Horizontal And Vertical Type Steel Air Preheater For Boiler And Power Plant

Introduction

Air preheater is a kind of equipment which can improve the heat exchange performance of the boiler and reduce the energy consumption. The function of the air preheater is to heat the flue gas discharged from the tail flue of the boiler and transmit it to the air before entering the boiler through the radiator, so as to preheat the air to a certain temperature.

The air preheater is generally used for coal-fired boilers in power station.It can be divided into tubular type and rotary type. The rotary type can be further divided into wind hood rotary type and heating surface rotary type.Power stations usually use the heating surface rotary air preheater. Generally, the application in boilers is two-compartment, three-compartment and four-compartment, among which the four-compartment is more commonly used in CFB boilers.

Classification

According to the way of heat transfer, the air preheater can be divided into two types:heat conduction type and regeneration type.Among the heat conduction type, tubular air preheater is most commonly used.With the increase of boiler parameters and capacity, the heating surface of tubular air preheater increases, which brings difficulties to the arrangement of the tail heating surface. Therefore, most of the large capacity units adopt a compact, light weight rotary air preheater. Air preheater is generally divided into three types: plate type, rotary type and tubular type.

Functions

1. Improve and enforce combustion

The air through the heat exchanger enters the furnace, which accelerates the drying, ignition and combustion process of the fuel, ensures the stable combustion in the boiler and improves the combustion efficiency.

2, Enhance heat transfer

Because the combustion in the furnace has been improved and strengthened, and the temperature of hot air entering the furnace has been increased, the average temperature level in the furnace has also been raised, so the radiation heat in the furnace can be strengthened.

3,Reduce the loss of the furnace, lower the exhaust gas temperature and improve the thermal efficiency of the boiler

Because of the stable combustion in the furnace and the enhanced radiation heat exchange, the chemical incomplete combustion loss can be reduced. On the other hand, the air preheater uses the waster heat of flue gas to further reduce the loss of the exhaust gas, thus improving the thermal efficiency of the boiler. According to experience, when the air in the preheater rises by 1.5 degrees, the exhaust gas temperature can be reduced by 1 degree. After installation of the air preheater in the boiler, if the air temperature can be raised by 150-160 degrees by the waste heat, the exhaust gas temperature can be reduced by 110-120 degrees, and the thermal efficiency of the boiler can be increased by 7-7.5E%. Fuel can be saved by 11-12%.

4,Hot air can be used as fuel disiccant.

For layer boilers, if there is hot air, fuels with higher moisture and ash content can be used. For power station boilers, hot air is an important desiccant and pulverized coal conveying medium in grease powder system.

Certification