A High Fuel Efficiency Internal Cascade Solid Oxide Fuel Cell Stack

Abstract

The invention relates to an inner cascaded solid oxide fuel cell stack with high fuel utilization rate. Fuel is input to the inner primary stack through a main fuel supply pipeline; air is input to the inner first stack and the inner second stack through an air inlet. The tail gas of the inner first-stage stack enters the inner second-stage stack through the cascade circulation loop; the fuel is supplied to the inner second-stage stack through the auxiliary fuel supply pipeline; the inner second-stage stack discharges the tail gas through the exhaust gas discharge pipeline. The present invention adds a cascading circuit, which improves the fuel utilization rate; adds an inner first-stage electric stack at the middle position, and ensures partial reforming reactions in the inner first-stage electric stack by managing the fuel gas components in the main fuel supply pipeline, thereby improving the power efficiency. The uniformity of the internal temperature field of the stack reduces the internal temperature of the battery stack and reduces the parasitic power of the fan; the auxiliary fuel supply pipeline is added to improve the controllability of the temperature and gas components of the mixed fuel gas entering the inner secondary stack.

Description

technical field [0001] The invention relates to the technical field of solid oxide fuel cells, in particular to an internally cascaded solid oxide fuel cell stack with high fuel utilization. Background technique [0002] Solid Oxide Fuel Cell (SOFC) is a clean and efficient power generation device, which works at high temperature (600oC-1000oC), can directly use various hydrocarbon fuels such as methane, and convert the chemical energy in the fuel directly into electrical energy. The SOFC single cell and core components such as connectors and seals form a repeating unit, and multiple repeating units are stacked to form a solid oxide fuel cell stack. Due to the relatively simple preparation process of the planar solid oxide fuel cell and the high working current density, it has received widespread attention and key promotion at home and abroad. In recent years, the demand for high-power battery stacks has become increasingly urgent, and problems such as low primary fuel util...

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Problems solved by technology

[0003] In order to improve the performance of solid oxide fuel cell stacks, the existing battery stacks usually improve the fuel utilization rate by reducing the intake flow of fuel gas or increasing the operating current of the stack. Attenuation acceleration and other issues greatly affect the life of the battery stack; on the other hand, the cooling of the existing battery stack mainly depends on the cathode air, and the temperature of the stack is adjusted by adjusting the cathode air flow, but the above method will increase the parasitic consumption of auxiliary equipment such as fans. Power, which affects the net power generation efficiency of the system, greatly limits the promotion and application of solid oxide fuel cell technology

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