Method and system for automatically controlling motor-driven feed-water pump

Abstract

The invention provides a method for automatically controlling a motor-driven feed-water pump. The method comprises the following steps: reading the actual rotating speed value and instruction value of the motor-driven feed-water pump; processing the actual rotating speed value of the motor-driven feed-water pump on a non-linear basis, and carrying out the subtraction operation on the processed actual rotating speed value and the instruction value of the motor-driven feed-water pump, so as to obtain the deviation value of the two values; or alternatively, processing the instruction value of the motor-driven feed-water pump on a non-linear basis, and carrying out the subtraction operation on the processed instruction value and the actual rotating speed value of the motor-driven feed-water pump, so as to obtain the deviation value of the two values; and processing the deviation value by carrying out the scaling operation, integral operation and differential regulation operation, and controlling the opening degree of a scoop tube of an electro-hydraulic coupler of the motor-driven feed-water pump by the processed deviation value. The invention can effectively regulate the rotating speed of the motor-driven feed-water pump, avoid scrambling for water when the motor-driven feed-water pump and turbine-driven feed-water pump are in parallel operation and improve the regulation quality and service efficiency of the automatic feed-water regulating system. The invention further discloses a system for automatically controlling the motor-driven feed-water pump.

Description

technical field [0001] The invention relates to the field of feedwater adjustment control, in particular to a method and system for automatic control of an electric feedwater pump. Background technique [0002] With the continuous reduction of coal resources, improving the power generation efficiency of thermal power units is one of the basic measures to achieve "energy saving and emission reduction". The water supply system of a thermal power plant is usually equipped with a steam-driven feedwater pump and an electric feedwater pump. When the electric feedwater pump and the steam-driven feedwater pump are running at the same time, if the operating personnel manually adjust the speed of the electric feedwater pump and the steam-driven It is very large, so the system usually automatically adjusts the speed of the electric feed water pump and the steam feed water pump. However, when the electric feedwater pump and the steam-driven feedwater pump are running at the same time a...

AI Technical Summary

Problems solved by technology

However, when the electric feedwater pump and the steam-driven feedwater pump are running at the same time and the water supply is automatically adjusted, there are the following problems: the feedwater pump command issued by the water supply master is sent to the turbine electric The command of the water pump is directly transmitted to the MEH system, so the actual speed of the steam-driven feed water pump and the command of the feed water pump are in a linear relationship; however, the relationship between the opening of the spoon tube of the electric feed water pump and the actual speed of the electric feed water pump is non-linear, so in the normal water supply adjustment system During the adjustment process and the load change process of the unit, it is easy to cause the speed change of the steam-driven feed water pump and the electric feed water pump to be out of sync.

[0003] Due to the non-linear relationship between the opening of the spoon tube of the electric feed water pump and its actual speed value, when the electric feed water pump is running alone or when two electric feed water pumps are running at the same time, the relationship between the water supply adjustment command and the actual speed value of the electric feed water pump is also It is non-linear, so after the automatic adjustment of the water supply of the electric feed water pump is put into use, the adjustment quality of the water supply regulation system will also be affected due to this non-linear characteristic

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