Variable-Speed Optimization of Circulating Water Pumps

Optimizing pump configurations, variable-speed pump setpoints, and parallel pump flow allocation for two 1,050 MW coal-fired units.

Cases with improvement
43 of 49
Average net power gain
+122.2 kW
Estimated seasonal benefit
CNY 506,000

Background

The study focuses on two 1,050 MW ultra-supercritical units. The calculations account for unit load, ambient temperature, condenser back pressure, pump power consumption, and equipment operating limits.

Methods

  • Developed an EBSILON thermal system model and validated it against test and design data.
  • Compiled pump performance curves, pipe network resistance characteristics, and operating constraints.
  • Applied a bilevel optimization framework to determine pump configurations, speed setpoints, and parallel pump flow allocation.
  • Evaluated 49 steady-state operating cases and representative operating days in autumn and winter.

Results

  • Net power output improved in 43 of the 49 operating cases.
  • The average net power gain across all cases was 122.2 kW.
  • Based on 90 autumn days and 90 winter days, the estimated additional generation revenue was approximately CNY 506,000.