scholarly journals Heat flow redistribution in wall structure during diurnal cycle in summer

2021 ◽  
Vol 23 (2) ◽  
pp. 96-104
Author(s):  
A. N. Belous ◽  
O. E. Belous ◽  
S. V. Krakhin
Keyword(s):  
Heat Flow ◽  
Flow Distribution ◽  
Climatic Conditions ◽  
Wall Structure ◽  
Main Role ◽  
Summer Period ◽  
Transfer Resistance ◽  
Wall Structures ◽  
Calculation Results ◽  
Main Factor

The standardized indicator is the heat transfer resistance as the main factor that plays the main role in assessing the energy efficiency of the thermal envelope of a building. During the last decades, the climatic conditions change toward the increase in average daily temperature in the summer period. Thus, the thermal resistance of external wall structures becomes more and more urgent. This problem is reduced to an assumption that the heat flow in the wall structure is directed from the external surface to the internal. This paper analyzes the heat flow distribution and redistribution in time in the wall structure. The paper presents a comparative analysis of the modelling and calculation results of the nonstationary heat flow for solving the thermal stability problem.

Engineering Method for Calculating the Temperature on the Inner Surface of the Outer Corner of a Building

2021 ◽  
pp. 25-36
Author(s):  
Н. П. Умнякова
Keyword(s):  
Outer Wall ◽  
Engineering Calculation ◽  
Engineering Method ◽  
Wall Structure ◽  
Outer Corner ◽  
Wall Structures ◽  
Inner Surface ◽  
Calculation Results ◽  
Floor Surfaces ◽  
The Heat Balance

Постановка задачи. Температура на внутренней поверхности наружного угла всегда меньше, чем по глади наружной стены, что при низких температурах наружного воздуха может приводить к образованию конденсата на внутренней поверхности стены. В связи с этим актуальным является проблема разработки инженерного метода расчета температуры в наружном углу для исключения возможности конденсатообразования на внутренней поверхности угла на стадии проектирования стеновых конструкций. Результаты. Для решения этой задачи на основе решения уравнения теплового баланса, учета амплитуды колебания температуры воздуха в помещении и теплопоглощения внутренних поверхностей стен, междуэтажных перекрытий (поверхности потолка и пола), перегородок, окон получена формула для вычисления температуры на внутренней поверхности наружного угла. Также в ходе исследования проведены натурные испытания стеновой конструкции с наружным углом и получены значения температур на внутренней и наружной поверхностях. Выводы. Сопоставление результатов расчетов по разработанной методике и экспериментальных данных показало, что значения температур на внутренней поверхности наружного угла практически совпадают. Это дает основание использовать предложенный инженерный метод расчета температуры на внутренней поверхности угла наружной стены при проектировании ограждающих конструкций зданий для создания благоприятных комфортных и санитарно-гигиенических условий в помещении. Statement of the problem. The temperature on the inner surface of the outer corner is always lower than on the inner surface of the outer wall. This temperature difference might lead to the formation of condensation on the inner surface of the wall at low outdoor temperatures. Therefore the problem of developing an engineering method for calculating the temperature in the outer corner to exclude the possibility of condensation on the inner surface in the design process of the outer wall structures is extremely relevant. Results. To address this problem, based on solving the heat balance equation, taking into account the amplitude of air temperature fluctuations in the room and heat absorption of the inner surfaces of walls, intermediate bottoms (ceiling and floor surfaces), parting walls, a formula was obtained to calculate the temperature on the inner surface of the outer corner. Also, through the course of the study, natural tests of the wall structure with an outer corner were carried out and the temperatures on the inner and outer surfaces were obtained. Conclusions. Comparison of the calculation results using the developed engineering calculation method and experimental data showed that the temperatures on the inner surface of the outer corner almost coincided. This makes it possible to use the suggested engineering method for calculating the temperature on the inner surface of the outer wall corner in the design of enclosing structures to exclude condensation.

scholarly journals Accumulation of moisture of cellular concrete wall structures in the annual cycle

2021 ◽  
pp. 55-67
Author(s):  
Veronika Aleksandrovna Shakirova
Keyword(s):  
Annual Cycle ◽  
Construction Materials ◽  
Mineral Wool ◽  
Climatic Conditions ◽  
Wall Structure ◽  
Concrete Wall ◽  
Outdoor Climate ◽  
Wall Structures ◽  
One Year ◽  
Cellular Concrete

This article delivers the calculation of moisture accumulation of the wall structure in the annual cycle for the climatic conditions of Krasnoyarsk. Analysis is conducted on the multilayer wall structure made of cellular concrete, with the plaster based on cement-sand mortar as top layer and use of thermal insulation in the form of mineral wool board. The subject of this research is the typical corner unit made of cellular concrete in combination with monolithic belt and an inter-floor overlap used in low-rise construction. The author acquires the results of moisture accumulation in layers of the structure for each month within one year, depending on the climatic parameters. The novelty lies in the fact that the outdoor climate and sorption moisture influences the accumulation of moisture in construction materials, creating a large seasonal increase in moisture. Consideration of these factors in the design process, allows making the structures more durable and energy-efficient. The conclusion is made that the distribution of moisture structural layers under climatic conditions. Krasnoyarsk is uneven throughout the year; however, meet the regulations. It is recommended to conducted regulation in the design in order to maintain the level of moisture in construction materials

scholarly journals ENGINEERING METHOD FOR CALCULATING THE TEMPERATURE ON THE INNER SURFACE OF THE OUTER CORNER OF A BUILDING

2021 ◽  
pp. 7-19
Author(s):  
N. P. Umnyakova
Keyword(s):  
Outer Wall ◽  
Engineering Calculation ◽  
Engineering Method ◽  
Wall Structure ◽  
Outer Corner ◽  
Wall Structures ◽  
Inner Surface ◽  
Calculation Results ◽  
Floor Surfaces ◽  
The Heat Balance

Statement of the problem. The temperature on the inner surface of the outer corner is always lower than on the inner surface of the outer wall. This temperature difference might lead to the formation of condensation on the inner surface of the wall at low outdoor temperatures. Therefore the problem of developing an engineering method for calculating the temperature in the outer corner to exclude the possibility of condensation on the inner surface in the design process of the outer wall structures is extremely relevant. Results. To address this problem, based on solving the heat balance equation, taking into account the amplitude of air temperature fluctuations in the room and heat absorption of the inner surfaces of walls, intermediate bottoms (ceiling and floor surfaces), parting walls, a formula was obtained to calculate the temperature on the inner surface of the outer corner. Also, during the study, natural tests of the wall structure with an outer corner were carried out and the temperatures on the inner and outer surfaces were obtained.Conclusions. Comparison of the calculation results using the developed engineering calculation method and experimental data showed that the temperatures on the inner surface of the outer corner almost coincided. This makes it possible to use the suggested engineering method for calculating the temperature on the inner surface of the outer wall corner in the design of enclosing structures to exclude the appearance of condensation.

Adaptive changes of the hair coat of the horses of zabaykalsky aborigenous breed

2019 ◽  
Vol 49 (4) ◽  
pp. 101-105 ◽  
Author(s):  
G. M. Shkyratova ◽  
B. Z. Bazaron ◽  
T. N. Khamiruev ◽  
S. M. Dashinimaev
Keyword(s):  
Seasonal Changes ◽  
Climatic Conditions ◽  
Skin Thickness ◽  
Summer Period ◽  
Hair Coat ◽  
Skin Fold ◽  
Winter Grazing ◽  
Shoulder Blade ◽  
Quantitative Indicators

The seasonal changes in the skin thickness and structure of the horses’ coat, as signs of adaptation to environmental factors, were studied. The experiment was carried out with the livestock kept in a herd using winter-grazing technology without additional feedings in the climatic conditions of the Trans-Baikal Territory. The objects of the research were adult mares of Zabaikalsky breed of horses of the same age, class and fatness. The studies were carried out in the middle of each season (May, July, October, February). The length of the coat was measured with a caliper, the coat itself with the determination of the ratio of hair (fl uffy hair, heterotype hair and coarse hair) and the thickness of the skin fold were measured in accordance with the approved methodological recommendations. The minimum skin thickness in winter was detected in mares on the back and shoulder blade – 4.3 and 4.4 mm, the maximum – on the side and thigh – 4.5 4.6 mm. When compared with the summer period, the increase on the side was 0.8 mm, whereas on the back, shoulder blade and thigh – 0.4 mm (p ≤ 0,001). In spring, thickening of the skin was noted within 0.1-0.3 mm in the same topographic areas, compared to autumn. The quantitative indicators of the coat changed depending on the season of the year. In winter, the coat contained more fl uffy hair (23.10%), and less coarse hair (68.24%), in summer there was a lower content of fl uffy hair (4.33%), but more coarse hair (94.01%.) Sharp seasonal changes were noted with regard to the length of the hair. The longest hair was found in winter and spring – 4.96 and 4.26 cm, whereas the shortest – in summer and autumn – 0.94 and 1.90 cm, respectively.

Study on the shear wall structure with combined form of replaceable devices

2017 ◽  
Vol 21 (9) ◽  
pp. 1327-1348
Author(s):  
Cong Chen ◽  
Renjie Xiao ◽  
Xilin Lu ◽  
Yun Chen
Keyword(s):  
Shear Walls ◽  
Shear Wall ◽  
Performance Comparison ◽  
Wall Structure ◽  
Structural Part ◽  
Coupled Shear Wall ◽  
Wall Structures ◽  
Strength And Stiffness ◽  
Energy Dissipated ◽  
Resilient Structure

Structure with replaceable devices is a type of earthquake resilient structure developed to restore the structure immediately after strong earthquakes. Current researches focus on one type of the replaceable device located in the structural part that is most likely to be damaged; however, plastic deformation would not be limited in a specific part but expand to other parts. To concentrate possible damage in shear wall structures, combined form of replaceable devices was introduced in this article. Based on previous studies, combined form of replaceable coupling beam and replaceable wall foot was used in a coupled shear wall. Influences of the dimension and location of the replaceable devices to the strength and stiffness of the shear wall were investigated through numerical modeling, which was verified by experimental data. Performance comparison between the shear walls with one type and combined form of replaceable devices and the conventional coupled shear wall was performed. In general, the shear wall with combined form of replaceable devices is shown to be better energy dissipated, and proper dimensions and locations of the replaceable devices should be determined.

scholarly journals Methacholine responsiveness of proximal and distal airways of monkeys and rats using videomicrometry

2002 ◽  
Vol 92 (3) ◽  
pp. 989-996 ◽  
Author(s):  
Kayleen S. Kott ◽  
Kent E. Pinkerton ◽  
John M. Bric ◽  
Charles G. Plopper ◽  
Krishna P. Avadhanam ◽  
...  
Keyword(s):  
Airway Hyperresponsiveness ◽  
Airway Responsiveness ◽  
Wall Structure ◽  
Airway Closure ◽  
Airway Wall ◽  
Human Airway ◽  
Wall Structures ◽  
Distal Airway ◽  
Luminal Area ◽  
Young Rat

Rat and monkey are species that are used in models of human airway hyperresponsiveness. However, the wall structures of rat and monkey airways are different from each other, with that of the monkey more closely resembling that of humans. We hypothesized that differences in wall structure would explain differences in airway responsiveness. Using videomicrometry, we measured airway luminal area in lung slices to compare proximal and distal airway responsiveness to methacholine in the rat and monkey. The airway type was then histologically identified. Proximal airways of the young rat and monkey were equally responsive to methacholine. In contrast, respiratory bronchioles of monkeys were less responsive than were their proximal bronchi, whereas the distal bronchioles of rats were more responsive than their proximal bronchioles. Both proximal and distal airways of younger monkeys were more responsive than those of older monkeys. Airway heterogeneity in young monkeys was greatest with regard to degree of airway closure of respiratory bronchioles. We conclude that responsiveness to methacholine varies with airway wall structure and location.

scholarly journals Heat flow distribution and thermal structure of the Nankai subduction zone off the Kii Peninsula

2011 ◽  
Vol 12 (10) ◽  
pp. n/a-n/a ◽  
Author(s):  
Hideki Hamamoto ◽  
Makoto Yamano ◽  
Shusaku Goto ◽  
Masataka Kinoshita ◽  
Keiko Fujino ◽  
...  
Keyword(s):  
Heat Flow ◽  
Subduction Zone ◽  
Thermal Structure ◽  
Flow Distribution ◽  
Kii Peninsula ◽  
Nankai Subduction Zone
Sign in / Sign up

Export Citation Format

Share Document