International Journal of Engineering Research and Technology. ISSN 0974-3154, Volume 12, Number 12 (2019), pp. 2587-2591 © International Research Publication House. http://www.irphouse.com 2587 Experimental Study of Heat Transfer in Conical Tube Heat Exchanger Chirag Maradiya 1* , Dr. Jeetendra Vadher 2 and Dr. Ramesh Agarwal 3 1Department of Mechanical Engineering, L.E.College-Morbi, GTU, Gujarat -363641, India. ORCID: 0000-0001-9730-8690 (Chirag) 2 Department of Mechanical Engineering, GEC-Palanpur, GTU, Gujarat -385001, India. 3 School of Engineering and Applied Science, Washington University in St.Louis, USA. Abstract In present experimental analysis, the outer cylindrical tube of the ordinary concentric tube type heat exchanger was replaced by conical tube. New conical tubes of different diameter ratios have been developed by using epoxy resin and glass fiber. Diameter ratios of conical tubes were 0.882, 0.741, and 0.612. Experiments were carried out for conical tube heat exchanger of length 1 meter. The flow rate of water for inner tube considered 1LPM and for outer conical tube 1 LPM to 7 LPM. The heat transfer results of conical tubes were analysed and compared with the results of cylindrical tubes. Results reveal that the rate of heat transfer is inversely proportional to diameter ratio. A correlation was developed for a HTR of water flowing through outer conical tubes. Results revealed a rise of heat transfer rate up to 22%. Keywords: conical tube, heat transfer, regression analysis, heat exchanger I. INTRODUCTION Heat transfer equipment is required for the exchange and recapture of thermal energy in many commercial and household appliances. Few industrial applications i.e. heating and cooling of dairy products, heat recovery system, processing of juice as well raw fruit in food industries, power plant’s vapor condensation process, heat transfer processes involved in chemical and pharmaceutical companies, Liquid heating in the concentrated solar collector and cooling of electronic devices and electrical equipment among others. Therefore, to ensure the economy of cost & energy, efficient functioning of heat transfer equipment is of prime interest. Thermal resistance is inversely proportional to effective surface area & turbulence of fluid. Majority of heat transfer improvement methods focuses on reducing thermal resistance by using fins/rough surfaces for improving effective surface area & inserts, winglets, etc. for ensuring turbulence within the fluid.[1]. The heat transfer enhanced significantly when coil-wire was inserted in the inner tube. Naphon[2] observed that the coil- wire performed better, especially for the laminar region. Eiamsa-ard et al. [3] experimentally analyzed the heat transfer properties in heat exchanger having concentric tube arrangement equipped with twisted tape which are regularly spaced. Their results revealed that rise of the heat transfer co- efficient is directly proportional to twist ratio. Selvam et al.[4]conducted experiment having turbulator like Wire coiled-matrix used as an insert in the tube - tube heat exchanger. Their study revealed that a reduction in the pitch has a positive influence on the rate of heat transfer (HTR). Eiamsa-ard et al.[5] experimentally examined the HTR by commissioning louvered strips inside the double tube heat exchanger. Experimental results revealed that the application of inclined forward louvered strip rises the HTR by 2.84 to 4.13 times. Pourahmad and Pesteei [6]conducted experiments on the concentric tube heat exchanger in which wavy strips have been inserted at various angles to rise the HTR. It has been perceived that the performance of the heat exchanger improves with strip angle. Murugesan et al. [7]analyzed twisted tape with a trapezoidal cut on the periphery and observed the characteristics of heat transfer. From the results conclusion has made that, the HTR increase from 1.2 to 2 times for different configuration of twisted tape. Shirvan et al.[8]analyzed the effectiveness of double-tube heat exchanger by mathematical model. They used nanofluid to enhance heat transfer and Response Surface Methodology to sensitivity analysis. Sheikholeslami et al. [9] conducted experiments to confirmed the outcome in terms of the HTR with use of discontinuous helical turbulators in tube-tube heat exchanger. Typical and perforated helical turbulators placed on the annulus side of the tube to enhance the HTR. Li et al.[10] studied the effectiveness of double tube heat exchanger in which helical fins were attached on the shell side along with vortex generators. Their results revealed that the compound technique has better performance than the shell side only attached with helical fins. Webnin et al. [11] introduced the small pipe insert placed consecutively in a concentric tube heat exchanger. The result of the experiments revealed that the HTR enhanced by 2.09-2.67 times with pipe inserts. Dizaji et al.[12] used a corrugated outer tube instead of a straight cylindrical tube. The experiments were conducted with Reynold number ranging from 3500 to 18000 and results reveals that maximum effectiveness obtains with outer tube as concave corrugated and inner tube having convex corrugated shape. Heat transfer rates in a double tube heat exchanger equipped with wire coil inserts in annulus space have been analyzed by Zohir et al.[13]. They investigated the influence