Bir soğutma sistemindeki ejektörün sayısal analizi

Nowadays, environmentally-friendly solutions are being investigated instead of using fossil fuel and electrical energy systems, depending on the increasing energy consumption. Therefore, many studies have been carried out on a heat-driven ejector refrigeration cycle using waste heat or renewable energy sources as an alternative to the conventional refrigeration cycle. In this thesis study, the performance of different refrigerants for two geometric parameters was evaluated under the selected operating condition in numerical modeling of the ejector used in the heat-driven ejector refrigeration cycle. In numerical analyses, R1234yf, and R1234ze(E) having low Global Warming Potential value from Hydrofluoroolefin, and R1234a which will be excluded due to the high Global Warming Potential value were used as the refrigerant. Computational Fluid Dynamics method is used for numerical modeling of the ejector by using ANSYS Fluent, a commercial software. In addition, the thermophysical properties of refrigerants were obtained using REFPROP v9.1 database. Entrainment ratio, one of the most important performance criteria for the ejector, was determined by Computational Fluid Dynamics analysis using the ejector geometry selected as a reference from the literature. In addition to the entrainment ratio, the flow structures were discussed in detail using axial Mach Number distributions, Mach Number contours, and shadowgraphs in the mixing section of the ejector. In this way, it will contribute to previous numerical modeling studies in the literature and guide future studies for more realistic performance improvement values.