Novel supercritical CO2 compound circulation system applicable for field of coal-fired power generation

Abstract

The invention discloses a novel supercritical CO2 compound circulation system applicable for the field of coal-fired power generation, and belongs to the field of high-efficiency power generation equipment. The compound circulation system is composed of a top circulation system, a bottom circulation system and an air preheater heat absorption system, and heat generated by coal combustion in a boiler is absorbed by the three systems jointly, wherein the top circulation is secondary reheating and recompression circulation; the bottom circulation is graded heating circulation, and the bottom circulation system is composed of a bottom circulation cooler, a bottom circulation first compressor, a bottom circulation low-temperature regenerator, a bottom circulation second compressor diverter valve, a bottom circulation second compressor, a bottom circulation high-temperature regenerator, a first tail flue heater diverter valve, a first tail flue heater, a bottom circulation first turbine, a second tail flue heater and a bottom circulation second turbine. Through the bottom circulation, within the inlet temperature range of 580-640 DEG C of a top circulation turbine, the compound circulation system is higher in efficiency, and the safe operation of an air preheater is ensured.

Description

technical field [0001] The invention belongs to the field of high-efficiency power generation equipment, and in particular relates to a new type of supercritical CO2 suitable for the field of coal-fired power generation. 2 Compound circulatory system. technical background [0002] Supercritical carbon dioxide Brayton cycle (S-CO 2 In recent years, extensive research has been carried out in the fields of sodium-cooled fast reactor power generation, tower-type solar thermal power generation, and waste heat utilization of gas turbine flue gas. This study was carried out under the conditions of relatively mature technology related to the steam Rankine cycle because compared with the steam Rankine cycle S-CO 2 Loops can offer some very attractive advantages. [0003] For example, at the same turbine inlet temperature, S-CO 2 Compared with the steam Rankine cycle, the cycle can have higher efficiency in the medium isothermal region (550°C-700°C). In addition CO 2 It is chemi...

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Problems solved by technology

[0006] This problem can be solved by building a compound cycle, but different compound cycles have different solutions. If the compound cycle is not constructed properly, the power generation efficiency of the system will be reduced. The reduction in system power generation efficiency can be understood from two aspects. 1. If the flue gas If the waste heat is not fully absorbed, the boiler efficiency of the power generation system will decrease. 2. The waste heat of the flue gas is absorbed, but the cycle efficiency is low, so the cycle heat efficiency of the power generation system will decrease

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