Boiler step energy using system and method

Abstract

The invention discloses a boiler step energy using system and method. According to the boiler step energy using system and method, boiler tail fume and supercritical CO2 are subjected to heat exchange in a first heat exchanger, so that the temperature of the supercritical CO2 is raised; the warmed supercritical CO2 works outwards through a steam turbine and then is led into a second heat exchanger; and the supercritical CO2 is cooled after subjected to heat exchange with water in the second heat exchanger, and the cooled supercritical CO2 is subjected to isothermal compression in a gas compressor, and then led into the first heat exchanger or led into a third heat exchanger and then led into the first heat exchanger for circulation so as to achieve utilization of waste heat of the smoke. According to the boiler step energy using system and method, efficient and step utilization of the waste heat of the boiler tail fume can be achieved, and the boiler step energy using system and method have the advantages of being environmentally friendly, efficient, simple, low in cost and the like.

Description

technical field [0001] The invention belongs to the technical field of flue gas waste heat utilization, and more specifically relates to a boiler cascade energy utilization system and method. Background technique [0002] At present, the temperature of the flue gas at the tail of the boiler in the power plant is still as high as 130°C after passing through the air preheater and the dust collector. , this part of the heat is not effectively utilized and is directly lost, which reduces the energy utilization efficiency. [0003] At present, there are many schemes for industrial waste heat utilization systems in the prior art. For example, CN105298567A discloses an industrial waste heat utilization system using supercritical carbon dioxide working fluid. The compound circulation loop of the compound circulation loop, in which the compound circulation loop of the hierarchical series type includes a generator, a turbine, a regenerator, a cooler and a compressor. After passing th...

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Problems solved by technology

[0002] At present, the temperature of the flue gas at the tail of the boiler in the power plant is still as high as 130°C after passing through the air preheater and the dust collector. , this part of the heat is not used effectively and is directly lost, which reduces the energy utilization efficiency

[0003] At present, there are many schemes for industrial waste heat utilization systems in the prior art. For example, CN105298567A discloses an industrial waste heat utilization system using supercritical carbon dioxide working fluid. The compound circulation loop of the compound circulation loop, in which the compound circulation loop of the hierarchical series type includes a generator, a turbine, a regenerator, a cooler and a compressor. After passing through the turbine in the system, the working medium needs to be reheated by two regenerators Then through the cooler and the compressor in turn, that is, the working medium is heated first and then cooled, resulting in a waste of energy. It needs to be additionally equipped with a regenerator for heat recovery, and the circuit structure of the compound cycle is complicated, which increases the equipment investment cost. , and it does not give guidance on the specific layout of the waste heat utilization system

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