The Energy-Saving Application Of Condensate Pump For High Voltage Converter

With the target of the energy saving and emission decreasing issued by China'12th-five year plan, energy saving and emission decreasing for coal power play a key role because coal power has large energy consumption. Coal power unit capability is usually designed by the power peak value. It is necessary to timely change the flow of pump with the power load's big operation range. This paper studies the condensation pump of 300MW unit and designs a high voltage variable speed drive system for condensation pump. With the adjustment and control of the variable speed drive, it improves production efficiency, reduces the cost and saves the energy, effectively.First, this paper analyses working principle for condensation pump and weakness of general throttle of condensation pump. And an energy saving project for variable speed drive energy saving is designed. When the flow and load of condensation pump is falling, timely adjusting the speed of converter avoids the waste of energy.Second, it achieves the system framework and main power parts of design and type for high voltage converter based on the operation parameters of condensation pump. This paper particularly analyses the structure, working principle and control measures of Siemens Robicon chosen by this project. This converter adopts low voltage power cell in series with simple structure, high reliability and advanced technology. Further, it effectively makes harmonic waves eliminated and power factor increased.Third, a closed loop system for high voltage converter and a logic interlock device are designed for the condensation pump's process control requirements. A set of high voltage converter can drive two motors. That means the condensation pump can switch between variable frequency and working frequency when failures come. For ensuring the power unit running smoothly, DCS can perform the logic program to prevent the sudden change of pressure and level of deaerator.From the actual operation data of high voltage converter for condensation pump of 300MW power unit, the result is remarkable for the variable speed drive system designed by this paper. That system eliminates noise and water hammer effect , extends equipments life and improves the condensation pump efficiency and automation level. This variable speed drive system is welcome by the end user.