Coal-fired power plant low-temperature flue gas water recovery and waste heat utilization coupling system and operation method

Abstract

The invention discloses a coal-fired power plant low-temperature flue gas water recovery and waste heat utilization coupling system and an operation method. The system comprises a rotary air preheater, a low-temperature economizer, a first part adjustable flue gas heat exchanger, a second part adjustable flue gas heat exchanger, a low-temperature flue gas cooler, an electric dust remover, a desulfurizing tower, a flue gas condenser, a flue gas reheater, a chimney, a first-stage air heater, a second-stage air heater, a plurality of circulating water pumps and a plurality of control valves. Low-temperature flue gas waste heat is recovered to a steam turbine regenerative system through the multiple flue gas heat exchangers or used for preheating air, and unit coal consumption is reduced; water is recovered through the flue gas condenser; flue gas is reheated through the flue gas reheater, and low-temperature corrosion to the chimney is reduced; and operation of the adjustable flue gas heat exchangers is controlled through the control valves, the adjustable flue gas heat exchangers are connected with other flue gas heat exchangers in series to work together under different working conditions, the temperature of the flue gas entering the electric dust remover is maintained to be 90 DEG C or above, the temperature of circulating water entering the low-temperature flue gas cooler is 70 DEG C or above, and therefore safe operation of the system under different environment temperatures is achieved.

Description

technical field [0001] The invention relates to the technical field of coal-fired power generation, in particular to a low-temperature flue gas water recovery and waste heat utilization coupling system and operation method of a coal-fired power station. Background technique [0002] The rapid development and continuous growth of my country's economy is inseparable from the stable and strong support of the energy industry. my country's fossil energy reserves determine that coal-fired power generation is still the main power generation method in my country in a short period of time. In recent years, my country has made great progress in the thermal power industry. Improving the efficiency and operational flexibility of coal-fired power stations, reducing pollutant emissions and resource consumption are long-term concerns of coal-fired power stations. Therefore, the deep utilization of waste heat in coal-fired power stations, thermal power units The continuous reduction of nitr...

AI Technical Summary

Problems solved by technology

However, the conventional flue gas water recovery and waste heat utilization system is an independent system, which causes the following problems:

[0005] 2. It is difficult for the low-temperature flue gas preheating and water recovery system to match the variable operating conditions of the unit, especially when the ambient temperature is low, it is easy to cause the flue gas entering the electrostatic precipitator to be too low, causing low-temperature corrosion

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