M.Ing. / The refrigerant R22, which is currently used in hot water heat pumps, delivers a maximum hot water temperature of 60 to 65 °C. This temperature is adequate for domestic use, but low if compared to temperatures that can be delivered by fossil fuels and direct electric resistance systems. This limits the potential applications of hot water heat pumps. In this study two analytical design methodologies were developed that can be used to predict the performances of water-to-water heat pumps. The first design methodology is for a pure R22 heat pump and the second for a non-azeotropic refrigerant mixture of R22 and R142b. These design methodologies were used as tools together with three methods of comparison to determine the influence of a non-azeotropic refrigerant mixture (R22 mixed with R142b) on the performance of a hot water heat pump. It was found in certain cases that, depending on the concentrations, not only are increased hot water temperatures possible but also an improved heating capacity, an improvement in the coefficient of performance and a reduction in pressure ratio of the compressor.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:3404 |
| Date | 29 August 2012 |
| Creators | Smit, Floris Jakobus |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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