Modelling, simulation and analysis of pressure reducing valve operation in water distribution networks and their related greenhouse gas emissions

This thesis explores the physical behaviour of industrial pressure reducing valves (PRVs) used around the world for effective water distribution and network pressure reduction. The mathematical models developed as part of this project showcase the steady state and dynamic behaviour of PRVs when changes are made to its control system or external variables within water distribution networks (WDNs) acting to disturb the PRV system (used to simulate water demand within the network). Analyses on the performance of the models to quantify any pressure setpoint offsets or low PRV head loss complications as experienced in Western Australia’s Interconnected Water Supply Scheme (IWSS) network by Water Corporation was done and validated with industry contacts alongside a comprehensive literature review to validate general PRV dynamics. Downstream pressure offsets attributed to higher PRV pressure setpoints were related to the low head loss issues of PRVs (i.e. when PRV head loss ≤ 10m) and classified into three distinct categories. Further simulations were done to verify the PRV as an effective disturbance rejection device with equations formulated to predict and quantify any PRV offsets in the downstream pressure, either as a result from pressure setpoint changes or disturbance inputs. Furthermore, work done to relate hydraulically controlled PRVs (i.e. with no power supply) and GHG emissions was completed to enable water service providers to estimate the true financial and environmental costs of PRVs within their WDNs. These costs were quantified within a theoretical WDN based on the IWSS in which the energy analytics related to all PRV operations (that is commonly unaccounted for by water service providers) totalled $672,000/year and 5040 tons CO2/year. The models created can be adapted to any PRV. Whilst further work can be done to refine the models developed within this thesis paper, they provide a strong foundation for academia and industry alike when analysing PRVs and estimating the commonly overlooked GHG emissions associated with water distribution