Energy Saving of Wastewater Pumping Using Proposed Integrated Drive Systems

Abstract

An integrated drive arrangement for a wastewater pumping system was designed and modeled to evaluate the energy saving gained from matching motors with Variable Frequency Drive (VFD) and Programmable Logic Controller (PLC). The proposed arrangement utilizes the affinity laws of centrifugal pumps to predict the performance of a pump under different rotational speed conditions. The specific energy (Es) is used as a measure of the cost effectiveness of the proposed pumping system.Results have shown that a reduction of 10% in pump speed can save 30% in energy of maximum speed. The energy saving potential is carried out for a real-life case study, and a conclusion to replace on-off controllers currently used for most wastewater pumping systems is necessary. The total energy saving account for more than 50% when integrated drive system was applied for a combined sewer pump station.