Research On Double Closed-loop Ratio Control Method With Fuzzy Dynamic Correction And Its Application In Nitric Acid Production

As an important raw material,nitrate acid is widely used in chemical production,pharmaceutical industry, metallurgy, military and other fields. Sice2007, Nitric acidproduction in China has been exceeded the United States, ranks first all over world,many attention was pay on the excessive growth of production, while the productionprocess control and the product quality assurance was ignored.In the control system of nitric acid manufacturing（Hereinafter referred to astemperature）process, stability of oxidation furnace temperature will effect the safety ofnitric acid producing system, nitric acidt quality and tail gas treatment etc.. Oxidationfurnace is the place where chemical reaction happens between NH3and O2(from theair),Due to the reaction of ammonia is strong exothermic reaction, so, the factorsinfluencing oxidation furnace temperature instability are the amount of ammonia airmixed gas and ammonia content in the mixed gases, so ratio control can be an effectivemeans to achieve stable oxidation furnace furnace temperature stablability.This paper analyses the traditional ratio control application in oxidation furnacecontrol system, point out deficiency, and puts forward a dynamic fuzzy correctionammonia air ratio of furnace temperature control scheme, and a control system designand simulation was carried out. The main content of this paper include:①summarized the Ratio control in development and application in nitric acidoxidation furnace temperature control, analyses the commonly used ratio the defects offurnace temperature control system.②Outlines the nitric acid production process, at the same time, to clarify theessence of the oxidation furnace control system and the production process to achievethe technical index and its essence.Analyzed the actual production process of ammonia nitrate empty ratio control keyproblems, further summarizes the traditional ratio control method in the oxidationfurnace temperature control is difficult to achieve good control effect. For later in thisarticle a new control scheme proposed has laid a theoretical and practical basis.③according to the result of a series of related analysis, combining with the actualcharacteristics of nitric acid oxidation furnace production system, and puts forward theammonia air than fuzzy dynamic correction of double closed-loop ratio of furnace temperature control scheme. According to the actual concrete engineering, the furnacetemperature control scheme for the system design and implementation method in detail.Later, in chongqing a chemical oxidation furnace control system of thetransformation as the background, analyze the related object model or identify theirparameters. The design of ammonia empty than fuzzy corrector.④the simulink simulation experiments, using ziegler Nichols parameter setting,respectively, to determine ammonia flow PI controller, PI controller, air flowtemperature parameters of PID controller.The simulation experiment mainly on the system of anti-interference ability andthe accuracy of temperature in the result analysis, and compared with the traditionalammonia air than double closed-loop temperature control system and variable ammoniaair than the furnace temperature control are compared. Empty, according to the resultsof ammonia than fuzzy dynamic correction of furnace temperature control method,system anti-interference ability is significantly higher than the traditional controlmethod, stable work temperature deviation is less than the commonly used traditionalcontrol. Demonstrates the effectiveness of the proposed control scheme.The last is the summary of the full text and its prospect...