Control method of boiler water level and its control system

Abstract

A boiler water level control method and its control system, based on the principle of three-impulse cascade control, controls the valve position of the feed water regulating valve; the control system can also compare the upper and lower limit values ​​of the water level from the steam drum with the water level tracking value respectively The signal directly controls the full closing and full opening of the water supply regulating valve. The boiler water level control system working in the above method is composed of three-impulse transmitters for steam drum water level, steam flow rate and feed water flow rate, controller, upper computer, hand operator and electric water feed regulating valve. , The selection module and the comparison module are used to calculate the upper limit value and the lower limit value of the water level, set the limit valve position, and judge the state of the water level exceeding the limit. The system responds quickly and has a high level of automation, reducing labor intensity and ensuring safe operation of the boiler.

Description

Technical field [0001] The invention relates to a boiler water level control method and a control system thereof, belonging to the field of automatic control, and suitable for water level control of industrial boilers and small power station boilers. Background technique [0002] Industrial boilers and boilers of small power stations play a huge role in the production and life of today's society, and there are countless applications in all walks of life. Therefore, the safety of boiler use has attracted widespread attention. In the production process, unreasonable operation, poor management, and improper handling of the boiler will often cause accidents. Most of these accidents are caused by improper boiler water level control. It can be seen that the boiler drum water level control is very important in the boiler equipment control system. The drum water level system is a hysteresis system with large disturbance and nonlinear characteristics, and modern industrial boilers are dev...

AI Technical Summary

Problems solved by technology

However, in the conventional three-impulse control cascade system, due to the "false liquid level", the dynamic characteristic curve when the steam load rises and falls is asymmetrical, and the system parameters are time-varying, so an accurate mathematical model cannot be obtained, almost The control parameters that can adapt to the above-mentioned various disturbances cannot be found, so the control effect is often difficult to meet the requirements. The specific performance is that the water level is easy to overshoot, the system often alarms, the fireman often has to participate manually, and sometimes even stops the water pump, etc. cause system instability or even loss of control

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