随着目前住宅、商业和工业部门节能措施的推进，制冷剂系统已成为大量研究的对象。设备制造商和终端用户正在寻求通过提高单个部件的效率来降低空调机组和其他能量传输系统的运行成本的方法。正如系统建模师所知，单个部件效率的变化将导致整个机组寻求新的平衡运行状态点，需要一整套平衡计算来分析运行；在环境范围内。最简单的制冷剂系统使用两个热交换器、一个压缩装置和一个节流机构。 最常用的节流机构是恒温膨胀阀或毛细管。这两种装置导致了截然不同的系统行为特征，长期以来，对节流装置中制冷剂的流动进行建模一直是系统分析的关键部分。本文的目的是提出一种数学迭代方法来模拟毛细管中从液体或两相入口到液体或两相出口的闪蒸流动，并显示必须收敛的变量，以生成制冷剂系统的平衡计算。考虑到文献中提供的大量压降关系，选择一个最适合毛细管流动的模型并非易事。 由于在闭环分析的所有方面都是完整的，因此对两相关联进行了详尽的搜索，从而得出本文所示的选择。如果这个方法看起来很简单，那就是。但是，将一种方法与一组遵循公认的ASHRAE曲线的关系相匹配是本文的贡献。研究人员早就知道，毛细管减压很难建模，因为诸如管螺旋曲率和管方向等因素可能会影响流动参数。本文对这些参数的通用建模没有给出明确的解决方案，但提供了一种方法，在将计算机预测与实验数据相匹配时，可以考虑适当的因素。 引用:俄亥俄州辛辛那提市ASHRAE学报第87卷第2部分

With the present thrust of energy conservation measures in residential, commercial, and industrial sectors, refrigerant systems have been the object of considerable study. Manufacturers of equipment as well as end users are seeking ways of reducing the operating cost of air-conditioning units and other energy transfer systems by increasing the efficiency of individual components. As the system modeler knows, a change in efficiency of a single component will cause the entire unit to seek a new equilibrium operating statepoint requiring a complete set of balance calculations to analyze operation; over the ambient range. Refrigerant systems in their simplest form use two heat exchangers, a compression device, and a throttling mechanism. The throttling mechanisms most commonly used are thermostatic expansion valves or capillary tubes. These two devices cause radically different system behavior characteristics and modeling the flow of refrigerant in-throttling devices has long been a critical part of systems analysis. The purpose of this paper is to present a mathematical, iterative approach to modeling, the flashing flow in capillary tubes from either liquid or two-phase inlet to either liquid or two-phase outlet, and show the variables which must be converged to generate balance calculations for refrigerant systems.Considering the abundance of pressure drop relationships available in the literature, choosing one which best models capillary flow is no mean task. An exhaustive search for two-phase correlations resulted in the choice shown in this paper because of its completeness-in all aspects of closed loop analysis. If the-method-appears simple, it is. But matching a methodology to a set ofrelationships which follow the well accepted ASHRAE curves is the contributionof this paper. As researchers have long known, capillary tube depressurizationis difficult to model because such factors as tube spiral curvature and tubeorientation may effect the flow parameters. This paper affords no clear-cutsolutions to universal modeling of these parameters, but offers a method whereappropriate factors may be considered in matching computer predictions to experimentaldata.