15 January 2001

Selected issues on CO2 as a working fluid in compression systems – Workshop Trondheim, Norway


CO2 has shown promising results as an alternative working fluid compared to the CFC’s, HFC’s and HCFC’s. CO2 provides an environmental friendly alternative in certain heat pump applications, in car air conditioning, and as secondary fluid in refrigeration systems. The physical and the thermodynamic properties of CO2 differ considerably from the more conventional working fluids and offer new possibibities as well as design challenges for systems and components.
To meet these challenges, five participants in the IEA Heat Pump programme, have joined forces in the collaborative project Annex 27: “Selected Issues on CO2 as Working Fluid in Compression Systems”. The aim of the Annex is to bring the CO2 technology closer to commercialisation by filling in some remaining gaps in the technology and to expand the knowledge of the use of this natural working fluid in heat pumps, air conditioning and refrigeration systems.

The prospects for the CO2-technology are positive. The first commercial pilot plant CO2 heat pump water heater was built and installed in Norway in 1999. In addition, Denso Corporation have in cooperation with Tokyo Electric Power Co (TEPCO) developed this year a commercial residential CO2 heat pump water heater in Japan.

Under IEA’s Annex 27, workshops are organised in co-operation with the IOEA Heat Pump Centre. The first of these workshops was held in Trondheim, Norway, and is documented in these proceedings. The workshop provided a broad overview of the latest developments, and stimulated an exchange of knowledge and views between industry parties, researchers and policy makers on the issue of the application of CO2. The results from the group work on selected issues are inlcuded in the proceedings. This information plays a vital role in setting the direction and scope for the future work under this Annex to ensure maximum impact and relevance. These proceedings are a useful information source for all those involved in this field to keep track of the latest developments in the CO2-technology.


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