Accelerated screening methods for predicting lubricant performance in refrigerant compressors: Final report

摘要

The tribological characteristics of various lubricant/refrigerant mixtures have been experimentally investigated by means of a unique high pressure tribometer (HPT). In order to identify more effective bench testers for screening lubricants for compressors, a comparison is made between data obtained from the HPT, Four Ball and Falex(trademark) testers, and those obtained from accelerated component (compressor) tests. Part 1 of this study is geared toward a comparison between data obtained from a Falex specimen tester and those obtained by the HPT. The main purpose of this comparison was to determine if the controlled environment and the lower loads used with the HPT produce different rankings than those obtained from the Falex tests. The results obtained from the HPT gave a consistent ranking a different loads and speeds and this ranking did not always correlate with that obtained from the Falex tester. In Part 2, the HPT is used to approximately simulate specific critical contacts in compressors to determine the degree to which it could predict lubricant performance. A comparison is made between data obtained from component tests and those obtained from the HPT. For comparison purposes, each lubricant is also tested and ranked based on results obtained in an air environment with both the HPT and a Four Ball machine. Based on wear data, the rankings of the lubricants obtained from the various testers are compared to the lubricant rankings obtained from the component tests. Assuming that the component data are correct, this comparison shows that approximately a 65% accuracy is obtained by means of the HPT operating in a pressurized refrigerant environment and that this accuracy is essentially the same as the accuracy with the HPT operating in an air environment, the Falex tester and the Four Ball tester. (ERA citation 20:006113)