Project Background
A municipal waterworks in Sichuan Province was operating six fixed-speed centrifugal supply pumps with a combined installed capacity of 660kW. Under the original direct-on-line configuration, all pumps ran at full speed regardless of network demand — resulting in chronic energy waste during off-peak hours, persistent over-pressure in downstream pipelines, and accelerated wear on pump seals and bearings.Solution Goalliance designed
Solution
Goalliance designed and delivered a complete variable frequency drive retrofit for all six pump units. Six ABB ACS880 series VFDs were integrated into a custom-engineered control panel, implementing PID closed-loop constant pressure control via remote pressure transmitters installed at key network nodes. A lead-lag pump sequencing logic ensures even wear distribution across all units. The system integrates fully with the waterworks’ existing SCADA platform via Modbus TCP, enabling unmanned remote operation and real-time energy monitoring.
Results
- Energy savings：38%, annual saving of approximately 1.5 million kWh
- Outlet pressure stability improved from ±0.12 MPa to ±0.02 MPa
- Annual maintenance cost reduced by over 60%
- Pump seal service life extended from 8 months to over 24 months
- Payback period: under 2 years
- CO₂ emission reduction of approximately 1,000 tonnes per yearScope of Supply Custom VFD control panel
Scope of Supply
Custom VFD control panel design and fabrication · PID pressure control programming · SCADA integration · On-site commissioning · Operator training · 12-month warranty support
