| Summary: | 碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系碩士班 === 105 === In recent years,the issue of saving energy and carbon reduction has been paid more and more attention. The heat exchanger is based on the heat transfer between the fluids to achieve the purpose of reducing the load. Plate fin-and-tube heat exchagers are widely used in several areas, such as heating, ventilating, air conditioning and refrigeration system. However, the geometries of plate fin and tube heat exchanger influence the flow field characteristics greatly and are the main reason for determining the effectiveness of the heat exchanger. In this study, the heat transfer performance and pressure drop of the air side are simulated by using Computational Fluid Dynamics,CFD. The turbulence model is simulated by k-ω and the simulation results are compared with literature. According to the comparison of results, the reasonable agreement is found between the simulation and experimental data, revealing the accuracy of the CFD simulation. For the purpose of optimizing heat exchanger, this research use Taguchi analysis to find the optimal combination of parameters. The geometrical parameters that affect the performance of the heat exchanger, such as tube arrangement, longitudinal pitch, transverse pitch and fin pitch. The increase in the longitudinal pitch and transverse pitch causes a decrease in the heat transfer and pressure drop performance as the flow becomes less compact. The effect of fin pitch on the heat exchanger shows the opposite performance to that of the longitudinal and transverse pitches. According to the results, the optimal combination of parameters is the in-lined configuration, the longitudinal pitch of 38.1mm, the transverse pitch of 35.4mm, and the fin pitch of 1.53mm.
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