A TVC system is used to desalinate seawater at 35 ^C with 42000 ppm salinity. The maximum allowable brine temperature is 100 ^C. The heat transfer coefficient for the evaporator and the two preheaters is constant and equal to 5.016 kW/m^ ^C. The specific heat transfer area is 109.46 m^ per (kg/s) of fresh water and the heat transfer area of the distillate preheater is 200 m^. The flow rates of the hot and cold stream in the preheaters are equal. The temperatures of the distillate and rejected brine flowing from the preheaters are 45 C and 40 ^C, respectively. Calculate the thermal performance ratio.