Coupling system and operation method of low temperature flue gas water recovery and waste heat utilization in coal-fired power stations

Abstract

The invention discloses a low-temperature flue gas water recovery and waste heat utilization coupling system and operation method of a coal-fired power station. device, low-temperature flue gas cooler, electrostatic precipitator, desulfurization tower, flue gas condenser, flue gas reheater, chimney, first and second air heaters, multiple circulating water pumps and multiple control valves; through multiple The flue gas heat exchanger recovers the waste heat of the low-temperature flue gas to the steam turbine recuperation system or is used for preheating the air to reduce the coal consumption of the unit; the water is recovered through the flue gas condenser; the flue gas is reheated through the flue gas reheater to reduce the impact on the chimney Low-temperature corrosion; the operation of the flue gas heat exchanger can be adjusted through the control valve, and it can work together with other flue gas heat exchangers in series under different working conditions to ensure that the temperature of the flue gas entering the electrostatic precipitator is maintained above 90°C, ensuring that the flue gas entering the electrostatic precipitator The circulating water temperature of the low-temperature flue gas cooler is above 70°C to meet the safe operation of the system under different ambient temperatures.

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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