What are the different types of air preheaters?

There are two types of regenerative air preheaters: the rotating-plate regenerative air preheaters (RAPH) and the stationary-plate regenerative air preheaters (Rothemuhle).

How do you preheat the combustion of air?

Heating combustion air can raise boiler efficiency about 1% for every 40F in temperature increase. The most common way to preheat the air is with a heat exchanger on the flue exhaust. The heat exchanger can be either air-to-air or air-to-liquid-to-air.

Why do we preheat the combustion of air?

For fuel-fired industrial heating processes, one of the most potent ways to improve efficiency and productivity is to preheat the combustion air going to the burners. The source of this heat energy is the exhaust gas stream, which leaves the process at elevated temperatures.

What is the function of air heater?

The purpose of the air preheater is to recover the heat from the boiler flue gas which increases the thermal efficiency of the boiler by reducing the useful heat lost in the flue gas.

Why does combustion air need to be preheated?

For fuel-fired industrial heating processes, one of the most potent ways to improve efficiency and productivity is to preheat the combustion air going to the burners. The source of this heat energy is the exhaust gas stream, which leaves the process at elevated temperatures.

How do you calculate the heat of combustion?

Calculating the Heat of Combustion Using Hess’ Law Write the balanced equation of combustion of the substance. Find the enthalpies of formation for the reactants and add them. Find the enthalpies of formation of the products and add them. Subtract the enthalpies of the reactants from the product. Switch the sign and that is the Heat of Combustion.

Why is air preheated in a thermal power plant?

Air Preheater in Thermal Power Plant As the entire heat of the flue gases cannot be extracted through the economizers, air preheaters are used to recover some of the heat from these gases. On an average increase of 20°C in the air temperature results in an increase in the boiler efficiency by 1%.

What is boiler combustion air?

Combustion is the reaction of fuels with oxygen in air to create heat that is used for steam production. A variety of fuels can be used for boiler combustion, including natural gas, fuel oil, and biofuels produced from plants or animal wastes.