Dynamic Simulation And Combustion Model Of 600MW Coal Burning Boiler

With the fast development of national economy, power generation unit capacity in our country is increasing at a speed of 7~8% a year. At present, about 75% of generation sets are still coal-fired unit in our country, most of which are coal burning unit and this tend will continue for a long period. In our country, two main problems existing in coal-fired power plant are low energy utilizing ratio and serious environmental pollution, which are also important factors constraining our country's electric power industry even the sustainable development of whole national economy. To develop high-parameter, large-capacity power generation unit can increase energy utilization ratio and improve environmental pollution. Because the request of environmental protection is more and more strict, in order to solve problems of power shortage, low energy utilizing ratio and environmental pollution, it is the most feasible and effective method to establish large-scale and high effective coal-fired generating unit. Furnace chamber is one of the most important element of steam boiler. In furnace, there are complex physical chemistry processes of combustion and heat transfer occurring and various elements which take part in the process affect each other, which make these processes in furnace very complex. Process of combustion is a key factor which is relative to boiler production capacity and reliability of production process, and determines economical efficiency of boiler operation. With the development of computer technology, mathematical model of furnace heat transfer developed fast. Although mathematical model can not replace experiment in the study of furnace character, modeling and simulation method offers a new research technique, which is important in theory and experience. Establishing dynamic mathematical model of boiler and simulation study is a effective means to understand dynamic characteristics of boiler unit. The main purposes are: 1) to judge the unit dynamic characteristics and analyze the effect to dynamic characteristics caused by changes of structural parameter, then put forward ultimate method on structural design to improve unit dynamic characteristics. 2) to design reasonable control system according to dynamic characteristics. 3) to establish training simulator for the operators training and operation analysis, failure prediction and diagnosis. The dynamic mathematical model of power unit is the most important content in power station simulator. The paper chooses 600MW subcritical natural circuit boiler made in DongFang Boiler Works as research subject. The paper establishes furnace combustion one-dimension steady state model and gets one-dimension distribution of temperature and pollution gas in furnace. Dynamic simulation model of the unit is established by the means of Modular Modeling System (MMS)6.0. Based on it, simulation experiment on disturbance of fuel, air capacity, feed water, water in fuel is performed and gets response curves of the boiler main parameter. Simulation results show that the models established in this paper reflect dynamic characteristics of boiler unit correctly. The research work will play a good theoretical guide role for boiler design and optimizing operation.