Solution Method of the Detailed MEE Model The developed model contains a large number of highly non-linear algebraic equations. The equations are solved by a modified fixed point iteration technique developed by El-Dessouky and Bingulac, 1996. The method is simple, but yet powerful and has proved to have a rapid convergence rate. The solution process starts with setting values of system parameters, which include salinity of intake seawater and rejected brine, temperature of intake seawater, temperature of rejected cooling seawater, and boiling temperature in effect n, tube length and diameter, vapor and brine velocities inside the tubes, evaporator area (constant in all effects), and area of preheaters in effects 2 to n-1. Initial guess is made for the temperature profiles in the effects and the preheaters. Iterations are performed in two loops on the preheaters and the evaporators. Solution starts at the last effect and proceeds towards the first effect. Completion of the iterative procedure results in determination of the temperature profiles, salt concentration profile, and flow rates of brine and distillate. Results are used to determine other system parameters, which include the performance ratio, the specific heat transfer area, and the specific cooling seawater flow rate. The system parameters used in generating the model results are: The seawater temperature, Tcw, and salinity, Xf, are 25C and 42000 ppm. The salinity of rejected brine, Xb, is 70000 ppm The temperature of rejected cooling water, Tg, is 35C. The boiling temperature in the last effect, Tn, is 40C. The sum of the fouling heat transfer resistance inside and outside the tubes in the preheaters and the evaporators, Rf+Rfo. is 1.75x10-4 m2 C/W. - The thermal efficiency of the preheaters, Ni, is 90%. The tube outside and inside diameters, 6. and d, are 31.75 mm 19.75 mm. The brine velocity, V, inside the preheater tubes is 1.55 m/s. The range for the top brine temperature in the first effect is 60-110 C. The range for the number of effects is 4-12. Solution Method of the Detailed MEE Model The developed model contains a large number of highly non-linear algebraic equations. The equations are solved by a modified fixed point iteration technique developed by El-Dessouky and Bingulac, 1996. The method is simple, but yet powerful and has proved to have a rapid convergence rate. The solution process starts with setting values of system parameters, which include salinity of intake seawater and rejected brine, temperature of intake seawater, temperature of rejected cooling seawater, and boiling temperature in effect n, tube length and diameter, vapor and brine velocities inside the tubes, evaporator area (constant in all effects), and area of preheaters in effects 2 to n-1. Initial guess is made for the temperature profiles in the effects and the preheaters. Iterations are performed in two loops on the preheaters and the evaporators. Solution starts at the last effect and proceeds towards the first effect. Completion of the iterative procedure results in determination of the temperature profiles, salt concentration profile, and flow rates of brine and distillate. Results are used to determine other system parameters, which include the performance ratio, the specific heat transfer area, and the specific cooling seawater flow rate. The system parameters used in generating the model results are: The seawater temperature, Tcw, and salinity, Xf, are 25C and 42000 ppm. The salinity of rejected brine, Xb, is 70000 ppm The temperature of rejected cooling water, Tg, is 35C. The boiling temperature in the last effect, Tn, is 40C. The sum of the fouling heat transfer resistance inside and outside the tubes in the preheaters and the evaporators, Rf+Rfo. is 1.75x10-4 m2 C/W. - The thermal efficiency of the preheaters, Ni, is 90%. The tube outside and inside diameters, 6. and d, are 31.75 mm 19.75 mm. The brine velocity, V, inside the preheater tubes is 1.55 m/s. The range for the top brine temperature in the first effect is 60-110 C. The range for the number of effects is 4-12
