Optimal Water Distribution Network Design Accounting for Valve Closure

Flow regulation is always carried out by means of flow controlling devices like valves, flow meters etc. Valve closure is carried out in a pipe network for planned or unplanned operating conditions (e. g. pipe failure) in order to isolate a part of the network. It creates unusual working conditions in the network due to topological modifications. Analysis of distribution system for isolation by means of valve closure should always be performed as a part of the assessment of system reliability. Thus, a challenge for network designers is to optimize pipe diameters versus system management under these abnormal working conditions. The present study accounts for the mechanical reliability with respect to pipe failures due to valve shutdown, and deliver a strategy for the optimal design. The network modification considering valve shutdown is aimed at changing the hydraulic capacity of the connected network by modifying the pressure at the critical nodes. Two types of analysis namely, Demand driven and Pressure driven analysis were performed in this study. A real network in Thrissur district is selected to test the developed strategy for the optimization. Optimization results provide us with four sets of diameter values, which are to be adopted to avoid a condition of pressure deficiency for any type of isolation.