Investigation of an alternative heat pump system

The depletion of fossil fuels in the world, especially in European countries, has led to the problem of heating, and over time, simultaneous solutions have been sought. Heat pumps have taken an important place among simultaneous solutions. CFC and HCFC refrigerants are widely used in these systems. These gases cause an increase in the global warming problem due to their greenhouse effects. As this problem is increasing day by day, the search for alternative fluids has increased. As a result of these searches, R744 applications have become widespread. Transcritical cycles, which realize heat transfer without condensation during the heat transfer of R744 in the gas phase to the environment, are also one of the important study topics today. In this study, the effect of electronic expansion valve (EGV) and gas refrigerant flow rate changes on the COP value of a transcritical heat pump system using R744 refrigerant is experimentally investigated. The system is an air-to-water heat pump and the temperatures of the water leaving the heat pump were evaluated during the experiments. Experimental studies were carried out in certain periods by changing the system parameters. By changing the electronic expansion valve opening percentage and water flow rate values, total heat transfer amount and power consumption values were recorded. These values were transferred to Excel and the COP results of 7 different experiments were compared as a result of the necessary calculations.