Modeling of the Fire Tube Failure in a Heat Exchanger

Abstract

The equipment used in the oil distillation and processing industry operates under highly demanding conditions and increasing requirements. Heat exchangers separate water from oil and include fire tubes where combustion gases generate the necessary temperature for the separation process. This study analyzes the structural response of a fire tube that exhibits significant deformations on a localized sector near the burner, aiming to identify the causes of its failure. Failure analysis allows for the improvement of working conditions and contributes to preventing production interruptions. A previous metallographic study of the material revealed excessive grain growth consistent with exposure to high temperatures in the damaged area. The fire tube is modeled with solid finite elements, and the steel's mechanical properties with temperature variation are also considered. We conduct a geometric nonlinear analysis, including material plasticity, to replicate the failure mechanism. The study demonstrates the need to monitor the tube's thermal distribution to avoid areas of high-temperature concentration.