Seismic finite element analysis of passive rectangular heat pipe heat exchange tank in nuclear power plant

Abstract

In this paper, an efficient and simple three-dimensional finite element seismic analysis method for rectangular ventilation heat exchange tank of nuclear power plant is proposed. Firstly, the liquid sloshing effect is simulated by the layered mass-spring model, and the liquid sloshing effect of three diameter methods under the simplified model of Housner and IITK-GSDMA is compared and analyzed. Secondly, in order to improve the analysis efficiency and maintain the key dynamic characteristics of the model, the three-dimensional calculation model is reasonably simplified by using the technology of intermediate surface extraction and beam extraction, and a fine three-dimensional finite element model is constructed which can capture the subtle stress changes under the action of seismic loads. Finally, the natural frequency of the rectangular tank is determined by the finite element modal analysis method, and the stress and strain of the rectangular tank under the actual seismic load is predicted by the response spectrum analysis method. The results show that the first-order shaking frequency calculated by the equal area diameter method based on Housner simplified model is consistent with the first-order shaking frequency simulated by the finite element method, which verifies the reliability and convenience of using the equal-area method to simplify the finite element seismic analysis of the rectangular water tank. This method can accurately and quickly predict the dynamic response of liquid under earthquake action, and provides a more scientific and reliable analysis means for seismic design and risk assessment of rectangular water tank, effectively improves the safety and reliability of rectangular water tank, and provides a strong support for the seismic design of key facilities such as nuclear power plants.