Digital technology is helping pump operators to make their systems more resilient, by tackling everything from ragging to turbidity. But even greater developments are around the corner.
Whether it’s involved in moving water, sludge or indeed any other substance, a pump’s cargo is always precious. Inefficiency is always unacceptable, and building resilient pump systems that are capable of dealing with changing conditions and unexpected events, essential.
For the water industry, this is especially true. With the publication of its PR19 methodology, Ofwat set out its view of what is needed to ensure a resilient long-term future for water. Central to this is that the industry must collaborate if it is to achieve the innovative solutions that are required not only to create more resilient systems, but to tackle other challenges, both existing and new, that lie ahead.
Closer collaboration will also help unlock the potential offered by the digitalisation of pump-related technology, as well as the increasing provision of cloud-based technology and services. This seismic shift has already begun. By working with suppliers, utility providers are finding that it is possible to improve pump resilience by utilising functions built into existing assets, such as digital variable speed drives (VSDs), low voltage motors and pumps.
For example, today’s VSDs come packed with smart features and functions that can be used to make processes work harder and better for longer. Two of these functions which are found in some VSDs are helping the industry to tackle the longstanding problem of turbidity.
Controlling turbidity and suspended solid levels in raw water pumping is vitally important in ensuring the efficient extraction and supply of water to consumers. Water with high levels of turbidity is more likely to carry bacteria and living organisms which can cause disease.
For this reason, turbidity and suspended solids concentrations are tightly regulated and need to be carefully monitored to ensure that limits are maintained within DWI (Drinking Water Inspectorate) compliance limits.
Plugging into the power of digital
The use of VSDs on pumping applications can reduce turbidity problems. When a pump changes its speed as slowly as possible, it helps achieve the lowest turbidity values for the water being moved or extracted. Two features built into today’s VSDs help reduce turbidity – quick ramps and soft pipe fill.
The soft pipe fill function manages the pressure of water filling the pipeline with a gentle approach. This helps to avoid sudden pressure peaks and reduces the risk of water hammer which can cause damage to the water pipes and reduce the risk of built up sediment from being disturbed. Meanwhile, the quick-ramp feature protects bearings when a submersible or borehole pump is started.
Quick ramp allows a pump to reach its minimum speed as quickly as possible to extend pump bearing life, ensure problem free operation and prevent unplanned outages. The quick-ramp functionality allows the use of dedicated ramp sets to quickly accelerate and decelerate the pump. The first ramp allows immediate water flow to lubricate and cool the bearings. The second ramp is used to reduce turbidity as the pump is not producing any flow in this region. By combining quick ramps with a long normal ramp up and ramp down time, the VSD will ensure proper lubrication, efficient ramping in the no-flow zone and as slow as possible ramping after that to ensure minimal turbidity. Smart functions such as these are just some of the ways that today’s digital drives are helping pump systems to work harder.
Another in-built, but often overlooked feature of a VSD, is adaptive programming. While not its main purpose, this building block programming tool can be used as a ‘get out of jail free’ card when installations don’t go to plan. It is used to customise the operation of VSDs in cases where the drive parameter settings are not sufficient, should additional
functionality be required. For instance, a UK water utility tried an emergency stop shut down on a new set of pumps, but the harshness of the stop caused the building to vibrate. Using adaptive programming, the drive was coded to detect stop situations and come to rest more steadily, as well as recovering from a black start. Without adaptive programming the cabinets would have needed to be re-wired and the project delays would have been hugely expensive.
Digitalisation of VSDs and motors will continue to directly – and positively – impact on the resilience of pump systems. The next leap forward is being provided by the launch of cloud-based remote maintenance services that enable pumps (and other motor-driven systems) to be monitored and maintained from half a world away, if necessary). A suite of services is now available, including remote assistance, condition monitoring and, more latterly, predictive maintenance. These are distinctly different services but all use the cloud to transmit real-time data on the health and function of motor-driven applications. In this way these services are set to transform the way VSDs, motors and now pumps are maintained and operated.
While digitalisation is opening up a new world of machine-driven possibilities to improve the resilience of pumps, there is no doubt that the best results are coming from good old fashioned, human collaboration. This was brought home recently with the results of a project ABB is undertaking with a utility provider to reduce leakage at its pumping stations.
The utility in question has already succeeded in eliminating downstream leakages by installing VSDs on pump motors that were previously connected direct-on-line (DOL). The drives are installed at sites that were experiencing a higher than acceptable level of bursts. Using a series of high-speed data loggers, the utility was able to identify the cause of these bursts as pressure transients caused by DOL starting. Following installation of the VSDs, at one site the number of leaks fell from nine in one year to none.
To build in even greater resilience against leaks, the utility is continuing to work closely with ABB engineers to investigate using the adaptive programming function within ABB drives to monitor and change pressure set points remotely. This will be achieved by feeding the drive information, via the cloud, from a pressure sensor located at the critical point. Statistical modelling will then be applied to the data, determining the optimum pressure set point for the pump system at any moment in time. The VSD could then adjust the speed of the pump motor continuously, in response to changing conditions.
It is a work in progress and involves constantly tweaking the way we use the technology in order to get the required results for the utility. This illustrates perfectly what can be achieved when like-minded organisations work together to use cloud-based technology to provide innovative solutions to the biggest challenges facing their industries.
ABB (ABBN: SIX Swiss Ex) is a pioneering technology leader in electrification products, robotics and motion, industrial automation and power grids, serving customers in utilities, industry and transport & infrastructure globally. Continuing a history of innovation spanning more than 130 years, ABB today is writing the future of industrial digitalization with two clear value propositions: bringing electricity from any power plant to any plug and automating industries from natural resources to finished products. As title partner of Formula E, the fully electric international FIA motorsport class, ABB is pushing the boundaries of e-mobility to contribute to a sustainable future. ABB operates in more than 100 countries with about 135,000 employees. www.abb.com