When a pump became an energy-generating turbine
In industrial processes, valves are familiar components. Could a pump turbine be an energy-efficient solution to replace energy-consuming valves?
Pumps and fans are the most typical electric motor driven applications. According to our statistics, about half of the electric motors pump fluids or blow air. For example, in Helsinki, about 95,000 cubic meters of water is pumped daily (everyday household water consumption is about 150 liters / person), first cleaned into households and subsequently as a waste water to the Viikinmäki wastewater treatment plant. Due to the volume, the energy-efficient control of pumps and fans is also interesting from a research point of view.
In the EFEU (Efficient Energy Use) research project, as part of CLIC Oy’s SHOK consortium projects in Finland, ABB has collaborated with Sulzer, SKF and Lappeenranta and Tampere University of Technology. The most interesting project for energy saving was the pump turbine research, where a normal pump operated as an energy-generating turbine.
The centrifugal pump is simple. The impeller in the pump housing causes the pumped fluid to move. Pumping can be controlled with variable speed drives (VSDs) efficiently while saving energy. If necessary, this same equipment can also recover energy from the fluid flow and feed it to the grid. A good example of this is a hydro power plant. Hydro power plants are typically megawatt-grade and size of large houses. In the study, this same idea was brought to the kilowatts – that is, in practice, devices that can be lifted by hand. At the Lappeenranta University of Technology, Lauri Nygren (under the link to his diploma work) studied in his thesis.
In industrial processes, valves are well-known components. We are researching the pump turbine to be an energy efficient solution for replacing energy-consuming valves. This is just one example of how well the traditional process can bring a new perspective and at the same time save or even generate energy. Energy price related scenarios are more uncertain. In uncertainty, a smart thing is to use energy efficiently – to optimize your own energy use and to apply the latest results without a hesitation.
Lauri Nygren’s Master’s Thesis ‘Hydraulic energy harvesting with variable-speed-driven centrifugal pump as turbine’: http://urn.fi/URN:NBN:fi-fe201702281885
Jaakko Hyypiä’s Master’s Thesis ‘Hydraulic energy recovery by replacing a control valve with a centrifugal pump used as a turbine’: http://urn.fi/URN:NBN:fi-fe2016111528541
EFEU Final Report: http://efeufinalreport.fi/