Method and system for controlling air intake humidification amount of a fuel cell vehicle

Abstract

The invention discloses a method for controlling the humidification amount of intake air of a fuel cell vehicle, which includes: (1) starting the fuel cell system, if starting at normal temperature, enter step (2); if starting at low temperature, the humidifier does not perform humidification, Use dry air to purge the stack at low temperature until it reaches the normal temperature start-up condition; (2) Calculate the basic amount of humidification and the compensation amount of humidification, and add the two to obtain the actual intake humidification amount, which is consistent with the humidifier's permission Compare the maximum humidification amount, take the smaller one to get the actual humidification amount, and control the humidifier; (3) judge in real time whether the fuel cell demand power is greater than 0, if so, execute steps (1) and (2) in a loop to increase the intake air The humidity will be automatically adjusted; if not, it will enter the shutdown process. The invention controls whether the stack needs to be humidified and the amount of humidification by identifying the ambient temperature, the temperature of the air entering the stack, the AC impedance of the stack and the accelerator pedal, so that the fuel cell stack can use dry air to The purge of the stack does not humidify the air entering the stack, the purge time is short, and the fuel utilization rate is high.

Description

technical field [0001] The invention belongs to the fuel cell vehicle control technology, in particular to the fuel cell vehicle intake air humidification amount control technology. Background technique [0002] During the normal operation of the fuel cell stack, the proton exchange membrane is in a water-infiltrated environment. The protons pass through the proton exchange membrane from the anode to the cathode and combine with oxygen ions to generate water molecules, complete the electrochemical reaction, and generate electricity. The water content of the proton exchange membrane has a very important impact on the operating state and service life of the fuel cell stack. Too low water content in the proton exchange membrane not only affects the output characteristics of the stack, but also causes irreversible damage to the life of the membrane. [0003] The prior art method to solve the above problem is to mainly adopt an external membrane humidifier for humidification, and...

AI Technical Summary

Problems solved by technology

The water content of the proton exchange membrane has a very important impact on the operating state and service life of the fuel cell stack. Too low water content in the proton exchange membrane not only affects the output characteristics of the stack, but also causes irreversible damage to the life of the membrane.

[0003] The method of the prior art to solve the above-mentioned problems is to mainly adopt an external membrane humidifier for humidification, relying on the matching of the membrane humidifier and the humidity of the fuel cell stack at the design stage to ensure the humidity required by the stack. This humidification method The disadvantage is that the humidity of the air entering the stack is uncontrollable, so that the fuel cell stack cannot work under the optimal humidity conditions, thus affecting the performance and durability of the entire fuel cell system

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