Heat Transfer and Stress Analysis of Coke Drum for a Complete Operating Cycle

Coke drums experience severe thermal and mechanical loadings during operation, and the reliability and safety of the coke drums are critical to the industry. The objective of this study is to analyze temperature and stress of the coke drum for a complete process cycle. The thermal analysis model of the coke drum is first developed incorporating appropriate boundary conditions. The heat transfer coefficients at the inner surface of the coke drum, which change with the operation stages and the levels of oil filling and water quenching, are determined based on the temperature measurement data at a certain location on the outer surface of the coke drum. The temperature history of the coke drum of a complete cycle is then obtained by finite element heat transfer analysis, and computed temperature data are used for the stress analysis of the coke drum, including both thermal and mechanical loadings. It is found from numerical results that the clad experiences a biaxial stress cycling with maximum value higher than the yield limit of the material, which coincide with the low cycle fatigue failure of the structure.