Selection and Chemical Testing of Fluids for High Temperature Heat Pumps - Part 3. Work Fluid/Lubricant Combinations

摘要

The development of high temperature heat pumps has identified the short-comings of conventional lubricants and work fluids. At elevated operating temperatures, the physical and chemical requirements of both these types of fluid are more rigorous than in existing systems. Because of the many possible combinations of work fluids and lubricants, it was necessary to design a simulator which would reproduce as nearly as possible the chemical environment within the working system. This simulator, which also allowed the study of time accelerated chemical reactions of fluids in the presence of catalytic surfaces, is described in detail. The course of chemical breakdown for several potential work fluids with both mineral oils and synthetic lubricants is illustrated. The results obtained demonstrate the effectiveness of this rapid test technique in sorting different fluid systems in order of chemical stability.