Evaluation of Structure Influence on Thermal Conductivity of Thermal Insulating Materials from Renewable Resources

1970 ◽  
Vol 17 (2) ◽  
pp. 208-212 ◽  
Author(s):  
Jolanta VĖJELIENĖ ◽  
Albinas GAILIUS ◽  
Sigitas VĖJELIS ◽  
Saulius VAITKUS ◽  
Giedrius BALČIŪNAS

The development of new thermal insulation materials needs to evaluate properties and structure of raw material, technological factors that make influence on the thermal conductivity of material. One of the most promising raw materials for production of insulation material is straw. The use of natural fibres in insulation is closely linked to the ecological building sector, where selection of materials is based on factors including recyclable, renewable raw materials and low resource production techniques In current work results of research on structure and thermal conductivity of renewable resources for production thermal insulating materials are presented. Due to the high abundance of renewable resources and a good its structure as raw material for thermal insulation materials barley straw, reeds, cattails and bent grass stalks are used. Macro- and micro structure analysis of these substances is performed. Straw bales of these materials are used for determining thermal conductivity. It was found that the macrostructure has the greatest effect on thermal conductivity of materials. Thermal conductivity of material is determined by the formation of a bale due to the large amount of pores among the stalks of the plant, inside the stalk and inside the stalk wall.http://dx.doi.org/10.5755/j01.ms.17.2.494

2014 ◽  
Vol 604 ◽  
pp. 285-288 ◽  
Author(s):  
Saulius Vaitkus ◽  
Rūta Karpavičiūtė ◽  
Sigitas Vėjelis ◽  
Lina Lekūnaitė

Natural fibres from flax and hemp are used as raw materials for efficient thermal insulation. In current work, tests were carried out using chopped and combed long flax fibres as well as chopped and combed long hemp fibres. Investigations have shown that thermal conductivity of natural fibres depends on their preparation method (combing, chopping) and materials density.


2011 ◽  
Vol 335-336 ◽  
pp. 1412-1417 ◽  
Author(s):  
Jiri Zach ◽  
Jitka Peterková ◽  
Vít Petranek ◽  
Jana Kosíková ◽  
Azra Korjenic

Production of building materials is mostly energy consuming. In the sphere of insulation materials we mostly see rock wool based materials or foam-plastic materials whose production process is demanding from material aspect and raw materials aspect as well. At present the demand for thermal insulation materials has been growing globally. The thermal insulation materials form integral part of all constructions in civil engineering. The materials mainly fulfill the thermal insulating functions and also the sound-insulating one. The majority of thermal insulation materials are able to fulfill both of the functions simultaneously. The paper describes questions of thermal insulation materials development with good sound properties based on natural fibres that represent a quickly renewable source of raw materials coming from agriculture. The main advantage of the materials are mainly the local availability and simple renewability of the raw materials. In addition an easy recycling of the materials after their service life end in the building construction and last but not least also the connection of human friendly properties of organic materials with advanced product manufacture qualities of modern insulation materials.


2021 ◽  
pp. 45-52
Author(s):  
G.I. Petrov ◽  
V.N. Kornienko ◽  
A.G. Donetskikh

Improving energy efficiency and energy saving in refrigeration technology depends largely on the use of modern thermal insulation materials in the thermal insulation structures of refrigeration pipelines. The article presents a comparative analysis of the thermal characteristics and operational properties of heat-insulating materials used in refrigeration. The features of RUFLEX thermal insulation materials based on foamed synthetic rubber produced from domestic raw materials and their compliance with the requirements of energy efficiency, durability, operational reliability and safety are considered.


2013 ◽  
Vol 772 ◽  
pp. 178-181
Author(s):  
Yong Liang Zhan ◽  
Hai Yang Chen ◽  
Xing Hua Hou ◽  
Fei He

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.


2014 ◽  
Vol 564 ◽  
pp. 315-320 ◽  
Author(s):  
Maatouk Khoukhi ◽  
Mahmoud Tahat

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.


2019 ◽  
Vol 10 (2) ◽  
pp. 78-91
Author(s):  
A. V Bolotin ◽  
S. M Sergeev ◽  
A. A Lunegova ◽  
E. A Kochetkova

Modern technologies are not standing still, and scientists are trying not only to invent new building materials, but also to find non-standard use of various raw materials that were previously considered unsuitable for use. Innovative technologies are actively used for modern construction of buildings, in particular, some types of new materials are used in the construction of various facilities. This is especially true in areas where it is not possible to import or use ordinary building materials for various reasons. Often, when designing a building, developers are wondering whether it is worth making the house warm during construction, and which insulation for the walls of the house is better to choose. This article addresses the question of which insulation for walls is most suitable for construction. The most common are mineral insulation, which are represented on the market today in the form of basalt slabs, fiberglass, etc. They have such advantages as low thermal conductivity, good thermal insulation and vapor permeability. The article presents a table with comparative performance characteristics of a mineral wool stone slab and a fiberglass slab. Stone or basalt wool has several advantages. It is able to withstand significant temperatures and temperature changes, the mats are easy to transport, convenient to install. In our opinion, a serious alternative to basalt in the production of thermal insulation materials is volcanic ash. One of the main features of volcanic ash are its building qualities, such as good thermal insulation and an environmentally friendly composition. Since here we are considering the possibility of producing insulation materials based on volcanic ash, we performed a thermal calculation of the enclosing structures. Also in the tables are the costs of transportation of volcanic ash from the field to the point of the proposed production of insulating material. Volcanic ash can be widely used in countries with high volcanic activity as an inexpensive raw material for the manufacture of building materials. It does not require additional processing and has a number of useful properties.


2019 ◽  
Vol 27 (1) ◽  
pp. 52-59 ◽  
Author(s):  
David Bozsaky

Abstract In the 21st century, global climate change and the high level of fossil energy consumption have introduced changes affecting all sectors of the economy, including the building industry. Reducing energy consumption has become an important task for engineers because 30% of the total energy consumption is used for heating our buildings. Recycling the huge amount of industrial and agricultural by-products has also become urgent because due to their CO2 emissions, their combustion is not a state-of-the-art alternative. Besides rediscovering some long-known, nature-based insulating materials, there are also several research projects that have resulted in new products. In the last century it was relatively easy to review this product range, but nowadays there are so many kinds of nature-based thermal insulating products, there is a need for systematization, and more in-depth knowledge about them is required. The purpose of this paper is to develop a new systematization of nature-based thermal insulation materials, summarize the main knowledge about them, and indicate the direction of recent research and development.


2020 ◽  
Vol 12 (12) ◽  
pp. 4841
Author(s):  
Maria Teresa Ferrandez-Garcia ◽  
Antonio Ferrandez-Garcia ◽  
Teresa Garcia-Ortuño ◽  
Clara Eugenia Ferrandez-Garcia ◽  
Manuel Ferrandez-Villena

The manufacture of technical materials of mineral and synthetic origin currently used for thermal insulation in buildings consumes a large amount of energy and they are not biodegradable. In order to reduce the environmental problems generated by their manufacture, an increasing amount of research is being carried out on the use of renewable and ecological resources. Consequently, the use of plant fibers and natural adhesives in the development of new thermal insulating products is increasing worldwide. Palm trees were used as a replacement for wood in some traditional constructions in places with scarce wood resources. This paper discusses the use of palm pruning waste in the manufacture of particleboards, using citric acid as a natural binder. Five particle sizes of Washingtonia palm rachis were used as the raw material for manufacturing the boards and the citric acid content was set at 10% by weight, in relation to the weight of the rachis particles. Single-layer agglomerated panels were made, applying a pressure of 2.6 MPa and a temperature of 150 °C for 7 min. Twenty panels were produced and their density, thickness swelling, water absorption, modulus of rupture, internal bonding strength and thermal conductivity properties were studied. Smaller particle size resulted in better mechanical properties. The boards had an average thermal conductivity of 0.084 W/m·K, meaning that these boards could be used for thermal insulation in buildings.


2018 ◽  
Vol 149 ◽  
pp. 01078
Author(s):  
Aggeliki Skaropoulou ◽  
Afroditi Ntziouni ◽  
Dimitris Kioupis ◽  
Sotiris Tsivilis ◽  
Glikeria Kakali

Insulation elements are distinguished in inorganic fibrous and organic foamed materials. Foamed insulation materials are of great acceptance and use, but their major disadvantage is their flammability. In case of fire, they tend to transmit the flame producing toxic gases. In this paper, the synthesis and characterization of innovative inorganic insulation materials with properties competitive to commercial is presented. Their synthesis involves the mixing of inorganic raw material and water with reinforcing agent or/and foaming agent leading to the formation of a gel. Depending on raw materials nature, the insulation material is produced by freeze drying or ambient drying techniques of the gel. The raw material used are chemically benign and abundantly available materials, or industrial by-products and the final products are non-toxic and, in some cases, non-flammable. Their density and thermal conductivity was measured and found 0.02-0.06 g/cm3 and 0.03-0.04 W/mK, respectively.


2014 ◽  
Vol 541-542 ◽  
pp. 141-145
Author(s):  
Bo Liu ◽  
Shou De Wang ◽  
Shuai Yang ◽  
Chen Chen Gong ◽  
Ling Chao Lu

Cement-based foam insulation board is a lightweight thermal insulation and have a characteristic of energy saving. The effects of material constitution on the properties of mechanical properties, dry densityand thermal conductivity for thermal insulation materials. The subject of fast hardening sulphoaluminate cement as cementitious materials, polystyrene particles as a lightweight thermal insulation material, adding a certain amount of water reducer, cellulose ethers, air entraining agent to make thermal insulation materials. The experimental results shows that the appropriate material constitution is following: the cement-bead ratio is 12, the ratio is 0.65, the water-cement ratio is 0.4, the content of water reducer is 0.5%, the content of cellulose ether is 0.4%, the content of the air entraining agent is 0.4% .This mix ratio test of mechanical properties are: flexural strength is 0.72MPa, compressive strength is 1.24MPa, dry density is 375kg/m3, water content is 2.3%, water absorption is 10.8%, softening coefficient is 0.95 and coefficient of thermal conductivity is 0.053 W/ (m K).


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