Electronic expansion valve for precision control (LEEV)
Funtion
Precision control (expansion→evaporation)of refrigerant flow as a core part of cooling cycle.
Features
Multi-control is possible with electronic control device.
Strong point
It can be utilized in many ways irrespective of type of refrigerant.
Outdoor unit of air conditioner : LEEV
Electronic valve device to expand and evaporize liquid refrigerant by precision control of fluid quantity & temperature of air conditioner refrigerant through electronic control&multi-control
Basic specifications
BASIC REFRIGERATING CYCLE AND ROLES OF EXPANSION VALVE
ROLES OF EXPANSION VALVE
-Transform liquid refrigerant to two phase state of low temperature b, increase of pressure
-Adjust fluid quantity pf inside refrigerant of a system to make equilibrium.
SELECTION CRITERIA OF EXPANSION VALVE
-Supply ability with mass fluid quantity to maintrain given suction pressure of compressor and condensing temperature.
-Supply ability with stavle regrigerant fluid quantity to meet all given range of system operations.
STATE CHANGE OF EXPANSION DEVICE AND REFRIGERANT
※Expansion device always adjust Evaporator to exert maximum effect.
REFRIGERANT COMPRESSION PER VALVE OPENING
Overheat compression
-Expansion Valve is not opper fully.
-Shot of fluid quantity versus cooling power.
Saturation over dry surface compression.
-Appropriate opening of Expansion Valve.
Wet compression.
-Open Expansion Valve largely.
-Excessive fluid quantity versus cooling power.
-Possible Compressor damage.
Basic Principle of Expansion Valve
Forming small diameter origice tube like throttle valve to lower temperature and pressure of regfigerant gf vetter heat transfer.
Electronic Expansion Valve types
Thermoelectric type / Thermal type / Magnetic yape / Stepping motor type
Stepping motor type : Drive Valve by rotational power of stepping Motor.
Excellent dissolving ability,sice Valve opening is proportional to loaded Pulse quantity.
Strong points of Expansion Valve
1. Characteristics of detection part : applicable to temperature,pressure electric current adn others.
2. Possible to adjust Fluid Quantity Control freely by processing signal of MICOM.
3. High response characteristics.
4. Quick time cycle from opening to closing.
5. Applicable to wide range of refrigerating capacity variation.
6. Heat function of evaporator is enhanced due to correct and quick heat control.
7. Exact reverse operation is possible.
