On Parameters Estimation of the Input-output Chlorine Residuals Models of Drinking Water Distribution Networks

This paper presents some aspects concerning the estimation of the parameters in the input-output chlorine residuals models of drinking water distribution networks (DWDNs) used for transportation of treated drinkable water from the water treating plants to consumers. To kill the microorganisms that can cause the waterborne ills, disinfection is usually the final treatment stage in the drinking water plants. Usually, the disinfectant used in DWDNs is chlorine because it is inexpensive and effectively annihilates a variety of disease-causing organisms. To maintain high-quality drinkable water in such distribution networks it is necessary to regulate the chlorine residual concentration within a prescribed set of bounds. Since the DWDNs are large scale systems with high uncertainties and time varying delays, in order to obtain useful models for control, in this paper, some aspects regarding the estimation of parameters of the input-output chlorine residuals models are analysed. The model parameters are time varying and heavily dependent on the hydraulics which is a main source of uncertainties in chlorine concentration models. Using the input/output data and a priori knowledge of the system, in this paper will be presented a method for the estimation of bounding values corresponding to model parameters so that the obtained model could be used in a robust predictive control method.