Transformation And Technology Research Of Speed Control Sysem In 300MW Unit Electrically-Driven Feed Pump

Facing the growing energy demand, dwindling fossil energy reserves and pressure of reduction, reducing coal consumption rate has become a priority. Among all the equipment in the power plant, the feed water pump consumes the maximum power. So the transformation of the feed water pump for energy saving is particularly necessary.Firstly the paper introduces the working principle and configuration guidelines of the feed water pump, than focuses on the drive scheme and adjustment programs of the feed water pump. The differences of energy consumption about throttle governing and variable-speed adjustment were analyzed. The energy consumption of feed water pump driven by special turbine or by fluid coupling and electric motor was compared by the three indicators of standard coal consumption rate for generating, station service power consumption rate and standard coal consumption rate for power supply, base on which, the direction of the transformation of 300 MW unit speed control system was determined. Than the transformation programs of pre-pump, hydraulic coupling and frequency converters were analyzed detailedly. The transformation programs of the 300 MW unit motor unit with hydraulic coupling speed control system were designed combined with the specific parameters. Finally, the investment and energy savings for pump speed control system transformation were analyzed with the operation state before transformation.The analysis shows that the pump speed control system transformation can save 10.77 million kW·h power and about 3.231 million yuan a year by the two transformed feed water pumps. The transformation program can increase profit about 1.9935 million yuan, and is expected to spend 5 years to recover the investment cost.