Growth of frost layer on cold fins of tube-fin heat exchangers leads to an increase in the pressure drop and a decrease in the frost thermal conductivity and thereby the heat transfer rate. There is a lack of a general model in the literature for estimating the frost thermal conductivity on parallel plate channels, including almost all parameters affecting this factor. In this study, for the first time, the general explicit semi-empirical correlations consist of dimensionless parameters are developed, which apply to parallel surface channels. The dimensionless input parameters include the wall temperature, air temperature, air velocity, frost porosity, relative humidity, specific heat of moist air, latent heat of sublimation, and operating time. The comparative results indicate that the best correlation predicts data points with an coefficient of determination, average absolute relative error, and relative root mean square error equal 0.9921, 2.755%, and 3.713%, respectively. Other available published correlations present higher deviations using the same dataset. Furthermore, to provide a good insight into this study, a sensitivity analysis is carried out employing the validated model. It is shown that the effective thermal conductivity of the frost layer is not only a function of frost density but also depends on a group of dimensionless parameters. It is observed that the thermal conductivity of the frost layer increases with the increase in the Reynolds number, Fourier number, air humidity, and it decreases with the increase in the dimensionless temperature, modified Jakob number, and porosity.

管翅式换热器的冷翅片上霜层的生长导致压降的增加和霜导热率的降低，从而导致传热速率的降低。文献中缺少用于估计平行板通道上霜冻热导率的通用模型，其中几乎包括影响该因素的所有参数。在这项研究中，首次开发了由无量纲参数组成的一般显式半经验相关性，它们适用于平行表面通道。无量纲的输入参数包括壁温，空气温度，空气速度，霜孔隙率，相对湿度，湿空气比热，升华潜热和运行时间。比较结果表明，最佳相关性可预测数据点，其确定系数，平均绝对相对误差和相对均方根误差分别等于0.9921、2.755％和3.713％。使用相同的数据集，其他可用的已发布相关性显示出更高的偏差。此外，为了提供对本研究的深入了解，使用已验证的模型进行了敏感性分析。结果表明，霜层的有效导热系数不仅是霜密度的函数，还取决于一组无量纲的参数。可以看出，霜层的热导率随雷诺数，傅立叶数，空气湿度的增加而增加，随无因次温度，修正的雅各布数的增加而降低。