Application of the Stirling cycle for environmentally compatible cooling - systems analysis

Status

completed

Summary

There is an increasing demand of cooling capacity in the near ambient temperature range (between -50 and +20°C): air conditioning, cooling, freezing, and shock-freezing. The use of state-of-the-art cooling-systems (vapour compression coolers) may cause environmental problems (e.g. ozone depletion, global warming), because of the emission of refrigerants used in these systems.

A possibility to avoid these problems is the use of cooling systems not relying on refrigerants as working fluids, for example Stirling cooling systems. For the four ambient temperature ranges the Stirling cooling technology was compared to the state-of-the-art technology regarding environmental, technical and economical effects. It was shown that the best chances for Stirling cooling technology are at temperatures less than about -30°C, i.e. for freezing and shock-freezing applications.

A case study for such an application showed an energy demand of the Stirling system which is about 40% lower compared to vapour compression systems. In view of the development of Stirling coolers in cooperation with industry, a survey was carried out. One interested company was found. As a next step a market analysis in the field of freezing and shock freezing should be performed, followed by a business plan for the development of Stirling coolers in cooperation with industry.