Coal-fired secondary reheating steam turbine generator unit integrated with supercritical CO2 circulation

Abstract

The invention belongs to the technical field of secondary reheating steam turbine generating and energy saving and discloses a coal-fired secondary reheating steam turbine generator unit integrated with supercritical CO2 circulation. The unit comprises a coal-fired boiler, a secondary reheating steam turbine generator unit and a supercritical CO2 circulating generation system. Six-stage extractionsteam connected with a high pressure cylinder and an intermediate pressure cylinder is connected with steam-CO2 heat exchangers and enters corresponding feed water regenerative heaters after heatingCO2; in the CO2 circulating generation system, CO2 at an outlet of a compressor is divided into two streams, the two streams are heated by three stages of steam-CO2 heat exchangers respectively and are converged to enter a CO2 turbine for working, and CO2 exhaust enters the compressor after passing through a CO2-feed water heater and a CO2-air preheater sequentially; in a flue at the tail of the boiler, air is divided into two streams, and the two streams are preheated by the CO2-air preheater and a low-temperature air preheater respectively and are converged to enter a main air preheater. Bythe aid of the integrated system, the superheat degree of regenerative extraction steam of the secondary reheating unit and the exergy loss of air preheating are substantially reduced, the work of a steam turbine is increased, and the efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of double reheat steam turbine power generation and energy saving, in particular to an integrated supercritical CO 2 Cycle coal-fired double reheat turbogenerator unit. Background technique [0002] The climate problem of global warming is becoming more and more serious, and China, as the largest developing country in the world, currently uses coal-based primary energy and thermal power-based secondary energy structure, CO 2 Emissions are characterized by rapid growth and large volumes. China's national conditions, development stage and energy structure determine the effective use of CO 2 It is an important strategic choice for China to deal with climate change. CO 2 As a new generation of power cycle working medium, it has gradually attracted people's attention in many fields such as solar energy and geothermal energy. With the supercritical CO 2 Cycle power generation system and CO 2 In-depth resear...

AI Technical Summary

Problems solved by technology

In the double reheating system, the high-parameter steam generated after the first reheating and the second reheating of the boiler enters the high-pressure cylinder and the medium-pressure cylinder, and the steam with a high degree of superheat enters the regenerative heater. The heat transfer temperature difference is very large, the irreversible loss increases, and the economy of the unit is affected

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