The Application And Research On The IMC-PID Strategy For The PH Controlling System Of Sewage Treatment

Sewage treatment is an important way to alleviate water shortage and advance the sustainable development of social economy. p H controlling is the important aspect of sewage treatment, and its effect has a direct influence on the final quality of the processing. The neutralization reaction process of sewage treatment has the complex characteristic of nonlinearity, large time delay and strong interference. In the actual production with complex working condition, the control result is susceptible to interference of many factors, including their own chemical constituents, impurities,temperature variation and so on, which makes p H controlling become complicated. As a result, this subject has important theoretical significance and practical engineering value.Taking the neutralization reaction process as an object, this paper describes the process characteristic of sewage treatment through the research on the mechanism of the reaction process. In addition, the research status of p H control technology is introduced and the influence factors of p H controlling is analyzed. On the basis of the above, the IMC-PID was proposed to simulate and compare with the PI control method which is commonly used in actual engineering, the superiority of IMC-PID was finally verified. The main research contents of this paper are as follows:1. Chemical mechanism in reaction process is analyzed. On the basis of the ionization balance and law of conservation of mass in reaction process, dynamic and statistic models of p H neutralization reaction are established with continuous stirred tank reactor as an object. In addition,the basic characteristics of the neutralization reaction process are demonstrated and the influence factors of p H values are concluded.2. Internal model control strategy is studied in this paper. Meanwhile, the basic properties of the strategy are described and the dynamic following characteristics of the control strategy is simulated and analyzed. For p H neutralization reaction of sewage treatment process, IMC-PID scheme has been designed. By using the MATLAB software, the paper carried out the simulation to the IMC-PID strategy and analyzed its control effect.3. The strategy is applied to control system of ash dam backwater for the Heat Power Plant of Maanshan Iron & Steel Co. Ltd. The selection and configuration of hardware is carried out,moreover the system is designed to two-level computer control architecture. It can completely content the requirements of the field condition.