scholarly journals Sensitivity Analysis of Envelope Design Parameters of Industrial Buildings with Natural Ventilation

2020 ◽  
Vol 12 (24) ◽  
pp. 10288
Author(s):  
Xiaojing Meng ◽  
Beibei Wei ◽  
Yingni Zhai
Keyword(s):  
Sensitivity Analysis ◽  
Natural Ventilation ◽  
Internal Heat ◽  
Cold Climate ◽  
Design Parameters ◽  
Industrial Buildings ◽  
The Impact ◽  
The City ◽  
Important Design ◽  
The Heat Transfer Coefficient

It is beneficial for designers to identify the most important design parameters of building envelopes. This study undertook sensitivity analysis integrated with EnergyPlus to assess the impacts of envelope design parameters for naturally ventilated industrial buildings. Sensitivity coefficients of six envelope design parameters for different internal heat intensities were analyzed and compared for buildings in the city of Xi’an, located in the cold climate zone of China. Our results showed that the heat transfer coefficient of the roofs had the most significant impact on indoor temperature. The weights were 32.29%, 33.71% and 30.71%, and the heat intensities were 5, 10 and 15 W/m3, respectively. The effect of the skylight-to-roof ratio was the second most sensitive. The impact of the solar absorptances of the walls and roof on the total number of hours was not sensitive. The results could be helpful for designers to efficiently form alternative design solutions in the design of new and retrofitting industrial buildings.

Nanoparticle aggregation kinematics on the quadratic convective magnetohydrodynamic flow of nanomaterial past an inclined flat plate with sensitivity analysis

2021 ◽  
pp. 095440892110562
Author(s):  
AS Sabu ◽  
Joby Mackolil ◽  
B Mahanthesh ◽  
Alphonsa Mathew
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Sensitivity Analysis ◽  
Heat Transfer Coefficient ◽  
Heat Source ◽  
Transfer Coefficient ◽  
Flat Plate ◽  
Inclined Plate ◽  
The Impact ◽  
The Heat Transfer Coefficient

The study focuses on the aggregation kinematics in the quadratic convective magneto-hydrodynamics of ethylene glycol-titania ([Formula: see text]) nanofluid flowing through an inclined flat plate. The modified Krieger-Dougherty and Maxwell-Bruggeman models are used for the effective viscosity and thermal conductivity to account for the aggregation aspect. The effects of an exponential space-dependent heat source and thermal radiation are incorporated. The impact of pertinent parameters on the heat transfer coefficient is explored by using the Response Surface Methodology and Sensitivity Analysis. The effects of several parameters on the skin friction and heat transfer coefficient at the plate are displayed via surface graphs. The velocity and thermal profiles are compared for two physical scenarios: flow over a vertical plate and flow over an inclined plate. The nonlinear problem is solved using the Runge–Kutta-based shooting technique. It was found that the velocity profile significantly decreased as the inclination of the plate increased on the other hand the temperature profile improved. The heat transfer coefficient decreased due to the increase in the Hartmann number. The exponential heat source has a decreasing effect on the heat flux and the angle of inclination is more sensitive to the heat transfer coefficient than other variables. Further, when radiation is incremented, the sensitivity of the heat flux toward the inclination angle augments at the rate 0.5094% and the sensitivity toward the exponential heat source augments at the rate 0.0925%. In addition, 41.1388% decrement in wall shear stress is observed when the plate inclination is incremented from [Formula: see text] to [Formula: see text].

Natural-hydraulic fracture interaction: Microseismic observations and geomechanical predictions

2015 ◽  
Vol 3 (3) ◽  
pp. SU17-SU31 ◽  
Author(s):  
Jian Huang ◽  
Reza Safari ◽  
Uno Mutlu ◽  
Kevin Burns ◽  
Ingo Geldmacher ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Hydraulic Fracture ◽  
Fracture Network ◽  
Natural Fracture ◽  
Design Parameters ◽  
Reservoir Area ◽  
Complex Fracture ◽  
Model Complex ◽  
Fracture Interaction ◽  
The Impact

Natural fractures can reactivate during hydraulic stimulation and interact with hydraulic fractures producing a complex and highly productive natural-hydraulic fracture network. This phenomenon and the quality of the resulting conductive reservoir area are primarily functions of the natural fracture network characteristics (e.g., spacing, height, length, number of fracture sets, orientation, and frictional properties); in situ stress state (e.g., stress anisotropy and magnitude); stimulation design parameters (e.g., pumping schedule, the type/volume of fluid[s], and proppant); well architecture (number and spacing of stages, perforation length, well orientation); and the physics of the natural-hydraulic fracture interaction (e.g., crossover, arrest, reactivation). Geomechanical models can quantify the impact of key parameters that control the extent and complexity of the conductive reservoir area, with implications to stimulation design and well optimization in the field. We have developed a series of geomechanical simulations to predict natural-hydraulic fracture interaction and the resulting fracture network in complex settings. A geomechanics-based sensitivity analysis was performed that integrated key reservoir-geomechanical parameters to forward model complex fracture network generation, synthetic microseismic (MS) response, and associated conductivity paths as they evolve during stimulation operations. The simulations tested two different natural-hydraulic fracture interaction scenarios and could generate synthetic MS events. The sensitivity analysis revealed that geomechanical models that involve complex fracture networks can be calibrated against MS data and can help to predict the reservoir response to stimulation and optimize the conductive reservoir area. We analyzed a field data set (obtained from two hydraulically fractured wells in the Barnett Formation, Tarrant County, Texas) and established a coupling between the geomechanics and MS within the framework of a 3D geologic model. This coupling provides a mechanics-based approach to (1) verify MS trends and anomalies in the field, (2) optimize conductive reservoir area for reservoir simulations, and (3) improve stimulation design on the current well in near-real-time and well design/stimulation for future wells.

scholarly journals Sensitivity Analysis of Passive Design Strategies for Residential Buildings in Cold Semi-Arid Climates

2020 ◽  
Vol 12 (3) ◽  
pp. 1091 ◽  
Author(s):  
Waqas Ahmed Mahar ◽  
Griet Verbeeck ◽  
Sigrid Reiter ◽  
Shady Attia
Keyword(s):  
Sensitivity Analysis ◽  
Thermal Comfort ◽  
Residential Buildings ◽  
Design Parameters ◽  
Rapid Urbanization ◽  
Design Recommendations ◽  
Adaptive Comfort ◽  
Passive Design ◽  
The Impact ◽  
Semi Arid

Buildings are significant drivers of greenhouse gas emissions and energy consumption. Improving the thermal comfort of occupants in free-running buildings and avoiding active and fossil fuel-based systems is the main challenge in many cities worldwide. However, the impacts of passive design measures on thermal comfort in cold semi-arid regions are seldom studied. With the rapid urbanization and the widespread use of personalised heating and cooling systems, there is a need to inform building designers and city authorities about passive design measures that can achieve nearly optimal conditions. Therefore, in this study, a global sensitivity analysis of the impact of passive design parameters on adaptive comfort in cold semi-arid climates was conducted. A representative residential building was simulated and calibrated in Quetta, Pakistan, to identify key design parameters for optimal thermal comfort. The results list and rank a set of passive design recommendations that can be used widely in similar climates. The results show that among the investigated 21 design variables, the insulation type of roof is the most influential design variable. Overall, the sensitivity analysis yielded new quantitative and qualitative knowledge about the passive design of buildings with personalised heating systems, but the used sensitivity analysis has some limitations. Finally, this study provides evidence-based and informed design recommendations that can serve architects and homeowners to integrate passive design measures at the earliest conceptual design phases in cold semi-arid climates.

Reducing the Risk of Natural Ventilation With Flexible Design

Solar Energy ◽  
2006 ◽  
Author(s):  
Lara V. Greden ◽  
Leon R. Glicksman ◽  
Gabriel Lo´pez-Betanzos
Keyword(s):  
Natural Ventilation ◽  
Energy Savings ◽  
Cooling System ◽  
Building Energy ◽  
Design Parameters ◽  
Energy Prices ◽  
Flexible Design ◽  
Local Climate ◽  
Capital Costs ◽  
The Impact

Performance uncertainty is a barrier to implementation of innovative technologies. This research investigates the potential of flexible design — one that enables future change — to improve the economic performance of a naturally ventilated building. The flexible design of the naturally ventilated building enables future installation of a mechanical cooling system by including features such as space for pipes and chillers. The benefits of the flexible design are energy savings, delay of capital costs and capability of mitigating the risk of a failed building (by installing the mechanical cooling system). To evaluate the flexible design, building energy simulation is conducted over a multi-year time period with stochastic outdoor temperature variables. One result is a probability distribution of the time when the maximum allowable indoor temperature under natural ventilation is exceeded, which may be “never.” Probability distributions are also obtained for energy savings and cost savings as compared to a mechanically cooled building. Together, these results allow decision-makers to evaluate the long-term performance risks and opportunities afforded by a flexible implementation strategy for natural ventilation. It is shown that the likelihood of future installation of mechanical cooling is most sensitive to design parameters. The impact of increased climate variability depends on the local climate. The probability of installing the mechanical system also depends on the comfort criteria. The results show that capital costs for cooling equipment are much greater than the present value of 10 years of cooling energy costs. This result motivates consideration of flexible design as opposed to hybrid cooling designs (which have immediate installation of mechanical cooling). Future work will study the impact of uncertain energy prices on investment attractiveness of naturally ventilated buildings. Other applications of the framework presented herein include replacing the building energy model with a model of another climate-dependent system, such as solar photovoltaic arrays.

The Automobile Tension Bar Time-Varying Reliability Sensitivity Analysis

2014 ◽  
Vol 620 ◽  
pp. 143-147
Author(s):  
Shu Sen Liu ◽  
Bo Qiang Shi ◽  
Wen Yu Zhang ◽  
Xue Jie Fu ◽  
Yue Wei Wu
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Optimization Design ◽  
Design Parameters ◽  
Time Varying ◽  
Reliability Sensitivity ◽  
Reliability Sensitivity Analysis ◽  
Robust Optimal Design ◽  
Robust Optimization Design ◽  
The Impact

In this paper, the design of a automobile tension bar analysis example, the use of sensitivity analysis of time-varying reliability robust optimal design tension bar design parameters for reliability sensitivity analysis shows that the reliability of the impact of the strength of the material and rod diameter is positive, and the reliability of the impact of the load and rod diameter is negative. Correct application of time-varying reliability robust optimal design of mechanical parts when variant reliability robust optimization design, design service at any time during the period were not sensitive to changes of the design parameters of the reliability of the parts, and improve the parts reliability soundness.

scholarly journals Influence of glazing type on energy efficiency of industrial buildings in the process of revitalization: A case study

2019 ◽  
Vol 17 (1) ◽  
pp. 33-44
Author(s):  
Branko Slavkovic
Keyword(s):  
Comparative Analysis ◽  
Carbon Dioxide Emissions ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Industrial Building ◽  
Industrial Buildings ◽  
Double Skin ◽  
The Impact ◽  
The City

This paper examines the possibilities of improving the energy performance of an existing industrial building by application of the double skin fa?ade on the revitalization of the building envelope in the climatic conditions of the city Novi Pazar, Republic of Serbia. The aim is to examine the impact of choosing the type of glazing, in the processes of revitalization, on the energy needs of industrial buildings for heating and cooling, as well as the contribution of the measures implemented to improve the energy performance of the selected type and model of industrial building. The energy performance of buildings was obtained using the software DesignBuilder and EnergyPlus simulation platform, taking into account the parameters of required internal temperature and climate data for the Republic of Serbia. The comparative analysis of the results of energy simulation according to the criterion of achieving greater energy savings and reduced carbon dioxide emissions was performed. The methodological approach in this research involves creating revitalization scenarios of industrial buildings with a shed roof construction, selection of the specific building according to whose properties by numerical simulation possibilities for energy revitalization depletion were investigated and comparative analysis of the obtained results was performed. The primary objective of this research is to investigate the impact of choosing the type of glazing on the energy performance of industrial buildings with a shed roof construction and to determine the optimal approach to energy revitalization of existing industrial buildings with the implementation of the double skin fa?ade under the climatic conditions of the city Novi Pazar, Republic of Serbia. The results of this paper indicate the negative characteristics of the kopilit glass to solar gains, whose retention requires a large amount of heating energy. While replacing of kopilit glass with a low-energy glass increases the amount of energy required to cooling of the building. With this research, through various revitalization scenarios, it is also indicated that using a double skin fa?ade in the revitalization process of the selected building, has a very similar impact on reducing CO2 emissions regardless of the type of glazing choice.

scholarly journals Anthropogenic Photolabile Chlorine in the Cold-Climate City of Montreal

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 812
Author(s):  
Ryan Hall ◽  
Oleg Nepotchatykh ◽  
Evguenia Nepotchatykh ◽  
Parisa A. Ariya
Keyword(s):  
Chloride Ion ◽  
Particle Morphology ◽  
Chloride Ions ◽  
Cold Climate ◽  
Anthropogenic Sources ◽  
Oxidative Potential ◽  
Chlorine Atoms ◽  
The Impact ◽  
The City ◽  
Cl Atoms

Chlorine atoms play a key role in the oxidative potential of the atmosphere and biogeochemical cycling of selected elements. This study provides a decadal analysis (2010−2019) of chloride ions in PM2.5 particles in the city of Montreal, where these are most concentrated systematically in the winter (up to 1.6 µg/m3). We also herein present the measurement of photolabile chlorine, which includes chlorine-containing compounds (e.g., Cl2, HOCl, ClNO2, ClNO3, and BrCl) that release chlorine atoms upon interaction with radiation, in urban Montreal, Canada using Cl2-RPGE (Cl2 Reactive Phase Gas Extraction) tubes and quantifying the chlorinated product by GC-MS. Photolabile chlorine in urban Montreal was measured during a discontinuous period primarily in summer 2018 and winter 2019 with a time resolution of 30 min, with concentrations ranging from 3 to 545 ng/m3 expressed as Cl2. The reported values are considered lower limits, as compounds such as HOCl and ClNO2 can only be partially converted in the current setup. The largest peak of gaseous photolabile chlorine occurred in the winter, when significant sources of anthropogenic salt are used in snow removal in the city. This coincides with observed chloride ion measurements in airborne particles, implying that anthropogenic salt addition produces photoactive chlorine. The maximum chlorine signal was consistently obtained during the daytime, which is in accordance with the tropospheric radiation profile. Complementary photochemistry laboratory experiments indicated that upon tropospheric radiation (340 ≤ λ ≤ 400 nm; UVA), an increase (20–100%) was observed, confirming the formation of Cl atoms from photolabile chlorine compounds. Thus, this portable technique is adequate for Cl atoms and photolabile chlorine-containing compounds upon photolysis using UVA lamps. High-resolution S/TEM and energy-dispersive X-ray spectroscopy (EDS) were used to evaluate collected particle morphology and composition. The behavior of complementary pollutants (O3, CO, PM2.5, and NOx) was also briefly discussed. We herein discuss the measurement of photolabile halogens within a northern urban metropolitan environment and the impact of anthropogenic sources on chlorine concentrations.

Parameter Sensitivity and Reliability Analysis for Construction Control of Cable-Net Structure Supporting the Reflector of FAST

2013 ◽  
Vol 671-674 ◽  
pp. 529-533
Author(s):  
Xu Kong ◽  
Qi Ming Wang ◽  
Chuan Jia Liu ◽  
Zhong Yi Zhu
Keyword(s):  
Sensitivity Analysis ◽  
Global Sensitivity Analysis ◽  
Structural Parameters ◽  
Element Model ◽  
Parameter Sensitivity ◽  
Tension Force ◽  
Design Parameters ◽  
Structural Parameter ◽  
Global Sensitivity ◽  
The Impact

Five-hundred-meter Aperture Spherical radio Telescope (FAST) is supported by cable-net structure, which enables its surface to form a paraboloid in real time under active control. FAST is now entering project construction and implement stage, however there are always a considerable amount of errors existed in practice which would result in the deviation of the structure from its ideal model. Therefore, structural parameter sensitivity analysis was indispensable discussed. In the paper, the variation ranges of structural parameters were rationally determined. Base on local sensitivity analysis and global sensitivity analysis method, Using the finite element model investigated the influence of different structural parameters change on the static behavior, gets the conclusions that the impact of several key design parameters on the tension force of cable-net is large. The results indicate that of all types of the structural parameters, the error of the length of cable plays the most important role, and the global sensitivity analysis indicates that the tension force range of cable-net is -18% to 27%.

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