Abstract Characterizing the emission performance of formaldehyde is critical for control strategies. Most previous emission models assume that formaldehyde concentrations are well-mixed. In this study, a computational fluid dynamics-based model is developed for simulating the mass transfer and adsorption/desorption processes of formaldehyde from particleboards in a chamber with a mixing fan. Numerical investigations on the impacts of the mixing fan, adsorption/desorption rate constants, and key transport parameters influencing the emission behaviors are conducted for the first time. The results show that the complete mixing assumption is not appropriate in the early emission period. Incomplete mixing becomes more significant with a decreasing rotation speed, leading to a time-dependent equivalent mass transfer coefficient. The deviation in the maximum concentration between the simulated curves with and without the adsorption/desorption effect is approximately 8.5%. A coefficient of mixing of 0.0283 is suitable for evaluating complete mixing in the chamber. With an increase in the rotation speed, the degree of mixing improves, and the mass transfer coefficient increases sub-linearly. Secondary reemission becomes more significant and begins earlier for materials with lower partition coefficients and higher diffusivity.

中文翻译：

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带有混合风扇和通风口的小型试验室中甲醛释放和吸附过程的计算流体动力学预测

摘要 表征甲醛的排放性能对于控制策略至关重要。大多数以前的排放模型都假设甲醛浓度是混合良好的。在这项研究中，开发了一种基于计算流体动力学的模型，用于模拟带有混合风扇的室内刨花板中甲醛的传质和吸附/解吸过程。首次对混合风扇、吸附/解吸速率常数和影响排放行为的关键传输参数的影响进行了数值研究。结果表明，完全混合假设在早期排放期是不合适的。随着转速的降低，不完全混合变得更加明显，导致与时间相关的等效传质系数。有和没有吸附/解吸效应的模拟曲线之间的最大浓度偏差约为 8.5%。0.0283 的混合系数适用于评估腔室中的完全混合。随着转速的增加，混合程度提高，传质系数呈亚线性增加。对于分配系数较低和扩散率较高的材料，二次再发射变得更加重要并且开始得更早。