Experimental evaluation of air-to-water propane heat pumps with 40kW heating capacity

Abstract: This thesis presents the experimental work on testing the seasonal performance of a 40 kW air-to-water propane heat pump, as a part of the research project Next Heat Pump Generation working with Natural fluids (NxtHPG) that has been carried out in ‘Applied thermodynamics and refrigeration Division’ in the department of Energy Technology, KTH. The thesis work involves three parts: preparation of the HP unit test rigs, experimental campaign and the evaluation of test results. In the first part, the set-up of the measurement device and necessary modifications to the heat pump unit as well as the test rigs have been completed to create an accurate measuring environmental for the experimental campaign. During the second stage, two series of experimental campaign have been done in the heating mode of the heat pump unit, and satisfactory results have been obtained in parts of the test conditions. Finally, the evaluation on the system performance as well as the behaviors of the components is discussed. The variation between experimental results and the simulation conducted by IMST-ART model is within reasonable range, proving that the heat pump unit has been working in good conditions. The compressor is proved to have been performing as manufacturer expected. However, some further investigations on the behaviors of the heat exchangers and expansion valve, such as superheat oscillation, are recommended be carried out in the future work. The completion of the rest of tests in which minus air temperature should be maintained and the ones with the desuperheater working should be done as well.