Research On Scheduling Methods Of Large-scale SWRO Desalination Plant Under Uncertain Conditions

With serious shortage of freshwater,seawater desalination technology has been widely used as one of the effective methods to alleviate the water crisis in coastal areas.Reverse osmosis is an important desalination technology.With the scale expanding of reverse osmosis desalination system,it is a necessary method to improve production efficiency and to reduce the total cost that using optimizing technology and making reasonable plan.The thesis is mainly focused on optimization scheduling methods under uncertain conditions.Main conclusions are as follows:(1)A static optimization scheduling problem of SWRO system is researched in the thesis.Based on the analyzing of seawater desalination process,the system model is established with a objective function of minimum system operation cost.Constraint condition and boundary conditions are established either.The optimization model is solved by using rolling optimization method combined with a differential evolution algorithm.The simulation results show that the method is effective.(2)The scheduling method of SWRO desalination plant under uncertain freshwater demand is studied.First of all,rolling horizon scheduling(RHS)procedure is used to solve this problem.The result is almost same as static scheduling one,that shows the high practical utility.And then,a robust expected scheduling model is built based on the chance constrains programming and the Hoeffding theorem.The results show that the model can improve the robustness of system.(3)The scheduling method of SWRO desalination plant under random machine breakdown is studied.Considering limited of performance and stability,a rescheduling model is established with an objective function of minimum difference between the reschedule and the previous one.A local repair method based on rescheduling algorithm is proposed to solve this model.The simulation results verify the effectiveness of the method.(4)On the basis of theoretical research,an optimization and scheduling software is designed for SWRO system.The software mainly includes a scheduling system and an equipment maintenance management system.The design process of the software is discussed in detail.At the end of the thesis,contributions of this research are concluded,and the further research is pointed out.