【摘要】 对热湿交换过程进行质量与能量衡算,建立逆流板式蒸发冷却器传递过程的微分方程组。借鉴Braun的方法,引入空气湿球比热与湿球换热系数,对湿空气饱和线作线性化假设,推导得到了基于空气湿球温度的数学模型和控制微分方程组的解析解,实测结果验证了解析解对流体出口温度预测值的准确合理性。分析循环热水温度、喷淋水温度、空气干湿球温度的变化规律,以及空气进口干湿球温度对冷却器性能的影响。该分析模型与解析解可用于预测板式蒸发冷却器的性能。更多还原

【Abstract】 The heat and mass conservation differential equation group in the counter-flow plate evaporative air coolers is developed. Based on the Braun method, the specific heat capacity and heat transfer coefficient of wet bulb are introduced for linear assumption of the moist air saturation line. A new mathematical model of heat and mass transfer processes is proposed. The analytical solutions are deduced based on the wet bulb temperature and control differential equations. The model consists of four ordinary differential equations with their boundary conditions. The variation rules of temperature distributions of the re-circulated water, spraying water, and moist air along the height of evaporative cooler are analyzed. Effects of dry and wet bulb temperature of inlet air on cooler performances are discussed. The outlet temperature predictions of air and hot water and spraying water are found to agree with the measured results. This model and analytical solution can be used to predict the performances of plate evaporative coolers.更多还原