The Application of Thermal Insulation Glazed Hollow Bead Concrete in Tunnel Cooling Structure

2012 ◽  
Vol 226-228 ◽  
pp. 1699-1703 ◽  
Author(s):  
Ke Jie Li ◽  
Zhu Li ◽  
Xiu Hua Guo ◽  
Yuan Zhen Liu
Keyword(s):  
Thermal Insulation ◽  
Effect Of Temperature ◽  
Insulation Material ◽  
Tunnel Wall ◽  
Mixture Ratio ◽  
Deep Mine ◽  
Mining Depth ◽  
Exhaust Heat ◽  
Mine Roadway ◽  
Coefficient Of Heat Conductivity

With the mining depth increasing, the effect of temperature on coal mine is outstanding with each passing day. In order to enhance the tunnel insulating layer heat insulation effect, thermal insulation glazed hollow bead concrete will be used in tunnel wall thermal insulation layer, the characteristics of thermal insulation glazed hollow bead concrete will be discussed and the appropriate mixture ratio and coefficient of heat conductivity will also be determined, as well as in the basis of reasonable theoretical analysis and derivation, prediction of the thermal insulation material of surrounding rock after exhaust heat will drop significantly, and it is proved that the thermal insulation glazed hollow bead concrete used in deep mine roadway can produce the benefit and have broad prospects.

Preparation and Properties of a Novel Nonflammable Thermal Insulation Material

2012 ◽  
Vol 450-451 ◽  
pp. 1504-1512 ◽  
Author(s):  
Dan Shi ◽  
Ling Shi ◽  
Jun Ying Zhang ◽  
Jue Cheng
Keyword(s):  
Compressive Strength ◽  
Thermal Insulation ◽  
Heat Conductivity ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Insulation Material ◽  
Material Density ◽  
Thermal Insulation Material ◽  
Blowing Agent ◽  
Coefficient Of Heat Conductivity

A novel nonflammable thermal insulation material for buildings was prepared by foaming sodium silicate solution with blowing agent. The material density is 274 kg/m3,with the compressive strength up to 2.0MPa and the coefficient of heat conductivity low to 0.08 W/ m•K.

scholarly journals Fungal Based Biopolymer Composites for Construction Materials

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2906
Author(s):  
Iuliana Răut ◽  
Mariana Călin ◽  
Zina Vuluga ◽  
Florin Oancea ◽  
Jenica Paceagiu ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Renewable Resources ◽  
Heat Exposure ◽  
Construction Materials ◽  
Bacterial Spores ◽  
Fungal Mycelium ◽  
Insulation Material ◽  
Construction Sector ◽  
Low Costs ◽  
Microscopy Images

Environmental contamination, extensive exploitation of fuel sources and accessibility of natural renewable resources represent the premises for the development of composite biomaterials. These materials have controlled properties, being obtained through processes operated in mild conditions with low costs, and contributing to the valorization of byproducts from agriculture and industry fields. A novel board composite including lignocelullosic substrate as wheat straws, fungal mycelium and polypropylene embedded with bacterial spores was developed and investigated in the present study. The bacterial spores embedded in polymer were found to be viable even after heat exposure, helping to increase the compatibility of polymer with hydrophilic microorganisms. Fungal based biopolymer composite was obtained after cultivation of Ganoderma lucidum macromycetes on a mixture including wheat straws and polypropylene embedded with spores from Bacillus amyloliquefaciens. Scanning electron microscopy (SEM) and light microscopy images showed the fungal mycelium covering the substrates with a dense network of filaments. The resulted biomaterial is safe, inert, renewable, natural, biodegradable and it can be molded in the desired shape. The fungal biocomposite presented similar compressive strength and improved thermal insulation capacity compared to polystyrene with high potential to be used as thermal insulation material for applications in construction sector.

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

2021 ◽  
pp. 0021955X2110626
Author(s):  
Tae Seok Kim ◽  
Yeongbeom Lee ◽  
Chul Hyun Hwang ◽  
Kwang Ho Song ◽  
Woo Nyon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Cell Size ◽  
Thermal Insulation ◽  
Coefficient Of Thermal Expansion ◽  
Lower Surface ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Pu Foams

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.

Considerations in Design of Centralizers for Pipe-in-Pipe Systems

2018 ◽  
Author(s):  
Soheil Manouchehri
Keyword(s):  
Heat Loss ◽  
Thermal Insulation ◽  
Insulation Material ◽  
Loading History ◽  
Pipe Systems ◽  
Main Components ◽  
Outer Pipe

For un-bonded (sliding) Pipe-In-Pipe (PIP) systems, one of the main components is the centralizers (also called spacers). The main functions of the centralizers are to centralize the inner pipe inside the outer pipe, to transfer the loads between inner pipe and outer pipe and to safeguard the insulation material in the annulus from excessive compression during fabrication, installation and operation. Centralizers must also have good thermal insulation properties so that the heat loss is minimized. Different designs are now available for centralizers but the majority are based on two half shells which are bolted together. During fabrication, installation and operation, centralizers subject to different loads under which they are required to continue functioning properly. This paper provides an overview of centralizer design aspects and then focuses on the loading history during installation using reeling method. The main contributing parameters to centralizer loading during reeled installation technique are discussed and conclusions are drawn. It is believed that this will enable Pipeline Engineers to select the most appropriate material and design for centralizers.

Preparation and Properties of Phase Change Thermal Insulation Materials

2018 ◽  
Vol 281 ◽  
pp. 131-136
Author(s):  
Shi Chao Zhang ◽  
Wei Wu ◽  
Yu Feng Chen ◽  
Liu Shi Tao ◽  
Kai Fang ◽  
...  
Keyword(s):  
Phase Change ◽  
Thermal Insulation ◽  
Calcium Silicate ◽  
Phase Change Materials ◽  
Performance Test ◽  
Thermal Protection ◽  
Insulation Material ◽  
Insulation Materials ◽  
Short Time ◽  
Change Material

With the increase of the speed of vehicle, the thermal protection system of its powerplant requires higher insulation materials. Phase change materials can absorb large amounts of heat in short time. So the introduction of phase change materials in thermal insulation materials can achieve efficient insulation in a limited space for a short time. In this paper, a new phase change thermal insulation material was prepared by pressure molding with microporous calcium silicate as matrix and Li2CO3 as phase change material. The morphology stability, exudation and heat insulation of the materials were tested. The results show that the porous structure of microporous calcium silicate has a good encapsulation when the phase transition of Li2CO3 is changed into liquid. And the material has no leakage during use. The thermal performance test also shows that the insulation performance of the material has obvious advantages in the short term application.

Influences of Emulsion on Water Resistance of Vitrified Micro Bubbles Thermal Insulation Material

2013 ◽  
Vol 662 ◽  
pp. 433-436
Author(s):  
Jiang Zhu ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Polyvinyl Alcohol ◽  
Stearic Acid ◽  
Thermal Insulation ◽  
Water Resistance ◽  
Insulation Material ◽  
Molding Process ◽  
Thermal Insulation Material ◽  
Improve Water Resistance ◽  
Softening Coefficient

Vitrified micro bubbles thermal insulation material was made of vitrified micro bubbles, cement, fly ash, gypsum and sodium silicate, by molding process. VAE emulsion and stearic acid-polyvinyl alcohol emulsion were added to improve water resistance of the material. Mixed with 10% VAE emulsion and 5% stearic acid-polyvinyl alcohol emulsion, properties of the material are followed as: flexural strength 0.64MPa, compressive strength 1.35MPa, softening coefficient 0.71 and 2h volumetric water absorption 6.9%.

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