| With hydraulic turbine capacity and the continuous improvement of the head, the unit vibration stability problems have received increasing attention. The plant is the main supporting structure of the unit, the vibration will inevitably pass into the plant, thereby inducing plant structural vibration. Especially as the capacity of the units and the plant size increases, the vibrational energy corresponding increase vibration problems may be more serious. The plant is an important part of the units the supporting system of the units generate the energizing force in the plant on, likely will cause plant whole or partial member of the vibration, including the vibration and noise, but also there may be induced vice plant of the vibration and noise, affecting the normal power plant run and staff comfortable environment.The vibration of the turbine group is a very complex problem, was going through a lot of long-term research, its accurate prediction and perfect solution is still very difficult. Especially with the increase of the capacity of the units and head, giant water unit vibration problem is particularly prominent.Large and medium-sized hydropower stations at home and abroad have unit vibration induced structural vibration, and even lead to structural damage affecting the normal operation of the power station instance. Pressure fluctuation through the spiral case and draft tube effect in a the plant underwater reinforced concrete structure, induced structural vibration. Large Francis turbine pressure pulsation often engendered stationary random phase and amplitude in the flow channel is distributed.Therefore, if the unit is difficult to completely avoid vibration exists, you should analyze the vibration intensity and its impact, and then study the the damper damping measures or ways to improve the structural design. Hydraulic vibration in the Three Gorges large hydraulic machinery plant design study have carried out an in-depth study. These studies very important reference value.The large pumping station underground plant for instance, do the following work:1.The pumping station machine pier volute structure not only the geometry of complex, open holes in the structure, the structure is very complex. This paper combines the ANSYS finite element software, reference to project drawings, the use of the software pre-processing module, solid geometry model of the plant structure. In order to get a better body unit to improve the accuracy of the finite element analysis using ICEM before processing system processor pier, metal spiral case structure (as well as other fixed components), volute perimeter concrete structure to generate a finite element model to calculate the required, the density of the cell geometry of the control depending on the modeling of the structure of the smallest member and the position of the loads and passing mode:Calculate the range of similar, such as into the water pipe into the hole, the machine pit into the hole, the floor hanging objects hole holes are simulated.2.Based on the finite element model of the plant has been completed, using finite element software ANSYS, the modal analysis, the calculation, vibration of plant source characteristics and inherent analysis unit according to the natural vibration frequency and vibration load frequency of structure, according to a certain standard, the structure of the resonance check.3.Through the analysis of data item experiment, dynamic analysis of the unit load and hydraulic exciting vibration loads were determined, and identified several typical conditions. Application of ANSYS finite element software, the harmonic response analysis method to compute and analyze the typical working conditions. Treatment of the condition of displacement data obtained under the typical parts, the maximum vibration velocity under different working conditions, structure of the typical parts of the acceleration amplitude and RMS value. With reference to the relevant specification requirements, a detailed analysis and evaluation of results. |
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