Fuel cell hydrogen supply system and control method

Abstract

The invention relates to the technical field of fuel cells, and discloses a fuel cell hydrogen supply system and a control method. The system comprises a control module, at least two ejectors and a fuel cell stack, each ejector is provided with a first ejection inlet and a second ejection inlet, and the ejectors are used for outputting hydrogen introduced from the first ejection inlets and the second ejection inlets; an anode gas inlet of a fuel cell stack is correspondingly connected with an output end of an ejector, anode gas outlets of all the fuel cell stacks are communicated with one another, and the anode gas outlets of the fuel cell stacks output excessive hydrogen to all the second ejection inlets; and the control module regulates and controls the hydrogen mixing proportion of the anode gas inlet of the fuel cell stack according to the internal hydrogen humidity of the fuel cell stack. According to the invention, the plurality of fuel cell stacks are connected, so that the hydrogen circulates among the plurality of fuel cell stacks, and the abnormal fuel cell stacks can be adjusted by using the fuel cell stacks in normal operation, so that mutual active adjustment among the stacks is realized.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a fuel cell hydrogen supply system and a control method. Background technique [0002] Due to its high power density and high energy conversion rate, fuel cells have become one of the main ways of using hydrogen energy. The fuel cell system includes a hydrogen circulation subsystem, which continuously provides a certain pressure and flow of hydrogen to the stack to ensure that The efficient operation of the stack can be said that the hydrogen circulation system has a great influence on the efficiency, reliability and life of the fuel cell. [0003] The hydrogen supply system supplies excess pure hydrogen to the anode of the fuel cell. After the anode reacts, usually unreacted hydrogen is discharged from the anode exhaust port. The hydrogen discharged from the anode of the fuel cell stack usually has three processing modes: flow mode, dead end mode and circulation mode. In th...

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Problems solved by technology

In the circulation mode, the hydrogen discharged from the anode directly enters the atmosphere through the exhaust valve, which will cause waste of hydrogen and pollute the environment; in the dead-end mode, the hydrogen exhaust valve is closed. In this mode, the excess hydrogen can completely react , but the water vapor produced will continue to accumulate, which will easily cause flooding of the fuel cell, reducing the efficiency and life of the fuel cell; the cycle mode is to transport the unreacted hydrogen to the anode hydrogen inlet again, and reuse the hydrogen, improving the efficiency of the fuel cell. The efficiency of the fuel cell stack, it can be said that the cycle mode is a development direction of the hydrogen supply system

[0004] However, the circulation mode of the existing hydrogen supply system is to use a single fuel cell stack to process the hydrogen cycle. The system of a single fuel cell stack cannot realize the active regulation of hydrogen supply. When the gas flow rate drops, the performance of the injector also decreases It will decline accordingly. In addition, after the fuel cell stack discharges the hydrogen, it needs to separate the hydrogen from steam and water. When the hydrogen is transported to the anode inlet of the fuel cell stack again, it needs to be humidified. There are many procedures.

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