente interna da célula (A/cm 2 ).…”

“…A Figura 5 mostra a evolução da tensão em função do tempo. A variação de calor gerado na PEMFC é calculada pela Equação (19) [9].…”