- Author
- Buschmeier, M. | Mulroy, W. | Didion, D. A.
- Title
- Initial Laboratory Evaluation of a Single Solution Circuit Cycle for Use With Nonazeotropic Refrigerants.
- Coporate
- Universitaet Hannover, West Germany National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Department of Energy, Oak Ridge, TN
- Report
- NISTIR 4406, October 1990, 46 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- air conditioning | capacity modulation | heat pumping | nonazeotropic refrigerants | refrigeration cycles | refrigerant mixtures | single solution circuit | vapor compression cycle
- Abstract
- Tests were conducted at the National Institute of Standards and Technology (formerly the National Bureau of Standards) to evaluate a single solution circuit cycle for use with nonazeotropic refrigerant mixtures. The single solution circuit cycle incorporates a liquid refrigerant pump in parallel with a compressor. This allows separate control of refrigerant compositon to match load and of refrigerant temperature change (glide) in the two-phase region to match the heat source or sink temperature glide. Load matching by composition shifting to match light loads to the extent possible with the tested mixture (R22/R11) was found to be an inefficient air conditioning mode control strategy. Nonlinearity of enthalpy vs. temperature in the two-phase region of the R22/R11 limited the efficiency gains possible by glide matching to a 19% improvement over pure R22. The cycle did function as intended, allowing glide matching over a wide composition change. It is felt that with a more linear refrigerant, substantial efficiency gains over the normal vapor compression cycle would be possible for applications in which the heat source and sink glides vary substantially with load.