Heat exchanger with semi-circular tubes and mountings for effective heat transfer

AbstractCompact heat exchangers are widely being used in various devices owing to its minimized size and efficient operation. The traditionally fitted circular tubes in heat exchanger have been modified as semi-circular tubes with slit. This newly proposed design offers added tubes surface area of 63.69% for better fluid flow and heat exchange. To investigate, two dimensional, unsteady, incompressible and isothermal computational studies have been carried out. The different confinements (BR= 1.54d, 2d and 3d) and gap ratios (g = 0.07, 0.14 and 0.21)have been preferred in order to mimic confined fluid environment in compact heat exchangers over the Reynolds numbers range of 50-200. Ansys Workbench 18 has been employed in modeling, meshing and carrying out the simulations of the problem formulated. Pressure and velocity were coupled using the SIMPLE algorithm. The convective and diffusive terms in the governing equations were discretized using second order upwind and central difference scheme. The time step size was fixed as 0.005 and the simulation was run until flow maturity. Results claim that flow sheds well nearer to tubes with slit at BR 1.54, which is not happening for circular tubes at same BR. The arrangement with the minimum BR and maximum gap ratio offers best performance. Semi-circle combination separated by 0.21d offers best heat transfer with an improvement of 10.51% as compared to circular components at a blockage (BR) ratio of 1.54 and Re of 200.The concept of tube splits instead of circular tubes is more effective in dissipating heat whenever the flow shedding is deteriorating or completely eliminated. The overall performance parameter (ɛ) for tube split is highest when BR 3 and g 0.21.Keywords: Computational fluid dynamicscondenserconvection heat transferfluid mechanicsheat exchangersemi-circular tubes Disclosure statementWe confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us.AcknowledgmentsWe would like to thank Product Development Laboratory at SRM Institute of Science and Technology for providing us resources and other services without which this study would not have been possible.