A Study On Dynamic Characteristics Of Industrial Tower Equipment

Wind and earthquakes damaged high-rise tower equipment seriously. And it will be even worse, when the inherent vibration frequency of the device equals to its resonance frequency. In order to predict the resonance and the harmful levels of resonance in the design phase accurately, the study on dynamic characteristic of industrial tower equipment has important theoretical significance and social value for ensuring the normal operation of the industrial tower.Firstly, the basic mechanism of flow-induced vibration of the tower, harm and vibration-proof design have been analyzed in this paper. A detailed description of several important parameters of dynamic characteristics of the tower equipment, such as the damping ratio, natural frequency, the tower displacement, locked areas has been made.Then, with the ethylene distillation column in Tianjin Petrochemical, the damping ratio of process tower equipment has been calculated by using different calculation methods. The results show that the calculated values are different by using different methods, and there is a large uncertainty between the calculated and measured values in the damping ratio. Therefore, INV damping method has been used to measure damping ratio of many single tower models in this paper. The dimensional analysis method is used to analyze the damping of tower equipment in order to get empirical formula of the damping ratio. Tianjin ethylene fractionator damping ratio, which uses the empirical formula to calculate, agrees well with the experimental value. The resulting error is small.Finally, the numerical simulation method has been used to analyze the tower itself modal analysis. The two-dimensional numerical simulation and three-dimensional numerical simulation has been analyzed on the tower basin around.(1) Ratio calculated values under different methods are different, and the measured data also has a large gap.(2) The calculated formula of a damping ratios by dimensionless method and the least square method is as follows: logζ=3.0211+2.2085log H+2.499log D-1.95031og M+1.9503log ρ+1.14341og t The formula has been used to calculate the damping ratio of ethylene distillation column. The calculated values are in good agreement with the experimental value, the formula is available.(3) The natural frequency by modal analysis is0.44191Hz and by calculated is0.44Hz, so modal analysis results are more accurate.(4) The tower basin around the equipment to simulate and found while the vector of wind is5.5m/s, the vortex shedding period is2.2s, which is equal to the tower calculated natural period2.25s. So, Tianjin ethylene fractionator has resonance phenomenon. This performance agrees with the range of wind velocity observed in the practical situation when resonance accorded, which also proves the correctness of the numerical model built in this paper.(5) Numerical simulation results show that the presence of different heights vortex shedding phase, so the method by using two-dimensional numerical simulation instead of three-dimensional simulations are imprecise. （a） Tacom a桥破坏之后（b） T a c o m a桥破坏之后...