Daikin RXYQ5-48MAY1, Руководство по обслуживанию

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Si39-407 Outline of Control (Indoor Unit)
Function 111
6.7.2 Discharge Air Temperature Control
Used to control the EV (electronic expansion valve) opening and thermostat ON/OFF so as to
keep the discharge air temperature at the set temperature.
(1) Cooling operations
T1: Temperature detected by suction air thermistor Th1
T2: Temperature detected by liquid pipe temp. thermistor Th2
T3: Temperature detected by gas pipe temp. thermistor Th3
T4: Temperature detected by discharge air thermistor Th4
EV: Electronic expansion valve opening
Discharge
air
Refrigerant
Refrigerant
CPU
T1
T3
T2
T4
EV
Ts
Temp.
Setting
T4 > Ts?
Is EV possible
to open?
Is
EV possible to
close?
Calculate superheat degree.
If the discharge temperature
T4 is higher than the discharge
setting temperature Ts
Judge if the superheat degree
is not too small when the EV is
opened.
If yes,
EV is opened. If yes,
EV is closed.
Yes
Yes Yes
No
No No
If the discharge temperature T4
is lower than the discharge
setting temperature Ts
Judge if the superheat degree
is not too large when the EV is
closed.
SH=T3–T2
EV=EV+
∆
EV EV=EV–
∆
EV