PRVs working in parallel configurations – Analysis of dynamics

[EN] Société wallonne des eaux (SWDE) is the most important water production and distribution company in Wallonia, one of the regions in Belgium. Its distribution network stretches over 40,000 km. It covers nearly 200 municipalities and has more than one million connections. SWDE supplies drinking water to nearly 2.4 million people, constituting over 70 % of the Walloon population. Recently, SWDE has launched a major multimillion-Euro project to improve security of the water supply in Wallonia. The project involves a 500/800 mm extension of a 1000-mm wide, over 100 km long pipeline as a backbone of the distribution network, starting from the Eupen and Gileppe reservoirs. The project created a number of engineering challenges and one of them is considered in this paper. The work represents a design of a pressure control station which provides efficient operation over a wide range of flows from 40 m3/h to 1500 m3/h. Additionally, the pressure control scheme needs to work in a stable manner with the downstream flow control system. It is proposed to use two identical hydraulically controlled PRVs connected in parallel without any external PLC control loop. To make sure that such a configuration can be installed in practice it was necessary to carry out extensive simulations to understand the system dynamic behavior for different scenarios.