Method and system for controlling air intake humidifying amount of fuel cell automobile

Abstract

The invention discloses a method for controlling an air intake humidifying amount of a fuel cell automobile. The method comprises the following steps of: (1) starting a fuel cell system, if the fuel cell system is started at normal temperature, entering a step (2), if the fuel cell system is started at low temperature, enabling a humidifier not to carry out humidification, and using dry air for carrying out low-temperature starting-up purging on a galvanic pile until a normal-temperature starting-up condition is met; (2) calculating a humidifying basic amount and a humidifying compensation amount, adding the humidifying basic amount and the humidifying compensation amount to obtain an actual air inlet humidifying amount, comparing the actual air inlet humidifying amount with a permitted maximum humidifying amount of the humidifier, taking a smaller value to obtain an actual humidifying amount, and controlling the humidifier; and (3) judging whether the required power of a fuel cell is greater than 0 or not in real time, if so, circularly executing the steps (1) and (2) to automatically adjust the air intake humidifying amount, and if not, entering a shutdown process. Whether the stack needs to be humidified and the humidifying amount are controlled by identifying the environment temperature, the air in-stack temperature, the stack alternating current impedance and the accelerator pedal, so that the fuel cell stack is purged by using dry air without humidifying the in-stack air under the low-temperature starting working condition, the purging time is short, and the fuel utilization rate is high.

Description

technical field [0001] The invention belongs to the control technology of fuel cell vehicles, and in particular relates to the control technology of the intake humidification amount of fuel cell vehicles. Background technique [0002] During the normal operation of the fuel cell stack, the proton exchange membrane is in a water-soaked environment. 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 method of the prior art to solve the above-mentioned problems is to mainly adopt an external membrane hu...

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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