Topic > The Properties of Heat Transfer: Chang and Guo - 705

Heat transfer enhancement mechanisms due to a twisted ribbon include:(1) a reduction in hydraulic diameter which causes an increase in flow velocity and curvature which in turn increases shear stress on the wall and drives secondary motions, (2) increased fluid mixing between the core and flow regions near the wall, and (3) additional heat transfer through the thermal contact, probably. A high cost of energy and material has resulted in greater focused effort in producing more efficient heat exchange equipment. Methods for improving convective heat transfer in boiler tubes have been extensively studied by many researchers. Spiral insert or ribbon insert is one of the heat transfer enhancement techniques classified as passive technique. In this study, the author will focus on the perforated type of twisted tape insert and how it affects the improvement of heat transfer. Chang and Guo (2012) studied the heat transfer properties during development and the developed flow regimes, pressure drop coefficients, and thermal performance factors (TPFs) of tubular flows with continuous and pointed twist tapes enhanced by perforated, jagged and serrated fins. It is established that among the twisted tape types examined in the study, V-notch pointed twisted tape offers the greatest heat transfer enhancement impact with favorable TPF performance. Nanan et. al (2014) experimentally studied twisted perforated helical tape on heat transfer, friction loss and thermal performance characteristics under uniform heat flow conditions. From the experiment result, they found that helical twisted perforated tape contributes to the reduction of f...... half of the paper ...... bee insert on the characteristics of heat transfer, friction loss and performance factor thermal in a round tube. The results show that both the heat transfer rate and the friction factor in the tube equipped with peripherally cut twisted ribbons were significantly higher than those of the tube equipped with the typical twisted ribbon and the smooth tube, especially in the laminar flow regime. From all the article discussed above, it is established that serpentine plate inserts in tubular heat exchange equipment significantly improve the heat transfer rate of the system. However, there is scope for improvement that can be made through this project. Therefore, the main objective of this project is to further improve the heat transfer rate of the system by implementing (punched) holes on the battery plates. Experimental investigations will be conducted to obtain new results and discoveries through this technique.