In the building materials industry, gas rotary kilns are not only used for calcining cement clinker, but also for calcining clay, limestone, and drying slag; In the production of refractory materials, rotary kilns are used to calcine raw materials to stabilize their size, increase their strength, and then process them into shapes. Next, we will introduce the thermal system of gas rotary kilns.
Gas rotary kiln calcination is the most important process in cement production, which involves complex thermal and chemical processes. The thermal system of gas rotary kiln directly affects the production, quality, and energy consumption of cement clinker.
Due to the many factors and complex objects that affect the thermal system, domestic and foreign peers have conducted extensive research on its control issues and proposed effective control schemes such as fuzzy control and expert control. However, due to excessive reliance on specific objects, they are difficult to promote and apply.
At present, the overall control of cement rotary kilns in China is still in manual or semi-automatic mode, which relies on manual observation of flames, combined with relevant measuring instruments, to comprehensively judge the operating status of gas rotary kilns, and manually adjust various control quantities. Obviously, this control method is greatly influenced by human factors and cannot be controlled in a timely manner. Even experienced operators find it difficult to maintain the rotary kiln in optimal working condition for a long time. Therefore, there is an urgent need to seek a satisfactory and universally applicable control method.
There are many factors that affect the thermal system of gas rotary kilns, mainly including coal powder feeding rate, raw material feeding rate, kiln body speed, kiln system pressure, secondary air temperature, flue gas composition, raw material burnability, coal powder quality, etc., and there is also a strong coupling effect between these factors.
It is difficult to establish an accurate mathematical model for a control object with multiple factors, slow time-varying, distributed parameters, nonlinearity, large time delay, and strong coupling. Conventional control based on mathematical models is ineffective. This project adopts personification intelligent control technology, comprehensively considers various factors that affect the thermal system of gas rotary kilns, uses clustering analysis method to divide the factor space, establishes operation mode, simulates human operation experience based on operation mode, determines control strategy, realizes intelligent control based on pattern recognition, and achieves satisfactory control effect.