通过结合守恒方程，导出了一个特别适用于毛细管中fanno流动数值模拟的常微分方程（ODE）。以压力为自变量，可以更好地控制设计变量，避免阻塞流中的奇点。对于没有温度滑移的制冷剂，如纯制冷剂或共沸制冷剂混合物，如果给定饱和热力学性质，则可以很容易地集成单个ODE。对于非共沸制冷剂混合物（NARM），需要在温度滑动区进行迭代。作为迭代的替代程序，通过考虑热力学关系，导出了两个常微分方程组。 ODE系统不仅在数值上是有效的，而且揭示了关于扼流的重要物理。三元NARM R-407C的样本数值结果显示了所提出程序的性能。单元:SICitation:研讨会，ASHRAE交易，1998年，第104卷，第2部分，多伦多

An ordinary differential equation (ODE), particularly suitable for numerical simulations of fanno flows in capillary tubes, is derived by combining the conservation equations. Taking pressure as the independent variable, better control over design variables is achieved and the singularities involved in the choked flows can be avoided. For refrigerants without temperature glide, such as pure refrigerants or azeotropic refrigerant mixtures, the single ODE can be easily integrated if the saturation thermodynamic properties are given. For nonazeotropic refrigerant mixtures (NARMs), iteration in the temperature glide zone is required. As an alternative procedure for the iteration, a system of two ODEs is derived by taking thermodynamic relations into account. The system of ODE is not only in a numerically efficient form but also reveals important physics regarding choking. Sample numerical results for ternary NARM R-407C are presented to show the performance of the proposed procedures.Units: SI