Automatic Control Of Boiler Feed Water Study

This thesis discusses boiler make-up water treatment automatic control system by analyzing craft process and work principle of boiler make-up water system. Boiler make-up water treatment automatic control system applies Siemens S7 300 PLC.In recent years, with the parameters of power generators continue to improve, boiler make-up water treatment in power plants increasingly stringent quality required. Because the materials of high-performance equipments is higher water sensitive than Low performance, equipment will result in salt accumulation, scaling, corrosion and other damages with a slight decrease in water quality supplies.These situations will seriously affect the normal operation of power plants and reduce the economic efficiency of power plants. So, how to improve the operation of boiler make-up water treatment becomes top priority of power plant.Based on the characteristics of boiler feedwater system, both hardware and software of the boiler's makeup water control system are designed. The hardware of this syetem adopts Siemens 300 PLC which makes the syetem efficient and stable. The upper program is designed by using Siemens WinCC software, so the control parameters of the syetem can be modified and set with the technical requirements, it has a good openness. The interface of system graphics is vivid, intuitive and easy to monitor and operate. The system has graphical configuration, trend curves, alarm records, data processing, report output and other functions. The hypogynous program is designed by using Siemens Step7 software which possesses real-time monitor equipment operating status and various parameters of the system, make circuits controlled automatically and equipment working in best condition.The system is reliable, easy to operate and has strong anti-interference ability. Since the system was put into use, it has continuous operation more than one year.