YORK INTERNATIONAL
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REFRIGERATION OVERVIEW – CONT’D
Follow the flow diagram on page 13:
1. Cold, low pressure refrigerant, (low is typically
55-75 PSI for example) in a mix form of liquid and
vapor, enters the cooler tubes and evaporates (va-
porizes) as it chills the tubes and absorbs heat from
the water passing over the tubes. During this trans-
fer of energy, the water temperature drops, accom-
plishing the system objective.
2. Cool, low pressure vapor is drawn from the evapora-
tor and into the compressor, where pressure, and sub-
sequently the temperature, are increased. (High pres-
sure typically is in the 150-340 + PSI range).
3. The hot, high pressure vapor exits the compressor
and flows through an oil separator, then into the
condenser, warming the coils. The hot coils then
transfer heat from the vapor to the outside air that
is travelling through the coils. As the gas cools, it
condenses into a liquid. (Visible through the sys-
tem sight glass).
4. With sufficient cooling, a stream of warm, high
pressure pure liquid refrigerant exits the condenser.
It is then fed to an expansion valve, which controls
the flow of liquid refrigerant that is fed to the evapo-
rator.
5. A large change in system pressure, and subse-
quently, a change in temperature, occurs as the liq-
uid flows through the expansion valve. (See P-T
chart, page 16. Note temperature change as pres-
sure changes from 200 PSI to 60 PSI). This results
in a spray of cold, low pressure refrigerant, part
liquid, part vapor, exiting the expansion valve. This
cool mix then enters the cooler tubes, evaporates
completely, and the cycle is then repeated.
6. On some models, a small percentage of the of refrig-
erant is drawn off the main liquid refrigerant stream,
and fed to a small heat exchanger, called an econo-
mizer. This objective is to further cool the main
stream of liquid refrigerant being fed to the TXV.
This adds more load capacity to the system (at high
loads only).
Refrigeration Overview
