Solid oxide fuel cell

Abstract

A solid oxide fuel cell whose structure is simplified and where fuel gas is recirculated. [MEANS FOR SOLVING PROBLEMS] A solid oxide fuel cell has a fuel supply section (12) in which a stack (10) formed by alternately layering disc-shaped cells (1) and disc-shaped separators (2) is received in a casing (11) and that penetrates the central portion of an upper wall of the casing (11) and supplies fuel to the central portion of the stack (10); an air supply section (13) that penetrates the central portion of a lower wall of the casing (11) and supplies air to the central portion of the stack (10); a fuel sending section (14) that penetrates the lower wall of the casing (11) and sends fuel having been used for power generation from the central portion of the stack (10); a discharge gas sending section (15) that penetrates the peripheral edge of the lower wall of the casing (11) and sends discharge gas that is formed by mixing air and the fuel, having been used for power generation, and combusting the mixture; and a recirculation section (16) for mixing the fuel, having been used for power generation and sent from the fuel sending section (14), with fuel newly supplied.

Description

technical field [0001] The present invention relates to a solid oxide fuel cell in which a plurality of cells are assembled to form a cell stack, and the fuel remaining after power generation is in contact with air. Background technique [0002] Conventionally, among solid oxide fuel cells, it is known that flat-plate cells have a high power density of power generation. [0003] In addition, as a method of forming a battery pack by compactly arranging flat-shaped battery cells while reducing the number of sealing parts, it is known to stack disc-shaped flat-plate battery cells together with separators without sealing the periphery of the discs, and to seal the outer periphery of the battery. The fuel gas remaining after the reaction is mixed with an oxidizing agent-containing gas and combusted (see Patent Document 1). [0004] In the fuel cell described in Patent Document 1, fuel and air are supplied through the central part of the battery cell, the fuel and air flow from t...

AI Technical Summary

Problems solved by technology

[0009] On the other hand, in the case of adopting a structure with a seal portion on the outer periphery, when the seal length becomes longer, the seal structure becomes complicated in order to relieve stress, resulting in lower reliability, higher cost, larger shape, and accompanying larger size. problems such as increased heat loss caused by

If the sealing is omitted in consideration of these defects, it leads to the problem that the recirculation of the fuel gas is impossible

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