Heat Transfer In Heat Exchanger

678 Words3 Pages
LITERATURE REVIEW 2.1 Introduction Increased the convective heat transfer in heat exchangers with passive techniques has been a subject of interest to scientists and researchers during the last decade. Numerical and experimental review were reported to increase the amount of heat transferred by these techniques. Review of the literature on the techniques of passive heat transfer augmentation focused on the nature of the winglet in different applications. The need to reduce costs, dimensions and save energy for heat exchangers has been boosted across various heat transfer enhancement techniques. Studies conducted using one of passive heat transfer augmentation techniques are the winglets. Insert type was evaluated and examined by various investigators to increase the rate of heat transfer in the channel. Figure (2) displays the type of longitudinal vortex generators. Figure-2-type longitudinal vortex generators; From top to bottom respectively delta wings, the rectangular wings, a pair of delta winglet and winglet pair of rectangular [8]. Thermo hydraulic the performance of of the insert is measured by reference to the ability to increase the heat transfer coefficient with the a minimum increase in the friction factors. Install the heat exchanger tubes was used for years as reliable way to increase heat transfer and fouling mitigation in petroleum refineries and chemical plants. This chapter, the literature review classified into: 2.2. Applications of winglet vortex generator There are several types of winglets have been used in many applications such as solar water heaters, heat exchangers and cooling systems. Experiments on heat transfer enhancement in a tube using a winglet has been widely reported. Ahmed et a... ... middle of paper ... ...e T-W-wing statement gives the heat transfer rate is higher than a rear wing with around 7%. It also found that the rate of the transfer of heat and a friction factor derived from T-WA was higher than the T-W. 2.2.2 Winglets in non-Circular tube (channel or duct) Akcayoglu [11] review the experimental flow of the structure in the horizontal channels an equilateral triangle with two rows of vortex generators half delta-wing type. Every channel consists of two rows of trees half-delta wings are arranged either in normal or normal stream flow configuration down. The Reynolds number was changed 1000-8000. A secondary differences flow field generated by two of different vortex generator configurations were examined in detail. The secondary flows were more behind vortex generators pair of second behind the first pair but a weak away from the second pair in case Duct1.
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