Electronic Expansion Valves (EEV)
Electronic expansion valves differ to the normal thermostatic expansion valves in their
ability to maintain control of the suction superheat at reduced head pressures. This
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temperatures.
EEV step position, superheat setpoint, head pressure set point and other features can be
viewed and adjusted via the microprocessor display.
Whilst offering versatile control at the full design duty of the unit, Thermostatic Expansion
Valve’s (TEV) do not automatically optimise themselves to all operating conditions.
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at a lower ambient temperature than that for which the valve was sized, the conventional
TEV must have the design head pressure available to ensure good refrigerant control.
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Using an EEV allows for good refrigeration control whilst operating at part load and lower
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EEV’s differ to normal thermostatic expansion valves in their ability to maintain control
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rate of a typical EEV is superior to that of it’s thermostatic equivalent, such that a reduced
optimum condensing pressure can be maintained at low compressor load. However low
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Key:
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(2) Cooling cycle @ 22°C ambient, demonstrating a typical EEV condensing temperature taking full advantage of lower
ambient air temperatures (below 35°C).
Heat of Rejection
Reduction in
Compressor Input
Power
Enthalpy kJ/kg
Increase in
Cooling Duty
Evaporating
Pressure
Reduced
Condensing
Pressure
Presssure
Bara
Thermostatic Expansion Valve (1)
Electronic Expansion Valve (2)
1
2
3
4
Precision Air Conditioning
SmartCool™ 16 - 60
11
SmartCool Technical Manual 7525371 V1.2.0_03_2013
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Содержание R410A
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