Predictions of heat transfer correlations for helically coiled tube-in-tube heat exchangers

A method which allows numerical calculations unknown parameters in correlation formulas for Nusselt number and calculations of heat transfer coefficient was presented. The values of unknown parameters and heat transfer coefficients were determined on the hot and cold fluid side simultaneously with-out necessity of prior indirect calculations of overall heat transfer coefficient. Calculations were carried out on the basis of experimental data for parallel and counter flow in helically coiled heat exchanger CCX14 tube in tube type. As a result of numerical calculations distributions of Nusselt number versus of Reynolds number in circular and annular channel were presented.