Method and system for frequency conversion control of condensate pump of condensing steam generating set

Abstract

The invention discloses a frequency converting control method and system of a condensate pump of a condensed steam generator set. When a frequency converter is in a liquid control mode, the water level of a deaerator is controlled by the frequency converter and a water adjusting valve on the deaerator, and the frequency converter controls the water level of the deaerator by adjusting the rotating speed. A water feeding main adjusting valve on the deaerator is maintained at certain aperture according to the load of a machine unit; and under the same load, when the machine unit is in a load up stage, the aperture of the water feeding main adjusting valve is maintained to be small, and when the machine unit is in a load down stage, the aperture of the water feeding main adjusting valve is maintained to be large. Simultaneously certain load space can be generated by control of two clamped curves during load up and load down, and frequent aperture changing of the water feeding adjusting valve caused by small load fluctuation can be avoided. The rotating speed of the frequency converter can be lower, the current is small, the output frequency of the frequency converter is in the adjustable and economical range, and energy consumption of the frequency converter is reduced.

Description

technical field [0001] The present application relates to the technical field of frequency conversion control of condensate pumps, in particular to a method and system for frequency conversion control of condensate pumps in condensing steam generator sets. Background technique [0002] The condensate pump is an important power equipment of the condensate system. Its function is to drive the condensate in the steamer into the low-pressure heater for heating and then send it into the deaerator. [0003] The frequency conversion control of the condensate pump is an operation mode of the condensate pump. The power supply frequency of the condensate pump is changed according to the actual condensate flow, the pressure of the condensate tube, and the load of the unit, and the automatic adjustment of the motor speed of the condensate pump is realized through the conversion of the power supply frequency. [0004] Corresponding to the frequency conversion control of the condensate pu...

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Problems solved by technology

[0007] In addition, when meeting the pressure increase demand of the condensate water system, the frequency converter will carry out frequency conversion increase, and the pressure of the main pipe at the outlet of the condensate pump will increase rapidly, which will have a great impact on the water level of the deaerator, which will affect the control of the water supply regulating valve of the deaerator

[0008] Since the sealing water of the steam pump sealing water pump is provided by condensate miscellaneous water, it is directly affected by the pressure and flow of condensate water, and the temperature adjustment of the sealing water of the steam pump is only a simple single-circuit adjustment. When the pressure of the outlet main pipe of the condensate pump changes, the sealing water temperature adjustment circuit of the steam pump will cause large shaking, which will seriously affect the stable operation of the unit

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