Supercritical carbon dioxide circulating fluidized bed coal fired boiler and power generation system driven by same

Abstract

The invention discloses a supercritical carbon dioxide circulating fluidized bed coal fired boiler. Supercritical carbon dioxide is adopted to replace steam in an existing circulating fluidized bed boiler to serve as a working medium for absorbing heat and acting, and the heat absorption process of the working medium comprises the steps of one-time flow division and one-time re-heating. The heating face of the working medium of the supercritical carbon dioxide circulating fluidized bed boiler comprises a carbon dioxide cold wall screen type heater and a high temperature reheater which are arranged in a hearth. An externally arranged a superior economizer treating dust as a heat source is arranged on a material recycling device section between an outlet of a separator and the hearth in parallel. A heating face in a rear smoke channel in the flowing direction of smoke comprises a low temperature reheater and a subordinate economizer. The invention further discloses a power generation system driven by the supercritical carbon dioxide circulating fluidized bed coal fired boiler to generate power. The supercritical carbon dioxide circulating fluidized bed coal fired boiler enhances smoke heat transmission of a high temperature section of the reheater, and meanwhile relieves heat demanded pressure of the rear smoke channel, the emission amount of pollutants can be effectively reduced, the smoke emission temperature can be effectively decreased, and the boiler efficiency is improved.

Description

Technical field [0001] The invention belongs to the field of thermal power generation equipment, and specifically relates to a supercritical carbon dioxide circulating fluidized bed coal-fired boiler and a power generation system driven by it. Background technique [0002] Increasing energy conversion rate, reducing pollutant emissions, and developing new environmentally friendly energy sources are the eternal theme of the thermal power industry. The traditional boiler system uses steam as the circulating working medium to realize energy conversion. The steam parameter can be increased to 700°C, and the efficiency can reach about 50%. However, it is difficult and costly to develop alloy materials that can withstand high temperatures of 700°C. Therefore, the high temperature resistance of the materials has become a major bottleneck restricting the efficient power generation of power plants. [0003] Supercritical carbon dioxide is a kind of supercritical fluid, its temperature and ...

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Problems solved by technology

[0005] The object of the present invention is to provide a circulating fluidized bed coal-fired boiler that can improve the thermal efficiency of the boiler, reduce pollutant emissions, and realize efficient and clean operation of the boiler, using supercritical carbon dioxide as a circulating working medium, so as to solve the problem of the steam temperature of the existing steam boiler. Problems that limit the improvement of efficiency

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