Optimal Location and Sizing of Scour Valves in Water Distribution Networks

Abstract

Scour valves in a water distribution network are used to remove sediments that get deposited in the pipe and also to drain off water whenever it gets contaminated. The main governing factor associated with the design of a scour valve in a large water distribution system is the time of emptying water from all the connected pipes as quickly as possible. The network located in the flat terrain requires a driving head preferably at the source that can empty the volume of water available in the entire pipe network under the action of scouring velocity. It is customary to locate the scour valves at the lowest elevated points if the network is in a hilly terrain. In contrast, in the case of flat topography, such a location is seldom available. This paper presents a simple approach to size a scour valve based on the time of emptying the chosen portion of network and also to find the number of scour valves needed and its nodal location to drain off water simultaneously from the network having a flat topography. To solve the formulated optimization model for scour valve design, a differential evolution (DE) optimization algorithm was applied to minimize the number of scour valves required to drain off the water within a stipulated time. Hanoi and Apulian networks are considered to illustrate the proposed approach for optimal location and sizing of scour valves. The results of the optimization have shown the appropriate locations and optimal size of the scour valves.