CFD based Performance Analysis of Counter Flow Heat Exchanger using Various Turbulent Models

An extensive computational thermodynamic analysis of counter flow heat exchanger (CFHE) under numerous operating and geometric conditions is presented in this paper. A three-dimensional heat exchanger model of 100 cm length and 1.27 cm diameter is designed in ANSYS 14.0 using different turbulence models to analyze the heat transfer. Moreover, the computational results are compared with existing experimental data [8]. With changing flow direction, the heat exchanger yields a better result with an average computational error of 1.140% in RNG k-ε while step changing the cold fluid temperature and 0.403% while altering the hot fluid temperature. Similarly, by applying k-ω Std. and SST, the average error for the cold fluid temperature variation is 1.233% and 1.288%, respectively. In addition to that, for varying hot fluid temperatures, the average error to be 0.786% and 0.789%, respectively. The outcome of all the results shows the RNG k-ε model predicts better performance of the heat exchanger (HE). Introduction Today's demand for higher energy consumption and reduced availability of fossil fuel resources increases the impact of the effectiveness of heat exchanger gradually. These heat exchangers are broadly used in the industries and energy conversion systems. Heat exchangers are very effective for the transfer of heat from one medium to another without even intermixing of one fluid with another. Typically, in a heat exchanger, two segregated fluids at different temperatures with a solid boundary exchange thermal energy from one fluid to another via surface without even intermixing.