The operational performance of small-scale refrigeration systems is mainly decided by their capillary tubes outlet parameters, wherein an accurate determination of the pressure and vapour quality is a prerequisite. Experiments have been performed for a capillary tube (CT) with specified geometry consisting of a straight, a helical and a suction line heat exchanger (SLHX) section. The capillary tube is incorporated in a small refrigeration system operated with R600a. In addition, a model was developed to determine the steady-state operation of the capillary tubes (activated with R134a, R1234yf, R1234ze(E), R600, R600a, R152a and R513A refrigerants) and validated. The highest and lowest value of the vapour quality was discerned to be 0.3132 (for R1234yf) and 0.2124 (for R600), respectively. The relative errors between the experimental and model results for the CT outlet pressure and temperature were ranged from 1.16 to 5.35% and 0.12–0.81%, respectively. It is asserted that the present strategy may contribute towards the precise estimation of the pressure and vapour quality to customize the working performance of small scale refrigeration systems.

小型制冷系统的运行性能主要取决于其毛细管出口参数，其中压力和蒸汽质量的准确确定是前提条件。已经对毛细管 (CT) 进行了实验，该毛细管 (CT) 具有指定的几何形状，包括直管、螺旋管和吸入管热交换器 (SLHX) 部分。毛细管集成在一个使用 R600a 运行的小型制冷系统中。此外，还开发了一个模型来确定毛细管的稳态运行（使用 R134a、R1234yf、R1234ze(E)、R600、R600a、R152a 和 R513A 制冷剂激活）并进行验证。蒸汽质量的最高值和最低值分别为 0.3132（对于 R1234yf）和 0.2124（对于 R600）。CT 出口压力和温度的实验和模型结果之间的相对误差分别为 1.16 至 5.35% 和 0.12-0.81%。据称，本策略可能有助于精确估计压力和蒸汽质量，以定制小型制冷系统的工作性能。