What is the function of an economizer in a boiler?

The function of an economizer in a boiler is to recover heat from flue gases. This component is essential in improving the efficiency of the boiler system. Flue gases, which are the byproducts of combustion, still contain a significant amount of heat when they exit the boiler.

By utilizing an economizer, this residual heat is captured and used to preheat the feedwater before it enters the boiler. This process enhances overall thermal efficiency because it reduces the energy required to heat the incoming water, ultimately lowering fuel consumption and operational costs.

Other options do not align with the purpose of an economizer. For instance, providing oxygen for combustion is the role of the air supply system, regulating pressure involves safety valves and pressure controls, and storing excess water pertains to steam drums and other water management systems within the boiler setup. Thus, the primary and key function of an economizer distinctly focuses on heat recovery from flue gases.