Functions of a Refrigeration Compressor

A refrigeration system and its components all work together to make up the refrigeration process. The refrigeration compressor is the heart of this process, and without it, nothing works. The function of the compressor is to increase the pressure of the refrigerant that has been vaporized throughout the refrigeration process. To comprehend the functions of a refrigeration compressor, a basic knowledge of how the refrigeration system works is imperative.

The understanding that refrigeration is the relocation of heat is first and foremost in understanding how the system works. Whether the refrigeration system is in a central air conditioning system or a refrigerator, the basic process is the same. Take it easy — this is not meant to bore you with crazy science that a refrigeration technician needs to know but rather to provide a basic understanding so you can better comprehend the functions of a compressor.

• A ​compressor​ is the pump that forces the refrigerant throughout the system. There are many types of compressors for many types of applications.

• A ​condenser​ is a series of coils that do as the name implies: condense the hot, high-pressure refrigerant gas from the compressor into a high-pressure liquid. This is where the absorbed heat from the evaporator is released during the refrigeration process.

• An ​evaporator​ is the refrigeration system component that absorbs the heat from the air while used in a central air conditioning system or refrigerator. Air is forced over a series of coils, much like in the condenser but having the opposite effect if used in a central air conditioning system. In a refrigerator, the evaporator can vary in design depending on the refrigerator, but the heat absorption for relocation is still the function as well. This is accomplished by high-pressure liquid refrigerant changing to a gas as it passes through an orifice of various types and is sized for the refrigeration system and whether it is a function of a refrigerator or central air conditioning.

• The ​expansion valve or orifice​ is where the magic really happens. The is the point in the system where the hot, high-pressure liquid vaporizes and turns into a cold, low-pressure gas. As the pressure and state of the refrigerant change from a liquid to a gas, it absorbs heat as it flows through the evaporator coil. Magic, right? Not really; it's just science.

• ​Refrigerant piping​ is the highway between the components that carries the traffic of heat relocation. There are two pipes: a smaller one and a larger one. The smaller one is the high-pressure liquid piping that feeds the thermal expansion valve or orifice at the evaporator. The larger pipe brings the low-pressure gas back from the evaporator to the compressor to start the whole process again.

Refrigeration compressors come in various shapes and sizes depending on the specific size and function of the compressor. The primary goal is to create a lower-pressure suction to be displaced into a higher pressure that will circulate the refrigerant throughout all the refrigeration system components effectively and efficiently.

• A ​reciprocating compressor​ uses a back-and-forth motion to compress the refrigerant gas to be sent through the system. An electric motor rotates and pushes a piston, drawing in the low-pressure refrigerant gas and displacing it, and increases the pressure of the refrigerant gas.
  
  
• A ​rotary compressor​ is one of the most common of the domestic central air conditioning and refrigeration systems. This is achieved by a motor turning a vane or a helical screw. As the vane or helical screw rotates, the low-pressure refrigerant gas is displaced, increasing refrigerant gas pressure and moving it throughout the refrigeration system components.

Safely and legally handling this equipment requires a good understanding of electrical and refrigeration and requires certifications. Always resort to refrigeration expertise for these needs.