蜂窝式除湿转轮的传热传质数学模型及其试验验证

HEAT MASS TRANSFER MODEL OF A HONEYCOMBED ROTARY DESICCANT WHEEL AND EXPERIMENT

针对蜂窝式除湿转轮的结构特点以及波纹形通道的传热传质特性,建立了转轮除湿过程中的传热传质数学模型,用试验数据验证了其合理性。分析和讨论了传热传质过程中空气温湿度和干燥剂温度及其含水量的分布情况和特征。数值计算发现:在波纹形通道内沿再生空气方向存在一条空气含湿量峰值线,该峰值线向出口方向的迁移时间和峰值的大小决定了再生速度和再生效率。为了提高再生效率,应该尽可能加快再生空气含湿峰值向出口处的移动过程,提高其迁移速度,降低迁移时间。最后还对运行参数对再生空气出口含湿峰值的大小及其迁移时间的影响进行了讨论。

Based on the practical structure of the honeycombed rotary desiccant wheel and the nature of heat and mass transfer in the sinusoidal corrugated air duct, a one-dimensional coupled heat and mass transfer model, which is expected for use in designing and manufacturing of a honeycombed rotary desiccant wheel, is presented. The mathematical model has been validated experimentally with a real desiccant wheel. It is found that the calculation results are in reasonable agreement with the experimental data. Based on this model, the temperature and humidity profiles in the wheel during both the dehumidification and the regeneration processes are analyzed and verified by experimental results. The numerical results indicate that in the regeneration process a hump curve of air humidity ratio along the channel exists all the time. To improve the regeneration efficiency, the migration time of the hump moving to the duct exit should be reduced. With the numerical analysis of the hump curve, the influences of some operating parameters on the hump value at the duct exit and its migration time are discussed.