Thermodynamic modeling of vacuum generator utilization for cooling cycles using low-grade thermal sources

Some heat sources, such as biomass, solar heat, and other waste heat, have the potential to be reused. Some air conditioners usually require electrical energy to meet cooling needs in tropical climates. In this type of air conditioner, electrical energy is needed to drive the compressor in the cooling system. Implementing a cooling system using a solar heat source or other low heat sources to evaporate the working fluid as an ejector driving medium could reduce electrical energy consumption. This system can replace the compressor function in conventional air conditioning systems. This study performs a thermodynamic analysis of the ejector performance for the refrigeration cycle. Refrigerant R141b is used as the working fluid. It has low-pressure characteristics and makes a low pump head ideal for use in refrigeration cycles. Simulations were carried out using the saturation temperature parameter of the vapor generator at 80-100°C and the saturation temperature of the condenser at the same temperature at 40°C. It was found that applying the ejector in the refrigeration cycle can reduce electricity consumption by up to 40.78 % compared to conventional air conditioning systems but from the overall comparison, the results have not been fully able to reduce the use of electrical energy.