Experimental Investigation of Thermal Conductivity from Insulation Based on Rice Hulks: Guarded and Calibrated Hot Box Method

2021 ◽  
Vol 1046 ◽  
pp. 71-76
Author(s):  
Yokasta García Frómeta ◽  
Francisco Ramírez Rivera ◽  
Víctor González Holguín ◽  
Jesús Cuadrado
Keyword(s):  
Thermal Conductivity ◽  
Energy Efficiency ◽  
Thermal Insulation ◽  
Agricultural Residues ◽  
Insulation Material ◽  
Construction Sector ◽  
Economic Activities ◽  
Standard Process ◽  
Box Method ◽  
Passive Techniques

In developing countries, large quantities of agricultural residues associated with harvests are generated, given that agriculture is one of the most important economic activities. The valorization of these residues for the construction sector could contribute to the improvement of energy efficiency in buildings. Through passive techniques, the construction of insulating thermal-acoustics panels, blocks, and aggregate for reinforced concrete can improve the energy efficiency. In this study, an experiment was performed to measure thermal conductivity of the Agricultural-Thermal Insulation Panel (ATIP) based on rice hulks. These Agricultural-Thermal Insulation Panels were elaborated follow a standard process to compaction of the rice hulks to be employed as insulation material with a panel dimension of 200x200x34.5(mm3). A “Hot Box” configuration was used to obtain the thermal conductivity of the panels, using different temperature gradients between hot and cold chambers.

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.

scholarly journals THE INFLUENCE OF THE METHOD OF LAYING PIPELINES ON THE ENERGY EFFICIENCY OF THE HEATING NETWORK

2019 ◽  
Vol 10 (2) ◽  
pp. 59-66
Author(s):  
E. A Biryuzova ◽  
A. S Glukhanov
Keyword(s):  
Energy Efficiency ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Thermal Energy ◽  
Great Influence ◽  
Temperature Fields ◽  
Insulation Material ◽  
Design Work ◽  
Heat Networks ◽  
Insulation Thickness

Through pipelines of heat networks, due to their large length, a large amount of thermal energy is lost. Identification of technical solutions related to improving the energy efficiency of heating networks is an urgent task at present. The article is devoted to the consideration of options for laying pipelines of heat networks during design work. In the conducted studies, two main methods of underground laying of pipelines of heat networks with the choice of the most energy-efficient, with minimal losses of thermal energy are considered. Channel and channelless laying methods are investigated with the same design features and technological conditions of operation of pipelines of heat networks using the same thermal insulation material. For each option, the required thickness of the thermal insulation is determined by the normalized density of the heat flow, thermal calculations are performed to determine the heat loss and the value of the temperature fields generated around the operating pipelines of the heat networks. The obtained values of the thermal insulation thickness in the channel method of laying pipelines are 30-50 % lower than those in channelless laying. The heat loss values, according to the results of the heat calculation for the options under consideration, in the channel method of laying are reduced by 47-65 %. The temperature fields formed around the pipelines of thermal networks with channelless laying significantly exceed the natural value of the soil temperature at the depth of the pipeline. What has a great influence on the determination of the distance to adjacent pipelines and other utilities, laid underground, in the zone of the thermal network. A comparative analysis of the results obtained makes it possible to single out the choice of the method of laying the pipeline into a group of measures aimed at energy saving and increasing energy efficiency in heating systems.

Unused Plant Waste and Thermal Insulation Composition Boards on their Basis

2021 ◽  
Vol 887 ◽  
pp. 480-486
Author(s):  
T.N. Vachnina ◽  
I.V. Susoeva ◽  
A.A. Titunin ◽  
S.V. Tsybakin
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Wood Fiber ◽  
Mineral Wool ◽  
Wood Waste ◽  
Insulation Material ◽  
Plant Fibers ◽  
Coefficient Of Thermal Conductivity ◽  
Plant Waste ◽  
Technology Of Production

Many plant wastes are not currently used in production, they are disposed of in landfills or incinerated. The aim of this study is to develop a composite thermal insulation material from unused spinning waste of flax and cotton fibers and soft wood waste. Samples of thermal insulation materials from plant waste were made by drying using the technology of production of soft wood fiber boards. For composite board defined physico-mechanical characteristics and thermal conductivity. The experiment was carried out according to a second-order plan, regression models of the dependences of the material indicators on the proportion of the binder additive, drying temperature and the proportion of wood waste additives were developed. The study showed that composites from unused spinning waste of plant fibers and soft wood waste have the necessary strength under static bending, the swelling in thickness after staying in water is much lower in comparison with the performance of boards from other plant fillers. The coefficient of thermal conductivity of the boards is comparable with the indicator for mineral wool boards.

scholarly journals Technical Performance Overview of Bio-Based Insulation Materials Compared to Expanded Polystyrene

Buildings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 81
Author(s):  
Cassandra Lafond ◽  
Pierre Blanchet
Keyword(s):  
Thermal Conductivity ◽  
Energy Efficiency ◽  
Natural Fibers ◽  
Expanded Polystyrene ◽  
Embodied Energy ◽  
Lower Amount ◽  
Vapor Permeability ◽  
Insulation Material ◽  
Insulation Materials ◽  
Technical Performance

The energy efficiency of buildings is well documented. However, to improve standards of energy efficiency, the embodied energy of materials included in the envelope is also increasing. Natural fibers like wood and hemp are used to make low environmental impact insulation products. Technical characterizations of five bio-based materials are described and compared to a common, traditional, synthetic-based insulation material, i.e., expanded polystyrene. The study tests the thermal conductivity and the vapor transmission performance, as well as the combustibility of the material. Achieving densities below 60 kg/m3, wood and hemp batt insulation products show thermal conductivity in the same range as expanded polystyrene (0.036 kW/mK). The vapor permeability depends on the geometry of the internal structure of the material. With long fibers are intertwined with interstices, vapor can diffuse and flow through the natural insulation up to three times more than with cellular synthetic (polymer) -based insulation. Having a short ignition times, natural insulation materials are highly combustible. On the other hand, they release a significantly lower amount of smoke and heat during combustion, making them safer than the expanded polystyrene. The behavior of a bio-based building envelopes needs to be assessed to understand the hygrothermal characteristics of these nontraditional materials which are currently being used in building systems.

Durability Research of Thermal Insulation Glazed Hollow Bead Concrete

2013 ◽  
Vol 639-640 ◽  
pp. 350-353 ◽  
Author(s):  
Xiao Hong Zheng ◽  
Zhu Li ◽  
Yuan Zhen Liu ◽  
Shang Song Qin
Keyword(s):  
Experimental Study ◽  
Energy Efficiency ◽  
Theoretical Analysis ◽  
Thermal Insulation ◽  
Raw Materials ◽  
Building Energy ◽  
Building Energy Efficiency ◽  
Insulation Material ◽  
Mixing Proportion ◽  
Good Workability

The durability of thermal insulation glazed hollow bead concrete, which is a kind of structure self-thermal insulation material produced in the background of building energy efficiency, has been systematically researched in order to make it with a good workability. Theoretical analysis and experimental study have been made from the raw materials and construction mixing proportion in the basis of the analysis to the influencing factors of its durability so as to can improve its durability.

The Development and Application of Non-Shrinking Composite Silicate Insulation Material

2013 ◽  
Vol 772 ◽  
pp. 178-181
Author(s):  
Yong Liang Zhan ◽  
Hai Yang Chen ◽  
Xing Hua Hou ◽  
Fei He
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Production Process ◽  
Thermal Insulation ◽  
Raw Materials ◽  
Drying Shrinkage ◽  
Structural Member ◽  
Insulation Material ◽  
Technical Performance

Non-shrinking composite silicate insulation material has advantages of low drying shrinkage, density, thermal conductivity and good thermal insulation which withstands high temperature and militates in favor of specially shaped structural member construction, etc. This article describes raw materials and the production process of the above material, discusses thermal insulation characteristics, technical performance and the features of use and particularizes the application effect in the project.

Effect of Operating Temperatures on Thermal Conductivity of Polystyrene Insulation Material: Impact on Envelope-Induced Cooling Load

2014 ◽  
Vol 564 ◽  
pp. 315-320 ◽  
Author(s):  
Maatouk Khoukhi ◽  
Mahmoud Tahat
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Energy Performance ◽  
Building Envelope ◽  
Insulation Material ◽  
Cooling Load ◽  
Thermal Insulation Material ◽  
Insulation Materials ◽  
Energy Performance Of Buildings ◽  
The Impact

The impact of the thermal conductivity (k-value) change of polystyrene insulation material in building envelope due to changes in temperature on the thermal and energy performance of a typical residential building under hot climate is investigated. Indeed, the thermal and energy performance of buildings depends on the thermal characteristics of the building envelope, and particularly on the thermal resistance of the insulation material used. The thermal insulation material which is determined by its thermal conductivity, which describes the ability of heat to flow cross the material in presence of a gradient of temperature, is the main key to assess the performance of the thermal insulation material. When performing the energy analysis or calculating the cooling load for buildings, we use published values of thermal conductivity of insulation materials, which are normally evaluated at 24°C according to the ASTM standards. In reality, thermal insulation in building is exposed to significant and continuous temperature variations, due essentially to the change of outdoor air temperature and solar radiation. Many types of insulation materials are produced and used in Oman, but not enough information is available to evaluate their performance under the prevailing climatic condition. The main objective of this study is to investigate the relationship between the temperature and thermal conductivity of various densities of polystyrene, which is widely used as building insulation material in Oman. Moreover, the impact of thermal conductivity variation with temperature on the envelope-induced cooling load for a simple building model is discussed. This work will serve as a platform to investigate the effect of the operating temperature on thermal conductivity of other building material insulations, and leads to more accurate assessment of the thermal and energy performance of buildings in Oman.

A Novel Building Thermal Insulation Material: Expanded Perlite Modified by Aerogel

2011 ◽  
Vol 250-253 ◽  
pp. 507-512
Author(s):  
Zi Sheng Wang ◽  
Hao Chi Tu ◽  
Jin Xiu Gao ◽  
Guo Dong Qian ◽  
Xian Ping Fan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Property ◽  
Thermal Insulation ◽  
Production Cost ◽  
Building Materials ◽  
Low Cost ◽  
Insulation Material ◽  
Expanded Perlite ◽  
Thermal Insulation Material ◽  
Supercritical Fluid Drying

Aerogel is regarded as one kind of super thermal insulation materials which could be large-scalely used as building materials. However, the aerogel’s production cost and poor mechanical property limit the its applications. In this paper, we put forward a new low cost way to produce a novel building thermal insulation material: synthesized the aerogel within the expanded perlite’s pores, and using sodium silicate as precursor without adopting supercritical fluid drying and surface modification. The thermal conductivity of expanded perlite was successfully decreased after modified by aerogel.

scholarly journals Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

2014 ◽  
Vol 14 (4) ◽  
pp. 259-269 ◽  
Author(s):  
Mikelis Kirpluks ◽  
Ugis Cabulis ◽  
Viesturs Zeltins ◽  
Laura Stiebra ◽  
Andris Avots
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Flame Retardants ◽  
Health Hazard ◽  
Expandable Graphite ◽  
Main Concern ◽  
Insulation Material ◽  
Pu Foam ◽  
Fibre Products ◽  
Pu Foams

Abstract One of the biggest disadvantages of rigid polyurethane (PU) foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ), which at 18-28 mW/(m•K) is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR) are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG) into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K). This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP) as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.

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