scholarly journals Preparation and Characterization of a Type of Green Vacuum Insulation Panel Prepared with Straw Core Material

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4604
Author(s):  
Lu Wang ◽  
Yong Yang ◽  
Zhaofeng Chen ◽  
Yiyou Hong ◽  
Zhou Chen ◽  
...  

The Vacuum Insulation Panel (VIP), regarded as the most promising high-performance thermal insulation material, still has application limitations because of its high cost. In this paper, VIPs using natural straw as the core material are prepared. The fiber saturation point (FSP) is important in order to determine the optimum for the use of renewable straw materials as a potential VIP core. The microstructure of straw core material, together with the relationship between the moisture content, the diametral compression strength, and the thermal conductivity of as-prepared straw VIPs are investigated. Compression characteristics of straw core material and heat insulation mechanism within the straw VIP envelope enclosure are analyzed. Total thermal conductivity of a straw VIP is sensitive to both the inner pressure and the moisture content of straw core material. The optimum drying process for straw VIPs is heating the straw core material at a temperature of 120 ℃ for 60 min, with its center-of-panel value being about 3.8 mW/(m·K).

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 3339-3351 ◽  
Author(s):  
Baowen Wang ◽  
Zhihui Li ◽  
Xinglai Qi ◽  
Nairong Chen ◽  
Qinzhi Zeng ◽  
...  

Wood fibers were prepared as core materials for a vacuum insulation panel (VIP) via a dry molding process. The morphology of the wood fibers and the microstructure, pore structure, transmittance, and thermal conductivity of the wood fiber VIP were tested. The results showed that the wood fibers had excellent thermal insulation properties and formed a porous structure by interweaving with one another. The optimum bulk density that led to a low-cost and highly thermally efficient wood fiber VIP was 180 kg/m3 to 200 kg/m3. The bulk density of the wood fiber VIP was 200 kg/m3, with a high porosity of 78%, a fine pore size of 112.8 μm, and a total pore volume of 7.0 cm3·g-1. The initial total thermal conductivity of the wood fiber VIP was 9.4 mW/(m·K) at 25 °C. The thermal conductivity of the VIP increased with increasing ambient temperature. These results were relatively good compared to the thermal insulation performance of current biomass VIPs, so the use of wood fiber as a VIP core material has broad application prospects.


2012 ◽  
Vol 430-432 ◽  
pp. 741-745
Author(s):  
Juan Zhang ◽  
Zhao Feng Chen ◽  
Jie Ming Zhou ◽  
Bin Bin Li ◽  
Zhou Chen

VIP (Vacuum insulation panel), as a high performance insulation component, combine with limited thickness, have recently been introduced to numerous energy conservation applications. VIP consists of a highly insulating core material and a gas tight barrier envelope which is generally composed of plastic film and aluminum film. When the envelope is stainless steel sheet, VIP is called VIS (vacuum insulation sandwich). Because of this hardly permeable rigid barrier, VIS presents more fantastic properties such as resistance against external mechanical loads and penetration of atmospheric gases and water vapor. Consequently, the service life of VIS is significantly longer than that of VIP. Detailed structure and some practical applications of VIS elements are also reviewed in this paper.


2013 ◽  
Vol 50 ◽  
pp. 1030-1037 ◽  
Author(s):  
Cheng-Dong Li ◽  
Zheng-Cai Duan ◽  
Qing Chen ◽  
Zhao-Feng Chen ◽  
Fred Edmond Boafo ◽  
...  

2018 ◽  
Vol 9 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Á. Lakatos ◽  
I. Deák ◽  
U. Berardi

The development of high performance insulating materials incorporating nanotechnologies has enabled considerable decrease in the effective thermal conductivity. Besides the use of conventional insulating materials, such as mineral fibers, the adoption of new nano-technological materials such as aerogel, vacuum insulation panels, graphite expanded polystyrene, is growing. In order to reduce the thermal conductivity of polystyrene insulation materials, during the manufacturing, nano/micro-sized graphite particles are added to the melt of the polystyrene grains. The mixing of graphite flakes into the polystyrene mould further reduces the lambda value, since graphite parts significantly reflect the radiant part of the thermal energy. In this study, laboratory tests carried out on graphite insulation materials are presented. Firstly, thermal conductivity results are described, and then sorption kinetic curves at high moisture content levels are shown. The moisture up-taking behaviour of the materials was investigated with a climatic chamber where the relative humidity was 90% at 293 K temperature. Finally, calorific values of the samples are presented after combusting in a bomb calorimeter.


2012 ◽  
Vol 446-449 ◽  
pp. 3753-3756 ◽  
Author(s):  
Wang Ping Wu ◽  
Zhao Feng Chen ◽  
Jie Ming Zhou ◽  
Xue Yu Cheng

The VIPs consist of the glass-fiber core material and two types of envelope film. The glass fiber was fabricated by a centrifugal blowing process. The core material was prepared by the wet method. The thermal conductivities of the core material and VIPs were measured by the heat flow meter. The thermal conductivity for six pieces of 1mm thick core material is less than that for one piece of 6mm thick core material, which is affected by the fiber diameter, porosity ratio and the largest pore size diameter. The VIP for the building material has a low thermal conductivity (<0.008W/mK). The VIP for the home appliance has a lower thermal conductivity (<0.003W/mK). The VIP maintains a high-uniform thermal conductivity values due to the getter effect.


2014 ◽  
Vol 21 (4) ◽  
pp. 521-527 ◽  
Author(s):  
Metin Davraz ◽  
Hilmi C. Bayrakci

AbstractVacuum insulation panel (VIP) is known to be the most effective insulation material. However, the usage areas of VIPs are restricted because of their high production costs. The core of VIP is the most important item affecting the cost of VIP. In this study, to obtain VIPs, which are provided with minimum thermal conductivity resistance value (R=5 m2 K/mW), was aimed for the optimal thickness of the panel (<40 mm). Therefore, 14 different core samples of VIP were produced by using various types of powders (fumed silica, precipitated silica, perlite, and diatomite), opacifiers (silicon carbide, carbon black, and titanium dioxide), and fibers (glass fiber, organic fiber, and cellulosic fiber). By using appropriate test methods, the physical properties of core samples such as unit weight, porosity, mass per volume and mechanical properties, their uniaxial compressive strength, tensile strength, and dimensional stability and also thermal conductivity coefficient in vacuum were determined. Results were compared with values of reference materials. The most appropriate compression pressure used in the manufacture of core sample was 27.5 kN. In addition, taking into account the benefit-cost relationship, the results of this study showed that the mix of fumed silica and precipitated silica (powder material), silicon carbide (opacifier), and glass fiber (fiber) was determined as the most suitable raw materials.


2012 ◽  
Vol 174-177 ◽  
pp. 1437-1440 ◽  
Author(s):  
Cheng Dong Li ◽  
Zhao Feng Chen ◽  
Wang Ping Wu ◽  
Zhou Chen ◽  
Jie Ming Zhou ◽  
...  

Vacuum insulation panels (VIPs) are regarded as one of the most promising high performance thermal insulation solutions on the market today. The insulation performance of VIPs mainly depends on the quality of core materials. This paper compared three types of core materials, namely foam insulation material, powder insulation material and fibrous insulation material. Novel structure of core materials which is fiber pore structures packed with different size powder particles is also put forward on this paper. The aim of this paper is to investigate and compare various properties, requirements and possibilities for traditional core materials and put forward possible future core materials of VIPs.


2011 ◽  
Vol 117-119 ◽  
pp. 1067-1070
Author(s):  
Jun Ji ◽  
Hou De Han ◽  
An Kang Kan

Vacuum insulation panels are distinguished by their outstandingly low thermal conductivity, which is approximately 0.004 W/ (m • K) to 0.01 W/ (m • K), only 33% to 10% of that of the traditional heat preservation materials. The heat preservation mechanism of vacuum insulation panels is elaborated in the study. The thermal conductivity of the vacuum insulation panel made in our lab were below 0.01 W/ (m • K). By analysis and calculation, with this kind of VIPs applied to refrigerated containers, its exciting properties can save energy consumption by more than 20% compared with traditional heat preservation materials.


2012 ◽  
Vol 178-181 ◽  
pp. 46-50
Author(s):  
Wang Ping Wu ◽  
Zhou Chen ◽  
Cheng Dong Li ◽  
Teng Zhou Xu ◽  
Jin Lian Qiu ◽  
...  

The insulation material VIP in building offers a new material for highly insulated constructions with just a fraction of the required insulation thickness compared to conventional thermal insulation materials. A VIP is basically composed of the core material, the barrier film and getters. Core materials of VIP are glass fiber, fumed silica, fiber-powder composite core. The barrier film covered by glass fiber textile is the protection of the envelope against surface damage and fire attack. We introduce the VIP elements, the system of VIPs in building application and external thermal insulation system with VIP.


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