Study on Vibration and Thermal Expansion of Heating Furnace Manifold Based on Fluid-Structure Interaction Method

Abstract

In the petrochemical industry, the manifolds are usually adopted as the distributor of the heating furnace. The structure of the manifold plays a crucial role in the safe operation of the heating furnace. For the straight tube structure and fishbone structure of the manifold, thermal expansion calculation was carried out in this paper. The expansion amount of each branch pipe was obtained, and the maximum expansion amount of the branch pipe was 91.8% of the reserved size. The accuracy of the design of the branch pipe wall clearance allowance was verified. Numerical simulations of the fluid-structure interaction were carried out for both structures, which showed that the two structures have similar deformation and frequency in terms of overall structural vibration. However, in the branch vibration, the stress and vibration frequency of the fishbone branch increase by 12.6% and 25.3%, respectively, compared to the straight tube branch, which is caused by the presence of large vortices in the branch of the fishbone structure. Finally, modal analyses were performed for both structures, and the results can be used to estimate whether the vibration frequencies of the two structures avoid the natural frequencies.