节流阀[THROTTLE VALVE]

节流阀又称膨胀阀、调节阀，他是制冷系统不可缺少的四大重要设备之一。节流阀的作用是对冷凝器输出的高压液态制冷剂进行节流降压和调节流量。制冷剂液体经过节流阀节流降压后成为低温低压的汽液混合流体，经过氨液分离器分离掉无效的蒸汽后供往蒸发器中蒸发吸热。节流阀的型式很多，结构也各异，但是他们的基本原理均是使高压的液态制冷剂被迫通过一个适应系统流量的“小孔”，使其通过小孔时需要克服很大的流动阻力，因而使压力发生聚变，与此同时，一部分液体化为蒸汽，并从其本身吸取汽化潜热，因而使膨胀后的汽液混合流体变成低温低压状态。节流阀的阀芯为针形锥体或带缺口的锥体，阀杆的螺纹为细牙，当旋转手轮时，阀芯移动的距离不大，液体通过的面积也就很小，此时可以造成很大的局部阻力，高压液体通过小孔时消耗能量而降压。节流阀开启度的大小是根据蒸发器热负荷的变化而调定通常其开启度为手轮的八分之一至四分之一周，不能超过一周，否则开启度过大，即失去节流作用。

throttle valve as expansion valves, regulating valves, it is refrigeration system indispensable four one important equipment. throttle valve role is the export of high-pressure liquid coolant condensers to reduce and regulate the flow of relief. Coolant liquid after throttle valve expenditure of relief after a low-temperature low-voltage gas liquid mixed fluid, after separation into ammonia liquid separation devices for invalid after steam vaporizer, to evaporation endotherm. throttle valve many patterns, structures also vary, but their basic principles are that the high-pressure liquid coolant forced to adapt to the system through a flow "puncture wounds on the" make it through the puncture wounds on the need to overcome the considerable resistance movement, resulting in fusion pressure, and at the same time, some liquid into steam, and from its own lessons vaporization latent heat, thereby expanding the gas into liquid cryogenic fluid mixed low voltage state. throttle valve the Faxin for needle-shaped cone or belt gaps Cone, the thread for Fagan small teeth, when round-hand, the distance is Faxin mobile, liquid through the area is small, this can cause considerable local resistance, high pressure liquid through the puncture wounds on the consumption of energy and relief. throttle valve opened degrees is based on the size of the evaporator heat load changes that will be open for its usual hand for the eighth round to fourth week and not more than one week, otherwise spend big opening, lost spending.