Research Institute of High-tech, Xi'an, 710025, China.
Haiying Group of CASIC Co., Ltd, Beijing, 10070, China.
J Environ Radioact. 2022 Nov;253-254:107007. doi: 10.1016/j.jenvrad.2022.107007. Epub 2022 Sep 8.
Ventilation to reduce radon was one of the most widely used, important, and effective means to reduce radon concentration in underground engineering. The largest energy consumption of underground buildings was the building ventilation system. Taking the radon migration process in a room as an example, this paper built a numerical model that accounted for the mechanism of radon production, exhalation, and diffusion process, by proposing a novel intermittent ventilation strategy to mitigate radon concentration in underground space. Three ventilation strategies (no ventilation, continuous ventilation, and intermittent ventilation) were compared under various wind speeds and fresh air ratios. Under the same safe duration of radon concentration, when intermittent ventilation was operated with the same wind speed, the startup time was reduced by 79.4%, 86.0%, 90.8%, 92.8%, 91.25%, with compared with continuous ventilation. The higher the fresh air ratio, the lower the radon concentration limit, and the faster the dynamic equilibrium state of radon concentration will be reached. During intermittent ventilation, reducing the fresh air ratio can greatly increase the recovery and utilization of the return air heat, thereby reducing the power of the air conditioning unit. Considering the comprehensive energy-saving benefits of the ventilation system, the appropriate intermittent ventilation plan should be made to meet radon reduction requirements in the range of low wind speed. If low wind speed was selected, there existed advantages of low ventilation noise and more comfortable, as well.
通风降氡是降低地下工程氡浓度最广泛、最重要、最有效的手段之一。地下建筑的最大能耗是建筑通风系统。本文以室内氡迁移过程为例，建立了一个考虑氡产生、呼出和扩散过程机制的数值模型，提出了一种新的间歇通风策略，以降低地下空间的氡浓度。在不同风速和新风比下，比较了三种通风策略（无通风、连续通风和间歇通风）。在相同的氡浓度安全持续时间下，当间歇通风在相同风速下运行时，与连续通风相比，启动时间分别减少了 79.4%、86.0%、90.8%、92.8%、91.25%。新风比越高，氡浓度限值越低，氡浓度达到动态平衡状态的速度越快。在间歇通风期间，降低新风比可以大大提高回风热量的回收和利用效率，从而降低空调机组的功率。考虑到通风系统的综合节能效益，应制定适当的间歇通风计划，以满足低风速下的氡减排要求。如果选择低风速，则具有通风噪声低、舒适性好等优点。
