Supersonic nozzle flow in the two-phase ejector as water refrigeration system by using waste heat

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.

In the near future the usage of waste heat in houses will be increased. The development of refrigeration system using waste heat is particularly needed for summer season consumptions. The ejector cycle can directly convert the thermal energy into the compression mechanical energy. Moreover, water which is one of the cleanest refrigerants can be used in the ejector cycle. As the steam ejector has been researched [1-3] as air conditioning system, the huge energy needed for large latent heat for water. We propose that the high-speed steam and water mixture, so-called two-phase flow, can be utilized instead of steam. It is theoretically shown that the heat need for this system will be reduced by the latent heat of hot water in two-phase flow, if the two-phase in the ejector flow has the same potential of acceleration and compression as steam. And the nozzle efficiencies for the two-phase flow of water are also obtained by the experiment.