Research On Throttle Control Optimization Of Condensate Pump Of 350MW Thermal Power Unit

The fossil energy reserves and environmental pollution has seriously constrained the pace of China's economic development,therefore,energy conservation strategy in China is imperative.The condensate pumps and other auxiliary equipment in thermal power plant are driven by motor,the variable load operation process of thermal power plant using speed control equipment to adjust the motor speed,it can achieve auxiliary equipment energy-saving operation.Different speed control methods have different degrees of energy-saving capacity,therefore,choosing and designing the best condensate pump throttling control mode has practical significance.In this paper,the cooling control method is optimized based on the condensate pump of the 350MW unit in Kangbashi district,analyzed the advantages and disadvantages of different throttle control methods,designed the selected frequency conversion throttling method,adopted the experimental test to analyze the performance of the variable frequency throttle system.The main conclusions of this paper are as follows:1)In order to improve the operating efficiency of the thermal power generating units and to save the power consumption,the cooling water pump of the Kangbashi thermoelectric 350MW unit selected the frequency conversion speed control mode and the frequency conversion speed mode is the unit series multi-level voltage source type high voltage inverter.2)The inverter is designed as pulse width modulation,the main circuit adopts the module series method,and realizes the high voltage direct output by connecting several independent low voltage variable frequency power modules in series.High-voltage inverter input isolation transformer adopting phase-shifting transformer,the output side through the inverter PWM modulation technology make the output is multi-level,and making the output voltage wave form of inverter is close to the sine wave without output filter,so it can be directly connected to high voltage motor.3)The high frequency inverter control design two ways of the local and the remote control.The frequency given mode includes the control interface manual frequency,the analog input frequency given and the terminal frequency given,choose any one of them according to the actual situation.4)The test of the equipment showed that the relevant parameters of the variable frequency throttle system are stable both in load reduction and load increase conditions.And the load response speed of the unit is improved,the energy saving effect is obvious and the system is reliable.