Abstract : This paper introduces the energy-saving principle of high-voltage frequency converters and their application in the condensate pumps of the 2×220 MW unit of Yungang Thermal Power Plant. It elaborates on the characteristics of high-voltage frequency converters, their successful application experience in the plant, and the requirements for the operating environment.
Keywords : condensate pump; high-voltage frequency converter; application
Application of High Voltage Frequency Converter on Condensate Pump of 220 MW Unit M a Hong-bo (Shanxi Datang International Yungang Thermal Power Co. Ltd., Datong 037039, China)
Abstract : Energy saving principle of high voltage frequency converter and its application on condensate pump of 2× 220 MW units were introduced． The characteristics, experience on the successful application in the power plant and demand tO operation eviroment were presented．
Key words : condensation pump; high voltage frequency converter; application
Condensate pumps are one of the main auxiliary machines in the steam turbine thermal system. Their function is to draw condensate from the condensate tank, pressurize it, pump it into the low-pressure heater for heating, and then send it to the deaerator. Simultaneously, they supply desuperheating water to the turbine's third-stage desuperheater and are driven by frequency converters. Previously, because condensate pumps operated at a fixed speed, the outlet flow could only be adjusted by control valves, resulting in large throttling losses, high outlet pressure, severe pipe damage, low system efficiency, and frequent leaks, leading to energy waste. Furthermore, the control valves, being electromechanical adjustment structures, suffered from poor linearity, low adjustment quality, and low automatic activation rate; frequent on/off adjustments easily led to various malfunctions, increasing on-site maintenance and wasting resources. The condensate pumps of the 2x 220 MW units at Shanxi Datang International Yungang Thermal Power Co., Ltd. (hereinafter referred to as Yungang Thermal Power) boldly used high-voltage frequency converters, achieving significant economic benefits and gaining valuable experience.
The Yungang Thermal Power Plant's 220 MW unit is equipped with three 50 kW condensate pumps, with two normally in operation and one on standby. In the event of a tripping malfunction by the operating pump, the standby pump automatically takes over. The condensate pump is a 6.5LDTN-D8 model, operating at 1480 r/min, and powered by a 355 kW asynchronous motor. The high-voltage frequency converter employs stepless speed regulation, with power consumption varying according to the unit load, thereby improving equipment utilization and achieving optimal economic operation.
For details, please click: Application of High-Voltage Frequency Converters in Condensate Pumps of 220MW Generator Sets
