Low-temperature cold start method of fuel cell

Abstract

A low-temperature cold start method of a fuel cell is used for preventing the water generated during the work of the fuel cell from freezing during low-temperature cold start, and comprises the steps of dividing a low-temperature cold start process into a start preparation process, a low-temperature activation process and a temperature rise start process. According to the present invention, in the low-temperature activation process, a fuel cell stack starts to operate under the condition that a water pump does not operate, and the fuel cell stack is activated, so that the adverse consequence that the temperature of the fuel cell stack is too low due to heat exchange with a cooling water circulation loop under the condition that the temperature of the fuel cell stack does not rise to a sufficient temperature, and finally the fuel cell stack is unsuccessfully started, is avoided; after the low-temperature activation process is ended, the speed of the water pump is gradually controlled, so that the fuel cell stack still has the stable power output capability at low temperature even if the fuel cell stack exchanges heat with the cooling water circulation loop in the subsequent temperature rise starting process, the the low-temperature cold start can be completed while the output power is stabilized in the heating start process, the energy-saving effect is good, and the heating performance is stable.

Description

technical field [0001] The invention relates to the technical field of automobile fuel cells, in particular to a low-temperature cold start method for fuel cells. Background technique [0002] Among the fuel cells, the proton exchange membrane fuel cell is recognized as an electric vehicle due to its high proton conductivity and stability at low temperature, low operating temperature, fast start-up, high specific power, simple structure and convenient operation. It is the preferred energy source for fixed power stations, etc., and has become the mainstream battery for fuel cell vehicles. However, when starting in a low-temperature environment, since the water on the proton exchange membrane will freeze, the water generated after the reaction on the cathode side will also remain inside the stack, and it will freeze when it is below the freezing point. The ice phenomenon will cause the volume of the proton exchange membrane to expand, and the heat generated after the battery ...

AI Technical Summary

Problems solved by technology

The external heating method can meet the needs of low-temperature cold start to a certain extent, but it needs to add additional external heating equipment, which will inevitably take up extra space and weight and consume a lot of energy, and also increase the overall cost, so the internal heating The way will be the main trend of future development

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