High Heat Exchange Performance Boiler Air Preheater for Coal-Fired Power Station Boilers

General Introduction: Air Preheater

Air preheater is a kind of preheating equipment that improves the heat exchange performance of the boiler and reduces heat loss. It can conduct the heat carried in the flue gas discharged from the flue at the tail of the boiler to the air before entering the boiler through the heat sink to preheat the air to a certain temperature.

Air preheater is mostly used in coal-fired power station boilers. It can be divided into two types: tube box type and rotary type, of which the rotary type is divided into two types: wind hood rotary type and heating surface rotary type. Power station boilers often use rotary preheaters on the heating surface. The application in boilers is generally two-bin, three-bin, and four-bin, of which four-bin is more commonly used in circulating fluidized bed boilers.

Working Principle

Taking the rotary air preheater as an example to illustrate the principle of air preheater, it will rotate slowly during operation, the flue gas will enter the flue gas side of the air preheater and then be discharged, and the heat carried in the flue gas will be absorbed by the heat sink in the air preheater, and then the air preheater rotates slowly, the heat sink moves to the air side, and then the heat is transferred to the air before entering the boiler.

The application of air preheater in boiler is mostly three-compartment type, with fire alarm system, gap adjustment system and frequency conversion control system. Air preheaters are easy to use, simple to operate, safe to operate, and can improve the heat exchange performance of the boiler system, so it is very commonly used in flue gas boiler systems.

Details

The main heat transfer component of tubular air preheater is thin-walled steel tube. The tubular air preheaters are mostly cubic. The steel tubes are arranged vertically and staggered with each other. Both ends are welded on the upper and lower tube sheets.The tubular air preheater is equipped with an intermediate tube sheet in the tube box. The flue gas passes through the preheater up and down the pipe, while the air passes through the preheater horizontally to complete heat transfer.

Tubular air preheater is widely used in power station boilers and industrial boilers because of its advantages of good sealing, high heat transfer efficiency, easy manufacturing and processing. The shortcomings of tubular air preheater are large volume, easy ash plugging of steel tube content, difficult cleaning and easy wear and tear at flue gas inlet.