The Overall Modeling And Simulation Of Circulating Fluidized Bed Boiler

Circulating fluidized bed(CFB)combustion is a new technology of coal cleaning combustion, which can burn wide ranges of low grade fuels in an efficient and clean way. CFB boiler is evidently different from ideal operating condition which often occurs in power plants in either designation or operation. Therefore, establishing the mathematical model of CFB boiler and using it to analyse the CFB boler is very important. The model also has significance on further improvement and solving the actual operantion problem.On the base of analysis of the energy utilization and the environment of our country, first of all, a summary was made to describe the advantage and disadvantage of CFB boiler and its development direction.Then, the status of CFB boiler in the world was introduced and an emphasis on the problem of CFB boiler and some achievements were made. At the same time, many mathematical models of CFB boiler systerm were discussed.A whole mathematical model of CFB boiler was established in this paper. The whole mathematical model was programmed in modular modeling way, which plotting out module in terms of the system's equipment. Then Visual VB was used as the tool to develope the module of CFB boiler's equipment. These modules can be expanded and modified easily. The simulation software was established according to these modules. The software has been finally complied to an application software bundle. It also can run independly in Windows.The whole model was used to study the operating characteristics of CFB boiler, The paper analyse how the operating parameters influence the operating characteristics, mostly including the static characteristics under design condition and varied conditions. And some conclutions about CFB boiler operation characteristics were arrived at. This paper has already done four simulation trial: rated conditions, load change, ash content change and moisture content change. Simulating results show that: the variational disciplinarian of the module's status parameter accord with the practical disciplinarian and those validate the model, the modules have commonality widely, the overall mathematical model can simulate all operating characteristics of CFB boiler rightly.