Numerical Analysis of the Comprehensive Performance of the Shell-and-Tube Heat Exchanger with Different Types of Baffles.

Fock, Zhie Howz (2021) Numerical Analysis of the Comprehensive Performance of the Shell-and-Tube Heat Exchanger with Different Types of Baffles. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

This research study provides an overview of shell-and-tube heat exchangers (STHE) and its underlying problems with segmental baffles. Many researches on the shell-side heat transfer enhancement were conducted with different baffle configurations. Trefoil-hole, helical, flower, trapezoidal, three-zonal and staggered baffles were some examples of the baffle modifications. In this research, segmental (SG), three-zonal (TZ) and staggered (ST) baffles were used to study their effect on the STHE performances. The results obtained were used to compare with each other. Grid independence test, sensitivity analysis and model validation were performed to ensure the constructed STHE models are suit to be used in this study. Validation results showed that the constructed STHE models and the reference model were in good agreement. A total of five test with different designed input parameters was carried out throughout this study, they are test of mass flow rate, number of baffles, baffle cut of STHE-SG model, tube orientation angle of STHE-TZ model and baffle staggered angle of STHE-ST model. The results showed that STHE-ST is the best STHE model as it was able to reduce the pressure drop by an average of 25.48% while only reduce the heat transfer coefficient by an average of 0.29%. Though STHE-TZ can reduce the pressure drop by an average of 79.95% but the heat transfer coefficient also reduced tremendously by an average of 34.68% for all tested mass flow rates which make it less competitive than STHE-ST. The recommended number of baffles to be used in STHE-SG, STHE-TZ and STHE-ST models are six, twelves, and eight baffles respectively. The recommended baffle cut to be adopted in STHE-SG model is 0.45 as it is able to improve the comprehensive performance by an average of 169.72%. Whereas, the recommended tube orientation angle to be adopted in STHE-TZ model is 30° where it gives the highest comprehensive performance as compared to the other tested angles. Last but not least, the recommended staggered baffle angles to be adopted in STHE-ST model is also 30° because it showed the largest improvement of comprehensive performance by an average of 99.92% for all tested mass flow rates.