The Design And Analysis Of Vibration Abatement And Anti-earthquake In Diesel Generator Set

As the internal backup power of nuclear power plant, emergency diesel generator set was important equipment for safety and security of the nuclear power plant. According to the nuclear power plant safety regulations, emergency diesel generator set belongs to the third level of safety equipment in nuclear power plant, and it belong to the class I equipment for seismic. In this thesis,vibration isolation system was designed for diesel generator set,and performance of diesel generator set under seismic was analyzed in three aspects, which were seismic analysis for vibration isolation system, analysis for the integrity of diesel generator set and the safety performance of key components. In order to explore a calculation process of seismic analysis for equipment, and provide some means for earthquake simulation.Firstly, the vibration isolation system was designed and the seismic calculation was conducted. Position of vibration isolator was arranged according to the principle of force balance in each isolator. Calculation and analysis was carried out for vibration isolation system, which contains static analysis, calculation of the inherent characteristics and calculation of forced vibration response and short impulse response. The results show reasonable selection and position arrangement for isolator, and the system does not produce resonance in forced vibration excitation. Performance of vibration isolation system under seismic was analyzed based on dynamic design analysis method (DDAM) , which shows deformation and stress in isolator under seismic loads is less than the allowable value.Secondly, the integrity of diesel generator set under seismic was checked.Three-dimensional model of the unit was build, and the model was meshed to finite element,and the boundary and connection of the finite element model was founded. According to the module of load cases in ANSYS finite element software, the response of unit was calculated on the design conditions,earthquakes conditions,normal conditions accident and accident conditions. And stress and strain of the unit components was analyzed. According to the results, the integrity of unit meets requirements.Finally, the evaluation for performance of key components of diesel engine set was conducted. The safety of components checked using the module of static analysis in ANSYS finite element software and the empirical formula. The stress and displacement of components under seism was calculated, and the stress of connection bolt between the components was also checked. Stress and strain of the components was less than the allowable limits and the yield gap.