Author: Yoora Choi (Chungnam National University) - Proton Exchange Membrane Fuel Cell (PEMFC) is gaining attention as a power source suitable for mobile energy systems based on its high power density and low-temperature operation characteristics, and its applicability in various transportation fields is expanding. Recently, technological approaches for the application of PEMFC systems have been actively developed in various commercial mobility fields such as railways, ships, and aviation. In particular, high-output hydrogen fuel cell systems are attracting attention as a promising power source in the HDV (Heavy-Duty Vehicle) field that requires long-distance operation. Since HDVs operate under continuously high output conditions during operation, the amount of heat generated in the fuel cell stack increases, requiring stable heat control. In addition, HDVs often have low driving speeds due to their structural characteristics, so the natural cooling effect through the inflow of outside air during operation is limited, and the operating ratio of the cooling system auxiliary device may increase, which may increase parasitic power consumption within the system. Since the polymer membrane of PEMFC can deteriorate when the temperature rises, leading to a decrease in performance, maintaining the stack temperature and securing cooling performance are key factors for securing system reliability. This study analyzed the heat dissipation characteristics and power demand according to the operating conditions of the thermal management system based on the HDV model equipped with two PEMFCs. To this end, a fuel cell stack dynamic characteristic model was constructed in the MATLAB/SIMULINK® environment, and a cooling system consisting of a water pump, radiator, three-way valve, and reservoir was integrated. Through simulation, the stack heat generation and heat release characteristics of the cooling system were compared, and the changes in system efficiency were evaluated according to the coolant and stack temperatures.
