Capillary is the simplest throttle mechanism in the water cooler. Daily use of refrigerators, air conditioner, small wet reduction machine ammonia cooler small freon refrigeration equipment, the condensing temperature and evaporating temperature change is not obvious and cooling capacity is small, in order to simplify the structure, usually with a capillary as the throttling mechanism.
The so-called capillary, is a very small diameter of the purple copper tube. Fluid flow through the pipeline to customer service pipeline resistance, with a certain pressure drop, and the smaller the diameter, the longer the pipe, the greater the pressure drop. So when the refrigerant flows through the capillary tube, the capillary plays the role of throttling expansion. When the inner diameter and length of the capillary tube and the pressure difference at both ends of the capillary tube, the refrigerant liquid flow rate of the capillary tube is also certain. As a result, the capillary tube with appropriate diameter and length can be chosen as the throttling mechanism to realize the purpose of reducing the pressure and controlling the flow rate of the refrigerant.
Capillary as the throttle body, with has the advantages of simple structure, convenient manufacture, cheap price and easy failure and other advantages, and after the compressor stops working, the pressure of condenser and evaporator can achieve automatic balance, reduce the re start the motor load. But the inner diameter and the length of the capillary, at both ends of the capillary pressure difference remained constant, refrigerant flow can not be regulated, so the poor regulating performance, supplying liquid volume, not with the variation of the operating condition of the adjusted, so the capillary only for little evaporation temperature changes in noncardiac and load is relatively stable and the occasion.