Numerical modeling of flow and heat transfer in shell-and-tube heat exchangers.

摘要

This dissertation describes a three-dimensional numerical model for simulation of turbulent flow and heat transfer inside shell-and-tube heat exchangers. The simulation is based on a distributed resistance method that uses a modified k-All validations were performed for E type shells. J, F, and H shells can be handled, but were not validated. The model can represent single segmental baffles of any baffle cut and baffle spacing. Double and triple segmental baffles, and disk and donut baffles are not represented in the model. Currently plain tubes in a staggered or inline configuration can be represented by the numerical model. Finned tubes are not modeled. It is assumed that the tubes are clean (no fouling). Single tube pass parallel flow or counter flow arrangements and a U tube bundle are modeled. Multi-tube pass tube arrangement with mixing at the end of a tube pass is not modeled. Further work needs to be done to represent impingement plates. Since all flow calculations performed were in the turbulent regime, effect of property variation on pressure drop and heat transfer was not considered.After validation, the numerical model is used to analyze three dimensional flow, pressure, temperature, and turbulence fields, within shell-and-tube heat exchangers. The computed flow and turbulence fields show a reasonable behavior.