How would you compare the digital twins for the Swedish and Canadian water systems?
Jean-Luc Daviau: Digital twins are all about supporting utilities and their operators. The digital twin achieved in Linköping, Sweden provides real-time, detailed decision support to engineers and operators as they tackle real-world water supply challenges. It’s inspiring to know it was done and is now in use. For the Toronto and York Region systems in Canada, we aspire to predict long-term, cumulative wear-and-tear using the systems’ digital twins. Both day-to-day operations and emergency management have a role to play in water management.
Thomas Johansson: The digital twins for the Swedish and Canadian systems use different sensors and solution algorithms. The Linköping model can self-generate and solves flows and pressures every 10 minutes to predict gradual changes in the water network; the data in the Toronto and York Region models change monthly or yearly, but the “faster” digital twin can predict changes in the network from gradual to nearly instantaneous. For example, valve closure simulations support an operator’s most frequent emergency response, which is to isolate an area with a break. Right now, in the Linkoping model, we can gauge how pressures and storage levels respond to valve closures but without the transient pressure waves.
How then can a “faster” digital twin change the way water utilities carry out their operations?
Jean-Luc Daviau: While many emergency scenarios such as power failures can be predicted ahead of time, the same is not true of the best way to respond to a pipe break or fire that can occur anywhere.
Networks are a heterogeneous fabric of pipes that have “folds” due to topography, “cuts” due to rail or highway corridors, and “strings” that link distant parts via tunnels or transmission mains. Disturbing any point of this surface affects the entire system in ways that are hard to predict.
A digital twin allows operators to isolate the area by closing water valves, and the model can also generate a list of the impacted customers. This can be done today using a geographic information system [GIS] framework and reasonably detailed hydraulic models. A “faster” digital twin can do the same while also indicating the fastest safe speeds or sequence to close these valves or fire hydrants, to avoid causing wear-and-tear—or another break elsewhere. Gaining such insight requires consideration of every pipe and the dynamic equipment parameters that represent a system’s response to fast events, both of which are available through a hydraulic transient (“faster”) model.
Digital twins require GIS and SCADA links but benefit most from large-scale IoT sensors and cloud-based data to store, process and serve-up, hundreds of times, the pressure and flow measurement data. Of course, faster pressure sensors are also needed for a “faster” twin. The faster computers and high-speed sensors we have today enable us to use a “faster” digital twin to tackle transient event simulation with a high level of detail, just like we do for everyday events across entire water systems.
There are two key concepts to get across to engineers and system operators as they look toward the future: Number one, a system’s response time increases with size, making it more vulnerable to changes in flow or pressure; the same pump stop can be tolerable one year and problematic 10 years later. Number two, transient mishaps can wreak havoc within systems. Picture a dam break; it’s fast and destructive, but it is visible. Liberating that kind of energy underground would present immense challenges in terms of response, containment and resolution. With the right tools, utilities and their operators can prevent major issues and more effectively manage problems when they arise.
Linköping Water Supply Network, Real-time Modelling – Sweden
Client: Tekniska Verken AB
Tekniska Verken AB is the municipality-owned company in the municipality of Linköping, Sweden that serves the Linköping area: 1,568 km² with a population of 163, 000.
Tekniska Verken contacted WSP some years ago and asked for help to update an old hydraulic model over the water supply network. The aim was also to start the work toward establishing an online model for the network, continually fed with data from the SCADA system (Supervisory Control And Data Acquisition) system. WSP’s part in the project was to build the model and connect it to the SCADA system, help Tekniska Verken to carry out capacity studies, and train those working in the system so that they now run the system themselves.
Tekniska Verken had a growing need for an updated hydraulic model due to extensive growth in the municipality with a lot of new housing and industry areas. A growing population calls for the ability to carry out accurate capacity studies and to optimize all assets as well as system performance in an aging water supply network. Optimization includes identifying problems—such as those related to pressure, leaking pipes and water quality—and underperforming areas.