The Study Of Computer Control Of Hot Water Boiler

In this essay, aiming at the characteristic of hot-water boiler- circulating pump control system in heating system, the quasi-equilibrium temperature difference fuzzy control algorithm which is based on the difference between supply and return water temperature is put forward through summarizing and analyzing the artificial experience. In subsequent research, self-adaptive fuzzy controller is designed for applying into the frequency speed change control of hot-water boiler- circulating pump, through the combination of the quasi-equilibrium temperature difference fuzzy control algorithm which is based on the difference between supply and return water temperature and classic fuzzy control theory.In this article, it systematically research the peculiarity of the conventional PID control and fuzzy control in their respective fields, which is according to the technical requirements of temperature of boiler heating- circulating pump control system. It tries to structure a fuzzy PID controller by using the combination of PID control method with fuzzy control method. And, this controller will play these two methods'respective advantages. There are lots of combination ways for PID control and fuzzy control. This article based on fuzzy self-tuning PID control algorithm. It will be seen in this article that the fuzzy self-tuning PID controller has been designed according to the characteristics of the object under control, and that the detailed design process has been explained particularly.In hardware, Siemens S7-300 programmable controller and Siemens MM430 Inverter will be used as a core control by system design. In terms of software on the backwater temperature for temperature and so the use of the proposed fuzzy control algorithm, the control system regulating the use of fuzzy self-tuning PID control algorithm. In the program, the fuzzy interrogation table is extracted from fuzzy-rule by using off-line calculating method, and fuzzy control quantity output is queried through online method. The appropriate value is given in accordance with the variation of temperature outdoor in this system through querying temperature difference control table. And then, re-query the parameters of fuzzy PID control table; add the PID parameters correction value into reference value for getting PID parameter instantaneous value. At last, run the PID operation to get control quantity, and apply it to controlled object actuator.