Evaporators

The evaporator is one of the main components of a refrigeration system, in which refrigerant evaporates for the purpose of extracting heat from the surrounding air, chilled water, or other substances.

In an air cooler, the refrigerant flows inside the metal tubes or finned tubes while air flows over them.An air cooler is an evaporator that cools the air directly in a refrigerated space or piece of equipment (such as a packaged unit). Conditioned air is then distributed through air distribution systems.A liquid cooler is different from a chiller. A liquid cooler is an evaporator, a component of a refrigeration system, whereas a chiller is a refrigeration package to produce chilled water.In liquid overfeed evaporators, liquid refrigerant is fed by a mechanical or gas pump and is then overfed to each evaporator. The inner surface in an overfeed evaporator is also wetted by liquid refrigerant.Evaporators can be classified into three categories, depending on the medium or substance to be cooled:For more information visit us at: http://hvac-world.blogspot.com/1-Dry-expansion or direct-expansion (DX):An evaporator can be used to produce ice directly, such as an ice maker in an ice harvester of an ice storage system.3-Liquid overfeed:In vapor compression refrigeration systems, the evaporator is also an indirect-contact heat exchanger.In evaporators with dry- or direct-expansion refrigerant feed, liquid refrigerant is fed through an expansion valve and a distributer, flows inside the tubes in a finned coil, the evaporator, and is completely vaporized and superheated to a certain degree before reaching the exit of the evaporator.2-Flooded refrigerant feed:In a liquid cooler, chilled water is cooled to a lower temperature and is pumped to remote air handling units, fan coils, or other terminals for air conditioning or other applications.In evaporators with flooded refrigerant feeds, liquid refrigerant is fed through a throttling device and vaporizes outside the tubes within a shell. The refrigerant-side surface area is always wetted by the liquid refrigerant, which results in a higher surface heat-transfer coefficient.

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