Energy-saving and low-dust emission coal-fired power generation system

Abstract

The invention relates to an energy-saving and low-dust emission coal-fired power generation system. The energy-saving and low-dust emission coal-fired power generation system comprises a boiler, a desulfurization tower and an electrostatic dust collector. The energy-saving and low-dust emission coal-fired power generation system is characterized in that a waste heat recovery system is arranged in the upstream direction of the desulfurization tower, and a dedusting system is arranged behind the desulfurization tower; a waste heat recovery system is arranged in the upstream direction of the desulfurization tower; or a dedusting system is arranged behind the desulfurization tower. The waste heat recovery system recovers heat in a high-temperature flue gas at a tail part of the boiler and sends the heat into a steam turbine heater, and comprehensive utilization of flue gas waste heat is achieved through saving of extraction flow of the heater. The invention provides an energy-saving and low-dust emission coal-fired power generation system, clean emission in a true sense is achieved through the waste heat recovery system and the dedusting system, and the energy-saving and low-dust emission coal-fired power generation system is simple, reliable and efficient.

Description

technical field [0001] The invention belongs to the technical field of waste gas purification, and in particular relates to an energy-saving and low-dust emission coal-fired thermal power generation system. Background technique [0002] China is a typical coal-rich country, and its domestic electricity is mainly coal-fired thermal power generation. As of the end of 2013, my country's power generation installed capacity exceeded 1.2 billion kilowatts, of which thermal power was 862 million kilowatts, accounting for 69.13% of the total installed capacity. The installed capacity of coal power reached 786 million kilowatts. In the Beijing-Tianjin-Hebei-Shandong and Yangtze River Delta regions where smog is severe, the installed capacity of coal-fired power per unit of land area far exceeds that of the Northwest region, and the air pollution emissions per unit area are several times higher than the national average. [0003] Many cities are currently aiming at "coal-to-gas" as ...

AI Technical Summary

Problems solved by technology

The exhaust gas temperature of traditional power plant boilers is between 120 and 140°C. However, the wet desulfurization process widely used today requires the flue gas temperature to be reduced to about 50°C in the desulfurization tower by spraying, which not only consumes a lot of water And electric energy, but also increased flue gas emissions, exacerbated the phenomenon of gypsum rain around the power plant, so from the two aspects of energy saving, emission reduction and economical considerations, further reducing the exhaust gas temperature has become an inevitable choice for the development of energy saving and emission reduction technology for power plant boilers

[0008] Boiler flue gas waste heat recovery equipment is usually arranged in the tail flue where the flue gas temperature is relatively low. It is made of ordinary stainless steel metal pipes. Low-temperature corrosion and ash plugging will be caused by the back of the pipe wall, which seriously limits the service life of the equipment and reduces the economy and safety of waste heat recovery

Although low-temperature corrosion can be alleviated by using corrosion-resistant special alloy steel, it still cannot completely solve this problem. At the same time, the high cost of construction and maintenance also greatly reduces the economics of waste heat recovery

In order to avoid low-temperature corrosion problems in the project, the flue gas temperature after waste heat recovery is generally maintained above the acid dew point, usually at a minimum of 90°C. However, compared with the working temperature of 50°C in the desulfurization tower, there is a large amount of waste heat. be effectively recycled, and the flue gas still needs to be cooled by consuming water and energy

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