A preliminary investigation on the operational efficiency of centrifugal pumps operating in single-branch, single-pump systems

Pumping systems are among the most energy-consuming applications, making its efficient operation a matter of great relevance. In recent years, efforts to improve the efficiency of these systems have followed two approaches. The first involves the design and development of new efficient pump models, in studies primarily based on the internal flow behaviour and impeller geometrical parameters. This approach, albeit useful, does not consider whether these efficient pump models have been correctly selected. The second approach addresses the energy-saving potential achievable through the pumping system itself, including the proper pump selection, which is a research area that still offers opportunities for improvement. The primary objective of this work is to create a methodology to identify whether a pump has been efficiently selected for a given hydraulic system. To achieve this, the two main criteria currently used for evaluating the efficient selection of pumps are discussed: the POR-Q and the POR- \(\eta\) $\eta$ . The results demonstrate that the proposed methodology correctly identifies high-efficiency pumps for operating in a given system. It is shown that the flow rate interval where the pump can operate with high efficiency, as determined by the POR- \(\eta\) $\eta$ criterion, is wider than the interval obtained using the POR-Q criterion. This expansion in the available range of pump operation using the POR- \(\eta\) $\eta$ criterion allows for greater availability of pumps that meet the system requirements and respond well to energy-saving strategies. This finding enables a wider choice of pumps, thereby facilitating the decision-making process.