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Investigation of the optimal intermediate water temperature in a combined r134a and transcritical CO2 heat pump for space heating
journal contribution
posted on 2023-05-19, 07:46 authored by Song, Y, Li, D, Cao, F, Xiaolin WangXiaolin WangIn this paper, the effect of intermediate water temperature on the performance of a combined R134a and transcritical CO2 heat pump was studied theoretically and experimentally. The mathematical model was first validated using experimental data and then applied to analyze the performance of the combined system. The results show that there exists an optimal intermediate water temperature (water inlet temperature at the gas cooler) at which the combined system has the highest COP. This optimal intermediate water temperature varies with the ambient air temperature. Furthermore, the effect of intermediate water temperature on individual R134a and transcritical CO2 subsystems was investigated.The results show that both heating capacity and power consumption in the R134a subsystem increase as the intermediate water temperature increases. However, power consumption in the CO2 system drops slightly, and heating capacity reaches an optimal value as the intermediate water temperature increases from 15 to 32 °C under ambient air temperatures ranging from −20 to 7 °C.
History
Publication title
International Journal of RefrigerationVolume
79Pagination
10-24ISSN
0140-7007Department/School
School of EngineeringPublisher
Elsevier Sci LtdPlace of publication
The Boulevard, Langford Lane, Kidlington, Oxford, England, Oxon, Ox5 1GbRights statement
© 2017 Elsevier Ltd and IIR. All rights reserved.Repository Status
- Restricted