Extended Period Simulation of Pressure-Deficient Networks Using Pressure Reducing Valves

Abstract

Generally, the water distribution networks are designed for peak demands so that under normal operating conditions pressure is adequate to meet the nodal demand however, due to this, the pressure remains excessive when the consumption is low. This leads to huge water leakages and pipe bursts due to excess available pressure. These excess of pressure can be reduced by operating pressure reducing valves. Moreover, the pressure deficient conditions of water distribution network depends on many factors such as excess demand (i.e., fire fighting demand), location and elevation of nodes, location and pressure setting values of pressure reducing valve, ageing of pipes (i.e., increase the pipe roughness) etc. In exceptional situations, pressure deficient condition also may occur when there is a fire demand while pressure reducing valves are in operating condition. The available literature of the pressure deficient condition as well as optimal location, number and their pressure setting values of pressure reducing valves are analysed by mathematical programming or optimization methods. Normally, it is cumbersome to the field engineers to use the any toolkit utility functions. Hence in this study, the pressure deficient condition is analysed via the method of modified pressure-deficient network algorithm without using EPANET toolkit functions which are coupled with pressure reducing valve operation. A benchmark problem is analysed and compared for the proposed method. Further, a real water distribution networks is analysed introducing fire demand at junction/distribution node using fixed and diurnal nodal demand pattern coupled with and without pressure reducing valve operation in a single hydraulic simulation.