Condensers are heat engines that transfer heat from a hot working fluid (vapor or steam) and condense it into a liquid phase. Different industries can use this mechanism for a variety of purposes. For example, in the power generation industry, condensers can condense waste steam produced by turbines back into water so that it can be recycled to the heating plant. In the chemical processing industry, condensers transfer heat within a stream to condense various chemical vapors.
Depending on the application, the condenser must be able to withstand different pressure and temperature levels. Described below are the most common types of industrial condensers:
Air-cooled condenser: Mainly used in residential condensing units, these condensers use air as the medium to remove heat from the refrigerant flowing within the coil. However, the flow mechanism of these condensers can proceed in more than one way.
Natural Convection - When air contacts the coil, it absorbs heat from the refrigerant flowing inside. Then, as the color brightens, hot air rises and replaces the cold air. The cold air being pushed downwards comes into contact with the heat coil, absorbs the heat of the refrigerant and rises. This cycle continues until the refrigerant is sufficiently cooled.
Forced Convection - This condenser uses a fan or blower to force air along the condenser tubes.
Water-cooled condenser: As the name suggests, water-cooled condenser uses water as the coolant. Their complex and high-capacity designs are often preferred for industrial applications. Based on design and functionality, water-cooled condensers can be subdivided into the following categories:
Double Tube Condenser - These condensers have a large refrigerant tube that contains a water tube. The water absorbs heat from the refrigerant inside the tube, condenses it, and settles at the bottom of the tube. Heat also escapes through the openings in the tubes.
Shell and Coil Condensers - The refrigerant passes through a welded shell while water circulates through the coils to condense the refrigerant.
Shell and Tube Condenser - These condensers have a cylindrical steel shell containing straight water tubes. The refrigerant flows inside the casing, and the water in the tubes condenses the refrigerant.
Water-cooled condensers are common components in large refrigeration equipment and the chemical processing industry.
Evaporative condenser: This type of condenser combines the functions of an air-cooled condenser and a water-cooled condenser. Water is pumped and sprayed onto the refrigerant coils to release heat. At the same time, air is drawn from the inlet at the bottom of the condenser toward the coil to further cool the refrigerant. Evaporative condensers are commonly used in commercial HVAC applications.
Given the unique manufacturing requirements of each condenser type, many components must be welded together, and the quality of the welds affects the performance and reliability of the entire system.