Simulation Study for An Adjustable Ejector Used in Solar Air-Conditioning Systems

This paper explores the potential of ejector refrigeration systems as sustainable cooling solutions driven by low-grade energy sources like waste heat or solar collectors. The focus is on adjustable ejectors, vital for enhancing efficiency in these systems. Simulations examine their performance within solar air-conditioning setups. In typical ejector refrigeration systems, a generator, condenser, evaporator, ejector, pump, and expansion valve form the core components. The generator initiates the refrigeration process using low-grade energy, with high-pressure vapor entering the ejector nozzle, inducing the release of low-pressure vapor from the evaporator. Mixing and pressure recovery within the ejector are key to optimizing system performance. Using the k–
$\varepsilon$
turbulence model in CFD simulation, the study conducts 2D steady flow analysis under varying conditions, including generator temperature, back pressure, and evaporator temperature, with R134a as the working fluid. Validation experiments confirm results accuracy, particularly regarding the entrainment ratio, the optimum
$Er$
value obtained from the simulation is 1.2, highlighting the significance of generator temperature and back pressure in enhancing coefficient of performance (COP), among other findings.