Fuel cell gas circulation system and control method

Abstract

The invention belongs to the technical field of fuel cells, and particularly relates to a fuel cell gas circulation system and a control method. According to the fuel cell gas circulation system disclosed by the invention, the multiple ejectors are connected in parallel, one part of the ejectors eject non-condensable gas of fuel cell anode exhaust gas, the other part of the ejectors eject condensate water of the fuel cell anode exhaust gas, a three-way valve is arranged on an ejection flow pipeline of the ejector, and ejection fluid can be switched. According to the requirements of the operation condition of the battery, the components of the gas entering the reformer are flexibly adjusted, and the injection ratio of the ejector and the water-carbon ratio entering the reformer are decoupled.

Description

technical field [0001] The present application belongs to the technical field of fuel cells, and in particular relates to a fuel cell gas circulation system and a control method. Background technique [0002] Solid Oxide Fuel Cell (hereinafter referred to as SOFC) is a high-temperature fuel cell that uses the mixture of fuel and water vapor to undergo a reforming reaction in a reformer to produce hydrogen. Insufficient water content in the mixture will lead to reforming Carbon deposits inside the reactor and SOFC will seriously affect the performance and service life of SOFC. SOFC anode exhaust has the characteristics of high temperature, high water content (about 50% molar content), and some unreacted fuel. Therefore, anode gas circulation is often used to recover heat, water and fuel, so as to prevent carbon deposition. . Because the ejector has no moving parts, it is easy to maintain and has a long service life, so in the anode gas circulation loop of SOFC, the ejector ...

AI Technical Summary

Problems solved by technology

In this system, the amount of water vapor recovered depends on the injection ratio of the ejector and the water vapor content in the ejected flow, but since the water vapor content in the SOFC anode exhaust is determined by the battery itself, it is necessary for the recovery The amount of water vapor to achieve the required water-carbon ratio requires the ejector to have a very high injection ratio, and the current ejector design technology is difficult to meet the requirements; in addition, the existing technology directly ejects the SOFC anode exhaust, which is difficult to achieve The injection flow composition is adjusted to realize the decoupling of the injection ratio and the water-carbon ratio. These shortcomings greatly limit the practical application and working condition adaptability of the ejector.

Therefore, the existing technology has the disadvantages that the performance of the ejector is difficult to meet the required water-to-carbon ratio and the gas composition is difficult to adjust.

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