Daikin GYEQ20AN Service Manual page 29

SiAUY361411EA
5.1.3 Heating Main B / Heating Mode Operation
• High-temperature, high-pressure refrigerant gas compressed by the compressor is fed to the
• The outdoor electronic expansion valve (and indoor electronic expansion valve on the cooling
• It is outdoor heat exchanger F/B (and the indoor heat exchanger on the cooling side) that
• The refrigerant that has passed through outdoor heat exchanger F/B (and the indoor heat
∗ The operations in parenthesis ( ) are not performed in the heating mode.
GYEQ20AN
Oil separator
Compressor 1
Compressor 2
∗ The actuators and refrigerant flow may vary depending on the control.
Device Overview
indoor heat exchanger on the heating side, which in turn condenses the refrigerant gas and
heats the indoor air by radiating the condensation heat; this is where the refrigerant changes
from gas to liquid.
side) depressurize the liquid refrigerant to facilitate refrigerant evaporation in outdoor heat
exchanger F/B (and the indoor heat exchanger on the cooling side) and the waste heat
recovery device.
function as the evaporator, which deprives the air of evaporation heat by changing the
refrigerant from liquid to gas. (The indoor unit on the cooling side cools the indoor air through
this evaporation heat deprivation process.) Also, the refrigerant that has passed through the
waste heat recovery device completely evaporates and deprives the gas engine cooling water
(hot water) of heat.
exchanger on the cooling side) is fed to the waste heat recovery device, which in turn
completely evaporates the refrigerant by mixing it with high-temperature, high-pressure
refrigerant and then returns it to the compressor. This completes one cooling/heating cycle.
Outdoor heat exchanger F Outdoor fan
Outdoor heat exchanger B
Oil
cooler
Accumulator
(Discharge gas)
(Intake gas)
(Liquid)
Receiver
Waste heat
recovery
device
System Diagrams
BS unit
Indoor unit
BS unit
Indoor unit
SV : Solenoid valves CV : Check valve
EV : Electronic expansion valve BV : Stop valve
TD : Discharge temperature HPS : Hi g h-si d e pressure swi t ch
TS : Intake temperature PH : High pressure sensor
TO : Oil temperature PL : Low pressure sensor
TREC : Receiver temperature
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