Power station system and method for realizing semi-coke low NOx blended combustion through chemical chain air separation

Abstract

The invention discloses a power station system and method for realizing semi-coke low NOx blended combustion through chemical chain air separation. Oxygenation high-temperature reductive combustion, chemical chain air separation and semi-coke preheating system are mainly included, large proportion, low NOx and high-efficiency mixed combustion of a semi-coke low-volatile fuel with coal in a power station boiler can be realized, and the economic and environmental benefits of a power plant are remarkably improved. An optimized metal oxygen carrier is selected, pure oxygen prepared by a chemical chain air separation principle is fed into a hearth through secondary air or a wall type air nozzle, it is guaranteed that excess oxygen coefficient of a main combustion area is lower than 0.8, and a reductive high-temperature oxygenation area is created; a chemical chain air separation device is utilized to obtain high-temperature oxygen-poor air to preheat the semi-coke fuel, the furnace inlet temperature is increased, and the problem of difficult combustion is solved; combustion air adopts high oxygen concentration air or pure oxygen to improve the combustion efficiency of the fuel; and oxygen generated by a reduction reactor is carried by the extraction steam of a steam turbine and is condensed and separated by a low-pressure heater of the power plant, so that the energy consumption ofan air separation system is greatly reduced.

Description

technical field [0001] The invention belongs to the field of thermal power generation, in particular to a semi-coke low-NO x Mixed firing power plant system and method. Background technique [0002] The clean and efficient utilization of coal is still one of the focuses in the energy field in recent decades. The cascade utilization of coal quality, including coal liquefaction, gasification, and pyrolysis, is one of the key technologies. The related coal chemical industry has developed rapidly in my country and is widely distributed. Semi-coke is a solid product of low-temperature pyrolysis of low-rank coal, and its large-scale and clean utilization is one of the keys to the graded utilization of coal. With the development of my country's low-rank coal graded conversion industry, coal gasification, coking and other industries will produce hundreds of millions of tons of semi-coke and residual carbon every year. An effective method is to burn and utilize low-volatile fuels ...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a power plant system and method for realizing semi-coke low-NOx blended combustion through chemical looping air separation, which can realize a large proportion of semi-coke blended combustion in power plant boilers, and obtain high-temperature oxygen-deficient through chemical looping air separation technology Air and high-purity oxygen, using high-temperature oxygen-poor air to preheat semi-coke fuel, inject high-purity oxygen into the main combustion zone, and create an oxygen-enriched, high-temperature and strong reducing atmosphere under the condition that the excess oxygen coefficient of the main combustion zone is controlled below 0.8. At the same time, solve the NO produced during the combustion of semi-coke fuel x High emissions and poor ignition, stable combustion and burnout performance, etc., realize large-scale, efficient and clean combustion of semi-coke low-volatile fuels, and improve the economic benefits of power plants

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