Supercritical co2 Brayton cycle coal-fired power generation tail high temperature flue gas waste heat utilization system

Abstract

The invention discloses a supercritical CO2 Brayton cycle coal-fired power generation tail high-temperature smoke afterheat utilization system, and belongs to the field of efficient power generation equipment. Flowing of a supercritical CO2 working medium in a boiler of the system adopts a flow separation configuration mode; a tail air preheater in a smoke afterheat recovery system adopts a double-stage arrangement form; and circulation introduces a reheating and intermediate cooling arrangement form. Through flow separation configuration of the working medium in the boiler, the pressure dropof the boiler can be reduced; through double-stage arrangement of the tail air preheater, secondary air can reach a preset value, remained heat of tail smoke incapable of being absorbed by the air preheater is further absorbed, and the smoke discharge heat loss of the boiler is reduced; and a smoke cooler cooperates with the air preheater to solve the tail smoke afterheat absorption difficulty. The system solves multiple key problems in supercritical CO2 Brayton cycle and coal-fired thermal power generation coupling, and is simple in arrangement, stable in operation parameter and higher in thermal system and boiler efficiency.

Description

technical field [0001] The invention belongs to the field of high-efficiency power generation equipment, in particular to a supercritical CO 2 Brayton cycle coal-fired power generation tail high temperature flue gas waste heat utilization system. technical background [0002] As a primary energy source, coal plays an important role in the global energy structure. It has large reserves, is easy to mine, and has rich experience in use. Taking China as an example, coal accounts for 75% of China's primary energy consumption structure, accounting for the world's total coal consumption. a quarter of. Especially in the power sector, thermal power units account for more than 70% of the total installed capacity, most of which are coal-fired steam turbine power stations. However, the use of coal has increased the burden on environmental protection and the greenhouse effect. Under such circumstances, the development of advanced power cycle technology to improve unit performance is of...

AI Technical Summary

Problems solved by technology

The intercooling will reduce the power consumption of the compressor, and at the same time, it will appropriately reduce the temperature of the working fluid at the boiler inlet, which can be reduced by about 5°C under the calculated working conditions, but the intercooling will have an impact on the operating characteristics of the low temperature regenerator

Heat recovery can reduce the loss of cold source and improve cycle efficiency, especially the shunt recompression heat recovery arrangement, and make the heat capacity of the working fluid on the cold and hot sides of the low-temperature regenerator close to each other, improving the heat recovery effect, but the heat recovery will also increase the CO 2 The temperature of the working fluid at the boiler inlet

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