University Of Tasmania

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Theoretical and experimental investigation of a combined R134a and transcritical CO2 heat pump for space heating

journal contribution
posted on 2023-05-19, 00:49 authored by Yang, D, Song, Y, Cao, F, Jin, L, Xiaolin WangXiaolin Wang
In this paper, a novel combined R134a and transcritical CO2 system was studied theoretically and experimentally for space heating. Experimental results showed that the ambient and space heating temperatures substantially affected the system performance. At the heating requirement with 50 °C in feed water temperature and 70 °C in supply water temperature, the heating capacity and coefficient of performance (COP) increased by 32.6% and 18.2%, respectively, as the ambient temperature increased from −20 °C to 0 °C. The system COP increased by up to 15% at fixed ambient condition as the feed and supply water temperatures decreased from 50 °C/70 °C to 40 °C/50 °C. A mathematical model was also developed and validated using experimental data. The model was used to investigate the performance improvement of the combined system in comparison to the standard transcritical CO2 system. The comparison results showed that the combined system improved the COP by up to 22%.


Publication title

International Journal of Refrigeration








School of Engineering


Elsevier Ltd.

Place of publication

United Kingdom

Rights statement

Copyright 2016 Elsevier Ltd and IIR

Repository Status

  • Restricted

Socio-economic Objectives

Residential energy efficiency