Air-cooled fuel cell system and coupling heat control method thereof

Abstract

The invention discloses an air-cooled fuel cell system and a coupling heat control method thereof. The method comprises the following steps of: acquiring the current environment temperature of a fuel cell; acquiring the current working temperature of the fuel cell; controlling the rotation direction of a fuel cell fan according to the environment temperature; and controlling the rotation speed of the fuel cell fan according to the working temperature of the fuel cell. The rotation direction and rotation speed of the cooling fan are controlled according to the acquired working temperature and environment temperature of the fuel cell by virtue of the heat coupling characteristic of hydrogen desorption for heat absorption of an alloy hydrogen storage container and reaction for heat release of the fuel cell, so that effective coupling heat control over the hydrogen storage container and the fuel cell is realized, the hydrogen desorption efficiency of the hydrogen storage container at low environment temperature can be improved, the working conditions of the fuel cell at high environment temperature are improved, and the environmental adaptability of the air-cooled fuel cell system is further improved.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a heat control method coupled with an air-cooled fuel cell system. Background technique [0002] A fuel cell is a power generation device that converts the chemical energy of the reacting substances into electrical energy through an electrochemical reaction. Since its power generation process does not involve the combustion of fuel, it is not limited by the Carnot cycle and has high energy conversion efficiency. Fuel cells generally use As a reactive substance, hydrogen and oxygen also have the advantages of high power density and energy density, clean and efficient, and a wide power range. They have broad application prospects in mobile power supplies, household power supplies, transportation, distributed power stations, and submarines. [0003] Fuel cells convert chemical energy into electrical energy using an electrochemical reaction, which is an exothermic reaction that produces ele...

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Problems solved by technology

[0007] However, the existing technology does not consider the impact of environmental conditions on the fuel cell system, and its thermal control methods cannot be adjusted with changes in environmental conditions to maintain stable and efficient operation of the system.

For example, when the ambient temperature is low, the hydrogen storage device needs heat to release hydrogen, and the normal operation of the fuel cell also requires a certain amount of heat to maintain a suitable working temperature. The existing passive heat control method through the coupling of the alloy hydrogen storage device and the fuel cell structure There are obvious shortcomings. While the hydrogen storage device releases hydrogen, it has been continuously absorbing the heat generated by the fuel cell. If the battery is in the low-power operation stage (such as the start-up stage), the heat generated by the battery is not much. The heat is absorbed by the hydrogen storage device, which is not enough to maintain the normal working temperature, causing the fuel cell temperature to be too low and difficult to operate (start); and because the heat absorbed by the hydrogen storage alloy is not completely equal to the heat generated by the fuel cell reaction As well as the heat loss in the heat transfer process, the passive thermal control method cannot guarantee the control accuracy of the fuel cell operating temperature, so it cannot guarantee that the fuel cell works at the optimum temperature

When the ambient temperature is high, the ambient hot air can be used as the heat source of the heat absorbed by the hydrogen storage alloy when dehydrogenation, and there is no difficulty in dehydrogenation of the hydrogen storage device. The existing auxiliary equipment such as fans is used to transfer the heat of the fuel cell to the heat source of the hydrogen storage device. There are obvious deficiencies in the control method. At this time, the temperature difference between the optimum operating temperature of the fuel cell and the ambient temperature is relatively small. To maintain the fuel cell at the optimum temperature, the only way to increase the speed of the fuel cell fan is to increase the air flow, and the fuel The excess heat generated by the battery is discharged to avoid overheating of the fuel cell, but this will cause the membrane electrode of the fuel cell to be blown dry, which will cause the performance of the fuel cell to decline

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