2018年10月15日星期一

developments of cooling tower design

Structural analysis of large cooling towers is mostly based on the theory of no-moment of rotating shells. This theory ignores the effects of bending moments and transverse shear forces in the shell equilibrium equation, and most of them use hand calculations, and then program on a small machine. After the calculation year, the research group headed by Professor Sun Tianfeng determined the reasonable wind load curves of the cooling tower through wind tunnel test and actual measurement. These curves have been adopted by the domestic cooling tower design specifications in structural analysis. A thin shell-based moment theory based on straight normals can be used, and a high-precision rotating shell element is used in the discretization format, and then the rotating shell and two static dynamic analysis programs are respectively completed. The program has become the main program used by various power design institutes in China to calculate cooling towers.
There are hundreds of large cooling towers analyzed and designed by these two programs, and the two cooling towers have been designed. In the past few years, it has been continuously improved, so that it can solve more problems, such as the stability of the cooling tower. Analysis of the 'cooling tower structure according to the theory of moments in foreign countries, which is also about from the end of the century to the beginning of the year. The theory of finite element method has been developed more thoroughly.
The analysis of various structures by the finite element method has become Mainstream, and other commercial software has become a routine tool in structural analysis.
Although we have been able to analyze the stress of the cooling tower under the action of white heavy, wind load and uneven temperature field in the early years, we have formed a special software system with unique characteristics, but the actual demand of the project is endless. The design unit has successively proposed the rib and reinforcement ring problems of the cooling tower structure, the cooling tower foundation treatment and piling problems, the cooling tower construction defects such as the bulging problem, the tower opening large holes that must be dealt with for the joint design of the cooling tower and the chimney, Peking University, several electric power design institutes, Hebei University of Science and Technology, and Zhejiang University, etc. Developed some special calculation software for cooling towers In recent years, due to the promotion and application of general finite element analysis software, Zhejiang University and other units have developed secondary software based on general finite element software, and compiled software for software analysis of cooling tower structure. For the stress distribution of the cooling tower New practical needs provide analytical tools that greatly advance and improve the design level of cooling towers Peking University, Tongji University, Hunan University
The unit has carried out a large number of experiments on the rigidity and aeroelastic model of the cooling tower.
the study
On the other hand, as the geometry of the cooling tower is getting larger and larger, the area of the shower is correspondingly increased. Some of the problems that the small tower does not need to consider now become important, especially the problem of nonlinearity with the nonlinear problem of the thin shell theory. Proposed and gradually matured, there are more and more cooling towers analyzed by nonlinear finite element method, and the finite element method is also a more

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