Coupling system of power generation, decarbonization and heat supply integration in new coal-fired power plant

Abstract

With the increase of energy demand, the accompanying environmental problems are also increasing. The CO2 generated by combustion is the direct source of greenhouse gases, and coal-fired power plants are the main source of carbon emissions, and a lot of waste heat is generated in the production process. The decarbonization system of coal-fired power plant and the cogeneration system have similar heat source temperature requirements. Therefore, the waste heat generated in the process can be recycled while controlling the carbon emissions of the coal-fired power plant, and the heating capacity of the system can be improved. Based on the power generation system of coal-fired power plant, solid amine absorbent decarbonization system and primary/secondary heating system, an integrated coupling system of power generation, decarbonization and heating is proposed innovatively. The back-pressure heating steam turbine and back-pressure decarburization steam turbine are introduced to replace the low-pressure steam turbine, and the exhaust steam of the back-pressure heating steam turbine and the back-pressure decarburization steam turbine provide heat sources for the heating process and the decarburization process respectively. On the premise of ensuring decarbonization capacity, the power generation capacity loss of the coupled system is significantly reduced. In order to further improve the thermal performance of the coupling system, the absorption heat transfer technology is used to recover the low-temperature waste heat released by the decarbonization system and improve the heating capacity of the coupling system. The calculation results show that more than 90% of the low-temperature waste heat released by the system is recovered by the new power-decarbonization and heat-supply coupling system. The heating capacity of the system is increased from 785.06 MW to 1 288.94 MW, and the heating capacity is increased by 65%.

Keywords

• post-combustion co2 capture
• combined heat and power generation
• waste heat recovery
• absorption heat exchange
• carbon neutrality