A water management method for a fuel cell stack

Abstract

The invention relates to a water management method for a fuel cell stack. A gyroscope is installed in a vehicle equipped with a fuel cell engine system. The gyroscope is connected to the control system of the fuel cell stack of the fuel cell engine system. The gyroscope The instrument perceives the stable condition of the vehicle running. If the gyroscope detects that the vehicle is turning, climbing or descending, it will feed back to the control system of the fuel cell stack. The control system controls the stoichiometric ratio of the hydrogen side to be 1.3-6 Increase by 5% to 40% on the basis of 1.5 to 6, and / or increase by 5% to 40% on the basis of controlling the stoichiometric ratio of the air side at 1.5 to 6. Compared with the prior art, the present invention has the advantages of facilitating the drainage of the fuel cell, alleviating the rapid drop of the single cell voltage of the electric stack caused by turning, climbing or descending, and improving the service life of the electric stack.

Description

technical field [0001] The invention relates to the technical field of fuel cell stacks, in particular to a water management method for fuel cell stacks. Background technique [0002] Although the industrialization of fuel cell system components has reached a small scale, water management is still a very critical issue, and it has not been fully resolved so far. High-quality water management should achieve a balance between the water content in the membrane, the anode proton electric drag (EOD, electro-osmotic drag) water and the cathode reverse osmosis water, and at least ensure that the reaction gas is not transported to the reaction interface due to liquid water. The obstacles caused by the large fluctuations in performance should also ensure that the proton conduction process does not cause a significant decrease in performance due to water shortage. However, in actual operation, it is difficult to achieve the above two points at the same time, so there will be problems...

AI Technical Summary

Problems solved by technology

When the stoichiometric ratio of the hydrogen side is 1.5 and the stoichiometric ratio of the air side is 1.9, the second end plate is arranged in the direction of the front of the vehicle, the first end plate is the anode end plate, and the hydrogen inlet, air inlet and cooling water inlet are arranged at the first Take the end plate as an example, when the vehicle goes downhill, the anode end plate of the fuel cell stack is raised, and the lowest single cell voltage in the stack (the single piece with the lowest voltage is located at figure 2 and Figure 4 The position near the second end plate) decreases sharply over time, eventually leading to the failure of the stack

[0004] In order to solve the problem of flooding, the solution usually adopted in the prior art is to set up special drainage channels on the hydrogen side and the air side respectively. It will not gather at the end, but enter the drainage channel and then discharge the stack. However, adding a drainage channel will greatly change the structure of the stack, the operation is complicated and the cost is high, and it cannot solve the problem of rapid cell voltage when the stack is tilted. falling problem

In addition, the existing technology also estimates the amount of water discharged from the fuel cell based on the state of the fuel cell (residual water amount or inclination angle), thereby judging the intensity of subsequent purging, and solving the drainage problem by purging, so that the stack can start normally. Although this method can alleviate the flooding situation, this method still cannot avoid the problem that the lowest single battery voltage drops sharply due to the flooding of the single battery when the vehicle encounters climbing, descending, and turning situations during operation.

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