Great Lakes Water Authority (GLWA) operates one of the large water systems in United States. GLWA pays over US$22M in its water facilities energy bills, about 85% of which is paid for pumping. GLWA has been seeking ways to make its system more efficient. To evaluate realtime pumping efficiency, GLWA has developed a program called real‐time efficiency evaluation for pumping stations (REEPS).
REEPS utilizes records from various intelligent meters installed at its water pumping stations to evaluate real‐time efficiency for each of the pumps on duty. The installed meters include a power monitoring meter and a differential pressure transmitter for each pump as well as a station flow meter. Real‐time meter measures are sent to GLWA’s SCADA, the Emerson Ovation. The REEPS program has been developed in Ovation to automate real‐time pump efficiency calculations. To evaluate real‐time pump efficiency, pump flow rate is required to compute pump output energy (hydraulic energy). Due to the limitations of pump unit pipeline length, it is not practical to install a flow meter for each pump. Real‐time records from differential pressure transmitters and the calibrated pump head characteristic curve data are used to compute pump output energy. The station flow meter measures were used to calibrate a pump head characteristic curve when only the pump was on duty.
The REEPS is being referenced by GLWA’s operators as a guide to run the system more efficient. The REEPS results are used to identify the pumps that are oversized or associated with low efficiency. The REEPS outcomes are also used to update the pump head and efficiency curves in a hydraulic model used for GLWA’s ongoing project of real‐time pumping energy optimization.
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