What Is The Working Principle of An Air Preheater?

What is the Working Principle of an Air Preheater?

The working principle of an air preheater is mainly based on the heat exchange principle.

Take the rotary air preheater as an example, it mainly consists of a rotor, a shell, a transmission device and so on. The rotor is equipped with a number of heat storage elements and is divided into several fan-shaped compartments.

When working, the flue gas enters the air preheater from one side and passes through the heat storage elements to transfer the heat to them. With the slow rotation of the rotor, these heat storage elements turn to the other side, when the air enters from the other side and absorbs the heat on the heat storage elements, thus being heated. In this way, a continuous heat transfer between the flue gas and the air is realised by the constant rotation of the rotor.

In this process:

The heat of the flue gas is gradually transferred to the heat storage element.

The air is warmed up by the heat gained from the heat storage element.

Tubular air preheaters work on the principle that air and flue gases flow in separate tubes and exchange heat through the tube walls.

For example, in industrial boilers, the air preheater uses the high-temperature flue gas to heat the cold air that is about to enter the furnace, which improves the effect of combustion and energy efficiency. Another example, in some large thermal power plants, efficient air preheater operation can significantly reduce fuel consumption and pollutant emissions.

In short, the air preheater through clever design and structural arrangements, to achieve the heat transfer between the flue gas and air, to improve energy efficiency plays an important role.