Performance of a residential heat pump operating with a non-azeotropic binary refrigerant mixture - an interim report. [R22 vs non-azeotropic binary mixture of R13B1 and R152a]

Technical Report · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5743762

Didion, D; Mulroy, W

This report presents results of laboratory measurement of the performance change of a substantially unmodified residential heat pump designed for R22 when charged with a non-azeotropic, binary mixture of R13B1 and R152a. Results are presented for various sizes of fixed expansion devices. The effect of gliding temperature in the saturation zone was found to be small. The effect of composition shift by flash distillation in the accumulator was found to measurably improve low temperature heating performance. There appears to be an inherent trade-off when operating an unmodified heat pump with mixtures so as to increase capacity at lower temperatures. This trade-off is that as the evaporator pressure decreases and refrigerant begins to flood through to the accumulator and thus allowing the composition shift to occur, the subcooling on the high pressure side also decreases causing a decrease in the available latent enthalpy difference. A possible solution to this problem might be to increase the amount of initial charge. This would cause on increase in head pressures which could be a problem in the cooling mode. A possible solution to this excessive head pressure problem would be to incorporate a receiver in the system in the branch line just ahead of the expansion device for the outdoor coil. Thus, when this coil is acting as an evaporator (i.e., heating mode) the stored refrigerant would be released into the circulating system allowing for more composition shift to occur. Such a solution will be pursued as one of the items of study during the next phase of this project. 9 refs., 11 figs., 1 tab.

• Research Organization: National Bureau of Standards, Washington, DC (USA). Building Equipment Div.
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5743762
• Report Number(s): CONF-841231-16; ON: DE85005245
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320100* -- Energy Conservation
Consumption
& Utilization-- Buildings
AIR SOURCE HEAT PUMPS
BUILDINGS
CAPACITY
COMPUTERIZED SIMULATION
DATA
EFFICIENCY
FLUIDS
HEAT PUMPS
INFORMATION
NUMERICAL DATA
RELIABILITY
RESIDENTIAL BUILDINGS
SIMULATION
WORKING FLUIDS