The Design Of Boiler Heating Systems Based On PLC

With China's economic development, resources and the environment has become increasingly acute contradictions, so that the modernization of our country is facing a formidable challenge. As an important energy source conversion equipment, heating system of the industrial boiler consumes about one-third of China's coal. However, the majority of China's current operating boiler system's security and efficiency is generally lower than the national standard. So it's great significance to achieve automatic control for boiler with computer.On the basis of the boiler control system for some University, the paper presents a overall control thinking, the system designed to heating in winter includes superordinate computer control system and the subordinate system. To meet all the campus's winter heating, it gives a complete control strategy which combined with time and outdoor's temperature. The design of the system is modularized and each part can optimize alone, it's convenient for the whole system to update and control manage. The system is completely opened, so the user's investment can be finely protected. The subordinate system which designed with simens PLC(STEP 7) controls and inspects all the system's parameters, such as efflent pressure, stream flow, backwater temperature, etc. The superordinate system which designed with WINCC in order to display the window of start/stop, parameters set interface, historical curve , an so on. And all the systems are used Fieldbus to exchange datas.The system has advantages such as stable and reliable running, flexible operation, convenient maintenance, and friendly interface, etc. It is proved by field experimental operation that the control system proposed not only can realize automatic control of boiler burning process efficiently, but also reduced energy consumption greatly and effectively improved the level of boiler control management.