Shutdown and storage method for fuel cell system at below freezing temperatures
AssigneesDaimler AG, Ford Motor Company, Nissan Motor Co., Ltd.
InventorsMichael Procter, Yosuke Fukuyama, Richard Fellows, Takeshi Shiomi
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Abstract
Improved methods are disclosed for shutting down and storing a fuel cell system, particularly for below freezing temperature conditions. The methods comprise stopping power production from the fuel cell stack, monitoring its temperature, and repeatedly performing a predetermined warming operation if the stack temperature falls to a normal threshold temperature. In the improved methods, either an initial threshold temperature and/or an initial warming operation are used that differ from the respective normal threshold temperature and the predetermined warming operation.
Claims15
A method for shutting down and storing a fuel cell system, the fuel cell system comprising a fuel cell stack that is producing power and an energy supply for heating the fuel cell stack, the method comprising:
- stopping power production from the fuel cell stack;
- monitoring the temperature of the fuel cell stack;
- performing an initial warming operation if the stack temperature falls to an initial threshold temperature;
- and
- repeatedly performing the following steps:
- monitoring the temperature of the fuel cell stack;
- and
- performing a predetermined warming operation if the stack temperature falls to a normal threshold temperature;
- characterized in that at least one of the initial threshold temperature and the initial warming operation differs from the respective normal threshold temperature and the predetermined warming operation.
Dependencies are inferred from the claim text.