Fuel cell stack heat dissipation from

Figures 10.16 and 10.17 show the simulated temperature distribution in the electrolyte for the three-cell and ten-cell stack models, respectively. For the three-cell and ten-cell stack models, the flow rates of air and fuel are three times and ten times those for the single-cell stack model, respectively. The other calculation conditions are the same as those employed in the single-cell stack model. In Figure 10.16, the upper and lower diagrams correspond to the upper and the middle cells in the threecell stack, respectively. It can be observed that the maximum temperature is higher in the middle cell than in the upper cell. This is because the generated heat in the middle cell dissipates indirectly to outside the cell stack through the upper and lower cells. This indirect dissipation of the generated heat from the middle cell to the outside cell is smaller in the ten-cell stack, and as a result, the generated heat remains in the middle cell. Accordingly, the temperature in the middle cell in the ten-cell stack...

Part of the coolant loop has two separate paths one path does not go through the heat exchanger and is used from the startup of the fuel cell system until the coolant temperature increases to a preset value (e.g., 60°C) to accelerate the rise of the coolant temperature the other path goes through the heat exchanger and is used when the coolant temperature reaches the preset value. Based on the stack needs, the coolant flow rate is adjusted by the coolant pump, and the heat that is dissipated out of the system enclosure is controlled by the fan mounted on the heat exchanger. 

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