Process investigation of different locations of thermo-compressor suction in MED–TVC plants

The desalting of seawater has been a vital issue in several countries around the world in which water shortage is a serious problem. Through the process of designing desalination systems, with consideration of energy crisis, amount of energy consumption is a very important economical factor. In multi-effect distillation systems with thermal vapor compression (MED–TVC), thermo-compressor plays a main role in energy consumption. The geometry and operating conditions of thermo-compressor can have a significant influence on energy consumption. In this research, the influence of changing the suction position of thermo-compressor on the amount of energy consumption of the plant is analyzed. Results of the study showed that variation in suction pressure of thermo-compressor has considerable effects on the entrainment ratio. However, in order to have the maximum entrainment ratio and consequently reduce energy consumption, integration of MED–TVC with MED desalination must be optimized into the position of thermo-compressor suction. It was found that changing the suction location of thermo-compressor from the last effect to the middle effects or increasing the suction pressure has a valuable role in decreasing the energy consumption of the system. Results showed that the optimum value of compression ratio of thermo-compressor is between 2 and 2.5.

► Thermo-compressor suction location in the middle effects increases the suction load.
► System should be optimized to find the best integration of MED-TVC and MED.
► GOR would be maximum when TVC compression ratio is between 2 and 2.5.