scholarly journals Destruction of thermal insulation and effectiveness of the thermal energy transfer system

2019 ◽  
Vol 124 ◽  
pp. 01030
Author(s):  
E. R. Bazukova ◽  
T. O. Politova ◽  
E. R. Khaziakhmetova ◽  
A. A. Medyakov ◽  
I. Kolcunova

The work is devoted to improving the efficiency of the system of thermal energy transportation. The results of determining the thermophysical properties, such as the coefficient of thermal conductivity, water absorption, vapor permeability, the percentage of structural changes in the fibers during heating and exposure to vibration, basalt super thin fiber and other thermal insulation materials are presented. The results of thermal imaging testing control of basalt super-thin fiber mats are presented. The effect of the degree of thermal insulation aging on the increase in the heat flow density is shown.

2015 ◽  
Vol 10 (3) ◽  
pp. 155892501501000 ◽  
Author(s):  
Dunja Sajn Gorjanc ◽  
Matejka Bizjak

The comfort characteristics of fabrics (especially thermal insulation and permeability properties) are closely associated with the changes in their structural parameters. The reaction of a stretchable fabric, either after the finishing process or after a mechanical deformation, is higher than the reaction of conventional fabrics. The reaction after the finishing process is usually expressed in terms of density, thickness or mass increase, and in dimensional changes. The structural changes influence thermal insulation and water vapor permeability properties, which are the most important properties associated with the comfort of textiles. This paper focuses on the impact of the pre-finishing process on the comfort characteristics of pure cotton fabrics and of cotton fabrics with elastane in the weft direction in plain and twill weave. The results indicate that after the pre-finishing process (scouring/bleaching) for the analyzed fabrics, water vapor resistance and thermal resistance decrease. These decreases occur due to the structural changes inside the fabrics (warp yarn density and mass increase, whereas thickness decreases).


2020 ◽  
Vol 216 ◽  
pp. 01078
Author(s):  
Elvira Bazukova ◽  
Yuri Vankov

The work is devoted to solving the problem of increasing the operational reliability of industrial thermal insulation, taking into account the prediction of changes in its properties during operation. A series of experiments was carried out with samples of mineral wool insulation made of basalt fiber of different density. The dependence of thermal conductivity λ of basalt fiber insulation on density and temperature in the range from 50 to 350 °С is presented.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2443
Author(s):  
Andreea Hegyi ◽  
Cezar Bulacu ◽  
Henriette Szilagyi ◽  
Adrian-Victor Lăzărescu ◽  
Vasile Meiţă ◽  
...  

Currently, the need to ensure adequate quality of air inside the living space but also the thermal efficiency of buildings is pressing. This paper presents the capacity of sheep wool heat-insulating mattresses to simultaneously provide these needs, cumulatively analyzing efficiency indicators for thermal insulation and indicators of improving air quality. Thus, the values obtained for the coefficient of thermal conductivity, and its resistance to heat transfer, demonstrate the suitability of their use for thermal insulation. The results of the permeability to water vapor characteristics on the sorption/desorption of water, air, demonstrate the ability to control the humidity of the indoor air and the results on the reduction of the concentration of formaldehyde, demonstrating their contribution to the growth of the quality of the air, and to reduce the risk of disease in the population.


2019 ◽  
Vol 10 (2) ◽  
pp. 59-66
Author(s):  
E. A Biryuzova ◽  
A. S Glukhanov

Through pipelines of heat networks, due to their large length, a large amount of thermal energy is lost. Identification of technical solutions related to improving the energy efficiency of heating networks is an urgent task at present. The article is devoted to the consideration of options for laying pipelines of heat networks during design work. In the conducted studies, two main methods of underground laying of pipelines of heat networks with the choice of the most energy-efficient, with minimal losses of thermal energy are considered. Channel and channelless laying methods are investigated with the same design features and technological conditions of operation of pipelines of heat networks using the same thermal insulation material. For each option, the required thickness of the thermal insulation is determined by the normalized density of the heat flow, thermal calculations are performed to determine the heat loss and the value of the temperature fields generated around the operating pipelines of the heat networks. The obtained values of the thermal insulation thickness in the channel method of laying pipelines are 30-50 % lower than those in channelless laying. The heat loss values, according to the results of the heat calculation for the options under consideration, in the channel method of laying are reduced by 47-65 %. The temperature fields formed around the pipelines of thermal networks with channelless laying significantly exceed the natural value of the soil temperature at the depth of the pipeline. What has a great influence on the determination of the distance to adjacent pipelines and other utilities, laid underground, in the zone of the thermal network. A comparative analysis of the results obtained makes it possible to single out the choice of the method of laying the pipeline into a group of measures aimed at energy saving and increasing energy efficiency in heating systems.


2021 ◽  
Vol 887 ◽  
pp. 480-486
Author(s):  
T.N. Vachnina ◽  
I.V. Susoeva ◽  
A.A. Titunin ◽  
S.V. Tsybakin

Many plant wastes are not currently used in production, they are disposed of in landfills or incinerated. The aim of this study is to develop a composite thermal insulation material from unused spinning waste of flax and cotton fibers and soft wood waste. Samples of thermal insulation materials from plant waste were made by drying using the technology of production of soft wood fiber boards. For composite board defined physico-mechanical characteristics and thermal conductivity. The experiment was carried out according to a second-order plan, regression models of the dependences of the material indicators on the proportion of the binder additive, drying temperature and the proportion of wood waste additives were developed. The study showed that composites from unused spinning waste of plant fibers and soft wood waste have the necessary strength under static bending, the swelling in thickness after staying in water is much lower in comparison with the performance of boards from other plant fillers. The coefficient of thermal conductivity of the boards is comparable with the indicator for mineral wool boards.


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3354 ◽  
Author(s):  
Piselli ◽  
Pisello ◽  
Saffari ◽  
Gracia ◽  
Cotana ◽  
...  

Cool roof effectiveness in improving building thermal-energy performance is affected by different variables. In particular, roof insulation level and climate conditions are key parameters influencing cool roofs benefits and whole building energy performance. This work aims at assessing the role of cool roof in the optimum roof configuration, i.e., combination of solar reflectance capability and thermal insulation level, in terms of building energy performance in different climate conditions worldwide. To this aim, coupled dynamic thermal-energy simulation and optimization analysis is carried out. In detail, multi-dimensional optimization of combined building roof thermal insulation and solar reflectance is developed to minimize building annual energy consumption for heating–cooling. Results highlight how a high reflectance roof minimizes annual energy need for a small standard office building in the majority of considered climates. Moreover, building energy performance is more sensitive to roof solar reflectance than thermal insulation level, except for the coldest conditions. Therefore, for the selected building, the optimum roof typology presents high solar reflectance capability (0.8) and no/low insulation level (0.00–0.03 m), except for extremely hot or cold climate zones. Accordingly, this research shows how the classic approach of super-insulated buildings should be reframed for the office case toward truly environmentally friendly buildings.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4298
Author(s):  
David Wünsch ◽  
Verena Sulzgruber ◽  
Markus Haider ◽  
Heimo Walter

Renewables should become more continuously available, reliable and cost-efficient to manage the challenges caused by the energy transition. Thus, analytic and numerical investigations for the layout of a pilot plant of a concept called Fluidisation-Based Particle Thermal Energy Storage (FP-TES)—a highly flexible, short- to long-term fluidised bed regenerative heat storage utilising a pressure gradient for hot powder transport, and thus enabling minimal losses, high energy densities, compact construction and countercurrent heat exchange—are presented in this article. Such devices in decentralised set-up—being included in energy- and especially heat-intensive industries, storing latent or sensible heat or power-to-heat to minimise losses and compensate fluctuations—can help to achieve the above-stated goals. Part I of this article is focused on geometrical and fluidic design via numerical investigations utilising Computational Particle Fluid Dynamics (CPFD). In the process a controlled transient simulation method called co-simulation of FP-TES is developed forming the basis for test bench design and execution of further co-simulation. Within this process an advanced design of rotational symmetric hoppers with additional baffles in the heat exchanger (HEX) and internal pipes to stabilise the particle mass flow is developed. Moreover, a contribution bulk heat conductivity is presented to demonstrate low thermal losses and limited needs for thermal insulation by taking into account the thermal insulation of the outer layer of the hopper.


Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3075
Author(s):  
Štěpán Hýsek ◽  
Pavel Neuberger ◽  
Adam Sikora ◽  
Ondřej Schönfelder ◽  
Gianluca Ditommaso

This study provides a solution for the utilization of two waste materials, namely the residues of soft polyurethane foam from the production of mattresses and winter wheat husks. Thermal insulation panels with a nominal density of 50–150 kg/m3, bonded one-component moisture curing polyurethane adhesive, were developed, and the effect of the ratio between recycled polyurethane foam and winter wheat husk on internal bond strength, compressive stress at 10% strain, water uptake, coefficient of thermal conductivity, and volumetric heat capacity was observed. The developed composite materials make use of the very good thermal insulation properties of the two input waste materials, and the coefficient of thermal conductivity of the resulting boards achieves excellent values, namely 0.0418–0.0574 W/(m.K). The developed boards can be used as thermal insulation in the structures of environmentally friendly buildings.


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