Fill Insulation Research Articles

Fabrication and heat conduction performance investigation of a heat insulation conductive bonding layer for asphalt pavements

To improve the efficiency of deicing and snow melting on road surfaces, three types of pavement conductive bonding layers with heat insulation effects were prepared, and the conductive bonding layer snowmelt pavement structure with heat insulation effect was designed. The temperature increasing effect of the upper part and the cooling effect of the lower part of the insulating conductive bonding layer were studied under different electrifying times. The effects of different material compositions on the heat insulating effect of the conductive bonding layer for the road were analyzed, and the best heat insulating and conductive bonding layer was selected. Results indicate that the comprehensive performance of the modified waterborne epoxy resin conductive bonding layer is the best. Compared with the two other types of conductive bonding layers, the temperature increasing effect of the upper part of the modified waterborne epoxy resin conductive bonding layer is 21.11–127.78% higher, and the cooling effect of the lower part is 19.78–93.62% higher. The addition of a heat insulation filler effectively improves the effect of the heat insulation conductive bonding layer, and with the increase in carbon fiber spreading amount, the performance improvement range of the road heat insulating conductive bonding layer increases gradually. The use of 80 g/m2 of modified waterborne epoxy resin/hollow glass bead as the conductive bonding layer is recommended.

Study of thermal insulation materials influence on the performance of thermoelectric generators by creating a significant effective temperature difference

Thermoelectric generator are attractive heat engines because they can convert heat directly into electricity via Seebeck effect. However, the energy conversion efficiency of today’s thermoelectric generators is significantly lower than that of conventional mechanical engines. Materials and devices are the main direction of its improvement. Although thermoelectric material has been making some progress, actual thermoelectric devices has remained stagnant with rather poor efficiencies. In this paper, a mathematical model containing heat losses ignored by previous studies are developed and used to discuss how to reduce heat losses to improved thermoelectric performance. In order to reduce and eliminate the impact of heat loss and study the effects of heat loss, the segmented thermoelectric modules filling with different insulation fillers are built to verify the accuracy of the model. Self-made experimental instruments are developed to study of the effect of reducing module heat loss on thermoelectric conversion performance. The results show that the filling of insulation materials makes contribution to the improvement of thermoelectric performance, the efficiency of aerogel filled module is 8.225% higher than that of unfilled module, and the efficiency of thermoelectric module can be improved up to 9.12% by adding ideal thermal insulation materials. The results also showed that the performance of TE module depends on the thermal conductivity of filling materials and its’ filling rate. Those results provided some practical guidelines for the design and improvement of practical thermoelectric modules.

Designing insulation filled masonry blocks against hygrothermal deterioration

Due to increasingly stringent requirements in building energy performance, further development of fired clay masonry blocks are essential nowadays for the manufacturers. One of the possible directions for improving thermal performance of the masonry blocks is to fill them with insulating materials. The currently developed bricks are most commonly containing mineral wool thermal insulation filler. The main criteria for manufacturers to develop their products are thermal performance and manufacturability, which leads to unsolved hygrothermal questions. While the filler materials have low thermal conductivities, they may deteriorate in high humidity environment and due to freeze-thaw cycles. The aim of this research is to test existing filled building blocks, to prevent hygrothermal deterioration. The study compares one-dimensional monthly based steady state Glaser method with steady state two-dimensional hygrothermal simulations and dynamic multi-dimensional conjugated heat and moisture transfer simulations. The calculations were made considering Central European Budapest climate. Hygrothermal material properties were measured in laboratory. After the calculations, results show that effective thermal transmittance, maximum freezing depth from the external surface of the plastered masonry blocks and the number of freeze-thaw cycles during a year vary depending on the facade's orientation. The possible freezing zone can reach one third of the masonry block from the external side, and affect the thermal performance of the bricks. The outermost insulation layers of the masonry blocks therefore must selected to bear freeze-thaw cycles and high humidity because of protection aspects. The new aspects of this study can be used to extend the application limits of insulation filled masonry blocks and design these type of masonry blocks against hygrothermal deteroriation.

Complex Pyrometallurgical Processing of Silicate Raw Material and Technogenic Waste into Market Products

A new approach to solving the problem of complex nonwaste processing of bottom ash waste (BAW) of low-grade metallic and nonmetallic feeds has been set forth. The solution is based on deep recreative melting of various burden materials with dividing the flux into a metallic phase and a silicate part that virtually does not contain any metal oxides. It has been shown that, depending on the method of producing the flux, various materials are generated: a foamed X-ray amorphous material (foamed silicate) with a stable formulation, a fine mineral fiber or spheres depending on technological modes. It follows from this work that the obtained foamed material is a semiproduct used as a fill insulation, a raw material for manufacturing foam ceramics and optically transparent glasses in the visible and near-IR ranges, and a sorbent for collection of oil products. On the basis of the experimental data, an industrial waste processing facility has been developed.

Fabrication of hollow silica nanosphere and its application for thermal insulation coating

Hollow silica nanospheres (HSNs) were synthesized via sol–gel method followed by calcination, using positively charged polystyrene (PS) as a hard template, and the tetraethoxysilane as precursor. The inner diameter and shell thickness of the HSNs can be expediently controlled by adjusting the particle size of PS and the amount of ammonia, respectively. The average inner diameters of HSNs increased from 153 nm to 255 nm along with the increasing PS particle size from 150 nm to 300 nm. The shell thickness of HSNs decreased from 20 nm to 12 nm with the increasing amount of ammonia from 1.5 mL to 3.0 mL. The structure of HSNs was verified by Fourier-transform infrared, thermogravimetric, scanning electron microscopy, and transmission electron microscopy characterization. The prepared thermal insulation coating comprised of HSNs shows good temperature retention and thermo-insulating properties, which indicate that the as-prepared HSNs are potentially used as an inorganic filler for thermal insulation coating.

The thermo-mechano-chemical twin-screw reactor, a new perspective for the biorefinery of sunflower whole plant: aqueous extraction of oil and other biopolymers, and production of biodegradable fiberboards from cake

Biorefinery of sunflower whole plant was performed successfully using a thermo-mechano-chemical twin-screw reactor. This led to the aqueous extraction of oil and other biopolymers like proteins, pectins and non pectic sugars. It resulted in the overall fractionation of biomass, thus allowing a complete valorization of the input. This biorefinery process was not only efficient but it was also environment-friendly. In addition, it contributed to the production of different end products for various industrial applications. Firstly, the hydrophilic phase will be recycled to the process. Secondly, the densest oil-in-water emulsion is a promising candidate for the formulation of cosmetic creams. Thirdly, the upper hydrophobic phase will be usable for the waterproofing treatment of the surface of agromaterials by coating. Its demixing will also lead to the production of proteins with tensioactive properties. These will serve for the food industry. Lastly, the cake was a mixture of plasticized proteins and lignocellulosic fibers. It was thus considered as a natural composite. Its molding into cohesive fiberboards was conducted successfully using both thermopressing and compression molding processes. The self-bonded boards with high density will be suitable for use as load bearing boards in dry conditions (floor underlayers, interior partitions, furniture, etc.). Positioned in walls and ceilings, boards with medium and low density will contribute to the heat insulation of buildings. In addition, the bulk cake will be also usable as a loose fill insulation material. As proposed, this flow chart thus allows a valorization for all fractions originating from the twin-screw reactor.

Transition Temperature Behaviour in Pan Based Composite Materials with and without SIC Filler

This article focus on the study of Transition or Back wall Temperature behavior in PAN based composite materials with and without Silicon Carbide filler was investigated. PAN fabric is one of the most useful reinforcement materials in the composites, its major use being the manufacture of components in aerospace, automotive and missile technology. In this study, PAN carbon fabric laminates were prepared by Hand lay-up technique with and without Silicon Carbide filler. The experimental work was done on studying the Transition or Back wall Temperature characterization and ablative studies through Oxy-acetylene testing. The study results revealed that it exhibits the better thermal protection shield in PAN based Silicon Carbide filler laminate compared without adding filler material. However, the ablation rate study results were exhibits better erosion rate of CP laminate with Sic filler for thermal insulation.

Permittivities of Ultra-Low Dielectric Silica Beads and Aerogels

Materials with relative permittivity or dielectric constant near to that of air (εr~1) are known as ‘ultra-low k’ materials. They find a number of applications in inter-connects of micro-electronic circuits, antennae, high-speed communication substrates etc. Among the inorganic materials, porous silica is the widely studied candidate. Porous silica can be of many types depending upon the extent of porosity and size and connectivity of pores. This paper presents the details of measurement of permittivities and the results of silica beads and silica aerogels. Silica beads, prepared by microwave heating of silica gels, are spherical beads of average 1mm size. Hydrophobic silica aerogels, prepared by ambient pressure drying of silica gels, are irregular chunks of 5-10 mm size. Both are potential bulk fill insulation materials and hence the permittivity can be measured as an aggregate filling a definite volume. The permittivities of these have been measured upto 1 MHz by 3-terminal method using a precision LCR meter and a powder-paste cell as per ASTM-D150-11. The εr values of silica aerogels and silica beads in 20 Hz-1 MHz range could be measured and are less than 1.6 at 1 MHz.

Recycling of Polystyrene Waste in the Composition of Ecological Mortars

Abstract As part of sustainable development, an important objective of constructors is the elaboration of a technology that may lead to the manufacture of new building materials and their implementation so as to contribute to the protection of the environment and natural resources, as well as to the creation of healthy living conditions. This study presents technologies for the manufacture of new building materials by polystyrene waste recycling. The following are produced: an ecological plastering mortar whose thermal conductivity is three times lower than that of ordinary mortar, which recommends it as a thermal insulation plastering mortar; three thermal insulation fillers, of which one is also recommended to be used as panels for external thermal insulation systems. All these are supported by the results obtained following the laboratory determinations presented in the paper.

Laboratory Research on Composite Tunnel Fire-Retardant Coating

Through conducting a fire resistance test as well as other physical and chemical property tests, an optimized ratio of composite binder, inorganic heat insulation fillers, and forming material was determined for the manufacture of a tunnel fire-retardant coating. The manufactured coating exhibited favorable physical and chemical performances. The experimentally obtained results support that this coating has a higher fire resistance and adhesive property in comparison to the majority of existing tunnel fire coatings.

Study on the Properties of Geocement Based Thermal Insulating Materials for High Temperature Technical Appliances

Three different types ofgeocement thermal insulation materials for energy storage unit were selected after preliminary test. Perlite and vermiculite were added as thermal insulation fillers during mixing process. The produced materials were subjected to heat treatment before determining their properties. The materials produced are characterized by low density (321–376 kg/m3) and thermal conductivity (0.0727 – 0.0766 W/mK). These materials ensure the minimum heat losses of the energy storage unit if the temperature of the medium is 318–923 K and the thickness of thermal insulation layer is 153–160 mm.

Development of Building Elements with Thermal Insulation Filler Based on Secondary Raw Materials

With increasing requirements for properties of envelope design in respect of thermal protection of buildings also requirements for building material properties have been growing. In case of ceramic shaped pieces for peripheral structures the way to further improvement of its thermal insulation properties is quite difficult. Generally thickness of interior groins can be reduced and its geometrical layout changed or the ceramics blocks dimensions increased and thus width of the masonry construction. Use of insulation filler integrated in block cavities is the alternative technology of production of insulation special shapes of high insulation properties. In these cases the ceramic fragment ensures the mechanical stability of the block and integrated insulation layer in smaller or bigger part (depending on its part) the thermal properties and eventually also the acoustic and insulation ones. The paper describes application possibilities of insulation materials based upon waste textile fibres as integrated layer in current masonry ceramic blocks of high utility properties.

다공성 실리카 에어로겔을 이용한 복합단열재의 특성에 관한 연구

High porous silica aerogel/polyurethane polymer composite was manufactured by cross-linking polymeriza tion of polyurethane foaming process. The properties of microstructure, mechanical strength, and thermal properties were investigated for its various applications. The superhydrophobic silica aerogel powders were used for highly thermal insulation filler materials. The thermal conductivities can be resulted 0.07 W/mK to 0.13 W/mK, by decreasing the contents of silica aerogels in composite materials. It is found that the polymerization formulation by organic binders can be applied to heavy industires, building materials, and various industries.

Study on Water-Based Highly Reflectivity Insulation Coating

The paper researched a solar heat-reflective insulation coating method, investigating coating morphology and other factors affecting the performance of thermal insulation, such as membrane material and the type of insulation pigments as well as pigment to binder ratio. It used solar heat reflectivity and infrared spectroscopy to characterize the coating thermal insulation performance. The results showed that with the silane coupling agent for the bonded dispersant, the flake aluminum powder and titanium dioxide for the thermal insulation filler, together with water and additives, the average reflectance of visible light is 56%, the UV reflectance is 53%, the infrared reflectivity is 58%.

Experimental investigation of the influence of air conduction on heat transfer across fibrous materials

Accurate prediction of the effective thermal conductivity of loose fill fibrous building thermal insulation remains a challenging issue to date. Most researchers considered the complex problem of heat transfer across a fibrous material to be the sum of heat transfer due to air conduction, solid conduction and radiation for which general empirical relationships were developed from reliable thermal conductivity tests. In this study, an experimental investigation of this hypothesis was undertaken by removing the air from a porous material, hence, theoretically leaving heat transfer due to solid conduction and radiation only. This hypothesis was tested by conducting steady state thermal conductivity measurements under vacuum conditions for coconut fiber and sugarcane fiber specimens. Test results indicated an average difference between the thermal conductivity at atmospheric conditions and under vacuum conditions of 0.0279 and 0.0231 W/m.K for coconut fiber and sugarcane fiber, respectively, over the density range tested. The experimental results were in agreement with the widely expressed opinion that air behaves as an independent individual contributor to the overall effective thermal conductivity of a loose fill fibrous material. Key words: Fibrous insulation, thermal conductivity, loose fill insulation, effective thermal conductivity, air conduction.

Thermal Insulation Coatings Containing Sepiolite Mineral Fibers and their Performance

In this text, the effective thermal conductivity of different shape filler particles was investigated. The thermal insulation coatings were prepared using hollow glass beads and sepiolite as thermal insulation fillers and the thermal insulation effect was evaluated. The results show that the optimum ratio of sepiolite and hollow glass beads is 6:1, and the temperature difference of upper box and lower box is up to 18 °C. The main reason for this phenomenon is that the thermal conduction chain is difficult to form in the direction of heat flow, thus leading to the increase of thermal resistance and decrease of thermal conductivity.

Field Coil Insulation Testing for Pulse Power Alternators

Current pulse power alternator designs operate at high speeds and high current densities. The field coil insulation systems for pulse power alternators must provide sufficient stand-off voltage while limiting the amount of thermal resistance for actively cooled designs, and also withstand the strain excursions experienced at full operating speed. Repetitive cycling of the strain excursion overtime may induce cracks in the surrounding field coil matrix. The primary insulation surrounding the field coil conductors must be able to stop crack propagation that may develop in the surrounding matrix material and provide voltage hold-off. Thermally conductive thermoplastics are currently being investigated for the field coil matrix materials where decreased thermal resistance is necessary for actively cooled field coil designs. In order to evaluate conductor insulation and thermoplastic matrix filler quickly, small coupon motorettes were developed per previous designs. The motorettes simulate the hoop strain the conductors would experience due to rotor growth at high rotational speeds. Once the motorettes had been mechanically loaded, the coupon was hi-potted to verify insulation integrity under strain. This paper will discuss the design and testing of these motorettes to evaluate thermally conductive thermoplastics as filler material for the field coil matrix

Efficiency of use of thermal insulation fillers for steel ingots quality improvement

Efficiency of use of thermal insulation fillers for steel ingots quality improvement

Moisture Conditions in a North Facing Wall with Cellulose Loose Fill Insulation: Constructions with and without Vapor Retarder and Air Leakage

This paper presents calculated moisture conditions of a wall exposed to a climate equivalent to the North of Sweden. A north facing timber wall with a brick facade and cellulose loose fill thermal insulation is studied both with and without vapor retarder and air leakage. If the vapor retarder is eliminated from the construction, the moisture levels will increase to unacceptable high values. The con struction becomes sensitive to the choice of facing materials and the indoor moisture supply. Air leakage carrying moist air into the construction leads to unacceptably high values even for moderate indoor moisture supplies.

Advanced insulations for refrigerator/freezers: the potential for new shell designs incorporating polymer barrier construction

The impending phase-out of chlorofluorocarbons (CFCs) used to expand foam insulation, combined with requirements for increased energy efficiency, make the use of non-CFC-based high performance insulation technologies increasingly attractive. The majority of current efforts are directed at using advanced insulations in the form of thin, flat low-conductivity gas-filled or evacuated orthogonal panels, which we refer to as Advanced Insulation Panels (AIPs). AIPs can be used in composite with blown polymer foams to improve insulation performance in refrigerator/freezers (R/Fs) of conventional design and manufacture. This AIP/foam composite approach is appealing because it appears to be a feasible, near-term method for incorporating advanced insulations into R/Fs without substantial redesign or retooling. However, the requirements for adequate flow of foam during the foam-in-place operation impose limitations on the allowable thickness and coverage area of AIPs. This report examines design alternatives which may offer a greater increase in overall thermal resistance than is possible with the use of AIP/foam composites in current R/F design. These design alternatives generally involve a basic redesign of the R/F taking into account the unique requirements of advanced insulations and the importance of minimizing thermal bridging with high thermal resistance insulations. The focus here is on R/F doors becausemore » they are relatively simple and independent R/F components and are therefore good candidates for development of alterative designs. R/F doors have significant thermal bridging problems due to the steel outer shell construction. A three dimensional finite difference computer modeling exercise of a R/F door geometry was used to compare the overall levels of thermal resistance (R-value) for various design configurations.« less