An analytical solution of the problem of limiting intensification of heat exchange in pipes with turbulators for gaseous coolants with variable thermophysical properties for heat exchangers used in the modern construction industry
In this article, an analytical theoretical model has been developed for calculating the limiting values of the average heat transfer in the conditions of its intensification in the pipes of perspective heat exchangers in the construction industry due to flow turbulence for gaseous coolants with variable thermophysical properties. The article developed an analytical modified theoretical model for calculating the limiting values of heat transfer in conditions of its intensification in pipes due to flow turbulence for gaseous coolants with variable thermophysical properties. The analytical model is valid for gaseous coolants with monotonously varying thermophysical characteristics. The analytical model describes the corresponding processes for a wide range of Reynolds and Prandtl numbers, which makes it possible to more accurately predict the reserves of intensification of nonisothermal heat transfer. The most important conclusion regarding the results of the theoretical calculation of the limiting heat transfer obtained in the framework of this study is the relative practical insignificance of the effect of non-isothermicity on the averaged limiting heat transfer, since the temperature differences used in modern heat exchangers of modern construction production are generally relatively small. The analytical mathematical model is valid for gaseous coolants with monotonously varying thermophysical characteristics. The analytical model describes the corresponding processes of intensified teleexchange for a wide range of Reynolds and Prandtl numbers, which makes it possible to predict the reserves of intensification of non-isothermal heat exchange, including in promising tubular heat exchangers with enhanced heat exchange for modern construction production. Based on the results of analytical calculations of the limiting non-isothermal averaged heat transfer based on the mathematical model developed in the article, it is possible to further simulate thermal characteristics for promising heat exchangers in the construction industry. The analytical model describes the corresponding processes for a wide range of determining parameters, which makes it possible to predict the reserves of heat exchange intensification for heat carriers with variable thermophysical properties in those areas where reliable experimental data are not yet available. Previously, the solutions to this problem were only numerical, valid only for a limited defining range, so the analytical solutions obtained in this work have a certain advantage over them.