An active thermal insulation system using semitransparent porous media for protection against intense irradiation

1989 ◽  
Author(s):  
S. MARUYAMA ◽  
R. VISKANTA ◽  
T. AIHARA
Keyword(s):  
Porous Media ◽  
Thermal Insulation ◽  
Insulation System ◽  
Active Thermal Insulation

scholarly journals Design and Verification of a Deep Rock Corer with Retaining the In Situ Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhiqiang He ◽  
Heping Xie ◽  
Mingzhong Gao ◽  
Ling Chen ◽  
Bo Yu ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Heat Dissipation ◽  
Electric Heating ◽  
Transfer Model ◽  
Hollow Glass Microsphere ◽  
Insulation Material ◽  
Insulation System ◽  
Deep Rock ◽  
Active Thermal Insulation

Deep rock is always under high-temperature conditions. However, traditional coring methods generally have no thermal insulation design, which introduces large deviations in the guidance required for resource mining. Thus, a thermal insulation design that utilizes active and passive thermal insulation was proposed for deep rock corers. The rationale behind the active thermal insulation scheme was to maintain the in situ core temperature through electric heating that was controlled by using a proportional-integral-derivative (PID) chip. Graphene heating material could be used as a heating material for active thermal insulation through testing. In regard to the passive thermal insulation scheme, we conducted insulation and microscopic and insulation effectiveness tests for hollow glass microsphere (HGM) composites and SiO2 aerogels. Results showed that the #1 HGM composite (C1) had an excellent thermal insulation performance (3 mm thick C1 can insulate to 82.6°C), high reflectivity (90.02%), and wide applicability. Therefore, C1 could be used as a passive insulation material in deep rock corers. Moreover, a heat transfer model that considered multiple heat dissipation surfaces was established, which can provide theoretical guidance for engineering applications. Finally, a verification test of the integrated active and passive thermal insulation system (graphene heating material and C1) was carried out. Results showed that the insulating effect could be increased by 13.3%; thus, the feasibility of the integrated thermal insulation system was verified. The abovementioned design scheme and test results provide research basis and guidance for the development of thermally insulated deep rock coring equipment.

scholarly journals Experimental and Numerical Study on the Heat Transfer Characteristics of a Newly-Developed Solar Active Thermal Insulation System

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 123
Author(s):  
Peter Steininger ◽  
Matthias Gaderer ◽  
Oliver Steffens ◽  
Belal Dawoud
Keyword(s):  
Solar Energy ◽  
Thermal Insulation ◽  
Numerical Study ◽  
Incidence Angle ◽  
Incident Radiation ◽  
Short Wave ◽  
Wave Radiation ◽  
Insulation System ◽  
Active Thermal Insulation ◽  
Irradiation Angle

A newly-developed solar active thermal insulation system (SATIS) is introduced with the main objective to accomplish a highly-dependent total solar transmittance on the irradiation angle. SATIS is also designed to obtain the maximum transmittance at a prescribed design irradiation angle and to reduce it remarkably at higher irradiation angles. A purely mineral thermal insulation plaster with micro hollow glass spheres is applied to manufacture the investigated SATIS prototype. Light-conducting elements (LCEs) have been introduced into SATIS and suitable closing elements have been applied. The SATIS prototype has been investigated both experimentally and numerically. It turned out that the contributions of conduction, radiation and convection to the effective thermal conductivity of SATIS, without the closing elements (49 mWmK), amount to 86.2%, 13.2% and 0.6%, respectively. The angle-dependent short-wave radiation exchange within the LCE has been investigated via ray tracing. At the incidence angle of 19% (design angle), 27% of the radiation within the LCE is absorbed by the absorber plate, resulting in measured and computed total solar energy transmittances of 11.2%/11.7%, respectively. For a typical summer irradiation angle of 60%, 98% of the incident radiation is absorbed by the surfaces at the entrance of the LCE. The corresponding total solar energy transmittance amounts to 2.9%.

scholarly journals The Analysis of Small Investors’ Demands on a Thermal Insulation System for a Family House: A Case Study

2021 ◽  
Vol 13 (5) ◽  
pp. 2491
Author(s):  
Alena Tažiková ◽  
Zuzana Struková ◽  
Mária Kozlovská
Keyword(s):  
Decision Making ◽  
Thermal Insulation ◽  
Construction Cost ◽  
Environmental Cost ◽  
Multi Criteria Decision Making ◽  
Insulation System ◽  
Insulation Systems ◽  
Small Investors ◽  
The Cost ◽  
Family House

This study deals with small investors’ demands on thermal insulation systems when choosing the most suitable solution for a family house. By 2050, seventy percent of current buildings, including residential buildings, are still expected to be in operation. To reach carbon neutrality, it is necessary to reduce operational energy consumption and thus reduce the related cost of building operations and the cost of the life cycle of buildings. One solution is to adapt envelopes of buildings by proper insulation solutions. To choose an optimal thermal insulation system that will reduce energy consumption of building, it is necessary to consider the environmental cost of insulation materials in addition to the construction cost of the materials. The environmental cost of a material depends on the carbon footprint from the initial origin of the material. This study presents the results of a multi-criteria decision-making analysis, where five different contractors set the evaluation criteria for selection of the optimal thermal insulation system. In their decision-making, they involved the requirements of small investors. The most common requirements were selected: the construction cost, the construction time (represented by the total man-hours), the thermal conductivity coefficient, the diffusion resistance factor, and the reaction to fire. The confidences of the criteria were then determined with the help of the pairwise comparison method. This was followed by multi-criteria decision-making using the method of index coefficients, also known as the method of basic variant. The multi-criteria decision-making included thermal insulation systems based on polystyrene, mineral wool, thermal insulation plaster, and aerogels’ nanotechnology. As a result, it was concluded that, currently, in Slovakia, small investors emphasize the cost of material and the coefficient of thermal conductivity and they do not care as much about the carbon footprint of the material manufacturing, the importance of which is mentioned in this study.

Comparative study on thermodynamic characteristics of composite thermal insulation systems with liquid methane, oxygen, and hydrogen

2021 ◽  
pp. 1-18
Author(s):  
Xiafan Xu ◽  
Jianpeng Zheng ◽  
Hao Xu ◽  
Liubiao Chen ◽  
Junjie Wang
Keyword(s):  
Comparative Study ◽  
Thermal Insulation ◽  
Thermodynamic Characteristics ◽  
Calculation Model ◽  
System Structure ◽  
Insulation System ◽  
Optimal Position ◽  
Heat Leakage ◽  
Cryogenic Liquids ◽  
Liquid Methane

Abstract Composite passive insulation technology has been proved to be an effective method to reduce heat leakage into the cryogenic storage tank. However, the current related research mainly focused on liquid hydrogen (LH2). The thermophysical properties of different cryogenic liquids and the thermal insulation materials at different temperatures are significantly different, so whether the results related to LH2 are applicable to other cryogenic liquids remains to be further determined. In fact, the insulation technology of LH2 itself also needs further study. In this paper, a thermodynamic calculation model of a composite insulation system including hollow glass microspheres (HGMs), multilayer insulation (MLI), and self-evaporating vapor cold shield (VCS) has been established. The accuracy of the calculation model was verified by the experimental results, and a comparative study on thermodynamic characteristics of the composite thermal insulation system with liquid methane, liquid oxygen (LO2), and LH2 was carried out. The results show that the heat leakage reduction of the proposed system for liquid methane, LO2 and LH2 is 25.6%, 29.7% and 64.9% respectively compared to the traditional SOFI+MLI system (1*10−3 Pa). The type of liquid and the insulation system structure has a relatively large influence on the VCS optimal position. While for a specific insulation system structure, the insulation material thickness, storage pressure, and hot boundary temperature have a weak influence on the VCS optimal position.

Study on Spread of Fire Overflow on Building Facades with Insulation Materials

2013 ◽  
Vol 405-408 ◽  
pp. 2438-2442
Author(s):  
Yan Feng Li ◽  
Cong Cong Xu ◽  
Xue Fei Xing ◽  
Jin Zhang ◽  
Cheng Hu
Keyword(s):  
Numerical Simulation ◽  
Thermal Insulation ◽  
Maximum Temperature ◽  
Computational Results ◽  
Exterior Wall ◽  
Insulation Layer ◽  
Insulation System ◽  
High Rise ◽  
Building Facades ◽  
Fire Barrier

Fire overflow on exterior wall with thermal insulation system has been studied by numerical simulation. The spread laws of fire overflow are analyzed through the temperature distribution near the window. The computational results are compared with those of test in the Exterior Insulation Fire Barrier Technical Guidelines (EIFBTG). It has been found that the calculated maximum temperature points is closed to the test on the first floor, the first ceiling, and the points near the above two windows. However, there are differences between two kinds of results above two floors and ceilings, and the points near the first window. It has also shown that when the HHR is 7.5KW, the scope of damage of exterior thermal insulation layer is about 15 square meters near the window. The research would provide reference for fire protection design of exterior wall thermal insulation in the high-rise buildings.

Simulation and Measurement of Hygrothermal Behaviour of Newly Developed Plasters

2016 ◽  
Vol 824 ◽  
pp. 598-605
Author(s):  
Jitka Hroudova ◽  
Martin Sedlmajer ◽  
Vitezslav Novak ◽  
Jiri Zach
Keyword(s):  
Thermal Insulation ◽  
Lightweight Aggregate ◽  
Energy Performance ◽  
Existing Buildings ◽  
Insulation System ◽  
Architectural Features ◽  
Harmful Emissions ◽  
Heat And Moisture Transport ◽  
The Cost ◽  
Heat And Moisture

Recently, there has been increased interest in the rehabilitation of existing buildings especially in order to improve their energy performance. Thermal insulation brings not only savings in the cost of heating or cooling but also contributes to the reduction of harmful emissions such as carbon dioxide, sulphur dioxide or nitrogen dioxide. However, the thermal insulation of historical buildings or buildings listed as cultural heritage brings some problems due to architectural features. It is therefore necessary to choose an alternative whether it is the use of an internal thermal insulation system or to repair and rehabilitate the existing plaster with materials compatible with the original ones. The newly developed thermal insulation plasters based on silicate and using lightweight aggregate and natural fibres are optimum materials for the thermal insulation of both existing and newly constructed buildings. The paper describes the results of research focused on the examination of the behaviour of thermal insulation plaster mainly in terms of heat and moisture transport. Using a computational programme, this behaviour was simulated for a chosen detail of a real building in the vicinity of a window jamb.

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