COEFFICIENTS OF HEAT AND MASS TRANSFER OF CURRENT-TECHNOLOGY SPRINKLERS FOR PROCESS COMPUTATIONS OF COOLING TOWERS

摘要

Analysis of formulas for computing coefficients of heat and mass transfer derived on the basis of results of laboratory tests of 22 sprinklers is used to show that the classification of sprinklers into film and drop ones can be based on a physically grounded parameter m, i.e., the exponent in the formula for the evaporation number K_(ev) = A_pλ~m (or for the Merkel number Me = A_xλ~m). A generalized formula describing the dependence of the coefficients of heat and mass transfer on the height of the sprinkler is derived, which makes it possible to determine the optimum sprinkler height in cooling tower design. The accuracy of the formulas for computing the coefficients is confirmed by a comparison of experimental and computed values of the temperature of cooled water in the cooling tower of the Novo-Ryazanskaya cogeneration plant.