Fan Bridge Vibration Response Measurement And Theoretical Analysis

Direct air-cooling plant fan bridge carrying power equipment of a power plant cooling system, and fan bridge vibration problem of direct air-cooling system is the important problem of the support structure design, fan bridge stability is the important indicators of fan safe operation.This paper mainly research contents:in-situ measurement of fan bridge vibration characteristics; theory analysis of fan bridge vibration characteristics; equivalent static crosstalk force and equivalent bearing static counterforce calculations.The specific research results are as follows:(1) Selection of a running actual blower bridge for field measurement, research real vibration magnitude size of the true fan bridge, and the spectrum characteristics of fan bridge;(2) On the basis of the field measurement, Vibration characteristic analysis is conducted,the analysis results show that although truss fan bridge itself stiffness is relatively large,the previous order modes still presents a regular vibration, from the fourth order then presents complex vibration;(3) Under the fan bridge load (fan perturbation forces have obtained from the tests), the real fan bridge vibration is simulated. Studies shows that not consider high frequency influence of the fan perturbation forces, the theoretical calculation result less than measured results, consider high frequency influence, X calculation results is slightly less than the measured results, Y and Z to calculation results basically consistent with test results;(4)During the fan bridge start up and steady running process, the maximum displacement of the fan bridge points is calculated. According to the maximum displacement equal principle, establish the corresponding relationship between equivalent static crosstalk force, equivalent bearing counterforce and fan equipment (fan door leaf, shaft, wheel) weight, and gives corresponding computational coefficient.