在空调或制冷系统中，一小部分润滑油从曲轴箱流出，进入工作液。与这种现象相关的两个主要问题是，这种油对系统中的压降有什么影响，以及在什么情况下，油会被报告回压缩机？这两个问题都与部件的尺寸和装置的效率有直接关系。关于第二个问题，曲轴箱中的机油不足最终会导致系统因缺少润滑剂而关闭。关于吸入和排出管线，ASHRAE赞助的研究项目已经解决了这个问题，该项目现已完成（RP 109）。最初的压降结果已在早期出版物中给出，而油输送结果已在早期出版物中总结。在前一篇论文中，对水平R-12和150 SS原油数据进行了关联。本文的目的是报告垂直结构和R形结构的压降结果- 22和300 SUS油。此外，将提供足够的文件，以便执业工程师使用相关性，并以表格形式给出设计数据。首先讨论实验设备，然后解释经验关系和相关结果。引文:阿什雷学报，第83卷，第2部分，哈利法克斯，北卡罗来纳州

In an air-conditioning or refrigeration system, a small percentage of the lubrication oil migrates out of the crankcase and into the working fluid. Two main concerns associated with this phenomenon are what is the effect of this oil on the pressure drop in the system and under what conditions is the oil reported back to the compressor? Both questions have direct relationship to the sizing of components and the efficiency of the unit. In relation to the second question, a deficiency of oil in the crankcase will eventually cause the system to shut down because of lack of lubricant.With regards to suction and discharge lines, this subject has been addressed by and ASHRAE-sponsored research project which has now been completed (RP 109). Initial pressure drop results have been presented and oil transport result summarized in earlier publications. In the former paper, horizontal R-12 and 150 SS oil data were correlated. It is the purpose of this paper to report pressure drop results for vertical configurations as well as for R-22 and 300 SUS oil. In addition, sufficient documentation will be presented so that the correlations can be used by practicing engineers and design data will be given in tabular form.The experimental facility will be discussed first, followed by an explanation of empirical relationship and correlated results.