International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 09 Issue: 08 | Aug 2022 www.irjet.net p-ISSN: 2395-0072 © 2022, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 1182 HEAT TRANSFER ANALYSIS OF EFFECTS OF LONGITUDINAL FINS ON HEAT TRANSFER IN DOUBLE PIPE HEAT EXCHANGER Abhinab Nath 1 , Rangina Brahma 2 1 UG Student, Department of Mechanical Engineering, SRM College of Science and Technology, Tamil Nadu, India 2 Ph.D. Scholar, Department of Food Engineering &Technology, Central Institute of Technology Kokrajhar, Kokrajhar, BTAD, Assam:783370, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Heat transfer enhancement, also known as heat transfer augmentation, refers to a variety of methods for improving heat transfer's overall effectiveness. Heat exchangers equipped with heat transfer enhancement methods are referred to as "Augmented Heat Exchangers. "The primary objective is to reduce the maximum number of factors as possible be it Maintenance Cost, Power Cost, Capital Cost, Space and Weight, Consistent with increased safety and reliability. Heat transfer augmentation techniques are commonly used for cooling and heating in condensers, evaporators, thermal power plant, air-conditioning equipment, space vehicle, automobile etc. In the current paper, which deals with heat transfer analysis of double-pipe heat exchangers using longitudinal fins, the key industrial approaches are covered. Heat transfer is analyzed and its performance is found comparatively best with plain double pipe heat exchanger of same equivalent diameter pipe of internal and external. The results showed that using a longitudinal fin arrangement is beneficial for improving the LMTD's overall heat transfer and efficacy, which are shown to have increased by 28.42 watts, 12.5 watts, and 0.0322 watts correspondingly. Key Words: Double Pipe Heat Exchanger, Heat Transfer analysis, Longitudinal Fins, LMTD, Heat Transfer Augmentation, Heat Transfer, Heat Exchanger 1.INTRODUCTION The science of system heating and cooling is one of mechanical engineering's most essential subfields. Every time steam is needed or when hot or cold fluids are required, a heat exchanger is installed. They are installed in order to heat and cool residences, workplaces, marketplaces, retail centres, automobiles, trucks, trailers, aeroplanes, and other forms of transportation. They are employed in numerous industrial processes including in the processing of food, paper, and petroleum. They can be found in advanced computer systems, fusion power laboratories, spacecraft, and superconductors. Both in low-tech and high-tech industries, the possibilities are nearly limitless. Since the functioning of the heat exchangers has a significant impact on the process' economy and efficiency, heat exchangers have been employed in industrial processes. Therefore, high performance heat exchangers are often desired. The size of the heat exchanger could be reduced as a result of improved performance. As an alternative, a high efficiency heat exchanger of a specific set size can enhance the heat transfer rate and/or reduce the temperature difference between the fluids, allowing for the effective utilization of thermodynamic availability. Research and development to improve heat transfer equipment design has seen tremendous growth as a result of the current imperative to preserve energy and materials. 2. LITERATURE REVIEW Thomachan et al., (2016) found out that as pitch length of the fins increases with constant depth effectiveness of the heat exchanger also increases. According to the simulation of a finned double pipe heat exchanger and the findings, finned configurations exhibit generally better thermal properties than configurations without fins (Shiva Kumar et al., 2015). The annular approach achieved higher heat transfer than other ways, according to the experimental and analytical findings about the heat transfer loss and gain by hot and cold fluid (Kannan et al., 2012). Patel et al., (2013) concluded that the heat transfer rises linearly with the increase in mass flow rate for heat exchangers with and without fins. Jalay R Soni et al., (2015) concluded that the dimpled inner tubes transmit heat more quickly than the normal tubes. Monica et al., (2015) revealed that the thermal properties of rectangular finned designs are generally improved. Sreenivasalu et al., (2017) describes that at various intake temperatures and mass flow rates, the annulus side of a concentric pipe heat exchanger's characteristics of heat transfer are shown, and it is noted that the heat transfer rate and the coefficient of heat transfer, directly depend on the mass flow rates of the hot and cold fluid. Kailash et al., (2015) states that the overall coefficient of heat transfer utilising semi-circular fins reduces by more than 300% for Re=17161.05, indicating significant increases in the total heat transfer area.