Performance optimization of CO2 heat pump water heater
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
A preliminary analysis was conducted to analyze the performance of a heat pump water heater (HPWH) that uses CO2 as the refrigerant. A model to predict the performance was developed and calibrated based on the experimental data for an existing HPWH using a CO2 refrigerant. The calibrated model was then used to run a parametric analysis in which factors such as water supply temperature, water circulation rate, tank stratification, and condenser configuration were considered. The performance of a commercial CO2 system was compared with that of a similar system using R-134a as the refrigerant. It was found that CO2 HPWH performance was comparable to that of an R-134a HPWH, more so for a separated gas cooler configuration. For comparable performance, the compressor size and the tube-in-tube heat exchanger (condenser/gas cooler) size were compared for CO2- and R-134a-based systems. Finally, the impact of the water circulation rate on the water temperature stratification in the tank, an essential requirement for higher performance for CO2 HPWH systems was also investigated.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1414698
- Alternate ID(s):
- OSTI ID: 1549396
- Journal Information:
- International Journal of Refrigeration, Vol. 85, Issue C; ISSN 0140-7007
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Comparison of Transcritical CO2 and Conventional Refrigerant Heat Pump Water Heaters for Domestic Applications
|
journal | February 2019 |
Similar Records
Max Tech Efficiency Electric HPWH with low-GWP Halogenated Refrigerant
Development of HPWH System Model, Using All Microchannel Heat Exchangers