Experimental Determination of Thermal Properties of Highly Viscous Liquids

2014 ◽  
Vol 1041 ◽  
pp. 39-42
Author(s):  
Petra Vojkůvková ◽  
Ondřej Šikula
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Experimental Determination ◽  
Direct Method ◽  
Energy Performance ◽  
Viscous Fluids ◽  
Heating And Cooling ◽  
Set Up

This contribution deals with experimental determination of thermal properties needed for transient heat transfer calculation by conduction in highly viscous fluids; which are the density, thermal conductivity and specific heat capacity. Density was determined by direct method, heat capacity was measured with mixing calorimeter and thermal conductivity was studied with two different measuring equipments. Experimental set up for determination of thermal conductivity was designed and constructed by the author. Results were corrected by numerical simulations in CalA software. All measurement quantities were compared with calculations based on the chemical composition of the substance. The determined thermal properties can be used for calculation of energy performance of heating and cooling of highly viscous fluids.

scholarly journals Testing a Gypsum Composite Based on Raw Gypsum with a Direct Admixture of Paraffin and Polymer to Improve Thermal Properties

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3241
Author(s):  
Krzysztof Powała ◽  
Andrzej Obraniak ◽  
Dariusz Heim
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Phase Change ◽  
Large Scale ◽  
Building Materials ◽  
Residential Buildings ◽  
Energy Performance ◽  
Polymer Content ◽  
Volumetric Heat Capacity

The implemented new legal regulations regarding thermal comfort, the energy performance of residential buildings, and proecological requirements require the design of new building materials, the use of which will improve the thermal efficiency of newly built and renovated buildings. Therefore, many companies producing building materials strive to improve the properties of their products by reducing the weight of the materials, increasing their mechanical properties, and improving their insulating properties. Currently, there are solutions in phase-change materials (PCM) production technology, such as microencapsulation, but its application on a large scale is extremely costly. This paper presents a solution to the abovementioned problem through the creation and testing of a composite, i.e., a new mixture of gypsum, paraffin, and polymer, which can be used in the production of plasterboard. The presented solution uses a material (PCM) which improves the thermal properties of the composite by taking advantage of the phase-change phenomenon. The study analyzes the influence of polymer content in the total mass of a composite in relation to its thermal conductivity, volumetric heat capacity, and diffusivity. Based on the results contained in this article, the best solution appears to be a mixture with 0.1% polymer content. It is definitely visible in the tests which use drying, hardening time, and paraffin absorption. It differs slightly from the best result in the thermal conductivity test, while it is comparable in terms of volumetric heat capacity and differs slightly from the best result in the thermal diffusivity test.

scholarly journals Novel Dual Walling Cob Building: Dynamic Thermal Performance

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7663
Author(s):  
Kaoutar Zeghari ◽  
Ayoub Gounni ◽  
Hasna Louahlia ◽  
Michael Marion ◽  
Mohamed Boutouil ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Water Content ◽  
Wheat Straw ◽  
Numerical Study ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Structural Walls ◽  
Hemp Shiv

This paper emphasizes the experimental and numerical study of new cob mixes used for insulation and load bearing wall elements. The experimental study provides complete datasets of thermal properties of the new walling materials, using cob with density ranging from 1107 kg/m3 to 1583 kg/m3 for structural walls and less than 700 kg m−3 for insulation walls. Various mixes of French soils and fibres (reed, wheat straw, hemp shiv, hemp straw, and flax straw) with different water contents are studied. The lowest average thermal conductivity is obtained for the structural cob mix prepared of 5% wheat straw and 31% of water content. The insulation mix, prepared with 25% reed and 31% water content, has the lowest thermal conductivity. Investigation of diffusivity, density, and heat capacity shows that, when thermal conductivity is lower than 0.4 W m−1 K−1, the decrease in cob density leads to better insulation values and higher heat capacity. Little variation is noticed regarding the density and heat capacity for cob mixes with thermal conductivity higher than 0.4 W m−1 K−1. Furthermore, the non-uniformity of local thermal conductivity and heat losses through the samples is due mainly to the non-uniform distribution of fibres inside the mixes inducing an increase in heat loss up to 50% for structural walls and 25% for insulation walls. Cob thermal properties are used in a comparative simulation case study of a typical house under French and UK climatic conditions. The energy performance of the conventional building is compared to a dual walled cob building, showing remarkable reduction in energy consumption as the cob walls, whilst maintaining comfortable indoor conditions without additional heating.

Equipment for the Experimental Determination of Thermal Properties of Fluids at Elevated Pressures

1972 ◽  
Vol 94 (4) ◽  
pp. 757-764 ◽  
Author(s):  
P. R. Bishnoi ◽  
D. B. Robinson
Keyword(s):  
Heat Capacity ◽  
Thermal Properties ◽  
Heat Exchanger ◽  
Experimental Determination ◽  
High Pressures ◽  
Heat Capacities ◽  
Compressible Fluids ◽  
Flow Calorimetry ◽  
Elevated Pressures

The available methods for determining the thermal properties of compressible fluids by flow calorimetry are reviewed and an analysis is given for the method of determining heat capacity ratios by passing the fluid at low and high pressures through a heat exchanger. The design of the heat exchanger calorimeter and its associated equipment are described in detail. The performance of the equipment in determining the heat capacities of nitrogen was evaluated at temperatures of 60.2, 75.7, and 150.4 deg C and at pressures up to 2200 psi. The results were compared where possible with those of other workers. Agreement was within about ±0.5 percent which is the anticipated accuracy of the method.

scholarly journals Numerical and experimental determination of the thermal conductivity of pristine and substituted Fe2VAl

2021 ◽  
pp. 160828
Author(s):  
Martin S. Talla Noutack ◽  
Abou Diack-Rasselio ◽  
Eric Alleno ◽  
Philippe Jund
Keyword(s):  
Thermal Conductivity ◽  
Experimental Determination

Experimental determination of the thermal conductivity of molten pure salts and salt mixtures

1985 ◽  
Vol 6 (4) ◽  
pp. 315-330 ◽  
Author(s):  
R. Tufeu ◽  
J. P. Petitet ◽  
L. Denielou ◽  
B. Le Neindre
Keyword(s):  
Thermal Conductivity ◽  
Experimental Determination ◽  
Salt Mixtures

Determination of the Thermal Properties of a PCB by Coupled Numerical and Experimental Approach

2020 ◽  
Author(s):  
Yener Usul ◽  
Mustafa Özçatalbaş
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Numerical Analysis ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermal Analyses ◽  
Analysis Model ◽  
Linear Temperature ◽  
Coefficient Of Thermal Conductivity

Abstract Increasing demand for usage of electronics intensely in narrow enclosures necessitates accurate thermal analyses to be performed. Conduction based FEM (Finite Element Method) is a common and practical way to examine the thermal behavior of an electronic system. First step to perform a numerical analysis for any system is to set up the correct analysis model. In this paper, a method for obtaining the coefficient of thermal conductivity and specific heat capacity of a PCB which has generally a complex composite layup structure composed of conductive layers, and dielectric layers. In the study, above mentioned properties are obtained performing a simple nondestructive experiment and a numerical analysis. In the method, a small portion of PCB is sandwiched from one side at certain pressure by jaws. A couple of linear temperature profiles are applied to the jaws successively. Unknown values are tuned in the analysis model until the results of FEM analysis and experiment match. The values for the coefficient of thermal conductivity and specific heat capacity which the experiment and numerical analysis results match can be said to be the actual values. From this point on, the PCB whose thermal properties are determined can be analyzed numerically for any desired geometry and boundary condition.

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