scholarly journals DETERMINATION OF THE OPTIMAL PARAMETERS OF THE HEAT-SHIELDING PROPERTIES OF NATURAL AND SYNTHETIC FILLERS FOR CHILDREN'S OUTERWEAR PRODUCTION

2019 ◽  
pp. 170-180
Author(s):  
Iraida Dudla ◽  
◽  
Olena Khrebtan ◽  
Keyword(s):  
Heat Transfer ◽  
Surface Density ◽  
Optimal Parameters ◽  
Target Setting ◽  
Textile Materials ◽  
Mathematical Equations ◽  
Shielding Properties ◽  
Heat Shielding ◽  
Natural And Synthetic

Urgency of the research. The main functional property of children's outerwear is a heat-shielding property. The research of the heat-shielding properties of natural and synthetic fillers for children's outerwear production is quite multifaceted, complex and insufficiently studied question. This is due to the fact that for the manufacture of children's outerwear new fabrics for the top and lining, as well as fillers of various materials are used. Target setting. Determination of the optimal parameters of the heat-shielding properties of natural and synthetic fillers for children's outerwear production is an important task, since the greatest value of clothing is for the processes of heat exchange of the human body with the environment and to ensure normal thermoregulation. Actual scientific researches and issues analysis. Considerable attention has been paid to the prediction of the heatprotective properties of winter clothing or its construction, the substantiation of the choice of a package of materials for the manufacture of children's outerwear, mathematical modelling of the heat transfer through textile materials and to the physical model of thermal resistance determination. Uninvestigated parts of general matters defining. The heat-shielding properties of natural and synthetic fillers for the outerwear of children are practically not studied, and the calculations of the optimal parameters of these properties are fragmentary. The research objective. to determine the optimal parameters of the heat-shielding properties of natural and synthetic fillers for children's outerwear production. The statement of basic materials. It was found that the heat-shielding properties of children's jackets with feather-down and synthetic textile filler depend on the type of filler, thickness, surface density and breathability of the clothing package. Conclusions. Children's jackets with feather-down filler with a smaller thickness have the lowest level of breathability, which provides them with the best heat-shielding properties. The higher level of breathability inherent in a children's jacket with synthetic textile filler with a significantly greater thickness of the package can provide high levels of the heat-shielding properties. Mathematical equations to determine the optimal parameters of the heat-shielding properties of natural and synthetic fillers for children's outerwear production are suggested.

scholarly journals CHANGES IN LIGHTING STANDARDS AND THEIR INFLUENCE ON THE ARCHITECTURE AND ENERGY EFFICIENCY OF MODERN RESIDENTIAL BUILDINGS

2020 ◽  
pp. 9-17
Author(s):  
E.V. Vitvitskaya ◽  
◽  
D.V. Tarasevich ◽  
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Energy Savings ◽  
Residential Buildings ◽  
Residential Building ◽  
High Heat ◽  
Transfer Resistance ◽  
Heating And Cooling ◽  
Shielding Properties ◽  
Heat Shielding

Abstract. State regulations on the design of lighting in residential buildings in recent years have undergone significant changes, which in turn will significantly affect the architecture and energy efficiency of modern buildings of this type. This can be observed from the authors' analysis of the change in only one regulatory document given in this article – SCS (State Construction Standards) V.2.5-28: «Natural and artificial lighting» and only one lighting indicator: permissible deviation of the calculated value of CNL (coefficient of natural lighting) from the standardized value when choosing translucent structures of buildings. This article presents an analysis of this normative document in two versions – in the old one from 2012 and new from 2018. Based on the results of the analysis, the authors of this article found that, at the request of the architect, the area of translucent structures on the facades of two identical modern residential buildings can differ significantly: from the minimum with piece (separate) windows on the facades – where glazing occupies from 14.3% to 18.3% of the area of the facades; up to maximum with continuous glazing of facades – where glazing occupies up to 100% of the area of the facades of a residential building. These two facade glazing options are not only architecturally perceived differently, but they must also have different energy efficiency in order to provide different minimum allowable values of heat transfer resistance: for piece (individual) windows on the facade, this is R∑ ≥ Rq min = 0.6 m2•K/W and ordinary silicate glasses are suitable for their glazing, and for continuous glazing of the facade this should already be R∑ ≥ Rq min = 2.8 m2•K/W, that is, they must have the same heat-shielding properties as the outer walls, and their minimum allowable value of the heat transfer resistance must be 4.66 times more than for piece (separate) windows. For this option, ordinary silicate glass is no longer suitable, but modern glass-transparent structures with high heat-shielding properties should be used, for example Qbiss_Air, Pilkington, Heat Mirror Glass and others. They provide excellent protection against hypothermia in winter and overheating in summer, and have good sun protection properties. Their use in modern buildings contributes to energy savings for heating and cooling rooms throughout the year and creates increased comfort, but such translucent structures are much more expensive and better suited for elite housing construction than for social.

OPTIMIZATION OF HEAT-SHIELDING CHARACTERISTICS OF THE EXTERIOR WALLS OF COUNTRY COTTAGES, INSULATED WITH MONOLITHIC FOAM CONCRETE

2018 ◽  
Vol 8 (3) ◽  
pp. 22-25
Author(s):  
Yury S. VYTCHIKOV ◽  
Mikhail Ye. SAPAREV ◽  
Vladislav A. GOLIKOV
Keyword(s):  
Heat Transfer ◽  
Outer Wall ◽  
Heating Time ◽  
Exterior Wall ◽  
Foam Concrete ◽  
Transfer Resistance ◽  
Warm Up ◽  
Shielding Properties ◽  
Heat Shielding ◽  
Resistance To Heat

The heat-shielding properties of three-layer external walls insulated with monolithic foam concrete are considered in the article. The temperature is given in rooms operated in intermitt ent heating conditions. An optimal exterior wall design is proposed using monolithic foam concrete for the construction of country cott ages. For this design, the results of heat engineering calculations are presented using the analytical dependence of determining the heat transfer resistance, which ensures the minimum warm-up time of the wall. The results of the calculation are presented in tabular form for a given heating time and density of foam concrete. Also a relationship is described to determine the maximum allowable resistance to heat transfer of the outer wall at diff erent densities of monolithic foam concrete.

INFLUENCE OF HEAT TREATMENT OF MOUNTAIN MASSIVE ON TEMPERATURE MODE OF GEOTHERMAL CIRCULATION SYSTEM

2018 ◽  
pp. 44-50
Author(s):  
Yu. P. Morozov
Keyword(s):  
Heat Transfer ◽  
Operating Time ◽  
Fluid Motion ◽  
Coolant Temperature ◽  
Circulation System ◽  
Thermal Processes ◽  
Temperature Mode ◽  
Heat Influx ◽  
Stationary Heat Transfer

Based on the solution of the problem of non-stationary heat transfer during fluid motion in underground permeable layers, dependence was obtained to determine the operating time of the geothermal circulation system in the regime of constant and falling temperatures. It has been established that for a thickness of the layer H <4 m, the influence of heat influxes at = 0.99 and = 0.5 is practically the same, but for a thickness of the layer H> 5 m, the influence of heat inflows depends significantly on temperature. At a thickness of the permeable formation H> 20 m, the heat transfer at = 0.99 has virtually no effect on the thermal processes in the permeable formation, but at = 0.5 the heat influx, depending on the speed of movement, can be from 50 to 90%. Only at H> 50 m, the effect of heat influx significantly decreases and amounts, depending on the filtration rate, from 50 to 10%. The thermal effect of the rock mass with its thickness of more than 10 m, the distance between the discharge circuit and operation, as well as the speed of the coolant have almost no effect on the determination of the operating time of the GCS in constant temperature mode. During operation of the GCS at a dimensionless coolant temperature = 0.5, the velocity of the coolant is significant. With an increase in the speed of the coolant in two times, the error changes by 1.5 times.

APPLICATION OF ADSORPTION METHOD FOR DETERMINATION OF LOCAL CONVECTIVE HEAT TRANSFER RATES

1974 ◽  
Author(s):  
S. Koncar-Djurdjevic ◽  
M. Mitrovic ◽  
S. Cvijovic ◽  
G. Popovic ◽  
Dimitrije Voronjec
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Adsorption Method ◽  
Transfer Rates
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