| Shell-and-tube heat exchangers are universal equipments in many industrial fields. In recent years, because of factors such as process requirements, energy crisis etc, it has become a hot topic to research heat transfer enhancement.Research and develop the longitudinal supporting structures is one of the important aspects. Many supporting structures like ROD baffle, flat steel bar, and ring have been utilized. These structures have many advantages of higher heat transfer efficiency, lower flow resistance, etc. But, in the case of lower Reynolds number, the fluid on the shell-side cannot be developed to a full turbulence, so the heat transfer efficiency is worse than that of higher Reynolds number.The correctness of using periodic unit duct model to simulate the shell-side flow and heat transfer is confirmed for the first time, when using the corrugated tube. Meanwhile, the accuracy of numerical simulation results is verifiedBased on the confirmation, FLUENT software is employed to simulate the shell-side flow and heat transfer of compound structures of both corrugated and smooth tubes to ROD baffle, flat steel bar and ring. The detailed analysis of flow and heat transfer is carried out and the comparison of heat transfer efficiency between corrugated and smooth tubes are obtained. The results approve that, the combination of corrugated tubes to supporting structures can effectively enhance the heat transfer efficiency, and is better than that of smooth tubes.Therefore, using the combination of corrugated pipe to supporting structures can enhance the shell-side heat transfer efficiency; it can be used to improve the heat transfer effect using smooth tubes in the case of low Reynolds number. Thus, the application scope of these supporting structures will be widely expanded. The simulation results of this dissertation can provide a guide to the application of the supporting structures and corrugated pipes. |
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