Dynamic compensation method of attemperation water impact leading steam temperature measuring point in boiler steam temperature control system

Abstract

Provided is a dynamic compensation method of an attemperation water impact leading steam temperature measuring point in a boiler steam temperature control system. According to the method, an attemperation water impact leading steam temperature measuring point correction factor on-line computation module is arranged in the overheating and reheating steam temperature cascade control system of a power station boiler, the correction factor of the attemperation water impact leading steam temperature measuring point is computed on line through the module, the difference between a steam temperature set value and a controlled steam temperature feedback value is divided by the correction factor to compensate changing of inertia zone object gain, output of an auxiliary adjuster is multiplied by the correction factor to compensate changing of leading zone object gain, and accordingly dynamic compensation of the attemperation water impact leading steam temperature measuring point is achieved. The method achieves dynamic compensation of the attemperation water impact leading steam temperature measuring point in the steam temperature control system and has the advantages of being good in compensation effect, field conduction is convenient, control effect is good, control quality of the overheating and reheating steam temperature cascade control system of the power station boiler can be guaranteed, and safety and economy of operation of the power station boiler are improved.

Description

technical field [0001] The invention relates to a dynamic compensation method capable of effectively preventing the overheating of a boiler in a power station and the deterioration of the control quality of a reheated steam temperature cascade control system when desuperheating water impacts a leading steam temperature measuring point, and belongs to the technical field of boilers. Background technique [0002] Superheated and reheated steam temperature in power plant boilers is the main parameter affecting the safety and economy of boiler operation. The superheated steam temperature of the first and second stages of large boilers is adjusted by spraying water to reduce temperature; the reheated steam temperature is adjusted mainly by flue gas baffles or swing burners, supplemented by water spray for temperature reduction. Because the controlled object has many unfavorable characteristics such as large inertia, large delay, and nonlinearity, it is difficult to control the st...

AI Technical Summary

Problems solved by technology

But this is not the case for the outer loop. Since the inertia and delay of the object in the inertia zone are large, a slight change in the object gain will seriously affect the system control quality

For a cascade control system with well-tuned PID controller parameters, the response of the controlled variable will become very slow when the outer loop gain becomes smaller, and the control system will become unstable when the outer loop gain becomes larger

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