Optimum position and distribution of insulation layers for exterior walls of a building conditioned by earth-air heat exchanger

Rosti, Behnam; Omidvar, Amir; Monghasemi, Nima

doi:10.1016/j.applthermaleng.2019.114362

Cited by 28 publications

(8 citation statements)

References 24 publications

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“…The insulation capacity is significantly enhanced via increasing the TIL thickness and decreasing the TIL thermal conductivity, which agrees with previous studies in cold region tunnels [10,45,46]. However, with thickening TIL and decreasing TIL thermal conductivity, the enhancement of the thermal insulation capacity remarkably decreases [25,47], but the TIL cost rapidly increases [43,44]. Therefore, how to balance the TIL insulation capacity and economy is necessary to be considered in the design of high-temperature tunnels.…”

Section: Discussionsupporting

confidence: 86%

Numerical Study on Thermal Damage Behavior and Heat Insulation Protection in a High-Temperature Tunnel

Kang

Tang

et al. 2021

Applied Sciences

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Deepening our understanding of temperature and stress evolution in high-temperature tunnels is indispensable for tunnel support and associated disaster prevention as the rock temperature is remarkably high in hot dry rock (HDR) utilization and similar tunnel engineering. In this paper, we established a two-dimensional thermal–mechanical coupling model through RFPA2D-thermal, by which the temperature and stress field of the surrounding rock in a high-temperature tunnel with and without thermal insulation layer (TIL) were studied, followed by the evolution of thermal cracks. The associated sensitivity analysis of the TIL and airflow factors were then carried out. We found that (1) the tunnel rock is unevenly cooled down by the cold airflow, which induces thermal stress and damages the rock element when it exceeds the tensile strength of the rock mass. Those damaged rock elements accumulate and coalesce into visible cracks in the tunnel rock as the ventilation time goes, reducing the tunnel stability. (2) TIL effectively reduces the heat exchange between the airflow and tunnel rock and weakens the cold shock by the airflow, delaying the crack initiation which provides efficient time to adopt engineering measures for tunnel supporting. (3) TIL parameters are of pivotal importance to the long-term cold shock by the airflow. Increasing the TIL thickness and reducing the TIL thermal conductivity both significantly enhance the thermal insulation effect. The results cover the gap in the study of cold shock in high-temperature tunnels, which is helpful in designs to prevent thermal damage in high-temperature tunnels.

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Section: Discussionsupporting

confidence: 86%

Numerical Study on Thermal Damage Behavior and Heat Insulation Protection in a High-Temperature Tunnel

Kang

Tang

et al. 2021

Applied Sciences

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“…Суммарную погрешность можно определить как 4 : В работе использовался метод математического планирования эксперимента, к позволил при проведении минимального количества опытов получить максим информацию по выходным параметрам, прочности и плотности [20,21,22,23,24,25].…”

Section: рисунок 2 -лабораторная установка пневматического смесителя ...unclassified

Mixing of heat-insulating mixtures in pneumatic mixer with spiral energy carrying tube

et al. 2023

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Introduction. Mixing of dry components in mixers is one of the most important stages of any technological process in the manufacture of a composite material. To date, various technologies use a wide variety of mixing equipment, which is characterized by different principles of mixing and design solutions. Of particular interest for the preparation of high-quality and homogeneous mixtures for heat-insulating purposes is a pneumatic mixer with a spiral energycarrying tube. The article presents the results of studies using the method of mathematical planning of the fullfactor ПФЭЦКРП24 experiment, which makes it possible to most adequately assess the ongoing processes while minimizing systematic errors.Materials and methods. In the work, ЦЕМ 0 42,5Н ГОСТ 31108–2020 Portland cement with a specific surface area of 308 m2 / kg, sand of the Volsky deposit were used as raw materials for testing. Expanded vermiculite obtained as a result of heat treatment of natural vermiculite at a temperature of about 700°C was used as a light filler.Results. Heat-insulating mixtures prepared in a pneumatic mixer with a spiral energy-carrying tube ensure the production of heat-insulating mortars with stable density values of 1420 kg/m3, having sufficient compressive strength of 3.3 MPa, and guarantee high heat-shielding properties in building structures.Conclusion. The developed design and the conducted studies made it possible to establish the high efficiency of the proposed mixer, which provides a uniform distribution of the particles to be mixed, high homogenization and the creation of conditions for accelerating the physicochemical interactions in the created mixture with subsequent mixing of the prepared mixture with water and the formation of the required internal structure of the created composites.

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“…Mahmoud and Ismaeel (2019) conducted simulation studies to examine the usage of three different roof design principles on the energy consumption in Egypt. Rosti et al (2019) calculated the optimum insulation configuration in buildings based on the theory of delay and decay factor. In the study, they made investigations for different multilayer wall configurations using the transient heat conduction equation.…”

Section: Introductionmentioning

confidence: 99%

Calculation of Insulation Thickness Depending on The Coolest and Hottest Climate Conditions for Different Flat Roof Types of Buildings

Kon

Caner

2023

Black Sea Journal of Engineering and Science

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In this study, optimum insulation thicknesses are calculated for three different flat-surfaces which are navigable terrace roof; stone-covered and soil-covered un-navigable flat roof types. The outdoor temperature, the value of January, which is the coldest month in winter, and the value of July, which is the hottest month in summer, and solar radiation, are considered together. Flat roof surfaces are considered to be stone-covered and soil-covered black painted and marble. Firstly, solar-air temperatures were determined for the winter and summer periods. Then, optimum insulation thickness calculations are made using life cycle total cost analysis. Extruded polystyrene (XPS) is accepted as the insulation material. Natural gas is used in winter and electricity in summer as an energy sources. The optimum insulation thicknesses have been calculated for five climate zones and three different roof types based on the TS 825. Then the results are compared. As a result, the optimum insulation thickness calculated considering the hottest and coldest months of the year was determined as 0.128 m in the 5th climate zone in roof 1 with the highest value, and as the lowest value with the 0.052 m in the 1st climate zone for roof 3.

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Optimum position and distribution of insulation layers for exterior walls of a building conditioned by earth-air heat exchanger

Cited by 28 publications

References 24 publications

Numerical Study on Thermal Damage Behavior and Heat Insulation Protection in a High-Temperature Tunnel

Numerical Study on Thermal Damage Behavior and Heat Insulation Protection in a High-Temperature Tunnel

Mixing of heat-insulating mixtures in pneumatic mixer with spiral energy carrying tube

Calculation of Insulation Thickness Depending on The Coolest and Hottest Climate Conditions for Different Flat Roof Types of Buildings

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