A Method for the Assessment of the Inhalation Dose Exposure to Radionuclides in an Indoor Environment

2013 ◽  
Vol 477-478 ◽  
pp. 412-422
Author(s):  
Xiao Feng Hu ◽  
Hong Huang ◽  
Shi Fei Shen ◽  
Hong Yong Yuan
Keyword(s):  
Wind Velocity ◽  
Urban Areas ◽  
Indoor Environment ◽  
Power Plants ◽  
Natural Ventilation ◽  
Wind Pressure ◽  
Inhalation Dose ◽  
Building Height ◽  
Ventilation Coefficient ◽  
Street Width

The radionuclides released from NPPs (Nuclear Power Plants) as a result of accidents will significantly affect human health by causing cancer, genetic diseases, or acute radiation sickness. To investigate and evaluate the influence of the airborne hazardous materials on human bodies in an indoor environment in urban areas near NPPs, it is necessary to calculate the inhalation dose. In this study, a method for the assessment of the inhalation dose of indoor radionuclides was proposed. This method consists of the combination of the basic equation of natural ventilation and the empirical equation for calculation of the inhalation dose. The method was applied in a modeled densely urban domain, and CFD simulations were conducted to obtain the wind pressure distribution on the building surfaces. Moreover, the impacts of certain important parameters, including the ventilation coefficient, the age group of humans, the wind velocity, the urban street width, and the building height, were discussed in this paper. The results show that all of these parameters affect the indoor inhalation dose. In most cases, the indoor dose obtained at the same floor was higher with a higher ventilation coefficient, breathing rate, wind velocity, and street width or a lower building height. Furthermore, people living in the middle floors will generally be exposed to a lower inhalation dose than those in other floors especially the top floor.

The Study of Building Indoor and Outdoor Wind Environment

2012 ◽  
Vol 482-484 ◽  
pp. 2592-2595 ◽  
Author(s):  
Zhong Hua Tang ◽  
Ri Chao Liu ◽  
De Bao Lei
Keyword(s):  
Numerical Simulation ◽  
Wind Field ◽  
Indoor Environment ◽  
Natural Ventilation ◽  
High Quality ◽  
Wind Environment ◽  
Building Height ◽  
Building Layout ◽  
Indoor And Outdoor

Through FLUENT numerical simulation, this paper is aimed on studying the influence of outdoor wind environment on indoor environment. We found that building height, building layout format and opening format in the wall are significant impacted on indoor natural ventilation. At the three-fourth height of building, if the building layout and housing opening is stagger, it can get high-quality indoor natural ventilation and more evenly indoor wind field.

Thermo-Aeraulic Simulation of Mono Façade Natural Ventilation

2017 ◽  
Vol 21 ◽  
pp. 514-519
Author(s):  
Mircea Horne Horneț ◽  
Raluca Dania Todor ◽  
Nicolae Fani Iordan ◽  
Mircea Drăghici ◽  
Cristian Năstac ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Indoor Environment ◽  
Natural Ventilation ◽  
Energy Use ◽  
Thermal Response ◽  
Wind Pressure ◽  
Physical Processes ◽  
Efficient Alternative ◽  
Ventilation Rates ◽  
Indoor And Outdoor

Natural ventilation is an energy efficient alternative for reducing the energy use in buildings, achieving thermal comfort and maintaining a healthy indoor environment. Differences in wind pressure along the façade and differences between indoor and outdoor temperatures create a natural air exchange between indoor and outdoor air. These physical processes are complex, and predicting ventilation rates is difficult. This paper presents a method for determining natural ventilation air flow in single-façade thermo-air system by simulating the room using the program TRNSYS 16. Theoretical checking of the airflow obtained by simulation was performed by comparing the thermal response in the room following the simulation, with interior temperatures measured during the experiment.

URBAN FACADE GEOMETRY ON OUTDOOR COMFORT CONDITIONS: A REVIEW

2020 ◽  
Vol 4 (1) ◽  
pp. 45
Author(s):  
Elahe Mirabi ◽  
Nasrollahi Nazanin
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Natural Ventilation ◽  
Flow Behavior ◽  
Air Flow ◽  
Urban Geometry ◽  
Wide Range ◽  
Low Energy Buildings ◽  
Outdoor Comfort ◽  
Solar Access

<p>Designing urban facades is considered as a major factor influencing issues<br />such as natural ventilation of buildings and urban areas, radiations in the<br />urban canyon for designing low-energy buildings, cooling demand for<br />buildings in urban area, and thermal comfort in urban streets. However, so<br />far, most studies on urban topics have been focused on flat facades<br />without details of urban layouts. Hence, the effect of urban facades with<br />details such as the balcony and corbelling on thermal comfort conditions<br />and air flow behavior are discussed in this literature review. <strong>Aim</strong>: This<br />study was carried out to investigate the effective factors of urban facades,<br />including the effects of building configuration, geometry and urban<br />canyon’s orientation. <strong>Methodology and Results</strong>: According to the results,<br />the air flow behavior is affected by a wide range of factors such as wind<br />conditions, urban geometry and wind direction. Urban façade geometry<br />can change outdoor air flow pattern, thermal comfort and solar access.<br /><strong>Conclusion, significance and impact study</strong>: In particular, the geometry of<br />the facade, such as indentation and protrusion, has a significant effect on<br />the air flow and thermal behavior in urban facades and can enhance<br />outdoor comfort conditions. Also, Alternation in façade geometry can<br />affect pedestrians' comfort and buildings energy demands.</p>

scholarly journals Indoor Climate Performance in a Renovated School Building

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2827
Author(s):  
Pavla Mocová ◽  
Jitka Mohelníková
Keyword(s):  
Indoor Environment ◽  
Natural Ventilation ◽  
Carbon Dioxide Concentration ◽  
Heating System ◽  
Climatic Conditions ◽  
School Building ◽  
Ventilation Strategy ◽  
Indoor Climate ◽  
Microbiological Testing ◽  
Indoor Comfort

Indoor climate comfort is important for school buildings. Nowadays, this is a topical problem, especially in renovated buildings. Poorly ventilated school classrooms create improper conditions for classrooms. A post-occupancy study was performed in a school building in temperate climatic conditions. The evaluation was based on the results of long-term monitoring of the natural ventilation strategy and measurements of the carbon dioxide concentration in the school classroom’s indoor environment. The monitoring was carried out in an old school building that was constructed in the 1970s and compared to testing carried out in the same school classroom after the building was renovated in 2016. Surprisingly, the renovated classroom had a significantly higher concentration of CO2. It was found that this was due to the regulation of the heating system and the new airtight windows. The occupants of the renovated classroom have a maintained thermal comfort, but natural ventilation is rather neglected. A controlled ventilation strategy and installation of heat recovery units are recommended to solve these problems with the classroom’s indoor environment. Microbiological testing of the surfaces in school classrooms also shows the importance of fresh air and solar radiation access for indoor comfort.

scholarly journals Key Performance Indicators for an Energy Community Based on Sustainable Technologies

2021 ◽  
Vol 13 (16) ◽  
pp. 8789
Author(s):  
Giovanni Bianco ◽  
Barbara Bonvini ◽  
Stefano Bracco ◽  
Federico Delfino ◽  
Paola Laiolo ◽  
...  
Keyword(s):  
Performance Indicators ◽  
Urban Areas ◽  
High Performance ◽  
Power Plants ◽  
New Technologies ◽  
Storage Systems ◽  
Clean Energy ◽  
Key Performance Indicators ◽  
Energy Performance ◽  
Green Energy

As reported in the “Clean energy for all Europeans package” set by the EU, a sustainable transition from fossil fuels towards cleaner energy is necessary to improve the quality of life of citizens and the livability in cities. The exploitation of renewable sources, the improvement of energy performance in buildings and the need for cutting-edge national energy and climate plans represent important and urgent topics to be faced in order to implement the sustainability concept in urban areas. In addition, the spread of polygeneration microgrids and the recent development of energy communities enable a massive installation of renewable power plants, high-performance small-size cogeneration units, and electrical storage systems; moreover, properly designed local energy production systems make it possible to optimize the exploitation of green energy sources and reduce both energy supply costs and emissions. In the present paper, a set of key performance indicators is introduced in order to evaluate and compare different energy communities both from a technical and environmental point of view. The proposed methodology was used in order to assess and compare two sites characterized by the presence of sustainable energy infrastructures: the Savona Campus of the University of Genoa in Italy, where a polygeneration microgrid has been in operation since 2014 and new technologies will be installed in the near future, and the SPEED2030 District, an urban area near the Campus where renewable energy power plants (solar and wind), cogeneration units fed by hydrogen and storage systems are planned to be installed.

Effects of different wind directions on ventilation of surrounding areas of two generic building configurations in Hong Kong

2021 ◽  
pp. 1420326X2110160
Author(s):  
Kai Yip Lee ◽  
Cheuk Ming Mak
Keyword(s):  
Wind Velocity ◽  
Natural Ventilation ◽  
Urban Environments ◽  
Air Pressure ◽  
Pressure Distributions ◽  
Air Intake ◽  
Dynamics Simulations ◽  
Surrounding Areas ◽  
Effective Use ◽  
Velocity Zone

This study investigated effects of incident wind angles on wind velocity distributions in wakes of two generic building configurations, namely, ‘T’- and ‘+’-shaped, and the air pressure distributions along their leeward walls by using computational fluid dynamics simulations. Results show that when the wind approaches laterally (90°) (vs. when the wind is direct (0°)), the downwind length and maximum bilateral width of the low-wind velocity zone in the wake of ‘T’-shaped building decrease by 11.5% and 37.9%, respectively. When the incident wind is oblique (45°) (vs. when it is direct), the length and width of this low-wind velocity zone in the wake of ‘+’-shaped building decrease by 15.0% and 30.9%, respectively. Furthermore, results show that the air pressure on the leeward walls of the ‘T’- and ‘+’-shaped buildings gradually decreases along with the building height. The resulting low-wind conditions on upper floors of buildings reduce the fresh air intake of their leeward units utilizing natural ventilation. It is particularly apparent in the case of direct approaching wind. Thus, the appropriate selection of building configurations and their orientations allows for the most effective use of wind to enhance ventilation in indoor and urban environments.

CFD Modeling of Pressure Coefficients for a Natural Ventilation Study in an Experimental Low Rise Building

2013 ◽  
Author(s):  
Robel Kiflemariam ◽  
Cheng-Xian Lin
Keyword(s):  
Natural Ventilation ◽  
Pressure Coefficient ◽  
Wind Pressure ◽  
Analytical Models ◽  
Cfd Modeling ◽  
Engineering Practice ◽  
Pressure Coefficients ◽  
Wind Pressure Coefficient ◽  
Detailed Assessment ◽  
Ventilation Rates

Mean wind pressure coefficient (Cp) is one of the major input data for natural ventilation study using building energy simulation approach. Due to their importance, they need to be accurately determined. In current engineering practice, tables and analytical Cp models only give mostly averaged results for simpler models and configurations. Considering the limitation of tables and analytical models, Computational Fluid Dynamics (CFD) could provide a means for an accurate and detailed assessment of Cp. In this paper, we make use of a relatively high resolution, detailed experiments done at Florida Intentional University to validate a CFD modeling of the pressure coefficients Cp. The results show that existing CFD model has a good agreement with experimental results and gives important information of distribution of Cp values over the surface. The local values of the Cp are investigated. In addition, the CFD derived Cp and discharge coefficient (Cd) values are utilized in semi-analytical ventilation models in order to get a more accurate value of ventilation rates.

scholarly journals Leveraging machine learning to produce a cost-effective national building height map of Ireland

2021 ◽  
Author(s):  
Eoghan Keany ◽  
Geoffrey Bessardon ◽  
Emily Gleeson
Keyword(s):  
Machine Learning ◽  
Remote Sensing ◽  
High Resolution ◽  
Land Cover ◽  
Urban Areas ◽  
Cost Effective ◽  
Land Cover Classification ◽  
National Scale ◽  
Building Height ◽  
Height Data

&lt;p&gt;To represent surface thermal, turbulent and humidity exchanges, Numerical Weather Prediction (NWP) systems require a land-cover classification map to calculate sur-face parameters used in surface flux estimation. The latest land-cover classification map used in the HARMONIE-AROME configuration of the shared ALADIN-HIRLAMNWP system for operational weather forecasting is ECOCLIMAP-SG (ECO-SG). The first evaluation of ECO-SG over Ireland suggested that sparse urban areas are underestimated and instead appear as vegetation areas (1). While the work of (2) on land-cover classification helps to correct the horizontal extent of urban areas, the method does not provide information on the vertical characteristics of urban areas. ECO-SG urban classification implicitly includes building heights (3), and any improvement to ECO-SG urban area extent requires a complementary building height dataset.&lt;/p&gt;&lt;p&gt;Openly accessible building height data at a national scale does not exist for the island of Ireland. This work seeks to address this gap in availability by extrapolating the preexisting localised building height data across the entire island. The study utilises information from both the temporal and spatial dimensions by creating band-wise temporal aggregation statistics from morphological operations, for both the Sentinel-1A/B and Sentinel-2A/B constellations (4). The extrapolation uses building height information from the Copernicus Urban Atlas, which contains regional coverage for Dublin at 10 m x10 m resolution (5). Various regression models were then trained on these aggregated statistics to make pixel-wise building height estimates. These model estimates were then evaluated with an adjusted RMSE metric, with the most accurate model chosen to map the entire country. This method relies solely on freely available satellite imagery and open-source software, providing a cost-effective mapping service at a national scale that can be updated more frequently, unlike expensive once-off private mapping services. Furthermore, this process could be applied by these services to reduce costs by taking a small representative sample and extrapolating the rest of the area. This method can be applied beyond national borders providing a uniform map that does not depends on the different private service practices facilitating the updates of global or continental land-cover information used in NWP.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;(1) G. Bessardon and E. Gleeson, &amp;#8220;Using the best available physiography to improve weather forecasts for Ireland,&amp;#8221; in Challenges in High-Resolution Short Range NWP at European level including forecaster-developer cooperation, European Meteorological Society, 2019.&lt;/p&gt;&lt;p&gt;(2) E. Walsh, et al., &amp;#8220;Using machine learning to produce a very high-resolution land-cover map for Ireland, &amp;#8221; Advances in Science and Research,&amp;#160; (accepted for publication).&lt;/p&gt;&lt;p&gt;(3) CNRM, &quot;Wiki - ECOCLIMAP-SG&quot; https://opensource.umr-cnrm.fr/projects/ecoclimap-sg/wiki&lt;/p&gt;&lt;p&gt;(4) D. Frantz, et al., &amp;#8220;National-scale mapping of building height using sentinel-1 and sentinel-2 time series,&amp;#8221; Remote Sensing of Environment, vol. 252, 2021.&lt;/p&gt;&lt;p&gt;(5) M. Fitrzyk, et al., &amp;#8220;Esa Copernicus sentinel-1 exploitation activities,&amp;#8221; in IGARSS 2019-2019 IEEE International Geoscience and Remote Sensing Symposium, IEEE, 2019.&lt;/p&gt;

Determination of Basic Wind Velocity for Wind Load-Governed Limit State

2019 ◽  
Author(s):  
Ji Hyeon Kim ◽  
Hae-Sung Lee
Keyword(s):  
Wind Velocity ◽  
Reliability Index ◽  
General Procedure ◽  
Limit State ◽  
Wind Load ◽  
Wind Pressure ◽  
Load Factor ◽  
Load Effect ◽  
Design Life ◽  
Target Reliability Index

<p>This paper proposes a general procedure for evaluating a nominal value of wind velocity for a wind load- governed limit state to secure a target reliability index during the design life of a structure. The nominal value of wind velocity, referred to as a basic wind velocity, and wind load factor should be determined so that the factored wind load effect secures a target reliability index for a wind load-governed limit state. In this study, the analytical form of the return period of the basic wind velocity is expressed as a function of the target reliability index, wind load factor, and statistical parameters of wind pressure, which are derived as linear functions of the coefficient of wind velocity. The proposed approach is applied to the Korean Highway Bridge Design Code-Cable supported Bridge, which specifies the design life of a structure as 100- and 200-year.</p>

Sign in / Sign up

Export Citation Format

Share Document