Mathematical Model of the Heat Transfer Process in a Ribbed Pipe of Special Construction

Abstract

One of the types of intensification of heat transfer in heat exchange equipment is the installation of ribs for heat exchange elements. The use of such developed surfaces allows to improve the parameters of heat transfer due to the turbulence of flows and significantly increase the specific heat transfer surface. This study is devoted to the development of a mathematical model of the process of heat transfer of a finned surface of a specific design. The effectiveness of the proposed rib design is confirmed by both experimental research and computer simulation in ANSYS. The mathematical models obtained adequately describe the heat transfer, both under forced and free convection. The proposed models take into account both the convective component of heat transfer and thermal radiation, which allows it to be used for selection, which operates over a wide range of temperatures. The thermal resistance of the heat exchange element takes into account the coefficient of thermal conductivity of the material and the geometric shape of the wall. Particular attention should be paid to the study of the effect of temperature deformations on the wall of the ribbed element. This is especially important in cases of large differences in coolant temperatures in the tube and between the tubes spaces, since the heat exchangers are subject to linear and volumetric deformation. In such situations, the heat exchanger element may lose its elastic equilibrium shape, which may lead to residual deformation and, in some cases, the destruction of structural members. Installation of ribs on heat-exchange elements must be carried out taking into account both the possible temperature deformations and in terms of structural features.

Aerodynamic Drag Study of the Heat Exchange Equipment with Different Fin Geometries

“…In previous studies, the team of authors of this article proposed a model of a new rib design, for which a patent was obtained in Ukraine [19]. In addition, a mathematical model of heat exchange under conditions of forced convection and computer simulation was developed to determine the thermal efficiency of heat exchange pipes with special fins this geometry [20,21]. For a flat plate located perpendicular to the oncoming flow, the resistance coefficient remains unchanged (C X = 2) in different modes of motion because the plate is a poorly streamlined body and flow separation occurs at the edges of the plate, regardless of whether the flow is laminar or turbulent.…”

“…In previous studies, the team of authors of this article proposed a model of a new rib design, for which a patent was obtained in Ukraine [19]. In addition, a mathematical model of heat exchange under conditions of forced convection and computer simulation was developed to determine the thermal efficiency of heat exchange pipes with special fins this geometry [20,21].…”