AEC Glacier Series Air and Water Cooler Portable Chillers - Manual (Page 36)

Glacier Series Portable Chillers Page 35
4 Sequence Of Operation
4-1 Chilled Water Circuit
Figures 15 to 19
Process cooling water supply and return connections are made at the gate valves provided
outside the unit. Warm coolant (water and ethylene glycol mixture) returns from the process and
goes into the reservoir tank. The coolant is then pumped through the evaporator where it is
cooled.
The coolant flows to the process and returns to repeat the cycle.
A chilled water bypass valve between the supply line and reservoir tank guarantees a constant
flow in the unit during intermittent fluctuating flow conditions.
4-2 Refrigeration Circuit
Glacier Series portable chillers are available with either air or water cooled refrigerant
condensing. The refrigeration cycles differ only in the way the compressed gas is condensed to a
liquid.
Liquid refrigerant from the condenser passes through a shutoff valve into a filter/dryer that
removes moisture and other contaminants. A refrigerant sight glass is provided. The refrigerant
then passes through the thermal expansion valve which allows the refrigerant to expand and cool
the inside of the heat exchanger. The refrigerant flows through the suction accumulator into the
compressor.
The refrigerant gives up its heat as it re-condenses to a liquid in the condenser. A hot gas bypass
valve is used to control cooling capacity during intermittent or partial load conditions. This
feature contributes substantially to chiller longevity by eliminating excessive cycling of the
compressor and providing close temperature control.