Laird Nextreme NRC1200 Series, Manual

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36
Chiller Operation
The chiller unit consists of the following subunits:
1. Refrigeration Circuit
The refrigeration circuit consists of evaporator, compressor, condenser, expansion valve and
refrigerant. The coolant returning from the customer’s application exchanges with the
refrigerant in the evaporator. The evaporated refrigerant is compressed by the compressor and
sent to the condenser. In the condenser, heat is rejected from the refrigerant to the ambient air
with the help of the condenser fan. Here refrigerant is condensed and enters the electronic
expansion valve. The expansion valve cools the liquid refrigerant which then goes to the
evaporator to exchange heat again with the coolant and this cycle continues. The system also
consists of a ‘Hot gas bypass valve’ in the heating loop, where the condenser coil and
expansion valve are bypassed partially or completely. The refrigerant flows through this loop
for cases where the customer load is too low or where raising the temperature of the coolant is
necessary to maintain stable application temperature.
2. Coolant Circuit
This circuit consists of the evaporator, coolant tank, pump and coolant. Temperature of the
coolant is regulated in the evaporator which then enters the coolant tank. This coolant is
circulated by the pump to maintain the customer application temperature. Coolant from the
customer application is circulated back to the evaporator and this cycle continues.
3. Control Panel
The control panel is responsible for the interaction of the different components with each other
and to integrate the sensors in order to achieve the required temperature setpoint. This is also
used for monitoring the state of the system.
Additional information on the system can be found in the Plumbing & Refrigeration Diagram and Wiring
Diagrams.