Air pre-heater

Abstract

The invention provides an air pre-heater. A temperature increase sector plate is arranged at the position, close to a secondary air side, on a smoke side. The included angle alpha between the temperature increase sector plate and a sector plate closest to the temperature increase sector plate ranges from 7 degrees to 8 degrees. The center angle beta of each separation bin is equal to the included angle alpha. The center angle gamma of the temperature increase sector plate ranges from 9 degrees to 10 degrees. The separation bin between the temperature increase sector plate and the sector plate closest to the temperature increase sector plate is a circulation smoke separation bin. One side of a smoke inlet above the smoke side is communicated with a bypass flue. The bypass flue is sequentially connected with a dust remover, a temperature increase smoke induced draft fan and a temperature increase smoke inlet again, and the temperature increase smoke inlet is communicated with the circulation smoke separation bin. Compared with the prior art, high-temperature smoke is guided to the cold end of the air pre-heater, and when the temperature of the cold end is above 147 DEG C, ammonium bisulfate is scaled and gasified again, and the clogging prevention effect is achieved. Through the action of the temperature increase smoke induced draft fan, positive-pressure smoke flow is formed between the smoke side and an air side, pressure of the positive-pressure smoke flow and pressure of positive-pressure air flow of secondary air restrain mutually, and the air leakage problem is effectively solved.

Description

technical field [0001] The invention relates to the technical field of thermal power generation, in particular to an air preheater capable of solving the problem of ash blocking and air leakage. Background technique [0002] The air preheater is referred to as the air preheater for short. It is generally divided into two types: tubular type and rotary type. At present, the rotary type air preheater includes a rotor centered on the rotor center cylinder. The rotor has multiple compartments. There are heat transfer elements, and there are generally three pairs of fan-shaped plates symmetrical up and down on the upper and lower sides of the rotor compartment. Two pairs of fan-shaped plates divide the rotor into two semicircles of the same size, thereby dividing the rotor into the smoke side and the air side. The air side and the air side are divided into the primary air side and the secondary air side through another pair of fan-shaped plates. The primary air on the primary air...

AI Technical Summary

Problems solved by technology

After the coal-fired boiler is put into the SCR denitrification system, the ammonium bisulfate scale on the heat transfer element of the air preheater cannot be removed by ordinary steam soot blowing. When the blockage is serious, it has to be shut down for high-pressure water flushing. Ammonium hydrogen scaling is the biggest factor that causes the boiler to fail to operate for a long time

[0006] At the same time, because the air preheater will undergo mushroom-shaped deformation after being heated, a certain gap will be formed between the sealing sheet on the air preheater and the fan-shaped plate. Since the air side of the air preheater is positive pressure airflow, and the flue gas side is negative pressure airflow, Therefore, the air flow on the air side will enter the flue gas side, resulting in the air leakage of the air preheater.

Air leakage will lead to poor thermal conditions of the unit, accelerate low-temperature corrosion, reduce thermal efficiency of the unit, increase fan power consumption, reduce boiler efficiency, and affect the overall operation of the unit

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