Research On Full Process Optimization Scheduling Of Reverse Osmosis Seawater Desalination System

As one of the effective methods to solve the shortage of freshwater resources in coastal areas,Seawater Reverse Osmosis(SWRO)technology has received more and more attention.There are many uncertain factors in the process of a large SWRO system.We should make the reasonable production scheduling for the system,and properly arrange the water production plan of each unit,which is conducive to improving the utilization rate of equipment and effectively reducing the cost of water production.In this paper,the robust scheduling problem of the system under two uncertain factors is discussed for the whole process of SWRO system.The main research contents and conclusions are as follows:(1)The whole process model of SWRO desalination system was established.The whole process is divided into four main parts:seawater water intake,pretreatment,reverse osmosis and post-treatment.The unit operation models and related economic models are given in this paper.Then a full-process cost model of the SWRO desalination system are built by integrating the above models of the four parts.Aiming at minimizing the total process dispatching cost of the SWRO system,the optimal scheduling problem that satisfies the constraints of the unit's water production,the water demand of the reservoir,and the constraints of water supply is proposed.(2)The static scheduling problem of the whole process SWRO system is discussed and the scheduling model of the system is established.In order to obtain more accurate solving and less computing time,this paper combines genetic algorithm(GA)and simulated annealing algorithm(SAA)into a genetic-simulated annealing algorithm(GSAA) to solve the optimization proposition.The simulation results show that the GSAA used in this paper has a certain improvement in the optimal solution,the average solution and the average solution time than traditional GA.(3)Considering the objective existence of uncertain factors in the actual SWRO process,this paper discusses the strategy of robust optimal scheduling of SWRO process under uncertainties.Two typical uncertainties,fluctuation of seawater temperature and changing of freshwater demand,are discussed in this paper,and a robust pre-scheduling model is established using chance-constrained programming.A simulation is operated with the optimal goal of minimizing the cost of SWRO,the temperature fluctuation as a random variable,and the water consumption fluctuation as a fuzzy variable.The solution is calculated by a GSAA under these constrains.The simulation results show that when considering the influence of temperature fluctuation,the optimal cost is higher than that static state,but it is closer to the actual operation cost more.At the same time,the robustness of the former is greatly improved than the latter,which means that the robust scheduling has more superiority to overcome the influence of random fluctuations and more practical than the static scheduling.(4)Based on the above optimization scheduling scheme,an optimization scheduling software is developed for SWRO system.The design and development process of the whole software is briefly introduced.Finally,this paper summarizes the foil text and proposes the research direction that can be carried out in the future paper.