Ren Juan, Wang Yue, Liu Qibo, Liu Yu
School of Architecture, Chang'an University, Xi'an, Shaanxi, China.
School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an, Shaanxi, China.
Build Environ. 2021 Jan 15;188:107467. doi: 10.1016/j.buildenv.2020.107467. Epub 2020 Nov 17.
Prefabricated inpatient wards have been proven to be an efficient alternative to quickly extend the caring capacity for patients. In this study, three typical ventilation strategies were studied using computational fluid dynamics in a prefabricated Coronavirus disease 2019 double-patient ward. Pollutants are the respiratory droplets and aerosols injected from two manikins. They are modelled as particles with different diameters (3 μm, 6 μm, 12 μm, 20 μm, 45 μm and 175 μm) by the Eulerian-Lagrangian model. Three ventilation strategies with an identical air change rate of 12.3 h but different layouts of inlets and outlets are implemented. The flow field, flow structures and particle trajectories have been analysed and compared among the three ventilation strategies. The fate of particles is analysed and compared quantitatively. It is found that small particles (<20 μm) can move along with the main flow streams. Most of them are removed by ventilation to the outlet(s). Large particles (>45 μm) cannot move with the flow streams over a long path. Most of them deposit on solid surfaces in different regions of the ward in each ventilation strategy. Health workers should pay close attention to these polluted areas. Targeted cleaning of the polluted areas is necessary in a prefabricated inpatient ward. To promote the removal of some large particles (e.g., 45 μm) by the outlet(s), the outlet(s) should be installed inside the landing area of large particles and close to the polluted source(s).
预制式住院病房已被证明是快速扩大患者护理能力的一种有效替代方案。在本研究中，利用计算流体动力学对预制式2019冠状病毒病双人病房中的三种典型通风策略进行了研究。污染物为两个人体模型喷出的呼吸道飞沫和气溶胶。通过欧拉-拉格朗日模型将它们模拟为具有不同直径（3μm、6μm、12μm、20μm、45μm和175μm）的颗粒。实施了三种换气次数均为12.3 h但进风口和出风口布局不同的通风策略。对三种通风策略的流场、流动结构和颗粒轨迹进行了分析和比较。对颗粒的归宿进行了定量分析和比较。研究发现，小颗粒（<20μm）可随主流流动。它们中的大多数通过通风被排到出风口。大颗粒（>45μm）不能在长路径上随气流移动。在每种通风策略中，它们中的大多数沉积在病房不同区域的固体表面上。医护人员应密切关注这些污染区域。在预制式住院病房中，有必要对污染区域进行有针对性的清洁。为促进出风口对一些大颗粒（如45μm）的排出，出风口应安装在大颗粒沉降区域内且靠近污染源处。
