Electrically powered pumps are one of the largest consumers of electrical energy in industry today and for the water industry there’s no contest. Pumping uses the most energy. Energy costs are by far the largest component of Total Cost of Ownership for pumps and pumping stations.
Pumps play a critical role in the supply of clean water and the removal of wastewater across the water network. They generate the pressure which moves water from the source, through water treatment plants, on to the consumer, after which they move wastewater to treatment plants and eventually back into the water cycle. It’s very important that these key assets are ready to run when needed, are effectively maintained and run reliably, efficiently and optimally.
Understanding how the type of pumps most commonly used in industry behave is very important, so it’s good news that they’ve been around since the 17th century. Pump operation is quite predictable, as shown by ‘pump curves’ which are basically graphs of ‘head’ or ‘pressure’ plotted versus flow. A pump running at a constant speed has basically ONE head value and ONE flow value which corresponds to the ‘Best Efficiency Point’ (BEP). Running them at lower flows and higher pressures or higher flows and lower pressures than BEP could, for example cause increased bearing and seal wear. In addition, the pump will not run at optimal efficiency and will not offer the best value for each kWh of electrical energy. Running the pump at its BEP saves energy and wear on the pump.
Pumps play a critical role in the supply of clean water and the removal of wastewater across the water network
It is obvious that running at one speed, one operating pressure and one flow in water and wastewater applications, is not practical. Demand changes with consumer usage based on the time of day and seasonal factors. Today, Variable Frequency Drives (VFD’s) are widely in use as they can effectively move the BEP around to match current operating conditions by adjusting the speed of pumps to match supply capabilities with demand. Pumps are adjusted to meet current and projected demand plus a safety margin. Today, this is largely a manual process and it works pretty well; is there a better way though?
Enter 21st Century technology where the digitization trend brings the capability to gather operational information from all corners of, even the most geographically spread, water networks. Collecting data from the network (e.g. from smart meters) could allow seasonal and hourly trends to be identified and turned into actionable intelligence. Pump station output setpoints can be revised and returned to those same corners of the network almost in real-time. Advisor software packages can monitor pump station performance, identify energy wastage, premature wear conditions and where/when there is a need for preventative maintenance. This will reduce manual inspections, unplanned downtime and operating costs. Mobile technologies allow staff to view operating status information in the palm of their hand. By just pointing a tablet at the pump, augmented reality techniques can display pump operating data in an easy to understand form so what needs (or doesn’t need) to be done is clear.
Instead of manually adjusting pump set points it could be done remotely to both meet real-time demand and save energy. Pump performance can be monitored with software advisors that guide staff in taking the right actions to ensure energy consumption is optimal, long term reliability is maximized, maintenance costs are reduced and unplanned downtime is avoided.
Centrifugal pumps have been around for hundreds of years. Digitizing the water network with 21st century technology offers the possibility to run them more reliably and efficiently than ever before.
Learn more about how digitization can help improve the efficiency and reliability of your pumping operations in the e-Guide here.