Energy characteristics of a two-evaporator refrigerator using a refrigerant mixture. Phase II. Project X01 7762. Final report
Thermodynamic analysis has shown that energy can be conserved in a two-evaporator refrigerator by applying a non-azeotropic mixture of refrigerants in place of a single refrigerant. The two major efforts are: (1) optimization of the distribution of heat-transfer area and of the mixture concentration, and (2) an experimental study to validate the analytical models. The mixture chosen was R12/R114. The optimization showed two local minima of energy consumption, one at 30% R114 and the other at 70% R114 by mass. While the 70% R114 mixture indicated power requirements about 1.4% less than the 30% R114 mixture, the vapor of the 30% R114 mixture is the denser of the two and requires lower compressor displacement. With respect to the distribution of heat-transfer area, the optimization indicated that the area of the low-temperature heat exchanger could be used better in the other heat exchangers. This finding would be viewed favorably from a manufacturing standpoint. The experimental studies consisted of a series of tests of various R12/R114 concentrations and confirmed the progressive change in temperatures of the boiling and condensing refrigerant. The tests were inconclusive in validating the energy conservation possibilities, but uncovered important practical considerations such as the influence of pressure drop in the heat exchangers and the performance of the compressor with the low vapor density that occurs at high R114 concentrations.
- Research Organization:
- Oak Ridge National Lab., TN (USA); Illinois Univ., Urbana (USA). Dept. of Mechanical and Industrial Engineering
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5082112
- Report Number(s):
- ORNL/Sub-81-7762/2; ON: DE82020488
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
REFRIGERANTS
PERFORMANCE TESTING
REFRIGERATORS
ENERGY EFFICIENCY
BOILING POINTS
COMPRESSORS
CONCENTRATION RATIO
DYNAMOMETERS
EVAPORATORS
EXPERIMENTAL DATA
FLOW RATE
HEAT EXCHANGERS
HEAT TRANSFER
MATHEMATICAL MODELS
MIXTURES
OPTIMIZATION
PRESSURE DEPENDENCE
TEMPERATURE DISTRIBUTION
THERMAL ANALYSIS
VALIDATION
DATA
DISPERSIONS
EFFICIENCY
ENERGY TRANSFER
FLUIDS
INFORMATION
MEASURING INSTRUMENTS
NUMERICAL DATA
PHYSICAL PROPERTIES
TESTING
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
WORKING FLUIDS
320100* - Energy Conservation
Consumption
& Utilization- Buildings