Simulation of a Low-capacity Solar MSF Desalination Unit for a Steam Power Plant by Thermoflow Software

The current research focuses on the utilization of three waste water streams from a power plant located in southwestern Iran for desalination purposes and to prevent the waste of heat from the boiler blowdown stream while reducing carbon dioxide emissions by preheating the cooling water. Three different scenarios are simulated using the Thermoflow-GT master 23 software, considering the conditions of power plant. The optimal values for the top brine temperature (TBT) of cooling water and the mass flow rate of the hot steam are selected by sensitivity analysis. The premier scenario consists of eight stages, with five stages dedicated to heat recovery (HGS) and three stages for heat rejection section (HRS). The optimal value for the TBT of cooling water is determined to be 90℃, the produced freshwater capacity in the desalination unit is found to be 1.69 kg/s, and the gain output ratio (GOR) of the system is about 3.60. The proposed unit requires 0.47 and 10.15 kg/s of hot steam and cooling water, respectively and the overall heat transfer coefficient is 2069.2 W/m2 ℃. In addition, the feasibility of utilizing a solar farm to generate the necessary thermal energy for the system is being evaluated.