Research for the adjustable performance of the thermal vapor compressor in the MED-TVC system

As the expansion in the desalination industry, multiple-effect distillation (MED) with thermal vapour compression (TVC) system becomes more attractive than other thermal systems due to effectiveness, easier operation and maintenance, and good economic characteristics and is expected to take a considerable portion in the desalination field in the near future. The TVC is an essential part that governs the overall process in the MED-TVC system. The flow and heat transfer in the TVC is very complex due to the strong compressibility and supersonic turbulent flow of the stream. In this paper, based on gas-dynamic theory, a kind of semi-empirical calculation method of ejector, including calculation of the design point and variable operating condition of ejector, has been presented. The model gives the variation of the performance of the ejector as a function of the discharge pressure for different area values of throat and provides a foundation for the research for the performance of the adjustable ejector under variation condition. Furthermore, the necessity for the utilization of the adjustable TVC in the MED-TVC system and the performance for the adjustable TVC have been researched.