Thermodynamic Analyses Of Ejector Used In Organic Rankine Cycle

Due to the lower temperature difference between the low-temperature heat source temperature (as defined below 200℃) and the ambient temperature, the power generation capacity of low-temperature heat source is low. Therefore, to improve the capacity and efficiency of power generation by utilizing the low-temperature heat source is the crucial problem in the research and application of low temperature heat source for power generation.In the Organic Rankine Cycle with ejector (EORC), an ejector was added to the Organic Rankine Cycle (ORC) to reduce the expander back pressure, improve the expander output capacity, and improve the generation capacity of low temperature heat source. As the key component in EORC, the emphasis of ejector was to improve the entrainment ratio, reduce the Secondary fluid’s pressure, design ejector rationally, and make thermodynamic performance optimization of ejector.Based on the classical theory of ejector, the optimization procedures of the entrainment ratio and the Secondary fluid’s pressure were developed on the MATLAB platform, and also the calculation procedures of the entrainment ratio and the Secondary fluid’s pressure of ejector which geometrical dimensions were given. The structure and design of ejector were involved, which was used in EORC with R600 as working fluid. For certain operating conditions, the optimizations of the maximum of entrainment coefficient and the minimum of the Secondary fluid’s pressure were done; and also the calculations of the entrainment ratio and the Secondary fluid’s pressure of ejector which geometrical dimensions were given. The ejector’s performance was analyzed via the performance evaluation indexes: entrainment ratio, the Secondary fluid’s pressure, and injection efficiency.The experiments of ejector’s performance were carried out in the EORC’s experiments.