DANFOSS thermal expansion valve
- Shanghai Zhongyi Ice Cream Equipment Co., Ltd.
- product brand:DANFOSS
- Messestand Nr.：E2A39
- product specification:
- product category:Refrigeration Equipment-Refrigeration systems and plants-Chillers, liquid
- product introduction:Expansion valve structure and principle of work 1 ROLE OF THERMAL EXPANSION VALVE: Thermal expansion valve installed in the evaporator inlet, often referred to as expansion valve, there are two main functions: 1) throttle function: High temperature and high pressure liquid refrigerant through the throttle hole of expansion valve throttle, become low temperature and low pressure of the fog-like hydraulic refrigerant, for the refrigerant evaporation create conditions; 2) control refrigerant flow: into the evaporator of the liquid refrigerant, after the evaporator, the refrigerant from the liquid evaporation into the gas, absorption of heat, reduce the temperature of the car. The expansion valve controls the flow rate of the refrigerant to ensure that the outlet of the evaporator is completely gaseous refrigerant. If the flow rate is too large, the outlet contains liquid refrigerant, which may enter the compressor to produce liquid shock; if the flow rate of the refrigerant is too small, evaporates ahead of time, resulting in insufficient refrigeration; 2 types of Thermal Expansion Valve: Thermal expansion valve in accordance with the balance of different types, sub-internal balance and external balance; External Balance Thermal Expansion Valve F and h type two structural types. 1) structure and working principle of internal balanced expansion valve: Structure Diagram of internal balanced f-type thermal expansion valve. The bag is filled with refrigerant and placed on the outlet pipe of the evaporator. The bag and the upper part of the film are connected by capillaries to feel the temperature of the refrigerant at the outlet of the evaporator. If the air conditioning load increases, the hydraulic refrigerant evaporates ahead of time in the evaporator, then the evaporator outlet refrigerant temperature will rise, the pressure on the diaphragm increases, pushes the valve stem to cause the expansion valve opening degree to increase, enters in the evaporator the refrigerant flux to increase, the refrigeration quantity; if the air conditioning load reduces, then the evaporator outlet refrigerant temperature reduces, by the same principle causes the valve opening degree to reduce, thus controls the refrigerant flux. 2) structure and working principle of External Balance Expansion Valve: the principle of external balance expansion valve and internal balance expansion valve are basically the same, the difference is: under the Diaphragm of internal balance expansion valve, the inlet pressure of evaporator is felt; under the Diaphragm of external balance expansion valve, the outlet pressure of evaporator is felt. 3) H type expansion valve h type thermal expansion valve has four connections to the refrigeration system, two of which are the same as ordinary thermal expansion valves, one for the reservoir dryer and one for the evaporator inlet; the other two connections, one for the evaporator outlet and one for the compressor inlet. The temperature sensor is directly in the refrigerant stream at the evaporator outlet. The expansion valve has the advantages of high adjusting sensitivity, compact structure, anti-vibration and reliability due to the elimination of the temperature-sensitive package, capillary tube and external balance nozzle in the f-type thermal expansion valve. 1 self-filtering Dryer 2 to evaporator 3 to evaporator 4 to compressor 5 measuring Hole 6 ball 7 Spring 8 movable foot 9 refrigerant 10 film pressure compensation 11 metal film 12 temperature sensing element
