Fuel cell system and shutdown purging method thereof

Abstract

The invention relates to a fuel cell system and a shutdown purging method thereof. The system comprises a galvanic pile, an air supply subsystem connected with a cathode of the galvanic pile, a hydrogen supply subsystem connected with an anode of the galvanic pile, a cooling circulation subsystem connected with the galvanic pile, a hydrogen / air mixing box respectively connected with the air supply subsystem and the hydrogen supply subsystem and a controller used for controlling the subsystems. The output end of the galvanic pile is connected with the driving motor by being connected with the DC / DC converter, and after the controller receives a shutdown command, in the fuel cell system shutdown process, the controller controls the temperature of the galvanic pile according to the cooling circulation subsystem and controls the actuator to correspondingly purge the interior of the galvanic pile. The method has the advantages of improving the cold start capability of the fuel cell galvanic pile at low temperature, effectively prolonging the service life of the fuel cell galvanic pile and the like.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a fuel cell system and a shutdown purging method thereof. Background technique [0002] A proton exchange membrane fuel cell is a power generation device that directly converts the chemical energy of fuel (such as hydrogen) into electrical energy. When continuously supplied with fuel and oxidant, the fuel cell can continuously output electricity and heat. It has the advantages of high power generation efficiency, low noise, fast dynamic response, and zero emissions. It is also considered to be one of the cleanest and most efficient new energy power generation devices and can be widely used in automotive power systems. [0003] The electrochemical reaction of the proton exchange membrane fuel cell generates electricity, heat and water. After the operation at room temperature, the inside of the fuel cell should be purged accordingly to discharge the excess residual water and im...

AI Technical Summary

Problems solved by technology

The conventional purging method is to use high-purity nitrogen for purging after shutdown. This method affects the low-temperature start-up ability of the fuel cell, and will participate in moisture and impurities inside the stack, thereby affecting the life of the fuel cell.

At present, various methods are used to shut down and purge the fuel cell. For example, Chinese patent CN 103915642A uses a nitrogen generator to purify N2 from the air. Purge to protect the stack after shutting down, but for the vehicle fuel cell system, the volume is relatively complicated and the space layout is difficult, which is not conducive to practical use

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