Heat Transfer 01

    
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Heat Transfer Finite Element Analysis:
Perform both transient and steady state heat transfer analyses on a large, industrial, process, piping system carrying a heated, flowing slurry.

Special features:
3D model setup with 3D plates and bricks.

Output:
Temperature.

Comments:
The finite element model was very large. The mesh was complicated because the pipe was made from three layers, two metal layers and one insulation layer and support structures that passed through the insulation at several locations. Clicking on the thumbnails will bring up larger views. The 2nd thumbnail shows a complex intersection of a smaller, feed pipe with the larger pipe. This tie-in was meshed using Autodesk's PVDesinger. Heat conduction was the primary heat transfer mechanism. Internal radiation and convection were contemplated as well. The entire analysis was targeted toward a worst-case temperature gradient determination based on the best surmised heat flux conditions to be used later for a stress evaluation, the real concern. The equipment was exposed to the weather in a very cold climate. Since the interior was at a hot extreme, the exterior was set to a cold extreme temperature with a wind, from which a worst-case external film coefficient was calculated. Internal body-to-body calculations were used in a 2D model to estimate view factors for the larger 3D model. Using the internal generator to calculate all interrelated views of the 3D model (9000+ element faces) would have required approximately 14, 24-hour days to calculate.

The 2D assumption was valid since the piping system was long with respect to its diameter. The 2D calculation basis allowed a 3D solution of the big model that took only a couple of hours to complete in the steady state mode. The last two thumbnails show some results (the outside insulation layer is hidden in these views - pay careful attention to the legend and what is and what is not plotted in order to pick out temperatures).