Investigations of heat and momentum transfer in two-phase injector operating with isobutane

Abstract Paper deals with experimental investigations of two-phase vapour-liquid injector in application to refrigeration systems. The selected experimental results for the injector for the case of isobutane as a working fluid were presented. According to the authors knowledge there are no previous investigations of the two-phase injectors for the other fluids than steam and water. Thermal efficiency and compression efficiency of the tested injector were presented. Experiments show that the subcooling of the entrained liquid has large impact on operation of the injector as well as momentum transfer. Large database of own experimental results allowed for development of the correlations for velocity coefficients for the components of the injector. It was demonstrated that these coefficients should not be treated as a constant quantities as it is commonly assumed in literature. The dimensionless relationship describing condensation heat transfer in the mixing chamber was proposed.