Simulation of steady state models describing hybrid desalination process using MATLAB software

Mathematical model development for hybrid multi-stage flash (MSF) and reverse osmosis (RO) desalination plants has gained attention among researchers. The hybrid MSF-RO plant has been a promising and upcoming technology in the desalination market due to its efficient and cost-effective operation. The hybrid plant shares common intake and the final product of the MSF and RO plants are mixed. The plant model plays a significant role in understanding and analysing the plant performance. In this thesis, a steady state mathematical model for hybrid MSF-RO desalination plant was developed to ensure the accuracy and reliability of the plant model. The developed model was based on material, salt and energy balance. Thermal and physical properties of the brine, distillate, and steam are considered. These properties are calculated as a function of temperature and concentration. In addition, the performance ratio of the MSF plant is determined by increasing the number of the MSF stages. The developed model incorporates nonlinear equations which are solved using fsolve, a nonlinear system solver, in MATLAB software. The number of the MSF stages considered was six stages. Whereas, a single stage RO plant was treated. The results, in this thesis, were obtained individually for the stand-alone MSF and RO plants. The final results of both plants were then combined. The simulation of the hybrid MSF-RO model showed sufficiently promising results. With the given input data of the feed temperature, concertation and flowrate of both MSF and RO systems, the develop model was used to predict the temperatures and flowrates of the brine, distillate, and cooling brine in each stage. The results obtained were then validated through the comparison with various researchers. Subsequently, the evaluation of the develop model indicated that the model was accurate and can be relied upon. This is in line with the objective of creating a pathway for future works to be carried out for optimisation and control design purposes