Study On Decision Support System Of Optimal Control Of Chlorine Residue In Water Distribution Networks

Water Distribution System (WDS) is one of the urban lifelines, and the study ofits operational management plays a very important role in urban management.Traditional operational control of WDS is only focused on the hydralic objectives,and the control objectives include hydraulic pressure and water quantity. Based onthis idea, many Optimal Scheduling Systems (OSS) have been established andbecome one of important methods in the operational management of WDS. Sincewater quality control is the necessary content of the management of WDS, waterutilities establish and renew the OSS including control of both hydraulic and waterquality is inevitable trend and urgent requirement of informatization construction anddevelopment.Optimal control system of chlorine residue is the advanced form of OSS andtakes the chlorine residue as control objective, water quality model as decisionevaluation foundation, water quality monitoring network as data source, controldecision of chlorine residue as analytical core, executive facilities of control ofchlorine residue as realization mean in order to achieve the task of scientificmanagement and control of water quality in WDS. The Decision Support System ofOptimal Control of Chlorine Residue (DSSOCCR) can provide various models,real-time and historic data, expert's experiences and decision schemes for the decisionmakers.The purpose of this paper is: optimal control of chlorine residue is added basedon the OSS of hydraulic control in existence and DSSOCCR is established in order tocontrol the chlorine more safely and economically. It will reinforce the ability ofdecision makers to manage water quality in WDS. This paper has finished theresearch works as follows.(1) The integrated frame and flow chart of DSSOCCR and the OSS of hydrauliccontrol is studied. The control concept and modes of chlorine residue, the theoryand application of OSS, the relationship between control of chlorine residue and OSS, and the content of DSSOCCR in WDS are analyzed. Based on aboveresearch, the integrated scheme and flow chart are designed.(2) Study on establishment the model of chlorine residue which is suitable forlarge-scaled WDS.1) Study on the mathematics model of bulk reaction coefficient of chlorinedecay in WDS. The disinfection mechanism of chlorine is studied,experiment about bulk decay coefficient is designed, data is abtain from realexperiments, non-linear regression is used to analyze the data, and themathematics model of bulk decay coefficient considering the evironmentalchange is obtained.2) Study on the calibration of pipe wall reaction coefficient of chlorine modelin WDS. The calibration method of pipe wall coefficient of chlorine modelfor large-scaled WDS is studed. The calibration process is speeded upaccording to combine the meta and detailed model. And clustering methodis used to enhance the precision of chlorine model.(3) Water quality monitoring sensor is designed optimally in order to get morereliable data. In the process of optimal location of water quality sensor,catastrophic warning and routine mornitoring are optimized together. These twoobjectives are combined into the optimal location process, and this method canmake full use of the costly monitoring equipments.(4) Study on the mathematics model of DSSOCCR. The decision process, objectivefunctions, constraint conditions, solving method are studied. The boosterchlorination is analyzed and integrated to DSSOCCR.(5) Study on the application of DSSOCCR. Based on above research findingsincluding water quality model and data, a macro model of one large-scaled WDSis established. Applying the optimal theory of combined macro and detailedmodel, the application of DSSOCCR in real large-scaled WDS is realized.This paper completed four creative achievement as follows:(1) Based on the thought, "using macro model to optimize and detailed model toverify", the theory system of OSS is well established which integrates the controlof hydraulic and water quality in WDS. This paper presents the decision objectives, decision targets, solving scheme and solves the key problem ofDSSOCCR in WDS.(2) Establish the the mathematics model of bulk reaction coefficient of chlorinedecay. This model makes the relationship between the bulk reaction coefficientand environmental arguments such as chlorine concentration out of factory, totalorganic carbon (TOC), temperature. It also provides a more accurate fiducialvalue for calibration of pipe wall reaction coefficient.(3) Applying the thought of combining both macro and detailed model to optimize,this paper design a new combinational algorithm CORS-RBF-GA. This algorithmrealizes rapidly the calibration of pipe wall reaction coefficient of chlorine modelof large-scaled WDS.(4) Present a more scientific mothod of optimal location of water quality sensor. Thismethod which combines the catastrophic warning and routine mornitoringtogether can enhance the utilization ratio of the costly monitoring equipments andreliability of data.