Properties and Cycle Performance of Refrigerant Blends Operating Near and Above the Refrigerant Critical Point, Task 1: Refrigerant Properties
The main goal of this project was to investigate and compare the performance of an R410A air conditioner to that of an R22 air conditioner, with specific interest in performance at high ambient temperatures at which the condenser of the R410A system may be operating above the refrigerant's critical point. Part 1 of this project consisted of measuring thermodynamic properties R125, R410A and R507A, measuring viscosity and thermal conductivity of R410A and R507A and comparing data to mixture models in NIST REFPROP database. For R125, isochoric (constant volume) heat capacity was measured over a temperature range of 305 to 397 K (32 to 124 C) at pressures up to 20 MPa. For R410A, isochoric heat capacity was measured along 8 isochores with a temperature range of 303 to 397 K (30 to 124 C) at pressures up to 18 MPa. Pressure-density-temperature was also measured along 14 isochores over a temperature range of 200 to 400 K (-73 to 127 C) at pressures up to 35 MPa and thermal conductivity along 6 isotherms over a temperature range of 301 to 404 K (28 to 131 C) with pressures to 38 MPa. For R507A, viscosity was measured along 5 isotherms over a temperature range of 301 to 421 K (28 to 148 C) at pressures up to 83 MPa and thermal conductivity along 6 isotherms over a temperature range of 301 to 404 K (28 to 131 C) with pressures to 38 MPa. Mixture models were developed to calculate the thermodynamic properties of HFC refrigerant mixtures containing R32, R125, R134a and/or R125. The form of the model is the same for all the blends considered, but blend-specific mixing functions are required for the blends R32/125 (R410 blends) and R32/134a (a constituent binary of R407 blends). The systems R125/134a, R125/143a, R134a/143a, and R134a/152a share a common, generalized mixing function. The new equation of state for R125 is believed to be the most accurate and comprehensive formulation of the properties for that fluid. Likewise, the mixture model developed in this work is the latest state-of-the-art for thermodynamic properties of HFC refrigerant blends. These models were incorporated into version 7 of NIST REFPROP database.
- Research Organization:
- Air-Conditioning and Refrigeration Technology Institute (US)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EE) (US)
- DOE Contract Number:
- FC05-99OR22674
- OSTI ID:
- 808634
- Report Number(s):
- DOE/OR22674/605-50010-01-Pt1; arti-21cr/605-50010-01-Pt1; TRN: US200308%%83
- Resource Relation:
- Other Information: PBD: 30 Aug 2002
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
AIR CONDITIONERS
AMBIENT TEMPERATURE
ISOTHERMS
MIXTURES
PERFORMANCE
REFRIGERANTS
SPECIFIC HEAT
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
VISCOSITY
REFRIGERANT
TRANSCRITICAL
EVAP-COND
REFPROP
AIR CONDITIONER
EER
CAPACITY
R125
R-125
R410A
R-410A
R507A
R-507A
THERMOPHYSICAL
THERMODYNAMIC
VISOCITY
CONDUCTIVITY