A fuel cell recovery method

Abstract

The present invention proposes a fuel cell recovery method, which includes the following steps: S1, detecting the attenuation ratio of the output rated power of the fuel cell system; judging whether the attenuation ratio of the rated power is greater than the attenuation threshold; S2, checking whether the system meets the recovery conditions; S3 , Gradually reduce the cathode inlet pressure, maintain the anode inlet pressure higher than the cathode pressure, and gradually reduce the average single-chip voltage V0 by V1; if the minimum single-chip voltage is lower than the lowest rated average single-chip voltage V2, increase the reaction gas inlet pressure to make the minimum The cell voltage is higher than the minimum rated average single-chip voltage V2; S4, by reducing-increasing the inlet pressure of the reaction gas in the cycle step 3, the performance recovery of the fuel cell system is completed. Through this method, the activation process of the fuel cell stack can be completed on the whole vehicle, the driver does not have to drive the vehicle to the designated maintenance point, and the recovery process of the stack is more timely, which can effectively avoid affecting the stack due to untimely recovery. service life.

Description

technical field [0001] The invention relates to the technical field of fuel cell engine systems, in particular to a fuel cell recovery method. Background technique [0002] The fuel cell stack is one of the core components of the fuel cell engine system. It is a power generation device composed of hundreds of single cells connected in series. During the long-term operation of the fuel cell system on the vehicle, it needs to experience dynamic working conditions such as start-stop, load cycle, and low-temperature cold start in practical applications. Dynamic working conditions include physical and chemical aspects. Physical aspects: During the dynamic selection process of the vehicle, the transient changes in current loads cause frequent fluctuations in reaction gas pressure, temperature, humidity, etc., resulting in mechanical damage to the material itself or the component structure. Chemical aspects: Due to the change of dynamic process load, voltage fluctuations are cause...

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Problems solved by technology

[0003] Chinese patent CN101582513B discloses a proton exchange membrane fuel cell activation method: the steps are: ① supply air to the cathode, supply hydrogen to the anode, and maintain the open circuit voltage; ② cut off the air supply to reduce the open circuit voltage; ③ supply air to restore the voltage to the initial open circuit voltage; By cycling the open circuit voltage between 0.2V and 0.9V, the oxide layer on the surface of the cathode catalyst is reduced to realize the recovery process of the electrode performance. Although this method can restore the performance of the fuel cell, it will cause irreversible damage, that is, the fuel cell is in a long-term open circuit state. In this case, the proton exchange membrane in the electrode will be greatly irreversibly attenuated, and the service life of the fuel cell will be rapidly reduced.

[0004] On the other hand, in a low potential environment, impurities in the air such as sulfide will be adsorbed on the surface of the catalytic layer to form a sulfide film (Pt-SO3-, etc.), and the sulfide adsorbed on the surface of the catalytic layer during normal operation of the vehicle cannot Desorption leads to the deterioration of the fuel cell. With the accumulation of sulfide adsorption, the performance of the fuel cell is seriously attenuated and the vehicle cannot be operated.

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