Abstract
Since the 20th century, PLC has quickly been applied to machinery, metallurgy, mining, light industry, and other fields after the first PLC been invented in the late of 1960s. PLC is an overall automatic control equipment which been manufactured by micro-computer technology. PLC has some advantages. It has high reliability. It suit to the high- temperature industrial environment and the adverse environmental like the impact shock .It also can widely used on mechanical equipment, production lines and the production process automatic. PLC has the logic operation function to replace relays for switching control, with timing control functions, numeric control functions, step control functions A/D, D/A conversion functions, data processing functions, communications, networking functions and control functions of stronger watch.
Fuel boilers and city- owned generators of buildings been applied extensively with the development increasingly. The coal combustion boilers used previously have been gradually eliminated .Because it has large number of CO2 and dust pollution of the environment .The corresponding fuel oil boilers has replaced coal-fired boilers and have been widely used in hotels, shopping centers and other buildings. PLC control system applicable to fuel boilers with combustion devices in a variety of imported and domestically fuel boilers to implement fully automatic boiler control, including boiler water control, steam pressure controller, combustion system parameters detection control, instructions control and warning control.
Key words: programmable controller fuel boiler control system