Energy-saving recycling system for low-grade heat energy in smoke pollutant treatment of thermal power plant

Abstract

The invention provides an energy-saving recycling system for low-grade heat energy in smoke pollutant treatment of a thermal power plant. The system comprises a smoke cooler, a smoke reheater and a smoke auxiliary heater; an energy-saving branch for recycling the low-grade heat energy of the thermal power plant is arranged between the smoke cooler and the smoke reheater, and a first absorption heat pump and a water-water heat exchanger are arranged on the energy-saving branch; the first absorption heat pump comprises an absorber, a condenser, an evaporator and a generator; and according to the energy-saving recycling system for the low-grade heat energy in smoke pollutant treatment of the thermal power plant, it is ensured that under the condition that a smoke pollutant treatment system keeps stable running, an original smoke cooler is used for heating boiler condensate water so as to reduce coal consumption, and the water-water heat exchanger is matched with the first absorption heat pump to effectively recycle the low-grade heat energy in circulating water so as to heat medium water drained out of the smoke heater; and water resources are saved, and the comprehensive energy utilization rate of running of the pollutant treatment system is improved.

Description

technical field [0001] The invention relates to a pollutant treatment system of a thermal power plant, in particular to a low-grade heat energy recovery and energy-saving system in the treatment of flue gas pollutants in a thermal power plant. Background technique [0002] With the improvement of air pollutant emission standards for thermal power plants in my country, all newly built, under construction and active thermal power units need to adopt advanced flue gas clean emission technology to achieve ultra-low emission of air pollutants. According to the current technical level, the co-processing process of flue gas pollutants based on flue gas cooling and reheating technology is recognized as the main technical route to achieve ultra-low emissions from coal-fired power plants. [0003] Its working principle is that the flue gas cooling and reheating technology includes two gas-water heat exchangers, one is the flue gas cooler, which is usually located on the flue between t...

AI Technical Summary

Problems solved by technology

When the thermal power unit is operating at full load, but in winter and other climates, the temperature of the exhaust gas flowing out of the air preheater is low or the thermal power unit is not operating at full load, resulting in low exhaust gas temperature and flue gas flowing out of the air preheater. When the flow rate is reduced, because the flue gas outlet temperature of the flue gas cooler and the flue gas reheater needs to be maintained at a state similar to that at full load, the heat obtained by the flue gas cooler cannot meet the needs of the flue gas reheater. Usually, it is necessary to add a certain amount of steam with certain parameters to heat the heat medium water flowing out of the flue gas cooler to ensure that the flue gas temperature at the outlet of the flue gas reheater reaches about 80°C

According to the actual operating experience of thermal power units that have been put into operation, when the load of thermal power units is lower, the amount of supplementary steam is more, and the energy consumption of the ultra-low emission treatment system for flue gas is greater

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