Actual State of Main Pump Rotation Speed Control in Sewage Treatment Plants and Energy-saving Measures

摘要

In the recent years, the rotation speed control of the main pump using an inverter (VVVF) has been increasing for energy saving purposes. On the other hand, there are cases where power consumption increases due to excessive rotation speed control ignoring pump characteristics. In the present study, we examined the change of operating method based on the power consumption analysis on two sewage treatment plants (located in City A and City B). In this analysis, the operation daily report data of the sewage plant is used, therefore, it can be applied to many sewage treatment plants. The simulation results with minimum rotation speed control showed that the reduction in power consumption is about 10% in city A and about 25% in city B. Especially, we could get about 21% reduction in City B, where the operation method was changed at the site based on the calculation conditions.