METHOD OF CALCULATION OF THERMAL PROPERTIES FOR BUILDING ENVELOPES WITH SCREEN INSULATION

2016 ◽  
Vol 6 (1) ◽  
pp. 4-7 ◽  
Author(s):  
Yuri Serafimovich VYTCHIKOV ◽  
Mikhail Evgen'evich SAPAREV
Keyword(s):  
Thermal Properties ◽  
Thermal Conduction ◽  
Numerical Data ◽  
Engineering Practice ◽  
Building Envelopes ◽  
Method Of Calculation ◽  
Thermal Screen ◽  
Air Ventilation ◽  
Resources Conservation ◽  
The Moment

The present research is performed in the framework of energy and resources conservation measures promotion in civil engineering. It introduces the perspectives of using thermal isolation in outer building envelopes and in air ventilation and conditioning systems insulation. The paper analyses the use of thermal screen isolation in building envelopes and air ventilation systems and proves that at the moment there is no methodology able to calculate these constructions in the existing engineering practice. The authors conducted a physical experiment to get reliable data on thermal screen isolation properties taking expanded polyethylene as a sample material. The results of the experiment as well as the obtained thermal conduction coefficient are presented in the paper. On the basis of the numerical data the authors introduce a verified methodology of calculation of thermal properties for building envelopes with screen insulation.

scholarly journals HEAT RESISTANT BUILDING ENVELOPES MADE OF LIGHTWEIGHT CONCRETE WITH THE USE OF POROUS GRANULAR WASTES

2017 ◽  
Vol 3 ◽  
pp. 53
Author(s):  
S. Ya. Galitskov ◽  
S. A. Mizuryaev ◽  
A. G. Chiknovoryan
Keyword(s):  
Lightweight Concrete ◽  
Crystallographic Analysis ◽  
Building Construction ◽  
Oil Refining ◽  
Chemical Compositions ◽  
Building Envelopes ◽  
Heat Resistant ◽  
High Thermal Resistance ◽  
The Republic ◽  
The Moment

The paper focuses on building envelopes for industrial thermal generating units, their efficiency and its increase. Building envelopes made of lightweight heat-resistant concretes are considered most effective from the point of their building construction, maintenance, repair and cost-effectiveness. One of the unresolved problems here is that porous granular materials suitable for use as concrete fillers operating at temperatures over 1000 OC are not industrially manufactured at the moment The article also characterises commonly used heat resistant porous fillers. It indicates that the use of exhaust zeolites is potentially perspective General properties and characteristics of zeolites are also given. The paper demonstrates that it is quite possible to use exhaust zeolites in building envelopes of lightweight heat-resistant concretes. The work describes testing experiments of typical exhaust zeolites (petrochemical and oil refining industries wastes) in Samara region and the Republic of Tatarstan. Their stress-strain properties and chemical compositions as well as X-ray crystallographic analysis (including analysis under high temperature) are presented. They prove that zeolites are heat-resistant and fire-proof because of corundum formation. Phosphate binder was used for tesing in heat-resistant concretes. The composition of the concrete mixture is given in the paper. As a result, concrete with the following characteristics was obtained: 1550 kg/m3 density, with compressive strength of approximately 21 MPa, having high thermal resistance and maximum permissible application temperature of 1450° c.

Thermal Properties Analysis of Several N-Alkanes Eutectic Mixtures Applied in Building Envelopes

2012 ◽  
Vol 512-515 ◽  
pp. 3007-3010
Author(s):  
Jing Yu Huang ◽  
Shi Lei Lv ◽  
Chen Xi Zhang ◽  
Zhi Wei Wang
Keyword(s):  
Thermal Properties ◽  
Melting Temperature ◽  
Latent Heat ◽  
Heat Storage ◽  
Eutectic Mixture ◽  
Scanning Calorimetry ◽  
Latent Heat Storage ◽  
Building Envelopes ◽  
Eutectic Mixtures ◽  
Change Material

This study focuses on the preparation, thermal properties of alkanes eutectic mixtures (n-Octadecane/n-Eicosane, n-Octadecane/n-Docosane and n-Heptadecane /n-Eicosane) as candidate phase change material (PCM) for low temperature latent heat storage systems in building envelopes. Their melting temperature and latent heat were tested by Differential scanning calorimetry (DSC). The testing values were closed to calculation values of accepted theory that ensured the reliability of those datas. The results indicated n-Octadecane/n-Docosane eutectic mixture was more promising PCM for buildings in terms of melting temperature (25.3°C) and latent heat values of melting (158.2J/g).

scholarly journals Relationship Between Dynamic Thermal Properties, Energy Consumption and Comfort with Different Building Envelopes in a Canadian Building

2020 ◽  
Author(s):  
Alexandre Pépin ◽  
Louis Gosselin ◽  
Jonathan Dallaire
Keyword(s):  
Heat Capacity ◽  
Thermal Properties ◽  
Energy Consumption ◽  
Important Variable ◽  
Office Building ◽  
Quebec City ◽  
Thermal Mass ◽  
Building Envelopes ◽  
Heating And Cooling ◽  
Energy Intensities

An office building located in Quebec City (Canada) with different envelope assemblies has been simulated in order to determine the energy consumption and thermal comfort that they provide. The resistance, thermal mass, and materials (concrete, cross-laminated timbers (CLT), and light-frame) are varied in a series of 164 different scenarios and the energy intensities for heating and cooling determined in each case, along with the discomfort index. Results show that the materiel used to provide thermal mass has a larger impact on comfort and energy consumption than the value of the thermal mass thickness itself. It was also attempted to correlate the performance of the envelope and its thermal mass with three dynamic thermal properties (i.e., dynamic transmittance, areal heat capacity, and decrement factor). Apart from thermal resistance, the internal areal heat capacity appeared to be the most important variable to explain variations of performance of the envelope.

scholarly journals The calculation of variable heat flow in solids

1946 ◽  
Vol 240 (813) ◽  
pp. 1-57 ◽  
Keyword(s):  
Thermal Properties ◽  
Heat Flow ◽  
Analytical Solutions ◽  
Numerical Evaluation ◽  
Formal Solution ◽  
Industrial Processes ◽  
Laboratory Work ◽  
Engineering Practice ◽  
Direct Experiment ◽  
Variable Heat Flow

In many contexts, in laboratory work, in industrial processes and in engineering practice, situations arise in which it is required to determine the flow of heat in bodies under nonsteady conditions. In some cases this can be done by direct experiment, and a few cases are sufficiently simple for formal analytical solutions of the appropriate equations to be obtained and evaluated. But direct experiment is often difficult or impossible, especially under practical conditions of manufacture or operation; and often the conditions of the problem, such as inhomogeneity or the shape of the material, or variation of its thermal properties with temperature, either make the formal solution so complicated that its numerical evaluation is impracticable, or put a formal solution out of the question altogether.

Dynamic Thermal Properties of Uninsulated Rammed Earth Building Envelopes

2013 ◽  
Vol 855 ◽  
pp. 85-88 ◽  
Author(s):  
Miloslav Bagoňa ◽  
Clayton Stone ◽  
Jozef Šimiček
Keyword(s):  
Thermal Properties ◽  
Rammed Earth ◽  
Conductive Heat ◽  
Climate Data ◽  
Climate Chamber ◽  
Building Envelopes ◽  
Transfer Processes ◽  
Australian Climate ◽  
Building Components

The paper demonstrates the thermal admittance procedure as a technique to quantify the dynamic thermal properties of two uninsulated rammed earth building components subjected to radiative and conductive heat transfer processes. With the aid of Australian climate data and a climate chamber, this research paper uses a dynamic thermal property calculator developed by Arup in accordance with EN ISO 13786:2007 to quantify the performance of a homogenous rammed earth envelope subjected to in-situ measurements that mimic real conditions.

scholarly journals Microwave Absorption in Layered Media: Application to Landmine Detection

2000 ◽  
Vol 53 (5) ◽  
pp. 723 ◽  
Author(s):  
J. A. Hermann
Keyword(s):  
Thermal Properties ◽  
Microwave Absorption ◽  
Time Evolution ◽  
Microwave Radiation ◽  
Thermal Energy ◽  
Thermal Conduction ◽  
Landmine Detection ◽  
Composite Media ◽  
Conduction Model ◽  
One Dimensional

The absorption of microwave radiation and subsequent thermal conduction by simple composite media, consisting of parallel layers with disparate thermal properties,is analysed.The solutions for a one-dimensional conduction model are used to investigate the time evolution and distribution of thermal energy within moisture-laden soils containing non-absorbing objects.The application of these results to the detection of landmines is discussed and evaluated.

scholarly journals Hazard forecasting techniques implementation in crane safety instruments using a crane anemometer

2020 ◽  
Vol 17 (5) ◽  
pp. 584-597
Author(s):  
V. A. Roshchin ◽  
S. D. Ivanov ◽  
A. N. Nazarov
Keyword(s):  
Wind Speed ◽  
Main Part ◽  
Technical Documentation ◽  
Average Wind Speed ◽  
Method Of Calculation ◽  
Average Wind ◽  
Pulse Sensor ◽  
The Moment ◽  
Average Wind Velocity ◽  
Technical Centre

Introduction. This article describes an algorithm developed by the authors for the operation of a crane anemometer that measures the gust rate and average wind speed and determines the predicted wind speed on the basis of it. The main part. The main influencing parameters and their measurement intervals are defined for the construction of the anemometer algorithm. The method of calculation of gust velocity and average wind velocity from the data of the pulse sensor of the helicopter anemometer is presented. The method of wind speed forecasting based on the construction of an extrapolation function is given.Results. An anemometer program algorithm with extended capabilities relative to existing analogues has been developed. The instrument not only captures the hazard at the moment, but also predicts its future development. On the basis of the analysis of wind dynamics studies, a table has been compiled of the levels of the determined parameters (gust rate, average speed and projected average wind speed) and the signals given to the operator of the crane. For each type of signal, the value of the removal delay is defined.Conclusions. ZAO KROS Engineering and Technical Centre has made a prototype anemometer using the principles described in this article. The device meets all requirements of the regulatory and technical documentation. Further work on the improvement of the algorithm of its work will make it possible to increase the safety of technological processes carried out with the use of elevated structures.

scholarly journals Bending of Symmetric Sandwich FGM Beams with Shear Connectors

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Dung Nguyen Thai ◽  
Phung Van Minh ◽  
Cuong Phan Hoang ◽  
Tam Ta Duc ◽  
Nhung Nguyen Thi Cam ◽  
...  
Keyword(s):  
Finite Element ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Beam Theory ◽  
Numerical Data ◽  
Functionally Graded ◽  
Engineering Practice ◽  
Graded Materials ◽  
Shear Connectors ◽  
The Impact

This paper carries out the static bending analysis of symmetric three-layer functionally graded sandwich beams, in which each layer is made from different functionally graded materials, and they are connected by shear connectors due to sliding movement. The finite element formulations are based on Timoshenko’s first-order shear deformation beam theory (FSDT) and the finite element method to establish the equilibrium equation of beams. The calculation program is coded in the MATLAB environment, and then verification examples are given out to compare the numerical data of present work with those of exact open sources. The impact of several geometrical and material parameters on the mechanical response of the structure, such as the height-to-length ratio, boundary conditions, volume fraction index, and especially the shear coefficient of connectors, is being explored. When designing and using these types of structures in engineering practice, the computed results can be utilized as a valid reference.

Heat Conduction of Fixator Pins with Polymethylmethacrylate External Fixation

1997 ◽  
Vol 10 (03) ◽  
pp. 153-159 ◽  
Author(s):  
J. L. Tomlinson ◽  
A. W. Hahn ◽  
G. M. Constantinescu ◽  
Colette Wagner-Mann ◽  
N. Williams
Keyword(s):  
Thermal Properties ◽  
Heat Conduction ◽  
External Fixation ◽  
Thermal Conduction ◽  
Thermal Injury ◽  
Animal Health ◽  
External Fixators ◽  
University Of Missouri ◽  
The University ◽  
Honor Society

SummaryThe purpose of this study was to determine the degree of thermal conduction along the fixation pins associated with acrylic external fixators and to develop a means of minimizing the potential for thermal injury. The data suggest that the degree of temperature conducted with 1.9 cm diameter acrylic external fixators was of minimal clinical significance if maintained a distance of one centimeter from the patient’s tissues. Larger diameter columns increase the potential for injury, however, this can be minimized with the use of a constant saline drip at the pin-acrylic interface to facilitate heat loss.This article describes the evaluation of thermal properties of polymethylmethacrylate external skeletal fixators. The data demonstrate heat conduction along the fixation pins. Thermal injury is theoretically minimized if columns are maintained a distance of at least one centimeter from the patient’s tissue.Research supported in part by and presented for the University of Missouri Pi Chapter of the Honor Society of Phi Zeta in coordination with SmithKline Beecham Animal Health, April 7, 1994

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