The Design And Application Of Distribute Control System Of Main-pipe Unit Power Plant

DCS,based on large-scale industry produce process and increasingly complex control object,aimed at synthesis automatization of produce process.It is according to principle of decompose and coordinate in systems engineering,and developed the new style control system.At the begin of 1990s,20 centurys,the advent of DCS completed independence of each thermal engineering control system.Adopting mature and dependable DCS can alleviate working intensity of operator and the more important effection is that it can insure the run of unit with safety,economy and high efficiency. Recently,with the DCS increasingly mature,run optimize software which based on new control and manage theory, is applied in produce process gradually popularized.It turn DCS into a general network with safety and economy run,control,manage.At present, the DCS is applied abroad in large-scale power unit and seldom in medium and small-scale unit.The paper analyze the design and application of medium and small power plant main-pipe unit's DCS, and put forward material project combined with the design of Nanjing High-technology Xingang power company's #4 boiler.The whole system comprise DAS, MCS, SCS and FSSS.We do fixed value disturb test with each simulation control systems after design,configuration,debug of DCS.The result of the test shows excellent result of each control system. First, the paper analyze function constitution, hardware collocate,system characteristic and communication network of DCS,and introduce the major four control systems and method of configuration.Then, the paper makes an analysis and research of the combustion control system of parallel boilers, and put forward a main steam header pressure control system for boilers in parallel operation based on direct energy balance. This control project can make the boilers in parallel operation with response to the variety of main steam header pressure rapidly. The control system can eliminate the influence between different combustion control system of different boilers.It is convenient to adjust parameters of controller.The property of control system is good and reliable to run and the system can be applied to medium and small power plant main-pipe unit consist of boilers with different capacity.Furthermore, the paper make detail analyse and research to main-steam temperature control system which is emphases and difficulty in power plant control systems. The paper not only investigate dynamic object characteristic of superheat-steam temperature and operational principle of series steam control system,but also research on superheat-steam temperature state variable control project in theory. Because of high-dependability hardware, abundant software function of DCS, advanced control software can be convenient used in DCS.It make some difficult problem to simply, which the problem is hardly to be solved by routine control method. It is low investment and cost that appling indigenous DCS in supervise and control system. There are widely application prospect.