Hydrogen preheating in a PEMFC system employing a heat exchanger equipped with an innovative turbulator

Abstract

Membrane electrodes are the essential parts of a proton exchange membrane fuel cell (PMFC), and they have a significant impact on the shelf life of the stack. Under the influence of prolonged low-temperature conditions, the gas diffusion layer will not be able to remove liquid water and gas transport because of the ruined micro-porous structure. Therefore, hydrogen preheating of the PEMFC anode side is critical. In the present work, a new type of heat exchanger as hydrogen preheater is presented in which an innovative turbulator is inserted at the entrance of the hydrogen side. The proposed turbulator consists of two sections; (i) the finned part with spiral blades, and (ii) the conical part with lateral outputs. A commercial CFD code has been employed to perform a series of numerical simulations based on finite volume method. The impacts of four efficient geometrical parameters on the hydrothermal behavior of hydrogen inside the proposed preheater are investigated numerically. The considered geometrical parameters are the number of the blades, turbulator's length, turbulator's diameter, and blade's angle. All simulations have been performed in any case for four various Reynolds numbers, including Re = 40,000, 60,000, 80,000, and 100,000. The obtained numerical outcomes depicted that employing the proposed hydrogen preheater of PEMFC leads to better performance of the PEMFC by increasing the durability of membrane electrodes.