Lignite pre-drying supercritical CO2 power generation system and method integrated with compression heat pump

Abstract

The invention discloses a lignite pre-drying supercritical CO2 power generation system and method integrated with a compression heat pump. The lignite pre-drying supercritical CO2 power generation system comprises a supercritical CO2 coal-fired power generation system and a lignite pre-drying system, and the supercritical CO2 coal-fired power generation system comprises a boiler, a main compressor, a re-compressor, a turbine, a low-temperature heat regenerator, a high-temperature heat regenerator and a pre-cooler; the lignite pre-drying system comprises a flow regulating valve, a condenser anda compression type heat pump system; the compression type heat pump system absorbs system cold end waste heat with high temperature, so that the evaporation temperature is improved, power consumptionof the compressor is reduced, and then the performance coefficient of the heat pump is improved; and the condenser in the compression type heat pump system releases heat to achieve the purpose of lignite pre-drying. According to the lignite pre-drying supercritical CO2 power generation system, the compression heat pump is used for converting the system cold end waste heat with higher temperatureto dry lignite, so that on one hand, the cold source loss of the system can be reduced; and on the other hand, moisture in lignite can be reduced, the heat value of the lignite is increased, the boiler efficiency can be improved, the station service power is reduced, and thus the system energy utilization efficiency is greatly improved.

Description

technical field [0001] The invention relates to the technical field of power generation, in particular to lignite pre-drying supercritical CO with integrated compression heat pump 2 Power generation systems and methods. Background technique [0002] Supercritical CO 2 The power cycle has the advantages of high thermal efficiency, simple system, high flexibility, small investment and low operation and maintenance costs, and has broad application prospects in the field of coal-fired power generation. Studies have shown that compared with conventional steam Rankine cycle coal-fired power generation units, coal-fired power generation systems based on supercritical CO2 power cycles have higher power generation efficiency and lower investment, and are expected to be applied on a large scale. However, supercritical CO 2 The heat release temperature of the working medium at the cold end of the coal-fired power generation system is high, and the waste heat loss is relatively large...

AI Technical Summary

Problems solved by technology

However, due to the high moisture content of lignite, the calorific value is low, the energy utilization efficiency of the direct-fired lignite power generation system is low, and the equipment cost is high

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