scholarly journals Impact analysis of humidity and temperature on the value of thermal conductivity λ coefficient of insulating materials used inside buildings

2013 ◽  
Vol 12 (4) ◽  
pp. 165-176
Author(s):  
Maciej Trochonowicz ◽  
Beata Witek ◽  
Marcin Chwiej
Keyword(s):  
Thermal Conductivity ◽  
Laboratory Tests ◽  
Impact Analysis ◽  
Insulating Materials ◽  
Coefficient Of Thermal Conductivity ◽  
Temperature And Humidity ◽  
Specific Temperature ◽  
Materials Used ◽  
Thermal Conductivity Λ ◽  
Cellular Concrete

The aim of the article is to present the issues related to the use of climate panels as insulating materials used inside buildings. The study involved four materials, the two of them is a lightweight cellular concrete, the other two were produced on the basis of lime silicate. The main aim of the laboratory tests was to determine the coefficient of thermal conductivity λ depending on the changing temperature and humidity. Based on research the sorption materials curves were determined. The study allows you to specify the amount of moisture that can be accepted by the material in specific temperature and humidity conditions. In addition, the examined coefficients of thermal conductivity compared with the values declared by suppliers to assess compliance with the data contained in the data sheet.

scholarly journals Zastosowanie stanowiska pomiarowego do badań przewodnictwa cieplnego materiałów budowlanych metodą „gorącego drutu”

2019 ◽  
Vol 28 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Karol Prałat ◽  
Justyna Ciemnicka ◽  
Mirosław Grabowski ◽  
Roman Jaskulski ◽  
Wojciech Kubissa
Keyword(s):  
Thermal Conductivity ◽  
Experimental Research ◽  
Sampling Time ◽  
Measuring System ◽  
Hot Wire ◽  
Measuring Converter ◽  
Voltage Output ◽  
Coefficient Of Thermal Conductivity ◽  
Wire Method ◽  
Thermal Conductivity Λ

Results of experimental research have been presented in this article, determining the coefficient of thermal conductivity (λ) of gypsum. During measurements, a “hot wire” method was used, which belongs to the most interesting method because of its simplicity, easiness of realization and precision. Platinum Pt100 sensor was used during measurements, which both with measuring system creates precise temperature measuring converter with voltage output. Measurements were registered with the help of computer measuring system, with sampling time every 0.01 s.

scholarly journals Influence of hydrophilic polymers based on polyvinyl alcohol and starch on physiсo-mechanical properties of thermal insulation materials

2020 ◽  
pp. 32-38
Author(s):  
Perizat Urkimbaeva ◽  
Bauyrzhan Bakytzhanuly ◽  
Yesen Dilmukhambetov ◽  
Alua Mamutova ◽  
Zarina Kenessova
Keyword(s):  
Thermal Conductivity ◽  
Polyvinyl Alcohol ◽  
Linear Shrinkage ◽  
Natural Polymers ◽  
Insulating Materials ◽  
Thermal Insulating ◽  
Coefficient Of Thermal Conductivity ◽  
Almost All ◽  
Positive Effect ◽  
Synthetic And Natural Polymers

Thermal insulating materials based on diatomite with burnable and reinforcing additives modified with synthetic and natural polymers have been developed. A mixture of polyvinyl alcohol and starch was used as modifying polymers. The parameters of linear shrinkage, density, tensile strengths in compression and bending, as well as the coefficient of thermal conductivity of the material were determined depending on the concentration and ratio of polymers. It was established that polymer additives had a positive effect on almost all specified characteristics of thermal insulating materials. For example, when adding polymers up to 1 mass.%, the linear shrinkage coefficients decrease from 14.5 to 4.5%, the ultimate compression strengths increase from 0.22 to 2.51 MPa, the ultimate bending strengths increase from 0.2 to 1.26 MPa, the coefficients of thermal conductivity decrease from 0.068 to 0.049 W/m∙K. The densities of materials are in the range of 0.592-0.491 g/cm3. The results of the work showed that the obtained heat-insulating materials can be used as plasticizers in the field of thermal energy.

Development of Thermal Insulation Composite Material from Recycled Polymer and Recycled Glass

2012 ◽  
Vol 487 ◽  
pp. 701-705 ◽  
Author(s):  
Jan Pěnčík ◽  
Libor Matějka ◽  
Alena Kalužová ◽  
Libor Matějka ◽  
Darina Dostálová ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Thermal Insulation ◽  
Static Load ◽  
Sustainable Construction ◽  
Mechanical Resistance ◽  
Recycled Glass ◽  
Coefficient Of Thermal Conductivity ◽  
Structural Details ◽  
Materials Used

With the sustainable construction the emphasis is placed on saving energy, reducing of consumption of natural resources, extending the life cycle of recycling, etc. One of the important groups of waste materials that can be reused are waste polymers. These materials are used in the design of thermal insulation composite material. The crucial property of materials used for thermal insulation is the coefficient of thermal conductivity. Thermal conductivity coefficients of waste polymers however do not meet the requirements. For this reason, waste polymers are within the development of thermal insulation composite material combined with filler with a low coefficient of thermal conductivity. In developing of this composite material the developers combine a method of theoretically optimized software design of blends with their production and experimental verification. Possibility of application of thermal insulation composite material can be seen especially in the structural details, in which it is necessary to eliminate the thermal bridges, but also details where the requirements are applied to the mechanical resistance and static load bearing capacity.

scholarly journals The impact of temperature, humidity and the direction of analysis on thermal conductivity λ in different types of wood

2015 ◽  
Vol 14 (4) ◽  
pp. 149-156 ◽  
Author(s):  
Maciej Trochonowicz ◽  
Nina Kołodziejczuk
Keyword(s):  
Thermal Conductivity ◽  
Laboratory Test ◽  
Building Structure ◽  
Different Types ◽  
Temperature And Humidity ◽  
The Impact ◽  
Thermal Conductivity Λ

The main aim of the article is to present the issues related to the impact of temperature and humidity on thermal conductivity  in different types of wood used in building structure. In this elaboration authors present the results of laboratory test. Authors checked the impact of the direction of analysis and density of wood on thermal conductivity  in wooden elements.

scholarly journals Heat radiation effects on insulating materials used in buildings

2021 ◽  
Author(s):  
Flóra Hajdu ◽  
Gabriella Lászlo ◽  
Rajmund Kuti
Keyword(s):  
Thermal Insulation ◽  
Laboratory Tests ◽  
Radiation Effects ◽  
Expanded Polystyrene ◽  
Heat Radiation ◽  
Insulation Material ◽  
Insulating Materials ◽  
Insulation Materials ◽  
Materials Used ◽  
Construction Permit

AbstractIn recent years, in order to increase the energy efficiency of older buildings in Hungary, several tenders have supported the modernization of the thermal insulation. Various thermal insulation materials have been installed on walls, on slab and on floor. Unfortunately there are cases where thermal insulation materials are not installed in accordance with the construction permit or the manufacturer’s instructions, which poses a serious danger in case of a fire. During the research the effects of heat on the behavior of Expanded PolyStyrene, a thermal insulation material often used in Hungary is examined. Laboratory tests and computer simulations were carried out, which are presented in detail in this paper. The aim of the research is to contribute to increase the fire safety of buildings.

scholarly journals A new method for thermal conductivity measurement: application to complex heterogeneous materials used in thermal batteries

2021 ◽  
Vol 2116 (1) ◽  
pp. 012041
Author(s):  
T Ledevin ◽  
M William-Louis ◽  
L Courty ◽  
D Fabre ◽  
L Faget
Keyword(s):  
Thermal Conductivity ◽  
Heterogeneous Materials ◽  
Conductivity Measurement ◽  
Phase Shifts ◽  
Experimental Measurements ◽  
Thermal Signal ◽  
Thermal Batteries ◽  
Different Temperatures ◽  
Materials Used ◽  
Thermal Conductivity Λ

Abstract The thermal conductivity of heterogeneous materials used in thermal batteries is difficult to measure. These materials must be handled under controlled atmosphere with methods adapted to their porous nature. The method presented in this work uses heating plates to send a sinusoidal thermal signal to the tested sample. The whole setup is confined in a glovebox to ensure the composition and hygrometry of the atmosphere. Parametric computer simulations with varying thermal conductivity (λ) of the sample and thermal resistance (h) of the contacts as inputs were performed to calculate the phase shifts associated with two thicknesses of the sample. Experimental measurements of phase shifts on these two configurations allowed the identification of the only couple (λ,h) which matches the phase shifts on the respective thicknesses. This method is validated using the reference material BK7 at different temperatures. Thermal conductivities of a heterogeneous cathode used in thermal batteries is also given using this method.

scholarly journals The use of materials based on Si3N4 in the composition of composites for the design of high-temperature thermoelectric generators

2020 ◽  
pp. 7-14
Author(s):  
V.V. Tsygoda ◽  
V.Ya. Petrovskiy
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Figure Of Merit ◽  
Negative Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Generators ◽  
Thermoelectric Figure ◽  
Coefficient Of Thermal Conductivity ◽  
Materials Used ◽  
First Time

The possibility of reducing the thermal conductivity of silicon nitride as a basis of high-temperature electrical converters was investigated in the thesis. Also, the values of thermoelectric figure of merit and efficiency of thermoelectric current generator for the case of refractory oxygen-free composites were simulated. During the study, the dependence between the m coefficient, which determines the maximum possible efficiency of the thermoelectric generator and the ZT thermoelectric figure of merit, was determined. It was shown that the coefficient of thermal conductivity of the studied materials ranges from 1,2 to 4·106 m2/s and is characterized by a negative temperature coefficient over the entire temperature range. It was found that the thermal conductivity of Si3N4-based materials varies from 2,1 to 5,1 W/(m·K) depending on the type of sintering activator. The use of Al2O3 as an activator makes it possible to obtain a 25% lower thermal conductivity value comparing to materials with the addition of MgO. For the first time, it was proved that currently it is not possible to achieve an efficiency of 0,5hT in Si3N4-based materials used as a composite basis for high-temperature thermoelectric generators development.

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