Investigating the effect of effective parameters on the optimization of zero liquid discharge system

Abstract

Abstract Due to the critical water situation in the world and the need for freshwater, the use of desalination systems is very common. One of the main problems of using such devices is the production of a high-concentration brine stream, which causes environmental problems. Therefore, the need to use systems that reduce the level of salt water to zero (zero liquid discharge [ZLD]) is felt more than ever. The biggest challenge for the widespread implementation of thermal ZLD systems is its high energy consumption and, as a result, high cost. Therefore, we seek to find effective parameters to reduce the heat transfer surface and energy consumption to make it economic. In this research, it is possible to mention the inlet and outlet salinity, Overall heat transfer coefficients, evaporator temperature and cooling water temperature among the parameters investigated in the evaporator and the parameters investigated in the crystallizer include the operating temperature of the crystallizer and steam temperature in the heat exchanger. The results showed that the most optimal state (the lowest total heat transfer surface and energy consumption) of the ZLD system in the overall heat transfer coefficient in the evaporator is equal to 4 kW/m2 °C. The total heat transfer surface is equal to 2258.78 m2 and energy consumption is 2111.5 kW.