Novel air preheater system for coal-fired power plant and work method thereof

Abstract

The invention discloses a novel air preheater system for a coal-fired power plant and a work method thereof. An inlet main flue communicates with a branch flue A and a branch flue B which are parallel. The branch flue A is provided with a tubular air preheater. The branch flue B penetrates through a rotary type air preheater and is internally provided with an adjusting baffle. A primary air inletpipeline and a primary air outlet pipeline are both connected with the tubular air preheater. A secondary air pipeline penetrates through the rotary type air preheater. The inlet end of a primary airbypass is connected with the primary air outlet pipeline. The outlet end of the primary air bypass is connected with an outlet of the secondary air pipeline. The tubular air preheater and the second branch bin rotary type air preheater are combined in parallel, a primary air system and smoke are isolated, the influence of high-pressure primary air on the air leakage rate of the air preheaters, thetwo means of the primary air bypass and the adjusting baffle are adopted, the air temperature of hot primary air can be adjusted, and the zero mixing amount of cold air is achieved.

Description

technical field [0001] The invention relates to a novel air preheater system and its working method in a coal-fired power plant. Background technique [0002] At present, the flue gas system of large-scale coal-fired boilers in large power plants is generally equipped with two 3-chamber rotary air preheaters. Due to the sealing problem of the preheater, the air leakage rate of the air preheater is relatively large. For example, the Chinese patent application number is 201721321397.X. The main reason is that the primary air pressure is 10KPa, which is about 4 times the secondary air pressure. High, the primary air is easily leaked to the flue gas side, which contributes the most to the air leakage rate. A large air leakage rate of the air preheater will easily lead to an increase in the power consumption of the induced draft fan and the primary fan. For units with insufficient rated fan output, a large air leakage rate will seriously affect the load carrying capacity of the ...

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Problems solved by technology

However, the increase in the primary cold air volume entering the pulverizing system will lead to a decrease in the air volume passing through the air preheater, an increase in the exhaust gas temperature, and a decrease in boiler efficiency.

[0004] In order to achieve a lower air leakage rate of the air preheater and no cold air in the pulverizing system, it is difficult to solve this problem for the air preheater system and pulverizing system of the coal-fired boiler in the power station. Therefore, a new type of air preheater for a coal-fired power plant is developed. System and method, it is very necessary to realize lower air leakage rate and zero mixing of cold air

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