Author : K.Sainath, Yogendra BrijMohan Rathi and T.K.K Reddy

The heat exchanger is a device used for the process of heat exchange between two the fluids at different temperatures. The heat exchange process in heat exchangers can be described by the principles of conduction, convection, radiation and evaporation or condensation. Heat exchangers are useful in many engineering processes like those in refrigerating and air conditioning systems, power systems, food processing systems, and chemical reactors. Heat transfer and thermal stresses, induced by temperature differences in the internally grooved tubes of heat transfer equipment, have been analyzed numerically. The analysis has been conducted for four different kinds of tube material like aluminum (Al), cast iron (C.I), brass (Br), copper (Cu) and steel (St). Constant temperature was applied from the external surface of the tube and inlet outlet water temperatures and constant fluid to wall heat transfer coefficient was applied for the estimation of thermal profiles. These thermal results are incorporated for the estimation of Vonmises stress distribution. Energy and governing flow equations were solved using finite different schemes. Finite Element Method (FEM) was used to compute the thermal stress fields. Different materials on the thermal stress values have been discussed. As a result, maximum thermal stress occurs in the aluminum material because of high thermal conductivity of that material. Thermal stresses are directly depends on the thermal conductivity of the material. The maximum thermal stress ratio positions inside the tube have been indicated as MX for all investigated cases. Maximum thermal stress values are obtained at top surface of the groove for all the materials.

Keywords: Heat transfer, thermal stress, grooved tube, different materials and FEM.

Article published in International Conference on Advances in Mechanical Sciences 2014, Special Issue-2 (Feb 2014)