36 TRG-TRC003-EN
notes
period five
Review
Period Two discussed refrigerants and how they are used in the process of
removing and transporting heat.
Remember that refrigerants absorb significant amounts of heat when they
change phase (e.g., from a liquid to a vapor). Chemical refrigerants commonly
evaporate at low temperatures when exposed to atmospheric pressure.
Because of their cost and impact to the environment, however, refrigerants
must be recovered in a closed system.
Period Three presented the basic vapor-compression refrigeration cycle, and
specifically the use of a compressor, condenser, and expansion device to
“recover” the evaporated refrigerant and complete the cycle. The primary
components of the vapor-compression refrigeration cycle include the
evaporator, compressor, condenser, and expansion device.
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