An Evaluation of Performance Characteristics of Short-Fiber Basalt Insulation at Cryogenic Temperatures

2020 ◽  
pp. 59-68
Author(s):  
M.A. Komkov ◽  
M.P. Timofeev ◽  
A.V. Larionova
Keyword(s):  
Thermal Insulation ◽  
Radiation Heat Transfer ◽  
Short Fiber ◽  
Insulation Material ◽  
Compression Tests ◽  
Basalt Fibers ◽  
Binding Agent ◽  
Evaluation Of Performance ◽  
Mineral Binding ◽  
Highly Porous

This work shows the potential of highly porous thermal insulation made of short basalt super-thin fibers chopped using liquid technology for insulating cryogenic piping. The effective heat conductivity coefficient, maximum-permissible porosity and insulation density were determined for short basalt fibers with a mean diameter of 1.88 mcm and a length of 1.0–1.5 mm, taking into account radiation heat transfer. The results of compression tests are presented for highly porous flat insulation samples made of short basalt fibers without binding agents and those reinforced with Al2O3. It is established that the thermal insulation material containing a binding agent has the strength, elasticity modulus and elastic compression deformation two times higher than samples without a mineral binding agent.

The Application of Closed-Cell Foaming Technology in Composite Thermal Insulation Material

2013 ◽  
Vol 357-360 ◽  
pp. 1286-1290 ◽  
Author(s):  
Chao Wang
Keyword(s):  
Thermal Insulation ◽  
Radiation Heat Transfer ◽  
Lightweight Aggregate ◽  
Insulation Material ◽  
Radiation Heat ◽  
Thermal Insulation Material ◽  
Hardening Mechanism ◽  
Closed Cell ◽  
Micro Holes ◽  
Foaming Technology

Composite thermal insulation material can be made from expanded and vitrified small balls and other inorganic insulation lightweight aggregate. According to the hydration, hardening mechanism of inorganic gel material and materials thermal insulation mechanism, we can eliminate the heat convection of gas inside the holes by using foaming technology, and micro holes can reduce radiation heat transfer between the pore walls so as to further improve the thermal insulation properties of solid materials.

Structure Designing and Property Investigation of Flexible Multilayer Thermal Insulation Materials

2011 ◽  
Vol 15 (3) ◽  
pp. 21-27 ◽  
Author(s):  
Jinjing Chen ◽  
Weidong Yu
Keyword(s):  
Heat Transfer ◽  
Thermal Insulation ◽  
Thermal Performance ◽  
Thermal Contact ◽  
Radiation Heat Transfer ◽  
Insulation Material ◽  
Insulation Materials ◽  
Compressive Loads ◽  
Multilayer Insulation ◽  
Gas Conduction

In this paper, a method of designing flexible multilayer insulation is analyzed and discussed, with focus on reducing the three basic modes of heat transfer (thermal radiation, solid spacer and residual gas conduction). The foundation for designing the new flexible thermal insulation material is provided. The insulation performances of different types (by choosing different reflection shields and spacers) of flexible multilayer insulation materials are obtained through measurements using a KES-F7 Thermal Labo II apparatus. The thermal performance of flexible multilayer insulation materials at different layers are also presented, and the best is about 20∼25 layers. To improve the thermal performance of multilayer insulation materials, treble spacers between double aluminized shields are applied. Aluminized shields with air, meshes, wool fibres, etc. are compared with each other. The aluminized shields with meshes fixed with down can reduce thermal contact, which reduces the radiation heat transfer more fully and can be more steady than the other spacers in the project applications. With the same layers and spacers, the thermal conductivity of crinkled aluminized shields is lower than that of the smooth aluminized shields. The effects of compressive loads on layer density and thermal performance are also investigated.

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.

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