Flue gas waste heat recovery system of 1000 MW secondary reheating power plant

Abstract

The invention relates to a flue gas waste heat recovery system of a 1000 MW secondary reheating power plant. The system comprises a flue gas bypass arranged on an air preheater of a boiler, wherein abypass primary high-temperature heater and a bypass secondary low-temperature heater are arranged on the flue gas bypass, the bypass primary high-temperature heater is used for heating high-pressure feed water at an outlet of a feed water pump of a turbine, and the bypass secondary low-temperature heater is used for heating condensed water; and the inlet end of a flue dust remover at the tail partof an outlet of the air preheater of the boiler is provided with a low-temperature low-pressure economizer, and the low-temperature low-pressure economizer is used for heating cold air at an inlet ofthe air preheater through circulating water. According to the system, the boiler flue gas waste heat is utilized to simultaneously heat the condensed water, the cold air and the feed water, so that the energy level of low-temperature flue gas is improved, the waste heat utilization efficiency is greatly improved, the standard coal consumption of a unit is further reduced, the purposes of energy conservation and emission reduction are achieved, and the thermal economy of the unit is improved.

Description

technical field [0001] The invention belongs to the technical field of thermal power generation, and in particular relates to a 1000MW secondary reheat power plant exhaust waste heat recovery system. Background technique [0002] With the rapid development of my country's economy, the demand for electricity is increasing year by year, and more and more large-scale coal-fired thermal power generating units are put into use, which also makes the supply of coal resources increasingly tight. The power generation efficiency of generator sets and the reasonable and effective use of limited coal resources are particularly important. [0003] Power plant boilers are the most energy-consuming equipment in power plants, and are also the source of a series of energy-consuming processes in power plants. In order to generate the steam driven by the prime mover for power generation and ensure a large working capacity, the power station boiler consumes a large amount of coal resources. ...

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Problems solved by technology

[0005] At present, the existing flue gas waste heat utilization scheme in power plants is mainly to install low-temperature economizers at the inlet of the dust collector and the outlet of the induced draft fan in the tail flue of the boiler. ℃, the recovered flue gas waste heat generally replaces the last few stages of the steam turbine recuperation system with low-pressure steam extraction, which can reduce the standard coal consumption of the unit by about 1-2g / kw.h, and the energy level of flue gas waste heat utilization is low

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