Device for protecting air preheater against blockage by combining sound wave and hot air

Abstract

The invention discloses a device for protecting an air preheater against blockage by combining sound wave and hot air. The device comprises a three-branch-bin rotary air preheater, wherein a first sound wave soot blower is arranged on one side of the top of the three-branch-bin rotary air preheater, an air leakage side collecting cover is arranged on the other side of the top of the three-branch-bin rotary air preheater, an air inlet air collecting cover is arranged at the bottom of the three-branch-bin rotary air preheater, a second sound wave soot blower is arranged on the air inlet air collecting cover, the air leakage side collecting cover is connected with the input end of a circulating fan through an air leakage side collecting pipeline, the output end of the circulating fan is connected with a circulating flue gas spraying pipe through a circulating flue gas pipeline, and the circulating flue gas spraying pipe is connected with the air inlet air collecting cover. According to the device, the NH4HSO4 and the fly ash scale layer which are condensed in the flue gas are released through the combination of high intensity sound wave and hot air circulation, the temperature of thecold end of the air preheater is further increased through the hot air recirculation, so that the problems that the pressure difference between the inlet and outlet of the air preheater is gradually increased and the blockage is serious are solved.

Description

technical field [0001] The invention relates to a device for preventing blockage of an air preheater and low-temperature corrosion of a heat exchange surface combined with sound waves and hot air, and relates to the technical fields of blockage, corrosion prevention and control of an air preheater of a boiler in a coal-fired power plant, and air preheater transformation. Background technique [0002] In recent years, with the rapid development of modernization, under such a large environment, the construction of power plants has faced great challenges. In order to improve the quality of boilers, it is necessary to continuously strengthen the energy-saving transformation of boiler rotary air preheaters. Among them, the energy-saving transformation of the rotary air preheater of the boiler is one of the main development prospects. During the operation of the air preheater, there will be serious problems such as large air leakage, high running resistance and ABS blockage. [00...

AI Technical Summary

Problems solved by technology

Among them, the energy-saving transformation of the rotary air preheater of the boiler is one of the main development prospects. During the operation of the air preheater, there will be serious problems such as large air leakage, high running resistance and ABS blockage.

[0003] After the high-temperature flue gas reacts in the SCR system, it enters the air preheater for heat exchange. The temperature at the cold end of the air preheater generally drops to 130°C-160°C. During this period, the SO in the flue gas 3 Condensation, thus causing corrosion to the heat exchange surface, at the same time, the SO condensed in the flue gas 3 and NH 3 The reaction produces NH 4 HSO 4 , NH 4 HSO 4 It has strong viscosity, which is also easy to adhere to the fly ash in the flue gas, which will cause the pressure difference between the inlet and outlet of the air preheater to gradually increase, and the blockage will gradually increase. To solve the problem of air preheater blockage, power plants usually use steam Soot blowing or the use of air heaters are used to alleviate the problem. On the one hand, this affects the economical efficiency of the unit and increases the coal consumption. On the other hand, the clogging problem cannot be fundamentally solved. Load factor

[0004] Power plants usually use steam soot blowing or use of air heaters to solve the above problems. On the one hand, the blockage cannot be solved, and on the other hand, the energy consumption is high.

In the Chinese patent with the publication number CN2265482, an anti-blocking device for boiler air preheater is disclosed. , the floating grid frame is suspended on the upper part of the air preheater by hanging springs, the ash removal spring is installed in the smoke pipe of the air preheater, and the weight is hoisted at the lower end of the ash removal spring, and the floating grid frame and the ash removal spring are generated by using the flue gas disturbance Ups and downs vibrate to continuously scrape off the fly ash adhered in the flue gas pipe to achieve the purpose of anti-blocking of the air preheater, but NH4HSO4 has strong viscosity, the scraping effect is not ideal, and the anti-blocking effect is poor

Among them, the invention patent CN105864816B adopts the method of hot primary air reverse circulation to suppress the solidification and blockage of ABS. Although the adhesion of ABS is alleviated to a certain extent, the fouling inside the air preheater compartment cannot be effectively removed.

[0005] Therefore, it is very important to develop a high-efficiency and energy-saving method to solve the problems of large air leakage rate of air preheater, serious blockage of heating surface and high running resistance

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