Planar membrane humidifier for fuel cell application: Numerical and experimental case study

•A model for planar membrane humidifier is developed and validated.•Experimental and simulation study of water-to-gas membrane humidifier is presented.•Results show developed model predicts the empirical data with error of less than 7%.•Key role of membrane humidifier is clarified by applying this system for 10 kW stack. One of the basic requirements for proper functioning and managing the water content of the fuel cell is the humidity of the reactant gas. In this paper, a model is developed for investigating the humidification of reactant gas using a water-to-gas planar membrane humidifier. All the governing equations of the model in one-dimensional mode (along the channel length) are solved using an in-house developed code. Then, to validate the model, a humidification single cell is fabricated and the performance of membrane humidifier is investigated both experimentally and numerically. Simulation results show that developed model predicts well the experimental results with an error of less than 7%. The results show that by increasing the length of the channel, the gas temperature increases up to the temperature of heating water, moreover, the relative humidity of the gas would also increase. At high flow rates, the amount of consumed water increases, however, the relative humidity of the gas flow will decrease by about 40% because of the decreased residence time. Finally, the pivotal roles of membrane humidifier in the fuel cell stack is clarified based on the results of applying this system for a 10 kW fuel cell stack.