Boiler main steam temperature control system

Abstract

The invention discloses a boiler main steam temperature control system. The boiler main steam temperature control system comprises a water supply system and a main steam system. The main steam system is provided with a boiler drum and further comprises a first-level overheater, a first-level temperature reducer, a platen superheater, a second-level speed reducer, a second-level overheater and a steam header, all of which are sequentially arranged on an output steam air path of the boiler drum. Through mutual influences and cooperation of a master controller, a first temperature reduction control module and a second temperature reduction control module, the main steam temperature is controlled, the main steam temperature is stabilized, and the accumulated error of the main steam temperature is reduced. The boiler main steam temperature control system has the beneficial effects that main steam temperature control is stable, the response speed of interference signals is high, influences on main steam from interference are reduced, and the main steam accumulated error is small.

Description

technical field [0001] The invention relates to the technical field of thermal power boiler main steam temperature control, in particular to a boiler main steam temperature control system. 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 running, its temperature is close to the maximum temperature of the metal of the superheater. If the steam temperature is too high, the strength of th...

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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, when the main steam temperature deviates from the required temperature range, the final main steam temperature can be indirectly controlled by manually observing the final main steam temperature value and manually setting the control value of the outlet steam temperature of each desuperheater in sections. , so the requirements for operators are very high, not only requires rich relevant professional knowledge, but also must have a proficient operating level, if the control is not timely, it is difficult to stabilize the main steam temperature within the required temperature range in a short time Obviously, 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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