Device and method for spraying, cooling and eliminating white smoke in desulfurization tower of thermal power plant

Abstract

The invention relates to a device and method for spraying, cooling and eliminating white smoke in a desulfurization tower of a thermal power plant. The desulfurization tower is internally horizontallyequipped with a demister, a top water spray layer, a liquid holding device and a slurry spray layer from top to bottom successively. The slurry spray layer is located above an inlet of the desulfurization tower. The liquid holding device comprises a drainage port, a concave drainage tank, flue gas through-flow devices and a liquid holding layer; the peripheral edge of the liquid holding layer issurrounded by the concave drainage tank, and a number of liquid drainage outlets are arranged on the concave drainage tank; the upper surface of the liquid holding layer is surrounded by a number of flue gas through-flow devices. The device has the advantages of high device integration, simple operation, reliable operation, no damage to water balance of an absorption tower and no heat exchanger. Therefore, no risk of corrosion leakage of the heat exchanger exists, and the safety is high. By use of the method for eliminating white smoke, the latent heat of vaporization in flue gas is recovered,the heat loss of boiler exhaust gas is further reduced, the moisture carried in the flue gas is reduced, and white smoke plume at a chimney outlet is eliminated.

Description

technical field [0001] The invention relates to a device and method for spraying and cooling white smoke elimination in a desulfurization tower of a thermal power plant, and belongs to the field of flue gas purification and white smoke elimination of power plant boilers, metallurgical coking, and related industrial boilers. Background technique [0002] Coal-fired power plant boilers have a large proportion of exhaust heat loss during operation, accounting for more than 50% of the total boiler heat loss. Some thermal power plants operate with exhaust gas temperatures that are often higher than the design value. Therefore, reducing the exhaust gas temperature of power plant boilers has important practical significance for energy saving and emission reduction. At the same time, the flue gas generated during the operation of coal-fired power plant boilers contains not only a large amount of sulfur dioxide, but also a large amount of fine particles. One of the culprits, the rea...

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Problems solved by technology

In addition, because the flue gas discharged from the desulfurization outlet is saturated wet flue gas, it is mixed with cold air after being discharged from the chimney, causing the water vapor in the flue gas to condense suddenly to form white smoke, especially in winter, it is easy to cause visual pollution and affect the appearance of the environment

[0003] To deal with the white smoke problem of desulfurization flue gas in power plants, the method of flue gas reheating was used in the past. Many power plants used GGH (ie flue gas heat exchanger) in the early days, that is, the heat of high-temperature flue gas before desulfurization was used to heat the desulfurization. Flue gas, the temperature of the flue gas after heating is above 75°C. This solution has the effect of eliminating white smoke, but does not make full use of energy. At the same time, this method will cause acid dew point corrosion of equipment and problems of equipment blockage and leakage. Early use Most of the power plants have removed the GGH

In recent years, the methods of eliminating white smoke include MGGH, slurry condensation method and flue condensation method. MGGH is a water-medium heat exchanger. The solution is generally to install a cooling section heat exchanger at the entrance of the electrostatic precipitator. Install a heat exchanger in the heating section at the outlet, and use the heat of the flue gas before the electrostatic precipitator to heat the desulfurized flue gas. This scheme has played a role in eliminating white smoke to a certain extent, but the renovation project is relatively large and costly. The heat exchanger at the outlet of the desulfurization tower is prone to corrosion and leakage, and the economy is poor; the slurry condensation and white smoke elimination is to install a heat exchanger on the desulfurization slurry circulation pipeline to reduce the temperature of the slurry, thereby reducing the temperature of the desulfurization flue gas and reducing the moisture content of the flue gas , and then eliminate the method of white wet smoke plume, but this method is easy to destroy the water balance of the absorption tower, and there is a big safety hazard; flue condensation to eliminate white smoke is to install a heat exchanger in the outlet flue of the desulfurization tower to reduce the temperature of the flue gas at the desulfurization outlet , to reduce the moisture content of the flue gas, and then eliminate the white wet plume, but this method has high requirements for the material of the heat exchanger, but the transformation project is large and the cost is high, and the heat exchanger at the outlet of the desulfurization tower is easy Corrosion leakage, poor economy

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