Multi-parameter intelligent control system for controlling boiler main steam temperature

Abstract

The invention discloses a multi-parameter intelligent control system for controlling the boiler main steam temperature. The multi-parameter intelligent control system for controlling the boiler main steam temperature comprises a water supply system and a main steam system. The main steam system is provided with a boiler steam pocket, a first level superheater, a first level desuperheater, a platen superheater, a second level desuperheater, a second level superheater and a steam collecting header, wherein the first level superheater, the first level desuperheater, the platen superheater, the second level desuperheater, the second level superheater and the steam collecting header are sequentially arranged on a steam output gas channel of the boiler steam pocket. Through mutual effect and cooperation of an internal model controller, a temperature reduction control system, a third disturbance module, an internal model module and a self-adapting PID correction module, control over the main steam temperature is achieved, the main steam temperature is stabilized, and cumulative deviation of the main steam temperature is reduced. The multi-parameter intelligent control system for controlling the boiler main steam temperature has the beneficial effects that the main steam temperature is stable, response to disturbance signals is rapid, the influence on main steam by disturbance is reduced, and the cumulative deviation of the main steam is small.

Description

technical field [0001] The invention relates to the technical field of temperature control of thermal power boiler main steam, in particular to a multi-parameter intelligent control system for main steam temperature of a boiler. Background technique [0002] As one of the three important equipment (boiler, steam turbine and generator) in the process of thermal power generation, the boiler is the most important production equipment, and it is the key to power the steam turbine during the operation of the power plant. [0003] In the process of power generation, the temperature of the main steam (also called superheated steam) at the final outlet of the boiler superheater is an important control parameter of the boiler unit, and its control quality directly affects the safe and economical operation of the entire unit. Since the superheater of the power plant boiler is in operation, its temperature is close to the maximum temperature of the metal of the superheater. If the stea...

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Problems solved by technology

However, this modified operation mode has brought new problems. During the adjustment process, the water pressure of the main pipe will fluctuate with the change of the boiler steam volume, and the flow interference of the desuperheating water valve will also increase accordingly, resulting in various desuperheating. The control accuracy of the steam temperature at the outlet of the device is poor

Since the current control method does not directly incorporate the required main steam temperature into the control system, the accumulation of steam temperature deviations in each control section will eventually cause the outlet main steam temperature to deviate from the required temperature value

[0006] In the actual process, each control section adopts simple conventional PID control. When the main steam temperature deviates from the required temperature value range, the final main steam temperature value is manually observed, and the outlet steam of each desuperheater is manually set in sections. The temperature control value is used to indirectly control the final main steam temperature. Therefore, the requirements for operators are very high. Not only do they need rich relevant professional knowledge, but they must also have a proficient level of control. If the control is not timely, it is difficult to quickly It is obvious that this control method is difficult to achieve precise control of the main steam temperature.

Through consulting a large number of relevant literature, the current domestic boiler main steam temperature basically adopts this control method, that is, the current control method cannot meet the requirements of precise automatic control

[0007] Due to the large inertia and delay of the controlled object in the process of boiler main steam temperature control, as well as various interference effects such as steam flow, flue gas heat, and desuperheating water flow fluctuations, the combined effect of these factors further reduces the influence on the main steam temperature. controllability index

Based on the above-mentioned system and defects, the structure of the system cannot be greatly changed, and independent water supply to the boiler drum, primary desuperheater, and secondary desuperheater cannot be performed, and the defects of the main steam temperature control of the boiler cannot be changed.

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