A MINLP Approach for Planning the Renewal of Pipes in Drinking Water Networks

This article presents a novel Mixed Integer Nonlinear Programming (MINLP) approach for finding a renewal plan of pipes in a water distribution system. We formulate a MINLP model for finding the times of renewal and suited measurements of pipe dimensions in a multi-year planning horizon. The model includes a multi-period hydraulic simulation of the distribution systems behaviour thereby respecting the friction caused headloss as a nonlinear constraint. We apply the MINLP solver Bonmin to a test network and present first numerical results. The models embedding into a general solution framework for water network problems consisting of network reduction and simulation steps in an interated way, is beign discussed. This latter discussion corresponds well to the recent results by C. Hallmann for the problem of tank planning within the mentioned solution framework that has been presented there for the first time.