The frosting is a critical phenomenon in building systems because it decreases the performance of exchangers and damages them. In this article, heat and mass transfer in a specified liquid-to-air membrane energy exchanger (LAMEE) and their effects on condensation and frost formation are simulated numerically using the 3D computational fluid dynamics (CFD) technique. The CFD model has been validated with experimental results for different design parameters, and the agreement is within ±2%. The developed CFD model provides the distribution of temperature and humidity ratio and MgCh concentration along the LAMEE. In the present study, effects of exchanger structure on producing viscosity and heat and mass transfer are studied. The selected LAMEE is a counter cross structure, therefore vortices appear in the inlet and outlet solution channel, and their influence can be seen on heat transfer in these parts. In addition, the diffusion of heat and mass transfer are studied on distributions of temperature and humidity ratio. Results show that the permeable membrane and moisture transfer make more regular temperature distribution along airflow direction in energy exchangers. This study provides an extended vision of heat and mass transfer. A 3-dimensional CFD model is developed to predict frost formation based on obtained temperature and humidity ratio. The CFD model is validated with an experimental study by calculating the frost limit. The developed model distinguishes condensed and frosted areas, and a new parameter is defined for this purpose namely as the frosted humidity ratio. Results show that frost and condensation distributions depend significantly on temperature and humidity ratio distributions. Adjusting temperature and humidity ratio to avoid air vapor to reach to saturation conditions is the better way to combat frosting.

结霜是建筑系统中的一个关键现象，因为它会降低交换器的性能并损坏它们。在本文中，使用 3D 计算流体动力学 (CFD) 技术对特定液-空气膜能量交换器 (LAMEE) 中的传热和传质及其对冷凝和霜形成的影响进行了数值模拟。CFD模型已通过不同设计参数的实验结果进行了验证，一致性在±2%以内。开发的 CFD 模型提供了沿 LAMEE 的温度和湿度比以及 MgCh 浓度的分布。在本研究中，研究了交换器结构对产生粘度和传热传质的影响。选用的LAMEE为逆十字结构，因此在进出口溶液通道中出现涡流，可以看出它们对这些部件的传热的影响。此外，还研究了温湿度分布下的传热传质扩散。结果表明，渗透膜和水分传递使得换能器内沿气流方向的温度分布更加规则。这项研究提供了传热传质的扩展视野。开发了 3 维 CFD 模型，根据获得的温度和湿度比来预测霜的形成。CFD 模型通过计算霜冻极限进行实验研究进行验证。开发的模型区分了冷凝区域和磨砂区域，并为此定义了一个新参数，即磨砂湿度比。结果表明，霜和凝露分布很大程度上取决于温度和湿度比的分布。调节温度和湿度的比例，避免空气蒸气达到饱和状态，是对抗结霜的更好方法。