Edwards TCU 40/80

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Bypass vaSn
Oran valve
I RID
temperature
probe
Profisure
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Figure 3- Refrigeration and coolant circuits
4.2 Refrigeration
(see figure 3 above)
1. Refrigerant gas enters the compressor at low temperature and pressure. It leaves the compressor at
high pressure and temperature.
2. The gas passes into the condenser, where heat is removed by the external water supply, causing the
gas to condense into a liquid.
3. The cool liquid refrigerant exits the condenser and passes through a filter dryer that removes any
residual moisture or contaminants.
4.2.1 If cooling is required:
1. Solenoid valve SV1 opens (coil energized), allowing the refrigerant to flow into the Thermostatic
Expansion Valve (TEV). The pressure drop across the TEV causes the refrigerant to change from a
liquid to a mixture of liquid and gas.
2. The liquid and gas mixture enters the heat exchanger where it becomes entirely a gas. The process of
expansion from a liquid to a gas reduces the temperature by absorbing energy.
3. The refrigerant leaving the heat exchanger returns to the compressor through the subcooler and a
crankcase pressure regulator. The subcoolcr further cools the refrigerant entering the TEV.
TCU 40/80 Temperature Control Unit