- Author
- Kauffeld, M. | Mulroy, W. | McLinden, M. O. | Didion, D. A.
- Title
- Experimental Evaluation of Two Nonazeotropic Refrigerant Mixtures in a Water-to-Water, Breadboard Heat Pump.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Department of Energy, Washington, DC
- Report
- NISTIR 90-4290, June 1990, 62 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- air conditioning | heat pumps | intracycle heat exchange | nonazeotropic refrigerants | refrigerant mixtures | refrigerants | refrigeration
- Abstract
- An experimental, water-to-water, breadboard heat pump (that is one designed to be easily reconfigured) was constructed for comparison of pure R22 to the refigerant mixtures R22/R114 and R13/R12. Three evaporator configurations were extensively studied. In all cases the best mixture outperformed R22. The best efficiency with R22/R114 was 32% higher and with R13/R12 was 16% higher than the best eficiency measured with R22. Other observations were, first, mixtures can take advantage of heat exchanger efficiency that, in a gliding temperature application, a pure refrigerant is incapable of utilizing. Secondly, heat exchange between the condensed and evaporating refrigerant is beneficial to some mixed refrigerants. Finally, mixtures exhibit nonlinearity of enthalpy versus temperature in the two phase region which has significant impact on both heat exchanger and cycle design.