从空调/热泵的高压侧（高压侧）到低压侧（低压侧）的制冷剂节流可通过多种装置完成，最常见的是恒温膨胀阀、毛细管和塞孔。本研究的重点是绝热毛细管，并针对详细的数据，这些数据将导致根据液体管线压力、流速、入口过冷度和蒸发器压力选择毛细管的方法。使用控制过冷度、冷凝器和蒸发器压力的测试回路测试了几种毛细管长度和直径组合。 还进行了测试，以测量分布压降，并确定缠绕对毛细管限制特性的影响。卷取可以使压降增加约5%，同时发现分配器的损失系数略高于再入流的损失系数。关键词:毛细管，管，R22，制冷剂，测试，流体流动，节流，空调，热泵，过冷，压降。引用:研讨会论文，佐治亚州亚特兰大，1990年

The throttling of refrigerant from the high-pressure side (high side) to the low-pressure side (low side) of an air conditioner/heat pump may be accomplished by a variety of devices, the most common being thermostatic expansion valves, capillary tubes, and plug orifices. This study focuses on the adiabatic capillary tube, and is directed toward detailed data that would lead to means of selecting capillary tubes given the liquid line pressure, flow rate, and degree of inlet subcooling and evaporator pressure. Several capillary length and diameter combinations were tested using a test loop that provided control of the subcooling, and condenser and evaporator pressures. Tests were also performed to measure the distribution pressure drops and to determine the effects of coiling on the restriction characteristics of the capillary tube. Coiling was noted to increase the pressure drops by about 5%, while the loss factor for the distributors was found to be slightly higher than that for re-entrant flows.KEYWORDS: capillary tubes, tubes, R22, refrigerants, testing, fluid flow, throttling, air conditioning, heat pumps, subcooling, pressure drop.