Air heating reflux system for low-temperature starting of fuel cell and control method

Abstract

The invention relates to an air heating reflux system for low-temperature starting of a fuel cell. The system is used for accelerating low-temperature starting of the vehicle fuel cell. The system comprises a sensor assembly, a fuel cell stack, an outlet back pressure valve, an air filter, an air compressor, an intercooler and a humidifier, the air filter, the air compressor, the intercooler and the humidifier are successively connected through pipelines, and the humidifier is connected with the outlet back pressure valve and the inlet and the outlet of the fuel cell stack through pipelines; the system further comprises a heater, an inlet three-way valve arranged between the air filter and the air compressor, and an outlet three-way valve arranged between the humidifier and an outlet of the fuel cell stack, the inlet three-way valve is connected with the outlet three-way valve through a pipeline, and the heater is arranged between the inlet three-way valve and the outlet three-way valve. Compared with the prior art, the system has the advantages that rapid heating, normal starting and working of the fuel cell can be achieved without adding a large amount of additional accessory equipment.

Description

technical field [0001] The invention relates to the technical field of fuel cells for vehicles, in particular to an air heating recirculation system and a control method for starting a fuel cell at low temperature. Background technique [0002] A fuel cell is a power generating device that directly converts the chemical energy of fuel into electrical energy. As long as the fuel and oxidant are continuously supplied, the fuel cell will continuously output electricity and heat. It has the advantages of high power generation efficiency, low noise, and zero emissions. It is considered to be one of the cleanest and most efficient new energy power generation devices and can be widely used in the automotive field. [0003] The proton exchange membrane fuel cell is an electrochemical power generation device that uses hydrogen as fuel and oxygen as the oxidant. The electrochemical reaction produces water. At low temperatures, the water generated by the fuel cell may freeze, and the ...

AI Technical Summary

Problems solved by technology

Chinese patent CN 102386430A, through the design of the system, a desiccant, heating wire, circulation pump, etc. are installed at the air outlet and hydrogen outlet of the stack to store the stack at low temperature, but this method has high energy consumption for long-term parking. The system design is complicated and other disadvantages, which is not conducive to the actual application of the project

[0005] The "heating" method is divided into two categories according to the heat source: one is the external heat source, that is, the heat is mainly generated outside the stack and then transferred to the inside of the stack and each subsystem through a heat-conducting medium. For example, US Patent US 688760 adds a catalytic The reaction heater heats the coolant and then heats the stack. Although the energy is high and the heating is rapid, it reduces the fuel economy and greatly increases the complexity of the system. It is difficult to control the combustion of hydrogen and oxygen in the combustion chamber.

The other type is internal heating. This energy is mainly generated internally. For example, hydrogen and oxygen are directly passed into the cathode or anode for catalytic combustion to release heat. The heat released is large, but the uneven distribution of heat may cause thermal stress damage to the stack. , thus causing direct damage to the stack and reducing the life of the fuel cell stack

[0006] To sum up, the existing technology requires a large amount of additional auxiliary equipment, which not only increases the difficulty and volume of the design of the vehicle fuel cell system, but also increases the cost, and consumes additional fuel, reducing the fuel economy, and at the same time affect security

Images