Failure Analysis And Multi-physical Simulation Of Steam Cooling Coiler

Fatigue failure occupy80%in the failure causes of chemical steam pipes, which bring heavy losses to factories and enterprise in economic benefit and social effect. In this thesis, the steam cooling coiler of3#catalyticcrackingunit from Sinopec Shanghai Gaoqiao Company is studied.Given the widespread failure position and the failure form, the failure mechanism of this kind of coils was explained in this paper, thus providing a theoretical basis for the design and optimization of this kind of coils.Through Macro crack check, fracture SEM analysis, element component analysis and metallographic analysis of failure coiler according to coil operation monitoring data and actual operation condition, it is deduced that the primary cause of coiler perforation is corrosion thermal fatigue damage. The steam coiler’s coupled fluid-solid-thermal3-D field model, which is built in Fluent software, makes the impacts of flow field and oxidation film on temperature field into consideration. Steam coilerwall’s temperature field and steam flow field of at7different operation conditions are simulated and calculated. The way pipe wall’s temperature change with flow and pressure is obtained. And figure out how the vortex pair impact the flow field and the tube wall temperature. In ANSYS analysis, steady state analysis of the pipe wall stress in6different flow has been conducted based linear elastic theory. It is obtained that the main reason why the lifetime of the coils decreases sharply after steam flow increases.Experimental method and computer simulation are applied to analysis failure reason of steam coiler in this thesis. This kind of coiler failure mechanism is obtained scientifically. It has remarkable value to steam coiler’s design and optimization in next.