Modeling and CFD Analysis of Tube in Tube Helical Coil Heat Exchanger

A helical coil heat exchanger has a wide range of application in industries over the straight and shell type heat exchangers because of its greater heat transfer area, mass transfer coefficient and higher heat transfer capability, etc. The relevance of helical coil heat exchanger has been identified in industrial application like turbine power plants, automobile, aerospace, etc. because of above mentioned factors. In this thesis we model a tube in tube helical coil heat exchanger using CATIAV5r18 and done CFD analysis using ANSYS. The thesis shows the deviation of Nusselt Number for different curvature ratio (/ ratio) and Reynolds Number. CFD analysis has been done for varying inlet condition keeping the heat flux of outer wall constant. The turbulent flow model with counter flow heat exchanger is considered for analysis purpose. Copper was used as the base metal for both inner and outer pipe and simulation has been done using ANSYS 13.0. The software ANSYS 13.0 was used to plot the temperature contour, velocity contour. pressure contour taking cold fluid at constant velocity in the outer tube and hot fluid with varying velocity in the inner one. We also find out the wall shear stress on both inner and outer tube. Water was taken as the working fluid for both inner and outer tube. Result after analysis shows that temperature, pressure velocity contour in the heat exchanger were similar to literature data and It is also visible from the results that Nusselt Number depends on curvature ratio. It is increasing with increase in curvature ratio. In addition, the value of Nu no. was found to increase with increase in mass flow rate (i. e. inlet velocity), With increases in D/d ratio (inverse of curvature ratio) the Nusselt number will decreases, for a particular value of Reynolds number. Nusselt number has maximum value for D/d=10.