Research on the Pass Optimization Design of Sintered Shale Porous Brick

2014 ◽  
Vol 672-674 ◽  
pp. 1879-1884
Author(s):  
Jian Long Liu ◽  
Jie Nan Xie ◽  
Peng Liu ◽  
Mu Ye Huang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Optimization Design ◽  
Void Ratio ◽  
Thermal Conductivity Coefficient ◽  
Time Factors ◽  
Structure Design ◽  
3D Numerical Simulation ◽  
Equivalent Thermal Conductivity ◽  
Insulation Performance

The equivalent thermal conductivity coefficient of 10 kinds of sintered shale porous brick with different void number, void ratio, and arrangement (size: 240mm x 190mm x 90mm) are studied through 3D numerical simulation. An optimal structure design of the shale perforated brick design has been obtained. At the same time, factors such as void ratio, void number and arrangement of porous brick affected thermal insulation performance are systematically analyzed, which provides a reference to further improving the thermal insulation performance of insulation sintered shale porous brick model.

Analysis of the Sintered Porous Brick Wall Insulation Performance Using Different Ways Masonry

2015 ◽  
Vol 1092-1093 ◽  
pp. 550-554
Author(s):  
Jian Long Liu ◽  
Jie Nan Xie ◽  
Peng Liu ◽  
Mu Ye Huang
Keyword(s):  
Thermal Conductivity ◽  
Void Ratio ◽  
Thermal Conductivity Coefficient ◽  
Three Dimensional ◽  
Masonry Wall ◽  
Brick Wall ◽  
Equivalent Thermal Conductivity ◽  
Insulation Effect ◽  
Heat Transfers ◽  
Insulation Performance

Through the three-dimensional heat transfers numerical simulation of eight kinds with the different number of holes, void ratio and arrangement of sintered shale porous brick (size: 240mm×190mm×90mm), which simulate the sintered porous brick under two different laying way that is 240mm wall and 190mm wall of equivalent thermal conductivity. The result shows: the same kind of porous brick as 240mm wall and 190mm wall, when the equivalent thermal conductivity coefficient has phased difference that the wall insulation effect is obviously different. Through the analysis of two different methods of the masonry wall thermal insulation performance of the influence by different reasons, targeted to put forward some suggestions in order to improve calorific performance of the wall.

Influence of Air Entraining Agent on Performance of Inorganic Thermal Insulating Mortar

2011 ◽  
Vol 71-78 ◽  
pp. 490-493 ◽  
Author(s):  
Zhi Min He ◽  
Jun Zhe Liu ◽  
Tian Hong Wang
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Apparent Density ◽  
Thermal Conductivity Coefficient ◽  
Operating Performance ◽  
Drying Shrinkage ◽  
Test Results ◽  
Thermal Insulating ◽  
Excessive Consumption

This paper presents a laboratory study on the effect of air entraining agent on the performance of thermal insulating mortar with glazed hollow bead. The test results show that with the dosage of air entraining agent increases, the consistency of thermal insulating mortar increases, apparent density, thermal conductivity and drying shrinkage decline, However, the compressive strength greater losses owing to excessive consumption of air entraining agent; air entraining agent within a certain dosage can significantly improve the operating performance of thermal insulation mortar, increase its consistency and reduce its apparent density, thermal conductivity coefficient and drying shrinkage. Due to excessive addition of air entraining agent, the apparent density, thermal conductivity and compressive strength of thermal insulation mortar all increase. For a specific insulation mortar, there will exist the best mixing amount of air entraining agent.

Development of Out-Wall External Thermal Insulation System Based on Rock-Wool

2012 ◽  
Vol 174-177 ◽  
pp. 1589-1592
Author(s):  
Ming Gang Xu ◽  
Xu Wang ◽  
Zhuo Wei Ding
Keyword(s):  
Thermal Insulation ◽  
Thermal Conductivity Coefficient ◽  
Outer Wall ◽  
Sound Insulation ◽  
Insulation System ◽  
Stable Chemical ◽  
Insulation Systems ◽  
Saving Measure ◽  
Insulation Performance ◽  
Rock Wool

The outer-wall thermal insulation system has been wide used in civil engineering as an effective energy-saving measure. At present, the organic flammable thermal insulation materials such as EPS and XPS are used in outer-wall thermal insulation system in China, which leads to great fire damage probably. The rock-wool is described in detail on its merits such as good thermal insulation performance, good sound insulation performance, light weight, low thermal conductivity coefficient, incombustibility, innocuity and stable chemical capability. Two popular outer-wall external thermal insulation systems are introduced. The construction sequence of the outer-wall external thermal insulation system with rock-wool slabs, mortar and thin layer plastering technology is described.

Study on the Thermal Insulation Performance of PAN Pre-Oxidised Fibre Felts

2020 ◽  
Vol 28 (3(141)) ◽  
pp. 27-37
Author(s):  
Xiaoming Zhao ◽  
Yuanjun Liu ◽  
Tenglong Liang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Thermal Insulation ◽  
Silica Aerogel ◽  
Orthogonal Experiment ◽  
Excellent Thermal Stability ◽  
Coefficient Of Thermal Conductivity ◽  
Insulation Performance

In this paper, an orthogonal experiment of 3 factors and 3 levels was firstly designed to prepare PAN pre-oxidised fibre felts with good thermal insulation properties; the range method was used to analyse the result of the orthogonal experiment, and finally the tensile properties and thermal stability were tested. Finally, pre-oxidised fibre felt composites for the coating of silica aerogel were prepared using the coating process to compound silica aerogel on re-oxidised fibre felts. Firstly, the influence of the content of silica aerogel on the heat insulation performance of the coated composite materials was analysed, and then a test of the coefficient of thermal conductivity, an experiment on the back temperature, and characterisations of the tensile properties and thermal stability of the composite coating of pre-oxidised fibre felt composites of the coating of silica aerogel were carried out. Results showed that through analysis of the orthogonal experiment, we can state that the best preparation process of pre-oxidised fibre needled felts was as follows: needle number – 2, needle depth – 8 mm, and needle frequency – 140 times/min. The transverse tensile strength of PAN pre-oxidised fibre needled felts prepared by crossly webbing of PAN pre-oxidised fibres was superior to the longitudinal tensile strength; thermogravimetric analysis showed that the pre-oxidised fibre needled felts had excellent thermal stability. The coefficient of thermal conductivity of the aerogel coating of the composites firstly decreased and then increased with an increase in the content of aerogel. Coated composites had the lowest coefficient of thermal conductivity when the aerogel content was 4% wt. At temperatures of 100 °C, 150 °C and 200 °C, the heating rate of the transient-state back temperature and the steady-state average temperature were both the lowest when the aerogel content was 6% wt.

Fabrication and properties of carbon/carbon-carbon foam composites

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4452-4460
Author(s):  
Bin Wang ◽  
Bugao Xu ◽  
Hejun Li
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Bonding Strength ◽  
Carbon Foam ◽  
Shear Load ◽  
Foam Composite ◽  
Final Failure ◽  
Carbon Foams ◽  
Insulation Performance

This paper was focused on the development of a new composite for high thermal insulation applications with carbon/carbon (C/C) composites, carbon foams and an interlayer of phenolic-based carbon. The microstructure, mechanical properties, fracture mechanism and thermal insulation performance of the composite was investigated. The experiment results showed that the bonding strength of the C/C-carbon foam composite was 4.31 MPa, and that the fracture occurred and propagated near the interface of the carbon foam and the phenolic-based carbon interlayer due to the relatively weak bonding. The shear load-displacement curves were characterized by alternated linear slopes and serrated plateaus before a final failure. he experiment revealed that the thermal conductivity of the C/C-carbon foam composite was 1.55 W·m−1ċK−1 in 800℃, which was 95.8% lower than that of C/C composites, proving that the thermal insulation of the new foam composite was greatly enhanced by the carbon foam with its porous hollow microstructure.

scholarly journals Effect of density, phonon scattering and nanoporosity on the thermal conductivity of anisotropic cellulose nanocrystal foams

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Varvara Apostolopoulou-Kalkavoura ◽  
Pierre Munier ◽  
Lukasz Dlugozima ◽  
Veit-Lorenz Heuthe ◽  
Lennart Bergström
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Phonon Scattering ◽  
Cellulose Nanocrystal ◽  
Foam Density ◽  
Aqueous Dispersions ◽  
Gas Conduction ◽  
Insulation Performance ◽  
Ice Templating

AbstractAnisotropic cellulose nanocrystal (CNC) foams with densities between 25 and 130 kg m−3 (CNC25 –CNC130) were prepared by directional ice-templating of aqueous dispersions. Estimates of the solid and gas conduction contributions to the thermal conductivity of the foams using a parallel resistor model showed that the relatively small increase of the radial thermal conductivity with increasing foam density can be attributed to interfacial phonon scattering. The foam wall nanoporosity and, to a lesser extent, the orientation of the CNC particles and alignment of the columnar macropores, also influence the insulation performance of the foams. The insight on the importance of phonon scattering for the thermal insulation properties of nanocellulose foams provides useful guidelines for tailoring nanofibrillar foams for super-insulating applications.

Development of a Turbine Generator Stator 3D Thermal Model Taking into Account Gas Dynamics

Vestnik MEI ◽  
2021 ◽  
pp. 75-82
Author(s):  
Vitaliy V. Ryzhov ◽  
◽  
Pavel A. Dergachev ◽  
Ekaterina P. Kurbatova ◽  
Oleg N. Molokanov ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Gas Dynamics ◽  
Thermal Model ◽  
Thermal Conductivity Coefficient ◽  
Stator Winding ◽  
Insulation System ◽  
Turbine Generator ◽  
Stator Core ◽  
Equivalent Thermal Conductivity ◽  
Generator Stator

The construction of a thermal model of a fully air cooled turbine generator stator with taking into account gas dynamics is considered. The complete mathematical model includes various physical subsystems with multiphysical relationships. The study is based on accurate 3D models with the use of the modern and proven COMSOL Multiphysics software, in which the finite element method is used for calculation. The equivalent thermal conductivity of the gap between the winding bar copper conductors and stator iron is studied. The gap in question consists of the winding bar main insulation and a gap filled with additional semiconducting gaskets or similar materials. The above-mentioned physical parameter has a strong influence on the temperature distribution, because the main part of the heat releasing in the bar is transferred to the stator core through these elements. The optimal minimum equivalent thermal conductivity coefficient is analyzed and selected. A model of a turbine generator stator symmetric element together with a turbulent cooling air flow is developed and analyzed. The development of such integrated models will make it possible not only to simplify the design process, but also to analyze various insulation systems. For example, air-cooled turbine generators initially use the Global VPI insulation system; however, after replacing---for economic reasons---the stator winding, another insulation system is used, namely, the Resin Rich system. For correctly making a transition to another insulation system, integrated calculations, including thermal ones, should be carried out. In practice, after changing the insulation system, which may entail certain thermal limitations, it may be necessary to decrease the turbine generator rated power output for its further operation without overheating the stator winding, which can be obtained on the basis of simulation. In this regard, the equivalent thermal conductivity coefficient also plays an important role; its value can be preliminarily analyzed to select the necessary materials in terms of their thermal properties, and their filling factor to retain the turbine generator nominal parameters after its rewinding.

Study on Preparation and Properties of Cement-Based Foamed Lightweight Thermal Insulation Material

2011 ◽  
Vol 306-307 ◽  
pp. 994-997
Author(s):  
Cong Cong Jiang ◽  
Guo Zhong Li ◽  
Shui Zhang
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Fly Ash ◽  
Thermal Insulation ◽  
Thermal Conductivity Coefficient ◽  
Steel Slag ◽  
Activation Mechanism ◽  
Dry Density ◽  
Insulation Material ◽  
Thermal Insulation Material

A cement-based foamed lightweight thermal insulation material was prepared with cement, industrial waste (fly ash, steel slag) as the main raw materials, by using self-developed composite activator and foaming agent. The influence of foam content on dry density, compressive strength and thermal conductivity coefficient of material was studied, the activation mechanism of composite activator to fly ash and steel slag was discussed. Results showed that, the dry density and compressive strength of material decreased, and thermal conductivity coefficient decreased first and then increased with the increasing foam content.

Fabrication of Infrared Opacifiers Loaded Al2O3 Aerogel-SiO2 Fiber Mat Composites with High Thermal Resistance

2020 ◽  
Vol 19 (03) ◽  
pp. 1950021
Author(s):  
Shangyan Wen ◽  
Jiayi Zhu ◽  
Qiang Yin ◽  
Yutie Bi ◽  
Hongbo Ren ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Insulation ◽  
Sol Gel ◽  
Doping Content ◽  
Low Thermal Conductivity ◽  
Sic Particles ◽  
Sol Gel Process ◽  
High Thermal Resistance ◽  
Insulation Performance

The infrared opacifiers loaded Al2O3 aerogel-SiO2 fiber mat composites were fabricated by the sol–gel process. The effects of the content of the TiO2 and SiC particles on thermal insulation performance of the Al2O3 aerogel-SiO2 fiber mat composites were studied. The results showed that the optimum doping content of TiO2 and SiC for Al2O3 aerogel-SiO2 fiber mat composites were 10[Formula: see text]mol.% and 0.5[Formula: see text]mol.%, respectively. The optimum TiO2-Al2O3 aerogel-SiO2 fiber mat composite had the low thermal conductivity of 0.021[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 35∘C and 0.031[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 600∘C. Meanwhile, the SiC-Al2O3 aerogel-SiO2 fiber mat composite also had the low thermal conductivity of 0.022[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 35∘C and 0.025[Formula: see text]W/(m[Formula: see text][Formula: see text][Formula: see text]K) at 600∘C.

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