Heat Exchanger Of The Heat Recovery Boiler

The heat exchanger in a heat recovery boiler plays a vital role in recovering and utilising the waste heat generated during the combustion process. Heat recovery boilers are commonly used in industrial environments such as power plants and manufacturing plants to capture and reuse otherwise wasted heat.

A general overview of heat exchangers in heat recovery boilers is as follows:

Function:

The primary function of a heat exchanger in a heat recovery boiler is to transfer heat from the hot flue gases (exhaust gases) produced during the combustion process to another fluid, usually water. This recovers heat energy that would otherwise be wasted.

Design:

The heat exchanger in a heat recovery boiler can be of a variety of designs, including shell and tube, plate, or finned tube configurations. The exact design depends on factors such as the temperature and pressure of the flue gas and the fluid being heated.

Exhaust Gas Passage:

Hot flue gases from the combustion process flow through one side of the heat exchanger. These flue gases may contain a significant amount of heat energy that can be transferred to the working fluid.

Working Fluid Passage:

On the other side of the heat exchanger, a different fluid, usually water, is usually circulated. This fluid absorbs heat from the flue gases and undergoes a phase change (usually to steam) or temperature increase.

Increased efficiency:

The overall efficiency of a heat recovery boiler is improved through the heat exchanger because it captures waste heat and uses it to preheat the working fluid. This preheating reduces the amount of fuel needed to reach the desired operating temperature, resulting in energy savings.

Preheating feedwater:

In many heat recovery boilers, the working fluid is typically the feedwater that will be supplied to a separate boiler. By using the recovered heat to preheat the feedwater, the overall efficiency of the entire steam generation process is improved.

Materials:

Materials used for heat exchangers depend on operating conditions, including factors such as temperature and corrosion. Commonly used materials include stainless steel, carbon steel, or other alloys that can withstand flue gas conditions.