This module discusses the design and operation of the equipment used in vapor-compression refrigeration systems. The compressor is the heart of the system; it adds the energy that is needed to transfer heat out of the system and it causes the refrigerant to flow. As the refrigerant travels around the closed loop system, moving heat from one location to another, it flows through a system of piping, tubing, fittings, and valves. Several types of valves are used, and the most important is the expansion valve. The expansion valve controls the flow of refrigerant to the evaporator, which ultimately determines the capacity of the system. Other valve types, receivers, liquid-line filter driers, and accumulators are also covered.
Learning Objectives
At the end of this module, you will be able to:
- State the purpose of the compressor in the vapor-compression refrigeration cycle
- Describe hermetic, semi-hermetic, and open-type compressor housings
- Describe the design and operation of reciprocating, rotary vane, scroll, screw, and centrifugal compressors
- List major design considerations for a refrigeration piping system
- Discuss the use of copper, aluminum, and steel in piping systems
- Discuss soldered, brazed, flared, and quick-connect piping connections
- Describe the operation of various types of expansion valves
- State the functions of accumulators, receivers, filter-driers, and common valve types in refrigeration systems