Research And Development On Optimal Operation And Scheduling System In Desalination

With China’s rapid social and economic development, the long-time-existingproblem of scarce fresh water resources is becoming more and more serious,particularly in coastal areas. During the“Twelfth Five Year”Plan period, China willvigorously develop the marine economy. The marine economic development incoastal Zhejiang province has risen to the national strategic level. Solving the problemof a lack of fresh water resources is a key factor in economic development in coastalareas. Reverse osmosis desalination technology is a mature and widely used high-techmethod, through which, stable and reliable water sources can be produced in largescale. However, as the cost of reverse osmosis desalination is relatively high, seekinghow to reduce costs has been the common goal in the desalination industry. With theenlargement of reverse osmosis scale, it is reasonable and necessary to realize highlevel optimized scheduling and management in reverse osmosis seawater desalinationproject, which can make rational use of resources, constitute water preparation anduse plan and lower the costs of desalination of per ton water from perspective ofoptimal scheduling.From the study of the principle, process and optimal scheduling of reverseosmosis desalination, based on prediction of water consumption for per hour andequipment maintenance information, the optimization of water production unit andwater supply from basin was achieved, finishing reducing, emission consumption andcosts of water production from angle of scheduling. Specific research work is listed asfollows:(1) The result of forecasted water consumption of each hour in one day isregarded as an important parameter for the optimized scheduling model of waterproduction and supply. The three forecasting models as of linear moving average, autoregression and trend extension were utilized to predict the hourly water consumptionbetween 2011 May 9th and May 16th. Based on the forecasting results, the predictionerrors were analyzed and a comparison together with explanation was made about themerits and demerits of the three models. Meanwhile, the 2011~2012 annual forecastedwater consumption data was predicted by gray prediction theory.(2) Firstly, the specific optimization operation and scheduling process of reverse osmosis desalination was studied. Then, scheduling background, scheduling goals andscheduling factors were also analyzed. Finally, the algebraic mathematical model wasestablished. The result of the optimized scheduling model of water production andsupply, including water preparation and use plan, adopted the information of the firstand second phase of unit, and was derived by the Cplex solver of the GAMS algebraicmodeling tool. Furthermore, the backstage call technology of GAMS in the softwarewas elaborated.(3) As a major input parameter of the scheduling model, equipment maintenanceplan is an important criterion for whether the unit is available or not. In this section,the various methods for equipment maintenance in main reverse osmosis desalinationequipments were analyzed. Besides, the focus was on chemical cleaning method forthe membrane, how to determine the type of pollution, and how to confect thecorresponding cleaning fluid.(4) After the basic theoretical research on water forecasting, waterproduction-water supply joint optimization scheduling, equipment maintenance, et al,the development of optimal operation and scheduling system on desalination wasinitially realized. The feasibility and requirement of the software development wasfirstly studied in the development. The most important aspect in the development wasthe overall design and software modular design. In addition, database design andsystem debug during the development of the software was briefly described.