Parameter optimization in PCM based heat exchanger for pasteurization process

Abstract

The concentric double tube heat exchanger is widely used for many newlineapplications. The heat transfer fluid, i.e. water passes through the inner tube. newlineThe fluid is to be heated up, passes in the outer tube (annulus). The heat newlinetransfer augmentation is widely studied in various aspects. The augmentation newlinetechniques broadly classified as active, passive and combine techniques. The newlineactive techniques involve major modifications, but passive techniques involve newlineminor modifications. During this investigation the amalgamation of three newlinedifferent technologies to amplify as well as control the desired process. The newlinenanotechnology concept of use nanofluid to augment heat transfer considered newlineinstead of water in the concentric double tube heat exchanger. Four different newlinenanofluids considered with use of titanium dioxide, beryllium oxide, zinc oxide newlineand copper oxide. The pumping loss is an important constraint in heat newlineexchanger so in order to achieve minimum pumping loss the low weigh newlinepercentage of 0.04% preferred. Hence the heat transfer fluids like water, newlinetitanium dioxide water nanofluid, beryllium oxide water nanofluid, zinc newlineoxide water nanofluid and copper oxide water nanofluid considered in the newlineinvestigation. The next concept of heat transfer augmentation of improving the newlinesurface area by offering the tube inserts. The four different tube inserts newlineconsidered. In order to increase the fluid mixing and improve turbulence the newlinerectangular and trapezoidal shaped cuts preferred on the ribs of the twisted tape newlineinsert. In this research twisted tape with rectangular cuts on its ribs referred as newlineinsert-1 and twisted tape with trapezoidal cuts over the ribs referred as an newlineinsert-2. The circular fin insert and spiral spring insert are referred as insert-3 newlineand insert-4. The width of the insert is maximized to support for heat transfer newlineaugmentation. The computational model geometry and the grid were generated newlineusing SOLID WORKS, The preprocessing module for the ANSYS FLUENT newlinesoftware version 15.0 is used for this numerical investigation. The insert and newlineheat transfer fluid combinations experimented and optimized them initially newline