The work of the thesis is to present a comparison of three different two-phase ejector refrigeration cycles as well as a comparison to an expansion valve refrigeration cycle with two evaporation temperatures. An analytical comparison of the theoretical COPs of the ejector cycles shall be presented. Based on results of numerical simulations, appropriate modifications of the existing ejector test facility shall be carried out. The student will make the design of the modifications. Finally a set of experiments shall be planned and performed for different options of the ejector cycle (with vs. without vapor liquid separator, single vs. dual evaporator, diffuser outlet split vs. condenser outlet split).