McQuay MHC Series, Установка и обслуживание данных, Страница: 33 / 36

IM 985-1 / Page 33 of 36
Figure 26. Cooling Mode
Return Air
Reversing Valve
Conditioned Air
(Cooling)
Thermal
Expansion Valve
Coaxial Heat
Exchanger
Blower
Coil – Air to Refrigerant
Heat Exchanger
Water In
Water Out
Sensing Bulb and
Capillary Tube
Compressor
Figure 27. Heating Mode
Return Air
Thermal
Expansion Valve
Coaxial Heat
Exchanger
Reversing Valve
Conditioned Air
(Heating)
Blower
Water In
Water Out
Sensing Bulb
and Capillary Tube
Compressor
Coil – Air to Refrigerant
Heat Exchanger
Cooling Refrigeration Cycle
When the wall thermostat is calling for COOLING, the reversing valve directs the flow of the refrigerant, a hot gas,
leaving­the­compressor,­to­the­water-to-refrigerant­heat­exchanger .­Here­the­heat­is­removed­by­the­water­and­the­
hot gas condenses to become a liquid. The liquid then flows through a thermal expansion metering system to the
air-to-refrigerant­heat­exchanger­coil .­The­liquid­then­evaporates­becoming­a­gas,­at­the­same­time­absorbing­heat­
and cooling the air passing over the surfaces of the coil. The refrigerant then flows as a low pressure gas through the
reversing­valve­and­back­to­the­suction­side­of­the­compressor­to­complete­the­cycle .­­
Heating Refrigeration Cycle
When the wall thermostat is calling for HEATING, the reversing valve directs the flow of the refrigerant, a hot gas,
leaving­the­compressor,­to­the­air-to-refrigerant­heat­exchanger­coil .­Here­the­heat­is­removed­by­the­air­passing­
over the surfaces of the coil and the hot gas condenses to become a liquid. The liquid then flows through a capillary
thermal­expansion­metering­system­to­the­water-to-refrigerant­heat­exchanger .­The­liquid­then­evaporates­becoming­
a gas, at the same time absorbing heat and cooling the water. The refrigerant then flows as a low pressure gas through
the­reversing­valve­and­back­to­the­suction­side­of­the­compressor­to­complete­the­cycle .­­
Typical Cooling and Heating Refrigeration Cycles