Profibus Fieldbus-based Boiler Control System

To meet the demand of tobacco production, Qujing cigarette factory began to build three new 35t/h boilers in 2004. With the entire plant application of advanced production technology and improve management of the new boiler energy supply security capabilities set higher requirements, the new boilers must be integrated to control system as a whole, the boilers processes complete control, energy data collection management, equipment management, and data communication and so on. So, we use the bus-technology to build a boiler control system for this purpose.In the distribution control system, DCS system and between different fields with upper Intranet, Internet information difficult to achieve interconnection between networks and information sharing, so the distribution control system is a closed and special distributed control system.The bus-technology is just for it, it used the open field bus, the network will operate with each other to the scene of the signal controllers and instrumentation interconnection, make up of a system-wide control, at the same time control functions completely decentralized to the field and reducing the cost of installation and maintenance costs. Therefore, the bus-system is a real open, distributed and decentralized control systems, and it has gradually become a mainstream product of control systems.In 1987, Siemens company with other 13 enterprises and 5 organizations of scientific research , have joint promulgated the PROFIBUS field bus technology, PROFIBUS standard has become an integral part of the international field bus standard IEC61158.This selection subjects of the boiler is be controlled by PROFIBUS field bus, it use the SIMATIC PCS7 system of Siemens company. We research and design from the following, and achieve boiler control tasks.1. Automatic detection: Using instrumentation for industrial boilers heat continuous measurement and display parameters, and provide protection and security for automatic adjustment process parameters.2. Automatic adjust the boiler running: To adjust automatically the boilers continuous production processes to increase operational efficiency.3. Failure prediction, failure to deal with : According the parameters and the boilerssafe operation data, dynamic analyze the data, forecast the equipment failure, and warning us. 4. Security chain protection : System has the function of overpressure, the waterlevel is too low to protect the security chain.These achievements have been applied in three 35t/h boilers of Qujing cigarette factory control projects, and for the operation of boilers economically and safely, for the boilers control to a certain extent similar reference and demonstration value.