چكيده به لاتين
Now a day, ejectors are used in various industries, such as seawater desalination, refrigeration systems, power plants, crude oil distillation, petrochemical processes, combined vacuum systems and air conditioning systems. In this study, all the dimensions of the ejector were calculated with MATLAB software using the thermodynamic equations governing water for the prevailing conditions in a multi-effect distillation desalination system with a thermal vapor compressor. Then, using the design of experiments method, the exergy efficiency of the ejector in different operating conditions in a certain interval of changes in the parameters of the ejector was obtained and its optimal value was determined. Afterwards, the ejector performance was studied numerically using Fluent software. The effect of adding auxiliary inlet on the overall performance of the ejector and the amount of entrainment ratio was studied. The optimal position, width and pressure of auxiliary inlet were also determined. Using the data obtained from numerical simulation, the design of experiments was performed to determine the effect of the parameters affecting the entrainment ratio and the maximum entrainment ratio was obtained.
The results showed that with increasing the inlet temperature of the primary fluid, the exergy efficiency first increases and then decreases. As the inlet pressure of the secondary fluid increases, so does the exergy efficiency. The maximum exergy efficiency is obtained when the inlet temperature of the primary fluid has its lowest value and at the same time the inlet pressure of the secondary fluid has its highest value. The maximum value of exergy efficiency was 76.6177%. By adding auxiliary inlet to the ejector, the entrainment ratio increases up to compared to conventional ejectors. It was found that the entrainment ratio increases first and then decreases with increasing primary fluid pressure. Also, as the nozzle output distance increases, the entrainment ratio first increases and then decreases. The maximum value of the suction ratio was 0.5269%.
