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Author
Devotta, S. | Padalkar, A. S. | Sane, N. K. | Domanski, P. A. | Sawant, N. N.
Title
Simulation of Heat Exchangers of a Window Air Conditioner Retrofitted With R-407C.
Coporate
National Chemical Laboratory, Pune, India Walchand College of Engineering, Sangli, India National Institute of Standards and Technology, Gaithersburg, MD
Report
IRC0048,
Book or Conf
International Congress of Refrigeration, 21st IIR. Proceedings. August 17-22, 2003, Washington, DC, 1-8 p., 2003
Keywords
heat exchanger | air conditioning | refrigerants | evaporator | zeotropic mixtures | thermodynamics | simulation | temperature profiles | pressure drop | air temperature
Identifiers
condenser; rated capacity test conditions; indoor room conditions; outdoor room conditions; refrigerant condtions at the evaporator outlet; refrigerant conditions at the condenser inlet; comparison between experimental and simulated outlet air temperatures; evaporator outlet air temperature; condenser outlet air temperature
Abstract
This paper presents simulation results for the heat exchangers of an HCFC-22 window air conditioner retrofitted with R-407C. The test conditions are per the Indian Standard IS 1391 (1992) for unitary air conditioners. The simulation was carried out using EVAP-COND, a heat exchanger model developed by NIST. A typical Indian window air conditioner of capacity 5.13 kW (1.5 TR) was selected for the study. The performance of the heat exchangers with R-407C is compared with the baseline performance with HCFC-22. The simulation results are validated by comparing to experimental data for a window air conditioner retrofitted with R-407C. The assessment parameters are temperatures of refrigerant and air, and refrigerant pressures and pressure drops. The simulated evaporator capacity with R-407C is lower by 3.3% for the lower outdoor conditions and 6% lower for the higher outdoor conditions with respect to HCFC-22. R-407C has 6.1% lower condenser capacity for the lower outdoor conditions and 10.6% lower for the higher outdoor conditions with respect to HCFC-22. The simulated evaporator capacities are within ± 3% of the experimentally measured cooling capacities for both refrigerants. The exit temperatures of R-407C are lower by 1.9 °C to 5.2 °C in the condenser and are higher by 3.2 °C to 3.8 °C in the evaporator as compared to HCFC-22. The evaporating pressures of R-407C are higher by 4.5% to 5.3% as compared to HCFC-22. The condensing pressures of R-407C are higher by 10.3% to 14.1% as compared to HCFC-22. The pressure drop of R-407C is lower in both the evaporator and the condenser as compared to HCFC-22. The outlet temperatures of air for HCFC-22 and R-407C in both heat exchangers are nearly the same.