Abstract

The scientific and technical problem of calculating the transfer of momentum, heat and mass of water vapor in cooling towers has been solved theoretically using a turbulent boundary layer model in the gas phase for irrigated packing blocks. A dissipative mathematical model for determining the average tangential friction stress at the gas–liquid interface in film contact devices (sprinkler blocks) with intensifiers is considered. On the basis of the average rate of dissipation of the energy of the gas flow in the sprinkler blocks with a given law of damping of turbulent pulsations in the boundary layer, expressions are obtained for calculating the average values at the interface of the shear stress and dynamic velocity necessary to calculate the coefficients of heat and mass transfer in the gas phase. To calculate the heat and mass transfer coefficients, expressions obtained earlier by the authors are used which are associated with the hydromechanical characteristics of a turbulent boundary layer. To determine the characteristics of the boundary layer with intensifiers on contact film devices, the properties of the conservatism of the laws of friction and heat transfer to perturbations are applied. Perturbations do not change the form of the mathematical description of the transfer of momentum and heat, and perturbations are taken into account parametrically. As a result, expressions are obtained for the Nusselt and Sherwood numbers for contact devices of various designs. Numerous comparisons of the results of calculating the coefficients of heat and mass transfer for chaotic and regular packings (sprinkler blocks) with known experimental data are shown. The expressions can be used in the calculations of sprinkler film blocks using hydraulic resistance, which reduces the time and costs in the design of cooling towers.

中文翻译：

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带增压器冷却塔喷淋头薄膜装置相分离和传热传质表面摩擦的数学模型

摘要

使用气相湍流边界层模型，从理论上解决了计算冷却塔中水蒸气的动量、热量和质量传递的科学技术问题，用于灌溉填料块。考虑了一种耗散数学模型，用于确定带增强器的薄膜接触装置（喷淋块）中气液界面处的平均切向摩擦应力。根据给定边界层湍动脉动阻尼规律的喷淋块内气流能量的平均耗散率，得到了计算剪应力界面的平均值的表达式和计算气相传热和传质系数所需的动态速度。为了计算传热和传质系数，使用了作者之前获得的表达式，这些表达式与湍流边界层的流体力学特性相关。为了确定接触膜装置上具有增强器的边界层的特性，应用了摩擦和传热定律对扰动的保守性。扰动不会改变动量和热量传递的数学描述形式，并且会以参数方式考虑扰动。结果，获得了各种设计的接触装置的 Nusselt 和 Sherwood 数的表达式。显示了计算混沌填料和规则填料（喷淋块）的传热和传质系数的结果与已知实验数据的大量比较。这些表达式可用于使用液压阻力计算喷淋膜块，从而减少冷却塔设计的时间和成本。