What is the function of economizers in a power plant?

The function of economizers in a power plant is primarily to recover waste heat from the flue gases and use it to preheat the boiler feedwater. By capturing heat that would otherwise be lost, economizers improve the overall efficiency of the boiler system. This process allows the boiler to require less fuel to achieve the same level of heating, since part of the energy needed for heating the feedwater has already been provided by the recovered waste heat.

Preheating the feedwater not only enhances efficiency but also helps in reducing the thermal shock experienced by the boiler components, thus contributing to their longevity and reliability. By utilizing the heat that is present in the exhaust gases, economizers play a crucial role in optimizing fuel consumption and reducing operational costs, making them an essential component in modern power plant design and operation.