On the Heat Transfer of a Tubular Water–Water Heat Exchanger and Its Evaluation According to Some Criterial Models.

Since it is known that the results of calculations for various criterial models of convective heat transfer may differ from each other, we compare the experimental data on heat transfer obtained in experiments on laboratory water-to-water tubular heat exchangers with smooth tubes of three different diameters at normal pressure and moderate temperatures with the results of calculations for the criterial models of B.S. Petukhova, S.S. Kutateladze, Nusselt, and M.A. Mikheev. The experiments are carried out on a two-dimensional flow grid of a tube and inter-tube channel, which makes it possible, in accordance with the previously developed method, to construct the longitudinal profiles of the heat-exchange parameters. The results of processing of the experimental data using the method of average values and the longitudinal profiles demonstrate good agreement when compared with each other. It is found that the deviations of the experimental data from the results of calculations using criterial models are systematic in nature; depend on the range of the defining parameters, i.e., the Reynolds and Prandtl numbers Re–Pr in which they are compared; increase with increasing Re number; and, depending on the Pr numbers, have an extremum. [ABSTRACT FROM AUTHOR]