Features of Automatic Control of Technological Parameters of Water Level in the Drum Steam Boilers

Abstract

The three-pulse system of automatic control of the water level in the boiler drum received maximum distribution in the energy sector, as well as its modifications, which have the following disadvantages : the presence of static control errors at the end of the transition process in the development of internal disturbances and disturbances of superheated steam flow; large level deviations with sharp and significant changes in the load, which often leads to unloading or shutdown of the boiler or power unit. To eliminate these drawbacks, invariant systems for automatic regulation of the power supply of the drum boiler were previously developed. In work the system of automatic control of technological parameters of water level in a drum of steam boilers is considered. The description of control systems and a detailed description of the electrical power systems of the control system are given. Various methods of tuning the PI controller of a typical three-pulse automatic power control system are considered. The application of the method of structural-parametric optimization and the theory of invariance makes it possible by changing the structure of the system and optimizing the dynamic adjustment of the automatic power control system to significantly improve the quality of maintaining the water level in the boiler drum. Invariant automatic control systems eliminate static control errors under all influences and can significantly improve the quality of maintaining the level under variable conditions. The methods are proposed to significantly improve the quality of water level control in the boiler drum, eliminating the shortcomings of the typical automatic control system. The results of the work can be used in the design of power control systems of steam drum boilers. The results obtained can be used in the development of adaptive control systems for other thermal power facilities.