Influence of the degree of superheating on the performance of a R134a condenser by means of experimental and numerical studies.
Abstract In this investigation the influence of the degree of superheating at the inlet of a R134a condenser on its performance is studied. The degree of superheating is controlled by liquid injection from the condenser outlet by a membrane pump. The physical phenomena of influence are a reduction in the mean temperature difference and an increment in the overall heat transfer coefficient. An experimental rig has been built and a number of operating conditions tested as a function of the compressor capacity, evaporator power and the degree of inlet superheating. A numerical model has been developed for the experimental setup, the result of which has been compared with the experimental data. Additionally, the model has been used to understand the evolution of the heat transfer inside the condenser. It has been concluded that the overall condenser efficiency may slightly increase at high evaporator loads and high compressor capacities.