中文摘要：

变径毛细管是一种用于家用热泵的低成本节流装置,其非对称结构可以实现正反两个流向的流量不同,从而可以满足热泵系统制冷和制热所需的流量。为了实现变径毛细管工程设计,开发了变径毛细管流量的关联式。通过构建变径毛细管等效管径和等效管长计算公式并代入等径毛细管关联式,得到了变径毛细管流量的关联式的公式形式;通过数值计算模型产生用于拟合关联式系数的数据源。开发的变径毛细管流量关联式可计算变径毛细管正向和反向的制冷剂流量以及传统的等径毛细管的流量。开发关联式能很好地预测变径毛细管在不同工况下制冷剂流量的变化趋势,预测93%实验数据点的精度在10%以内。

英文摘要：

A varying diameter capillary tube is a low cost throttling device for residential heat pump systems. The asymmetry structure of the varying diameter capillary tube results that forward flow resistance differs from backward one, and then the specific flow rates for cooling and heating mode can be achieved simultaneously. In order to size the capillary tube practically, a dimensionless correlation for predicting mass flow rate through varying diameter capillary tubes is proposed. The formula of equivalent tube diameter and tube length is constructed, and is introduced into an existing correlation for predicting mass flow rate through smooth capillary tube; a numerical model was developed based on the physical equations, and it is used to generate data source for curve fitting the coefficients in the proposed correlation. The proposed correlation can predict the measured mass flow rate through varying diameter capillary tube under various conditions, and it predicted approximately 93% of the measured mass flow rates within a deviation of ±10%.