Tail gas combustor and solid oxide fuel cell system

Abstract

The invention belongs to the field of combustors, and discloses a tail gas combustor and a solid oxide fuel cell system.The tail gas combustor comprises a shell, a heat conducting fire-resistant baffle, a first porous medium, a second porous medium and a third porous medium, and the pore diameter of the first porous medium, the pore diameter of the second porous medium and the pore diameter of the third porous medium are sequentially increased; the downstream end of the shell is connected with a mixture air outlet pipe, the upstream end is connected with an air inlet pipe and a fuel gas inlet pipe; the third porous medium is arranged in the shell, the cross section of the third porous medium is U-shaped, an opening of the third porous medium faces the upstream end, and the first porous medium and the second porous medium are arranged on the inner side of the third porous medium at intervals; the heat-conducting fireproof baffle is arranged between the inner side surface of the third porous medium and the outer side surfaces of the first porous medium and the second porous medium; the air inlet pipe is communicated with the first porous medium and the third porous medium, the fuel gas inlet pipe is communicated with the first porous medium, and the mixed gas outlet pipe is communicated with the third porous medium. According to the invention, the tail gas combustion with higher temperature and wide-range excess air coefficient can be met.

Description

technical field [0001] The invention relates to the field of burners, in particular to an exhaust gas burner and a solid oxide fuel cell system. Background technique [0002] Solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) has the advantages of high efficiency, low pollution, good fuel adaptability, low noise, and does not require expensive catalysts. SOFC has strict requirements on the working temperature, generally between 600°C and 1000°C, the exhaust temperature is high, and the waste heat can be used to form a fuel cell-gas turbine combined power generation system, a fuel cell-cogeneration system, etc.; in addition, the high-temperature exhaust heat is also It can be used to preheat fuel cell inlet air and water to improve overall efficiency. [0003] SOFC anode tail gas usually contains unreacted fuel, and its residual chemical energy can be burned by combustion. At present, some SOFC tail gas burners have been reported in literatures and patents at home and abro...

AI Technical Summary

Problems solved by technology

However, this kind of burner has limited applicability. When the average temperature of the anode and cathode tail gas is high (such as exceeding 700°C), it is easy to burn in the steam reforming stage (at this time H 2 High ratio) uncontrollable spontaneous combustion endangers the safety of the system, and even an explosion may occur in severe cases; and when the excess air coefficient is too large (such as exceeding 10), the premixed fuel will be excessively diluted, exceeding the lean-burn limit and cannot be ignited or fire

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