Numerical analysis for the optimization of multi-parameters stratum ventilation and the effect on radon dispersion

Wang, Chenhua; Liu, Junjie; Yu, Chuck Wah; Xie, De

doi:10.1016/j.jobe.2022.105375

Cited by 8 publications

(3 citation statements)

References 33 publications

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“…The indoor temperature difference in the confined room was used in the Boussinesq model. 42 The discrete particle model (DPM) of the Lagrangian method was used to simulate particle dispersion in the confined room. According to a previous study, 43 due to the high evaporation rate of small droplets, the evaporation effect of small droplets considered in this study could be neglected.…”

Section: Numerical Proceduresmentioning

confidence: 99%

Mitigation of airborne transmission of COVID virus between occupants in a confined room with an air purifier

Wang

et al. 2023

Indoor and Built Environment

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This study evaluated the effect of ventilation rate and air supply angle of an air purifier using computational fluid dynamics to determine the dispersion of airborne COVID virus exhaled by an infected person. The risk of infection for an occupant was determined based on the virus concentration in the active area and accumulated particle dose within the breathing zone by varying the ventilation parameters. The air purifier was found to provide a local dilution and would block the development of an expiratory jet for a short time to reduce transmission risk. Compared to the case without an air purifier, the maximum reductions were 94.27% in the accumulated dose and 53.2% in the particle count concentration. In the breathing area, the larger air supply angle (90° > 60° > 30°) is better when the ventilation rate was 27.0 m3/h and 40.5 m3/h. Otherwise, 60° air supply angle is preferable where the ventilation rate was 54.0 m3/h. Assessing the results with the grey relational analysis revealed that the relational degree for particle count concentration was greater by varying the ventilation rate than by varying the air supply angle. However, the relational degree according to the accumulated dose was greater by varying the air supply angle than by increasing the ventilation rate. These findings may provide an important control strategy to effectively mitigate the risk of infection in a confined room by using an air purifier.

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Section: Numerical Proceduresmentioning

confidence: 99%

Mitigation of airborne transmission of COVID virus between occupants in a confined room with an air purifier

Wang

et al. 2023

Indoor and Built Environment

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“…Cheng et al [10] optimized energy efficiency and thermal comfort by reasonably controlling indoor temperature and outdoor fresh air ratio and achieved good effect. Zhang and Wang et al studied the ventilation performance of the SV system heating in winter, and the experimental results indicated that controlling supply air velocity and temperature can save energy and adapt to different thermal preferences [11,12]. Consequently, appropriate supply air parameters in the SV system can effectively improve indoor thermal environment and energy efficiency.…”

Section: Introductionmentioning

confidence: 99%

A Combinatorial Optimization Strategy for Performance Improvement of Stratum Ventilation Considering Outdoor Weather Changes and Metabolic Rate Differences: Energy Consumption and Sensitivity Analysis

Bai

Wei

2023

Sustainability

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Since occupants spend most of their time indoors, an energy-saving and comfortable indoor environment are particularly important. The differences in the metabolic rate of occupants make them have different requirements for their thermal environment. To save energy under the comprehensive needs of occupants for thermal environment, the combinatorial optimization strategy based on NSGA-II and improved the TOPSIS method is proposed in this study. Firstly, the physical model of the CFD simulation is verified by experiments. Secondly, the specific operation cases corresponding to combinations of different levels of factors are determined via the RSM method, and the ventilation performance prediction model considering the metabolic rate differences and outdoor weather changes is established. Thirdly, supply air velocities and temperatures are optimized by using Pareto-based NSGA-II; the Pareto optimal solution set under different outdoor temperatures is obtained. Finally, based on the Pareto optimal solutions at different outdoor temperatures, the optimal strategy under dynamic outdoor air temperature is obtained by improved TOPSIS by the CRITIC method. The optimization of ventilation parameters significantly improved the ventilation performance, and the results show that the predicted mean vote, energy consumption, vertical air temperature difference between head and ankle levels and the local mean age of air for different metabolic rates decrease by 64.1%, 4.74%, 24.83% and 7.39% on average, respectively. Moreover, the relative energy saving rate increases as the metabolic rate increases, and the strategy facilitates adaptation to outdoor weather changes and meets the individual needs of occupants for the indoor environment. This has important implications for achieving the global goal of energy efficiency and emission reduction.

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“…As a result, there is a global focus on studying the capture of radon from the atmosphere [4][5][6]. To date, there are three primary strategies for removing radon from confined spaces: ventilation systems [7], plugging diffusion paths [8], and adsorption methods [9,10]. Among them, the use of porous materials as solid adsorbents in adsorption methods is the most cost-effective and technically feasible approach.…”

Section: Introductionmentioning

confidence: 99%

High-Throughput Computational Screening of Two-Dimensional Covalent Organic Frameworks (2D COFs) for Capturing Radon in Moist Air

et al. 2023

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Radon (Rn) and its decay products are the primary sources of natural ionizing radiation exposure for the public, posing significant health risks, including being a leading cause of lung cancer. Porous material-based adsorbents offer a feasible and efficient solution for controlling Rn concentrations in various scenes to achieve safe levels. However, due to competitive adsorption between Rn and water, finding candidates with a higher affinity and capacity for capturing Rn in humid air remains a significant challenge. Here, we conducted high-throughput computational screening of 8641 two-dimensional covalent organic frameworks (2D COFs) in moist air using grand canonical Monte Carlo simulations. We identified the top five candidates and revealed the structure–performance relationship. Our findings suggest that a well-defined cavity with an approximate spherical inner space, with a diameter matching that of Rn, is the structural basis for a proper Rn capturing site. This is because the excellent steric match between the cavity and Rn maximizes their van der Waals dispersion interactions. Additionally, the significant polarization electrostatic potential surface of the cavity can regulate the adsorption energy of water and ultimately impact Rn selectivity. Our study offers a potential route for Rn management using 2D COFs in moist air and provides a scientific basis for further experimentation.

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Numerical analysis for the optimization of multi-parameters stratum ventilation and the effect on radon dispersion

Cited by 8 publications

References 33 publications

Mitigation of airborne transmission of COVID virus between occupants in a confined room with an air purifier

Mitigation of airborne transmission of COVID virus between occupants in a confined room with an air purifier

A Combinatorial Optimization Strategy for Performance Improvement of Stratum Ventilation Considering Outdoor Weather Changes and Metabolic Rate Differences: Energy Consumption and Sensitivity Analysis

High-Throughput Computational Screening of Two-Dimensional Covalent Organic Frameworks (2D COFs) for Capturing Radon in Moist Air

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