WorldWideScience

Sample records for thermal insulation

  1. Thermal insulator

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, R.; Asada, Y.; Matsuo, Y.; Mikoda, M.

    1985-07-16

    A thermal insulator comprises an expanded resin body having embedded therein an evacuated powder insulation portion which consists of fine powder and a container of film-like plastics or a film-like composite of plastics and metal for enclosing the powder. The resin body has been expanded by a Freon gas as a blowing agent. Since a Freon gas has a larger molecular diameter than the constituent gases of air, it is less likely to permeate through the container than air. Thus present invention provides a novel composite insulator which fully utilizes the benefits of vacuum insulation without necessitating a strong and costly material for a vacuum container.

  2. THERMAL INSULATION SYSTEMS

    Science.gov (United States)

    Augustynowicz, Stanislaw D. (Inventor); Fesmire, James E. (Inventor)

    2005-01-01

    Thermal insulation systems and with methods of their production. The thermal insulation systems incorporate at least one reflection layer and at least one spacer layer in an alternating pattern. Each spacer layer includes a fill layer and a carrier layer. The fill layer may be separate from the carrier layer, or it may be a part of the carrier layer, i.e., mechanically injected into the carrier layer or chemically formed in the carrier layer. Fill layers contain a powder having a high surface area and low bulk density. Movement of powder within a fill layer is restricted by electrostatic effects with the reflection layer combined with the presence of a carrier layer, or by containing the powder in the carrier layer. The powder in the spacer layer may be compressed from its bulk density. The thermal insulation systems may further contain an outer casing. Thermal insulation systems may further include strips and seams to form a matrix of sections. Such sections serve to limit loss of powder from a fill layer to a single section and reduce heat losses along the reflection layer.

  3. Perioperative thermal insulation.

    Science.gov (United States)

    Bräuer, Anselm; Perl, Thorsten; English, Michael J M; Quintel, Michael

    2007-01-01

    Perioperative hypothermia remains a common problem during anesthesia and surgery. Unfortunately, the implementation of new minimally invasive surgical procedures has not lead to a reduction of this problem. Heat losses from the skin can be reduced by thermal insulation to avoid perioperative hypothermia. However, only a small amount of information is available regarding the physical properties of insulating materials used in the Operating Room (OR). Therefore, several materials using validated manikins were tested. Heat loss from the surface of the manikin can be described as:"Q = h . DeltaT . A" where Q = heat flux, h = heat exchange coefficient, DeltaT = temperature gradient between the environment and surface, and A = covered area. Heat flux per unit area and surface temperature were measured with calibrated heat flux transducers. Environmental temperature was measured using a thermoanemometer. The temperature gradient between the surface and environment (DeltaT) was varied and "h" was determined by linear regression analysis as the slope of "DeltaT" versus heat flux per unit area. The reciprocal of the heat exchange coefficient defines the insulation. The insulation values of the materials varied between 0.01 Clo (plastic bag) to 2.79 Clo (2 layers of a hospital duvet). Given the range of insulating materials available for outdoor activities, significant improvement in insulation of patients in the OR is both possible and desirable.

  4. Peg supported thermal insulation panel

    Science.gov (United States)

    Nowobilski, Jeffert J.; Owens, William J.

    1985-01-01

    A thermal insulation panel which is lightweight, load bearing, accommodates thermal stress, and has excellent high temperature insulation capability comprising high performance insulation between thin metal walls supported by high density, high strength glass pegs made in compliance with specified conditions of time, temperature and pressure.

  5. Variable pressure thermal insulating jacket

    Science.gov (United States)

    Nelson, Paul A.; Malecha, Richard F.; Chilenskas, Albert A.

    1994-01-01

    A device for controlled insulation of a thermal device. The device includes a thermal jacket with a closed volume able to be evacuated to form an insulating jacket around the thermal source. A getter material is in communcation with the closed volume of the thermal jacket. The getter material can absorb and desorb a control gas to control gas pressure in the volume of the thermal jacket to control thermal conductivity in the thermal jacket.

  6. Thermal Insulation Test Apparatuses

    Science.gov (United States)

    Berman, Brion

    2005-01-01

    The National Aeronautics and Space Administration (NASA) seeks to license its Thermal Insulation Test Apparatuses. Designed by the Cryogenics Test Laboratory at the John F. Kennedy Space Center (KSC) in Florida, these patented technologies (U.S. Patent Numbers: Cryostat 1 - 6,742,926, Cryostat 2 - 6,487,866, and Cryostat 4 - 6,824,306) allow manufacturers to fabricate and test cryogenic insulation at their production and/or laboratory facilities. These new inventions allow for the thermal performance characterization of cylindrical and flat specimens (e.g., bulk-fill, flat-panel, multilayer, or continuously rolled) over the full range of pressures, from high vacuum to no vacuum, and over the full range of temperatures from 77K to 300K. In today's world, efficient, low-maintenance, low-temperature refrigeration is taking a more significant role, from the food industry, transportation, energy, and medical applications to the Space Shuttle. Most countries (including the United States) have laws requiring commercially available insulation materials to be tested and rated by an accepted methodology. The new Cryostat methods go beyond the formal capabilities of the ASTM methods to provide testing for real systems, including full-temperature differences plus full-range vacuum conditions.

  7. Industrial thermal insulation: an assessment

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, R.G.; Tennery, V.J.; McElroy, D.L.; Godfrey, T.G.; Kolb, J.O.

    1976-03-01

    A large variety of thermal insulation materials is manufactured for application in various temperature ranges and environments. Additional and improved thermal insulation for steam systems is a key area with immediate energy conservation potential in several of the larger energy-consuming industries. Industrial thermal insulation technology was assessed by obtaining input from a variety of sources including insulation manufacturers, system designers, installers, users, consultants, measurement laboratories, open literature, and in-house knowledge. The assessment identified a number of factors relevant to insulation materials and usage that could contribute significantly to improved energy conservation.

  8. Handbook of Thermal Insulation Applications.

    Science.gov (United States)

    1983-01-01

    Transfer in Low-Density Insulation." Journal of Thermal Insulation. Technomic Publishing Co., Inc. Vol. 1, pp. 37-61. July 1979. Rockwool Industries...Inc. "Blowing Wool" Technical Rulletins #6, #8, #9, and #10. Englewood, CO. Aug. 1981. Rockwool Industries, Inc. "Facts About Home Insulation." No...78120. Denver, CO. 1981. Rockwool Industries, Inc. "Multi-layer Foil." Technical Bulletin #5. Englewood, CO. Aug. 1981. Roofing, Siding and Insulation

  9. Hybrid Multifoil Aerogel Thermal Insulation

    Science.gov (United States)

    Sakamoto, Jeffrey; Paik, Jong-Ah; Jones, Steven; Nesmith, Bill

    2008-01-01

    This innovation blends the merits of multifoil insulation (MFI) with aerogel-based insulation to develop a highly versatile, ultra-low thermally conductive material called hybrid multifoil aerogel thermal insulation (HyMATI). The density of the opacified aerogel is 240 mg/cm3 and has thermal conductivity in the 20 mW/mK range in high vacuum and 25 mW/mK in 1 atmosphere of gas (such as argon) up to 800 C. It is stable up to 1,000 C. This is equal to commercially available high-temperature thermal insulation. The thermal conductivity of the aerogel is 36 percent lower compared to several commercially available insulations when tested in 1 atmosphere of argon gas up to 800 C.

  10. Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

    OpenAIRE

    Smajo Sulejmanovic; Suad Kunosic; Ema Hankic

    2014-01-01

    This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to r...

  11. Thermal Response Of Composite Insulation

    Science.gov (United States)

    Stewart, David A.; Leiser, Daniel B.; Smith, Marnell; Kolodziej, Paul

    1988-01-01

    Engineering model gives useful predictions. Pair of reports presents theoretical and experimental analyses of thermal responses of multiple-component, lightweight, porous, ceramic insulators. Particular materials examined destined for use in Space Shuttle thermal protection system, test methods and heat-transfer theory useful to chemical, metallurgical, and ceramic engineers needing to calculate transient thermal responses of refractory composites.

  12. Multipurpose Thermal Insulation Test Apparatus

    Science.gov (United States)

    Fesmire, James E. (Inventor); Augustynowicz, Stanislaw D. (Inventor)

    2002-01-01

    A multi-purpose thermal insulation test apparatus is used for testing insulation materials, or other components. The test apparatus is a fluid boil-off calorimeter system for calibrated measurement of the apparent thermal conductivity (k-value) of a specimen material at a fixed vacuum level. The apparatus includes an inner vessel for receiving a fluid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including the inner vessel and thermal guards, is suspended from the top of the vacuum chamber. Handling tools attach to the cold mass assembly for convenient manipulation of the assembly and for the installation or wrapping of insulation test materials. Liquid nitrogen is typically supplied to the inner vessel using a fill tube with funnel. A single port through the top of the vacuum chamber facilitates both filling and venting. Aerogel composite stacks with reflective films are fastened to the top and the bottom of the inner vessel as thermal guards. The comparative k-value of the insulation material is determined by measuring the boil-off flow rate of gas, the temperature differential across the insulation thickness, and the dimensions (length and diameters) of the test specimen.

  13. Thermal Insulation from Hardwood Residues

    Science.gov (United States)

    Sable, I.; Grinfelds, U.; Vikele, L.; Rozenberga, L.; Zeps, M.; Luguza, S.

    2015-11-01

    Adequate heat is one of the prerequisites for human wellbeing; therefore, building insulation is required in places where the outside temperature is not suitable for living. The climate change, with its rising temperatures and longer dry periods, promotes enlargement of the regions with conditions more convenient for hardwood species than for softwood species. Birch (Betula pendula) is the most common hardwood species in Latvia. The aim of this work was to obtain birch fibres from wood residues of plywood production and to form low-density thermal insulation boards. Board formation and production was done in the presence of water; natural binder, fire retardant and fungicide were added in different concentrations. Board properties such as density, transportability or resistance to particulate loss, thermal conductivity and reaction to fire were investigated. This study included thermal insulation boards with the density of 102-120 kg/m3; a strong correlation between density and the binder amount was found. Transportability also improved with the addition of a binder, and 0.1-0.5% of the binder was the most appropriate amount for this purpose. The measured thermal conductivity was in the range of 0.040-0.043 W/(m·K). Fire resistance increased with adding the fire retardant. We concluded that birch fibres are applicable for thermal insulation board production, and it is possible to diversify board properties, changing the amount of different additives.

  14. Local Thermal Insulating Materials For Thermal Energy Storage

    African Journals Online (AJOL)

    Unknown User

    1. Introduction. It is necessary to use thermal insulating materials around thermal energy storage systems to minimize heat losses from the systems [1]. There are varieties of insulating materials which come in various forms like loose fill, rigid boards, pipe and foam. The thermal insulation is provided by embedding insulation ...

  15. Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

    Directory of Open Access Journals (Sweden)

    Smajo Sulejmanovic

    2014-11-01

    Full Text Available This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.

  16. Thermal shock resistance ceramic insulator

    Science.gov (United States)

    Morgan, Chester S.; Johnson, William R.

    1980-01-01

    Thermal shock resistant cermet insulators containing 0.1-20 volume % metal present as a dispersed phase. The insulators are prepared by a process comprising the steps of (a) providing a first solid phase mixture of a ceramic powder and a metal precursor; (b) heating the first solid phase mixture above the minimum decomposition temperature of the metal precursor for no longer than 30 minutes and to a temperature sufficiently above the decomposition temperature to cause the selective decomposition of the metal precursor to the metal to provide a second solid phase mixture comprising particles of ceramic having discrete metal particles adhering to their surfaces, said metal particles having a mean diameter no more than 1/2 the mean diameter of the ceramic particles, and (c) densifying the second solid phase mixture to provide a cermet insulator having 0.1-20 volume % metal present as a dispersed phase.

  17. Flexible pile thermal barrier insulator

    Science.gov (United States)

    Anderson, G. E.; Fell, D. M.; Tesinsky, J. S. (Inventor)

    1978-01-01

    A flexible pile thermal barrier insulator included a plurality of upstanding pile yarns. A generally planar backing section supported the upstanding pile yarns. The backing section included a plurality of filler yarns forming a mesh in a first direction. A plurality of warp yarns were looped around said filler yarns and pile yarns in the backing section and formed a mesh in a second direction. A binder prevented separation of the yarns in the backing section.

  18. Improved Aerogel Vacuum Thermal Insulation

    Science.gov (United States)

    Ruemmele, Warren P.; Bue, Grant C.

    2009-01-01

    An improved design concept for aerogel vacuum thermal-insulation panels calls for multiple layers of aerogel sandwiched between layers of aluminized Mylar (or equivalent) poly(ethylene terephthalate), as depicted in the figure. This concept is applicable to both the rigid (brick) form and the flexible (blanket) form of aerogel vacuum thermal-insulation panels. Heretofore, the fabrication of a typical aerogel vacuum insulating panel has involved encapsulation of a single layer of aerogel in poly(ethylene terephthalate) and pumping of gases out of the aerogel-filled volume. A multilayer panel according to the improved design concept is fabricated in basically the same way: Multiple alternating layers of aerogel and aluminized poly(ethylene terephthalate) are assembled, then encapsulated in an outer layer of poly(ethylene terephthalate), and then the volume containing the multilayer structure is evacuated as in the single-layer case. The multilayer concept makes it possible to reduce effective thermal conductivity of a panel below that of a comparable single-layer panel, without adding weight or incurring other performance penalties. Implementation of the multilayer concept is simple and relatively inexpensive, involving only a few additional fabrication steps to assemble the multiple layers prior to evacuation. For a panel of the blanket type, the multilayer concept, affords the additional advantage of reduced stiffness.

  19. On vacuum-insulated thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Benjamin [Georg-Simon-Ohm Univ. of Applied Sciences, Nuernberg (Germany); Technische Univ. Muenchen (Germany). Inst. of Resource and Energy Technology; Hofbeck, Klaus [Georg-Simon-Ohm Univ. of Applied Sciences, Nuernberg (Germany)

    2011-07-01

    Nowadays, the insulation for thermal energy storage (TES) is not as good as it should be. One reason for this is the higher investment cost for better insulation. Nevertheless, most of the recent studies show that the thermal losses of long-term storage have been underestimated. Therefore, recent research studies have focused on vacuum-insulated thermal storage. There are two common concepts with regard to the use of vacuum insulation for thermal storage. On the one hand, the Center for Applied Energy Research (ZAE) in Munich uses an evacuated double vessel filled with pearlite. On the other hand, the Ohm University uses vacuum insulation panels (VIP). Both the insulation concepts are based on the Knudsen effect. Thus, the thermal conductivity is lowered by a factor of 6-10, when compared with the conventional insulation materials, such as EPS, XPS, or mineral wool. Both the concepts are adoptions of the existing insulation applications. The filled double vessel tank is already being used for cryogenic storage for liquid gases. Furthermore, VIPs are being used to insulate passive houses. However, the use of vacuum insulation for thermal energy storage causes different problems due to higher temperatures and moisture. Nevertheless, vacuum insulations are a promising solution for small thermal long-tenn storage. This study presents the first state-of-the-art review on vacuum-insulated thermal tanks.

  20. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

    Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

  1. Building ceramics with improved thermal insulation parameters

    OpenAIRE

    Rzepa Karol; Wons Wojciech; Reben Manuela

    2016-01-01

    One of the most important performance characteristics of masonry units is their high thermal insulation. There are many different ways to improve this parameter, however the most popular methods in case of ceramic masonry units are: addition of pore-creating raw materials and application of proper hole pattern. This study was an attempt to improve thermal insulation of ceramics by applying thermal insulation additives. Perlite dust created as a subgrain from expansion of perlite rock was used...

  2. Local Thermal Insulating Materials For Thermal Energy Storage ...

    African Journals Online (AJOL)

    Thermal insulation is one of the most important components of a thermal energy storage system. In this paper the thermal properties of selected potential local materials which can be used for high temperature insulation are presented. Thermal properties of seven different samples were measured. Samples consisted of: ...

  3. Sprayable Thermal Insulation for Cryogenic Tanks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Sprayable Thermal Insulation for Cryogenic Tanks (STICT) is a thermal management system applied by either an automated or manual spraying process with less...

  4. Quantitative analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

    This work concerns the development of simulation tools for mapping of insulation properties of thermal insulation coatings based on selected functional filler materials. A mathematical model, which includes the underlying physics (i.e. thermal conductivity of a heterogeneous two-component coating...

  5. Corrosion control under thermal insulation and fireproofing

    Energy Technology Data Exchange (ETDEWEB)

    Delahunt, J.F.

    1982-02-01

    Corrosion occurring on carbon steel which is protected by thermal insulation (mineral wool, fiberglass, foam glass, calcium silicate, phenolics, and polyurethanes) or by fireproofing material (concrete or gunite) is discussed. Examples are given and illustrated of corrosion in refineries, petrochemical plants, and pipelines which have been thermally insulated or fireproofed. Four corrosion mechanisms have been identified and are discussed. The promoting action of chlorides as well as the pH effect or corrosion are described and it is concluded that the corrosion under thermal insulation follows two patterns. Further, organic cellular foams (polyurethanes and phenolics) are shown to accelerate corrosive action. Stress corrosion cracking of stainless steel under thermal insulation is described and the effect of improper design/application is stressed. Specific measures to control corrosion are discussed for concrete fireproofing and thermal insulation. (MJJ)

  6. Thermal Insulation Strips Conserve Energy

    Science.gov (United States)

    2009-01-01

    Launching the space shuttle involves an interesting paradox: While the temperatures inside the shuttle s main engines climb higher than 6,000 F hot enough to boil iron for fuel, the engines use liquid hydrogen, the second coldest liquid on Earth after liquid helium. Maintained below 20 K (-423 F), the liquid hydrogen is contained in the shuttle s rust-colored external tank. The external tank also contains liquid oxygen (kept below a somewhat less chilly 90 K or -297 F) that combines with the hydrogen to create an explosive mixture that along with the shuttle s two, powdered aluminum-fueled solid rocket boosters allows the shuttle to escape Earth s gravity. The cryogenic temperatures of the main engines liquid fuel can cause ice, frost, or liquefied air to build up on the external tank and other parts of the numerous launch fueling systems, posing a possible debris risk when the ice breaks off during launch and causing difficulties in the transfer and control of these cryogenic liquid propellants. Keeping the fuel at the necessary ultra-cold temperatures while minimizing ice buildup and other safety hazards, as well as reducing the operational maintenance costs, has required NASA to explore innovative ways for providing superior thermal insulation systems. To address the challenge, the Agency turned to an insulating technology so effective that, even though it is mostly air, a thin sheet can prevent a blowtorch from igniting a match. Aerogels were invented in 1931 and demonstrate properties that make them the most extraordinary insulating materials known; a 1-inch-thick piece of aerogel provides the same insulation as layering 15 panes of glass with air pockets in between. Derived from silica, aluminum oxide, or carbon gels using a supercritical drying process - resulting in a composition of almost 99-percent air - aerogels are the world s lightest solid (among 15 other titles they hold in the Guinness World Records), can float indefinitely on water if treated to be

  7. Apparent Thermal Conductivity Of Multilayer Insulation

    Science.gov (United States)

    Mcintosh, Glen E.

    1995-01-01

    Mathematical model of apparent or effective thermal conductivity between two successive layers of multilayer thermal insulation (MLI) offers potential for optimizing performance of insulation. One gains understanding of how each physical mechanism contributes to overall flow of heat through MLI blanket. Model helps analyze engineering tradeoffs among such parameters as number of layers, thicknesses of gaps between layers, types of spacers placed in gaps, weight, overall thickness, and effects of foregoing on apparent thermal conductivity through blanket.

  8. Sprayable Thermal Insulation for Cryogenic Tanks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation addressed in this proposal is Sprayable Thermal Insulation for Cryogenic Tanks, or STICT. This novel system could be applied in either an automated or...

  9. 14 CFR 25.856 - Thermal/Acoustic insulation materials.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Thermal/Acoustic insulation materials. 25....856 Thermal/Acoustic insulation materials. (a) Thermal/acoustic insulation material installed in the... requirement does not apply to thermal/acoustic insulation installations that the FAA finds would not...

  10. Thermal Performance Testing of Cryogenic Insulation Systems

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stan D.; Scholtens, Brekke E.

    2007-01-01

    Efficient methods for characterizing thermal performance of materials under cryogenic and vacuum conditions have been developed. These methods provide thermal conductivity data on materials under actual-use conditions and are complementary to established methods. The actual-use environment of full temperature difference in combination with vacuum-pressure is essential for understanding insulation system performance. Test articles include solids, foams, powders, layered blankets, composite panels, and other materials. Test methodology and apparatus design for several insulation test cryostats are discussed. The measurement principle is liquid nitrogen boil-off calorimetry. Heat flux capability ranges from approximately 0.5 to 500 watts per square meter; corresponding apparent thermal conductivity values range from below 0.01 up to about 60 mW/m- K. Example data for different insulation materials are also presented. Upon further standardization work, these patented insulation test cryostats can be available to industry for a wide range of practical applications.

  11. Evaluation of thermal insulation materials

    Science.gov (United States)

    Wilbers, O. J.; Conti, J. C.; Mcgee, J. V.; Mcpherson, J. I.

    1973-01-01

    Data was obtained on silicone-bonded fiberglass, isocyanurate foam, and two dozen other insulators. Materials were selected to withstand heat sterilization, outer space, and the Martian atmosphere. Significant environmental parameters were vibration, landing shock, and launch venting.

  12. Aerogels for Thermal Insulation of Thermoelectric Devices

    Science.gov (United States)

    Sakamoto, Jeffrey; Fleurial, Jean-Pierre; Snyder, Jeffrey; Jones, Steven; Caillat, Thierry

    2006-01-01

    Silica aerogels have been shown to be attractive for use as thermal-insulation materials for thermoelectric devices. It is desirable to thermally insulate the legs of thermoelectric devices to suppress lateral heat leaks that degrade thermal efficiency. Aerogels offer not only high thermal- insulation effectiveness, but also a combination of other properties that are especially advantageous in thermoelectric- device applications. Aerogels are synthesized by means of sol-gel chemistry, which is ideal for casting insulation into place. As the scale of the devices to be insulated decreases, the castability from liquid solutions becomes increasingly advantageous: By virtue of castability, aerogel insulation can be made to encapsulate devices having any size from macroscopic down to nanoscopic and possibly having complex, three-dimensional shapes. Castable aerogels can permeate voids having characteristic dimensions as small as nanometers. Hence, practically all the void space surrounding the legs of thermoelectric devices could be filled with aerogel insulation, making the insulation highly effective. Because aerogels have the lowest densities of any known solid materials, they would add very little mass to the encapsulated devices. The thermal-conductivity values of aerogels are among the lowest reported for any material, even after taking account of the contributions of convection and radiation (in addition to true thermal conduction) to overall effective thermal conductivities. Even in ambient air, the contribution of convection to effective overall thermal conductivity of an aerogel is extremely low because of the highly tortuous nature of the flow paths through the porous aerogel structure. For applications that involve operating temperatures high enough to give rise to significant amounts of infrared radiation, opacifiers could be added to aerogels to reduce the radiative contributions to overall effective thermal conductivities. One example of an opacifier is

  13. Low-Density, Sprayable, Thermal Insulation

    Science.gov (United States)

    Mclemore, James P.; Norton, William E.; Lambert, Joe D.; Simpson, William G.; Echols, Sherman; Sharpe, Max H.; Hill, William E.

    1989-01-01

    Improved formulation prevents cracks. Low-density, thermally insulating material applied by spraying it onto surface to be protected. Material, called "MSA-2" improved version of similar material called "MSA-1". Useful as sprayed, lightweight insulation to cover large areas in terrestrial applications in which manual attachment too slow or impractical. Formulated to be more flexible and to prevent coats as thick as 1/2 in. from developing stress cracks as they cure.

  14. Relationship between clothing ventilation and thermal insulation.

    Science.gov (United States)

    Bouskill, L M; Havenith, G; Kuklane, K; Parsons, K C; Withey, W R

    2002-01-01

    Air layers trapped within a clothing microenvironment contribute to the thermal insulation afforded by the ensemble. Any exchange of air between the external environment and these trapped air layers results in a change in the ensemble's thermal insulation and water vapor resistance characteristics. These effects are seldom taken into account when considering the effects of clothing on human heat balance, the thermal characteristics usually being restricted to intrinsic insulation and intrinsic evaporative resistance measurements on static manikins. Environmental assessments based on these measurements alone may therefore lead to under-(or over-) estimation of thermal stress of the worker. The aim of this study was to quantify the relationship between clothing ventilation and thermal insulation properties. A one-layer, air-impermeable ensemble and a three-layer, air-permeable ensemble were tested using an articulated, thermal manikin in a controlled climate chamber (ta = tr = 10 degrees C, PaH2O = 0.73 kPa). The manikin, which was designed for thermal insulation measurements, was also equipped with a system to determine clothing ventilation. Baseline measurements of clothing ventilation (VT) and thermal insulation (total clothing insulation: I(T)--measured, intrinsic insulation: Icl--calculated) were made of the clothing with the manikin standing stationary in still air conditions. Increased clothing ventilation was induced when the manikin "walked" (walking speeds of 0.37 m/sec and 0.77 m/sec) and by increasing the environmental air speed (Va = 1.0 m/sec). These increases in VT reduced Icl, this being ascribed to the increased heat transfer from the manikin skin surface to the cooler external environment due to the exchange of air between the clothing microenvironment and the external environment. Measured air exchanges were shown to have a potential heat exchange capacity of up to 17 and 161 W/m2 for the one- and three-layer ensembles, respectively, emphasizing

  15. MAS Bulletin. Microtherm Thermal Insulation

    Science.gov (United States)

    1989-03-03

    nonstandard diameters and special wall thicknesses can be produced to order. The principal constituents of Microtherm MPS are microporous silicas ...by a cladding system. Most purpose-made 0 0: pire insulation coatings of resin, bitumen , etc., can be applied to Microtherm MPS, but for full

  16. Nuclear reactor vessel fuel thermal insulating barrier

    Science.gov (United States)

    Keegan, C. Patrick; Scobel, James H.; Wright, Richard F.

    2013-03-19

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel that has a hemispherical lower section that increases in volume from the center line of the reactor to the outer extent of the diameter of the thermal insulating barrier and smoothly transitions up the side walls of the vessel. The space between the thermal insulating harrier and the reactor vessel forms a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive inlet valve for the cooling water includes a buoyant door that is normally maintained sealed under its own weight and floats open when the cavity is Hooded. Passively opening steam vents are also provided.

  17. Soup Cooking by Thermal Insulation Method

    OpenAIRE

    佐藤, 辰江; 根本, 勢子; サトウ, タツエ; ネモト, セイコ; TATSUE, SATO; Seiko, Nemoto

    1992-01-01

    In order to examine the thermal insulation method of soup cooking, we cooked two kinds of soup. The soup cooked by thermal insulation method was compared with the soup cooked by standard boiling method. ln sensory test, it was more aromatic and palatable than the soup by boiling, and some panels commented that it was rather mild. The measured values of pH, specific gravity, acidity and amount of dry weight of souble solids, total-N, formal-N of the soup cooked by the two methods mentioned abo...

  18. Multilayer Impregnated Fibrous Thermal Insulation Tiles

    Science.gov (United States)

    Tran, Huy K.; Rasky, Daniel J.; Szalai, Christine e.; Hsu, Ming-ta; Carroll, Joseph A.

    2007-01-01

    The term "secondary polymer layered impregnated tile" ("SPLIT") denotes a type of ablative composite-material thermal- insulation tiles having engineered, spatially non-uniform compositions. The term "secondary" refers to the fact that each tile contains at least two polymer layers wherein endothermic reactions absorb considerable amounts of heat, thereby helping to prevent overheating of an underlying structure. These tiles were invented to afford lighter-weight alternatives to the reusable thermal-insulation materials heretofore variously used or considered for use in protecting the space shuttles and other spacecraft from intense atmospheric-entry heating.

  19. Perioperative thermal insulation: minimal clinically important differences?

    Science.gov (United States)

    Bräuer, A; Perl, T; Uyanik, Z; English, M J M; Weyland, W; Braun, U

    2004-06-01

    Reduction of heat losses from the skin by thermal insulation is used to avoid perioperative hypothermia. However, there is little information about the physical properties of various insulating materials used in the operating room. The following insulation materials were tested using a validated manikin: cotton surgical drape tested in two and four layers; Allegiance drape; 3M Steri-Drape; metallized plastic sheet; Thermadrape Barkey thermcare 1 tested in one and two layers; hospital duvet tested in one and two layers. Heat loss from the surface of the manikin can be described as: Q(*);= h.DeltaT.A where Q(*); is heat flux, h is the heat exchange coefficient, DeltaT is the temperature gradient between the environment and surface and A is the area covered. The heat flux per unit area (Q(*); A(-1)) and surface temperature were measured with nine calibrated heat-flux transducers. The environmental temperature was measured using a thermoanemometer. DeltaT was varied and h was determined by linear regression analysis as the slope of DeltaT vs Qdot; A(-1). The reciprocal of h defines the insulation. The insulation value of air was 0.61 Clo. The insulation values of the materials varied between 0.17 Clo (two layers of cotton surgical drapes) to 2.79 Clo (two layers of hospital duvet). There are relevant differences between various insulating materials. The best commercially available material designed for use in the operating room (Barkey thermcare 1) can reduce heat loss from the covered area by 45% when used in two layers. Given the range of insulating materials available for outdoor activities, significant improvement in insulation of patients in the operating room is both possible and desirable.

  20. Thermal insulation for preventing inadvertent perioperative hypothermia.

    Science.gov (United States)

    Alderson, Phil; Campbell, Gillian; Smith, Andrew F; Warttig, Sheryl; Nicholson, Amanda; Lewis, Sharon R

    2014-06-04

    Inadvertent perioperative hypothermia occurs because of interference with normal temperature regulation by anaesthetic drugs and exposure of skin for prolonged periods. A number of different interventions have been proposed to maintain body temperature by reducing heat loss. Thermal insulation, such as extra layers of insulating material or reflective blankets, should reduce heat loss through convection and radiation and potentially help avoid hypothermia. To assess the effects of pre- or intraoperative thermal insulation, or both, in preventing perioperative hypothermia and its complications during surgery in adults. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 2), MEDLINE, OvidSP (1956 to 4 February 2014), EMBASE, OvidSP (1982 to 4 February 2014), ISI Web of Science (1950 to 4 February 2014), and CINAHL, EBSCOhost (1980 to 4 February 2014), and reference lists of articles. We also searched Current Controlled Trials and ClinicalTrials.gov. Randomized controlled trials of thermal insulation compared to standard care or other interventions aiming to maintain normothermia. Two authors extracted data and assessed risk of bias for each included study, with a third author checking details. We contacted some authors to ask for additional details. We only collected adverse events if reported in the trials. We included 22 trials, with 16 trials providing data for some analyses. The trials varied widely in the type of patients and operations, the timing and measurement of temperature, and particularly in the types of co-interventions used. The risk of bias was largely unclear, but with a high risk of performance bias in most studies and a low risk of attrition bias. The largest comparison of extra insulation versus standard care had five trials with 353 patients at the end of surgery and showed a weighted mean difference (WMD) of 0.12 ºC (95% CI -0.07 to 0.31; low quality evidence). Comparing extra insulation

  1. Aerogel Beads as Cryogenic Thermal Insulation System

    Science.gov (United States)

    Fesmire, J. E.; Augustynowicz, S. D.; Rouanet, S.; Thompson, Karen (Technical Monitor)

    2001-01-01

    An investigation of the use of aerogel beads as thermal insulation for cryogenic applications was conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Steady-state liquid nitrogen boiloff methods were used to characterize the thermal performance of aerogel beads in comparison with conventional insulation products such as perlite powder and multilayer insulation (MLI). Aerogel beads produced by Cabot Corporation have a bulk density below 100 kilograms per cubic meter (kg/cubic m) and a mean particle diameter of 1 millimeter (mm). The apparent thermal conductivity values of the bulk material have been determined under steady-state conditions at boundary temperatures of approximately 293 and 77 kelvin (K) and at various cold vacuum pressures (CVP). Vacuum levels ranged from 10(exp -5) torr to 760 torr. All test articles were made in a cylindrical configuration with a typical insulation thickness of 25 mm. Temperature profiles through the thickness of the test specimens were also measured. The results showed the performance of the aerogel beads was significantly better than the conventional materials in both soft-vacuum (1 to 10 torr) and no-vacuum (760 torr) ranges. Opacified aerogel beads performed better than perlite powder under high-vacuum conditions. Further studies for material optimization and system application are in progress.

  2. Thermal Insulation System for Large Flame Buckets

    Science.gov (United States)

    Callens, E. Eugene, Jr.; Gamblin, Tonya Pleshette

    1996-01-01

    The objective of this study is to investigate the use of thermal protection coatings, single tiles, and layered insulation systems to protect the walls of the flame buckets used in the testing of the Space Shuttle Main Engine, while reducing the cost and maintenance of the system. The physical behavior is modeled by a plane wall boundary value problem with a convective frontface condition and a backface condition designed to provide higher heat rates through the material.

  3. Building ceramics with improved thermal insulation parameters

    Directory of Open Access Journals (Sweden)

    Rzepa Karol

    2016-01-01

    Full Text Available One of the most important performance characteristics of masonry units is their high thermal insulation. There are many different ways to improve this parameter, however the most popular methods in case of ceramic masonry units are: addition of pore-creating raw materials and application of proper hole pattern. This study was an attempt to improve thermal insulation of ceramics by applying thermal insulation additives. Perlite dust created as a subgrain from expansion of perlite rock was used. Perlite subgrain is not very popular among consumers, that’s why it’s subjected to granulation to obtain coarse grain. The authors presented concept of direct application of perlite dust for the production of building ceramics with improved thermal insulation. Fineness of this additive is asset for molding of ceramic materials from plastic masses. Based on the results it was found that about 70% perlite by volume can be added to obtain material with a coefficient of heat conductivity of 0,37 W/mK. Higher content of this additive in ceramic mass causes deterioration of its rheological properties. Mass loses its plasticity, it tears up and formed green bodies are susceptible to deformation. During sintering perlite takes an active part in compaction process. Higher sintering dynamics is caused by: high content of alkali oxides in perlite and glass nature of perlite. Alkali oxides generate creation of liquid phase which intensifies mass compaction processes. Active role of perlite in sintering process causes good connection of its grains with clay groundwork which is important factor for mechanical parameters of ceramic materials. It was also noted that addition of perlite above 40% by volume of mass effectively neutralized negative effect of efflorescence in ceramic materials.

  4. Smoldering combustion hazards of thermal insulation materials

    Energy Technology Data Exchange (ETDEWEB)

    Ohlemiller, T.J.; Rogers, F.E.

    1980-07-01

    Work on the smolder ignitability in cellulosic insulation and on thermal analytical characterization of the oxidation of this material is presented. Thermal analysis (TGA and DSC) shows that both retarded and unretarded cellulosic insulation oxidizes in two overall stages, both of which are exothermic. The second stage (oxidation of the char left as a residue of the first stage) is much more energetic on a unit mass basis than the first. However, kinetics and a sufficient exothermicity make the first stage responsible for ignition in most realistic circumstances. Existing smolder retardants such as boric acid have their major effect on the kinetics of the second oxidation stage and thus produce only a rather small (20/sup 0/C) increase in smolder ignition temperature. Several simplified analogs of attic insulations have been tested to determine the variability of minimum smolder ignition temperature. These employed planar or tubular constant temperature heat sources in a thermal environment quite similar to a realistic attic application. Go/no-go tests provided the borderline (minimum) ignition temperature for each configuration. The wide range (150/sup 0/C) of minimum ignition temperatures confirmed the predominant dependence of smolder ignition on heat flow geometry. Other factors (bulk density, retardants) produced much less effect on ignitability.

  5. Overview of thermal conductivity models of anisotropic thermal insulation materials

    Science.gov (United States)

    Skurikhin, A. V.; Kostanovsky, A. V.

    2017-11-01

    Currently, the most of existing materials and substances under elaboration are anisotropic. It makes certain difficulties in the study of heat transfer process. Thermal conductivity of the materials can be characterized by tensor of the second order. Also, the parallelism between the temperature gradient vector and the density of heat flow vector is violated in anisotropic thermal insulation materials (TIM). One of the most famous TIM is a family of integrated thermal insulation refractory material («ITIRM»). The main component ensuring its properties is the «inflated» vermiculite. Natural mineral vermiculite is ground into powder state, fired by gas burner for dehydration, and its precipitate is then compressed. The key feature of thus treated batch of vermiculite is a package structure. The properties of the material lead to a slow heating of manufactured products due to low absorption and high radiation reflection. The maximum of reflection function is referred to infrared spectral region. A review of current models of heat propagation in anisotropic thermal insulation materials is carried out, as well as analysis of their thermal and optical properties. A theoretical model, which allows to determine the heat conductivity «ITIRM», can be useful in the study of thermal characteristics such as specific heat capacity, temperature conductivity, and others. Materials as «ITIRM» can be used in the metallurgy industry, thermal energy and nuclear power-engineering.

  6. Ceramic-Fibrous-Insulation Thermal-Protection System

    Science.gov (United States)

    Leiser, Daniel; Churchward, Rex; Katvala, Victor; Stewart, David; Balter, Aliza

    1992-01-01

    New composite thermal-protection system developed in which glass-ceramic impregnated into surface of fibrous insulation. Called TUFI for toughened unipiece fibrous insulation developed as replacement for tiles with reaction-cured-glass (RCG) coating. Impregnation of glass-ceramic results in thermal protection system with insulating properties comparable to existing system but with 20 to 100 times more resistance to impact.

  7. Determination of the Thermal Resistance of Pipe Insulation Material from Thermal Conductivity of Flat Insulation Products

    OpenAIRE

    Koenen, Alain; Marquis, Damien M.

    2015-01-01

    New European product standards now include a mandatory requirement for manufacturers to declare the temperature-dependent thermal conductivity for each insulation used in building equipments and industrial installations. For pipe insulation systems, the measurement is usually performed by a standard pipe test method, in which the value on a large temperature range is integrated to reduce temperature range and improve temperature measurement control. The alternative proposed in this article co...

  8. Evaluation of Fire Test Methods for Aircraft Thermal Acoustical Insulation

    Science.gov (United States)

    1997-09-01

    This report presents the results of laboratory round robin flammability testing performed on thermal acoustical insulation blankets and the films used as insulation coverings. This work was requested by the aircraft industry as a result of actual inc...

  9. Verification of the thermal insulation properties and determination the optimal position of the reflective thermal insulation layer in the wood based envelope

    National Research Council Canada - National Science Library

    Martin Labovský; Martin Lopušniak

    2016-01-01

    To achieve thinner wood based envelope is necessary look for an alternative thermal insulation material, which will have the best possible thermal insulation properties while maintaining affordability...

  10. Advances in Thermal Insulation. Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Thorsell, Thomas

    2012-07-01

    We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment. Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60 % if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hydrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The

  11. System for Testing Thermal Insulation of Pipes

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stanislaw D.; Nagy, Zoltan F.

    2003-01-01

    An apparatus and method have been developed for measuring the rates of leakage of heat into pipes carrying liquids, the purpose of the measurements being to quantify the thermal performance of the insulation system. The apparatus is designed primarily for testing pipes used to carry cryogenic liquids, but can also be used for measuring the thermal performance of other insulated pipes or piping systems. The basic measurement principle is straightforward: The outer surface of the pipe insulation is maintained at a fixed warmer temperature. The interior of the pipe is maintained in a narrow fixed lower-temperature range by means of a regular liquid (e.g., water) that is pumped through the pipe at a known flow rate or a cryogenic liquid (e.g., nitrogen) that is saturated at atmospheric pressure and replenished until steady-state conditions are achieved. In the case of water or another liquid pumped through, the inlet and outlet temperatures are measured and heat-leak power is calculated as the mass flow rate of the liquid multiplied by the specific heat of the liquid multiplied by the inlet-to-outlet temperature rise of the liquid. In the case of liquid nitrogen or another low-temperature boiling liquid, the heat-leak power is calculated as the rate of boil-off multiplied by the latent heat of vaporization of the liquid. Then the thermal-insulation performance of the pipe system can be calculated as a function of the measured heat-leak power, the inner and outer boundary temperatures, and the dimensions of the pipe. The apparatus can test as many as three pipes simultaneously. The pipes can have inner diameters up to .15 cm and outer diameters up to .20 cm. The lengths of the pipes may vary; typical lengths are of the order of 18 m. Two thermal guard boxes . one for each end of the pipe(s) under test . are used to make the inlet and outlet fluid connections to the pipe(s) (see figure). The connections include bellows that accommodate thermal expansion and contraction

  12. Analysis and Experimental on Aircraft Insulation Thermal Bridge Effect

    Directory of Open Access Journals (Sweden)

    XIA Tian

    2017-06-01

    Full Text Available Two kinds of typical aircraft insulation structures were designed for the heat bridge in the metal ribs of aircraft insulation structures. In order to study the influence of heat bridge effect on thermal insulation performance, each configuration was analyzed by the transient heat transfer FEA, check point temperature was obtained in the hot surface temperature of 100 ℃, 200 ℃, 300 ℃, 424 ℃ respectively, and the validity of FEA was proved by insulation performance experiment. The result showed that the thermal bridge has a great influence to the insulation performance of insulation structure, and the thermal bridge influence should be considered adequately when the insulation structure designed. Additionally, the blocking method for thermal bridge is also put forward.

  13. Better Thermal Insulation in Solar-Array Laminators

    Science.gov (United States)

    Burger, D. R.; Knox, J. F.

    1984-01-01

    Glass marbles improve temperature control. Modified vacuum laminator for photovoltaic solar arrays includes thermal insulation made of conventional glass marbles. Marbles serve as insulation for temperature control of lamination process at cure temperatures as high as 350 degrees F. Used to replace original insulation made of asbestos cement.

  14. Treating Fibrous Insulation to Reduce Thermal Conductivity

    Science.gov (United States)

    Zinn, Alfred; Tarkanian, Ryan

    2009-01-01

    A chemical treatment reduces the convective and radiative contributions to the effective thermal conductivity of porous fibrous thermal-insulation tile. The net effect of the treatment is to coat the surfaces of fibers with a mixture of transition-metal oxides (TMOs) without filling the pores. The TMO coats reduce the cross-sectional areas available for convection while absorbing and scattering thermal radiation in the pores, thereby rendering the tile largely opaque to thermal radiation. The treatment involves a sol-gel process: A solution containing a mixture of transition-metal-oxide-precursor salts plus a gelling agent (e.g., tetraethylorthosilicate) is partially cured, then, before it visibly gels, is used to impregnate the tile. The solution in the tile is gelled, then dried, and then the tile is fired to convert the precursor salts to the desired mixed TMO phases. The amounts of the various TMOs ultimately incorporated into the tile can be tailored via the concentrations of salts in the solution, and the impregnation depth can be tailored via the viscosity of the solution and/or the volume of the solution relative to that of the tile. The amounts of the TMOs determine the absorption and scattering spectra.

  15. Prospect of Thermal Insulation by Silica Aerogel: A Brief Review

    Science.gov (United States)

    Hasan, Mohammed Adnan; Sangashetty, Rashmi; Esther, A. Carmel Mary; Patil, Sharanabasappa B.; Sherikar, Baburao N.; Dey, Arjun

    2017-10-01

    Silica aerogel is a unique ultra light weight nano porous material which offers superior thermal insulation property as compared to the conventional thermal insulating materials. It can be applied not only for ground and aerospace applications but also in low and high temperatures and pressure regimes. Aerogel granules and monolith are synthesized by the sol-gel route while aerogel based composites are fabricated by the reinforcement of fibers, particle and opacifiers. Due to the characteristic brittleness (i.e., poor mechanical properties) of monolith or bulk aerogel, it is restricted in several applications. To improve the mechanical integrity and flexibility, usually different fibers are reinforced with aerogel and hence it can be used as flexible thermal insulation blankets. Further, to achieve effective thermal insulation behaviour particularly at high temperature, often opacifiers are doped with silica aerogel. In the present brief review, the prospects of bulk aerogel and aerogel based composites are discussed for the application of thermal insulation and thermal stability.

  16. Preparation of a Novel Water-based Acrylic Multi-Thermal Insulation Coating

    OpenAIRE

    Xiufang YE; Dongchu CHEN; Chang, Menglei; Youtian MO; Wang, Qingxiang

    2017-01-01

    To efficiently improve the thermal insulation effect of coatings, a novel water-based acrylic multi-thermal insulation coating (multi-WATIC) combined with thermal obstruction, echo, and radiation was prepared. The category and ratio of thermal insulation functional fillers are crucial. First, water-based acrylic thermal insulation coating (WATIC) with single thermal insulation functional fillers was prepared, and the thermal insulation property tests were done. Thereafter, a novel multi-WATIC...

  17. Effects of thermal insulation on electrical connections and outlet boxes

    Science.gov (United States)

    Beausoliel, R. W.; Clifton, J. R.; Meese, W. J.

    1981-04-01

    When residential walls are retrofitted with foamed-in urea formaldehyde or blown-in cellulose thermal insulations, the insulation may enter electrical outlet and switch boxes. The effects of these thermal insulations on the durability of electrical components were studied. These studies were carried out at 44, 75, and 96 percent relative humidities with test periods between one and twelve months. Laboratory test methods were developed and tests performed to determine the electrical and corrosive effects of urea formaldehyde and cellulose thermal insulation contained in electrical outlet and switch boxes.

  18. Methods of Testing Thermal Insulation and Associated Test Apparatus

    Science.gov (United States)

    2004-01-01

    The system and method for testing thermal insulation uses a cryostatic insulation tester having a vacuum chamber and a cold mass including a test chamber and upper and lower guard chambers adjacent thereto. The thermal insulation is positioned within the vacuum chamber and adjacent the cold mass. Cryogenic liquid is supplied to the test chamber, upper guard and lower guard to create a first gas layer in an upper portion of the lower guard chamber and a second gas layer in an upper portion of the test chamber. Temperature are sensed within the vacuum chamber to test the thermal insulation.

  19. Thermal insulation of steep roofs. Heat insulating effects of different systems; Daemmung in Steildaechern. Die waermeschutztechnischen Wirkung unterschiedlicher Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, Gerd [Technische Univ. Muenchen (Germany). Lehrstuhl Bauphysik; Fraunhofer-Institut fuer Bauphysik, Stuttgart, Holzkirchen, Kassel (Germany); Schade, Almuth; Sinnesbichler, Herbert [Fraunhofer-Institut fuer Bauphysik, Holzkirchen (Germany). Arbeitsgruppe Fassadenkonzepte

    2009-06-29

    For thermal insulation of steep roofs, so-called infrared reflecting thermal insulation materials are now available in France and also in Germany in addition to traditional thermal insulation systems. The insulating effect of these systems results primarily from the IR-reflecting surface of foils spaced at short intervals. For a comparison of the two thermal insulation systems, the Fraunhofer Institute of Constructional Physics of Holzkirchen carried out field tests and analyzed them. (orig.)

  20. Verification of the thermal insulation properties and determination the optimal position of the reflective thermal insulation layer in the wood based envelope

    Directory of Open Access Journals (Sweden)

    Labovský Martin

    2016-06-01

    Full Text Available To achieve thinner wood based envelope is necessary look for an alternative thermal insulation material, which will have the best possible thermal insulation properties while maintaining affordability. One such material is also reflective thermal insulation layer, but it is necessary to verify the thermal insulation properties and determine the optimal position in the wood based envelope.

  1. THERMAL INSULATION EFFECTS ON ENERGY EFFICIENCY OF BUILDING STRUCTURES

    OpenAIRE

    M. Cvetkovska; Knezevic, M.; Rogac, M.

    2012-01-01

    This paper presents the use of Finite Element Method for heat transfer analysis. Connections wall-beam-floor structures with different positions of the thermal insulation have been analyzed and conclusions about energy efficiency and energy loss are made. Keywords: heat transfer, numerical analysis, finite elements, thermal insulation, energy efficiency.

  2. The Wick-Concept for Thermal Insulation of Cold Piping

    DEFF Research Database (Denmark)

    Koverdynsky, Vit; Korsgaard, Vagn; Rode, Carsten

    2006-01-01

    The wick-concept for thermal insulation of cold piping is based on capillary suction of a fiber fabric to remove excess water from the pipe surface by transporting it to the outer surface of the insulation. From the surface of the insulation jacket, the water will evaporate to the ambient air....... This will prevent long-term accumulation of moisture in the insulation material. The wick keeps the hydrophobic insulation dry, allowing it to maintain its thermal performance. The liquid moisture is kept only in the wick fabric. This article presents the principle of operation of cold pipe insulation using...... that the variations of these types of insulation systems work for pipes with temperature above 0C and for ambient conditions within common ranges for industrial applications....

  3. Сombined Thermal Insulating Module of Mounted Vented Facades

    Directory of Open Access Journals (Sweden)

    Ryabukhina Svetlana

    2016-01-01

    Full Text Available In order to define an optimum type of mounted vented facades among the existing ones, comparative analysis of two façade modules has been conducted. The first module type is a widespread standard module of hinged vented facade and the second type is less applicable combined thermal insulating module. Those two technologies were compared thermal engineering and energy efficiency parameters. It was defined that the application of a thermal insulating module with combined insulation system improves thermal engineering parameters of the building as well as leads to a substantial savings. This article exposes innovative materials and structure of vented facades which can be applied in modern construction.

  4. Review on thermal insulation performance in various type of concrete

    Science.gov (United States)

    Shahedan, Noor Fifinatasha; Abdullah, Mohd Mustafa Al Bakri; Mahmed, Norsuria; Kusbiantoro, Andri; Binhussain, Mohammed; Zailan, Siti Norsaffirah

    2017-04-01

    Thermal insulation concrete building plays an important role in environment sustainability especially energy saving buildings. Buildings are one of the largest consumers of energy worldwide. Therefore, significant energy saving can be realized by buildings with proper materials, design and operation. Thermal insulation systems are nowadays mostly applied for such building envelopes where the materials of load bearing structure such as concrete do not have a substantial thermal insulation capability. Thermal insulation in concrete are materials or combinations of materials that are used to provide resistance to heat flow, should have low conductivity for building application in order to represence of a temperature gradient, has an important effect on the heat exchange between the building interior and the ambiance. The aim of this paper is to review the thermal properties include thermal conductivity and specific heat on various types of concrete.

  5. Thermal insulation testing method and apparatus

    Science.gov (United States)

    Fesmire, James E. (Inventor); Augustynowicz, Stanislaw D. (Inventor)

    2004-01-01

    A test apparatus and method of its use for evaluating various performance aspects of a test specimen is disclosed. A chamber within a housing contains a cold mass tank with a contact surface in contact with a first surface of a test specimen. The first surface of the test specimen is spaced from the second surface of the test specimen by a thickness. The second surface of the test specimen is maintained at a desired warm temperature. The first surface is maintained at a constant temperature by a liquid disposed within the cold mass tank. A boil-off flow rate of the gas is monitored and provided to a processor along with the temperature of the first and second surfaces of the test specimen. The processor calculates thermal insulation values of the test specimen including comparative values for heat flux and apparent thermal conductivity (k-value). The test specimen may be placed in any vacuum pressure level ranging from about 0.01 millitorr to 1,000,000 millitorr with different residual gases as desired. The test specimen may be placed under a mechanical load with the cold mass tank and another factors may be imposed upon the test specimen so as to simulate the actual use conditions.

  6. Integrated Thermal Insulation System for Spacecraft

    Science.gov (United States)

    Kolodziej, Paul (Inventor); Bull, Jeff (Inventor); Kowalski, Thomas (Inventor); Switzer, Matthew (Inventor)

    1998-01-01

    An integrated thermal protection system (TPS) for a spacecraft includes a grid that is bonded to skin of the spacecraft, e.g., to support the structural loads of the spacecraft. A plurality of thermally insulative, relatively large panels are positioned on the grid to cover the skin of the spacecraft to which the grid has been bonded. Each panel includes a rounded front edge and a front flange depending downwardly from the front edge. Also, each panel includes a rear edge formed with a rounded socket for receiving the rounded front edge of another panel therein, and a respective rear flange depends downwardly from each rear edge. Pins are formed on the front flanges, and pin receptacles are formed on the rear flanges, such that the pins of a panel mechanically interlock with the receptacles of the immediately forward panel. To reduce the transfer to the skin of heat which happens to leak through the panels to the grid, the grid includes stringers that are chair-shaped in cross-section.

  7. Environmental safety providing during heat insulation works and using thermal insulation materials

    Directory of Open Access Journals (Sweden)

    Velichko Evgeny

    2017-01-01

    Full Text Available This article considers the negative effect of thermal insulating materials and products on human health and environment pollution, particularly in terms of the composition of environmentally hazardous construction products. The authors have analyzed the complex measures for providing ecological safety, sanitary and epidemiological requirements, rules and regulations both during thermal insulation works and throughout the following operation of buildings and premises. The article suggests the protective and preventive measures to reduce and eliminate the negative impact of the proceeding of thermal insulation works on the natural environment and on human health.

  8. Thermal-Insulation Properties of Multilayer Textile Packages

    Directory of Open Access Journals (Sweden)

    Matusiak Małgorzata

    2014-12-01

    Full Text Available Thermal-insulation properties of textile materials play a significant role in material engineering of protective clothing. Thermal-insulation properties are very important from the point of view of thermal comfort of the clothing user as well as the protective efficiency against low or high temperature. Thermal protective clothing usually is a multilayer construction. Its thermal insulation is a resultant of a number of layers and their order, as well as the thermalinsulation properties of a single textile material creating particular layers. The aim of the presented work was to investigate the relationships between the thermal-insulation properties of single materials and multilayer textile packages composed of these materials. Measurement of the thermal-insulation properties of single and multilayer textile materials has been performed with the Alambeta. The following properties have been investigated: thermal conductivity, resistance and absorptivity. Investigated textile packages were composed of two, three and four layers made of woven and knitted fabrics, as well as nonwovens. On the basis of the obtained results an analysis has been carried out in order to assess the dependency of the resultant values of the thermal-insulation properties of multilayer packages on the appropriate values of particular components.

  9. High performance thermal insulation systems - HLWD; Hochleistungs-Waermedaemmung HLWD

    Energy Technology Data Exchange (ETDEWEB)

    Eicher, H.; Erb, M. [Eicher und Pauli AG, Liestal (Switzerland); Binz, A.; Moosmann, A. [Fachhochschule beider Basel, Institut fuer Energie, Muttenz (Switzerland)

    2000-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) by the research program concerning the efficient use of energy in buildings takes a look at high-performance thermal insulation systems (HLWD). Work done on three applications - internal insulation used in the refurbishment of buildings, insulation of hot-water storage tanks and outside doors - is reported on. Economic feasibility is discussed and a number of demonstration projects are reported on. Apart from the above mentioned, the insulation of a terrace, the insulation of a roller-blind housing and the insulation of a deep-freeze cubicle are reviewed. The construction of vacuum insulation panels (VIP) and their manufacture are looked at. Economic aspects are looked at and the use of VIP in practice is discussed.

  10. Estimating Clothing Thermal Insulation Using an Infrared Camera

    OpenAIRE

    Jeong-Hoon Lee; Young-Keun Kim; Kyung-Soo Kim; Soohyun Kim

    2016-01-01

    In this paper, a novel algorithm for estimating clothing insulation is proposed to assess thermal comfort, based on the non-contact and real-time measurements of the face and clothing temperatures by an infrared camera. The proposed method can accurately measure the clothing insulation of various garments under different clothing fit and sitting postures. The proposed estimation method is investigated to be effective to measure its clothing insulation significantly in different seasonal cloth...

  11. Energy Consumption of Insulated Material Using Thermal Effect Analysis

    OpenAIRE

    Fadzil M. A.; Norliyati M. A.; Hilmi M. A.; Ridzuan A. R.; Wan Ibrahim M. H.; Assrul R. Z.

    2017-01-01

    Wall is one of the structures elements that resist direct heat from the atmosphere. Modification on several structures is relevance to reduce filtrate thermal movement on wall. Insulation material seems to be suitable to be implemented since its purpose meets the heat resistance requirement. Insulation material applied as to generate positive impact in energy saving through reduction in total building energy consumption. Fiberglass is one of the insulation materials that can be used to insula...

  12. Composite flexible insulation for thermal protection of space vehicles

    Science.gov (United States)

    Kourtides, Demetrius A.; Tran, Huy K.; Chiu, S. Amanda

    1992-01-01

    A composite flexible blanket insulation (CFBI) system considered for use as a thermal protection system for space vehicles is described. This flexible composite insulation system consists of an outer layer of silicon carbide fabric, followed by alumina mat insulation, and alternating layers of aluminized polyimide film and aluminoborosilicate scrim fabric. A potential application of this composite insulation would be as a thermal protection system for the aerobrake of the Aeroassist Space Transfer Vehicle (ASTV). It would also apply to other space vehicles subject to high convective and radiative heating during atmospheric entry. The thermal performance of this composite insulation as exposed to a simulated atmospheric entry environment in a plasma arc test facility is described. Other thermophysical properties which affect the thermal response of this system are also described. Analytical modeling describing the thermal performance of this composite insulation is included. It shows that this composite insulation is effective as a thermal protection system at total heating rates up to 30.6 W/sq cm.

  13. Electrostatic Separation Of Layers In Thermal Insulation

    Science.gov (United States)

    Bhandari, Pradeep

    1995-01-01

    Layers in multilayer insulation charged to keep them separated by electrostatic repulsion, eliminating need for spacer nets. Removal of spacer nets reduces conduction of heat between layers. Insulation in question type used to slow leakage of heat into Dewar flasks containing liquid helium. Proposal originally applied to insulation in cryogenic cooling subsystems of infrared-detector systems in outer space, also appears applicable to small panels of insulation for terrestrial cryogenic equipment, provided layers contained in evacuated spaces and weight of each layer small fraction of electrostatic force upon it.

  14. Thermal transmittance of a cellulose loose-fill insulation material

    Energy Technology Data Exchange (ETDEWEB)

    Nicolajsen, A. [Danish Building and Urban Research, Hoersholm (Denmark). Department of Building Technology and Productivity

    2005-07-15

    The thermal performance of cellulose insulation material was investigated and compared with the thermal performance of stone wool batts. The moisture content in selected facade elements insulated with cellulose loose-fill insulation material and stone wool, was investigated as well as the influence of the moisture content on thermal transmittance. The investigation was carried out as a full-scale test under normal climate conditions in a moisture test house facility. Facade elements were built as timber frame constructions. Heat flow through the facade elements was measured with built-in heat flowmeters and the moisture content in the thermal insulation behind the wind barrier was measured with moisture measuring dowels. The test showed that the thermal performance of the tested type of cellulose loose-fill insulation material was significantly lower than the thermal performance of stone wool batts. The maximum moisture content of the insulation material was below, what in Denmark is considered critical for the onset of rot and growth of wood decaying fungi. The thermal transmittance did not change with changes in the moisture content within the investigated hygroscopic range. (author)

  15. Wrapped-IMLI: Thermal Insulation for Cryogenic Feed Lines Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA Exploration vehicles require improved technologies for passive thermal insulation for zero boil-off of cryopropellants during extended LEO and lunar surface...

  16. Estimating Clothing Thermal Insulation Using an Infrared Camera

    National Research Council Canada - National Science Library

    Lee, Jeong-Hoon; Kim, Young-Keun; Kim, Kyung-Soo; Kim, Soohyun

    2016-01-01

    In this paper, a novel algorithm for estimating clothing insulation is proposed to assess thermal comfort, based on the non-contact and real-time measurements of the face and clothing temperatures by an infrared camera...

  17. Outgassing of solid material into vacuum thermal insulation spaces

    Science.gov (United States)

    Wang, Pao-Lien

    1994-01-01

    Many cryogenic storage tanks use vacuum between inner and outer tank for thermal insulation. These cryogenic tanks also use a radiation shield barrier in the vacuum space to prevent radiation heat transfer. This shield is usually constructed by using multiple wraps of aluminized mylar and glass paper as inserts. For obtaining maximum thermal performance, a good vacuum level must be maintained with the insulation system. It has been found that over a period of time solid insulation materials will vaporize into the vacuum space and the vacuum will degrade. In order to determine the degradation of vacuum, the rate of outgassing of the insulation materials must be determined. Outgassing rate of several insulation materials obtained from literature search were listed in tabular form.

  18. Parametric Investigation of Optimum Thermal Insulation Thickness for External Walls

    Directory of Open Access Journals (Sweden)

    Omer Kaynakli

    2011-06-01

    Full Text Available Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs, the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focused on the investigation of these parameters that affect the optimum thermal insulation thickness for building walls. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building, the inflation rate, energy costs and thermal conductivity of insulation. However, the thickness decreased with increasing the discount rate, the insulation material cost, the total wall resistance, the coefficient of performance (COP of the cooling system and the solar radiation incident on a wall. In addition, the effects of these parameters on the total life-cycle cost, payback periods and energy savings were also investigated.

  19. Thermal conductivity of disperse insulation materials and their mixtures

    Science.gov (United States)

    Geža, V.; Jakovičs, A.; Gendelis, S.; Usiļonoks, I.; Timofejevs, J.

    2017-10-01

    Development of new, more efficient thermal insulation materials is a key to reduction of heat losses and contribution to greenhouse gas emissions. Two innovative materials developed at Thermeko LLC are Izoprok and Izopearl. This research is devoted to experimental study of thermal insulation properties of both materials as well as their mixture. Results show that mixture of 40% Izoprok and 60% of Izopearl has lower thermal conductivity than pure materials. In this work, material thermal conductivity dependence temperature is also measured. Novel modelling approach is used to model spatial distribution of disperse insulation material. Computational fluid dynamics approach is also used to estimate role of different heat transfer phenomena in such porous mixture. Modelling results show that thermal convection plays small role in heat transfer despite large fraction of air within material pores.

  20. Effective Thermal Conductivity of Insulating Material made from Recycled Newspapers

    Science.gov (United States)

    Yamada, Etsuro; Takahashi, Kaneko; Sato, Mitsuo; Ishii, Yukihiro

    In this paper, the experimental results are represented on the effective thermal conductivity of cellulose insulation powder which is made from recycled newspapers. This insulating material is useful for energy and resources saving. The steady state cylindrical absolute method is employed by considering the accuracy of measurement. The experimental results are compared with the ones measured previously by other methods. The main results obtained are as follows (1) The effective thermal conductivity of this insulating material increases with increasing temperature and effective specific density, respectively. But, these increasing rate is not so large. (2) The effective thermal conductivity is about 0.04-0.06[W/mK] at the range of the effective specific density less than 100 [kg/m3]. This value is comparable with other industrial insulating materials.

  1. Improved Thermal-Insulation Systems for Low Temperatures

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stanislaw D.

    2003-01-01

    Improved thermal-insulation materials and structures and the techniques for manufacturing them are undergoing development for use in low-temperature applications. Examples of low-temperature equipment for which these thermal insulation systems could provide improved energy efficiency include storage tanks for cryogens, superconducting electric-power-transmission equipment, containers for transport of food and other perishable commodities, and cold boxes for low-temperature industrial processes. These systems could also be used to insulate piping used to transfer cryogens and other fluids, such as liquefied natural gas, refrigerants, chilled water, crude oil, or low-pressure steam. The present thermal-insulation systems are layer composites based partly on the older class of thermal-insulation systems denoted generally as multilayer insulation (MLI). A typical MLI structure includes an evacuated jacket, within which many layers of radiation shields are stacked or wrapped close together. Low-thermal-conductivity spacers are typically placed between the reflection layers to keep them from touching. MLI can work very well when a high vacuum level (less than 10(exp-4) torr) is maintained and utmost care is taken during installation, but its thermal performance deteriorates sharply as the pressure in the evacuated space rises into the soft vacuum range [pressures greater than 0.1 torr (greater than 13 Pa)]. In addition, the thermal performance of MLI is extremely sensitive to mechanical compression and edge effects and can easily decrease from one to two orders of magnitude from its ideal value even when the MLI is kept under high vacuum condition. The present thermal-insulation systems are designed to perform well under soft vacuum level, in particular the range of 1 to 10 torr. They are also designed with larger interlayer spacings to reduce vulnerability to compression (and consequent heat leak) caused by installation and use. The superiority of these systems is the

  2. Comparative study of thermal insulation boards from leaf and bark ...

    African Journals Online (AJOL)

    The aim of this study was to compare the performance of insulation boards made from leave and bark fibres of Pilios tigma thonningii L.in terms of density, water absorption, apparent thermal conductivity, specific heat and thermal diffusivity. The leave and the bark fibres were prepared in form of squared boards of 200 mm x ...

  3. Thin Thermal-Insulation Blankets for Very High Temperatures

    Science.gov (United States)

    Choi, Michael K.

    2003-01-01

    Thermal-insulation blankets of a proposed type would be exceptionally thin and would endure temperatures up to 2,100 C. These blankets were originally intended to protect components of the NASA Solar Probe spacecraft against radiant heating at its planned closest approach to the Sun (a distance of 4 solar radii). These blankets could also be used on Earth to provide thermal protection in special applications (especially in vacuum chambers) for which conventional thermal-insulation blankets would be too thick or would not perform adequately.

  4. 24 CFR 3280.207 - Requirements for foam plastic thermal insulating materials.

    Science.gov (United States)

    2010-04-01

    ... mineral fiber insulation or an equivalent thermal barrier; or (3) The foam plastic insulating material has... thermal insulating materials. 3280.207 Section 3280.207 Housing and Urban Development Regulations Relating... SAFETY STANDARDS Fire Safety § 3280.207 Requirements for foam plastic thermal insulating materials. (a...

  5. Possibility of Using Metakaolin as Thermal Insulation Material

    Science.gov (United States)

    Rashad, Alaa M.

    2017-08-01

    The use of energy in the building sector accounts a significant part of the world's total energy and greenhouse gas emissions. In order to meet the demands of improved energy efficiency, thermal insulation of buildings plays an important role. To attain the highest possible thermal insulation, new insulation plaster types with low thermal conductivity values have been investigated and developed. In the current investigation, the possibility of using new plaster types based on metakaolin (MK) as heat insulation material and elevated temperature resistance has been studied and compared with that of traditional Portland cement plaster. Either cement or gypsum was used as a binder material. Three different plaster types containing MK were investigated as well as the traditional cement plaster (TC), which was used as a reference. Density and thermal conductivity values were measured. The compressive strength values before and after exposure to 600°C for 2 h were identified. The results showed that it is possible to produce different plaster types based on MK as heat insulation materials as well as elevated temperature resistance. MK plaster types exhibited approximately 65.7 % to 72 % lower thermal conductivity than that of TC plaster.

  6. Preparation of Thermal Insulation Plaster with FGD Gypsum

    Directory of Open Access Journals (Sweden)

    Yi-Chao Zhang

    2016-05-01

    Full Text Available Thermal insulation gypsum plaster was prepared from flue gas desulphurization (FGD gypsum. K12 is more recommendable as foaming agent, when the mass fraction of K12 is around 0.1 %, the setting time and compressive strength meet the requirements of gypsum-based construction materials. In the meanwhile, the thermal conductivity is 0.18 W m–1 K–1, which can be used as a thermal insulation material. The hemihydrate mixtures obtained, allow the design of a new wall structure, which is more efficient as a thermal insulation system. The wall heat transfer coefficient test was carried out to compare thermal performance of two different thermal insulation systems. Compared with the thermal performance of a conventional system, the heat transfer coefficient of the new system was reduced by 5.6 %. Finally, energy-saving analysis of a building was carried out to compare the energy-saving effect of the conventional and new systems of building. The energy-savings of the building with the new system increased by almost 2 %, thus resulting in low energy consumption of the building.

  7. Thermal insulation of wet shielded metal arc welds

    Science.gov (United States)

    Keenan, Patrick J.

    1993-06-01

    Computational and experimental studies were performed to determine the effect of static thermal insulation on the quality of wet shielded metal arc welds (SMAW). A commercially available heat flow and fluid dynamics spectral-element computer program was used to model a wet SMAW and to determine the potential effect on the weld cooling rate of placing thermal insulation adjacent to the weld line. Experimental manual welds were made on a low carbon equivalent (0.285) mild steel and on a higher carbon equivalent (0.410) high tensile strength steel, using woven fabrics of alumina-boria-silica fibers to insulate the surface of the plate being welded. The effect of the insulation on weld quality was evaluated through the use of post-weld Rockwell Scale hardness measurements on the surface of the weld heat affected zones (HAZ's) and by visual inspection of sectioned welds at 10 X magnification. The computational simulation demonstrated a 150% increase in surface HAZ peak temperature and a significant decrease in weld cooling rate with respect to uninsulated welds, for welds in which ideal insulation had been placed on the base plate surface adjacent to the weld line. Experimental mild steel welds showed a reduction in surface HAZ hardness attributable to insulation at a 77% significance level. A visual comparison of the cross-sections of two welds made in 0.410 carbon equivalent steel-with approximately equivalent heat input-revealed underbead cracking in the uninsulated weld but not in the insulated weld.

  8. Thermal Performance Testing of Order Dependancy of Aerogels Multilayered Insulation

    Science.gov (United States)

    Johnson, Wesley L.; Fesmire, James E.; Demko, J. A.

    2009-01-01

    Robust multilayer insulation systems have long been a goal of many research projects. Such insulation systems must provide some degree of structural support and also mechanical integrity during loss of vacuum scenarios while continuing to provide insulative value to the vessel. Aerogel composite blankets can be the best insulation materials in ambient pressure environments; in high vacuum, the thermal performance of aerogel improves by about one order of magnitude. Standard multilayer insulation (MU) is typically 50% worse at ambient pressure and at soft vacuum, but as much as two or three orders of magnitude better at high vacuum. Different combinations of aerogel and multilayer insulation systems have been tested at Cryogenics Test Laboratory of NASA Kennedy Space Center. Analysis performed at Oak Ridge National Laboratory showed an importance to the relative location of the MU and aerogel blankets. Apparent thermal conductivity testing under cryogenic-vacuum conditions was performed to verify the analytical conclusion. Tests results are shown to be in agreement with the analysis which indicated that the best performance is obtained with aerogel layers located in the middle of the blanket insulation system.

  9. Lightweight High-Temperature Thermal Insulation

    Science.gov (United States)

    Wagner, W. R.; Fasheh, J. I.

    1985-01-01

    Fine Ni/Cr fibers sintered into corrosion-resistant, fireproof batt. Possible applications include stoves, furnaces, safes, fire clothing, draperies in public buildings, wall firebreaks, airplane walls, and jetengine components. New insulation takes advantage of some of same properties of nickel/chromium alloy useful in heating elements in toasters, namely, corrosion and oxidation resistance even at high temperatures.

  10. Heat conductivity of high-temperature thermal insulators

    Science.gov (United States)

    Kharlamov, A. G.

    The book deals essentially with the mechanisms of heat transfer by conduction, convection, and thermal radiation in absorbing and transmitting media. Particular attention is given to materials for gas-cooled reactor systems, the temperature dependent conductivities of high-temperature insulations in vacuum, and the thermal conductivities of MgO, Al2O3, ZrO2, and other powders at temperatures up to 2000 C. The thermal conductivity of pyrolitic graphite and graphite foam are studied.

  11. Energy Consumption of Insulated Material Using Thermal Effect Analysis

    Directory of Open Access Journals (Sweden)

    Fadzil M. A.

    2017-01-01

    Full Text Available Wall is one of the structures elements that resist direct heat from the atmosphere. Modification on several structures is relevance to reduce filtrate thermal movement on wall. Insulation material seems to be suitable to be implemented since its purpose meets the heat resistance requirement. Insulation material applied as to generate positive impact in energy saving through reduction in total building energy consumption. Fiberglass is one of the insulation materials that can be used to insulate a space from heat and sound. Fiberglass is flammable insulation material with R Value rated of R-2.9 to R-3.8 which meets the requirement in minimizing heat transfer. Finite element software, ABAQUS v6.13 employed for analyze non insulated wall and other insulated wall with different wall thicknesses. The several calculations related to overall heat movement, total energy consumption per unit area of wall, life cycle cost analysis and determination of optimal insulation thickness is calculated due to show the potential of the implementation in minimize heat transfer and generate potential energy saving in building operation. It is hoped that the study can contribute to better understanding on the potential building wall retrofitting works in increasing building serviceability and creating potential benefits for building owner.

  12. Interior thermal insulation systems for historical building envelopes

    Science.gov (United States)

    Jerman, Miloš; Solař, Miloš; Černý, Robert

    2017-11-01

    The design specifics of interior thermal insulation systems applied for historical building envelopes are described. The vapor-tight systems and systems based on capillary thermal insulation materials are taken into account as two basic options differing in building-physical considerations. The possibilities of hygrothermal analysis of renovated historical envelopes including laboratory methods, computer simulation techniques, and in-situ tests are discussed. It is concluded that the application of computational models for hygrothermal assessment of interior thermal insulation systems should always be performed with a particular care. On one hand, they present a very effective tool for both service life assessment and possible planning of subsequent reconstructions. On the other, the hygrothermal analysis of any historical building can involve quite a few potential uncertainties which may affect negatively the accuracy of obtained results.

  13. Characterization of the thermal insulating properties of vacuum glazing

    Energy Technology Data Exchange (ETDEWEB)

    Ng, N. [School of Physics, University of Sydney, New South Wales 2006 (Australia)]. E-mail: n.ng@Physics.usyd.edu.au; Collins, R.E. [School of Physics, University of Sydney, New South Wales 2006 (Australia); So, L. [School of Physics, University of Sydney, New South Wales 2006 (Australia)

    2007-03-25

    Methods are described for characterizing the thermal insulating properties of vacuum glazing-two flat sheets of glass, hermetically sealed together around the edges containing a highly evacuated space, and separated by small pillars. The small-area guarded hot plate apparatus gives absolute measurements of the different heat flows through the glazing due to radiation, gaseous conduction and thermal conduction through the pillars. In the transient technique, a step temperature increase is applied to one side of the glazing, and the resultant slow temperature rise of the other glass sheet is measured. This method can be used in ageing studies to characterize glazings at elevated temperatures. In the cool-down method, one glass sheet of a glazing that is initially at high temperature is insulated, the opposite glass sheet is rapidly cooled, and the rate of cooling of the thermally insulated sheet is then measured.

  14. Channel microstructure and thermal insulation mechanism of sepiolite mineral nanofibers.

    Science.gov (United States)

    Wang, Fei; Liang, Jinsheng; Tang, Qingguo; Chen, Cong; Chen, Yalei

    2014-05-01

    The longitudinal and cross sectional TEM images of sepiolite mineral nanofibers were prepared by cutting in the direction parallel and perpendicular to nanofibers, and the channel microstructure of sepiolite nanofibers was studied. The thermal insulation mechanism of sepiolite nanofibers was analyzed according to the diagrammatic sketch obtained from the above experimental method. The results showed that many discontinuously connected bending shape channels with about 23-26 nm in diameter existed in the center region of nanofibers, and many discontinuously connected irregular micropores and mesopores with the size of about 1-9 nm existed on the wall of nanofibers. The main reasons for the formation of channel microstructure in sepiolite nanofibers were their minerogenetic conditions and the interaction between acid and high-speed airflow in the process of nanofibers preparation, and bubbles in the hydrotherm played a significant role in the microstructure formation. The thermal insulation performance of sepiolite nanofibers could be attributed to obstructive and infrared radiative thermal insulation.

  15. Reusable surface insulation thermal protection systems test evaluation status

    Science.gov (United States)

    Strouhal, G.; Tillian, D. J.

    1973-01-01

    Changes in coating morphology of mullite, silica, and ceramic mullite fiber at two heating rates are described followed by a discussion of the changes in surface chemistry that occur during convective heating tests. Subsequently, the surface chemistry changes observed are compared to similar data obtained from radiantly heated coatings and the significance of the difference between the results is discussed. Finally, the changes in chemistry of the coatings in cross section before and after convectively heated cyclic testing are discussed and the significance of surface chemistry changes are described. Results indicate that the thermal conductivity of mullite surface insulation is higher than that of silica insulation, based on thermal response data. Acoustic excitation of cracked silica tiles does not lead to catastrophic failure such as spallation or tile loss. Cracks in mullite material after thermal exposure lead to fracturing of the coating and surface insulation material after acoustic excitation.

  16. Prediction of the Effective Thermal Conductivity of Powder Insulation

    Science.gov (United States)

    Jin, Lingxue; Park, Jiho; Lee, Cheonkyu; Jeong, Sangkwon

    The powder insulation method is widely used in structural and cryogenic systems such as transportation and storage tanks of cryogenic fluids. The powder insulation layer is constructed by small particle powder with light weight and some residual gas with high porosity. So far, many experiments have been carried out to test the thermal performance of various kinds of powder, including expanded perlite, glass microspheres, expanded polystyrene (EPS). However, it is still difficult to predict the thermal performance of powder insulation by calculation due to the complicated geometries, including various particle shapes, wide powder diameter distribution, and various pore sizes. In this paper, the effective thermal conductivity of powder insulation has been predicted based on an effective thermal conductivity calculationmodel of porous packed beds. The calculation methodology was applied to the insulation system with expanded perlite, glass microspheres and EPS beads at cryogenic temperature and various vacuum pressures. The calculation results were compared with previous experimental data. Moreover, additional tests were carried out at cryogenic temperature in this research. The fitting equations of the deformation factor of the area-contact model are presented for various powders. The calculation results show agood agreement with the experimental results.

  17. Theoretical analysis of three methods for calculating thermal insulation of clothing from thermal manikin.

    Science.gov (United States)

    Huang, Jianhua

    2012-07-01

    There are three methods for calculating thermal insulation of clothing measured with a thermal manikin, i.e. the global method, the serial method, and the parallel method. Under the condition of homogeneous clothing insulation, these three methods yield the same insulation values. If the local heat flux is uniform over the manikin body, the global and serial methods provide the same insulation value. In most cases, the serial method gives a higher insulation value than the global method. There is a possibility that the insulation value from the serial method is lower than the value from the global method. The serial method always gives higher insulation value than the parallel method. The insulation value from the parallel method is higher or lower than the value from the global method, depending on the relationship between the heat loss distribution and the surface temperatures. Under the circumstance of uniform surface temperature distribution over the manikin body, the global and parallel methods give the same insulation value. If the constant surface temperature mode is used in the manikin test, the parallel method can be used to calculate the thermal insulation of clothing. If the constant heat flux mode is used in the manikin test, the serial method can be used to calculate the thermal insulation of clothing. The global method should be used for calculating thermal insulation of clothing for all manikin control modes, especially for thermal comfort regulation mode. The global method should be chosen by clothing manufacturers for labelling their products. The serial and parallel methods provide more information with respect to the different parts of clothing.

  18. A REVIEW OF COMPARATIVE EVALUATION OF THERMAL INSULATION MATERIALS FOR BUILDING WALL APPLICATIONS

    OpenAIRE

    Dr. RK. Jain *, Chouhan Balaji, Dhananjay Singh

    2016-01-01

    Attention towards the thermal performance of building materials, particularly thermal insulation systems for buildings, has grown in recent years. Thermal insulation of building walls has a significant effect on the reduction of thermal energy consumption in buildings Making a thermal insulation of a building external wall can in terms of economic aspects be approached as an investment. In this investment the cost is related to the purchase, transport and laying the insulation, whereas the pr...

  19. Estimating Clothing Thermal Insulation Using an Infrared Camera

    Directory of Open Access Journals (Sweden)

    Jeong-Hoon Lee

    2016-03-01

    Full Text Available In this paper, a novel algorithm for estimating clothing insulation is proposed to assess thermal comfort, based on the non-contact and real-time measurements of the face and clothing temperatures by an infrared camera. The proposed method can accurately measure the clothing insulation of various garments under different clothing fit and sitting postures. The proposed estimation method is investigated to be effective to measure its clothing insulation significantly in different seasonal clothing conditions using a paired t-test in 99% confidence interval. Temperatures simulated with the proposed estimated insulation value show closer to the values of actual temperature than those with individual clothing insulation values. Upper clothing’s temperature is more accurate within 3% error and lower clothing’s temperature is more accurate by 3.7%~6.2% error in indoor working scenarios. The proposed algorithm can reflect the effect of air layer which makes insulation different in the calculation to estimate clothing insulation using the temperature of the face and clothing. In future, the proposed method is expected to be applied to evaluate the customized passenger comfort effectively.

  20. Estimating Clothing Thermal Insulation Using an Infrared Camera

    Science.gov (United States)

    Lee, Jeong-Hoon; Kim, Young-Keun; Kim, Kyung-Soo; Kim, Soohyun

    2016-01-01

    In this paper, a novel algorithm for estimating clothing insulation is proposed to assess thermal comfort, based on the non-contact and real-time measurements of the face and clothing temperatures by an infrared camera. The proposed method can accurately measure the clothing insulation of various garments under different clothing fit and sitting postures. The proposed estimation method is investigated to be effective to measure its clothing insulation significantly in different seasonal clothing conditions using a paired t-test in 99% confidence interval. Temperatures simulated with the proposed estimated insulation value show closer to the values of actual temperature than those with individual clothing insulation values. Upper clothing’s temperature is more accurate within 3% error and lower clothing’s temperature is more accurate by 3.7%~6.2% error in indoor working scenarios. The proposed algorithm can reflect the effect of air layer which makes insulation different in the calculation to estimate clothing insulation using the temperature of the face and clothing. In future, the proposed method is expected to be applied to evaluate the customized passenger comfort effectively. PMID:27005625

  1. Estimating Clothing Thermal Insulation Using an Infrared Camera.

    Science.gov (United States)

    Lee, Jeong-Hoon; Kim, Young-Keun; Kim, Kyung-Soo; Kim, Soohyun

    2016-03-09

    In this paper, a novel algorithm for estimating clothing insulation is proposed to assess thermal comfort, based on the non-contact and real-time measurements of the face and clothing temperatures by an infrared camera. The proposed method can accurately measure the clothing insulation of various garments under different clothing fit and sitting postures. The proposed estimation method is investigated to be effective to measure its clothing insulation significantly in different seasonal clothing conditions using a paired t-test in 99% confidence interval. Temperatures simulated with the proposed estimated insulation value show closer to the values of actual temperature than those with individual clothing insulation values. Upper clothing's temperature is more accurate within 3% error and lower clothing's temperature is more accurate by 3.7%~6.2% error in indoor working scenarios. The proposed algorithm can reflect the effect of air layer which makes insulation different in the calculation to estimate clothing insulation using the temperature of the face and clothing. In future, the proposed method is expected to be applied to evaluate the customized passenger comfort effectively.

  2. Waterproof Silicone Coatings of Thermal Insulation and Vaporization Method

    Science.gov (United States)

    Cagliostro, Domenick E. (Inventor)

    1999-01-01

    Thermal insulation composed of porous ceramic material can be waterproofed by producing a thin silicone film on the surface of the insulation by exposing it to volatile silicone precursors at ambient conditions. When the silicone precursor reactants are multi-functional siloxanes or silanes containing alkenes or alkynes carbon groups higher molecular weight films can be produced. Catalyst are usually required for the silicone precursors to react at room temperature to form the films. The catalyst are particularly useful in the single component system e.g. dimethylethoxysilane (DNMS) to accelerate the reaction and decrease the time to waterproof and protect the insulation. In comparison to other methods, the chemical vapor technique assures better control over the quantity and location of the film being deposited on the ceramic insulation to improve the waterproof coating.

  3. Status of reusable surface insulation thermal protection system technology programs

    Science.gov (United States)

    Greenshields, D. H.; Meyer, A. J.; Tillian, D. J.

    1972-01-01

    The development of three low-density rigidized insulation materials for the shuttle TPS application is reported. These materials consist of one high purity silica system and two systems based on mullite, an aluminum silicate. Both systems consist of fibers joined together with appropriate binders to obtain a rigidized insulation composite. Both material systems require the application of a glassy coating to provide a wear resistant, high emittance surface and to prevent the absorption of water by the fiber matrix. The technology program has addressed the development of water impervious coatings, methods of assembling the materials in design concepts while minimizing the thermal stress in the insulation, achieving compatibility between the RSI material and the structural system, and test evaluations to demonstrate the feasibility of the surface insulation concept.

  4. Preparation of a Novel Water-based Acrylic Multi-Thermal Insulation Coating

    Directory of Open Access Journals (Sweden)

    Xiufang YE

    2017-08-01

    Full Text Available To efficiently improve the thermal insulation effect of coatings, a novel water-based acrylic multi-thermal insulation coating (multi-WATIC combined with thermal obstruction, echo, and radiation was prepared. The category and ratio of thermal insulation functional fillers are crucial. First, water-based acrylic thermal insulation coating (WATIC with single thermal insulation functional fillers was prepared, and the thermal insulation property tests were done. Thereafter, a novel multi-WATIC was prepared combined with the 3 thermal insulation functional fillers together, and the formula of the novel multi-WATIC was optimized based on single factor experiments by response surface methodology (RSM. Test results showed that multi-WATIC has excellent thermal insulation property, and the fitting result obtained by RSM is in good agreement with test data.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.16090

  5. Environmental impact of thermal insulations: How do natural insulation products differ from synthetic ones?

    Science.gov (United States)

    Dovjak, M.; Košir, M.; Pajek, L.; Iglič, N.; Božiček, D.; Kunič, R.

    2017-10-01

    As the environmental awareness of the public is rising and at the same time contemporary buildings are becoming more and more energy efficient, the focus is shifting towards the usage of environmentally friendly building products. Human decisions are often driven by emotions and perceptions. Consequently, there exists a strong tendency towards preferring “natural” constructional products to the synthetic ones, especially in the case of thermal insulations. Life cycle assessment (LCA) has enabled an opportunity to widen the meaning of the word “environmentally friendly”, giving researchers and building designers an objective decision making tool to determine the environmental impact of building products, building components and buildings as a whole. The purpose of this study was to compare the environmental impact of various thermal insulations for the cradle to gate life cycle stages, based on a unified functional unit. Overall, 15 most commonly used thermal insulation products were analysed and classified into natural and synthetic groups. Based on the differentiation, we compared the impact in the selected environmental categories and identified the most influential environmental drivers. The results show that in some environmental categoriesnatural thermal insulations perform better (i.e. global warming potential), whilein others (i.e. eutrophication potential) they underperform. However, environmental impact trends can be identified, specifically for the natural and the synthetic materials.

  6. Multilayer insulation thermal protection systems technology

    Science.gov (United States)

    Hyde, E. H.

    1971-01-01

    A summary is presented of the work performed by Marshall Space Flight Center (MSFC) and industry toward the development of flight-type multilayer insulation(MLI) systems. The MSFC MLI program is divided into three large categories: (1) the generation and compilation of MLI composite test data; (2) the analysis, design, and testing of heat flow through MLI applied to ducting, seams, electrical feedthroughs, structural supports, and the tank sidewall; and (3) the development, modification, and utilization of new testing procedures, tanks, and the test facilities. Numerous data have been generated, analyzed, and documented on different MLI composites.

  7. Quantitative analysis of silica aerogel-based thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2015-01-01

    A mathematical heat transfer model for a silica aerogel-based thermal insulation coating was developed. The model can estimate the thermal conductivity of a two-component (binder-aerogel) coating with potential binder intrusion into the nano-porous aerogel structure. The latter is modelled using......, to get an indication of the effect of important model parameters on the thermal conductivity of an insulation coating. With relevant data available for service life exposure conditions and raw material costs, the model can also be used as an optimization algorithm....... and experimental data with shell thickness and/or thermal conductivity of the shell as adjustable parameters. However, the experimental data was not sufficiently detailed to allow a separation of the effects of the two parameters. In the ideal case of no aerogel binder intrusion, a comparison with a coating...

  8. Parametric fuselage design : Integration of mechanics and acoustic & thermal insulation

    NARCIS (Netherlands)

    Krakers, L.A.

    2009-01-01

    Designing a fuselage is a very complex process, which involves many different aspects like strength and stability, fatigue, damage tolerance, fire resistance, thermal and acoustic insulation but also inspection, maintenance, production and repair aspects. It is difficult to include all design

  9. Closed-pore Insulation Thermal Protection System Design Concept Development

    Science.gov (United States)

    Varisco, A.; Harris, H. G.

    1973-01-01

    The development of a unique closed-pore ceramic foam insulation (CPI) produced from low cost fly ash cenospheres is reported for space shuttle external thermal protection. Two basic design approaches were developed: bonded and mechanically fastened. A description of the concepts is presented in addition to fabrication and test results.

  10. Electrically and Thermally Insulated Joint for Liquid Nitrogen Transfer

    DEFF Research Database (Denmark)

    Rasmussen, Carsten; Jensen, Kim Høj; Holbøll, Joachim T.

    1999-01-01

    A prototype of a superconducting cable is currently under construction. The cable conductor is cooled by liquid nitrogen in order to obtain superconductivity. The peripheral cooling circuit is kept at ground potential. This requires a joint which insulates both electrically and thermally...

  11. Wood moisture monitoring during log house thermal insulation mounting

    Directory of Open Access Journals (Sweden)

    Pavla Kotásková

    2011-01-01

    Full Text Available The current designs of thermal insulation for buildings concentrate on the achievement of the required heat transmission coefficient. However, another factor that cannot be neglected is the assessment of the possible water vapour condensation inside the construction. The aim of the study was to find out whether the designed modification of the cladding structure of an existing log house will or will not lead to a risk of possible water vapour condensation in the walls after an additional thermal insulation mounting. The condensation could result in the increase in moisture of the walls and consequently the constructional timber, which would lead to the reduction of the timber construction strength, wood degradation by biotic factors – wood-destroying insects, mildew or wood-destroying fungi. The main task was to compare the theoretically established values of moisture of the constructional timber with the values measured inside the construction using a specific example of a thermal insulated log house. Three versions of thermal insulation were explored to find the solution of a log house reconstruction which would be the optimum for living purposes. Two versions deal with the cladding structure with the insulation from the interior, the third version deals with an external insulation.In a calculation model the results can be affected to a great degree by input values (boundary conditions. This especially concerns the factor of vapour barrier diffusion resistance, which is entered in accordance with the producer’s specifications; however, its real value can be lower as it depends on the perfectness and correctness of the technological procedure. That is why the study also includes thermal technical calculations of all designed insulation versions in the most unfavourable situation, which includes the degradation of the vapour barrier down to 10% efficiency, i.e. the reduction of the diffusion resistance factor to 10% of the original value

  12. Comparative study of hygrothermal properties of five thermal insulation materials

    Directory of Open Access Journals (Sweden)

    Laure Ducoulombier

    2017-09-01

    Full Text Available The objective of this article is to carry out a comparative study of the main hygrothermal properties of five thermal insulation materials for buildings. These properties are necessary for a correct prediction of heat and moisture transfers through the walls and the selection of the most appropriate materials according to the specific buildings. The studied materials were glass wool, rock wool, expanded polystyrene, wood fiberboard and polyester fiberfill. The article is divided into three parts. The first part presents the phenomena of hygrothermal transfers in walls in order to understand the need for determining specific properties of the insulating materials. The second part describes in details the five studied insulating materials and the methods used for the characterization and identification of their main properties. Finally, the last part presents the experimental results and makes comparisons between materials. The differences between the insulating materials are brought out, such as the strong dependence of the thermal conductivity of polystyrene on temperature, or the good permeability of fibrous insulating materials to water vapor. A detailed analysis of the obtained results is presented.

  13. The advantage of selection of mineral thermal insulation materials with the structural properties for thermal insulation in buildings

    Directory of Open Access Journals (Sweden)

    Janžekovič Ines M.

    2014-01-01

    Full Text Available The paper deals with the problem of energy efficiency in Serbia. It gives a general overview of the energy losses and focuses on energy losses in buildings, which is recognized as one of the most problematic sectors as the energy losses concerns. By the very fact there is a need for more efficient implementation of measures to reduce energy losses through education and increased awareness of citizens about the proper ways of performing thermal protection of buildings. The paper points out the problems that arise when selecting the inadequate solutions of performing thermal insulation of buildings and suggests some solutions for the proper selection of materials for thermal insulation and in setting the appropriate requirements for thermal envelope for buildings.

  14. Thermal Performance of Insulating Cryogenic Pin Spacers

    CERN Document Server

    Darve, C

    1998-01-01

    Following the proposal to introduce an actively cooled radiation screen (5-10 K) for the LHC machine, the design of the LHC cryostat foresees the need for spacers between the cold mass and the radiati on screen. The thermal impedance of the chosen material should be very high and the shape selected to withstrand the contact stress due to the displacements induced by the coll-down and warm-up transi ent. A cryogenic experiment dedicated to studying the thermal behaviour of several proposed spacers was performed at the cryogenics laboratory of CERN before choosing the one to be used for further i nvestigation on the LHC full-scale Cryostat Thermal Model [1] [2]. This paper describes a quantitative analysis leading to the choice of the spacer.

  15. Investigation of thermo-physical properties of thermal insulation coating

    Science.gov (United States)

    Kopčok, Michal; Lukovičová, Jozefa; Kačur, Jozef; Pavlendová, Gabriela

    2017-07-01

    This paper examines the thermal properties of thermal insulation coating applied to the building materials surfaces. The main objective is to determine the insulation coating impact on the heat flux transfer. The heat flux is modelled in terms of the heat transfer coefficient on the surface of a solid body. The thermal conductivity and heat transfer coefficient are obtained from the solution of the inverse heat conduction problem in 3D, based on the temperature measurements. The real temperature evolution is perturbed due to intrinsic properties of the measuring apparatus. We correct this situation via modelling a thermocouple function. Afterwards the determination procedure of the heat flux transfer parameters is a standard solution of the inverse problem based on the minimization of discrepancy between corrected measured data and computed temperature data.

  16. Aspects of corrosion testing of thermal-insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Sheppard, K.G.; Weil, R.

    1983-01-01

    The literature dealing with corrosion by thermal-insulating materials in residential buildings is reviewed. Current corrosiveness test methods are discussed. In view of their shortcomings, the need for a new procedure is evident. Possible methods applicable to various types of insulation are considered. The program for developing the new procedure is outlined. Preliminary test results indicate relationships between existing coupon and rapidly executable electrochemical tests. Field data, which are beginning to be collected, are needed to establish the validity of the new test and its ability to predict behavior under service conditions.

  17. Investigation on Thermal Properties of Composite of Rice Husk, Corncob and Baggasse for Building Thermal Insulation

    OpenAIRE

    Kyauta E.E. Dauda D.M; Justin E

    2014-01-01

    The thermal properties of some Agricultural waste ( Rice Husk, Bagasse and Corncob) was investigated with the purpose of determining their use as insulators. Using varied composite percentages of each sample wastes at increasing and decreasing quantities to determine best mixtures has assisted in accurate recommendation. The work has explored the potentials for using composite samples of Rice Husk, Bagasse and Corncob as materials for thermal insulation, a solution which offers a reduction...

  18. Reusable Thermal Barrier for Insulation Gaps

    Science.gov (United States)

    Saladee, C. E.

    1985-01-01

    Filler composed of resilient, heat-resistant materials. Thermal barrier nestles snugly in gap between two tiles with minimal protrusion beyond faces of surrounding tiles. When removed from gap, barrier springs back to nearly original shape. Developed for filling spaces between tiles on Space Shuttle, also used in furnaces and kilns.

  19. Ternary binder based plasters with improved thermal insulating ability

    Science.gov (United States)

    Čáchová, M.; Koňáková, D.; Vejmelková, E.; Vyšvařil, M.

    2017-10-01

    New kind of plasters with improved thermal insulating ability are presented in this article. Improvement was reached by utilization of lightweight expanded perlite with high porosity. The second used aggregate was silica sand. Regarding the binder, three kind were combined for the reason of better plaster performance. Pure lime, Portland cement and pozzolanic ceramic powder were employed. Basic physical properties and thermal characteristics were determined. The porosity of plasters reached desired higher value about 50% and the thermal conductivity in dry state was lower than 0.16 Wm‑1K‑1.

  20. Thermal insulation and body temperature wearing a thermal swimsuit during water immersion.

    Science.gov (United States)

    Wakabayashi, Hitoshi; Hanai, Atsuko; Yokoyama, Shintaro; Nomura, Takeo

    2006-09-01

    This study evaluated the effects of a thermal swimsuit on body temperatures, thermoregulatory responses and thermal insulation during 60 min water immersion at rest. Ten healthy male subjects wearing either thermal swimsuits or normal swimsuits were immersed in water (26 degrees C or 29 degrees C). Esophageal temperature, skin temperatures and oxygen consumption were measured during the experiments. Metabolic heat production was calculated from oxygen consumption. Heat loss from skin to the water was calculated from the metabolic heat production and the change in mean body temperature during water immersion. Total insulation and tissue insulation were estimated by dividing the temperature difference between the esophagus and the water or the esophagus and the skin with heat loss from the skin. Esophageal temperature with a thermal swimsuit was higher than that with a normal swimsuit at the end of immersion in both water temperature conditions (pthermal swimsuit than with a normal swimsuit in both water temperatures (pinsulation with the thermal swimsuit was higher than that with a normal swimsuit due to insulation of the suit at both water temperatures (pinsulation was similar in all four conditions, but significantly higher with the thermal swimsuit in both water temperature conditions (pthermal swimsuit. A thermal swimsuit can increase total insulation and reduce heat loss from the skin. Therefore, subjects with thermal swimsuits can maintain higher body temperatures than with a normal swimsuit and reduce shivering thermo-genesis.

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

    Directory of Open Access Journals (Sweden)

    Jolanta VĖJELIENĖ

    2011-07-01

    Full Text Available 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

  2. Thermal conductivity of wool and wool-hemp insulation

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Z.; Wells, C.M.; Carrington, C.G. [University of Otago, Dunedin (New Zealand). Dept. of Physics; Hewitt, N.J. [University of Ulster, Jordanstown (United Kingdom). Centre for Sustainable Technologies

    2006-01-15

    Measurements have been obtained for the thermal resistance of sheep-wool insulation and wool-hemp mixtures, both in the form of bonded insulation batts, using a calibrated guarded hot-box. The density was 9.6-25.9 kg m{sup -3} for the wool and 9.9-18.1 kg m{sup -3} for the wool-hemp mixtures. The measurements were made at a mean sample temperature of 13.3{sup o}C using a calibrated guarded hot-box. The estimated uncertainly in the resistance measurements was of the order of {+-}7%. The thermal conductivity of the samples, derived from the thermal resistance measurements on the basis of the measured thickness, was well correlated with the density, although the variation with density was larger than that obtained in previous studies. The conductivity of the wool-hemp samples was not significantly different from that of the wool samples at the same density. Moisture uptake produced an increase of less than 5% in the conductivity of the bonded wool insulation for an increase in absorbed moisture content of 20%. The thermal resistance was 1.6% lower on average for samples oriented in the horizontal plane rather than the vertical plane, but this difference is not significant. (author)

  3. Study on Thermal Insulation Zeolite by Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Huiping Song

    2014-01-01

    Full Text Available This paper takes the coal fly ash as the material and makes zeolite with low thermal conductivity under a two-step synthesis for the purpose of thermal insulation. It studies main factors affecting zeolite such as the different concentration of NaOH, the solid-liquid ratio, the silica-alumina ratio, and the crystallization temperature. The optimal conditions were obtained that the NaOH concentration was 3 mol/L, the solid-liquid ratio was 10 : 1, the silica-alumina ratio was 2, and the crystallization temperature was 12°C. Zeolites have multiple pores and skeletal structures under SEM observation. The mean particle size was 2.78 um of concentrated distribution. The pore volume was 0.148 m3/g measured by BET analysis, the specific surface was 118.6 m2/g, and the thermal conductivity was 0.153 W/(m·K. Zeolite was proved to be a qualified insulation material which can be used in thermal insulation coating as a new material of energy conservation.

  4. Thin Thermal-Insulation Blankets for Very High Temperatures

    Science.gov (United States)

    Choi, Michael K.

    2003-01-01

    Thermal-insulation blankets of a proposed type would be exceptionally thin and would endure temperatures up to 2,100 C. These blankets were originally intended to protect components of the NASA Solar Probe spacecraft against radiant heating at its planned closest approach to the Sun (a distance of 4 solar radii). These blankets could also be used on Earth to provide thermal protection in special applications (especially in vacuum chambers) for which conventional thermal-insulation blankets would be too thick or would not perform adequately. A blanket according to the proposal (see figure) would be made of molybdenum, titanium nitride, and carbon- carbon composite mesh, which melt at temperatures of 2,610, 2,930, and 2,130 C, respectively. The emittance of molybdenum is 0.24, while that of titanium nitride is 0.03. Carbon-carbon composite mesh is a thermal insulator. Typically, the blanket would include 0.25-mil (.0.00635-mm)-thick hot-side and cold-side cover layers of molybdenum. Titanium nitride would be vapor-deposited on both surfaces of each cover layer. Between the cover layers there would be 10 inner layers of 0.15-mil (.0.0038-mm)-thick molybdenum with vapor-deposited titanium nitride on both sides of each layer. The thickness of each titanium nitride coat would be about 1,000 A. The cover and inner layers would be interspersed with 0.25-mil (0.00635-mm)-thick layers of carbon-carbon composite mesh. The blanket would have total thickness of 4.75 mils (approximately equal to 0.121 mm) and an areal mass density of 0.7 kilograms per square meter. One could, of course, increase the thermal- insulation capability of the blanket by increasing number of inner layers (thereby unavoidably increasing the total thickness and mass density).

  5. Repeatability Measurements of Apparent Thermal Conductivity of Multilayer Insulation (MLI)

    Science.gov (United States)

    Vanderlaan, M.; Stubbs, D.; Ledeboer, K.; Ross, J.; Van Sciver, S.; Guo, W.

    2017-12-01

    This report presents and discusses the results of repeatability experiments gathered from the multi-layer insulation thermal conductivity experiment (MIKE) for the measurement of the apparent thermal conductivity of multi-layer insulation (MLI) at variable boundary temperatures. Our apparatus uses a calibrated thermal link between the lower temperature shield of a concentric cylinder insulation assembly and the cold head of a cryocooler to measure the heat leak. In addition, thermocouple readings are taken in-between the MLI layers. These measurements are part of a multi-phase NASA-Yetispace-FSU collaboration to better understand the repeatability of thermal conductivity measurements of MLI. NASA provided five 25 layer coupons and requested boundary temperatures of 20 K and 300 K. Yetispace provided ten 12-layer coupons and requested boundary temperatures of 77 K and 293 K. Test conditions must be met for a duration of four hours at a steady state variance of less than 0.1 K/hr on both cylinders. Temperatures from three Cernox® temperature sensors on each of the two cylinders are averaged to determine the boundary temperatures. A high vacuum, less than 10-5 torr, is maintained for the duration of testing. Layer density varied from 17.98 – 26.36 layers/cm for Yetispace coupons and 13.05 – 17.45 layers/cm for the NASA coupons. The average measured heat load for the Yetispace coupons was 2.40 W for phase-one and 2.92 W for phase-two. The average measured heat load for the NASA coupons was 1.10 W. This suggests there is still unknown variance of MLI performance. It has been concluded, variations in the insulation installation heavy effect the apparent thermal conductivity and are not solely dependent on layer density.

  6. Comparison Study of Thermal Insulation Characteristics from Oil Palm Fibre

    Directory of Open Access Journals (Sweden)

    Hassan S.

    2014-07-01

    Full Text Available In this study, investigation was conducted to study the use of solid biomass from palm oil mill as insulation material. The experimental study concentrates on using oil palm fiber to determine the unidirectional thermal conductivity, k. The experiment was conducted at different temperature ranges and packing density. The values of k obtained were found to be 0.2 W/m.K to 0.069 W/m.K for a packing density between 66 kg/m3 to 110 kg/m3, and at a temperature between 40ºC to 70ºC. Comparisons were made with others common insulating materials, and it was found that the experimental k values for oil palm waste insulation was lower by between 4 to 56 times for rockwool and between 7 to 57 times for glass fiber at low temperatures. The value k of oil palm fiber however showed an increase at higher temperatures and was lower at lower packing densities. Although not being able to match the k values of common insulators at higher temperatures, other factors such as cost and environmental benefits of using waste material should be taken into consideration and hence encouraging its use as at least a supplement to existing insulation materials

  7. Layered Thermal Insulation Systems for Industrial and Commercial Applications

    Science.gov (United States)

    Fesmire, James E.

    2015-01-01

    From the high performance arena of cryogenic equipment, several different layered thermal insulation systems have been developed for industrial and commercial applications. In addition to the proven areas in cold-work applications for piping and tanks, the new Layered Composite Insulation for Extreme Environments (LCX) has potential for broader industrial use as well as for commercial applications. The LCX technology provides a unique combination of thermal, mechanical, and weathering performance capability that is both cost-effective and enabling. Industry applications may include, for example, liquid nitrogen (LN2) systems for food processing, liquefied natural gas (LNG) systems for transportation or power, and chilled water cooling facilities. Example commercial applications may include commercial residential building construction, hot water piping, HVAC systems, refrigerated trucks, cold chain shipping containers, and a various consumer products. The LCX system is highly tailorable to the end-use application and can be pre-fabricated or field assembled as needed. Product forms of LCX include rigid sheets, semi-flexible sheets, cylindrical clam-shells, removable covers, or flexible strips for wrapping. With increasing system control and reliability requirements as well as demands for higher energy efficiencies, thermal insulation in harsh environments is a growing challenge. The LCX technology grew out of solving problems in the insulation of mechanically complex cryogenic systems that must operate in outdoor, humid conditions. Insulation for cold work includes equipment for everything from liquid helium to chilled water. And in the middle are systems for LNG, LN2, liquid oxygen (LO2), liquid hydrogen (LH2) that must operate in the ambient environment. Different LCX systems have been demonstrated for sub-ambient conditions but are capable of moderately high temperature applications as well.

  8. Lightweight Thermal Insulation for a Liquid-Oxygen Tank

    Science.gov (United States)

    Willen, G. Scott; Lock, Jennifer; Nieczkoski, Steve

    2005-01-01

    A proposed lightweight, reusable thermal-insulation blanket has been designed for application to a tank containing liquid oxygen, in place of a non-reusable spray-on insulating foam. The blanket would be of the multilayer-insulation (MLI) type and equipped with a pressure-regulated nitrogen purge system. The blanket would contain 16 layers in two 8-layer sub-blankets. Double-aluminized polyimide 0.3 mil (.0.008 mm) thick was selected as a reflective shield material because of its compatibility with oxygen and its ability to withstand ionizing radiation and high temperature. The inner and outer sub-blanket layers, 1 mil (approximately equals 0.025 mm) and 3 mils (approximately equals 0.076 mm) thick, respectively, would be made of the double-aluminized polyimide reinforced with aramid. The inner and outer layers would provide structural support for the more fragile layers between them and would bear the insulation-to-tank attachment loads. The layers would be spaced apart by lightweight, low-thermal-conductance netting made from polyethylene terephthalate.

  9. Dynamic Thermal Features of Insulated Blocks: Actual Behavior and Myths

    Directory of Open Access Journals (Sweden)

    Marta Cianfrini

    2017-11-01

    Full Text Available The latest updates in the European directive on energy performance of buildings have introduced the fundamental “nearly zero-energy building (NZEB” concept. Thus, a special focus needs to be addressed to the thermal performance of building envelopes, especially concerning the role played by thermal inertia in the energy requirements for cooling applications. In fact, a high thermal inertia of the outer walls results in a mitigation of the daily heat wave, which reduces the cooling peak load and the related energy demand. The common assumption that high mass means high thermal inertia typically leads to the use of high-mass blocks. Numerical and experimental studies on thermal inertia of hollow envelope components have not confirmed this general assumption, even though no systematic analysis is readily available in the open literature. Yet, the usually employed methods for the calculation of unsteady heat transfer through walls are based on the hypothesis that such walls are composed of homogeneous layers. In this framework, a study of the dynamic thermal performance of insulated blocks is brought forth in the present paper. A finite-volume method is used to solve the two-dimensional equation of conduction heat transfer, using a triangular-pulse temperature excitation to analyze the heat flux response. The effects of both the type of clay and the insulating filler are investigated and discussed at length. The results obtained show that the wall front mass is not the basic independent variable, since clay and insulating filler thermal diffusivities are more important controlling parameters.

  10. Thermal coupon testing of Load-Bearing Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Heckle, K. W.; Hurd, J.

    2014-01-01

    Advanced liquid hydrogen storage concepts being considered for long duration space travel incorporate refrigeration systems and cryocoolers to lower the heat load. Using a refrigeration loop to intercept the energy flowing through MLI to a liquid hydrogen tank at a temperature between the environment and the liquid hydrogen can lower the heat load on the propellant system by as much as 50%. However, the refrigeration loop requires structural integration into the MLI. Use of a more traditional concept of MLI underneath this refrigeration loop requires that a structural system be put in place to support the loop. Such structures, even when thermally optimized, present a relatively large parasitic heat load into the tank. Through NASA small business innovation research funding, Quest Thermal Group and Ball Aerospace have been developing a structural MLI based insulation system. These systems are designed with discrete polymeric spacers between reflective layers instead of either dacron or silk netting. The spacers (or posts) have an intrinsic structural capability that is beyond that of just supporting the internal insulation mechanical loads. This new MLI variant called Load Bearing MLI (LB-MLI) has been developed specifically for the application of supporting thermal shields within the insulation system. Test articles (coupons) of the new LB-MLI product were fabricated for thermal performance testing using liquid nitrogen at Kennedy Space Center (KSC) and using cryocooler based calorimetry at Florida State University. The test results and analysis are presented. Thermal models developed for correlation with the thermal testing results both at KSC and testing that was performed at Florida State University are also discussed.

  11. Study on Thermal Insulation Zeolite by Coal Fly Ash

    OpenAIRE

    Huiping Song; Nan Zheng; Fangbin Xue; Fangqin Cheng

    2014-01-01

    This paper takes the coal fly ash as the material and makes zeolite with low thermal conductivity under a two-step synthesis for the purpose of thermal insulation. It studies main factors affecting zeolite such as the different concentration of NaOH, the solid-liquid ratio, the silica-alumina ratio, and the crystallization temperature. The optimal conditions were obtained that the NaOH concentration was 3 mol/L, the solid-liquid ratio was 10 : 1, the silica-alumina ratio was 2, and the crysta...

  12. Structural design aspects of reusable surface insulation thermal protection systems.

    Science.gov (United States)

    Michalak, R. J.; Hess, T. E.; Gluck, R. L.

    1972-01-01

    Low density fiber ceramic materials coated with refractory ceramics meet the requirements of reusable low weight thermal protection systems. The structural characteristics of this class of material impose unique design and analysis requirements on the application to spacecraft structural elements. Finite element type stress analysis techniques are required to adequately predict the structural response of the system. Parametric analyses have been performed to determine the response of the system to variations in geometry, and to thermal and structural load conditions. Sensitivity of coating, insulation and attachment stresses are presented and critical failure modes are identified.

  13. Transient Thermal Testing and Analysis of a Thermally Insulating Structural Sandwich Panel

    Science.gov (United States)

    Blosser, Max L.; Daryabeigi, Kamran; Bird, Richard K.; Knutson, Jeffrey R.

    2015-01-01

    A core configuration was devised for a thermally insulating structural sandwich panel. Two titanium prototype panels were constructed to illustrate the proposed sandwich panel geometry. The core of one of the titanium panels was filled with Saffil(trademark) alumina fibrous insulation and the panel was tested in a series of transient thermal tests. Finite element analysis was used to predict the thermal response of the panel using one- and two-dimensional models. Excellent agreement was obtained between predicted and measured temperature histories.

  14. Thermal resistances of air in cavity walls and their effect upon the thermal insulation performance

    Energy Technology Data Exchange (ETDEWEB)

    Bekkouche, S.M.A.; Cherier, M.K.; Hamdani, M.; Benamrane, N. [Application of Renewable Energies in Arid and Semi Arid Environments /Applied Research Unit on Renewable Energies/ EPST Development Center of Renewable Energies, URAER and B.P. 88, ZI, Gart Taam Ghardaia (Algeria); Benouaz, T. [University of Tlemcen, BP. 119, Tlemcen R.p. 13000 (Algeria); Yaiche, M.R. [Development Center of Renewable Energies, CDER and B.P 62, 16340, Route de l' Observatoire, Bouzareah, Algiers (Algeria)

    2013-07-01

    The optimum thickness in cavity walls in buildings is determined under steady conditions; the heat transfer has been calculated according to ISO 15099:2003. Two forms of masonry units are investigated to conclude the advantage of high thermal emissivity. The paper presents also some results from a study of the thermal insulation performance of air cavities bounded by thin reflective material layer 'eta = 0.05'. The results show that the most economical cavity configuration depends on the thermal emissivity and the insulation material used.

  15. Characterization of systems for external insulation and retrofitting with emphasis on the thermal performance

    DEFF Research Database (Denmark)

    Rudbeck, Claus; Rose, Jørgen

    1999-01-01

    or unsatisfactory architectural look. One way of solving these problems is by adding a retrofitting system with thermal insulation to the existing building envelope. If external insulation systems are used, a new rain screen is applied on the outside of the insulation. Insulation can be applied either on the inside...... to include the effect of thermal bridges by performing simple calculations, a task which normally requires the use of numerical models. The results show that thermal bridges in external insulation systems may decrease their thermal resistance by more than 25%.Key parameters was calculated by the use...... or the outside of the existing building envelope, but internal insulation has many disadvantages compared to external insulation. Several external insulation systems exist, each with different properties making it difficult for building designers to choose between systems in an objective manner.To help...

  16. Effect of composition on thermal conductivity of silica insulation media.

    Science.gov (United States)

    Park, Sung; Kwon, Young-Pil; Kwon, Hyuk-Chon; Lee, Hae-Weon; Lee, Jae Chun

    2008-10-01

    Nano-sized fumed silica-based insulation media were prepared by adding TiO2 powders and ceramic fibers as opacifiers and structural integrity improvers, respectively. The high temperature thermal conductivities of the fumed silica-based insulation media were investigated using different types of TiO2 opacifier and by varying its content. The opacifying effects of nanostructured TiO2 powders produced by homogeneous precipitation process at low temperatures (HPPLT) were compared with those of commercial TiO2 powder. The nanostructured HPPLT TiO2 powder with a mean particle size of 1.8 microm was more effective to reduce radiative heat transfer than the commercial one with a similar mean particle size. The insulation samples with the HPPLT TiO2 powder showed about 46% lower thermal conductivity at temperatures of about 820 degrees C than those with the commercial one. This interesting result might be due to the more effective radiation scattering efficiency of the nanostructured HPPLT TiO2 powder which has better gap filling and coating capability in nano-sized composite compacts.

  17. Thermal Analysis of Low Layer Density Multilayer Insulation Test Results

    Science.gov (United States)

    Johnson, Wesley L.

    2011-01-01

    Investigation of the thermal performance of low layer density multilayer insulations is important for designing long-duration space exploration missions involving the storage of cryogenic propellants. Theoretical calculations show an analytical optimal layer density, as widely reported in the literature. However, the appropriate test data by which to evaluate these calculations have been only recently obtained. As part of a recent research project, NASA procured several multilayer insulation test coupons for calorimeter testing. These coupons were configured to allow for the layer density to be varied from 0.5 to 2.6 layer/mm. The coupon testing was completed using the cylindrical Cryostat-l00 apparatus by the Cryogenics Test Laboratory at Kennedy Space Center. The results show the properties of the insulation as a function of layer density for multiple points. Overlaying these new results with data from the literature reveals a minimum layer density; however, the value is higher than predicted. Additionally, the data show that the transition region between high vacuum and no vacuum is dependent on the spacing of the reflective layers. Historically this spacing has not been taken into account as thermal performance was calculated as a function of pressure and temperature only; however the recent testing shows that the data is dependent on the Knudsen number which takes into account pressure, temperature, and layer spacing. These results aid in the understanding of the performance parameters of MLI and help to complete the body of literature on the topic.

  18. THERMAL INSULATION FROM LIGNIN-DERIVED CARBON FIBERS

    Energy Technology Data Exchange (ETDEWEB)

    Albers, Tracy [GrafTech International; Chen, Chong [GrafTech International; Eberle, Cliff [ORNL; Webb, Daniel C [ORNL

    2014-01-01

    Oak Ridge National Laboratory (ORNL) and GrafTech International Holdings Inc. (GrafTech) have collaborated to develop and demonstrate the performance of high temperature thermal insulation prototypes made from lignin-based carbon fibers (LBCF). This was the first reported production of LBCF or resulting products at scale > 1 kg. The results will potentially lead to the first commercial application of LBCF. The goal of the commercial application is to replace expensive, foreign-sourced isotropic pitch carbon fibers with lower cost carbon fibers made from a domestically sourced, bio-derived (renewable) feedstock. LBCF can help resolve supply chain vulnerability and reduce the production cost for high temperature thermal insulation as well as create US jobs. The performance of the LBCF prototypes was measured and found to be comparable to that of the current commercial product. During production of the insulation prototypes, the project team demonstrated lignin compounding/pelletization, fiber production, heat treatment, and compositing at scales far surpassing those previously demonstrated in LBCF R&D or production.

  19. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

  20. Comparison of Dissolved Gases in Mineral and Vegetable Insulating Oils under Typical Electrical and Thermal Faults

    OpenAIRE

    Chenmeng Xiang; Quan Zhou; Jian Li; Qingdan Huang; Haoyong Song; Zhaotao Zhang

    2016-01-01

    Dissolved gas analysis (DGA) is attracting greater and greater interest from researchers as a fault diagnostic tool for power transformers filled with vegetable insulating oils. This paper presents experimental results of dissolved gases in insulating oils under typical electrical and thermal faults in transformers. The tests covered three types of insulating oils, including two types of vegetable oil, which are camellia insulating oil, Envirotemp FR3, and a type of mineral insulating oil, to...

  1. Thermal insulating concrete wall panel design for sustainable built environment.

    Science.gov (United States)

    Zhou, Ao; Wong, Kwun-Wah; Lau, Denvid

    2014-01-01

    Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes.

  2. Low-Density, Aerogel-Filled Thermal-Insulation Tiles

    Science.gov (United States)

    Santos, Maryann; Heng, Vann; Barney, Andrea; Oka, Kris; Droege, Michael

    2005-01-01

    Aerogel fillings have been investigated in a continuing effort to develop low-density thermal-insulation tiles that, relative to prior such tiles, have greater dimensional stability (especially less shrinkage), equal or lower thermal conductivity, and greater strength and durability. In preparation for laboratory tests of dimensional and thermal stability, prototypes of aerogel-filled versions of recently developed low-density tiles have been fabricated by impregnating such tiles to various depths with aerogel formations ranging in density from 1.5 to 5.6 lb/ft3 (about 53 to 200 kg/cu m). Results available at the time of reporting the information for this article showed that the thermal-insulation properties of the partially or fully aerogel- impregnated tiles were equivalent or superior to those of the corresponding non-impregnated tiles and that the partially impregnated tiles exhibited minimal (<1.5 percent) shrinkage after multiple exposures at a temperature of 2,300 F (1,260 C). Latest developments have shown that tiles containing aerogels at the higher end of the density range are stable after multiple exposures at the said temperature.

  3. Thermal Insulating Concrete Wall Panel Design for Sustainable Built Environment

    Directory of Open Access Journals (Sweden)

    Ao Zhou

    2014-01-01

    Full Text Available Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes.

  4. Thermal Insulating Concrete Wall Panel Design for Sustainable Built Environment

    Science.gov (United States)

    Zhou, Ao; Wong, Kwun-Wah

    2014-01-01

    Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes. PMID:25177718

  5. Sprayable Aerogel Bead Compositions With High Shear Flow Resistance and High Thermal Insulation Value

    Science.gov (United States)

    Ou, Danny; Trifu, Roxana; Caggiano, Gregory

    2013-01-01

    A sprayable aerogel insulation has been developed that has good mechanical integrity and lower thermal conductivity than incumbent polyurethane spray-on foam insulation, at similar or lower areal densities, to prevent insulation cracking and debonding in an effort to eliminate the generation of inflight debris. This new, lightweight aerogel under bead form can be used as insulation in various thermal management systems that require low mass and volume, such as cryogenic storage tanks, pipelines, space platforms, and launch vehicles.

  6. Dynamic clothing insulation. Measurements with a thermal manikin operating under the thermal comfort regulation mode.

    Science.gov (United States)

    Oliveira, A Virgílio M; Gaspar, Adélio R; Quintela, Divo A

    2011-11-01

    The main objective of the present work is the assessment of the thermal insulation of clothing ensembles, both in static conditions and considering the effect of body movements. The different equations used to calculate the equivalent thermal resistance of the whole body, namely the serial, the global and the parallel methods, are considered and the results are presented and discussed for the basic, the effective and the total clothing insulations. The results show that the dynamic thermal insulation values are always lower than the corresponding static ones. The highest mean relative difference [(static-dynamic)/static] was obtained with the parallel method and the lowest with the serial. For I(cl) the mean relative differences varied from 0.5 to 13.4% with the serial method, from 5.6 to 14.6% with the global and from 7.2 to 17.7% with the parallel method. In addition, the dynamic tests presents the higher mean relative differences between the calculation methods. The results also show that the serial method always presents the higher values and the parallel method the lowest ones. The relative differences between the calculation methods {[(serial-global)/global] and [(parallel-global)/global]} were sometimes significant and associated to the non-uniform distribution of the clothing insulation. In fact, the ensembles with the highest thermal insulation values present the highest differences between the calculation methods. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  7. Nanoporous Carbon Monoliths with Tunable Thermal Insulation and Mechanical Properties.

    Science.gov (United States)

    Wang, Xiaopeng; Chen, Fenghua; Luo, Zhenhua; Li, Hao; Zhao, Tong

    2016-01-01

    In this work, nanoscale porous carbon monoliths, with excellent compressive strength and thermal insulation, were obtained with a simple method of carbonizing cured phenol-formaldehyde resin/poly(methyl methacrylate) blends. Apparent density, pore size and morphology of the carbon monoliths were tailored by changing the composition, curing process and carbonization temperature. The continuous nanopores played a key role in enhancing mechanical and thermal performance of the carbon materials. When PMMA concentration was 25%, apparent density and thermal conductivity of the nanoporous carbonaceous monoliths were obtained as low as 1.07 g · cm⁻³ and 0.42 W/(m · K), decreasing by 29.4% and 35.4% than that of carbonaceous monoliths obtained from pure PF; while compressive strength of the nanoporous carbonaceous monoliths was as high as 34 MPa, which was improved over five times than that of pure PF carbon monoliths.

  8. Performance of sealed evacuated panels as thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    Brodt, K.H.; Bart, G.C.J. (Technische Hogeschool Delft (Netherlands))

    1994-05-01

    The CFC-blown polyurethane foam currently used as thermal insulation will be banned in the future because of the environmental impact of chlorofluorocarbons. This requires the use of other blowing agents, which often do not possess the same low thermal conductivity as, for example, CFC11. Evacuated panels avoid these environmental problems and can possesses lower conductivity than rigid foams. It is believed that they are a promising option in spite of the major problem of maintaining the vacuum for a decade or longer. They require: (a) a leak-free sealing and a covering with an extremely low gas permeability; (b) a low and stable inner pressure; (c) an infra-red absorbing filler which withstands outside pressure. The foils used for sealing these panels will influence the overall thermal conductivity, especially if they are, for reason of vacuum tightness, metal coated. (Author)

  9. A Thermally Insulating Textile Inspired by Polar Bear Hair.

    Science.gov (United States)

    Cui, Ying; Gong, Huaxin; Wang, Yujie; Li, Dewen; Bai, Hao

    2018-02-14

    Animals living in the extremely cold environment, such as polar bears, have shown amazing capability to keep warm, benefiting from their hollow hairs. Mimicking such a strategy in synthetic fibers would stimulate smart textiles for efficient personal thermal management, which plays an important role in preventing heat loss and improving efficiency in house warming energy consumption. Here, a "freeze-spinning" technique is used to realize continuous and large-scale fabrication of fibers with aligned porous structure, mimicking polar bear hairs, which is difficult to achieve by other methods. A textile woven with such biomimetic fibers shows an excellent thermal insulation property as well as good breathability and wearability. In addition to passively insulating heat loss, the textile can also function as a wearable heater, when doped with electroheating materials such as carbon nanotubes, to induce fast thermal response and uniform electroheating while maintaining its soft and porous nature for comfortable wearing. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Analysis of thermal performance of penetrated multi-layer insulation

    Science.gov (United States)

    Foster, Winfred A., Jr.; Jenkins, Rhonald M.; Yoo, Chai H.; Barrett, William E.

    1988-01-01

    Results of research performed for the purpose of studying the sensitivity of multi-layer insulation blanket performance caused by penetrations through the blanket are presented. The work described in this paper presents the experimental data obtained from thermal vacuum tests of various penetration geometries similar to those present on the Hubble Space Telescope. The data obtained from these tests is presented in terms of electrical power required sensitivity factors referenced to a multi-layer blanket without a penetration. The results of these experiments indicate that a significant increase in electrical power is required to overcome the radiation heat losses in the vicinity of the penetrations.

  11. Study of thermal insulation for airborne liquid hydrogen fuel tanks

    Science.gov (United States)

    Ruccia, F. E.; Lindstrom, R. S.; Lucas, R. M.

    1978-01-01

    A concept for a fail-safe thermal protection system was developed. From screening tests, approximately 30 foams, adhesives, and reinforcing fibers using 0.3-meter square liquid nitrogen cold plate, CPR 452 and Stafoam AA1602, both reinforced with 10 percent by weight of 1/16 inch milled OCF Style 701 Fiberglas, were selected for further tests. Cyclic tests with these materials in 2-inch thicknesses bonded on a 0.6-meter square cold plate with Crest 7410 adhesive systems, were successful. Zero permeability gas barriers were identified and found to be compatible with the insulating concept.

  12. Enhanced RF Behavior Multi-Layer Thermal Insulation.

    Science.gov (United States)

    Mazzinghi, A; Sabbadini, M; Freni, A

    2018-01-08

    This paper shows that it is possible to exploit the modulated metasurface concept to control the unwanted coupling between antennas that are installed on the same satellite. The metasurface is combined with a Multi-Layer thermal Insulation blanket to reduce its specular reflection by spreading the energy incoherently in the surrounding space. In the design, sub-wavelength radiating elements printed on thin substrate have been used to make the metasurface response azimuthally independent, and to keep the weight of blanket down. The comparison between simulations and measurements confirms the validity of the idea.

  13. Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation

    OpenAIRE

    Fan, Bitao; Chen, Shujun; Yao, Qiufang; Sun, Qingfeng; Jin, Chunde

    2017-01-01

    Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation propertie...

  14. Load Responsive MLI: Thermal Insulation with High In-Atmosphere and On-Orbit Performance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight, high performance thermal insulation is critical to NASA's next generation Exploration spacecraft. Zero or low cryogenic propellant boiloff is required...

  15. Radiation Abating Highly Flexible Multifunctional Polyimide Cryogenic and Thermal Insulation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of highly flexible thermal insulation materials with multifunctional properties based in polyimide polymers and designed to provide significant...

  16. Integrated MLI: Advanced Thermal Insulation Using Micro-Molding Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight, high performance thermal insulation is critical to NASA's next generation Exploration spacecraft. Zero or low cryogenic propellant boiloff is required...

  17. Applying infrared measurements in a measuring system for determining thermal parameters of thermal insulation materials

    Science.gov (United States)

    Chudzik, S.

    2017-03-01

    The paper presents results of research on an innovative method for determining thermal parameters of thermal insulating materials. The method is based on harmonic thermal excitations. Temperature measurements at selected points of a specimen under test are performed by means of semiconductor infrared sensors. The study also employs a 3D model of thermal diffusion. To obtain a solution of the coefficient inverse problem a method based on an artificial neural network is presented. The heat transfer coefficient on the specimen surface is estimated on the basis of a reference specimen. The validity of the adopted model of heat diffusion and the usefulness of the method proposed are verified experimentally.

  18. Thermal Performance of Cryogenic Multilayer Insulation at Various Layer Spacings

    Science.gov (United States)

    Johnson, Wesley Louis

    2010-01-01

    Multilayer insulation (MLI) has been shown to be the best performing cryogenic insulation system at high vacuum (less that 10 (exp 3) torr), and is widely used on spaceflight vehicles. Over the past 50 years, many investigations into MLI have yielded a general understanding of the many variables that are associated with MLI. MLI has been shown to be a function of variables such as warm boundary temperature, the number of reflector layers, and the spacer material in between reflectors, the interstitial gas pressure and the interstitial gas. Since the conduction between reflectors increases with the thickness of the spacer material, yet the radiation heat transfer is inversely proportional to the number of layers, it stands to reason that the thermal performance of MLI is a function of the number of layers per thickness, or layer density. Empirical equations that were derived based on some of the early tests showed that the conduction term was proportional to the layer density to a power. This power depended on the material combination and was determined by empirical test data. Many authors have graphically shown such optimal layer density, but none have provided any data at such low densities, or any method of determining this density. Keller, Cunnington, and Glassford showed MLI thermal performance as a function of layer density of high layer densities, but they didn't show a minimal layer density or any data below the supposed optimal layer density. However, it was recently discovered that by manipulating the derived empirical equations and taking a derivative with respect to layer density yields a solution for on optimal layer density. Various manufacturers have begun manufacturing MLI at densities below the optimal density. They began this based on the theory that increasing the distance between layers lowered the conductive heat transfer and they had no limitations on volume. By modifying the circumference of these blankets, the layer density can easily be

  19. SIMULATION OF THERMAL DECOMPOSITION OF MINERAL INSULATING OIL

    Directory of Open Access Journals (Sweden)

    V. G. M. Cruz

    2015-09-01

    Full Text Available AbstractDissolved gas analysis (DGA has been applied for decades as the main predictive maintenance technique for diagnosing incipient faults in power transformers since the decomposition of the mineral insulating oil (MIO produces gases that remain dissolved in the liquid phase. Nevertheless, the most known diagnostic methods are based on findings of simplified thermodynamic and compositional models for the thermal decomposition of MIO, in addition to empirical data. The simulation results obtained from these models do not satisfactorily reproduce the empirical data. This paper proposes a flexible thermodynamic model enhanced with a kinetic approach and selects, among four compositional models, the one offering the best performance for the simulation of thermal decomposition of MIO. The simulation results obtained from the proposed model showed better adequacy to reported data than the results obtained from the classical models. The proposed models may be applied in the development of a phenomenologically-based diagnostic method.

  20. Thermal insulation. Non-utilized energy need not be generated. Four rules for a successful thermal insulation by means of building insulation; Waermedaemmung. Energie, die nicht gebraucht wird, muss man nicht erzeugen. Vier Regeln fuer erfolgreichen Waermeschutz durch Gebaeudedaemmung

    Energy Technology Data Exchange (ETDEWEB)

    Patschke, Markus [3E-Consult, Nordkirchen (Germany); Drewer, Arnold [IpeG-Institut, Paderborn (Germany)

    2011-07-15

    The heat supply of buildings causes nearly one third of the energy consumption of an industrialized country. In 2006, the climate-adjusted heat consumption of private households in Germany amounted nearly 600 billion kWh. This consumption caused more than 167 million tons of CO{sub 2}. Heat insulation measures in buildings are required for all heat-transferring enveloping surface. Under this aspect, the contribution under consideration reports on four fundamental rules for a cost-efficient building insulation: (a) Only heated rooms should be insulated thermally; (b) Location and thermal insulation of cavities; (c) Selection of a suitable insulating material; (d) Consideration of an economic sustainability.

  1. Clothing resultant thermal insulation determined on a movable thermal manikin. Part I: effects of wind and body movement on total insulation.

    Science.gov (United States)

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Shi, Wen; Zhang, Chengjiao

    2015-10-01

    In this serial study, 486 thermal manikin tests were carried out to examine the effects of air velocity and walking speed on both total and local clothing thermal insulations. Seventeen clothing ensembles with different layers (i.e., one, two, or three layers) were selected for the study. Three different wind speeds (0.15, 1.55, 4.0 m/s) and three levels of walking speed (0, 0.75, 1.2 m/s) were chosen. Thus, there are totally nine different testing conditions. The clothing total insulation and local clothing insulation at different body parts under those nine conditions were determined. In part I, empirical equations for estimating total resultant clothing insulation as a function of the static thermal insulation, relative air velocity, and walking speed were developed. In part II, the local thermal insulation of various garments was analyzed and correction equations on local resultant insulation for each body part were developed. This study provides critical database for potential applications in thermal comfort study, modeling of human thermal strain, and functional clothing design and engineering.

  2. High performance thermal insulation systems (HiPTI). Vacuum insulated products (VIP). Proceedings of the international conference and workshop

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, M.; Bertschinger, H.

    2001-07-01

    These are the proceedings of the International Conference and Workshop held at EMPA Duebendorf, Switzerland, in January 2001. The papers presented at the conference's first day included contributions on the role of high-performance insulation in energy efficiency - providing an overview of available technologies and reviewing physical aspects of heat transfer and the development of thermal insulation as well as the state of the art of glazing technologies such as high-performance and vacuum glazing. Also, vacuum-insulated products (VIP) with fumed silica, applications of VIP systems in technical building systems, nanogels, VIP packaging materials and technologies, measurement of physical properties, VIP for advanced retrofit solutions for buildings and existing and future applications for advanced low energy building are discussed. Finally, research and development concerning VIP for buildings are reported on. The workshops held on the second day covered a preliminary study on high-performance thermal insulation materials with gastight porosity, flexible pipes with high performance thermal insulation, evaluation of modern insulation systems by simulation methods as well as the development of vacuum insulation panels with a stainless steel envelope.

  3. Cryogenic Shrouds for Testing Thermal-Insulation Panels

    Science.gov (United States)

    Norris, Jeffrey; Carroll, Robert; Kirch, Charles

    2007-01-01

    Cryogenic shrouds have been designed and built for use in thermomechanical testing of samples of thermalinsulation panels on cryogenic vessels. In the original application for which these shrouds were specifically designed, the samples are representative of the large-area thermal-insulation panels on the space-shuttle external tanks that hold liquid hydrogen and liquid oxygen, and the purpose of the testing is to demonstrate the ability of bonded layers in the panels to resist delamination under a combination of applied uniaxial mechanical loads and realistic operational temperatures. Presumably, the shrouds and the tests performed by use of them could be modified to enable similar evaluation of thermomechanical properties of thermal-insulation panels for cryogenic vessels other than the external tanks of the space shuttles. The shrouds are required to enable maintenance of required temperatures on the inner and outer surfaces of the thermal-insulation-panel samples, to enable visual observation of the outer surfaces of the samples, and not to introduce any measurable loads into the panels. For each panel sample, there are two shrouds: one to be mounted on the inner surface (the surface that would be in contact with a tank containing a cryogenic liquid during normal use) and one to be mounted on the outer surface (the surface that would be exposed to ambient air or other warmer environment during normal use). The shrouds for testing specimens of thermal-insulation- panels for the liquid-hydrogen tank are made largely of titanium; the shrouds for testing specimens of thermal- insulation-panels for the liquid-oxygen tank are made largely of an aluminum- lithium alloy. The specific temperature requirements are the following: The inner shroud must make it possible to maintain a temperature of 321 degrees F (196 degrees C) [the approximate temperature of liquid nitrogen] or 453 F (about 269 C) [the approximate temperature of liquid helium] on the inner face of the

  4. Thermal-performance study of liquid metal fast breeder reactor insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shiu, Kelvin K.

    1980-09-01

    Three types of metallic thermal insulation were investigated analytically and experimentally: multilayer reflective plates, multilayer honeycomb composite, and multilayer screens. Each type was subjected to evacuated and nonevacuated conditions, where thermal measurements were made to determine thermal-physical characteristics. A variation of the separation distance between adjacent reflective plates of multilayer reflective plates and multilayer screen insulation was also experimentally studied to reveal its significance. One configuration of the multilayer screen insulation was further selected to be examined in sodium and sodium oxide environments. The emissivity of Type 304 stainless steel used in comprising the insulation was measured by employing infrared technology. A comprehensive model was developed to describe the different proposed types of thermal insulation. Various modes of heat transfer inherent in each type of insulation were addressed and their relative importance compared. Provision was also made in the model to allow accurate simulation of possible sodium and sodium oxide contamination of the insulation. The thermal-radiation contribution to heat transfer in the temperature range of interest for LMFBR's was found to be moderate, and the suppression of natural convection within the insulation was vital in preserving its insulating properties. Experimental data were compared with the model and other published results. Moreover, the three proposed test samples were assessed and compared under various conditions as viable LMFBR thermal insulations.

  5. Standard Practice for Evaluating Thermal Insulation Materials for Use in Solar Collectors

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This practice sets forth a testing methodology for evaluating the properties of thermal insulation materials to be used in solar collectors with concentration ratios of less than 10. Tests are given herein to evaluate the pH, surface burning characteristics, moisture adsorption, water absorption, thermal resistance, linear shrinkage (or expansion), hot surface performance, and accelerated aging. This practice provides a test for surface burning characteristics but does not provide a methodology for determining combustibility performance of thermal insulation materials. 1.2 The tests shall apply to blanket, rigid board, loose-fill, and foam thermal insulation materials used in solar collectors. Other thermal insulation materials shall be tested in accordance with the provisions set forth herein and should not be excluded from consideration. 1.3 The assumption is made that elevated temperature, moisture, and applied stresses are the primary factors contributing to the degradation of thermal insulation mat...

  6. A Network Model for the Effective Thermal Conductivity of Rigid Fibrous Refractory Insulations

    Science.gov (United States)

    Marschall, Jochen; Cooper, D. M. (Technical Monitor)

    1995-01-01

    A procedure is described for computing the effective thermal conductivity of a rigid fibrous refractory insulation. The insulation is modeled as a 3-dimensional Cartesian network of thermal conductance. The values and volume distributions of the conductance are assigned to reflect the physical properties of the insulation, its constituent fibers, and any permeating gas. The effective thermal conductivity is computed by considering the simultaneous energy transport by solid conduction, gas conduction and radiation through a cubic volume of model insulation; thus the coupling between heat transfer modes is retained (within the simplifications inherent to the model), rather than suppressed by treating these heat transfer modes as independent. The model takes into account insulation composition, density and fiber anisotropy, as well as the geometric and material properties of the constituent fibers. A relatively good agreement, between calculated and experimentally derived thermal conductivity values, is obtained for a variety of rigid fibrous insulations.

  7. Thermal Insulating Properties of Straw-Filled Environmentally Friendly Building Materials

    Science.gov (United States)

    Petkova-Slipets, Rositsa; Zlateva, Penka

    2017-06-01

    The paper presents results of a research for determination of a few general thermal-physical properties of environmentally friendly building materials made by clay, sand and straw. The aim of this study is to establish their heat insulating and energy-efficient capacity. All specific measurements were carried out by using the newest generation thermal conductivity analyser Mathis TCi. The results showed that the studied composite materials are good thermal insulators with thermal conductivity less than 0.5 W/m.K, which depends on the straw amount. Even less than 0.5 wt.% straw reflects on the insulating properties by decreasing the thermal conductivity coefficient with nearly 50 %.

  8. Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

    Directory of Open Access Journals (Sweden)

    Kirpluks Mikelis

    2014-12-01

    Full Text Available 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.

  9. Apparatus for Testing Flat Specimens of Thermal Insulation

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stanislaw D.

    2005-01-01

    An apparatus has been developed to implement an improved method of testing flat-plate specimens of thermal-insulation materials for cryogenic application. The method includes testing under realistic use conditions that could include vacuum and mechanical loading at a pressure up to 70 psi (=0.48 MPa). The apparatus can accommodate a rigid or flexible specimen having thickness up to 1.25 in. (=3.2 cm) and diameters between 6 and 10 in. (about 15.2 and 25.4 cm, respectively). Typical test conditions include boundary temperatures between 77 K and 373 K and vacuum/interstitial gas filling at a pressure between 10(exp -6) torr (=1.3 x 10(exp -4) Pa) and 760 torr (atmospheric pressure =0.1 MPa). The interstitial gas could be N2, He, CO2, or any other suitable gas to which the insulation is expected to be exposed in use. Relative to prior apparatuses and testing methods, this apparatus and the testing method that it implements offer advantages of relative simplicity and ease of use. The basic principle of operation of the apparatus is that of boil-off calorimetry, using liquid nitrogen or any other suitable liquid that boils at a desired temperature below ambient temperature. Comparative rates of flow of heat through the thicknesses of the specimens (heat-leak rates) and apparent-thermal-conductivity values are obtained from tests of specimens. Absolute values of heat-leak rates and apparent thermal conductivities are computed from a combination of (1) the aforementioned comparative values and (2) calibration factors obtained by testing reference specimens of materials that have known thermal-insulation properties. The apparatus includes a full complement of temperature sensors, a vacuum pump and chamber, a monitoring and control system, and tools and fixtures that enable rapid and reliable installation and removal of specimens. A specimen is installed at the bottom of the vacuum chamber, and a cold-mass assembly that includes a tank is lowered into position above and

  10. Arranging insulation for better thermal resistance in concrete and maonry wall systems

    OpenAIRE

    Urban, B; P. Engelmann; Kossecka, E.; Kosny, J.

    2011-01-01

    This paper investigates how the spatial arrangement of thermal insulation influences the overall thermal resistance of concrete and masonry wall systems. Multi-dimensional finite difference modeling was used for this purpose. Concrete masonry units (CMUs) are commercially produced in various geometries and with different weight concretes. Although insulation inserts can increase a CMUs thermal performance, thermal bridging through the solid webbing of the CMUs can greatly reduce the effective...

  11. Construction method of foam glass thermal insulation material in sloping roof

    Science.gov (United States)

    Hu, Longwei; Bu, Fangming; Guo, Fenglu; Zhang, Zimeng

    2017-04-01

    Foam glass thermal insulation board has the characteristics of fireproof, waterproof, corrosion resistant, noncombustible, mothproof, non-toxic, non-aging, non-radioactive, high mechanical strength and good dimensional stability. Foam glass thermal insulation material in sloping roof construction method is an effective solution to large angle sloping roof construction operation difficulties.

  12. Hemp Thermal Insulation Concrete with Alternative Binders, Analysis of their Thermal and Mechanical Properties

    Science.gov (United States)

    Sinka, M.; Sahmenko, G.; Korjakins, A.; Radina, L.; Bajare, D.

    2015-11-01

    One of the main challenges that construction industry faces today is how to address the demands for more sustainable, environmentally friendly and carbon neutral construction materials and building upkeep processes. One of the answers to these demands is lime-hemp concrete (LHC) building materials - carbon negative materials that have sufficient thermal insulation capabilities to be used as thermal insulation materials for new as well as for existing buildings. But one problem needs to be overcome before these materials can be used on a large scale - current manufacturing technology allows these materials to be used only as self-bearing thermal insulation material with large labour intensity in the manufacturing process. In order to lower the labour intensity and allow the material to be used in wider applications, a LHC block and board production is necessary, which in turn calls for the binders different from the classically used ones, as they show insufficient mechanical strength for this new use. The particular study focuses on alternative binders produced using gypsum-cement compositions ensuring they are usable in outdoor applications together with hemp shives. Physical, mechanical, thermal and water absorption properties of hemp concrete with various binders are addressed in the current study.

  13. Thermal Insulation System for Non-Vacuum Applications Including a Multilayer Composite

    Science.gov (United States)

    Fesmire, James E. (Inventor)

    2017-01-01

    The thermal insulation system of the present invention is for non-vacuum applications and is specifically tailored to the ambient pressure environment with any level of humidity or moisture. The thermal insulation system includes a multilayered composite including i) at least one thermal insulation layer and at least one compressible barrier layer provided as alternating, successive layers, and ii) at least one reflective film provided on at least one surface of the thermal insulation layer and/or said compressible barrier layer. The different layers and materials and their combinations are designed to provide low effective thermal conductivity for the system by managing all modes of heat transfer. The thermal insulation system includes an optional outer casing surrounding the multilayered composite. The thermal insulation system is particularly suited for use in any sub-ambient temperature environment where moisture or its adverse effects are a concern. The thermal insulation system provides physical resilience against damaging mechanical effects including compression, flexure, impact, vibration, and thermal expansion/contraction.

  14. Economical analysis of determination thermal insulation thickness for different external walls

    Directory of Open Access Journals (Sweden)

    Ali Etem Gürel

    2011-06-01

    Full Text Available In the countries which supply big amount of their energy needs by import like Turkey using the energy economically is important. Thermal insulation technologies in buildings are the main method for using energy economically. But choosing the thickness of the insulation material redundant causes high insulation costs. For this reason, an optimum point which provides the highest price in insulation applications is the subject. In this study, different building materials (horizontal perforated brick and gas concrete, and isolated forms of insulation (exterior insulation and insulation sandwich was a model of a building exterior wall. The study determined that the wall and the heat loss through the life-cost analysis, according to the present calculations (LCCA, the optimum thickness of insulation, energy savings and payback periods were determined.

  15. Polyimide-Foam/Aerogel Composites for Thermal Insulation

    Science.gov (United States)

    Williams, Martha; Fesmire, James; Sass, Jared; Smith, Trent; Weoser. Erol

    2009-01-01

    Composites of specific types of polymer foams and aerogel particles or blankets have been proposed to obtain thermal insulation performance superior to those of the neat polyimide foams. These composites have potential to also provide enhanced properties for vibration dampening or acoustic attenuation. The specific type of polymer foam is denoted "TEEK-H", signifying a series, denoted H, within a family of polyimide foams that were developed at NASA s Langley Research Center and are collectively denoted TEEK (an acronym of the inventors names). The specific types of aerogels include Nanogel aerogel particles from Cabot Corporation in Billerica, MA. and of Spaceloft aerogel blanket from Aspen Aerogels in Northborough, MA. The composites are inherently flame-retardant and exceptionally thermally stable. There are numerous potential uses for these composites, at temperatures from cryogenic to high temperatures, in diverse applications that include aerospace vehicles, aircraft, ocean vessels, buildings, and industrial process equipment. Some low-temperature applications, for example, include cryogenic storage and transfer or the transport of foods, medicines, and chemicals. Because of thermal cycling, aging, and weathering most polymer foams do not perform well at cryogenic temperatures and will undergo further cracking over time. The TEEK polyimides are among the few exceptions to this pattern, and the proposed composites are intended to have all the desirable properties of TEEK-H foams, plus improved thermal performance along with enhanced vibration or acoustic-attenuation performance. A composite panel as proposed would be fabricated by adding an appropriate amount of TEEK friable balloons into a mold to form a bottom layer. A piece of flexible aerogel blanket material, cut to the desired size and shape, would then be placed on the bottom TEEK layer and sandwiched between another top layer of polyimide friable balloons so that the aerogel blanket would become

  16. THERMAL CONDUCTIVITY OF THE REGENERATION WASTE TEXTILES USED TO THERMAL INSULATION

    OpenAIRE

    Gheorghe Horga; Mihaela Horga; Ioan Hossu; Dorin Avram; Florin Breaban

    2013-01-01

    This paper presents theoretical and experimental studies on the behavior thermal conductivity of textiles made from regeneration fiber used to make the shells for insulation of pipelines. Was investigated the behavior of textile fibers regeneration at densities, temperatures and different layer thickness, in two structures: material in the form of fibers in the form of flock, named blanket and textile material in the form of fiber layer consolidated named, no woven material.Measurements were ...

  17. Preparation and performance of thermal insulation energy saving coating materials for exterior wall.

    Science.gov (United States)

    Wang, Fei; Liang, Jinsheng; Tang, Qingguo; Chen, Gong; Chen, Yalei

    2014-05-01

    Nano zinc oxide with a high refractive index has good thermal reflection performance, hollow glass microspheres have good thermal reflection and insulation performance, and sepiolite nanofibers with many nanostructural pores have good thermal insulation performance. The dispensability of nano zinc oxide in coating materials was improved by optimizing surface silane coupling agent modification process, leading to the good thermal reflection performance. The thermal insulation performance was improved by hollow glass microspheres and sepiolite nanofibers. On this basis, the thermal insulation coating materials were prepared by exploring the effect of amount, complex mode, and other factors of the above three kinds of functional fillers on the thermal reflection and insulation performance of coating materials. The results showed that the surface modification effect of nano zinc oxide was the best when the silane coupling agent addition was 6%. The reflection and insulation performance of the coatings were the best when the additions of modified nano zinc oxide, hollow glass microspheres, and sepiolite nanofibers were 3%, 4%, and 4%, respectively. Compared with the control coating materials, the thermal insulation effect was improved obviously, which was evaluated by the -13.5 degrees C increase of maximum temperature difference between the upper and the lower surfaces.

  18. Thermally Insulated Flexible Composite Cores for Aerospace Applications

    National Research Council Canada - National Science Library

    Johnson, William

    1998-01-01

    IMP has developed a very unusual and unique flexible ceramic insulation. The original research was oriented toward the incorporation of an insulation material into the open cells of a honeycomb core inside a CFRP composite sandwich...

  19. The relationship between thermal environments and clothing insulation for elderly individuals in Shanghai, China.

    Science.gov (United States)

    Jiao, Yu; Yu, Hang; Wang, Tian; An, Yusong; Yu, Yifan

    2017-12-01

    The relationship between thermal environmental parameters and clothing insulation is an important element in improving thermal comfort for the elderly. A field study was conducted on the indoor, transition space, and outdoor thermal environments of 17 elderly facilities in Shanghai, China. A random questionnaire survey was used to gather data from 672 valid samples. A statistical analysis of the data was conducted, and multiple linear regression models were established to quantify the relationships between clothing insulation, respondent age, indoor air temperature, and indoor relative humidity. Results indicated that the average thermal insulation of winter and summer clothing is 1.38 clo and 0.44 clo, respectively, for elderly men and 1.39 clo and 0.45 clo, respectively, for elderly women. It was also found that the thermal insulation of winter clothing is linearly correlated with age, and that there were seasonal differences in the relationship between clothing insulation and the environment. During winter, the clothing insulation is negatively correlated only with indoor temperature parameters (air temperature and operative temperature) for elderly males, while it is negatively correlated with indoor temperature parameters as well as transition space and outdoor air temperature for elderly females. In summer, clothing insulation for both elderly males and females is negatively correlated with outdoor temperature, as well as indoor temperature parameters (air temperature and operative temperature). The thermal insulation of summer clothing is also negatively correlated with transitional space temperature for males. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Thermal insulation, antibacterial and mold properties of breathable nanofiber-laminated wallpapers.

    Science.gov (United States)

    Kim, Byoung-Suhk; Kimura, Naotaka; Kim, Han-Ki; Watanabe, Kei; Kim, Ick-Soo

    2011-06-01

    We studied the thermal insulation, antibacterial and mold properties of the nanofiber laminated wallpapers prepared by laminate-coating using electrospinning method. The thermal insulation capability of the nanofiber laminated wallpapers was evaluated by using a home-made insulated environmental chamber under different environmental conditions. It was found that the nanofiber laminated wallpapers exhibited better thermal insulation performance than the conventional silk wallpaper, which was commercialized silk wallpapers prepared by polyacrylic resin, suggesting that the laminate-coated nanofiber layer played an effective role in thermal insulation. Compared to the normal silk wallpaper, the nanofiber laminated wallpaper also exhibited good moisture vapor transmission rate (MVTR) due to excellent vapor permeability. In addition, TiO2-containing nanofiber laminated wallpapers exhibited good antibacterial activity against both E. Coli and P. Aeruginosa.

  1. Structural analysis of a thermal insulation retainer assembly

    Science.gov (United States)

    Greene, William H.; Gray, Carl E., Jr.

    1989-01-01

    In January 1989 an accident occurred in the National Transonic Facility wind tunnel at NASA Langley Research Center that was believed to be caused by the failure of a thermal insulation retainer. A structural analysis of this retainer assembly was performed in order to understand the possible failure mechanisms. Two loading conditions are important and were considered in the analysis. The first is the centrifugal force due to the fact that this retainer is located on the fan drive shaft. The second loading is a differential temperature between the retainer assembly and the underlying shaft. Geometrically nonlinear analysis is required to predict the stiffness of this component and to account for varying contact regions between various components in the assembly. High, local stresses develop in the band part of the assembly near discontinuities under both the centrifugal and thermal loadings. The presence of an aluminum ring during a portion of the part's operating life was found to increase the stresses in other regions of the band. Under the centrifugal load, high bending stresses develop near the intersection of the band with joints in the assembly. These high bending stresses are believed to be the most likely cause for failure of the assembly.

  2. A Facile Approach to Evaluate Thermal Insulation Performance of Paper Cups

    OpenAIRE

    Yudi Kuang; Gang Chen; Zhiqiang Fang

    2015-01-01

    Paper cups are ubiquitous in daily life for serving water, soup, coffee, tea, and milk due to their convenience, biodegradability, recyclability, and sustainability. The thermal insulation performance of paper cups is of significance because they are used to supply hot food or drinks. Using an effective thermal conductivity to accurately evaluate the thermal insulation performance of paper cups is complex due to the inclusion of complicated components and a multilayer structure. Moreover, an ...

  3. Thermal response of rigid and flexible insulations and reflective coating in an aeroconvective heating environment

    Science.gov (United States)

    Kourtides, D. A.; Chiu, S. A.; Iverson, D. J.; Lowe, D. M.

    1992-01-01

    Described here is the thermal performance of rigid and flexible thermal protection systems considered for potential use in future Aeroassist Space Transfer Vehicles. The thermal response of these materials subjected to aeroconvective heating from a plasma arc is described. Properties that were measured included the thermal conductivity of both rigid and flexible insulations at various temperatures and pressures and the emissivity of the fabrics used in the flexible insulations. The results from computerized thermal analysis models describing the thermal response of these materials subjected to flight conditions are included.

  4. Thermal spray coating for corrosion under insulation (CUI) prevention

    Science.gov (United States)

    Fuad, Mohd Fazril Irfan Ahmad; Razak, Khalil Abdul; Alias, Nur Hashimah; Othman, Nur Hidayati; Lah, Nik Khairul Irfan Nik Ab

    2017-12-01

    Corrosion under insulation (CUI) is one of the predominant issues affecting process of Oil and Gas and Petrochemical industries. CUI refers to external corrosion, but it is difficult to be detected as the insulation cover masks the corrosion problem. One of the options to prevent CUI is by utilizing the protective coating systems. Thermal spray coating (TSC) is an advanced coating system and it shows promising performance in harsh environment, which could be used to prevent CUI. However, the application of TSC is not attractive due to the high initial cost. This work evaluates the potential of TSC based on corrosion performance using linear polarization resistance (LPR) method and salt spray test (SST). Prior to the evaluation, the mechanical performance of TSC was first investigated using adhesion test and bend test. Microstructure characterization of the coating was investigated using Scanning Electron Microscope (SEM). The LPR test results showed that low corrosion rate of 0.05 mm/years was obtained for TSC in compared to the bare steel especially at high temperature of 80 °C, where usually normal coating would fail. For the salt spray test, there was no sign of corrosion products especially at the center (fully coated region) was observed. From SEM images, no corrosion defects were observed after 336 hours of continuous exposure to salt fog test. This indicates that TSC protected the steel satisfactorily by acting as a barrier from a corrosive environment. In conclusion, TSC can be a possible solution to minimize the CUI in a long term. Further research should be done on corrosion performance and life cycle cost by comparing TSC with other conventional coating technology.

  5. Evaluation of the thermal insulation of clothing of infants sleeping outdoors in Northern winter.

    Science.gov (United States)

    Tourula, Marjo; Fukazawa, Takako; Isola, Arja; Hassi, Juhani; Tochihara, Yutaka; Rintamäki, Hannu

    2011-04-01

    It is a common practice in Northern countries that children aged about 2 weeks to 2 years take their daytime sleep outdoors in prams in winter. The aim was to evaluate the thermal insulation of clothing of infants sleeping outdoors in winter. Clothing data of infants aged 3.5 months was collected, and sleep duration, skin and microclimate temperatures, humidity inside middle wear, air temperature and velocity of the outdoor environment were recorded during sleep taken outdoors (n = 34) and indoors (n = 33) in families' homes. The insulation of clothing ensembles was measured by using a baby-size thermal manikin, and the values were used for defining clothing insulation of the observed infants. Required clothing insulation for each condition was estimated according to ISO 11079. Clothing insulation did not correlate with ambient air temperature. The observed and required insulation of the study group was equal at about -5 °C, but overdressing existed in warmer and deficiency in thermal insulation in colder temperatures (r (s) 0.739, p insulation increased, the cooling rate of T (sk) increased linearly (r (s) 0.605, p thermal insulation for outdoor sleeping infants during northern winter. Therefore, the necessity for guidelines is obvious. The study provides information for adequate cold protection of infants sleeping in cold conditions.

  6. Comparison of Dissolved Gases in Mineral and Vegetable Insulating Oils under Typical Electrical and Thermal Faults

    Directory of Open Access Journals (Sweden)

    Chenmeng Xiang

    2016-04-01

    Full Text Available Dissolved gas analysis (DGA is attracting greater and greater interest from researchers as a fault diagnostic tool for power transformers filled with vegetable insulating oils. This paper presents experimental results of dissolved gases in insulating oils under typical electrical and thermal faults in transformers. The tests covered three types of insulating oils, including two types of vegetable oil, which are camellia insulating oil, Envirotemp FR3, and a type of mineral insulating oil, to simulate thermal faults in oils from 90 °C to 800 °C and electrical faults including breakdown and partial discharges in oils. The experimental results reveal that the content and proportion of dissolved gases in different types of insulating oils under the same fault condition are different, especially under thermal faults due to the obvious differences of their chemical compositions. Four different classic diagnosis methods were applied: ratio method, graphic method, and Duval’s triangle and Duval’s pentagon method. These confirmed that the diagnosis methods developed for mineral oil were not fully appropriate for diagnosis of electrical and thermal faults in vegetable insulating oils and needs some modification. Therefore, some modification aiming at different types of vegetable oils based on Duval Triangle 3 were proposed in this paper and obtained a good diagnostic result. Furthermore, gas formation mechanisms of different types of vegetable insulating oils under thermal stress are interpreted by means of unimolecular pyrolysis simulation and reaction enthalpies calculation.

  7. Clothing resultant thermal insulation determined on a movable thermal manikin. Part II: effects of wind and body movement on local insulation.

    Science.gov (United States)

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Zhang, Chengjiao; Shi, Wen

    2015-10-01

    Part II of this two-part series study was focused on examining the effects of wind and body movement on local clothing thermal insulation. Seventeen clothing ensembles with different layers (i.e., 1, 2, or 3 layers) were selected for this study. Local thermal insulation with different air velocities (0.15, 1.55, and 4.0 m/s) and walking speeds (0, 0.75, and 1.17 m/s) were investigated on a thermal manikin. Empirical equations for estimating local resultant clothing insulation as a function of local insulation, air velocity, and walking speed were developed. The results showed that the effects of wind and body movement on local resultant thermal resistance are complex and differ distinctively among different body parts. In general, the reductions of local insulation with wind at the chest, abdomen, and pelvis were greater than those at the lower leg and back, and the changes at the body extremity such as the forearm, thigh, and lower leg were higher than such immobile body parts as the chest and back. In addition, the wind effect interacted with the walking effect. This study may have important applications in human local thermal comfort modeling and functional clothing design.

  8. Thermal Performance of a Customized Multilayer Insulation (MLI). Design and Fabrication of Test Facility Hardware

    Science.gov (United States)

    Leonhard, K. E.

    1975-01-01

    The design, fabrication, and assembly of hardware for testing the performance of a customized multilayer insulation are discussed. System components described include the thermal payload simulator, the modified cryoshroud, and a tank back pressure control device designed to maintain a constant liquid boiling point during the thermal evaluation of the multilayer insulation. The thermal payload simulator will provide a constant temperature surface in the range of 20.5 to 417K (37 to 750R) for the insulated tank to view. The cryoshroud was modified to establish a low temperature black body cavity while limiting liquid hydrogen usage to a minimum feasible rate.

  9. Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation.

    Science.gov (United States)

    Fan, Bitao; Chen, Shujun; Yao, Qiufang; Sun, Qingfeng; Jin, Chunde

    2017-03-17

    Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation properties through the flammability test, which indicated that the as-prepared composite aerogels would have a promising future in the application of some important areas such as protection of lightweight construction materials.

  10. Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation

    Science.gov (United States)

    Fan, Bitao; Chen, Shujun; Yao, Qiufang; Sun, Qingfeng; Jin, Chunde

    2017-01-01

    Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation properties through the flammability test, which indicated that the as-prepared composite aerogels would have a promising future in the application of some important areas such as protection of lightweight construction materials. PMID:28772670

  11. Lighter touch keeps in the heat. [Advantages of low-thermal-mass insulation

    Energy Technology Data Exchange (ETDEWEB)

    Pipes, A.

    1979-04-01

    Low-thermal-mass insulation of ceramic fibers and light refractory materials is more suitable to applications with intermittent processes and lower-temperature melting and retreating, where the heat-retention requirements do not require traditional furnace design. Old furnaces can be retrofitted by replacing bricks with insulation or by veneering. Insulating materials include ceramic, alumina, and quartz fibers, and microtherm in the form of blocks, blankets and other shapes. 4 figures. (DCK)

  12. Comparison of thermal insulation performance of fibrous materials for the advanced space suit.

    Science.gov (United States)

    Paul, Heather L; Diller, Kenneth R

    2003-10-01

    The current multi-layer insulation used in the extravehicular mobility unit (EMU) will not be effective in the atmosphere of Mars due to the presence of interstitial gases. Alternative thermal insulation means have been subjected to preliminary evaluation by NASA to attempt to identify a material that will meet the target conductivity of 0.005 W/m-K. This study analyzes numerically the thermal conductivity performance for three of these candidate insulating fiber materials in terms of various denier (size), interstitial void fractions, interstitial void media, and orientations to the applied temperature gradient to evaluate their applicability for the new Mars suit insulation. The results demonstrate that the best conductive insulation is achieved for a high-void-fraction configuration with a grooved fiber cross section, aerogel void medium, and the fibers oriented normal to the heat flux vector. However, this configuration still exceeds the target thermal conductivity by a factor of 1.5.

  13. Bionics in textiles: flexible and translucent thermal insulations for solar thermal applications.

    Science.gov (United States)

    Stegmaier, Thomas; Linke, Michael; Planck, Heinrich

    2009-05-13

    Solar thermal collectors used at present consist of rigid and heavy materials, which are the reasons for their immobility. Based on the solar function of polar bear fur and skin, new collector systems are in development, which are flexible and mobile. The developed transparent heat insulation material consists of a spacer textile based on translucent polymer fibres coated with transparent silicone rubber. For incident light of the visible spectrum the system is translucent, but impermeable for ultraviolet radiation. Owing to its structure it shows a reduced heat loss by convection. Heat loss by the emission of long-wave radiation can be prevented by a suitable low-emission coating. Suitable treatment of the silicone surface protects it against soiling. In combination with further insulation materials and flow systems, complete flexible solar collector systems are in development.

  14. High-Temperature Properties of Ceramic Fibers and Insulations for Thermal Protection of Atmospheric Entry and Hypersonic Cruise Vehicles

    Science.gov (United States)

    Kourtides, Demetrius A.; Pitts, William C.; Araujo, Myrian; Zimmerman, R. S.

    1988-01-01

    Multilayer insulations which will operate in the 500C to 1000C temperature range are being considered for possible applications on aerospace vehicles subject to convective and radiative heating during atmospheric entry. The insulations described in this paper consist of ceramic fabrics, insulations, and metal foils quilted together using ceramic thread. As these types of insulations have highly anisotropic properties, the total heat transfer characteristics of these insulations must be determined. Data are presented on the thermal diffusivity and thermal conductivity of four types of multilayer insulations and are compared to the baseline Advanced Flexible Reusable Surface Insulation

  15. MODERN TECHNOLOGIES FOR APPLYING THE THERMAL INSULATIONS BASED ON CELLULOSE FLAKES

    Directory of Open Access Journals (Sweden)

    Daniela FIAT

    2013-05-01

    Full Text Available The paper presents cellulose thermal insulations based on cellulose flakes applied "in situ", by blowoutunder pressure. This mechanized method is using pneumatic systems with complex adjustments in order toobtain different densities and flow rates, when spraying the cellulose fibbers into the spaces to be insulated.

  16.  Thermal Insulation System Made of Wood and Paper for Use in Residential Construction

    Science.gov (United States)

    Zoltán Pásztory; Tibor Horváth; Samuel V. Glass; Samuel L. Zelinka

    2015-01-01

    This article introduces an insulation system that takes advantage of the low thermal conductivity of still air and is made of wood and paper. The insulation, called the Mirrorpanel, is constructed as a panel of closely spaced layers of coated paper and held together in a frame of wood or fiberboard. Panels have been fabricated and tested at the laboratory scale, whole...

  17. Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability

    NARCIS (Netherlands)

    Bröde, P.; Kuklane, K.; Candas, V.; Hartog, E.A. den; Griefahn, B.; Holmér, I.; Meinander, H.; Nocker, W.; Richards, M.; Havenith, G.

    2010-01-01

    The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were

  18. Study on the Microscopic Figures of Power Transformer Insulation Paper Under Electrical and Thermal Stresses

    Science.gov (United States)

    Liao, Rui-Jin; Tang, Chao; Yang, Li-Jun

    In this paper, Atomic Force Microscope (AFM) was used to observe the microscopic figure of aged insulation paper in order to analyze the microscopic ageing mechanism of power transformer insulation paper under electrical and thermal stresses. The results indicate that there are obvious concaves and convexes on the surface of aged insulation paper, and the paper samples are punctured because of chain scission and the flow of discharge current, which destroyed the compact cellulose chains structures and the diameter of punctures is about 0.5 nm. In addition, this paper analyzed the influence to the physical chemistry characteristics of insulation paper caused by partial discharge and paper ageing.

  19. Applicability test of new nanotechnology thermal insulation material Spacloft into building constructions

    OpenAIRE

    Zrim, Grega

    2009-01-01

    The subject of the thesis is influence analysis of aerogel thermal insulation material implementation into constructional complexes. The work is separated into three modules, each of them represents a different scale of observation. First one is dedicated to technical characteristics of the material and a short comparison with the characteristics of two other insulation materials. Second module introduces a more vast stationary thermal analysis of the constructional complexes with different c...

  20. Thermal degradation of multilayer insulation due to the presence of penetrations

    Science.gov (United States)

    Johnson, W. L.; Kelly, A. O.; Fesmire, J. E.

    2014-01-01

    Invented in the 1950s, cryogenic multilayer insulation (MLI) continues to be studied, tested, and analyzed as it represents a complex system that is integral with the total system to be insulated. Numerous tank and calorimeter tests have been performed using many different insulation approaches. Many different variables have been tested and documented, mainly within the insulation system itself. There are several factors in insulation application that can drive up the heat load on the entire system. These include the treatment of insulation seams, instrumentation wires running through the insulation, and the integration of the insulation with the structures and fluids. Several attempts have been made to identify the performance losses due to structural integration with a real system. Due to the nature of MLI, these were tied to specific programs and configuration dependent. In an effort to understand the complex heat transfer mechanisms surrounding such systems, a series of calorimeter testing coupled with thermal modeling of the calorimeter tests was put into place. Testing showed that a buffer of micro-fiberglass material such as Cryolite is a robust method of closing out MLI penetrations. Additionally, a validated thermal model was used to develop parametric analysis far beyond the limitations of the calorimeter testing. This paper presents the methodology and approach, with experimental data providing the basis for developing the thermal model and its results for applicability to future design cases.

  1. Development of New Generation of Thermally-Enhanced Fiber Glass Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, Jan [ORNL; Yarbrough, David W [ORNL; Childs, Phillip W [ORNL; Miller, William A [ORNL; Atchley, Jerald Allen [ORNL; Shrestha, Som S [ORNL

    2010-03-01

    This report presents experimental and numerical results from thermal performance studies. The purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC and John s Manville was to design a basic concept of a new generation of thermally-enhanced fiber glass insulation. Different types of Phase Change Materials (PCMs) have been tested as dynamic components in buildings during the last 4 decades. Most historical studies have found that PCMs enhance building energy performance. Some PCM-enhanced building materials, like PCM-gypsum boards or PCM-impregnated concretes have already found their limited applications in different countries. Today, continued improvements in building envelope technologies suggest that throughout Southern and Central U.S. climates, residences may soon be routinely constructed with PCM in order to maximize insulation effectiveness and maintain low heating and cooling loads. The proposed thermally-enhanced fiber glass insulation will maximize this integration by utilizing a highly-efficient building envelope with high-R thermal insulation, active thermal mass and superior air-tightness. Improved thermal resistance will come from modifications in infrared internal characteristics of the fiber glass insulation. Thermal mass effect can be provided by proprietary thermally-active microencapsulated phase change material (PCM). Work carried out at the Oak Ridge National Laboratory (ORNL) on the CRADA is described in this report.

  2. Radiative contribution to thermal conductance in animal furs and other woolly insulators.

    Science.gov (United States)

    Simonis, Priscilla; Rattal, Mourad; Oualim, El Mostafa; Mouhse, Azeddine; Vigneron, Jean-Pol

    2014-01-27

    This paper deals with radiation's contribution to thermal insulation. The mechanism by which a stack of absorbers limits radiative heat transfer is examined in detail both for black-body shields and grey-body shields. It shows that radiation energy transfer rates should be much faster than conduction rates. It demonstrates that, for opaque screens, increased reflectivity will dramatically reduce the rate of heat transfer, improving thermal insulation. This simple model is thought to contribute to the understanding of how animal furs, human clothes, rockwool insulators, thermo-protective containers, and many other passive energy-saving devices operate.

  3. Tests of thermal resistance of simulated walls with the reflective insulation

    Directory of Open Access Journals (Sweden)

    Piotrowski Jerzy Zb.

    2014-03-01

    Full Text Available The paper presents the thermal resistance characteristics of walls with multilayer reflective insulation. The tests have been performed using a heat flow meter to determine the resistivity of the layers simulating partition walls in buildings. A modification of the structure has also been proposed and analysed with a view to increase the thermal resistance and, consequently, reduce the heat flux transferred through the walls. Consequently, walls produced with layers that ensure higher thermal insulation lead to better thermal performance properties of the whole buildings, which reduce heating/cooling costs throughout the year.

  4. Thermal highly porous insulation materials made of mineral raw materials

    Science.gov (United States)

    Mestnikov, A.

    2015-01-01

    The main objective of the study is to create insulating foam based on modified mineral binders with rapid hardening. The results of experimental studies of the composition and properties of insulating foam on the basis of rapidly hardening Portland cement (PC) and gypsum binder composite are presented in the article. The article proposes technological methods of production of insulating foamed concrete and its placement to the permanent shuttering wall enclosures in monolithic-frame construction and individual energy-efficient residential buildings, thus reducing foam shrinkage and improving crack-resistance.

  5. Partial Insulation of Aerated Concrete Wall in its Thermal Bridge Regions

    Science.gov (United States)

    Li, Baochang; Guo, Lirong; Li, Yubao; Zhang, Tiantian; Tan, Yufei

    2018-01-01

    As a self-insulating building material which can meet the 65 percent energy-efficiency requirements in cold region of China, aerated concrete blocks often go moldy, frost heaving, or cause plaster layer hollowing at thermal bridge parts in the extremely cold regions due to the restrictions of environmental climate and construction technique. In this paper, partial insulation measures of the thermal-bridge position of these parts of aerated concrete walls are designed to weaken or even eliminate thermal bridge effect and improve the temperature of thermal-bridge position. A heat transfer calculation model for L-shaped wall and T-shaped wall is developed. Based on the simulation result, the influence of the thickness on the temperature field is analyzed. Consequently, the condensation inside self-thermal-insulating wall and frost heaving caused by condensation and low temperature will be reduced, avoiding damage to the wall body from condensation..

  6. The use of footwear insulation values measured on a thermal foot model.

    Science.gov (United States)

    Kuklane, Kalev

    2004-01-01

    The use of physiological data from human tests in modelling should consider background data, such as activity, environmental factors and clothing insulation on the whole body. The present paper focuses on local thermal comfort of feet with special attention on the effects of physical changes of footwear thermal properties. An alternative test method is available for footwear thermal testing besides the standard method. The possibility to use insulation values acquired on a thermal foot model in practice is shown here. The paper describes the correlation between cold and pain sensations, and foot skin temperatures of the subjects and relates these to insulation measured on a thermal foot model. Recommendations are made for footwear choice according to environmental temperature.

  7. Thermal comfort and clothing insulation of resting tent occupants at high altitude.

    Science.gov (United States)

    Cena, Krzysztof; Davey, Nicole; Erlandson, Tamara

    2003-11-01

    Thirty-nine males and 18 females, in six groups, participated in six high altitude treks (each lasting 3-4 weeks and climbing up to 5500m) in the Himalaya and Karakoram. Inverse relationships between mean overnight total insulation (sleeping bag plus clothing) and air temperature in tents were recorded for all treks. Average overnight thermal sensations varied little with air temperature as the subjects modified their clothing insulation to maintain thermal sensations warmer than 'neutral' for all treks. For combined treks, subjects adjusted their mean overnight total insulation up to 7clo for thermal sensations of between 0 ('neutral') and +1 ('slightly warm') on average, measured on the standard seven-point thermal sensation scale developed for everyday low-altitude conditions. Very few subjects (3% of all daily responses, on average) reported 'cool' or 'cold' sensations. General tent discomfort increased with altitude suggesting that subjects interpreted tent comfort predominantly in terms of thermal outdoor conditions.

  8. Comparison of floating and thermalized multilayer insulation systems at low boundary temperature

    CERN Document Server

    Ferlin, G; Lebrun, P; Peón-Hernández, G; Riddone, G; Szeless, Balázs

    1997-01-01

    The Large Hadron Collider (LHC) is 26.7 km circumference particle collider using high-field superconducting magnets operating in superfluid helium. An efficient and robust thermal insulation system is therefore required to minimize the residual heat in leak to the large surface area at 1.9 K constituted by the stainless steel wall of the helium enclosure. The baseline solution uses "floating" multilayer reflective insulation. Moreover, an alternative consists of a combination of multilayer reflective films and a soft screen, partially thermalized to the 5 K level and supported away from the cold wall by net-type insulating spacers. This chapter establishes the improvement potential of the alternative over the baseline solution, and compares their insulation performance on the basis of measured characteristics of thermal contacts and spacers.

  9. A Facile Approach to Evaluate Thermal Insulation Performance of Paper Cups

    Directory of Open Access Journals (Sweden)

    Yudi Kuang

    2015-01-01

    Full Text Available Paper cups are ubiquitous in daily life for serving water, soup, coffee, tea, and milk due to their convenience, biodegradability, recyclability, and sustainability. The thermal insulation performance of paper cups is of significance because they are used to supply hot food or drinks. Using an effective thermal conductivity to accurately evaluate the thermal insulation performance of paper cups is complex due to the inclusion of complicated components and a multilayer structure. Moreover, an effective thermal conductivity is unsuitable for evaluating thermal insulation performance of paper cups in the case of fluctuating temperature. In this work, we propose a facile approach to precisely analyze the thermal insulation performance of paper cups in a particular range of temperature by using an evaluation model based on the MISO (Multiple-Input Single-Output technical theory, which includes a characterization parameter (temperature factor and a measurement apparatus. A series of experiments was conducted according to this evaluation model, and the results show that this evaluation model enables accurate characterization of the thermal insulation performance of paper cups and provides an efficient theoretical basis for selecting paper materials for paper cups.

  10. The influence of thermal insulation position in building exterior walls on indoor thermal comfort and energy consumption of residential buildings in Chongqing

    Science.gov (United States)

    Wang, D.; Yu, W.; Zhao, X.; Dai, W.; Ruan, Y.

    2016-08-01

    This paper focused on the influence of using position of thermal insulation materials in exterior walls on the indoor thermal comfort and building energy consumption of residential building in Chongqing. In this study, four (4) typical residential building models in Chongqing were established, which have different usage of thermal insulation layer position in exterior walls. Indoor thermal comfort hours, cooling and heating energy consumption of each model were obtained by using a simulation tool, Energyplus. Based on the simulation data, the influence of thermal insulation position on indoor thermal comfort and building energy consumption in each season was analyzed. The results showed that building with internal insulation had the highest indoor thermal comfort hours and least cooling and heating energy consumption in summer and winter. In transitional season, the highest indoor thermal comfort hours are obtained when thermal insulation is located on the exterior side.

  11. Thermal Insulating Properties of Straw-Filled Environmentally Friendly Building Materials

    Directory of Open Access Journals (Sweden)

    Petkova-Slipets Rositsa

    2017-06-01

    Full Text Available The paper presents results of a research for determination of a few general thermal-physical properties of environmentally friendly building materials made by clay, sand and straw. The aim of this study is to establish their heat insulating and energy-efficient capacity. All specific measurements were carried out by using the newest generation thermal conductivity analyser Mathis TCi.

  12. An apparatus to measure the thermal conductivity of insulation panels at sub-ambient temperature

    NARCIS (Netherlands)

    Vanapalli, Srinivas; Klünder, T.; Hegeman, I.; Tolboom, A.H.; ter Brake, Hermanus J.M.

    2017-01-01

    A single-sided guarded-plate apparatus has been developed to measure the thermal conductivity of insulation panels of sub-meter size at sub-ambient temperatures ranging from 250 to 300 K. This apparatus allows thermal conductivity measurements to be performed at large temperature differences

  13. Transient thermal sensation and comfort resulting from adjustment of clothing insulation

    DEFF Research Database (Denmark)

    Goto, Tomonobu; Toftum, Jørn; Fanger, Povl Ole

    2003-01-01

    This study investigated the transient effects on human thermal responses of clothing adjustments. Two different levels of activity were tested, and the temperature was set to result in a warm or cool thermal sensation at each activity level. The subjects (12 females and 12 males) wore identical...... minutes after both an increase and a decrease of clothing insulation, independent of the activity level....

  14. Molecular sieves control contamination and and insulate in thermal regenerators - A concept

    Science.gov (United States)

    Gasser, M. G.

    1970-01-01

    Zeolitic molecular sieves prolong the lives of cryogenic engines by preventing contamination of the thermal regenerators on the cold ends of closed-cycle engines. Sieves also serve as thermal insulators by preventing conduction of heat along regenerators through contiguous disks of mesh.

  15. Prediction of clothing thermal insulation and moisture vapour resistance of the clothed body walking in wind.

    Science.gov (United States)

    Qian, Xiaoming; Fan, Jintu

    2006-11-01

    Clothing thermal insulation and moisture vapour resistance are the two most important parameters in thermal environmental engineering, functional clothing design and end use of clothing ensembles. In this study, clothing thermal insulation and moisture vapour resistance of various types of clothing ensembles were measured using the walking-able sweating manikin, Walter, under various environmental conditions and walking speeds. Based on an extensive experimental investigation and an improved understanding of the effects of body activities and environmental conditions, a simple but effective direct regression model has been established, for predicting the clothing thermal insulation and moisture vapour resistance under wind and walking motion, from those when the manikin was standing in still air. The model has been validated by using experimental data reported in the previous literature. It has shown that the new models have advantages and provide very accurate prediction.

  16. Influence on Occupant Responses of Behavioral Modification of Clothing Insulation in Nonsteady Thermal Environments (RP-1269)

    DEFF Research Database (Denmark)

    Toftum, Jørn; Kolarik, Jakub; Belkowska, D.

    2010-01-01

    This paper presents climate chamber experiment results in which subjects were exposed to increasing and decreasing dynamic temperature drifts while being allowed to adjust their clothing insulation as desired. The objective of the study was to substantiate the scientific basis of the recommendati......This paper presents climate chamber experiment results in which subjects were exposed to increasing and decreasing dynamic temperature drifts while being allowed to adjust their clothing insulation as desired. The objective of the study was to substantiate the scientific basis....../h) condition when it was 2 h. Thermal sensation responses observed with adjustable clothing insulation did not differ from those observed with fixed clothing insulation, which were reported in an earlier paper. However, with fired clothing insulation, longer exposures (>4 h) seemed to aggravate general sick...

  17. Thermal Testing and Analysis of an Efficient High-Temperature Multi-Screen Internal Insulation

    Science.gov (United States)

    Weiland, Stefan; Handrick, Karin; Daryabeigi, Kamran

    2007-01-01

    Conventional multi-layer insulations exhibit excellent insulation performance but they are limited to the temperature range to which their components reflective foils and spacer materials are compatible. For high temperature applications, the internal multi-screen insulation IMI has been developed that utilizes unique ceramic material technology to produce reflective screens with high temperature stability. For analytical insulation sizing a parametric material model is developed that includes the main contributors for heat flow which are radiation and conduction. The adaptation of model-parameters based on effective steady-state thermal conductivity measurements performed at NASA Langley Research Center (LaRC) allows for extrapolation to arbitrary stack configurations and temperature ranges beyond the ones that were covered in the conductivity measurements. Experimental validation of the parametric material model was performed during the thermal qualification test of the X-38 Chin-panel, where test results and predictions showed a good agreement.

  18. Foam/Aerogel Composite Materials for Thermal and Acoustic Insulation and Cryogen Storage

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Weiser, Erik S. (Inventor); Sass, Jared P. (Inventor)

    2011-01-01

    The invention involves composite materials containing a polymer foam and an aerogel. The composite materials have improved thermal insulation ability, good acoustic insulation, and excellent physical mechanical properties. The composite materials can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power. The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N.sub.2 or H.sub.2, adsorbs to the surfaces in aerogel particles. Thus, another embodiment of the invention provides a storage vessel for a cryogen.

  19. Thermal insulation and clothing area factors of typical Arabian Gulf clothing ensembles for males and females: measurements using thermal manikins.

    Science.gov (United States)

    Al-ajmi, F F; Loveday, D L; Bedwell, K H; Havenith, G

    2008-05-01

    The thermal insulation of clothing is one of the most important parameters used in the thermal comfort model adopted by the International Standards Organisation (ISO) [BS EN ISO 7730, 2005. Ergonomics of the thermal environment. Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria. International Standardisation Organisation, Geneva.] and by ASHRAE [ASHRAE Handbook, 2005. Fundamentals. Chapter 8. American Society of Heating Refrigeration and Air-conditioning Engineers, Inc., 1791 Tullie Circle N.E., Atlanta, GA.]. To date, thermal insulation values of mainly Western clothing have been published with only minimal data being available for non-Western clothing. Thus, the objective of the present study is to measure and present the thermal insulation (clo) values of a number of Arabian Gulf garments as worn by males and females. The clothing ensembles and garments of Arabian Gulf males and females presented in this study are representative of those typically worn in the region during both summer and winter seasons. Measurements of total thermal insulation values (clo) were obtained using a male and a female shape thermal manikin in accordance with the definition of insulation as given in ISO 9920. In addition, the clothing area factors (f cl) determined in two different ways were compared. The first method used a photographic technique and the second a regression equation as proposed in ISO 9920, based on the insulation values of Arabian Gulf male and female garments and ensembles as they were determined in this study. In addition, fibre content, descriptions and weights of Arabian Gulf clothing have been recorded and tabulated in this study. The findings of this study are presented as additions to the existing knowledge base of clothing insulation, and provide for the first time data for Arabian Gulf clothing. The analysis showed that for these non-Western clothing designs, the

  20. Calculating thermal insulation thickness and embedment depth of underground heat supply pipeline for permafrost soils

    OpenAIRE

    M.P. Akimov; S.D. Mordovskoy; N.P. Starostin

    2014-01-01

    In this work the authors considered a freezing-and-melting process of soils under the polyurethane-insulated polyethylene heating pipeline, which is used in the regions with permafrost soils. Temperature field dynamics of the “pipeline – soil” system is determined by heat conductivity equation in polar coordinate system. The corresponding two-dimensional Stefan problem is solved by the finite differences method. The authors propose to determine the thickness of pipeline thermal insulation...

  1. Incorporation of Polymers into Calcined Clays as Improved Thermal Insulating Materials for Construction

    Directory of Open Access Journals (Sweden)

    Serina Ng

    2017-01-01

    Full Text Available Calcined clay is a Type Q supplementary cementing material according to EN197-1:2000. It possesses lower thermal conductivity than cement. To further improve its thermal insulation property, polymer-calcined clay complexes (PCCs were produced in a one-pot synthesis. Two contrasting polymers, polystyrene (PS and polyethylene glycol (PEG, were employed. The hydrophilicity of the polymers influenced the thermal conductivity of PCC. Hydrophilic PEG entrapped more water molecules on clay layers than the hydrophobic PS, making PEG-PCC more thermally conducting than PS-PCC. Contaminants in calcined clays played a role in affecting the overall thermal conductivity. PCC can improve thermal insulation properties for future construction applications.

  2. Effect of hydrophobic nano-silica on the thermal insulation of fibrous silica compacts

    Directory of Open Access Journals (Sweden)

    Tseng-Wen Lian

    2017-06-01

    Full Text Available The particle’s surface property plays an important role on controlling the thermal insulation performance of fibrous silica compacts. In the present study, the effect of addition of hydrophobic silica on the thermal conductivity of the fibrous silica compacts is investigated. The measurement was conducted using laser flash method and differential scanning calorimeter (DSC method. The thermal conductivity of fibrous silica compacts is only 0.042 W/m K. The addition of 5% hydrophobic silica further reduces the thermal conductivity of fibrous silica compacts to 0.033 W/m K. The thermal conductivity reaches a constant value with higher hydrophobic silica content. The flexural strength decreases with the increase of hydrophobic silica content. A compromise between the thermal insulation and strength is needed. The performance of fibrous silica compacts shows strong dependence on the surface structure of glass fibers.

  3. Transient analysis and improvement of indoor thermal comfort for an air-conditioned room with thermal insulations

    Directory of Open Access Journals (Sweden)

    D. Prakash

    2015-09-01

    Full Text Available Thermal insulations over the building envelop reduce the heat gain due to solar radiation and may enhance good and uniform indoor thermal comfort for the occupants. In this paper, the insulation layer-wood wool is laid over the roof and exposed wall of an air-conditioned room and its performance on indoor thermal comfort is studied by computational fluid dynamics (CFD technique. From this study, 3% of indoor thermal comfort index-predicted mean vote (PMV is improved by providing wood wool layer. In addition, the optimum supply air temperature of air-conditioning unit for good thermal comfort is predicted as in the range of 299–300 K (26–27 °C.

  4. Effect of thermal-treatment sequence on sound absorbing and mechanical properties of porous sound-absorbing/thermal-insulating composites

    Directory of Open Access Journals (Sweden)

    Huang Chen-Hung

    2016-01-01

    Full Text Available Due to recent rapid commercial and industrial development, mechanical equipment is supplemented massively in the factory and thus mechanical operation causes noise which distresses living at home. In livelihood, neighborhood, transportation equipment, jobsite construction noises impact on quality of life not only factory noise. This study aims to preparation technique and property evaluation of porous sound-absorbing/thermal-insulating composites. Hollow three-dimensional crimp PET fibers blended with low-melting PET fibers were fabricated into hollow PET/low-melting PET nonwoven after opening, blending, carding, lapping and needle-bonding process. Then, hollow PET/low-melting PET nonwovens were laminated into sound-absorbing/thermal-insulating composites by changing sequence of needle-bonding and thermal-treatment. The optimal thermal-treated sequence was found by tensile strength, tearing strength, sound-absorbing coefficient and thermal conductivity coefficient tests of porous composites.

  5. Measuring Thermal Conductivity and Moisture Absorption of Cryo-Insulation Materials

    Science.gov (United States)

    Lambert, Michael A.

    1998-01-01

    NASA is seeking to develop thermal insulation material systems suitable for withstanding both extremely high temperatures encountered during atmospheric re-entry heating and aero- braking maneuvers, as well as extremely low temperatures existing in liquid fuel storage tanks. Currently, materials used for the high temperature insulation or Thermal Protection System (TPS) are different from the low temperature, or cryogenic insulation. Dual purpose materials are necessary to the development of reusable launch vehicles (RLV). The present Space Shuttle (or Space Transportation System, STS) employs TPS materials on the orbiter and cryo-insulation materials on the large fuel tank slung under the orbiter. The expensive fuel tank is jettisoned just before orbit is achieved and it burns up while re-entering over the Indian Ocean. A truly completely reusable launch vehicle must store aR cryogenic fuel internally. The fuel tanks will be located close to the outer surface. In fact the outer skin of the craft will probably also serve as the fuel tank enclosure, as in jet airliners. During a normal launch the combined TPS/cryo-insulation system will serve only as a low temperature insulator, since aerodynamic heating is relatively minimal during ascent to orbit. During re-entry, the combined TPS/cryo-insulation system will serve only as a high temperature insulator, since all the cryogenic fuel will have been expended in orbit. However, in the event of an.aborted launch or a forced/emergency early re-entry, the tanks will still contain fuel, and the TPS/cryo-insulation will have to serve as both low and high temperature insulation. Also, on long duration missions, such as to Mars, very effective cryo-insulation materials are needed to reduce bod off of liquid propellants, thereby reducing necessary tankage volume, weight, and cost. The conventional approach to obtaining both low and high temperature insulation, such as is employed for the X-33 and X-34 spacecraft, is to use

  6. The Modeling and Simulation of Thermal Analysis at Hydro Generator Stator Winding Insulation

    Directory of Open Access Journals (Sweden)

    Mihaela Raduca

    2006-10-01

    Full Text Available This paper presents the modelling and simulation of thermal analysis at hydro generator stator winding. The winding stator is supplied at high voltage of 11 kV for high power hydro generator. To present the thermal analysis for stator winding is presented at supply of coil by 11 kV, when coil is heat and thermal transfer in insulation at ambient temperature.

  7. Thermal paint production: the techno-economic evaluation of muscovite as insulating additive.

    Directory of Open Access Journals (Sweden)

    Gabriela Fernandes Ribas

    2016-09-01

    Full Text Available Muscovite is known by its thermal and electrical insulating properties. Based on this, it was hypothesized that its addition on paints should increase the thermal resistance. The use of muscovite as mineral insulating is pointed out as advantageous due to its low cost compared to other materials used for this purpose, such as the ceramic microsphere. The use of a low cost material could open the access to the medium and low income families, implying two aspects: the life quality increase by thermal comfort and the increase of energy saving. Thus, this part of the population could open a new market to thermal paints. Aiming to contribute to this issue, this work evaluated the thermal insulation performance of commercial paints containing muscovite additions and determined the economic evaluation for its industrial production. The thermal paint was formulated by adding 10%, 20% and 40% of muscovite to the commercial paint. This was applied on steel reinforced mortar boards. Thermal insulation tests were carried out in bench scale using an adapted box. The economic evaluation of the industrial production of muscovite-based thermal paint was conducted, considering the Brazilian economic market in this activity. The results showed its ability as an insulating agent due to a reduction of 0.667 °C/mm board by the addition of 40% muscovite. The economic analysis also demonstrated the feasibility of the thermal paint industrial production. The payback is favorable to 5 years when compared to the Selic short-term lending rate, with 21.53% of internal rate return and a net present value of US$ 15,085.76.

  8. Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Bitao Fan

    2017-03-01

    Full Text Available Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation properties through the flammability test, which indicated that the as-prepared composite aerogels would have a promising future in the application of some important areas such as protection of lightweight construction materials.

  9. A quasi-physical model for predicting the thermal insulation and moisture vapour resistance of clothing.

    Science.gov (United States)

    Qian, Xiaoming; Fan, Jintu

    2009-07-01

    Based on the improved understanding of the effects of wind and walking motion on the thermal insulation and moisture vapour resistance of clothing induced by air ventilation in the clothing system, a new model has been derived based on fundamental mechanisms of heat and mass transfer, which include conduction, diffusion, radiation and natural convection, wind penetration and air ventilation. The model predicts thermal insulation of clothing under body movement and windy conditions from the thermal insulation of clothing measured when the person is standing in the still air. The effects of clothing characteristics such as fabric air permeability, garment style, garment fitting and construction have been considered in the model through the key prediction parameters. With the new model, an improved prediction accuracy is achieved with a percentage of fit being as high as 0.96.

  10. Thermal insulation for high temperature microwave sintering operations and method thereof

    Science.gov (United States)

    Holcombe, Cressie E.; Dykes, Norman L.; Morrow, Marvin S.

    1995-01-01

    Superior microwave transparent thermal insulations for high temperature microwave sintering operations were prepared. One embodiment of the thermal insulation comprises granules of boron nitride coated with a very thin layer of glassy carbon made by preparing a glassy carbon precursor and blending it with boron nitride powder to form a mixture. The blended mixture is granulated to form a grit which is dried and heated to form the granules of boron nitride coated with a glassy carbon. Alternatively, grains of glassy carbon are coated with boron nitride by blending a mixture of a slurry comprising boron nitride, boric acid binder, and methyl alcohol with glassy carbon grains to form a blended mixture. The blended mixture is dried to form grains of glassy carbon coated with boron nitride. In addition, a physical mixture of boron nitride powder and glassy carbon grains has also been shown to be an excellent thermal insulation material for microwave processing and sintering.

  11. Method of preparing thermal insulation for high temperature microwave sintering operations

    Science.gov (United States)

    Holcombe, Cressie E.; Dykes, Norman L.; Morrow, Marvin S.

    1996-01-01

    Superior microwave transparent thermal insulations for high temperature microwave sintering operations were prepared. One embodiment of the thermal insulation comprises granules of boron nitride coated with a very thin layer of glassy carbon made by preparing a glassy carbon precursor and blending it with boron nitride powder to form a mixture. The blended mixture is granulated to form a grit which is dried and heated to form the granules of boron nitride coated with a glassy carbon. Alternatively, grains of glassy carbon are coated with boron nitride by blending a mixture of a slurry comprising boron nitride, boric acid binder, and methyl alcohol with glassy carbon grains to form a blended mixture. The blended mixture is dried to form grains of glassy carbon coated with boron nitride. In addition, a physical mixture of boron nitride powder and glassy carbon grains has also been shown to be an excellent thermal insulation material for microwave processing and sintering.

  12. Thermal insulating barrier and neutron shield providing integrated protection for a nuclear reactor vessel

    Science.gov (United States)

    Schreiber, Roger B.; Fero, Arnold H.; Sejvar, James

    1997-01-01

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel to form a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive valving also includes bistable vents at the upper end of the thermal insulating barrier for releasing steam. A removable, modular neutron shield extending around the upper end of the reactor cavity below the nozzles forms with the upwardly and outwardly tapered transition on the outer surface of the reactor vessel, a labyrinthine channel which reduces neutron streaming while providing a passage for the escape of steam during a severe accident, and for the cooling air which is circulated along the reactor cavity walls outside the thermal insulating barrier during normal operation of the reactor.

  13. Effect of hygric and thermal properties of connecting layers on the performance of interior thermal insulation systems

    Science.gov (United States)

    Kočí, Václav; Jerman, Miloš; Fiala, Lukáš; Černý, Robert

    2017-11-01

    Interior thermal insulation systems represent often the only way of thermal protection, especially when historical buildings are taken into account. Since these systems face distrust due to frequent moisture failures, alternative solutions substituting the common water vapor barrier are being sought. In this paper, an assessment of hygrothermal performance of interior thermal insulation systems with purposely developed connecting layers is presented. Two types of mineral wools are connected to a sandstone masonry using two different connecting materials. The hygrothermal performance of the wall is obtained as a result of computational modelling with experimentally determined material parameters. Dynamic boundary conditions in the form of climatic data for Prague are used. The results indicate that the combination of permeable thermal insulation materials with investigated connecting layers have a positive influence on hygrothermal performance of the system as the moisture content is kept on very low level during a reference year. On the other hand, an increased attention should be paid to the protection of the masonry against excessive weather straining due to the absence of exterior thermal insulation.

  14. Vacuum Insulation Panels: Analysis of the Thermal Performance of Both Single Panel and Multilayer Boards

    Directory of Open Access Journals (Sweden)

    Alfonso Capozzoli

    2015-03-01

    Full Text Available The requirements for improvement in the energy efficiency of buildings, mandatory in many EU countries, entail a high level of thermal insulation of the building envelope. In recent years, super-insulation materials with very low thermal conductivity have been developed. These materials provide satisfactory thermal insulation, but allow the total thickness of the envelope components to be kept below a certain thickness. Nevertheless, in order to penetrate the building construction market, some barriers have to be overcome. One of the main issues is that testing procedures and useful data that are able to give a reliable picture of their performance when applied to real buildings have to be provided. Vacuum Insulation Panels (VIPs are one of the most promising high performing technologies. The overall, effective, performance of a panel under actual working conditions is influenced by thermal bridging, due to the edge of the panel envelope and to the type of joint. In this paper, a study on the critical issues related to the laboratory measurement of the equivalent thermal conductivity of VIPs and their performance degradation due to vacuum loss has been carried out utilizing guarded heat flux meter apparatus. A numerical analysis has also been developed to study thermal bridging effect when VIP panels are adopted to create multilayer boards for building applications.

  15. Retrofitting of compound systems of thermal insulation. Mantle on the jacket; Sanierung von WDVS durch Aufdoppelung. Mantel ueber der Jacke

    Energy Technology Data Exchange (ETDEWEB)

    Siegele, Klaus

    2011-03-15

    More than thirty years ago the era of compound systems of thermal insulation started - using five to eight centimetres thin polystyrene insulation panels, in the 1970ies the pioneers of the facade insulation responded to the dictation of the oil sheik and set thereby the course for the development of an energy efficient design for the first time. In the meantime the thermoskins of the first hour lost some of its shine and also correspond no more to the today's insulation standard. Their retrofitting lines up. Thus the question arises: Demolition, disposal and assembly of a new compound system of thermal insulation? Or are panels the better solution?.

  16. Multilevel radiative thermal memory realized by the hysteretic metal-insulator transition of vanadium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kota, E-mail: kotaito@mosk.tytlabs.co.jp; Nishikawa, Kazutaka; Iizuka, Hideo [Toyota Central Research and Development Labs, Nagakute, Aichi 480-1192 (Japan)

    2016-02-01

    Thermal information processing is attracting much interest as an analog of electronic computing. We experimentally demonstrated a radiative thermal memory utilizing a phase change material. The hysteretic metal-insulator transition of vanadium dioxide (VO{sub 2}) allows us to obtain a multilevel memory. We developed a Preisach model to explain the hysteretic radiative heat transfer between a VO{sub 2} film and a fused quartz substrate. The transient response of our memory predicted by the Preisach model agrees well with the measured response. Our multilevel thermal memory paves the way for thermal information processing as well as contactless thermal management.

  17. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Mohamad Irfan Fathurrohman

    2015-07-01

    Full Text Available The vulcanization kinetics of Ethylene-propylene diene monomer (EPDM rubber thermal insulation was studied by using rheometer under isothermal condition at different temperatures. The rheometry analysis was used to determining the cure kinetic parameters and predicting the cure time of EPDM thermal insulation. The experimental results revealed that the curing curves of EPDM thermal insulation were marching and the optimum curing time decreased with increasing the temperature. The kinetic parameters were determined from the autocatalytic model showed close fitting with the experimental results, indicating suitability of autocatalytic model in characterizing the cure kinetics. The activation energy was determined from the autocatalytic model is 46.3661 kJ mol-1. The cure time were predicted from autocatalytic model and the obtained kinetic parameter by using the relationship among degree of conversion, cure temperature, and cure time. The predictions of cure time provide information for the actual curing characteristic of EPDM thermal insulation. The mechanical properties of EPDM thermal insulation with different vulcanization temperatures showed the same hardness, tensile strength and modulus at 300%, except at temperature 70 °C, while the elongation at breaking point decreased with increasing temperature of vulcanization. © 2015 BCREC UNDIP. All rights reservedReceived: 8th April 2014; Revised: 7th January 2015; Accepted: 16th January 2015How to Cite: Fathurrohman, M.I., Maspanger, D.R., Sutrisno, S. (2015. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation. Bulletin of Chemi-cal Reaction Engineering & Catalysis, 10 (2, 104-110. (doi:10.9767/bcrec.10.2.6682.104-110Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.6682.104-110 

  18. Thermal insulation and SIDS-an investigation of selected 'Eastern' and 'Western' infant bedding combinations.

    Science.gov (United States)

    Wilson, C A; Chu, M S

    2005-08-01

    Differences in the incidence of SIDS between 'Western' and 'Eastern' countries has been attributed to cultural practices, which may affect the infants care and thermal environment. The purpose of this work was to estimate for selected 'commonly' used bedding, sleep positions and practices in Japan, Korea and New Zealand, the intrinsic 'dry' thermal resistance of bedding. Insulation levels are also discussed in the context of published information about the thermal environment in which the bedding is likely to be used. Selected Japanese, Korean and New Zealand bedding was loosely tucked over an infant manikin in the lateral, prone and supine sleep positions. Thickness in use was measured, and intrinsic 'dry' thermal resistance estimated using the Wilson Laing model which accommodates the effect on insulation of the three-dimensional arrangement of bedding combinations during use. Thickness of under- and upper-bedding varied among countries with thickness and estimated 'dry' thermal resistance of the upper-bedding affected by the type/combination of bedding and the infants sleep position. Insulation levels are discussed in relation to environmental conditions within and among countries and between seasons. Further information on thermal environments, bedding combinations used and care practices within both Asian and Western countries is needed. 'Eastern' infants appear likely to be generally covered in bedding combinations of greater insulation than those used to cover 'Western' infants in comparable seasons. Differences existed between insulation of the Japanese and Korean bedding combinations investigated. Lower rates of SIDS apparent in 'Asian' populations do not appear attributable to use of lower levels of bedding insulation only.

  19. Thermal blanket insulation for advanced space transportation systems

    Science.gov (United States)

    Pusch, Richard H.

    1985-01-01

    The feasibility of weaving Nextel ceramic and Nicalon silicon carbide yarns into integrally woven, three dimensional fluted core fabrics was demonstrated. Parallel face fabrics joined with woven fabric ribs to form triangular cross section flutes between the faces were woven into three single and one double layer configuration. High warp yarn density in the double layer configuration caused considerable yarn breakage during weaving. The flutes of all four fabrics were filled with mandrels made from Q-Fiber Felt and FRCI-20-12 to form candidate insulation panels for advanced Space Transportation Systems. Procedures for preparing and inserting the mandrels were developed. Recommendations are made on investigating alternate methods for filling the flutes with insulation, and for improving the weaving of these types of fabrics.

  20. Cellulose loose-fill insulation material. Thermal transmittance determined by means of heat flow meters; Papirisolering. Varmeisoleringsevne maalt med varmestroemsmaaler

    Energy Technology Data Exchange (ETDEWEB)

    Nicolajsen, Asta

    2001-07-01

    Determination of design values of thermal conductivity, {lambda}{sub p}, for insulation materials is based on the laboratory measured {lambda}-value ((lampbda){sub 10}) of dry materials and experience gained over many years. Only limited documentation regarding cellulose loose-fill insulation is available, as this type of insulation has only been used in Denmark for comparatively few years. By og Byg has received a grant to investigate the insulating properties of cellulose insulation materials in a number of facade elements, including the dependency of insulating properties on the moisture content. The insulating properties also depends on other parameters, e.g. workmanship in connection with the actual insulation and any subsequent settling of the insulation material. These aspects has not been investigated in this project. (au)

  1. Smoldering combustion hazards of thermal-insulation materials

    Energy Technology Data Exchange (ETDEWEB)

    Ohlemiller, J.

    1981-08-01

    The smoldering combustion hazards of cellulosic loose fill insulation materials fall into three categories: smolder initiation, smolder propagation, and transition from smoldering into flaming. Previous findings on the initiation problem are summarized briefly. They serve as the basis for recommendations on an improved smolder ignition test method which is designed to give ignition temperatures comparable to those in practice. The proposed test method requires checking against full-scale mock-up results before it can be considered for implementation. Smolder propagation, driven by buoyant convection, through a thick (18 cm) layer of cellulosic insulation has been extensively examined. A heavy (25% add-on) loading of boric acid (a widely used smolder retardant) cuts the propagation rate in half (from approx. 0.3 to 0.15 cm/min) but does not come close to stopping this process. Analysis of experimental profiles for temperature, oxygen level, and remaining organic fraction strongly indicates that the smolder wave is oxygen-supply controlled and that it involves both first and second stages of oxidative heat release from the insulation material. The balance of involvement of the two stages varies with depth in the layer. It appears that efforts to develop improved means of suppressing smolder propagation must be directed at the entire oxidation process. However, since boric acid is fairly effective at slowing the second stage of oxidation, most new efforts should be aimed at the first stage of oxidation (which also is responsible for smolder initiation).

  2. Anisotropic fibrous thermal insulator of relatively thick cross section and method for making same

    Science.gov (United States)

    Reynolds, Carl D.; Ardary, Zane L.

    1979-01-01

    The present invention is directed to an anisotropic thermal insulator formed of carbon-bonded organic or inorganic fibers and having a thickness or cross section greater than about 3 centimeters. Delaminations and deleterious internal stresses generated during binder curing and carbonizing operations employed in the fabrication of thick fibrous insulation of thicknesses greater than 3 centimeters are essentially obviated by the method of the present invention. A slurry of fibers, thermosetting resin binder and water is vacuum molded into the selected insulator configuration with the total thickness of the molded slurry being less than about 3 centimeters, the binder is thermoset to join the fibers together at their nexaes, and then the binder is carbonized to form the carbon bond. A second slurry of the fibers, binder and water is then applied over the carbonized body with the vacuum molding, binder thermosetting and carbonizing steps being repeated to form a layered insulator with the binder providing a carbon bond between the layers. The molding, thermosetting and carbonizing steps may be repeated with additional slurries until the thermal insulator is of the desired final thickness. An additional feature of the present invention is provided by incorporating opacifying materials in any of the desired layers so as to provide different insulating properties at various temperatures. Concentration and/or type of additive can be varied from layer-to-layer.

  3. Thin-layer thermal insulation coatings based on high-filled spheroplastics with polyorganosiloxane binder

    Science.gov (United States)

    Chukhlanov, V. Yu; Selivanov, O. G.; Trifonova, T. A.; Ilina, M. E.; Chukhlanova, N. V.

    2017-10-01

    Thermal insulation coatings, based on polyorganosiloxane as a binder and hollow glass microspheres, have been studied in this research. The developed materials are widely applied in various branches of science and engineering basically in construction. Components interaction processes are comprehensively studied. Spraying production methods of thin layer thermal insulation coatings have been researched. Ideal technological parameters for polyorganosiloxane coatings hardening depending on components ratio, ambient temperature, solvent and curative concentration have been determined. Stress related characteristics of constructional energy saving materials containing polyorganosiloxane have been researched. Components structure and ratio concerning compound extension strength properties have been revealed. Substantiation of Danneberg model application for the strength characteristics enhancing, when hollow microspheres are introduced, has been suggested. Thermal properties of coating thermal insulation have been studied. To research these characteristics standard methods applying devices IT-S-400 and IT-λ-400 have been chosen. Filler concentration increase was stated to decrease the composition heat conductivity coefficient and to the reduction of temperature dependence of this index. The authors suggested to employ the developed thermal insulation materials for construction and power engineering facilities operating under high temperature and other unfavorable environment.

  4. Thermally Enhanced Cable Insulation for the Nb-Ti High Luminosity LHC Inner Triplet Model

    CERN Document Server

    Granieri, P P; Richter, D; Tommasini, D

    2012-01-01

    A new concept of polyimide electrical insulation for superconducting cables of accelerator magnets was developed in the last years. Its enhanced He II permeability allows a significant improvement of the heat extraction from the coil. This cable insulation concept is used for the quadrupole magnet prototype for the insertion region of the High Luminosity - Large Hadron Collider project. It aims at pushing the limits of the Nb Ti technology to withstand high heat deposition. Cable samples wrapped with the new insulation scheme were characterized from the thermal standpoint, as well as from the electrical and mechanical ones. In particular, heat transfer measurements from insulated cables towards the helium cooling bath were performed in a coil-like configuration. Various wrapping schemes were tested in different mechanical conditions, and a model was developed to explain the experimental results. The paper summarizes the main results of all these investigations.

  5. Thermally insulating and fire-retardant lightweight anisotropic foams based on nanocellulose and graphene oxide.

    Science.gov (United States)

    Wicklein, Bernd; Kocjan, Andraž; Salazar-Alvarez, German; Carosio, Federico; Camino, Giovanni; Antonietti, Markus; Bergström, Lennart

    2015-03-01

    High-performance thermally insulating materials from renewable resources are needed to improve the energy efficiency of buildings. Traditional fossil-fuel-derived insulation materials such as expanded polystyrene and polyurethane have thermal conductivities that are too high for retrofitting or for building new, surface-efficient passive houses. Tailored materials such as aerogels and vacuum insulating panels are fragile and susceptible to perforation. Here, we show that freeze-casting suspensions of cellulose nanofibres, graphene oxide and sepiolite nanorods produces super-insulating, fire-retardant and strong anisotropic foams that perform better than traditional polymer-based insulating materials. The foams are ultralight, show excellent combustion resistance and exhibit a thermal conductivity of 15 mW m(-1) K(-1), which is about half that of expanded polystyrene. At 30 °C and 85% relative humidity, the foams retained more than half of their initial strength. Our results show that nanoscale engineering is a promising strategy for producing foams with excellent properties using cellulose and other renewable nanosized fibrous materials.

  6. A Method to have Multi-Layer Thermal Insulation Provide Damage Detection

    Science.gov (United States)

    Woodward, Stanley E.; Taylor, Bryant D.; Jones, Thomas W.; Shams, Qamar A.; Lyons, Frankel; Henderson, Donald

    2007-01-01

    Design and testing of a multi-layer thermal insulation system that also provides debris and micrometeorite damage detection is presented. One layer of the insulation is designed as an array of passive open-circuit electrically conductive spiral trace sensors. The sensors are a new class of sensors that are electrically open-circuits that have no electrical connections thereby eliminating one cause of failure to circuits. The sensors are powered using external oscillating magnetic fields. Once electrically active, they produce their own harmonic magnetic fields. The responding field frequency changes if any sensor is damaged. When the sensors are used together in close proximity, the inductive coupling between sensors provides a means of telemetry. The spiral trace design using reflective electrically conductive material provides sufficient area coverage for the sensor array to serves as a layer of thermal insulation. The other insulation layers are designed to allow the sensor s magnetic field to permeate the insulation layers while having total reflective surface area to reduce thermal energy transfer. Results of characterizing individual sensors and the sensor array s response to punctures are presented. Results of hypervelocity impact testing using projectiles of 1-3.6 millimeter diameter having speeds ranging from 6.7-7.1 kilometers per second are also presented.

  7. Thermally insulating and fire-retardant lightweight anisotropic foams based on nanocellulose and graphene oxide

    Science.gov (United States)

    Wicklein, Bernd; Kocjan, Andraž; Salazar-Alvarez, German; Carosio, Federico; Camino, Giovanni; Antonietti, Markus; Bergström, Lennart

    2015-03-01

    High-performance thermally insulating materials from renewable resources are needed to improve the energy efficiency of buildings. Traditional fossil-fuel-derived insulation materials such as expanded polystyrene and polyurethane have thermal conductivities that are too high for retrofitting or for building new, surface-efficient passive houses. Tailored materials such as aerogels and vacuum insulating panels are fragile and susceptible to perforation. Here, we show that freeze-casting suspensions of cellulose nanofibres, graphene oxide and sepiolite nanorods produces super-insulating, fire-retardant and strong anisotropic foams that perform better than traditional polymer-based insulating materials. The foams are ultralight, show excellent combustion resistance and exhibit a thermal conductivity of 15 mW m-1 K-1, which is about half that of expanded polystyrene. At 30 °C and 85% relative humidity, the foams retained more than half of their initial strength. Our results show that nanoscale engineering is a promising strategy for producing foams with excellent properties using cellulose and other renewable nanosized fibrous materials.

  8. Evidence for thermal activation in the glassy dynamics of insulating granular aluminum conductance

    Science.gov (United States)

    Grenet, T.; Delahaye, J.

    2017-11-01

    Insulating granular aluminum is one of the proto-typical disordered insulators whose low temperature electrical conductance exhibits ubiquitous non-equilibrium phenomena. These include slow responses to temperature or gate voltage changes, characteristic field effect anomalies and ageing phenomena typical of a glass. In this system the influence of temperature on the glassy dynamics has remained elusive. A similar situation was met in insulating indium oxide and it was concluded that in high carrier density Anderson insulators, electronic slow relaxations essentially proceed via activationless processes. In this work we experimentally demonstrate that thermal effects do play a role and that the slow dynamics in granular aluminum is subject to thermal activation. We show how its signatures can be revealed and activation energy distributions can be extracted, providing a promising grasp on the nature of the microscopic mechanism at work in glassy Anderson insulators. We explain why some of the experimental protocols previously used in the literature fail to reveal thermal activation in these systems. Our results and analyses call for a reassessment of the emblematic case of indium oxide, and question the existence of purely activationless dynamics in any of the systems studied so far.

  9. Benefits of the use of thermal insulation in a naturally ventilated residential building in Brazilian temperate climate

    OpenAIRE

    Vinícius Linczuk; Fernando Simon Westphal

    2016-01-01

    The use of thermal insulation is not a common practice in civil construction in Brazil. The national standard for thermal performance and the energy efficiency labeling program do not require the use of thermal insulation in the building envelope, even for the hottest and for the coldest regions of the country. Brazil has a temperate climate region that covers 7.2% of its territory and contains important and populous cities. This paper explores the benefits of the use of thermal i...

  10. Mineral purity command. Thermal insulation and design using a rockwool system; Mineralisches Reinheitsgebot. Daemmen und Gestalten mit Steinwolle im System

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2011-10-15

    A former brewery was converted into exhibition rooms for high-quality office furniture. The historical building was maintained, and the thermal insulation and fire protection concepts were modernized. Rockwool was used for the project as it combines the advantages of efficient thermal insulation with those of a wide and well-matched product range.

  11. Mechanically Stretchable and Electrically Insulating Thermal Elastomer Composite by Liquid Alloy Droplet Embedment

    Science.gov (United States)

    Jeong, Seung Hee; Chen, Si; Huo, Jinxing; Gamstedt, Erik Kristofer; Liu, Johan; Zhang, Shi-Li; Zhang, Zhi-Bin; Hjort, Klas; Wu, Zhigang

    2015-01-01

    Stretchable electronics and soft robotics have shown unsurpassed features, inheriting remarkable functions from stretchable and soft materials. Electrically conductive and mechanically stretchable materials based on composites have been widely studied for stretchable electronics as electrical conductors using various combinations of materials. However, thermally tunable and stretchable materials, which have high potential in soft and stretchable thermal devices as interface or packaging materials, have not been sufficiently studied. Here, a mechanically stretchable and electrically insulating thermal elastomer composite is demonstrated, which can be easily processed for device fabrication. A liquid alloy is embedded as liquid droplet fillers in an elastomer matrix to achieve softness and stretchability. This new elastomer composite is expected useful to enhance thermal response or efficiency of soft and stretchable thermal devices or systems. The thermal elastomer composites demonstrate advantages such as thermal interface and packaging layers with thermal shrink films in transient and steady-state cases and a stretchable temperature sensor. PMID:26671673

  12. Design parameters for single pipe thermal insulation systems for offshore flow assurance

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Adam; Johnsen, Erik; Kopystynski, Adam; Simonsen, Eirik; Boye-Hansen, Allan [Bredero Shaw (Thermotite), Orkanger (Norway)

    2005-07-01

    Limit state design of subsea thermal insulation systems has been shown to be feasible and robust. This requires careful implementation of extensive long-term laboratory data and property models into verified FEA / FDA tools. Such simulations allow for the determination of not only the steady state response, but also the transient response of the system as a function of temperature, hydrostatic loading, ageing, water ingress and time. This departure from the traditional use of monolithic thermal conductivities, heat capacities and water absorption values can allow in some cases for a reduction in the thickness of insulation, whilst simultaneously enabling control of conservatism. The current paper discusses the important influences affecting the performance of insulant systems and the results of verification testing along with design examples where the generally accepted design method is compared to the limit state approach. (author)

  13. Thermal Jacket Design Using Cellulose Aerogels for Heat Insulation Application of Water Bottles

    Directory of Open Access Journals (Sweden)

    Hai M. Duong

    2017-11-01

    Full Text Available Thermal jacket design using eco-friendly cellulose fibers from recycled paper waste is developed in this report. Neoprene as an outmost layer, cellulose aerogels in the middle and Nylon as an innermost layer can form the best sandwiched laminate using the zigzag stitching method for thermal jacket development. The temperature of the ice slurry inside the water bottle covered with the designed thermal jackets remains at 0.1 °C even after 4 h, which is the average duration of an outfield exercise. Interestingly, the insulation performance of the designed thermal jackets is much better than the commercial insulated water bottles like FLOE bottles and is very competition to that of vacuum flasks for a same period of 4 h and ambient conditions.

  14. A Literature Review of Sealed and Insulated Attics—Thermal, Moisture and Energy Performance

    Energy Technology Data Exchange (ETDEWEB)

    Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-08-01

    In this literature review and analysis, we focus on the thermal, moisture and energy performance of sealed and insulated attics in California climates. Thermal. Sealed and insulated attics are expected to maintain attic air temperatures that are similar to those in the house within +/- 10°F. Thermal stress on the assembly, namely high shingle and sheathing temperatures, are of minimal concern. In the past, many sealed and insulated attics were constructed with insufficient insulation levels (~R-20) and with too much air leakage to outside, leading to poor thermal performance. To ensure high performance, sealed and insulated attics in new California homes should be insulated at levels at least equivalent to the flat ceiling requirements in the code, and attic envelopes and ducts should be airtight. We expect that duct systems in well-constructed sealed and insulated attics should have less than 2% HVAC system leakage to outside. Moisture. Moisture risk in sealed and insulated California attics will increase with colder climate regions and more humid outside air in marine zones. Risk is considered low in the hot-dry, highly populated regions of the state, where most new home construction occurs. Indoor humidity levels should be controlled by following code requirements for continuous whole-house ventilation and local exhaust. Pending development of further guidance, we recommend that the air impermeable insulation requirements of the International Residential Code (2012) be used, as they vary with IECC climate region and roof finish. Energy. Sealed and insulated attics provide energy benefits only if HVAC equipment is located in the attic volume, and the benefits depend strongly on the insulation and airtightness of the attic and ducts. Existing homes with leaky, uninsulated ducts in the attic should have major savings. When compared with modern, airtight duct systems in a vented attic, sealed and insulated attics in California may still provide substantial benefit

  15. Thermal Insulation Performance of Textile Structures for Spacesuit Applications at Martian Pressure and Temperature

    Science.gov (United States)

    Orndoff, Evelyne; Trevino, Luis A.

    2000-01-01

    Protection of astronauts from the extreme temperatures in the space environment has been provided in the past using multi-layer insulation in ultra-high vacuum environments of low earth orbit and the lunar surface. For planetary environments with residual gas atmospheres such as Mars with ambient pressures between 8 to 14 hPa (8 to 14 mbar), new protection techniques are required because of the dominating effect of the ambient gas on heat loss through the insulation. At Mars ambient pressure levels, the heat loss can be excessive at expected suit external temperatures of 172 K with state-of-the-art suit insulation, requiring an active heat source and its accompanying weight and volume penalties. Micro-fibers have been identified as one potential structure to reduce the heat losses, but existing fundamental data on fiber heat transfer at low pressure is lacking for integrated fabric structures. This baseline study presents insulation performance test data at different pressures and fabric loads for selected polyesters and aramids as a function of fiber density, fiber diameter, fabric density, and fabric construction. A set of trend data of thermal conductivity versus ambient pressure is presented for each fiber and fabric construction design to identify the design effects on thermal conductivity at various ambient pressures, and to select a fiber and fabric design for further development as a suit insulation. The trend data also shows the pressure level at which thermal conductivity approaches a minimum, below which no further improvement is possible for a given fiber and fabric design. The pressure levels and resulting thermal conductivities from the trend data can then be compared to the ambient pressure at a planetary surface, Mars for example, to determine if a particular fiber and fabric design has potential as a suit insulation.

  16. STS-40 Columbia, OV-102, payload bay aft firewall and thermal insulation

    Science.gov (United States)

    1991-01-01

    STS-40 Columbia, Orbiter Vehicle (OV) 102, payload bay (PLB) aft firewall is documented to show a loose piece of thermal insulation. The crew discovered the loose blanket soon after opening the PLB doors on 06-05-91. The vertical tail and the left orbital maneuvering system (OMS) pod are visible above the bulkhead.

  17. Thermal properties of a sandwich construction insulated with Polyurethane (DC-System)

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Dreau, Jerome Le

    conductivity: + 50% for expanded polystyrene (λ ≈ 30 mW/m.K), + 75% for mineral wools (λ ≈ 35 mW/m.K), etc. Despite its low thermal conductivity, polyurethane foam (PUR) is not much used as insulation material for walls because of its low resistance to fire. The most common PUR boards are classified C-s2-d0...

  18. Use of XPS thermal insulator boards in design of educational spaces

    African Journals Online (AJOL)

    Heating and cooling equipment capacity becomes smaller than half after proper implementation of thermal insulation. As air conditioning equipment becomes small, implementation of optimization not only becomes free but also reduces the overall cost of construction. Keywords: School, modern materials, Building and ...

  19. Model-based analysis of thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2014-01-01

    conducted exploring the effects of the following parameters: pigment (hollow spheres) volume concentration (PVC), average sphere size or sphere size distribution, thermal conductivities of binder and sphere wall material, and sphere wall thickness. All the parameters affected the thermal conductivity...... of an epoxy coating, but simulations revealed that the most important parameters are the PVC, the sphere wall thickness, and the sphere wall material. The model can be used, qualitatively, to get an indication of the effect of important model parameters on the thermal conductivity of an HS-based coating...

  20. Determination of physical properties of fibrous thermal insulation

    Directory of Open Access Journals (Sweden)

    Jeandel G.

    2012-10-01

    Full Text Available The objective of this study is to characterize both experimentally and theoretically, conductive and radiative heat transfer within polyester batting. This material is derived from recycled bottles (PET with fibres of constant diameters. Two other mineral and plant fibrous insulation materials, (glass wool and hemp wool are also characterized for comparative purposes. To determine the overall thermophysical properties of the tested materials, heat flux measurement are carried out using a device developed in house. The radiative properties of the material are determined by an inverse method based on measurements of transmittance and reflectance using a FTIR spectrometer and by solving the equation of radiative heat transfer. These measures are compared to results of numerical simulations.

  1. Effect of posture positions on the evaporative resistance and thermal insulation of clothing.

    Science.gov (United States)

    Wu, Y S; Fan, J T; Yu, W

    2011-03-01

    Evaporative resistance and thermal insulation of clothing are important parameters in the design and engineering of thermal environments and functional clothing. Past work on the measurement of evaporative resistance of clothing was, however, limited to the standing posture with or without body motion. Information on the evaporative resistance of clothing when the wearer is in a sedentary or supine posture and how it is related to that when the wearer is in a standing posture is lacking. This paper presents original data on the effect of postures on the evaporative resistance of clothing, thermal insulation and permeability index, based on the measurements under three postures, viz. standing, sedentary and supine, using the sweating fabric manikin-Walter. Regression models are also established to relate the evaporative resistance and thermal insulation of clothing under sedentary and supine postures to those under the standing posture. The study further shows that the apparent evaporated resistances of standing and sedentary postures measured in the non-isothermal condition are much lower than those in the isothermal condition. The apparent evaporative resistances measured using the mass loss method are generally lower than those measured using the heat loss method due to moisture absorption or condensation within clothing. STATEMENT OF RELEVANCE: The thermal insulation and evaporative resistance values of clothing ensembles under different postures are essential data for the ergonomics design of thermal environments (e.g. indoors or a vehicle's interior environment) and functional clothing. They are also necessary for the prediction of thermal comfort or duration of exposure in different environmental conditions.

  2. Total heat loss coefficient of flat roof constructions with external insulation in tapered layers including the effects of thermal bridges

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    In order to achieve durability of flat roofs with external insulation, it is necessary to secure proper drainage of the roof, i.e. to avoid water leaking into the insulation. The design of the tapered insulation of the roof is quite difficult as requirements with respect to both drainage and insu...... for design of flat roofs and a pc-program that can be used for calculating the total heat loss coefficient of externally insulated roofs with insulation in tapered layers, taking into account thermal bridges in the roof construction....

  3. Insulation commonality assessment (phase 1). Volume 2: Section 7.0 through 16.0. [evaluation of materials used for spacecraft thermal insulation

    Science.gov (United States)

    1973-01-01

    The heat transfer characteristics of various materials used for the thermal insulation of spacecraft are discussed. Techniques for conducting thermal performance analysis, structural performance analysis, and dynamic analysis are described. Processes for producing and finishing the materials are explained. The methods for determining reliability, system safety, materials tests, and design effectiveness are explained.

  4. Tubular House - Form Follows Technology, Concrete Shell Structure with Inner Thermal Insulation

    Science.gov (United States)

    Idem, Robert; Kleczek, Paweł; Pawłowski, Krzysztof; Chudoba, Piotr

    2017-10-01

    The aim of this paper is the theoretical analysis of the possibilities and limitations of using an unconventional technology and the original architectural form stemming from it – the building with external construction and internal insulation. In Central European climatic conditions, the traditional solution for the walls of heated buildings relies on using external thermal insulation. This stems from building physics: it prevents interstitial condensation of water vapour in the wall. Internal insulation is used exceptionally. This is done e.g. in historical buildings undergoing thermal modernization (due to the impossibility of interfering with facade). In such cases, a thermal insulation layer is used on the internal wall surface, along with an additional layer of vapour barrier. The concept of building concerns the intentional usage of an internal insulation. In this case, the construction is a tight external reinforced concrete shell. The architectural form of such building is strongly interrelated with the technology, which was used to build it. The paper presents the essence of this concept in descriptive and drawing form. The basic elements of such building are described (the external construction, the internal insulation and ventilation). As a case study, authors present a project of a residential building along with the description of the applied materials and installation solutions, and the results obtained from thermal, humidity and energetic calculations. The discussion presents the advantages and disadvantages of the proposed concept. The basic advantage of this solution is potentially low building cost. This stems from minimizing the ground works, the simplicity of the joints and the outer finish, as well as from the possibility of prefabrication of the elements. The continuity of the thermal insulation allows to reduce the amount of thermal bridges. The applied technology and form are applicable most of all for small buildings, due to limited

  5. Evaluation of thermal insulation and mechanical properties of waste rubber/natural rubber composite

    Directory of Open Access Journals (Sweden)

    M.M. Abdel Kader

    2012-04-01

    Full Text Available The influences of waste rubber loading on mechanical and thermal conductivity properties were investigated for NR composite. An experimental investigation was carried out to obtain low cost construction material with desirable mechanical and thermal insulation properties. Natural rubber was loaded with different concentrations of waste rubber (200, 400, 600, 800, and 1000 phr. The addition of waste rubber leads to a slight increase in thermal conductivity values of composites but it still lies around range of thermal insulating materials. Also addition of waste rubber leads to improvement of mechanical properties of composites. The crosslink density of NR composite increases with the increase of waste rubber loading until 600 phr and after that it decreases due to the stronger the rubber–filler interaction. This leads to the decrease of the swelling index that has the opposite trend of crosslink density. So, the sample with 600 phr waste rubber is considered the optimum concentration from the swelling measurement. Filler loading results in pronounced increase in the tensile modulus and decease in the elongation at fracture which reflects the reinforcement effect of the filler. The yield stress increases with waste rubber loading increment. This delays the permanent disruption of matrix morphology. So, the optimum concentration which is 600 phr waste rubber loading agrees with the swelling and mechanical measurements which has desirable thermal insulation and high mechanical properties and decreases the cost of materials to 82% of the NR cost.

  6. Nanoporous Silica Thermal Insulation for Space Shuttle Cryogenic Tanks: A Case Study

    Science.gov (United States)

    Noever, David A.

    1999-01-01

    Nanoporous silica (with typical 10-50 nm porous radii) has been benchmarked for thermal insulators capable of maintaining a 150 K/cm temperature gradient. For cryogenic use in aerospace applications, the combined features for low-density, high thermal insulation factors, and low temperature compatibility are demonstrated in a prototype sandwich structure between two propulsion tanks. Theoretical modelling based on a nanoscale fractal structure suggest that the thermal conductivity scales proportionally (exponent, 1.7) with the material density-lower density increases the thermal insulation rating. Computer simulations, however, support the optimization tradeoff between material strength (Young moduli, proportional to density with exponent, 3.7), the characteristic (colloidal silica, less than 5 nm) particle size, and the thermal rating. The results of these simulations indicate that as nanosized particles are incorporated into the silica backbone, the resulting physical properties will be tailored by the smallest characteristic length and their fractal interconnections (dimension and fractal size). The application specifies a prototype panel which takes advantage of the processing flexibility inherent in sol-gel chemistry.

  7. Production of thermal insulation blocks from bottom ash of fluidized bed combustion system.

    Science.gov (United States)

    Mandal, A K; Sinha, O P

    2017-08-01

    The issues of disposal and environmental problems are increased by the generation of bottom ash from the thermal power plants day by day; hence, its recycling is required. The present study aimed to make thermal insulation blocks using as raw material bottom ash and iron ore slime as a binder and to characterize their engineering properties. Two different fineness values of bottom ash were considered with varying amounts of iron ore slime (0-10%) to make the blocks. Blocks were dried followed by firing at 1000, 1100 and 1200°C, respectively. Cold crushing strength, density and thermal conductivity of these fired blocks showed increasing behaviour with firing temperature, fineness of bottom ash and iron ore slime content. In contrast, a reverse trend was observed in the case of porosity. With increasing firing temperature, the formation of lower melting phases like iron silicate followed by iron aluminium silicate was observed, which imparts the strength inside the blocks. The coarser particles of bottom ash increase the interparticle spaces, which enhances the apparent porosity, resulting in higher thermal insulation property in the blocks. Blocks having better thermal insulation property could be possible to make effectively from coarse bottom ash by adding iron ore slime as a binder.

  8. Thermal transmittance of reed-insulated walls in a purpose-built test house

    Directory of Open Access Journals (Sweden)

    M. Miljan

    2014-03-01

    Full Text Available We studied the construction and thermal properties of walls insulated with reed, to enable comparisons with other wall structures that are widely used in building. In 2010 we built a test house insulated with reed adjacent to the Estonian University of Life Sciences in Tartu. The load-bearing structure of the house was a timber frame, and four different technologies were used to place reed insulation in its external walls. The thickness of the reed layer was 450 mm in all cases, and both sides (inside and outside of the walls were rendered with clay plaster. Records were kept of time spent and materials used in construction of the different types of walls, and these data were used to calculate unit (m-2 requirements of time and materials for each wall type to enable direct comparisons. From October 2010 to March 2012, heat flow plates were used to measure the thermal transmittance of the walls of the completed house and the results were compared with the thermal transmittance requirements set by Estonian legislation. Only one of the test walls met the Estonian standard. This was insulated with compressed loose reed, placed horizontally in the wall.

  9. Thermal Insulation Performance of Flexible Piping for Use in HTS Power Cables

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, S. D.; Demko, J. A.; Thompson, Karen (Technical Monitor)

    2001-01-01

    High-temperature superconducting (HTS) cables that typically operate at temperatures below 80 K are being developed for power transmission. The practical application of HTS power cables will require the use of flexible piping to contain the cable and the liquid nitrogen coolant. A study of thermal performance of multilayer insulation (MLI) was conducted in geometries representing both rigid and flexible piping. This experimental study performed at the Cryogenics Test Laboratory of NASA Kennedy Space Center provides a framework for the development of cost-effective, efficient thermal insulation systems that will support these long-distance flexible lines containing HTS power cables. The overall thermal performance of the insulation system for a rigid configuration and for a flexible configuration, simulating a flexible HTS power cable, was determined by the steady-state liquid nitrogen boiloff method under the full range of vacuum levels. Two different cylindrically rolled material systems were tested: a standard MLI and a layered composite insulation (LCI). Comparisons of ideal MLI, MLI on rigid piping, and MLI between flexible piping are presented.

  10. Thermal conductivity of magnetic insulators with strong spin-orbit coupling

    Science.gov (United States)

    Stamokostas, Georgios; Lapas, Panteleimon; Fiete, Gregory A.

    We study the influence of spin-orbit coupling on the thermal conductivity of various types of magnetic insulators. In the absence of spin-orbit coupling and orbital-degeneracy, the strong-coupling limit of Hubbard interactions at half filling can often be adequately described in terms of a pure spin Hamiltonian of the Heisenberg form. However, in the presence of spin-orbit coupling the resulting exchange interaction can become highly anisotropic. The effect of the atomic spin-orbit coupling, taken into account through the effect of magnon-phonon interactions and the magnetic order and excitations, on the lattice thermal conductivity of various insulating magnetic systems is studied. We focus on the regime of low temperatures where the dominant source of scattering is two-magnon scattering to one-phonon processes. The thermal current is calculated within the Boltzmann transport theory. We are grateful for financial support from NSF Grant DMR-0955778.

  11. Transparent thermal insulation for prefabricated school buildings; Einsatz transparenter Waermedaemmung an Schulgebaeuden in praefabrizierter Bauweise

    Energy Technology Data Exchange (ETDEWEB)

    Russ, C. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany). Gruppe Solares Bauen; Buchmann, R. [Leipzigprojekt GmbH, Leipzig (Germany); Duesterhoeft, A. [Holz- und Leichtmetallbau GmbH, Leipzig (Germany)

    1997-12-31

    The existing schools in the new federal states built from prefabricated elements need to be modernized in order to reduce their energy demand. Fitting some 300 square metres of transparent thermal insulation to the south side of a house front may lead to a cut in its thermal energy demand by 74 per cent. This energy consumption is by 12 kWh per square metre lower than the one obtained with opaque thermal insulation. The results of the first demonstration project are described. (MSK) [Deutsch] Die in den neuen Bundeslaendern vorhandenen Schulen in vorgefertigter Bauweise sind energetisch sanierungsbeduerftig. Werden im Rahmen einer Sanierung ca. 300qm transparente Waermedaemmung an der suedorientierten Fassade eingesetzt, so kann der Heizwaermebedarf um 74% herabgesetzt werden. Das sind 12 kWh/qm weniger als bei dem vergleichsweisen Einsatz einer opaken Waermedaemmung. Im Folgenden werden die Ergebnisse des ersten Demonstrationsprojekts beschrieben.

  12. Data on anti-insulation detection via Point of Thermal Inflexion (PTI in 1248 cases; 13 climates, four occupancy profiles, six wall configurations and four insulation levels

    Directory of Open Access Journals (Sweden)

    Yasin M. Idris

    2017-06-01

    Full Text Available The data in this article are the simulation results of 1248 cases that were carried out to detect anti-insulation behaviour in the article titled “Anti-insulation mitigation by altering the envelope layers’ configuration” (Idris and Mae, 2017 [1]. These cases are generated by a matrix of 13 climates, 6 envelope layer configurations, 4 occupancy profiles and 4 levels of insulation thickness. The data are concerned with the annual cooling and heating loads of these cases. In addition, the data include the Point of Thermal Inflexion (PTI values and their anti-insulation pattern, when PTI is found. The PTI values are compiled in a single summary file and supplied as well. All These data are shared via this article where they can be reused in different ways, but mainly for serving researchers that intend to approach anti-insulation behaviour from different points of view.

  13. Data on anti-insulation detection via Point of Thermal Inflexion (PTI) in 1248 cases; 13 climates, four occupancy profiles, six wall configurations and four insulation levels.

    Science.gov (United States)

    Idris, Yasin M; Mae, Masayuki

    2017-06-01

    The data in this article are the simulation results of 1248 cases that were carried out to detect anti-insulation behaviour in the article titled "Anti-insulation mitigation by altering the envelope layers' configuration" (Idris and Mae, 2017) [1]. These cases are generated by a matrix of 13 climates, 6 envelope layer configurations, 4 occupancy profiles and 4 levels of insulation thickness. The data are concerned with the annual cooling and heating loads of these cases. In addition, the data include the Point of Thermal Inflexion (PTI) values and their anti-insulation pattern, when PTI is found. The PTI values are compiled in a single summary file and supplied as well. All These data are shared via this article where they can be reused in different ways, but mainly for serving researchers that intend to approach anti-insulation behaviour from different points of view.

  14. Arcjet Testing and Thermal Model Development for Multilayer Felt Reusable Surface Insulation

    Science.gov (United States)

    Milos, Frank S.; Scott, Carl Douglas; Papa, Steven V.

    2012-01-01

    Felt Reusable Surface Insulation was used extensively on leeward external surfaces of the Shuttle Orbiter, where the material is reusable for temperatures up to 670 K. For application on leeward surfaces of the Orion Multi-Purpose Crew Vehicle, where predicted temperatures reach 1620 K, the material functions as a pyrolyzing conformal ablator. An arcjet test series was conducted to assess the performance of multilayer Felt Reusable Surface Insulation at high temperatures, and a thermal-response, pyrolysis, and ablation model was developed. Model predictions compare favorably with the arcjet test data

  15. Flat-plate boiloff calorimeters for testing of thermal insulation systems

    Science.gov (United States)

    Fesmire, J. E.; Johnson, W. L.; Kelly, A. O.; Meneghelli, B. J.; Swanger, A. M.

    2015-12-01

    Cryostats have been developed and standardized for laboratory testing of thermal insulation systems in a flat-plate configuration. Boiloff calorimetry is the measurement principle for determining the effective thermal conductivity (ke) and heat flux (q) of test specimens under a wide range of actual conditions. Cryostat-500 is thermally guarded to measure absolute thermal performance when calibrated with a known reference via an adjustable-edge guard ring. With liquid nitrogen as the energy meter, the cold boundary temperature can be adjusted to any temperature between 77 K and approximately 300 K by the interposition of a thermal resistance layer between the cold mass and the specimen. A low thermal conductivity suspension system has compliance rods that adjust for specimen thickness and compression force. Material type, thickness, density, flatness, compliance, outgassing, and temperature sensor placement are important test considerations, and edge effects and calibration techniques for the apparatus are crucial. Over the full vacuum pressure range, the thermal performance capability is nearly four orders of magnitude. The horizontal configuration provides key advantages over the vertical cylindrical cryostats for testing at ambient pressure conditions. Cryostat-500’s design and test methods, other flat-plate boiloff calorimeters, and results for select thermal insulation materials (composites, foams, aerogels) are discussed.

  16. Adiabatic and thermally insulated: should they have the same meaning?

    Science.gov (United States)

    Anacleto, Joaquim; Ferreira, J. M.

    2018-01-01

    Symmetries regarding system-surroundings interchange are used to propose the attribution of different meanings to the terms ‘adiabatic’ and ‘thermally insulated’ and address the resulting implications. It is also shown that entropy generation can be interpreted as the ratio of lost work by the temperature at which such loss occurs, and that it occurs always in the system.

  17. Effect of resin infiltration on the thermal and mechanical properties of nano-sized silica-based thermal insulation.

    Science.gov (United States)

    Lee, Jae Chun; Kim, Yun-Il; Lee, Dong-Hun; Kim, Won-Jun; Park, Sung; Lee, Dong Bok

    2011-08-01

    Several kinds of nano-sized silica-based thermal insulation were prepared by dry processing of mixtures consisting of fumed silica, ceramic fiber, and a SiC opacifier. Infiltration of phenolic resin solution into the insulation, followed by hot-pressing, was attempted to improve the mechanical strength of the insulation. More than 22% resin content was necessary to increase the strength of the insulation by a factor of two or more. The structural integrity of the resin-infiltrated samples could be maintained, even after resin burn-out, presumably due to reinforcement from ceramic fibers. For all temperature ranges and similar sample bulk density values, the thermal conductivities of the samples after resin burn-out were consistently higher than those of the samples obtained from the dry process. Mercury intrusion curves indicated that the median size of the nanopores formed by primary silica aggregates in the samples after resin burn-out is consistently larger than that of the sample without resin infiltration.

  18. Assessment of thermal insulation materials and systems for building applications

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    The primary goal of the study was to provide a proper foundation for decision making by the federal government, industry, and consumer. The report may be used to identify areas where new test methods and standards are needed to establish new programs for improving thermal performance of buildings, and as a basis for setting new or improved standards after the recommended test programs have been completed.

  19. Thermal stress analysis of reusable surface insulation for shuttle

    Science.gov (United States)

    Ojalvo, I. U.; Levy, A.; Austin, F.

    1974-01-01

    An iterative procedure for accurately determining tile stresses associated with static mechanical and thermally induced internal loads is presented. The necessary conditions for convergence of the method are derived. An user-oriented computer program based upon the present method of analysis was developed. The program is capable of analyzing multi-tiled panels and determining the associated stresses. Typical numerical results from this computer program are presented.

  20. Application of Nanofiber Technology to Nonwoven Thermal Insulation

    OpenAIRE

    Phillip W. Gibson, Ph.D; Calvin Lee, Ph.D; Frank Ko, Ph.D.; Darrell Reneker, Ph.D.

    2007-01-01

    Nanofiber technology (fiber diameter less than 1 micrometer) is under development for future Army lightweight protective clothing systems. Nanofiber applications for ballistic and chemical/biological protection are being actively investigated, but the thermal properties of nanofibers and their potential protection against cold environments are relatively unknown. Previous studies have shown that radiative heat transfer in fibrous battings is minimized at fiber diameters between 5 and 10 micro...

  1. Environmental cycling of cellulosic thermal insulation and its influence on fire performance

    Science.gov (United States)

    Lawson, J. R.

    1984-08-01

    A study was conducted on climatological data for eleven cities located throughout the United States. Findings from this environmental study were used to develop conditioning cycles for a research project on the influence of environments on the fire performance of loose-fill cellulosic thermal insulation. Six cellulosic insulation materials with different compositions of fire retardant chemicals at an add-on level of 25% by weight were specially manufactured for this study. These materials were tested for fire performance using the smoldering combustion test and the attic flooring radiant panel test to establish a baseline. After the materials were exposed to the various environmental cycles, they were tested for fire performance. Results from these tests show that environmental exposure can have a significant effect on the fire performance of cellulosic insulation materials and indicates that long term fire protection provided by fire retardant compounds may be limited.

  2. Utilization of Baggase Waste Based Materials as Improvement for Thermal Insulation of Cement Brick

    Directory of Open Access Journals (Sweden)

    Aminudin Eeydzah

    2017-01-01

    Full Text Available Building materials having low thermal load and low thermal conductivity will provide thermal comforts to the occupants in building. In an effort to reduce the use of high energy and waste products from the agricultural industry, sugarcane bagasse and banana bagasse has been utilize as an additive in the manufacture of cement brick. The aim of this study is to investigate the insulation and mechanical properties of brick that has been mixed with bagasse and its effectiveness as thermal insulation using heat flow meter. Waste bagasse is being treated using sodium hydroxide (NaOH and is characterized using SEM and XRF. The samples produced with two different dimensions of 50 mm × 50 mm × 50 mm and 215mm × 102.5mm × 65mm for thermal conductivity test. Next, the sample varies from 0% (control sample, 2%, 4%, 6%, 8% and 10% in order to determine the best mix proportion. The compressive strength is being tested for 7, 14 and 28 days of water curing. Results showed that banana bagasse has lower thermal conductivity compared to sugarcane bagasse used, with compressive strength of 15.6MPa with thermal conductivity 0.6W/m.K.

  3. RESEARCHES REGARDING USE OF TEXTILE MATERIALS FOR THERMAL INSULATION AT NEGATIVE TEMPERATURES

    Directory of Open Access Journals (Sweden)

    IOSUB Andrei

    2014-05-01

    Full Text Available Using thermal insulation in negative temperature acts to reduce heat flow to the cooled space or to objects that have a temperature below ambient temperature. To achieve economic operation of the space to be cooled insulation thickness and quality is an important factor. In this article we want to compare three products used in thermal insulation at negative temperatures: expanded polystyrene, non-woven and wool coats. The materials will be tested with a mechanical vapor compression refrigerator capable of producing temperatures in the range +4 .. -35 ° C, managed by a programmer Dixel capable of recording values between +40. .. -60 °C. Refrigeration insulation enclosure was made with 100 mm expanded polystyrene. On one side of the enclosure will be a cut of 250 * 250 mm, chosen in a central position where the material will be introduced to be tested. The dimensions of the samples are 250 * 250 * 60 mm. To check the insulation properties of materials it will be used a temperature logger capable of recording with two probes temperatures between +125...-40° C. One of the probes will be inserted inside the refrigerator and the second probe will be positioned to the outside of the test material adhered to an aluminum plate, in order to read a average temperature. The difference in thickness of the insulation shall be filled with non-woven material. Hardening the assembly will be made using a 6 mm thick OSB board. The materials will be tested in an identical ambient temperature and humidity.

  4. Experimental Study on Hygrothermal Deformation of External Thermal Insulation Cladding Systems with Glazed Hollow Bead

    Directory of Open Access Journals (Sweden)

    Houren Xiong

    2016-01-01

    Full Text Available This research analyzes the thermal and strain behavior of external thermal insulation cladding systems (ETICS with Glazed Hollow Beads (GHB thermal insulation mortar under hygrothermal cycles weather test in order to measure its durability under extreme weather (i.e., sunlight and rain. Thermometers and strain gauges are placed into different wall layers to gather thermal and strain data and another instrument measures the crack dimensions after every 4 cycles. The results showed that the finishing coat shrank at early stage (elastic deformation and then the finishing coat tends to expand and become damaged at later stage (plastic deformation. The deformation of insulation layer is similar to that of the finishing coat but its variation amplitude is smaller. Deformation of substrate expanded with heat and contracted with cold due to the small temperature variation. The length and width of cracks on the finishing coat grew as the experiment progressed but with a decreasing growth rate and the cracks stopped growing around 70 cycles.

  5. ONE-DIMENSIONAL NUMERICAL ANALYSIS OF THE TRANSIENT THERMAL RESPONSE OF MULTILAYER INSULATIVE SYSTEMS

    Science.gov (United States)

    Pittman, C. M.

    1994-01-01

    This program performs a one-dimensional numerical analysis of the transient thermal response of multi-layer insulative systems. The analysis can determine the temperature distribution through a system consisting of from one to four layers, one of which can be an air gap. Concentrated heat sinks at any interface can be included. The computer program based on the analysis will determine the thickness of a specified layer that will satisfy a temperature limit criterion at any point in the insulative system. The program will also automatically calculate the thickness at several points on a system and determine the total system mass. This program was developed as a tool for designing thermal protection systems for high-speed aerospace vehicles but could be adapted to many areas of industry involved in thermal insulation systems. In this package, the equations describing the transient thermal response of a system are developed. The governing differential equation for each layer and boundary condition are put in finite-difference form using a Taylor's series expansion. These equations yield an essentially tridiagonal matrix of unknown temperatures. A procedure based on Gauss' elimination method is used to solve the matrix. This program is written in FORTRAN IV for the CDC RUN compiler and has been implemented on a CDC 6000 series machine operating under SCOPE 3.0. This program requires a minimum of 44K (octal) of 60 bit words of memory.

  6. Modeling thermal performance of exterior walls retrofitted from insulation and modified laterite based bricks materials

    Science.gov (United States)

    Wati, Elvis; Meukam, Pierre; Damfeu, Jean Claude

    2017-12-01

    Uninsulated concrete block walls commonly found in tropical region have to be retrofitted to save energy. The thickness of insulation layer used can be reduced with the help of modified laterite based bricks layer (with the considerably lower thermal conductivity than that of concrete block layer) during the retrofit building fabrics. The aim of this study is to determine the optimum location and distribution of different materials. The investigation is carried out under steady periodic conditions under the climatic conditions of Garoua in Cameroon using a Simulink model constructed from H-Tools (the library of Simulink models). Results showed that for the continuous air-conditioned space, the best wall configuration from the maximum time lag, minimum decrement factor and peak cooling transmission load perspective, is dividing the insulation layer into two layers and placing one at the exterior surface and the other layer between the two different massive layers with the modified laterite based bricks layer at the interior surface. For intermittent cooling space, the best wall configuration from the minimum energy consumption depends on total insulation thickness. For the total insulation thickness less than 8 cm approximately, the best wall configuration is placing the half layer of insulation material at the interior surface and the other half between the two different massive layers with the modified earthen material at the exterior surface. Results also showed that, the optimum insulation thickness calculated from the yearly cooling transmission (estimated only during the occupied period) and some economic considerations slightly depends on the location of that insulation.

  7. Bio-susceptibility of materials and thermal insulation systems used for historical buildings

    Science.gov (United States)

    Sterflinger, Katja; Ettenauer, Joerg; Pinar, Guadalupe

    2013-04-01

    In historical buildings of Northern countries high levels of energy are necessary to reach comfortable temperatures especially during the cold season. For this reason historical buildings are now also included in country specific regulations and ordinances to enhance the "energy - efficiency". Since an exterior insulation - as it is commonly used for modern architecture - is incompatible with monument protection, several indoor insulation systems based on historical and ecological materials, are on the market that should improve the thermic performance of a historical building. However, using organic materials as cellulose, loam, weed or wood, bears the risk of fungal growth and thus may lead to health problems in indoor environments. For this reason 5 different ecological indoor insulations systems were tested for their bio-susceptibility against various fungi both under natural conditions - after 2 years of installation in an historical building - and under laboratory conditions with high levels of relative humidity. Fungal growth was evaluated by classical isolation and cultivation as well as by molecular methods. The materials turned out to have a quite different susceptibility towards fungal contamination. Whereas insulations made of bloated Perlite (plaster and board) did not show any fungal growth after 2 years of exposition, the historical insulation made of loam and weed had high cell counts of various fungi. In laboratory experiments wooden softboard represented the best environment for fungal growth. As a result from this study, plaster and board made of bloated Perlite are presented as being the most appropriate materials for thermal insulation at least from the microbiological and hygienic point of view. For future investigations and for the monitoring of fungi in insulation and other building materials we suggest a molecular biology approach with a common protocol for quantitative DNA-extraction and amplification.

  8. High-performance, non-CFC-based thermal insulation: Gas filled panels

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, B.T.; Arasteh, D.; Selkowitz, S.

    1992-04-01

    Because of the forthcoming phase-out of CFCs and to comply with the more stringent building and appliance energy-use standards, researchers in industry and in the public sector are pursuing the development of non-CFC-based, high-performance insulation materials. This report describes the results of research and development of one alternative insulation material: highly insulating GFPs. GFPs insulate in two ways: by using a gas barrier envelope to encapsulate a low-thermal-conductivity gas or gas mixture (at atmospheric pressure), and by using low-emissivity baffles to effectively eliminate convective and radiative heat transfer. This approach has been used successfully to produce superinsulated windows. Unlike foams or fibrous insulations, GFPs are not a homogeneous material but rather an assembly of specialized components. The wide range of potential applications of GFPs (appliances, manufactured housing, site-built buildings, refrigerated transport, and so on) leads to several alternative embodiments. While the materials used for prototype GFPs are commercially available, further development of components may be necessary for commercial products. With the exception of a description of the panels that were independently tested, specific information concerning panel designs and materials is omitted for patent reasons; this material is the subject of a patent application by Lawrence Berkeley Laboratory.

  9. Water vapor flow and high thermal resistance insulation systems for metal buildings

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, R.M.

    1983-01-01

    In response to increasing energy costs, high thermal resistance insulation systems are being marketed for pre-engineered metal buildings. Historically, blanket insulation has been installed between the skin and the structure of these buildings. The new insulation systems generally are installed inside the structure; thus the structure is colder and, unless an effective retarder is included, water vapor condensation problems can result. While the vapor permeance of various insulation facing materials is documented, the effect of such field conditions as seams and penetrations is less well known. Permeance tests were performed on samples of foil-kraft paper insulation facing with two seams and two penetration configurations. The tests show that seams can multiply the permeance of the vapor retarder by factors of 1.2 or more and penetrations can multiply the permeance by 3 or more. The theory of vapor flow analysis is reviewed and compared with the test results and presented graphically. Possible applications and suggestions for further investigation are discussed.

  10. Water vapor flow and high thermal resistance insulation systems for metal buildings

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, R.M.

    1981-12-01

    In response to increasing energy costs, high thermal resistance insulation systems are being marketed for pre-engineered metal buildings. Historically, blanket insulation has been installed between the skin and the structure of these buildings. The new insulation systems generally are installed inside the structure; thus the structure is colder and, unless an effective retarder is included, water vapor condensation problems can result. While the vapor permeance of various insulation facing materials is documented, the effect of such field conditions as seams and penetrations is less well known. Permeance tests were performed on samples of foil-kraft paper insulation facing with two seams and two penetration configurations. The tests show that seams can multiply the permeance of the vapor retarder by factors of 1.2 or more and penetrations can multiply the permeance by 3 or more. The theory of vapor flow analysis is reviewed and compared with the test results and presented graphically. Possible applications and suggestions for further investigation are discussed.

  11. Silicon Oxycarbide Aerogels for High-Temperature Thermal Insulation

    Science.gov (United States)

    Evans, Owen; Rhine, Wendell; Coutinho, Decio

    2010-01-01

    This work has shown that the use of SOC-A35 leads to aerogel materials containing a significant concentration of carbidic species and limited amorphous free carbon. Substitution of the divalent oxide species in silica with tetravalent carbidic carbon has directly led to materials that exhibit increased network viscosity, reduced sintering, and limited densification. The SiOC aerogels produced in this work have the highest carbide content of any dense or porous SiOC glass reported in the literature at that time, and exhibit tremendous long-term thermal stability.

  12. A comparison of methods for assessing the thermal insulation value of children's schoolwear in Kuwait.

    Science.gov (United States)

    Al-Rashidi, Khaled; Loveday, Dennis; Al-Mutawa, Nawaf; Havenith, George

    2012-01-01

    In this study, three methods were used to determine the thermal insulation values of different school clothing worn by 6 to 17 year old girls and boys in Kuwait classrooms for both summer and winter seasons. The different clothing ensembles' insulations were determined by 1: measurement using adult-sized versions of the clothing on thermal manikins, 2: estimations from adult clothing data obtained from the standards tables in ISO 9920 and ASHRAE 55, and 3: calculations using a regression equation from McCullough et al. (1985) that was adapted to accommodate children's sizes for ages 6-17 years. Values for the clothing area factor, f(cl), were also determined by measurement and by using a prediction equation from ISO 9920. Results in this study suggested that the clothing insulation values found from the measured and adapted data were similar to the adult's data in standards tables for the same summer and winter seasons. Further, the effect of the insulation values on the different scholars' age groups were investigated using the clothing temperature rating technique and compared to the scholars' comfort temperature found in recent field studies. Results showed that the temperature ratings of the clothing using the three methods described above are close and in agreement with the scholars' comfort temperature. Though estimated and measured f(cl) data differed, the impact on the temperature ratings was limited. An observed secular change in the children's heights and weights in the last few decades implies that, for adolescents, the children's body surface areas are similar to those of adults, making the use of adult clothing tables even more acceptable. In conclusion, this study gives some evidence to support the applicability of using adults' data in ASHRAE 55 and ISO 9920 standards to assess the thermal insulation values of different children's clothing ensembles, provided that careful selection of the garments, ensembles material and design takes place. Copyright

  13. Thermal Performance Testing of Cryogenic Multilayer Insulation with Silk Net Spacers

    Science.gov (United States)

    Johnson, W. L.; Frank, D. J.; Nast, T. C.; Fesmire, J. E.

    2015-12-01

    Early comprehensive testing of cryogenic multilayer insulation focused on the use of silk netting as a spacer material. Silk netting was used for multiple test campaigns that were designed to provide baseline thermal performance estimates for cryogenic insulation systems. As more focus was put on larger systems, the cost of silk netting became a deterrent and most aerospace insulation firms were using Dacron (or polyester) netting spacers by the early 1970s. In the midst of the switch away from silk netting there was no attempt to understand the difference between silk and polyester netting, though it was widely believed that the silk netting provided slightly better performance. Without any better reference for thermal performance data, the silk netting performance correlations continued to be used. In order to attempt to quantify the difference between the silk netting and polyester netting, a brief test program was developed. The silk netting material was obtained from Lockheed Martin and was tested on the Cryostat-100 instrument in three different configurations, 20 layers with both single and double netting and 10 layers with single netting only. The data show agreement within 15 - 30% with the historical silk netting based correlations and show a substantial performance improvement when compared to previous testing performed using polyester netting and aluminum foil/fiberglass paper multilayer insulation. Additionally, the data further reinforce a recently observed trend that the heat flux is not directly proportional to the number of layers installed on a system.

  14. The empirical evaluation of thermal conduction coefficient of some liquid composite heat insulating materials

    Science.gov (United States)

    Anisimov, M. V.; Rekunov, V. S.; Babuta, M. N.; Bach Lien, Nguyen Thi Hong

    2016-02-01

    We experimentally determined the coefficients of thermal conductivity of some ultra thin liquid composite heat insulating coatings, for sample #1 λ = 0.086 W/(m·°C), for sample #2 λ = 0.091 W/(m·°C). We performed the measurement error calculation. The actual thermal conduction coefficient of the studied samples was higher than the declared one. The manufactures of liquid coatings might have used some "ideal" conditions when defining heat conductivity in the laboratory or the coefficient was obtained by means of theoretical solution of heat conduction problem in liquid composite insulating media. However, liquid insulating coatings are of great interest to builders, because they allow to warm objects of complex geometric shapes (valve chambers, complex assemblies, etc.), which makes them virtually irreplaceable. The proper accounting of heating qualities of paints will allow to avoid heat loss increase above the specified limits in insulated pipes with heat transfer materials or building structures, as well as protect them from possible thawing in the period of subzero weather.

  15. The empirical definition of total emissivity of modern superthin liquid composite thermal insulators

    Science.gov (United States)

    Anisimov, M. V.; Rekunov, V. S.; Babuta, M. N.; Lychagin, D. V.; Kuznetsova, U. N.; Bach Lien, Nguyen Thi Hong; Ivanova, E. V.; Taalaybekov, Z. T.

    2016-11-01

    Modern world trends in the field of energy and mineral resources preservation policy involves the need for a more cost-efficient use of the Earth's natural resources, including in the field of construction industry. Using insulation modern materials would largely solve this problem. The acceptability appraisal of various advanced heat-insulating blankets is a crucial task, which requires experimental verification of total emissivity empirical definition of modern super-thin liquid composite thermal insulators and their real value definition. Method of investigation is as follows: an empirical definition of blankets emissivity using the proposed laboratory equipment, which comprises a system of "gray" bodies, thermocouple probe and a source of continuous heat flux. Total emissivity of modern super-thin liquid composite thermal insulators is experimentally determined. It amounted e = 0.89 for sample # 1, and e = 0.87 for sample # 2 at a temperature of 35-65 °C. It was found that the actual emissivity of the samples was higher than it had been declared.

  16. Photoacoustic emission from Au nanoparticles arrayed on thermal insulation layer.

    Science.gov (United States)

    Namura, Kyoko; Suzuki, Motofumi; Nakajima, Kaoru; Kimura, Kenji

    2013-04-08

    Efficient photoacoustic emission from Au nanoparticles on a porous SiO(2) layer was investigated experimentally and theoretically. The Au nanoparticle arrays/porous SiO(2)/SiO(2)/Ag mirror sandwiches, namely, local plasmon resonators, were prepared by dynamic oblique deposition (DOD). Photoacoustic measurements were performed on the local plasmon resonators, whose optical absorption was varied from 0.03 (3%) to 0.95 by varying the thickness of the dielectric SiO(2) layer. The sample with high absorption (0.95) emitted a sound that was eight times stronger than that emitted by graphite (0.94) and three times stronger than that emitted by the sample without the porous SiO(2) layer (0.93). The contribution of the porous SiO(2) layer to the efficient photoacoustic emission was analyzed by means of a numerical method based on a one-dimensional heat transfer model. The result suggested that the low thermal conductivity of the underlying porous layer reduces the amount of heat escaping from the substrate and contributes to the efficient photoacoustic emission from Au nanoparticle arrays. Because both the thermal conductivity and the spatial distribution of the heat generation can be controlled by DOD, the local plasmon resonators produced by DOD are suitable for the spatio-temporal modulation of the local temperature.

  17. Thermal and electrical properties of thermal-grease-insulated REBCO superconducting coils with respect to winding tension

    Science.gov (United States)

    Song, Jung-Bin; Choi, Yoon Hyuck; Yang, Dong Gyu; Kim, Young-Gyun; Kim, Seong-Gyeom; Choi, Yeon Suk; Lee, Haigun

    2017-09-01

    This study investigates the thermal and electrical characteristics of a silicon-based grease insulation (GI) GdBCO coil with respect to the winding tension through charge, sudden discharge, and over-current tests. Charge and sudden discharge test results demonstrate that the charging/discharging delay time increases as the winding tension increases; this is because the characteristic resistance of the coil decreases due to the reduced contact resistance. The over-current test results confirm that the thermal/electrical stabilities of the GI coil are considerably enhanced with an increased winding tension resulting from improved thermal contact and the decrease in the electrical contact resistance between the turn-to-turn layers of the coil. Thus, as the winding tension increases, the charging/discharging rates decrease whereas the thermal/electrical stabilities improve. Overall, selecting the appropriate winding tension for a GI coil is critical for achieving thermal/electrical stabilities, as well as ameliorating the charging/discharging delay phenomenon generally observed in a no-insulation coil.

  18. Influence of Textile Structure and Silica Based Finishing on Thermal Insulation Properties of Cotton Fabrics

    Directory of Open Access Journals (Sweden)

    G. Rosace

    2016-01-01

    Full Text Available The aim of this work is to investigate the influence of weave structures and silica coatings obtained via sol-gel process on the thermal insulation properties of cotton samples. For this reason three main weave structures (plain, satin, and piqué of cotton fabric were selected with different yarn count, threads per cm, and mass per square meter values. Thereafter, only for the plain weave, the samples were padded using silica sol formed by hydrolysis and subsequent condensation of 3-glycidoxypropyltrimethoxysilane under acidic conditions. The silanized plain weave samples were characterized by TGA and FT-IR techniques. The thermal properties were measured with a home-made apparatus in order to calculate thermal conductivity, resistance, and absorption of all the treated fabric samples. The relationship between the thermal insulation properties of the plain weave fabrics and the concentration of sol solutions has been investigated. Fabrics weave and density were found to strongly influence the thermal properties: piqué always shows the lowest values and satin shows the highest values while plain weave lies in between. The thermal properties of treated high-density cotton plain weave fabric were proved to be strongly influenced by finishing agent concentration.

  19. Flyweight 3D Graphene Scaffolds with Microinterface Barrier-Derived Tunable Thermal Insulation and Flame Retardancy.

    Science.gov (United States)

    Zhang, Qiangqiang; Hao, Menglong; Xu, Xiang; Xiong, Guoping; Li, Hui; Fisher, Timothy S

    2017-04-26

    In this article, flyweight three-dimensional (3D) graphene scaffolds (GSs) have been demonstrated with a microinterface barrier-derived thermal insulation and flame retardancy characteristics. Such 3D GSs were fabricated by a modified hydrothermal method and a unidirectional freeze-casting process with hierarchical porous microstructures. Because of high porosity (99.9%), significant phonon scattering, and strong π-π interaction at the interface barriers of multilayer graphene cellular walls, the GSs demonstrate a sequence of multifunctional properties simultaneously, such as lightweight density, thermal insulating characteristics, and outstanding mechanical robustness. At 100 °C, oxidized GSs exhibit a thermal conductivity of 0.0126 ± 0.0010 W/(m K) in vacuum. The thermal conductivity of oxidized GSs remains relatively unaffected despite large-scale deformation-induced densification of the microstructures, as compared to the behavior of reduced GSs (rGSs) whose thermal conductivity increases dramatically under compression. The contrasting behavior of oxidized GSs and rGSs appears to derive from large differences in the intersheet contact resistance and varying intrinsic thermal conductivity between reduced and oxidized graphene sheets. The oxidized GSs also exhibit excellent flame retardant behavior and mechanical robustness, with only 2% strength decay after flame treatment. In a broader context, this work demonstrates a useful strategy to design porous nanomaterials with a tunable heat conduction behavior through interface engineering at the nanoscale.

  20. Cryogenic Thermal Performance Testing of Bulk-Fill and Aerogel Insulation Materials

    Science.gov (United States)

    Scholtens, B. E.; Fesmire, J. E.; Sass, J. P.; Augustynowicz, S. D.; Heckle, K. W.

    2007-01-01

    The research testing and demonstration of new bulk-fill materials for cryogenic thermal insulation systems was performed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. Thermal conductivity testing under actual-use cryogenic conditions is a key to understanding the total system performance encompassing engineering, economics, and materials factors. A number of bulk fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, were tested using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boil-off method were 293 K and 78 K. Tests were performed as a function of cold vacuum pressure from high vacuum to no vacuum conditions. Results are compared with other complementary test methods in the range of 300 K to 20 K. Various testing techniques are shown to be required to obtain a complete understanding of the operating performance of a material and to provide data for answers to design engineering questions.

  1. Potential of Hollow Glass Microsphere as Cement Replacement for Lightweight Foam Concrete on Thermal Insulation Performance

    Directory of Open Access Journals (Sweden)

    Shahidan Shahiron

    2017-01-01

    Full Text Available Global warming can be defined as a gradual increase in the overall temperature of the earth’s atmosphere. A lot of research work has been carried out to reduce that heat inside the residence such as the used of low density products which can reduce the self-weight, foundation size and construction costs. Foamed concrete it possesses high flow ability, low self-weight, minimal consumption of aggregate, controlled low strength and excellent thermal insulation properties. This study investigate the characteristics of lightweight foamed concrete where Portland cement (OPC was replaced by hollow glass microsphere (HGMs at 0%, 3%, 6%, 9% by weight. The density of wet concrete is 1000 kg/m3 were tested with a ratio of 0.55 for all water binder mixture. Lightweight foamed concrete hollow glass microsphere (HGMs produced were cured by air curing and water curing in tank for 7, 14 and 28 days. A total of 52 concrete cubes of size 100mm × 100mm × 100mm and 215mm × 102.5mm × 65mm were produced. Furthermore, Scanning Electron Microscope (SEM and X-ray fluorescence (XRF were carried out to study the chemical composition and physical properties of crystalline materials in hollow glass microspheres. The experiments involved in this study are compression strength, water absorption test, density and thermal insulation test. The results show that the compressive strength of foamed concrete has reached the highest in 3% of hollow glass microsphere with less water absorption and less of thermal insulation. As a conclusion, the quantity of hollow glass microsphere plays an important role in determining the strength and water absorption and also thermal insulation in foamed concrete and 3% hollow glass microspheres as a replacement for Portland cement (OPC showed an optimum value in this study as it presents a significant effect than other percentage.

  2. Vacuum insulation - Panel properties and building applications. HiPTI - High Performance Thermal Insulation - IEA/ECBCS Annex 39 - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Erb, M. (ed.)

    2005-12-15

    This paper takes a look at the properties of vacuum insulation panels (VIP) that have already been developed some time ago for use in appliances such as refrigerators and deep-freezers. Their insulation performance is a factor of five to ten times better than that of conventional insulation. The paper discusses the use of such panels in buildings to provide thin, highly-insulating constructions for walls, roofs and floors. The motivation for examining the applicability of high performance thermal insulation in buildings is discussed, including solutions where severe space limitations and other technical and aesthetic considerations exist. The use of nano-structured materials and laminated foils is examined and discussed. The questions arising from the use of such panels in buildings is discussed and the open questions and risks involved are examined. Finally, an outlook on the introduction of VIP technology is presented and quality assurance aspects are examined. This work was done within the framework of the Task 39 'High Performance Thermal Insulation' of the 'Energy Conservation in Buildings and Community Systems ECBCS' programme of the International Energy Agency IEA.

  3. Needle-Bonded Electromagnetic Shielding Thermally Insulating Nonwoven Composite Boards: Property Evaluations

    Directory of Open Access Journals (Sweden)

    Jia-Horng Lin

    2016-10-01

    Full Text Available Complicated environmental problems inevitably arise when technology advances. One major environmental problem is the presence of electromagnetic radiation. Long-term exposure to electromagnetic radiation can damage people’s health in many ways. Therefore, this study proposes producing composite boards with electromagnetic shielding effectiveness and thermal insulation by utilizing the structures and properties of materials. Different combinations of flame-retardant polyester fiber (FR fiber, recycled far-infrared polyester fiber (FI fiber, and 4D low-melting-point fibers (LM fiber were made into flame-retardant and thermally insulating matrices. The matrices and carbon fiber (CF woven fabric in a sandwich-structure were needle-punched in order to be tightly compact, and then circularly heat dried in order to have a heat set and reinforced structure. The test results indicate that Polyester (PET/CF composite boards are mechanically strong and have thermal insulation and electromagnetic shielding effectiveness at a frequency between 0.6 MHz and 3 GHz.

  4. EVALUATION OF THERMAL INSULATION FOR THREE DIFFERENT MATERIALS USED IN CONSTRUCTION AND COMPLETION OF EXTERNAL WALLS

    Directory of Open Access Journals (Sweden)

    Marcio Carlos Navroski

    2010-05-01

    Full Text Available Summers increasingly hot are bringing large thermal problems within homes and businesses, leading to increased demand for installation of air conditioners and the consequent high energy consumption. Constructions with thermal insulation on its external walls thatcould reduce energy use or even supply the use of such equipment. Due to these factors the present study was to evaluate the insulation in three boxes built with different materials, one made of wooden boards with plain walls, and two built with plywood, wall insulation andinterior walls filled with rice husk and Styrofoam®. The boxes were built after placed in drying oven at 40 °C, then noted the temperature inside the same interval every five minutes using a digital thermometer. The box with inner Styrofoam® showed the lowest variation among the three evaluated, followed by the box of rice husk. These two materials also showed good thermal initial, unlike the box built only with wood, which showed a large interiorheating, lay in a drying oven.

  5. Surface Thermal Insulation and Pipe Cooling of Spillways during Concrete Construction Period

    Directory of Open Access Journals (Sweden)

    Wang Zhenhong

    2014-01-01

    Full Text Available Given that spillways adopt a hydraulic thin concrete plate structure, this structure is difficult to protect from cracks. The mechanism of the cracks in spillways shows that temperature stress is the major reason for cracks. Therefore, an effective way of preventing cracks is a timely and reasonable temperature-control program. Studies show that one effective prevention method is surface thermal insulation combined with internal pipe cooling. The major factors influencing temperature control effects are the time of performing thermal insulation and the ways of internal pipe cooling. To solve this problem, a spillway is taken as an example and a three-dimensional finite element program and pipe cooling calculation method are adopted to conduct simulation calculation and analysis on the temperature fields and stress fields of concretes subject to different temperature-control programs. The temperature-control effects are then compared. Optimization results show that timely and reasonable surface thermal insulation and water-flowing mode can ensure good temperature-control and anticrack effects. The method has reference value for similar projects.

  6. Rational use of energy by thermal insulation of residential buildings. Rationelle Energienutzung durch Waermeschutz von Wohngebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Feist, W. (Inst. Wohnen und Umwelt, Darmstadt (Germany))

    1992-01-01

    Processes in buildings need to be studied in detail to determine the technical potential of energy savings. Simulation models for thermal behaviour and simulation calculations prove that the technologies available today and the building input justifiable for the central-European climate will allow so-called passive-systems buildings to be built. Such a passive-systems building was built in Darmstadt Kranichstein. The heart of these passive-systems buildings is an excellent thermal insulation, its meticulous execution and the reduction of heat losses by ventilation. (BWI)

  7. Reduction in the thermal resistance (R-value) of loose-fill insulation and fiberglass batts due to compression

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, D.W.; Wright, J.H.

    1981-04-01

    A method is presented for calculating the thickness reduction of loose-fill insulations and fiberglass batts that result from compressive forces exerted by additional insulation. The thickness reduction is accompanied by an increase in density and a reduction in the R value of the compressed layer. Calculations for thermal resistance of two layers of insulation are given. Information in 4 appendices includes: identification of products tested (products from 3 companies); experimental values for thickness as a function of loading; Fortran programs and output; and calculated R values for stacked insulations. (MCW)

  8. Quick quality inspection of thermal parameters of heat-insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Stanislaw, C.; Waldemar, M. [Technical Univ. of Czestochowa (Poland). Div. of Microprocessor Systems, Automatic Control and Heat Measurements

    2001-07-01

    Methods used in practice to determine thermal parameters of materials are based mainly on stationary heat transfer conditions or are applied to regular conditions of nonstationary heat transfer. In the case of determining thermal parameters of thick heat-insulating plates, the time period required to obtain regular conditions of heat transfer is relatively long. Therefore, it is proposed to measure the thermal parameters from an instant at which a thermal input is applied to the body edge. For the sake of implementation simplicity and better modeling possibilities of considered phenomena, we decided to employ several numerical algorithms that are presented in the paper. Because a one-dimensional model of the heat conduction is assumed, it is necessary to consider a sample, whose thickness is many times smaller than its lateral dimensions as well as lateral dimensions of the heater plate. The dynamic method presented in the work together with the portable measuring system, is intended for fast (1-2 minutes) determining thermal parameters of heat-insulating materials used in the building engineering and industry, like e.g. foamed polystyrene or mineral wool. A portable measuring system could control online the quality of materials at the production line output in terms of their thermophysical parameters. (orig.)

  9. THERMAL INSULATION PROPERTIES RESEARCH OF THE COMPOSITE MATERIAL WATER GLASS–GRAPHITE MICROPARTICLES

    Directory of Open Access Journals (Sweden)

    V. A. Gostev

    2014-05-01

    Full Text Available Research results for the composite material (CM water glass–graphite microparticles with high thermal stability and thermal insulation properties are given. A composition consisting of graphite (42 % by weight, water glass Na2O(SiO2n (50% by weight and the hardener - sodium silicofluoric Na2SiF6 (8% by weight. Technology of such composition receipt is suggested. Experimental samples of the CM with filler particles (graphite and a few microns in size were obtained. This is confirmed by a study of samples by X-ray diffraction and electron microscopy. The qualitative and quantitative phase analysis of the CM structure is done. Load limit values leading to the destruction of CM are identified. The character of the rupture surface is detected. Numerical values of specific heat and thermal conductivity are defined. Dependence of the specific heat capacity and thermal conductivity on temperature at monotonic heating is obtained experimentally. Studies have confirmed the increased thermal insulation properties of the proposed composition. CM with such characteristics can be recommended as a coating designed to reduce heat losses and resistant to high temperatures. Due to accessibility and low cost of its components the proposed material can be produced on an industrial scale.

  10. Measurements of clothing insulation with a thermal manikin operating under the thermal comfort regulation mode: comparative analysis of the calculation methods.

    Science.gov (United States)

    Oliveira, A Virgílio M; Gaspar, Adélio R; Quintela, Divo A

    2008-11-01

    The present work is dedicated to a comparative analysis of calculation methods about clothing insulation with a thermal manikin operating under the thermal comfort regulation mode. The serial, global, and parallel calculation methods are considered and the thermal insulation results for garments (30) and ensembles (9) are discussed. The serial and parallel methods presents the higher and lower values, respectively, and the differences were sometimes significant. Considering the results for the effective thermal insulation, the mean values of the relative differences between the serial and global methods were 25.7% for the daily wear garments, 45.2% for the cold protective garments and 38.5% for the ensembles. The corresponding mean values for the global and parallel methods were 8.7, 15.8, and 10.5%, respectively. Since any uneven clothing insulation is to be expected as a source of error, particular care must be required when the calculation methods deal with cold protective clothing.

  11. Evaluation of mechanical and thermal properties of insulation materials for HTS power devices at liquid nitrogen temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hyung Seop; Diaz, Mark Angelo [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of)

    2017-06-15

    In superconducting power devices including power cables in which high temperature superconducting (HTS) tapes are utilized, a reliable electrical insulation should be achieved for its maximum performance. For an efficient design of HTS superconducting devices, a comparative evaluation of the mechanical and thermal propperties for various insulation materials at cryogenic temperatures is required. Especially, in the process of the property evaluation of the sheet-shaped insulation materials, anisotropy according to the machining direction should be considered because the mechanical and thermal properties are significantly influenced by the sample orientation. In this study, the cryogenic thermal and mechanical properties of various insulation material sheets such as PPLP, Cryoflex, Teflon, and Kapton were determined considering sample orientation. All samples tested at cryogenic temperature showed significantly higher tensile strength as compared with that of room temperature. The ultimate tensile strength at both temperature conditions significantly depended upon the sample orientation. The thermal properties of the insulation materials exhibited a slight difference among samples depending on the orientation: for the PPLP and Cryoflex, the CD orientation showed larger thermal contraction up to 77 K as compared to the MD one. MD samples in PPLP and Cryoflex showed a lower CTE and thermal contraction which made it more promising as an insulation material due to its comparable CTE with HTS CC tapes.

  12. High temperature properties of ceramic fibers and insulations for thermal protection of atmospheric entry and hypersonic cruise vehicles

    Science.gov (United States)

    Kourtides, Demetrius A.; Pitts, William C.; Araujo, Myrian; Zimmerman, R. S.

    1988-01-01

    Multilayer insulations (MIs) which will operate in the 500 to 1000 C temperature range are being considered for possible applications on aerospace vehicles subject to convective and radiative heating during atmospheric entry. The insulations described consist of ceramic fibers, insulations, and metal foils quilted together with ceramic thread. As these types of insulations have highly anisotropic properties, the total heat transfer characteristics must be determined. Data are presented on the thermal diffusivity and thermal conductivity of four types of MIs and are compared to the baseline Advanced Flexible Reusable Surface Insulation currently used on the Space Shuttle Orbiter. In addition, the high temperature properties of the fibers used in these MIs are discussed. The fibers investigated included silica and three types of aluminoborosilicate (ABS). Static tension tests were performed at temperatures up to 1200 C and the ultimate strain, tensile strength, and tensile modulus of single fibers were determined.

  13. Linear thermal bridges in vacuum insulated constructions.; Lineare Waermebruecken in vakuumgedaemmten Konstruktionen

    Energy Technology Data Exchange (ETDEWEB)

    Willems, Wolfgang; Skottke, Tanja [Technische Universitaet Dortmund, Fakultaet Bauwesen, Lehrstuhl fuer Bauphysik und Technische Gebaeudeausruestung, Dortmund (Germany)

    2008-12-15

    Continuously rising demands on the structural thermal insulation of heated buildings lead under certain conditions to high efficient insulation materials, which achieve its efficiency by using the vacuum technology. Inside these elements there is a medium vacuum that has to be durable to guarantee the excellent heat insulating characteristic. For that purpose a non-permeable enveloping of the core material is essential, which breeds around the element edges increased heat losses, especially referring to the element joints concerning large vacuum insulated areas. This paper quantifies these additional heat losses for different constructions based on measurements. (Abstract Copyright [2008], Wiley Periodicals, Inc.) [German] Die konsequent ansteigenden Anforderungen an den baulichen Waermeschutz beheizter Gebaeude fuehren unter bestimmten Randbedingungen zum Einsatz hochleistungsfaehiger Waermedaemmelemente, deren Leistungsfaehigkeit auf dem Einsatz der Vakuumtechnologie basiert. Das in den Elementen erzeugte Feinvakuum muss dauerhaft erhalten bleiben, um die exzellenten Waermedaemmeigenschaften gewaehrleisten zu koennen. Die dazu erforderliche permeationsdichte Einhuellung des Stuetzkernmaterials fuehrt naturgemaess im Bereich der Elementkanten - und hier besonders im Bereich der bei groesseren gedaemmten Flaechen erforderlichen Elementstoesse - zu erhoehten Waermeverlusten. Die vorliegende Arbeit quantifiziert diese zusaetzlichen Waermeverluste fuer unterschiedliche Konstruktionen auf der Basis von Messungen. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  14. Thermally conductive and electrically insulating EVA composite encapsulant for solar photovoltaic (PV cell

    Directory of Open Access Journals (Sweden)

    2008-05-01

    Full Text Available A new way of improving the heat dissipating ability and PV efficiency of the solar cells by enhancing the thermal conductivity of the rear EVA layer was reported. The thermal conductivity, electrical resistivity, degree of curing of the EVA encapsulating composites and the PV efficiency of the solar cells are investigated. Filling with the thermal conductive fillers enhances the thermal conductivity of the composites effectively. The thermal conductivity of the filler influences significantly the thermal conductivity of the composite at high filler loading (greater than 20 vol%. Thermal conductivities of the composites filled with SiC, ZnO or BN reach respectively 2.85, 2.26 and 2.08 W/m•K at filler content of 60 vol%. The composites filled with ZnO or BN exhibit superior electrical insulation to those filled with SiC or Al2O3. ZnO can promote the cross-linking reaction of the EVA matrix. The test results indicated that the EVA composite encapsulating rear films filled with thermal conductive fillers are able to improve the PV efficiency and the heat dissipating ability of the solar cell effectively.

  15. Acoustic and Thermal Testing of an Integrated Multilayer Insulation and Broad Area Cooling Shield System

    Science.gov (United States)

    Wood, Jessica J.; Foster, Lee W.

    2013-01-01

    A Multilayer Insulation (MLI) and Broad Area Cooling (BAC) shield thermal control system shows promise for long-duration storage of cryogenic propellant. The NASA Cryogenic Propellant Storage and Transfer (CPST) project is investigating the thermal and structural performance of this tank-applied integrated system. The MLI/BAC Shield Acoustic and Thermal Test was performed to evaluate the MLI/BAC shield's structural performance by subjecting it to worst-case launch acoustic loads. Identical thermal tests using Liquid Nitrogen (LN2) were performed before and after the acoustic test. The data from these tests was compared to determine if any degradation occurred in the thermal performance of the system as a result of exposure to the acoustic loads. The thermal test series consisted of two primary components: a passive boil-off test to evaluate the MLI performance and an active cooling test to evaluate the integrated MLI/BAC shield system with chilled vapor circulating through the BAC shield tubes. The acoustic test used loads closely matching the worst-case envelope of all launch vehicles currently under consideration for CPST. Acoustic test results yielded reasonable responses for the given load. The thermal test matrix was completed prior to the acoustic test and successfully repeated after the acoustic test. Data was compared and yielded near identical results, indicating that the MLI/BAC shield configuration tested in this series is an option for structurally implementing this thermal control system concept.

  16. A lime based mortar for thermal insulation of medieval church vaults

    DEFF Research Database (Denmark)

    Hansen, Tessa Kvist; Larsen, Poul Klenz; Hansen, Kurt Kielsgaard

    was measured to 0.08 W/mK, which is twice the value for mineral wool. It has 1/3 of the resistance to water vapour diffusion as brick, and a high capacity for liquid water absorption. This is a benefit in the case of rain leaking from the roof, because the water does not penetrate further down into the bricks.......There are 1700 medieval churches in Denmark, and many of these have brick vaults. The thickness is only 12 – 15 cm, and the heat loss through this building component is large. Thermal insulation has not been permitted until now in respect for the antiquarian values and doubts about the effect...... on water vapour transport through the vault, and the risk of condensation inside the insulation. A new mortar was developed for thermal insulation of bricks vaults, consisting mainly of expanded perlite, mixed with slaked lime. These materials are compatible with the fired clay bricks and the lime mortar...

  17. Comparative Analysis of the Thermal Insulation of Traditional and Newly Designed Protective Clothing for Foundry Workers

    Directory of Open Access Journals (Sweden)

    Iwona Frydrych

    2016-09-01

    Full Text Available An objective of the undertaken research was checking the applicability of aluminized basalt fabrics for the production of clothing for foundry workers. The results of flammability, the resistance to contact, convective and radiation heat, as well as the resistance to big molten metal splashes confirmed the thesis of applicability of the packages with the use of aluminized basalt fabric content for the assumed purpose; therefore, such protective clothing was produced. Thermal comfort of foundry workers is very important and related to many factors, i.e., the structure of the protective clothing package, the number of layers, their thickness, the distance between the body and appropriate underwear. In the paper, a comparison of the results of thermal insulation measurement of two kinds of protective clothing is presented: the traditional one made of aluminized glass fabrics and the new one made of aluminized basalt fabrics. Measurements of clothing thermal insulation were conducted using a thermal manikin dressed in the protective clothing and three kinds of underwear products covering the upper and lower part of the manikin.

  18. Experimental study on manufacturing of insulation vacuum glazing and measurement of the thermal conductance

    Energy Technology Data Exchange (ETDEWEB)

    Song, Tae Ho; Yoon, Il Seob [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kwak, Ho Sang [Kumoh National Institute of Technology, Gumi (Korea, Republic of); Lee, Bo Hwa [Korea Aerospace Research Institute, Daejeon (Korea, Republic of)

    2006-08-15

    Window is a critical component in the design of energy-efficient buildings. To minimize the heat loss, insulation performance of the glazing has to be improved. Manufacturing of vacuum glazing has been motivated by the possibility of making windows of very good thermal insulation properties for such applications. It is made by maintaining vacuum in the gap between two glass panes. Pillars are placed between them to withstand the atmospheric pressure. Edge covers are applied to reduce conduction through the edge. Accurate measurements have been made of the radiative heat transfer, the pillar conduction and the gas conduction using a guarded hot plate apparatus. Vacuum glazing is found to have low thermal conductance roughly below 1W/m{sup 2}K. Among the heat transfer modes of residual gas conduction, conduction through support pillar and the radiative heat transfer between the glass panes, the last one is the most dominant to the overall thermal conductance. Vacuum glazing using very low emittance Al-coated glass has an overall thermal conductance of about 0.7W/m{sup 2}K.

  19. Thermal conductivity of aerogel blanket insulation under cryogenic-vacuum conditions in different gas environments

    Science.gov (United States)

    E Fesmire, J.; Ancipink, J. B.; Swanger, A. M.; White, S.; Yarbrough, D.

    2017-12-01

    Thermal conductivity of low-density materials in thermal insulation systems varies dramatically with the environment: cold vacuum pressure, residual gas composition, and boundary temperatures. Using a reference material of aerogel composite blanket (reinforcement fibers surrounded by silica aerogel), an experimental basis for the physical heat transmission model of aerogel composites and other low-density, porous materials is suggested. Cryogenic-vacuum testing between the boundary temperatures of 78 K and 293 K is performed using a one meter cylindrical, absolute heat flow calorimeter with an aerogel blanket specimen exposed to different gas environments of nitrogen, helium, argon, or CO2. Cold vacuum pressures include the full range from 1×10-5 torr to 760 torr. The soft vacuum region, from about 0.1 torr to 10 torr, is complex and difficult to model because all modes of heat transfer – solid conduction, radiation, gas conduction, and convection – are significant contributors to the total heat flow. Therefore, the soft vacuum tests are emphasized for both heat transfer analysis and practical thermal data. Results for the aerogel composite blanket are analyzed and compared to data for its component materials. With the new thermal conductivity data, future applications of aerogel-based insulation systems are also surveyed. These include Mars exploration and surface systems in the 5 torr CO2 environment, field joints for vacuum-jacketed cryogenic piping systems, common bulkhead panels for cryogenic tanks on space launch vehicles, and liquid hydrogen cryofuel systems with helium purged conduits or enclosures.

  20. Influence of gamma ray irradiation on thermal conductivity of bismaleimide-triazine-based insulation tape at cryogenic temperature

    Science.gov (United States)

    Yang, Y.; Yoshida, M.; Idesaki, A.; Ogitsu, T.

    2018-01-01

    Recent accelerator-based experiments for particle physics require the superconducting magnets that can be operated under high radiation environment. An electrical insulation tape, which is composed of polyimide film and a boron free glass fabric pre-impregnated with epoxy resin blended with bismaleimide-triazine resin, is developed to enhance the radiation tolerance for superconducting magnets. Since the thermal conductivity of insulation tape is one of key parameters that affects the coil temperature during the operation, the influence of gamma-ray irradiation on the thermal conductivity of the insulation tape is investigated with a maximum dose of 5 MGy. The thermal conductivity is measured at cryogenic temperature from 5 K to 20 K cooled by a Gifford-McMahon cryocooler. By comparing the thermal conductivity before and after the gamma ray irradiation, no significant degradation on the thermal conductivity has been observed.

  1. Influence of Fuzzy Parameters on the Modeling Quality of XLPE Insulation Properties under Thermal Aging

    Directory of Open Access Journals (Sweden)

    Lakhdar Bessissa

    2016-03-01

    Full Text Available In this work, we have used the fuzzy logic approach to predict mechanical properties (hot set test of cross-linked polyethylene (XLPE used as insulation in high voltage cables. The studied property presents non linear variations according to the aging time under high temperatures. So it is very difficult to find a theoretical or experimental model of the properties evolution under thermal aging. For that reason, several factors have been considered such as aging time and applied temperature. The obtained results are very encouraging and pointed out that the fuzzy logic is a powerful tool to predict the insulation proprieties. In other words, the obtained results are in good accordance with the experimental results with an acceptable error margin.

  2. Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability.

    Science.gov (United States)

    Bröde, Peter; Kuklane, Kalev; Candas, Victor; Den Hartog, Emiel A; Griefahn, Barbara; Holmér, Ingvar; Meinander, Harriet; Nocker, Wolfgang; Richards, Mark; Havenith, George

    2010-01-01

    The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments' material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments.

  3. Polymethylsilsesquioxane-cellulose nanofiber biocomposite aerogels with high thermal insulation, bendability, and superhydrophobicity.

    Science.gov (United States)

    Hayase, Gen; Kanamori, Kazuyoshi; Abe, Kentaro; Yano, Hiroyuki; Maeno, Ayaka; Kaji, Hironori; Nakanishi, Kazuki

    2014-06-25

    Polymethylsilsesquioxane-cellulose nanofiber (PMSQ-CNF) composite aerogels have been prepared through sol-gel in a solvent containing a small amount of CNFs as suspension. Since these composite aerogels do not show excessive aggregation of PMSQ and CNF, the original PMSQ networks are not disturbed. Composite aerogels with low density (0.020 g cm(-3) at lowest), low thermal conductivity (15 mW m(-1) K(-1)), visible light translucency, bending flexibility, and superhydrophobicity thus have been successfully obtained. In particular, the lowest density and bending flexibility have been achieved with the aid of the physical supporting effect of CNFs, and the lowest thermal conductivity is comparable with the original PMSQ aerogels and standard silica aerogels. The PMSQ-CNF composite aerogels would be a candidate to practical high-performance thermal insulating materials.

  4. Numerical Calculation of Transient Thermal Characteristics in Gas-Insulated Transmission Lines

    Directory of Open Access Journals (Sweden)

    Hongtao Li

    2013-11-01

    Full Text Available For further knowledge of the thermal characteristics in gas-insulated transmission lines (GILs installed above ground, a finite-element model coupling fluid field and thermal field is established, in which the corresponding assumptions and boundary conditions are given.  Transient temperature rise processes of the GIL under the conditions of variable ambient temperature, wind velocity and solar radiation are respectively investigated. Equivalent surface convective heat transfer coefficient and heat flux boundary conditions are updated in the analysis process. Unlike the traditional finite element methods (FEM, the variability of the thermal properties with temperature is considered. The calculation results are validated by the tests results reported in the literature. The conclusion provides method and theory basis for the knowledge of transient temperature rise characteristics of GILs in open environment.

  5. Efficient Thermal Insulation of Passive House with Curved Façades in Cold Climate

    Directory of Open Access Journals (Sweden)

    Aznabaev Askar

    2016-01-01

    Full Text Available In this paper there is exploration of the possibility of creating effective sealed building envelope in zero energy building (ZEB with unique façades. This article describes passive and active measures of decrease of thermal loss through enclosure structures, usage of modern insulation materials; positive effect of rationalization of the façade orientation and form of a building in a plan; on the base of existing architecture concept structural solutions of building envelope are suggested. Using thermal FEA the enclosure structure was optimized. The results of modeling of units and elements of building envelope are: heat transfer coefficient U-value for heterogeneous multilayer structure, picture of temperature distribution and magnitude of the thermal conductivity and temperature of internal wall surface.

  6. Measurement of the thermal conductivity of thin insulating anisotropic material with a stationary hot strip method

    Science.gov (United States)

    Jannot, Yves; Degiovanni, Alain; Félix, Vincent; Bal, Harouna

    2011-03-01

    This paper presents a method dedicated to the thermal conductivity measurement of thin insulating anisotropic materials. The method is based on three hot-strip-type experiments in which the stationary temperature is measured at the center of the hot strip. A 3D model of the heat transfer in the system is established and simulated to determine the validity of a 2D transfer hypothesis at the center of the hot strip. A simplified 2D model is then developed leading to the definition of a geometrical factor calculable from a polynomial expression. A very simple calculation method enabling the estimation of the directional thermal conductivities from the three stationary temperature measurements and from the geometrical factor is presented. The uncertainties on each conductivity are estimated. The method is then validated by measurements on polyethylene foam and Ayous (anistropic low-density tropical wood); the estimated values of the thermal conductivities are in good agreement with the values estimated using the hot plate and the flash method. The method is finally applied on a thin super-insulating fibrous material for which no other method is able to measure the in-plane conductivity.

  7. Estimation of the thermal conductivity of hemp based insulation material from 3D tomographic images

    Science.gov (United States)

    El-Sawalhi, R.; Lux, J.; Salagnac, P.

    2016-08-01

    In this work, we are interested in the structural and thermal characterization of natural fiber insulation materials. The thermal performance of these materials depends on the arrangement of fibers, which is the consequence of the manufacturing process. In order to optimize these materials, thermal conductivity models can be used to correlate some relevant structural parameters with the effective thermal conductivity. However, only a few models are able to take into account the anisotropy of such material related to the fibers orientation, and these models still need realistic input data (fiber orientation distribution, porosity, etc.). The structural characteristics are here directly measured on a 3D tomographic image using advanced image analysis techniques. Critical structural parameters like porosity, pore and fiber size distribution as well as local fiber orientation distribution are measured. The results of the tested conductivity models are then compared with the conductivity tensor obtained by numerical simulation on the discretized 3D microstructure, as well as available experimental measurements. We show that 1D analytical models are generally not suitable for assessing the thermal conductivity of such anisotropic media. Yet, a few anisotropic models can still be of interest to relate some structural parameters, like the fiber orientation distribution, to the thermal properties. Finally, our results emphasize that numerical simulations on 3D realistic microstructure is a very interesting alternative to experimental measurements.

  8. Thermally Activated Motion of Sodium Cations in Insulating Parent Low-Silica X Zeolite

    Science.gov (United States)

    Igarashi, Mutsuo; Jeglič, Peter; Mežnaršič, Tadej; Nakano, Takehito; Nozue, Yasuo; Watanabe, Naohiro; Arčon, Denis

    2017-07-01

    We report a 23Na spin-lattice relaxation rate, T1 - 1, in low-silica X zeolite. T1 - 1 follows multiple BPP-type behavior as a result of thermal motion of sodium cations in insulating material. The estimated lowest activation energy of 15 meV is much lower than 100 meV observed previously for sodium motion in heavily Na-loaded samples and is most likely attributed to short-distance jumps of sodium cations between sites within the same supercage.

  9. Thermal insulation research plan for the Energy Conversion and Utilization Technologies (ECUT) materials program

    Energy Technology Data Exchange (ETDEWEB)

    Fine, H.A.

    1986-08-01

    This report documents both the process and the output of the process of establishing a peer review panel primarily from the private sector to suggest research and development activities appropriate for government sponsorship through the US Department of Energy (DOE) Energy Conversion and Utilization Technologies (ECUT) Program on the subject of thermal insulation. We expect to use information and guidance from the document during the federal budgetary process to allow more informed decision making. All related results of that budgetary decision making will affect what the DOE or Oak Ridge National Laboratory (ORNL) can and will sponsor during this or subsequent years through detailed decisions of DOE and ORNL program managers.

  10. THE INFLUENCE OF ECOLOGICAL MATERIALS EMBEDDED INTO COMPOSITES UPON THE THERMAL INSULATING CAPACITY

    Directory of Open Access Journals (Sweden)

    Luminiţa-Maria BRENCI

    2014-12-01

    Full Text Available The paper presents the results of a research performed in order to design and manufacture composites that embed in their structure ecological raw materials, such as wood chips and hemp hurds. The thermal conductivity was determined for a temperature difference (ΔT of 200 C between the cold plate and warm plate and the measurements were done in eight points. The results showed that the best insulating composite material was obtained for the structure containing equal shares of wood chips and chopped hemp

  11. The production line of bio-fibre based thermal insulation materials. Feasibility study; Kasvikuitueristeiden tuotantoketjun toteutettavuus

    Energy Technology Data Exchange (ETDEWEB)

    Rissanen, R. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Structural Engineering and Building Physics; Pasila, A.; Kymaelaeinen, H.R. [Helsinki Univ. (Finland). Faculty of Agriculture and Forestry

    1998-10-01

    The alternatives of the production line of bio-fibre based thermal insulation materials and the preconditions for economical Finnish production were estimated in a feasibility study. On the basis of existing results, the quality and the competitiveness of the bio-fibre based thermal insulation materials were compared with the other thermal insulation materials on the market. The acceptance procedure of authorities and the quality control were also examined. Compared with the mineral wool product, the strongest competitive advantages of bio-fibre based thermal insulation are the natural raw materials and an environmentally friendly image. With the Finnish bio-fibre insulation production, we can meet the growing demand for ecological building materials. The constructions used in Germany and the experience derived from them cannot be applied directly to Finnish conditions. The behaviour of the biofibres must be known so that they can be used in building constructions. Types and quantities of additives and adhesives used in insulation must be determined within the production design part In the beginning of the production line the method of growing, harvesting, storing and drying can be similar to any article. The aim of the development of the growing and harvesting technique is to create the most fluent and economical production of raw material. The so called dry-line method must be developed in order to reduce the production costs of short flax fibre. The principal aim in choosing the storing and drying methods is to make sure that the raw material will stay in good condition and be homogeneous. The moulding risk must be taken into account during the whole production line. The pre-processing of bio-fibres can be carried out either in farms or in a production unit. A rather big preprocessing terminal or a mobile grinding unit could be constructed for farms situated close to each other. The unit could be transferred between farms. In these cases the transport costs

  12. Investigation of thermal and electrical stabilities of a GdBCO coil using grease as an insulation material for practical superconducting applications.

    Science.gov (United States)

    Kang, D H; Kim, K L; Kim, Y G; Park, Y J; Kim, W J; Kim, S H; Lee, H G

    2014-09-01

    This paper presents the effects of thermal grease on the electrical and thermal characteristics of GdBCO pancake coils, observed through charge-discharge, sudden discharge, over-current, and thermal quench testing. In charge-discharge and sudden discharge tests, a coil using thermal grease as an insulation material demonstrated faster charging/discharging rates compared to a coil without turn-to-turn insulation. In the case of over-current tests, the coil using thermal grease exhibited the highest electrical stability. Furthermore, thermal quench testing showed the coil employing thermal grease to possess superior thermal characteristics, with rapid cooling and low temperature rise. Overall, the use of thermal grease as an insulation material may be a potential solution to the problems observed with the existing insulation materials, possessing fast charging/discharging rates with superior thermal and electrical stabilities.

  13. CO2 Insulation for Thermal Control of the Mars Science Laboratory

    Science.gov (United States)

    Bhandari, Pradeep; Karlmann, Paul; Anderson, Kevin; Novak, Keith

    2011-01-01

    The National Aeronautics and Space Administration (NASA) is sending a large (>850 kg) rover as part of the Mars Science Laboratory (MSL) mission to Mars in 2011. The rover's primary power source is a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) that generates roughly 2000 W of heat, which is converted to approximately 110 W of electrical power for use by the rover electronics, science instruments, and mechanism-actuators. The large rover size and extreme thermal environments (cold and hot) for which the rover is designed for led to a sophisticated thermal control system to keep it within allowable temperature limits. The pre-existing Martian atmosphere of low thermal conductivity CO2 gas (8 Torr) is used to thermally protect the rover and its components from the extremely cold Martian environment (temperatures as low as -130 deg C). Conventional vacuum based insulation like Multi Layer Insulation (MLI) is not effective in a gaseous atmosphere, so engineered gaps between the warm rover internal components and the cold rover external structure were employed to implement this thermal isolation. Large gaps would lead to more thermal isolation, but would also require more of the precious volume available within the rover. Therefore, a balance of the degree of thermal isolation achieved vs. the volume of rover utilized is required to reach an acceptable design. The temperature differences between the controlled components and the rover structure vary from location to location so each gap has to be evaluated on a case-by-case basis to arrive at an optimal thickness. For every configuration and temperature difference, there is a critical thickness below which the heat transfer mechanism is dominated by simple gaseous thermal conduction. For larger gaps, the mechanism is dominated by natural convection. In general, convection leads to a poorer level of thermal isolation as compared to conduction. All these considerations play important roles in the

  14. An effect of heat insulation parameters on thermal losses of water-cooled roofs for secondary steelmaking electric arc furnaces

    Directory of Open Access Journals (Sweden)

    E. Mihailov

    2016-07-01

    Full Text Available The aim of this work is research in the insulation parameters effect on the thermal losses of watercooled roofs for secondary steelmaking electric arc furnaces. An analytical method has been used for the investigation in heat transfer conditions in the working area. The results of the research can be used to choose optimal cooling parameters and select a suitable kind of insulation for water-cooled surfaces.

  15. Comparative Study on Accelerated Thermal Ageing of Vegetable Insulating Oil-paperboard and Mineral Oil-paperboard

    Science.gov (United States)

    Zhou, Zhu-Jun; Hu, Ting; Cheng, Lin; Tian, Kai; Yang, Jun; Wang, Xuan; Fang, Fu-Xin; Kong, Hai-Yang; Qian, Hang

    2016-05-01

    To comparatively study the insulation ageing life of vegetable insulating oil-paperboard and mineral oil-paperboard, we conducted accelerated thermal ageing experiments at 170°C. Then according to the temperature rise of vegetable insulating oil transformer, we conducted accelerated thermal ageing experiments at 150°C for vegetable insulating oil-paperboard and at 140°C for mineral oil-paperboard. The appearance, polymerization degree, and SEM microstructure of the paperboard after different ageing experiments were comparative analyzed. The results show that after the oil-paperboard system is accelerated ageing for 1 000 h at 170°C, that is equivalent to 20 years natural ageing, the structure of paperboard in vegetable insulating oil is damaged severely, which indicates that the lifetime of transformer are in the late stage; while the structure of paperboard in mineral oil maintain complete, and the polymerization degree is still above 500, which indicate that the lifetime of transformer are in the middle stage. The accelerated ageing rate of the vegetable insulating oil-paperboard system at 150°C is slower than that of the mineral oil-paperboard system, which indicates that the lifetime of the vegetable insulating oil-paperboard is longer than that of the mineral oil-paperboard.

  16. Protection against cold in prehospital care-thermal insulation properties of blankets and rescue bags in different wind conditions.

    Science.gov (United States)

    Henriksson, Otto; Lundgren, J Peter; Kuklane, Kalev; Holmér, Ingvar; Bjornstig, Ulf

    2009-01-01

    In a cold, wet, or windy environment, cold exposure can be considerable for an injured or ill person. The subsequent autonomous stress response initially will increase circulatory and respiratory demands, and as body core temperature declines, the patient's condition might deteriorate. Therefore, the application of adequate insulation to reduce cold exposure and prevent body core cooling is an important part of prehospital primary care, but recommendations for what should be used in the field mostly depend on tradition and experience, not on scientific evidence. The objective of this study was to evaluate the thermal insulation properties in different wind conditions of 12 different blankets and rescue bags commonly used by prehospital rescue and ambulance services. The thermal manikin and the selected insulation ensembles were setup inside a climatic chamber in accordance to the modified European Standard for assessing requirements of sleeping bags. Fans were adjusted to provide low (thermal transfer, the total resultant insulation value, Itr (m2 C/Wclo; where C = degrees Celcius, and W = watts), was calculated from ambient air temperature (C), manikin surface temperature (C), and heat flux (W/m2). In the low wind condition, thermal insulation of the evaluated ensembles correlated to thickness of the ensembles, ranging from 2.0 to 6.0 clo (1 clo = 0.155 m2 C/W), except for the reflective metallic foil blankets that had higher values than expected. In moderate and high wind conditions, thermal insulation was best preserved for ensembles that were windproof and resistant to the compressive effect of the wind, with insulation reductions down to about 60-80% of the original insulation capacity, whereas wind permeable and/or lighter materials were reduced down to about 30-50% of original insulation capacity. The evaluated insulation ensembles might all be used for prehospital protection against cold, either as single blankets or in multiple layer combinations

  17. Improving thermal insulation of TC4 using YSZ-based coating and SiO2 aerogel

    Directory of Open Access Journals (Sweden)

    Lei Jin

    2015-04-01

    Full Text Available In this paper, air plasmas spray (APS was used to prepare YSZ and Sc2O3–YSZ (ScYSZ coating in order to improve the thermal insulation ability of TC4 alloy. SiO2 aerogel was also synthesized and affixed on TC4 titanium alloy to inhabit thermal flow. The microstructures, phase compositions and thermal insulation performance of three coatings were analyzed in detail. The results of thermal diffusivity test by a laser flash method showed that the thermal diffusivities of YSZ, Sc2O3–YSZ and SiO2 aerogel are 0.553, 0.539 and 0.2097×10−6 m2/s, respectively. Then, the thermal insulation performances of three kinds of coating were investigated from 20 °C to 400 °C using high infrared radiation heat flux technology. The experimental results indicated that the corresponding temperature difference between the top TC4 alloy (400 °C and the bottom surface of YSZ is 41.5 °C for 0.6 mm thickness coating. For 1 mm thickness coating, the corresponding temperature difference between the top TC4 alloys (400 °C and the bottom surface of YSZ, ScYSZ, SiO2 aerogel three specimens is 54, 54.6 and 208 °C, respectively. The coating thickness and species were found to influence the heat insulation ability. In these materials, YSZ and ScYSZ exhibited a little difference for heat insulation behavior. However, SiO2 aerogel was the best one among them and it can be taken as protection material on TC4 alloys. In outer space, SiO2 aerogel can meet the need of thermal insulation of TC4 of high-speed aircraft.

  18. Improvement of thermal stability of insulation paper cellulose by modified polysiloxane grafting

    Science.gov (United States)

    Zhang, Song; Tang, Chao; Xie, Jingyu; Zhou, Qu

    2016-10-01

    We present a method for improving the thermal stability of insulation paper cellulose. A polysiloxane was grafted to the hydroxyl group connected to the C6 atom in the cellulose chain. The effects of the mass fraction of polysiloxane on the mechanical properties and glass-transition temperatures of model cellulose samples modified by polysiloxane grafting were investigated using molecular dynamics simulations. The results show that for four models, with polysiloxane mass fractions of 0%, 3.3%, 6.5%, and 12.2%, the best chain performance was achieved using a mass fraction of 6.5%. The glass-transition temperature of the modified cellulose with a 6.5% mass fraction of polysiloxane was 48 K higher than that of unmodified cellulose, which shows that modification improved the thermal stability of the cellulose.

  19. An application of vacuum insulated tubing (VIT) in a SAGD thermal completion at Surmont

    Energy Technology Data Exchange (ETDEWEB)

    Handfield, T.C.; Martin, W.; Spenceley, N. [ConocoPhillips (Canada); Banman, R.M. [Total EandP (Canada)

    2011-07-01

    In the oil sands industry, steam assisted gravity drainage (SAGD) is a thermal recovery method. During the preheating of an SAGD well pair, high quality steam is injected down hole through the long string while return fluids are returned to the surface through the short string; this situation leads to unwanted heat exchanges between the two. The aim of the study is to determine the possible benefits of using acuum insulated tubing (VIT), a technology which manages downhole temperature successfully, in the SAGD process. A theoretical analysis and a field test were conducted on 2 injection wells in an in-situ oil sands project in Surmont in the Athabasca area. Results showed that the use of VIT improves heat transfer efficiency, leading to lower steam injection requirements and a reduction of concerns relating to thermal expansion and well integrity. This paper demonstrated that the application of VIT to the SAGD process is beneficial.

  20. Influence of iron on crystallization behavior and thermal stability of the insulating materials - porous calcium silicates

    DEFF Research Database (Denmark)

    Haastrup, Sonja; Yu, Donghong; Yue, Yuanzheng

    2017-01-01

    The properties of porous calcium silicate for high temperature insulation are strongly influenced by impurities. In this work we determine the influence of Fe3+ on the crystallization behavior and thermal stability of hydrothermally derived calcium silicate. We synthesize porous calcium silicate...... by XRD analysis. The thermal stability and compressive strength of the calcium silicates are seriously influenced by the changes of their crystal structure. Linear shrinkage of the reference sample is 1.3% at 1050°C, whereas the sample with Fe/Si =1.0% does by 30.4%. In conclusion, the presence of Fe3......+ modifies the crystal structure of porous calcium silicates, leading to a significant shrinkage in these materials....

  1. Low-cost and fast synthesis of nanoporous silica cryogels for thermal insulation applications.

    Science.gov (United States)

    Su, Li Fen; Miao, Lei; Tanemura, Sakae; Xu, Gang

    2012-06-01

    Nanoporous silica cryogels with a high specific surface area of 1095 m2 g-1 were fabricated using tert-butyl alcohol as a reaction solvent, via a cost-effective sol-gel process followed by vacuum freeze drying. The total time of cryogel production was reduced markedly to one day. The molar ratio of solvent/precursor, which was varied from 5 to 13, significantly affected the porous structure and thermal insulating properties of the cryogels. The silica cryogels with low densities in the range of 0.08-0.18 g cm-3 and thermal conductivities as low as 6.7 mW (m·K)-1 at 100 Pa and 28.3 mW (m·K)-1 at 105 Pa were obtained using this new technique.

  2. Synthesis of Hollow Silica Nanospheres by Sacrificial Polystyrene Templates for Thermal Insulation Applications

    Directory of Open Access Journals (Sweden)

    Linn Ingunn C. Sandberg

    2013-01-01

    Full Text Available Monodisperse polystyrene (PS spheres with controllable size have been synthesized by a straight forward and simple procedure. The as-synthesized PS spheres have a typical diameter ranging from ~180 nm to ~900 nm, where a reduced sphere size is obtained by increasing the polyvinylpyrrolidone (PVP/styrene weight ratio. The PS spheres function as sacrificial templates for the fabrication of hollow silica nanospheres (HSNSs for thermal insulation applications. By modifying the silica coating process, HSNSs with different surface roughness are obtained. All resulting HSNSs show typically a thermal conductivity of about 20 mW/(mK, indicating that the surface phonon scattering is probably not significant in these HSNS samples.

  3. Development of fly ash boards with thermal, acoustic and fire insulation properties.

    Science.gov (United States)

    Leiva, C; Arenas, C; Vilches, L F; Alonso-Fariñas, B; Rodriguez-Galán, M

    2015-12-01

    This paper presents an experimental analysis on a new board composed of gypsum and fly ashes from coal combustion, which are mutually compatible. Physical and mechanical properties, sound absorption coefficient, thermal properties and leaching test have been obtained. The mechanical properties showed similar values to other commercial products. As far as the acoustic insulation characteristics are concerned, sound absorption coefficients of 0.3 and 0.8 were found. The board presents a low thermal conductivity and a fire resistance higher than 50 min (for 4 cm of thickness). The leaching of trace elements was below the leaching limit values. These boards can be considered as suitable to be used in building applications as partitions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Low-cost and fast synthesis of nanoporous silica cryogels for thermal insulation applications

    Directory of Open Access Journals (Sweden)

    Li Fen Su, Lei Miao, Sakae Tanemura and Gang Xu

    2012-01-01

    Full Text Available Nanoporous silica cryogels with a high specific surface area of 1095 m2 g−1 were fabricated using tert-butyl alcohol as a reaction solvent, via a cost-effective sol–gel process followed by vacuum freeze drying. The total time of cryogel production was reduced markedly to one day. The molar ratio of solvent/precursor, which was varied from 5 to 13, significantly affected the porous structure and thermal insulating properties of the cryogels. The silica cryogels with low densities in the range of 0.08–0.18 g cm−3 and thermal conductivities as low as 6.7 mW (mcenterdotK−1 at 100 Pa and 28.3 mW (mcenterdotK−1 at 105 Pa were obtained using this new technique.

  5. Synthesis of Flexible Aerogel Composites Reinforced with Electrospun Nanofibers and Microparticles for Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Huijun Wu

    2013-01-01

    Full Text Available Flexible silica aerogel composites in intact monolith of 12 cm were successfully fabricated by reinforcing SiO2 aerogel with electrospun polyvinylidene fluoride (PVDF webs via electrospinning and sol-gel processing. Three electrospun PVDF webs with different microstructures (e.g., nanofibers, microparticles, and combined nanofibers and microparticles were fabricated by regulating electrospinning parameters. The as-electrospun PVDF webs with various microstructures were impregnated into the silica sol to synthesize the PVDF/SiO2 composites followed by solvent exchange, surface modification, and drying at ambient atmosphere. The morphologies of the PVDF/SiO2 aerogel composites were characterized and the thermal and mechanical properties were measured. The effects of electrospun PVDF on the thermal and mechanical properties of the aerogel composites were evaluated. The aerogel composites reinforced with electrospun PVDF nanofibers showed intact monolith, improved strength, and perfect flexibility and hydrophobicity. Moreover, the aerogel composites reinforced with the electrospun PVDF nanofibers had the lowest thermal conductivity (0.028 W·m−1·K−1. It indicates that the electrospun PVDF nanofibers could greatly improve the mechanical strength and flexibility of the SiO2 aerogels while maintaining a lower thermal conductivity, which provides increasing potential for thermal insulation applications.

  6. Study on mechanical and ablative properties of EPDM/OMMT thermal insulating nanocomposites.

    Science.gov (United States)

    Gao, Guoxin; Zhang, Zhicheng; Li, Xuefei; Meng, Qingjie; Zheng, Yuansuo; Jin, Zhihao

    2010-11-01

    In order to enhance the elongation at break, the ablation resistant properties as well as the tensile strength of the thermal insulating materials, organo-montmorillonite (OMMT) was introduced into the short aramid fibers reinforced Ethylene-Propylene-Diene Monomer (EPDM) based nanocomposites. The effects of OMMT content on the mechanical and ablative properties of the nanocomposites were investigated systematically. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirm that EPDM-matrix has been intercalated into OMMT interlayers after a mixing process on a two-roll mill. The brittle fracture of nanocomposites also indicates that OMMT can lubricate aramid fiber to weaken the interfacial adhesive strength between the fibers and the matrix. As a result, the tensile strength and elongation at break are both improved sharply with OMMT content increasing from 1 phr to 7 phr. However, thanks to the inevitable agglomeration of OMMT with high loading inside the nanocomposites, the tensile strength and elongation at break reduce gently once OMMT is over 7 phr. Furthermore, the ablation resistant properties are improved greatly by increasing OMMT from 1 phr to 11 phr. Therefore, the optimal content of OMMT is 7-11 phr for the thermal insulating nanocomposites with big elongation and excellent ablation resistant properties.

  7. Characterisation of net type thermal insulators at 1.8 K low boundary temperature

    CERN Document Server

    Peón-Hernández, G; Szeless, Balázs

    1997-01-01

    The Large Hadron Collider's superconducting magnets are cooled by superfluid helium at 1.8 K and housed in cryostats that minimise the heat inleak to this temperature level by extracting heat at 70 and 5 K. In the first generation of prototype cryostats, the radiative heat to the 1.8 K temperature level accounted for 70 % of the total heat inleak. An alternative to enhance the cryostat thermal performance incorporates a thermalised radiation screen at 5 K. In order to avoid contact between the 5 K radiation screen and the cold mass, insulators are placed between both surfaces. Sets of commercial fibre glass nets are insulator candidates to minimise the heat inleak caused by a accidental contact between the two temperature levels. A model to estimate their performance is presented. A set-up to thermally characterise them has been designed and is also described in the paper. Finally, results as a function of the number of the spacer nets, the boundary temperatures and the compressive force in the spacer are pre...

  8. Development, testing and application of extruded polystyrene foam (XPS) insulation with improved thermal properties; Polystyrol-Extruderschaum mit verbesserten waermetechnischen Eigenschaften - Entwicklung, Pruefung und Anwendung

    Energy Technology Data Exchange (ETDEWEB)

    Bunge, Friedhelm [Forschung und Entwicklung Dow Building Solutions, Horgen (Switzerland); Merkel, Holger [Anwendungstechnik Dow Building Solutions, Schwalbach (Germany)

    2011-02-15

    Improved extruded polystyrene foam (XPS) insulation with lower thermal conductivity has been developed. This enables meeting the increased requirements for sustainable building insulation with better material efficiency. The proven mechanical and hygro-thermal properties of XPS insulation are maintained. This first product generation has been developed primarily for external perimeter insulation of basement walls and floors as well as for the insulation of cavity walls. The CO{sub 2} foaming technology meets the sustainability requirements for building products. (Copyright copyright 2011 Ernst and Sohn Verlag fuer Architektur und technische Wissenschaften GmbH and Co. KG, Berlin)

  9. Defect Detection of Adhesive Layer of Thermal Insulation Materials Based on Improved Particle Swarm Optimization of ECT

    Directory of Open Access Journals (Sweden)

    Yintang Wen

    2017-10-01

    Full Text Available This paper studies the defect detection problem of adhesive layer of thermal insulation materials. A novel detection method based on an improved particle swarm optimization (PSO algorithm of Electrical Capacitance Tomography (ECT is presented. Firstly, a least squares support vector machine is applied for data processing of measured capacitance values. Then, the improved PSO algorithm is proposed and applied for image reconstruction. Finally, some experiments are provided to verify the effectiveness of the proposed method in defect detection for adhesive layer of thermal insulation materials. The performance comparisons demonstrate that the proposed method has higher precision by comparing with traditional ECT algorithms.

  10. Defect Detection of Adhesive Layer of Thermal Insulation Materials Based on Improved Particle Swarm Optimization of ECT.

    Science.gov (United States)

    Wen, Yintang; Jia, Yao; Zhang, Yuyan; Luo, Xiaoyuan; Wang, Hongrui

    2017-10-25

    This paper studies the defect detection problem of adhesive layer of thermal insulation materials. A novel detection method based on an improved particle swarm optimization (PSO) algorithm of Electrical Capacitance Tomography (ECT) is presented. Firstly, a least squares support vector machine is applied for data processing of measured capacitance values. Then, the improved PSO algorithm is proposed and applied for image reconstruction. Finally, some experiments are provided to verify the effectiveness of the proposed method in defect detection for adhesive layer of thermal insulation materials. The performance comparisons demonstrate that the proposed method has higher precision by comparing with traditional ECT algorithms.

  11. Properties of Agro-Industrial Aerated Concrete as Potential Thermal Insulation for Building

    Directory of Open Access Journals (Sweden)

    Aminudin Eeydzah

    2016-01-01

    Full Text Available The present paper is aiming to provide an actual state of the development of non autoclaved Agro-Industrial aerated concrete by using multiple ashes as improvement of thermal behavior for building. The feasibility of Agro-Industrial wastes as lightweight concrete by utilizing the Palm Oil Fuel Ash (POFA as binder replacement and bottom ash as fine aggregate was investigated in this paper. Portland cement, bottom ash, aluminum powder and lime (Ca(OH2 were used in this study. The POFA was used to replace Portland cement and Hydrated Lime at 0%, 5%, 10% and 15% by weight and aluminum powder was added at 0.75% dry weight in order to form bubbles. The compressive strength, water absorption, porosity and the thermal conductivity test were carried out after the concrete were water cured for 7 days and later being exposed to the air and water until 28days. The results show that the 20% replacements give the optimum strength of 7.143MPa and 30% give the best thermal conductivity with 0.48W/mK. Hence, this study aim, was to develop an agro-industrial aerated concrete good in insulation but having an optimum strength. Hence, it has been found that the more the percentage of POFA is added the lower the thermal conductivity since the pore structure is increasing and by the optimization done, 30% replacement has been chosen as the best mix design for Agro-Industrial Aerated Concrete.

  12. Polyurethane Foams for Thermal Insulation Uses Produced from Castor Oil and Crude Glycerol Biopolyols.

    Science.gov (United States)

    Carriço, Camila S; Fraga, Thaís; Carvalho, Vagner E; Pasa, Vânya M D

    2017-07-02

    Rigid polyurethane foams were synthesized using a renewable polyol from the simple physical mixture of castor oil and crude glycerol. The effect of the catalyst (DBTDL) content and blowing agents in the foams' properties were evaluated. The use of physical blowing agents (cyclopentane and n-pentane) allowed foams with smaller cells to be obtained in comparison with the foams produced with a chemical blowing agent (water). The increase of the water content caused a decrease in density, thermal conductivity, compressive strength, and Young's modulus, which indicates that the increment of CO₂ production contributes to the formation of larger cells. Higher amounts of catalyst in the foam formulations caused a slight density decrease and a small increase of thermal conductivity, compressive strength, and Young's modulus values. These green foams presented properties that indicate a great potential to be used as thermal insulation: density (23-41 kg·m-3), thermal conductivity (0.0128-0.0207 W·m-1·K-1), compressive strength (45-188 kPa), and Young's modulus (3-28 kPa). These biofoams are also environmentally friendly polymers and can aggregate revenue to the biodiesel industry, contributing to a reduction in fuel prices.

  13. Polyurethane Foams for Thermal Insulation Uses Produced from Castor Oil and Crude Glycerol Biopolyols

    Directory of Open Access Journals (Sweden)

    Camila S. Carriço

    2017-07-01

    Full Text Available Rigid polyurethane foams were synthesized using a renewable polyol from the simple physical mixture of castor oil and crude glycerol. The effect of the catalyst (DBTDL content and blowing agents in the foams’ properties were evaluated. The use of physical blowing agents (cyclopentane and n-pentane allowed foams with smaller cells to be obtained in comparison with the foams produced with a chemical blowing agent (water. The increase of the water content caused a decrease in density, thermal conductivity, compressive strength, and Young’s modulus, which indicates that the increment of CO2 production contributes to the formation of larger cells. Higher amounts of catalyst in the foam formulations caused a slight density decrease and a small increase of thermal conductivity, compressive strength, and Young’s modulus values. These green foams presented properties that indicate a great potential to be used as thermal insulation: density (23–41 kg·m−3, thermal conductivity (0.0128–0.0207 W·m−1·K−1, compressive strength (45–188 kPa, and Young’s modulus (3–28 kPa. These biofoams are also environmentally friendly polymers and can aggregate revenue to the biodiesel industry, contributing to a reduction in fuel prices.

  14. Experimental Evaluation and Comparison of Thermal Conductivity of High-Voltage Insulation Materials for Vacuum Electronic Devices

    Science.gov (United States)

    Suresh, C.; Srikrishna, P.

    2017-07-01

    Vacuum electronic devices operate with very high voltage differences between their sub-assemblies which are separated by very small distances. These devices also emit large amounts of heat that needs to be dissipated. Hence, there exists a requirement for high-voltage insulators with good thermal conductivity for voltage isolation and efficient heat dissipation. However, these voltage insulators are generally poor conductors of heat. In the present work, an effort has been made to obtain good high-voltage insulation materials with substantial improvement in their thermal conductivity. New mixtures of composites were formed by blending varying percentages (by volumes) of aluminum nitride powders with that of neat room-temperature vulcanizing (RTV) silicone elastomer compound. In this work, a thermal conductivity test setup has been devised for the quantification of the thermal conductivity of the insulators. The thermal conductivities and high-voltage isolation capabilities of various blended composites were quantified and were compared with that of neat RTV to evaluate the relative improvement.

  15. Elastomeric Thermal Insulation Design Considerations in Long, Aluminized Solid Rocket Motors

    Science.gov (United States)

    Martin, Heath T.

    2017-01-01

    An all-new sounding rocket was designed at NASA's Marshall Space Flight Center that featured an aft finocyl, aluminized solid propellant grain and silica-filled ethylene-propylene-diene monomer (SFEPDM) internal insulation. Upon the initial static firing of the first of this new design, the solid rocket motor (SRM) case failed thermally just upstream of the aft closure early in the burn time. Subsequent fluid modeling indicated that the high-velocity combustion-product jets emanating from the fin-slots in the propellant grain were likely inducing a strongly swirling flow, thus substantially increasing the severity of the convective environment on the exposed portion of the SFEPDM insulation in this region. The aft portion of the fin-slots in another of the motors were filled with propellant to eliminate the possibility of both direct jet impingement on the exposed SFEPDM and the appearance of strongly swirling flow in the aft region of the motor. When static-fired, this motor's case still failed in the same axial location, and, though somewhat later than for the first static firing, still in less than 1/3rd of the desired burn duration. These results indicate that the extreme material decomposition rates of the SFEPDM in this application are not due to gas-phase convection or shear but rather to interactions with burning aluminum or alumina slag. Further comparisons with between SFEPDM performance in this design and that in other hot-fire tests provide insight into the mechanisms of SFEPDM decomposition in SRM aft domes that can guide the upcoming redesign effort, as well as other future SRM designs. These data also highlight the current limitations of modeling elastomeric insulators solely with diffusion-controlled, gas-phase thermochemistry in SRM regions with significant viscous shear and/or condense-phase impingement or flow.

  16. Micro thermal diode with glass thermal insulation structure embedded in a vapor chamber

    Science.gov (United States)

    Tsukamoto, Takashiro; Hirayanagi, Takashi; Tanaka, Shuji

    2017-04-01

    This paper reports a micro thermal diode based on one-way working fluid circulation driven by surface tension force. In forward mode, working fluid evaporates and condenses at a heated and cooled area, respectively, and the condensed liquid returns to the evaporation area due to the wettability difference. By this vapor-liquid phase change mechanism, the overall heat transfer coefficient becomes high. On the other hand, in reverse mode, no continuous evaporation-condensation cycle exists. The conductive heat loss in reverse mode was minimized by an embedded glass thermal isolation structure, which makes overall heat transfer coefficient low. The test device was made by a standard MEMS process combined with glass reflow and gold bump sealing. The overall heat transfer coefficients of 13 300 \\text{W}~{{\\text{m}}-2}~\\text{K} for forward mode and 4790 \\text{W}~{{\\text{m}}-2}~\\text{K} for reverse mode were measured. The performance index of the micro thermal diode was about 2.8.

  17. Thermal Stability of Modified Insulation Paper Cellulose Based on Molecular Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    Chao Tang

    2017-03-01

    Full Text Available In this paper, polysiloxane is used to modify insulation paper cellulose, and molecular dynamics methods are used to evaluate the glass transition temperature and mechanical properties of the paper before and after the modification. Analysis of the static mechanical performance of the model shows that, with increasing temperature, the elastic modulus of both the modified and unmodified cellulose models decreases gradually. However, the elastic modulus of the modified model is greater than that of the unmodified model. Using the specific volume method and calculation of the mean square displacement of the models, the glass transition temperature of the modified cellulose model is found to be 48 K higher than that of the unmodified model. Finally, the changes in the mechanical properties and glass transition temperature of the model are analyzed by energy and free volume theory. The glass transition temperatures of the unmodified and modified cellulose models are approximately 400 K and 450 K, respectively. These results are consistent with the conclusions obtained from the specific volume method and the calculation of the mean square displacement. It can be concluded that the modification of insulation paper cellulose with polysiloxane will effectively improve its thermal stability.

  18. Study on the Thermal Properties of Hollow Shale Blocks as Self-Insulating Wall Materials

    Directory of Open Access Journals (Sweden)

    Guo-liang Bai

    2017-01-01

    Full Text Available To reduce energy consumption and protect the environment, a type of hollow shale block with 29 rows of holes was designed and produced. This paper investigated the thermal properties of hollow shale blocks and walls. First, the guarding heat-box method was used to obtain the heat transfer coefficient of the hollow shale block walls. The experimental heat transfer coefficient is 0.726 W/m2·K, which would save energy compared to traditional wall materials. Then, the theoretical value of the heat transfer coefficient was calculated to be 0.546 W/m2·K. Furthermore, the one-dimensional steady heat conduction process for the block and walls was simulated using the finite element analysis software ANSYS. The predicted heat transfer coefficient for the walls was 0.671 W/m2·K, which was in good agreement with the test results. With the outstanding self-insulation properties, this type of hollow shale block could be used as a wall material without any additional insulation measures in masonry structures.

  19. A Novel Environmental Route to Ambient Pressure Dried Thermal Insulating Silica Aerogel via Recycled Coal Gangue

    Directory of Open Access Journals (Sweden)

    Pinghua Zhu

    2016-01-01

    Full Text Available Coal gangue, one of the main hazardous emissions of purifying coal from coalmine industry, is rich in silica and alumina. However, the recycling of the waste is normally restricted by less efficient techniques and low attractive output; the utilization of such waste is still staying lower than 15%. In this work, the silica aerogel materials were synthesized by using a precursor extracted from recycled silicon-rich coal gangue, followed by a single-step surface silylation and ambient pressure drying. A low density (~0.19 g/cm3 nanostructured aerogel with a 3D open porous microstructure and high surface area (~690 m2/g was synthesized, which presents a superior thermal insulation performance (~26.5 mW·m−1·K−1 of a plane packed of 4-5 mm granules which was confirmed by transient hot-wire method. This study offers a new facile route to the synthesis of insulating aerogel material by recycling solid waste coal gangue and presents a potential cost reduction of industrial production of silica aerogels.

  20. Foam nests provide context-dependent thermal insulation to embryos of three leptodactylid frogs.

    Science.gov (United States)

    Méndez-Narváez, J; Flechas, S V; Amézquita, A

    2015-01-01

    The choice of adequate breeding habitat and its associated thermoregulatory conditions are thought to be important in the evolution of amphibian reproductive strategies. Among leptodactylid frogs, there is a terrestrial cline in the oviposition sites chosen to build foam nests for eggs. Although several functions have been attributed to foam nests, their role in temperature regulation for embryos is unclear. Here we tested the hypothesis that foam nests buffer embryos from variation in air temperature. We examined the degree of terrestrial nest sites in three species, finding a terrestrial cline of sites in terms of distance from water. We tested whether this nest-insulation effect varied among these species that differ in the degree of terrestrial nest sites and whether translocating nests impacted embryonic mortality. Our results demonstrate a negative effect of translocating aquatic nests to land, inferred from the highest hatching success in natural nests sites. All nests attenuated environmental thermal variation, but more terrestrial nests buffered embryos from a greater range of temperatures than did aquatic ones. Altogether, our data indicate that foam nests insulate embryos from daily temperature fluctuations among leptodactylid frogs with different degrees of terrestrial nests, which may well have contributed to the evolution of this reproductive strategy.

  1. Using thermal balance model to determine optimal reactor volume and insulation material needed in a laboratory-scale composting reactor.

    Science.gov (United States)

    Wang, Yongjiang; Pang, Li; Liu, Xinyu; Wang, Yuansheng; Zhou, Kexun; Luo, Fei

    2016-04-01

    A comprehensive model of thermal balance and degradation kinetics was developed to determine the optimal reactor volume and insulation material. Biological heat production and five channels of heat loss were considered in the thermal balance model for a representative reactor. Degradation kinetics was developed to make the model applicable to different types of substrates. Simulation of the model showed that the internal energy accumulation of compost was the significant heat loss channel, following by heat loss through reactor wall, and latent heat of water evaporation. Lower proportion of heat loss occurred through the reactor wall when the reactor volume was larger. Insulating materials with low densities and low conductive coefficients were more desirable for building small reactor systems. Model developed could be used to determine the optimal reactor volume and insulation material needed before the fabrication of a lab-scale composting system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Determination of Optimum Thermal Insulation Thicknesses for External Walls Considering the Heating, Cooling and Annual Energy Requirement

    Directory of Open Access Journals (Sweden)

    Ömer KAYNAKLI

    2016-06-01

    Full Text Available In this study, optimization of thermal insulation thickness applied to the external walls of buildings has been carried out comparatively based on the seasonal (space-heating and cooling and the annual energy requirements considering solar radiation effect. This study has been performed for four degree-day regions of Turkey, namely, Iskenderun (in the first region, Istanbul (in the second region, Ankara (in the third region and Ardahan (in the fourth region. By determining the sol-air temperatures for each region and maximizing the present worth value of seasonal and annual energy savings, the optimum thermal insulation thicknesses have been calculated. The effects of solar radiation on heating-cooling energy requirements, the variation of optimum insulation thicknesses and payback periods with respect to degree-day regions, the differences between the analyses based on seasonal and annual have been presented in tabular and graphical form.

  3. Aeroelastic analysis of versatile thermal insulation (VTI) panels with pinched boundary conditions

    Science.gov (United States)

    Carrera, Erasmo; Zappino, Enrico; Patočka, Karel; Komarek, Martin; Ferrarese, Adriano; Montabone, Mauro; Kotzias, Bernhard; Huermann, Brian; Schwane, Richard

    2014-03-01

    Launch vehicle design and analysis is a crucial problem in space engineering. The large range of external conditions and the complexity of space vehicles make the solution of the problem really challenging. The problem considered in the present work deals with the versatile thermal insulation (VTI) panel. This thermal protection system is designed to reduce heat fluxes on the LH2 tank during the long coasting phases. Because of the unconventional boundary conditions and the large-scale geometry of the panel, the aeroelastic behaviour of VTI is investigated in the present work. Known available results from literature related to similar problem, are reviewed by considering the effect of various Mach regimes, including boundary layer thickness effects, in-plane mechanical and thermal loads, non-linear effects and amplitude of limit cycle oscillations. A dedicated finite element model is developed for the supersonic regime. The models used for coupling the orthotropic layered structural model with Piston Theory aerodynamic models allow the calculations of flutter conditions in case of curved panels supported in a discrete number of points. An advanced computational aeroelasticity tool is developed using various dedicated commercial softwares (CFX, ZAERO, EDGE). A wind tunnel test campaign is carried out to assess the computational tool in the analysis of this type of problem.

  4. Guar gum benzoate nanoparticle reinforced gelatin films for enhanced thermal insulation, mechanical and antimicrobial properties.

    Science.gov (United States)

    Kundu, Sonia; Das, Aatrayee; Basu, Aalok; Abdullah, Md Farooque; Mukherjee, Arup

    2017-08-15

    This work relates to guar gum benzoate self assembly nanoparticles synthesis and nano composite films development with gelatin. Guar gum benzoate was synthesized in a Hofmeister cation guided homogeneous phase reaction. Self assembly polysaccharide nanoparticles were prepared in solvent displacement technique. Electron microscopy and DLS study confirmed uniform quasi spherical nanoparticles with ζ-potential - 28.7mV. Nanocomposite films were further developed in gelatin matrix. The film capacity augmenting due to nanoparticles incorporation was noteworthy. Superior barrier properties, reinforcing and thermal insulation effects were observed in films dispersed with 20% w/w nanoparticles. Detailed FTIR studies and thermal analysis confirmed nanoparticles interactions in the film matrix. The nanocomposite film water vapour permeability was at 0.75gmm-1kPa-1h-1, thermal conductivity 0.39Wm-1K-1 and the tensile strength were recorded at 3.87MPa. The final film expressed excellent antimicrobial properties against water born gram negative and gram positive bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. External Thermal Insulation Composite Systems: Critical Parameters for Surface Hygrothermal Behaviour

    Directory of Open Access Journals (Sweden)

    Eva Barreira

    2014-01-01

    Full Text Available External Thermal Insulation Composite Systems (ETICS are often used in Europe. Despite its thermal advantages, low cost, and ease of application, this system has serious problems of biological growth causing the cladding defacement. Recent studies pointed that biological growth is due to high values of surface moisture content, which mostly results from the combined effect of exterior surface condensation, wind-driven rain, and drying process. Based on numerical simulation, this paper points the most critical parameters involved in hygrothermal behaviour of ETICS, considering the influence of thermal and hygric properties of the external rendering, the effect of the characteristics of the façade, and the consequences of the exterior and interior climate on exterior surface condensation, wind-driven rain, and drying process. The model used was previously validated by comparison with the results of an “in situ” campaign. The results of the sensitivity analyses show that relative humidity and temperature of the exterior air, atmospheric radiation, and emissivity of the exterior rendering are the parameters that most influence exterior surface condensation. Wind-driven rain depends mostly on horizontal rain, building’s height, wind velocity, and orientation. The drying capacity is influenced by short-wave absorbance, incident solar radiation, and orientation.

  6. Thermal Insulation System Analysis Tool (TISTool) User's Manual. Version 1.0.0

    Science.gov (United States)

    Johnson, Wesley; Fesmire, James; Leucht, Kurt; Demko, Jonathan

    2010-01-01

    The Thermal Insulation System Analysis Tool (TISTool) was developed starting in 2004 by Jonathan Demko and James Fesmire. The first edition was written in Excel and Visual BasIc as macros. It included the basic shapes such as a flat plate, cylinder, dished head, and sphere. The data was from several KSC tests that were already in the public literature realm as well as data from NIST and other highly respectable sources. More recently, the tool has been updated with more test data from the Cryogenics Test Laboratory and the tank shape was added. Additionally, the tool was converted to FORTRAN 95 to allow for easier distribution of the material and tool. This document reviews the user instructions for the operation of this system.

  7. Response Surface Methodology for Design of Porous Hollow Sphere Thermal Insulator

    Science.gov (United States)

    Shohani, Nazanin; Pourmahdian, Saeed; Shirkavand Hadavand, Behzad

    2017-11-01

    In this study, response surface method is used for synthesizing polystyrene (PS) as sacrificial templates and optimizing the particle size. Three factors of initiator, stabilizer concentration and also stirring rate were selected as variable factors. Then, three different concentration of tetraethyl orthosilicate (TEOS) added to reaction media and core-shell structure with PS core and silica shell was developed. Finally, core-shell structure was changed to hollow silica sphere for using as thermal insulator. We observed that increased initiator concentration caused to larger PS particles, increase the stirring rate caused the smaller PS and also with increased the stabilizer concentration obtained that particle size decrease then after 2.5% began to increase. Also the optimum amount of TEOS was found.

  8. A vacuum system for the thermal insulation of the SciFi distribution lines and manifolds

    CERN Document Server

    Joram, Christian

    2017-01-01

    This note describes some calculations and estimates for the layout, technology choice and performance of a vacuum system which shall ensure thermal insulation of the distribution lines and manifolds of the SiPM cooling system of the LHCb SciFi detector. We estimate the heat losses in concentric corrugated stainless steel pipes which leads to the conclusion that the pipes need to be evacuated to a pressure of about 1·10$^{-4}$ mbar. We then estimate the pumping conductance of the pipes and find that it will dominate over the effective pumping speed of any pump. We therefore conclude that a turbo molecular pump of small nominal pumping speed, which can easily achieve end pressures below 10$^{-5}$ mbar is adequate for this purpose. A preliminary layout of the vacuum system is being discussed at the end of the document.

  9. Investigation of energy efficiency of innovate thermal insulating materials and their influence on the building heat regime

    Directory of Open Access Journals (Sweden)

    Morozov Maxim N.

    2015-01-01

    Full Text Available A complex model of heat supply system of building was developed by using Matlab. The model allows conducting for a wide range of research related to improving the energy efficiency of buildings. In this work the investigations of energy efficiency of several advanced insulation materials, which is characterized by different thermal characteristics, were carried out. Conclusions about the impact of the thermal protective envelope on the room thermal regime were made. Prognostic heat consumptions values of rooms with different characteristics of thermal insulation materials and main base-load envelopes were determined. Researches were conducted for the winter climatic conditions of Western Siberia: the average daily outdoor temperature is -22 °C, the amplitude of temperature oscillation is 8 °C.

  10. A Study on Variation of Thermal Characteristics of Insulation Materials for Buildings According to Actual Long-Term Annual Aging Variation

    Science.gov (United States)

    Choi, Hyun-Jung; Kang, Jae-Sik; Huh, Jung-Ho

    2018-01-01

    Insulation materials used for buildings are broadly classified as organic insulation materials or inorganic insulation materials. Foam gas is used for producing organic insulation materials. The thermal conductivity of foam gas is generally lower than that of air. As a result, foam gas is discharged over time and replaced by outside air that has relatively less thermal resistance. The gas composition ratio in air bubbles inside the insulation materials changes rapidly, causing the performance degradation of insulation materials. Such performance degradation can be classified into different stages. Stage 1 appears to have a duration of 5 years, and Stage 2 takes a period of over 10 years. In this study, two insulation materials that are most frequently used in South Korea were analyzed, focusing on the changes thermal resistance for the period of over 5000 days. The measurement result indicated that the thermal resistance of expanded polystyrene fell below the KS performance standards after about 80-150 days from its production date. After about 5000 days, its thermal resistance decreased by 25.7 % to 42.7 % in comparison with the initial thermal resistance. In the case of rigid polyurethane, a pattern of rapid performance degradation appeared about 100 days post-production, and the thermal resistance fell below the KS performance standards after about 1000 days. The thermal resistance decreased by 22.5 % to 27.4 % in comparison with the initial thermal resistance after about 5000 days.

  11. MARCKO thermal insulation layers. Life predictions for thermal insulation and antioxidant layers. Final report; MARCKO-Waermedaemmschichten. Methoden zur Lebensdauervorhersage von Waermedaemm- und Oxidationsschutzschichten. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schuetze, M.

    2003-07-01

    The project was carried out by MTU, Rolls-Royce and Siemens as industrial partners and FZ-Juelich, DLR and DECHEMA as institutes for the purpose of developing a life model for monocrystalline gas turbine blades with metal coatings. This model was to provide reliable information on the life of the ceramic and coupling agent layers. This report describes the activities of the Karl-Winnacker Institute of DECHEMA e.V.: Isothermal oxidation experiments were carried out in the laboratory at 950-1100 degrees centigrade, followed by a characterisation of the oxidation characteristics on the basis of metallographic sections. Particular interest was taken in the development of the TGO (thermally grown oxide) layers, aluminium depletion in the bond coat on the oxide side, and physical defects in the form of pores, pore populations and microcracks within the TGO or in its immediate vicinity. For the first time ever, these microcracks were classified post-experimentally using SEM pictures, and the maximum dimensions of the cracks were quantified as a function of ageing. Kinetics were established for all these parameters. Growth-induced lateral stresses in the TGO were assessed on the basis of the bending of a thin metal foil of pure bond coat material. In the framework of a sub-project carried out by Rolls-Royce, the mechanical characteristics of APS-sprayed thermal insulation layers was investigated in uniaxial pressure experiments on free, hollow cylindrical annular probes. On the one hand, their thermoelastic characteristics were established using path-controlled cyclic load tests; on the other hand, the thermoplastic characteristics were established using load-controlled creep experiments. Samples were used both in the initial and the sintered state in order to assess the effect of sintering, which was described on the basis of porosity as measured in ceramographic sections. The methods and results are presented in this report. [German] In diesem Verbundprojekt, an dem MTU

  12. Load Responsive MLI: Thermal Insulation with High In-Atmosphere and On-Orbit Performance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Long term storage of cryopropellants with minimal loss is required for new Exploration spacecraft. Multi-Layer Insulation (MLI) is used to insulate cryotanks, but is...

  13. Thermal Modeling of the Injection of Standard and Thermally Insulated Cored Wire

    Science.gov (United States)

    Castro-Cedeno, E.-I.; Jardy, A.; Carré, A.; Gerardin, S.; Bellot, J. P.

    2017-09-01

    Cored wire injection is a widespread method used to perform alloying additions during ferrous and non-ferrous liquid metal treatment. The wire consists of a metal casing that is tightly wrapped around a core of material; the casing delays the release of the material as the wire is immersed into the melt. This method of addition presents advantages such as higher repeatability and yield of cored material with respect to bulk additions. Experimental and numerical work has been performed by several authors on the subject of alloy additions, spherical and cylindrical geometries being mainly considered. Surprisingly this has not been the case for cored wire, where the reported experimental or numerical studies are scarce. This work presents a 1-D finite volume numerical model aimed for the simulation of the thermal phenomena which occurs when the wire is injected into a liquid metal bath. It is currently being used as a design tool for the conception of new types of cored wire. A parametric study on the effect of injection velocity and steel casing thickness for an Al cored wire immersed into a steel melt at 1863 K (1590 °C) is presented. The standard single casing wire is further compared against a wire with multiple casings. Numerical results show that over a certain range of injection velocities, the core contents' release is delayed in the multiple casing when compared to a single casing wire.

  14. Thermal Modeling of the Injection of Standard and Thermally Insulated Cored Wire

    Science.gov (United States)

    Castro-Cedeno, E.-I.; Jardy, A.; Carré, A.; Gerardin, S.; Bellot, J. P.

    2017-12-01

    Cored wire injection is a widespread method used to perform alloying additions during ferrous and non-ferrous liquid metal treatment. The wire consists of a metal casing that is tightly wrapped around a core of material; the casing delays the release of the material as the wire is immersed into the melt. This method of addition presents advantages such as higher repeatability and yield of cored material with respect to bulk additions. Experimental and numerical work has been performed by several authors on the subject of alloy additions, spherical and cylindrical geometries being mainly considered. Surprisingly this has not been the case for cored wire, where the reported experimental or numerical studies are scarce. This work presents a 1-D finite volume numerical model aimed for the simulation of the thermal phenomena which occurs when the wire is injected into a liquid metal bath. It is currently being used as a design tool for the conception of new types of cored wire. A parametric study on the effect of injection velocity and steel casing thickness for an Al cored wire immersed into a steel melt at 1863 K (1590 °C) is presented. The standard single casing wire is further compared against a wire with multiple casings. Numerical results show that over a certain range of injection velocities, the core contents' release is delayed in the multiple casing when compared to a single casing wire.

  15. Reducing heat stress under thermal insulation in protective clothing: microclimate cooling by a 'physiological' method.

    Science.gov (United States)

    Glitz, K J; Seibel, U; Rohde, U; Gorges, W; Witzki, A; Piekarski, C; Leyk, D

    2015-01-01

    Heat stress caused by protective clothing limits work time. Performance improvement of a microclimate cooling method that enhances evaporative and to a minor extent convective heat loss was tested. Ten male volunteers in protective overalls completed a work-rest schedule (130 min; treadmill: 3 × 30 min, 3 km/h, 5% incline) with or without an additional air-diffusing garment (climatic chamber: 25°C, 50% RH, 0.2 m/s wind). Heat loss was supported by ventilating the garment with dry air (600 l/min, ≪5% RH, 25°C). Ventilation leads (M ± SD, n = 10, ventilated vs. non-ventilated) to substantial strain reduction (max. HR: 123 ± 12 b/min vs. 149 ± 24 b/min) by thermal relief (max. core temperature: 37.8 ± 0.3°C vs. 38.4 ± 0.4°C, max. mean skin temperature: 34.7 ± 0.8°C vs. 37.1 ± 0.3°C) and offers essential extensions in performance and work time under thermal insulation. Heat stress caused by protective clothing limits work time. Performance can be improved by a microclimate cooling method that supports evaporative and to a minor extent convective heat loss. Sweat evaporation is the most effective thermoregulatory mechanism for heat dissipation and can be enhanced by insufflating dry air into clothing.

  16. Thermal nonlinear effect in high Q factor silicon-on-insulator microring resonator

    Science.gov (United States)

    Xiaogang, Tong; Jun, Liu; Chenyang, Xue

    2017-07-01

    In this paper, all-optical switching in silicon-on-insulator (SOI) serially coupled ring resonator based on thermal nonlinear effect is proposed. The radii of the silicon microring resonator are 10 μm. In experiment, firstly measured by single pump injection technology with vertical coupling surface grating coupler method, the highest notch of serially coupled ring resonator is 17 dB. The strong transverse light-confinement nature of the resonator induces nonlinear optical response with low pump power. Thermal nonlinear effect is achieved by controlling the power of the continuous-wave (CW) pump with very low tuning threshold (0.33 nm). And the slop of resonant wavelength as a function of injected pump is 220 pm/mw. Secondly, switching time measured by two pump injection technology is 3.01 μs and 1.03 μs, respectively. Which could be used in integrated photonic communication circuits based optical logic and slow-light structure.

  17. Response to fire, thermal insulation and acoustic performance of rigid polyurethane agglomerates with addition of natural fiber

    Directory of Open Access Journals (Sweden)

    Marcos Vinicius Rizzo

    2015-03-01

    Full Text Available This paper aims to reuse rigid polyurethane waste in the preparation of composites with the addition of banana fibers and cellulose in order to qualify the acoustic performance, thermal insulation and reaction to fire the material with the addition of 7% of polysulfone. Agglomerated with 100% of polyurethane and either with 20% of banana fiber or 20% of cellulose were characterized in the sound transmission loss, thermal conductivity and reaction to fire, take into account variations in the granulometry of the solid polyurethane and type of pressing. Natural fiber composites had lower thermal conductivity, higher acoustic insulation in medium frequencies and the addition of polysulfone delayed the total time of firing the material.

  18. Retrospective Analysis of NIST Standard Reference Material 1450, Fibrous Glass Board, for Thermal Insulation Measurements.

    Science.gov (United States)

    Zarr, Robert R; Heckert, N Alan; Leigh, Stefan D

    2014-01-01

    Thermal conductivity data acquired previously for the establishment of Standard Reference Material (SRM) 1450, Fibrous Glass Board, as well as subsequent renewals 1450a, 1450b, 1450c, and 1450d, are re-analyzed collectively and as individual data sets. Additional data sets for proto-1450 material lots are also included in the analysis. The data cover 36 years of activity by the National Institute of Standards and Technology (NIST) in developing and providing thermal insulation SRMs, specifically high-density molded fibrous-glass board, to the public. Collectively, the data sets cover two nominal thicknesses of 13 mm and 25 mm, bulk densities from 60 kg·m(-3) to 180 kg·m(-3), and mean temperatures from 100 K to 340 K. The analysis repetitively fits six models to the individual data sets. The most general form of the nested set of multilinear models used is given in the following equation: [Formula: see text]where λ(ρ,T) is the predicted thermal conductivity (W·m(-1)·K(-1)), ρ is the bulk density (kg·m(-3)), T is the mean temperature (K) and ai (for i = 1, 2, … 6) are the regression coefficients. The least squares fit results for each model across all data sets are analyzed using both graphical and analytic techniques. The prevailing generic model for the majority of data sets is the bilinear model in ρ and T. [Formula: see text] One data set supports the inclusion of a cubic temperature term and two data sets with low-temperature data support the inclusion of an exponential term in T to improve the model predictions. Physical interpretations of the model function terms are described. Recommendations for future renewals of SRM 1450 are provided. An Addendum provides historical background on the origin of this SRM and the influence of the SRM on external measurement programs.

  19. Survey and evaluation of available thermal insulation materials for use on solar heating and cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-01

    This is the final report of a survey and evaluation of insulation materials for use with components of solar heating and cooling systems. The survey was performed by mailing questionnaires to manufacturers of insulation materials and by conducting an extensive literature search to obtain data on relevant properties of various types of insulation materials. The study evaluated insulation materials for active and passive solar heating and cooling systems and for multifunction applications. Primary and secondary considerations for selecting insulation materials for various components of solar heating and cooling systems are presented.

  20. Thermal transport in topological-insulator-based superconducting hybrid structures with mixed singlet and triplet pairing states

    Science.gov (United States)

    Li, Hai; Zhao, Yuan Yuan

    2017-11-01

    In the framework of the Bogoliubov–de Gennes equation, we investigate the thermal transport properties in topological-insulator-based superconducting hybrid structures with mixed spin-singlet and spin-triplet pairing states, and emphasize the different manifestations of the spin-singlet and spin-triplet pairing states in the thermal transport signatures. It is revealed that the temperature-dependent differential thermal conductance strongly depends on the components of the pairing state, and the negative differential thermal conductance only occurs in the spin-singlet pairing state dominated regime. It is also found that the thermal conductance is profoundly sensitive to the components of the pairing state. In the spin-singlet pairing state controlled regime, the thermal conductance obviously oscillates with the phase difference and junction length. With increasing the proportion of the spin-triplet pairing state, the oscillating characteristic of the thermal conductance fades out distinctly. These results suggest an alternative route for distinguishing the components of pairing states in topological-insulator-based superconducting hybrid structures.

  1. Thermal implications of interactions between insulation, solar reflectance, and fur structure in the summer coats of diverse species of kangaroo.

    Science.gov (United States)

    Dawson, Terence J; Maloney, Shane K

    2017-04-01

    Not all of the solar radiation that impinges on a mammalian coat is absorbed and converted into thermal energy at the coat surface. Some is reflected back to the environment, while another portion is reflected further into the coat where it is absorbed and manifested as heat at differing levels. Substantial insulation in a coat limits the thermal impact at the skin of solar radiation, irrespective where in the coat it is absorbed. In coats with low insulation, the zone where solar radiation is absorbed may govern the consequent heat load on the skin (HL-SR). Thin summer furs of four species of kangaroo from differing climatic zones were used to determine how variation in insulation and in coat spectral and structural characteristics influence the HL-SR. Coat depth, structure, and solar reflectance varied between body regions, as well as between species. The modulation of solar radiation and resultant heat flows in these coats were measured at low (1 m s-1) and high (6 m s-1) wind speeds by mounting them on a heat flux transducer/temperature-controlled plate apparatus in a wind tunnel. A lamp with a spectrum similar to solar radiation was used as a proxy for the sun. We established that coat insulation was largely determined by coat depth at natural fur lie, despite large variations in fibre density, fibre diameter, and fur mass. Higher wind speed decreased coat insulation, but depth still determined the overall level. A multiple regression analysis that included coat depth (insulation), fibre diameter, fibre density, and solar reflectance was used to determine the best predictors of HL-SR. Only depth and reflectance had significant impacts and both factors had negative weights, so, as either insulation or reflectance increased, HL-SR declined, the larger impact coming from coat reflectance. This reverses the pattern observed in deep coats where insulation dominates over effects of reflectance. Across all coats, as insulation declined, reflectance increased. An

  2. Study of the Impact of Initial Moisture Content in Oil Impregnated Insulation Paper on Thermal Aging Rate of Condenser Bushing

    Directory of Open Access Journals (Sweden)

    Youyuan Wang

    2015-12-01

    Full Text Available This paper studied the impact of moisture on the correlated characteristics of the condenser bushings oil-paper insulation system. The oil-impregnated paper samples underwent accelerated thermal aging at 130 °C after preparation at different initial moisture contents (1%, 3%, 5% and 7%. All the samples were extracted periodically for the measurement of the moisture content, the degree of polymerization (DP and frequency domain dielectric spectroscopy (FDS. Next, the measurement results of samples were compared to the related research results of transformer oil-paper insulation, offering a theoretical basis of the parameter analysis. The obtained results show that the moisture fluctuation amplitude can reflect the different initial moisture contents of insulating paper and the mass ratio of oil and paper has little impact on the moisture content fluctuation pattern in oil-paper but has a great impact on moisture fluctuation amplitude; reduction of DP presents an accelerating trend with the increase of initial moisture content, and the aging rate of test samples is higher under low moisture content but lower under high moisture content compared to the insulation paper in transformers. Two obvious “deceleration zones” appeared in the dielectric spectrum with the decrease of frequency, and not only does the integral value of dielectric dissipation factor (tan δ reflect the aging degree, but it reflects the moisture content in solid insulation. These types of research in this paper can be applied to evaluate the condition of humidified insulation and the aging state of solid insulation for condenser bushings.

  3. Insulation and body temperature of prepubescent children wearing a thermal swimsuit during moderate-intensity water exercise.

    Science.gov (United States)

    Wakabayashi, Hitoshi; Kaneda, Koichi; Okura, Masashi; Nomura, Takeo

    2007-03-01

    This study investigated thermal swimsuits (TSS) effects on body temperature and thermal insulation of prepubescent children during moderate-intensity water exercise. Nine prepubescent children (11.0+/-0.7 yrs) were immersed in water (23 degrees C) and pedalled on an underwater cycle-ergometer for 30 min with TSS or normal swimsuits (NSS). The rectal temperature (Tre) was maintained slightly higher with TSS than with NSS. The total insulation (Itotal) was significantly higher with TSS. The DeltaTre, Deltamean body temperature (Tb), and tissue insulation (Itissue) in the NSS condition were correlated with % body fat, which indicated that the insulation layer of subjects with low body fat was thinner than that of obese subjects, and tended to decrease body temperature. Wearing TSS increased Itotal, thereby reducing heat loss from subjects' skin to the water. Consequently, subjects with TSS were able to maintain higher body temperatures. In addition, TSS is especially advantageous for subjects with low body fat to compensate for the smaller Itissue.

  4. Three-dimensional thermal aging and dimensional stability of cellular plastic insulation

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Youchen; Kokko, E. [VTT Building Technology, Espoo (Finland). Building Physics, Puilding Services and Fire Technology

    1996-12-31

    The requirement of producing environmental-friendly plastic foam results in the replacement of the traditional blowing agents, CFCs (chlorofluorocarbons), with zero ozone depletion potential (ODP) alternatives. The tool which is able to evaluate the quality of the new generation of plastic foams becomes practically important. A 3-dimensional (3-D) heat and mass (gases) transfer model with respect to rigid closed-cell cellular plastics has been carefully deduced and furnished based on our previous understanding of such problems. To solve the 3-D parabolic partial differential equations subject to the third type of boundary conditions, a modified alternative direction implicit (AD I) finite difference method was developed by using the natural laws. To predict the long-term dimensional stability of a plastic foam insulation in air, a simplified mechanical model has been presented. In addition, to closure the prediction of foam dimensional stability, we have deduced a general relationship between the elastic modulus (Young`s modulus) of a rigid closed-cell cellular plastic, E{sub f} and its density, {phi}{sub p}. In comparison to the published measurements and other two well-known E{sub f} - {phi}{sub p} models, it is found that our E{sub f} - up relationship gives better prediction and is valid over the entire rigid plastic foam density range. Thermal aging and average volume change of zero ODP foams with different facing will be addressed. In addition, the application of the model shows the effects of foam dimension and facing on its thermal aging and deformation. (orig.) (13 refs.)

  5. Experimental Study of Fire Hazards of Thermal-Insulation Material in Diesel Locomotive: Aluminum-Polyurethane.

    Science.gov (United States)

    Zhang, Taolin; Zhou, Xiaodong; Yang, Lizhong

    2016-03-05

    This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m² and 16.39 kW/m² for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both to predict the fire behaviors under different circumstances. The fire behavior of the materials was evaluated based on the flashover and the total heat release rate (HRR). The fire hazards levels were classified based on different experimental results. It was found that the fire resistance performance of aluminum-polyurethane is much better than that of pure-polyurethane under various external heat fluxes. The concentration of toxic pyrolysis volatiles generated from aluminum-polyurethane materials is much higher than that of pure polyurethane materials, especially when the heat flux is below 50 kW/m². The hazard index HI during peak width time was proposed based on the comprehensive impact of time and concentrations. The predicted HI in this model coincides with the existed N-gas and FED models which are generally used to evaluate the fire gas hazard in previous researches. The integrated model named HNF was proposed as well to estimate the fire hazards of materials by interpolation and weighted average calculation.

  6. Standard Test Method for Oxyacetylene Ablation Testing of Thermal Insulation Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the screening of ablative materials to determine the relative thermal insulation effectiveness when tested as a flat panel in an environment of a steady flow of hot gas provided by an oxyacetylene burner. 1.2 This test method should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard of materials, products, or assemblies under actual fire conditions. However, results of this test method may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limi...

  7. Experimental Study of Fire Hazards of Thermal-Insulation Material in Diesel Locomotive: Aluminum-Polyurethane

    Directory of Open Access Journals (Sweden)

    Taolin Zhang

    2016-03-01

    Full Text Available This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m2 and 16.39 kW/m2 for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both to predict the fire behaviors under different circumstances. The fire behavior of the materials was evaluated based on the flashover and the total heat release rate (HRR. The fire hazards levels were classified based on different experimental results. It was found that the fire resistance performance of aluminum-polyurethane is much better than that of pure-polyurethane under various external heat fluxes. The concentration of toxic pyrolysis volatiles generated from aluminum-polyurethane materials is much higher than that of pure polyurethane materials, especially when the heat flux is below 50 kW/m2. The hazard index HI during peak width time was proposed based on the comprehensive impact of time and concentrations. The predicted HI in this model coincides with the existed N-gas and FED models which are generally used to evaluate the fire gas hazard in previous researches. The integrated model named HNF was proposed as well to estimate the fire hazards of materials by interpolation and weighted average calculation.

  8. Multilayered thermal insulation formed of zirconia bonded layers of zirconia fibers and metal oxide fibers and method for making same

    Science.gov (United States)

    Wrenn, Jr., George E.; Holcombe, Jr., Cressie E.

    1988-01-01

    A multilayered thermal insulating composite is formed of a first layer of zirconia-bonded zirconia fibers for utilization near the hot phase or surface of a furnace or the like. A second layer of zirconia-bonded metal oxide fibers is attached to the zirconia fiber layer by a transition layer formed of intermingled zirconia fibers and metal oxide fibers. The thermal insulation is fabricated by vacuum molding with the layers being sequentially applied from aqueous solutions containing the fibers to a configured mandrel. A portion of the solution containing the fibers forming the first layer is intermixed with the solution containing the fibers of the second layer for forming the layer of mixed fibers. The two layers of fibers joined together by the transition layer are saturated with a solution of zirconium oxynitrate which provides a zirconia matrix for the composite when the fibers are sintered together at their nexi.

  9. Fabrication of Ohmic contact on semi-insulating 4H-SiC substrate by laser thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yue; Lu, Wu-yue; Wang, Tao; Chen, Zhi-zhan, E-mail: zzchen@shnu.edu.cn [Department of Physics, Shanghai Normal University, 100 Guilin Road, Shanghai 200234 (China)

    2016-06-14

    The Ni contact layer was deposited on semi-insulating 4H-SiC substrate by magnetron sputtering. The as-deposited samples were treated by rapid thermal annealing (RTA) and KrF excimer laser thermal annealing (LTA), respectively. The RTA annealed sample is rectifying while the LTA sample is Ohmic. The specific contact resistance (ρ{sub c}) is 1.97 × 10{sup −3} Ω·cm{sup 2}, which was determined by the circular transmission line model. High resolution transmission electron microscopy morphologies and selected area electron diffraction patterns demonstrate that the 3C-SiC transition zone is formed in the near-interface region of the SiC after the as-deposited sample is treated by LTA, which is responsible for the Ohmic contact formation in the semi-insulating 4H-SiC.

  10. Thermal insulation at high temperatures - possibilities for microporous construction materials; Waermedaemmung bei hohen Temperaturen - Moeglichkeiten mikroporoeser Baustoffe

    Energy Technology Data Exchange (ETDEWEB)

    Schulle, W.; Melzer, D. [TU Bergakademie Freiberg (Germany). Inst. fuer Silikattechnik

    1999-01-19

    The heat transfer of porous high-temperature materials is governed primarily by internal thermal conduction and internal thermal radiation which, for their part, depend on the porosity of the insulating material and its service temperature. A special technique - controlled hydrothermal synthesis - allows the manufacture of microporous heat-insulating materials that are also suitable for service temperatures of well over 1000 C. (orig.) [Deutsch] Der Waermetransport poroeser Hochtemperaturwerkstoffe wird vor allem durch innere Waermeleitung und innere Waermestrahlung bestimmt, die ihrerseits von der Porositaet des Daemmstoffes und seiner Einsatztemperatur abhaengen. Durch ein spezielles Verfahren - die gezielte Hydrothermalsynthese - koennen mikroporoese Waermedaemmstoffe hergestellt werden, die auch fuer Einstztemperaturen von weit ueber 1 000 C geeignet sind. (orig.)

  11. Effect of Thermal Bridges in Insulated Walls on Air-Conditioning Loads Using Whole Building Energy Analysis

    Directory of Open Access Journals (Sweden)

    Mohamed F. Zedan

    2016-06-01

    Full Text Available Thermal bridges in building walls are usually caused by mortar joints between insulated building blocks and by the presence of concrete columns and beams within the building envelope. These bridges create an easy path for heat transmission and therefore increase air-conditioning loads. In this study, the effects of mortar joints only on cooling and heating loads in a typical two-story villa in Riyadh are investigated using whole building energy analysis. All loads found in the villa, which broadly include ventilation, transmission, solar and internal loads, are considered with schedules based on local lifestyles. The thermal bridging effect of mortar joints is simulated by reducing wall thermal resistance by a percentage that depends on the bridges to wall area ratio (TB area ratio or Amj/Atot and the nominal thermal insulation thickness (Lins. These percentage reductions are obtained from a correlation developed by using a rigorous 2D dynamic model of heat transmission through walls with mortar joints. The reduction in thermal resistance is achieved through minor reductions in insulation thickness, thereby keeping the thermal mass of the wall essentially unchanged. Results indicate that yearly and monthly cooling loads increase almost linearly with the thermal bridge to wall area ratio. The increase in the villa’s yearly loads varies from about 3% for Amj/Atot = 0.02 to about 11% for Amj/Atot = 0.08. The monthly increase is not uniform over the year and reaches a maximum in August, where it ranges from 5% for Amj/Atot = 0.02 to 15% for Amj/Atot = 0.08. In winter, results show that yearly heating loads are generally very small compared to cooling loads and that heating is only needed in December, January and February, starting from late night to late morning. Monthly heating loads increase with the thermal bridge area ratio; however, the variation is not as linear as observed in cooling loads. The present results highlight the importance of

  12. Evaluation of the application of a thermal insulation system: in-situ comparison of seasonal and daily climatic fluctuations

    Czech Academy of Sciences Publication Activity Database

    Fořt, J.; Beran, Pavel; Konvalinka, P.; Pavlík, Z.; Černý, R.

    2017-01-01

    Roč. 57, č. 3 (2017), s. 159-166 ISSN 1210-2709 R&D Projects: GA ČR(CZ) GBP105/12/G059 Institutional support: RVO:68378297 Keywords : in-situ monitoring * temperature * relative humidity * thermal insulation * energy sustainability * seasonal fluctuations Subject RIV: JN - Civil Engineering OBOR OECD: Construction engineering, Municipal and structural engineering https://ojs.cvut.cz/ojs/index.php/ap/article/view/4087/4171

  13. Ultralight, highly thermally insulating and fire resistant aerogel by encapsulating cellulose nanofibers with two-dimensional MoS2.

    Science.gov (United States)

    Yang, Lei; Mukhopadhyay, Alolika; Jiao, Yucong; Yong, Qiang; Chen, Liao; Xing, Yingjie; Hamel, Jonathan; Zhu, Hongli

    2017-08-17

    Thermally insulating materials, made from earth-abundant and sustainable resources, are highly desirable in the sustainable construction of energy efficient buildings. Cellulose from wood has long been recognized for these characteristics. However, cellulose can be a flammability hazard, and for construction this has been addressed via chemical treatment such as that with halogen and/or phosphorus, which leads to further environmental concerns. Fortunately, the structure of cellulose lends itself well to chemical modification, giving great potential to explore interaction with other compounds. Thus, in this study, cellulose nanofibers (CNFs) were nano-wrapped with ultrathin 1T phase molybdenum disulfide (MoS2) nanosheets via chemical crosslinking, to produce an aerogel. Thermal and combustion characterization revealed highly desirable properties (thermal conductivity k = 28.09 mW m-1 K-1, insulation R value = 5.2, limit oxygen index (LOI) = 34.7%, total heat release = 0.4 MJ m-2). Vertical burning tests also demonstrated excellent fire retardant and self-extinguishing capabilities. Raman spectra further revealed that MoS2 remained unscathed after 30 seconds of burning in a 1300 °C butane flame. Considering the inherently low density of this material, there is significant opportunity for its usage in a number of insulating applications demanding specific fire resistance properties.

  14. Determination of Thermal Transmittance of Insulated Double Low-E Glazing Panel Using Portable Uglass Measuring Technique

    Science.gov (United States)

    Kim, Inkoo; Frenzl, Alexander; Kim, Taehan; Min, Steven; Blumm, Jürgen

    2018-01-01

    Windows are regarded as the primary object of energy efficiency in buildings because window is one of the major energy loss areas in building construction. Existing methods were not field measurements and were not enough to get the correct thermal transmittance. We used portable Ug measuring device on field and measured the thermal transmittance with low-E coated and uncoated double glazing panels in existing houses, apartments and buildings. In addition, we prepared four test benches and compared the insulation performance according to the construction conditions. In results, the insulation performance of double glazing panel with low-E coating is up to about 41 % higher than uncoated panel due to low-E coating inside and the glazing panel filled with about 90 % of argon gas decrease about 0.15 W \\cdot m^{-2} \\cdot K^{-1} than glazing panel filled with air gas. The measured results were compared with the theoretically calculated results according to DIN EN 673 to confirm the reliability of the analytical results. In this study, portable NETZSCH Uglass is used to increase the accuracy of calculation of thermal transmittance with various double and triple glazing panels. The paper analyzes the insulation performance of the double glazing panels in accordance with the construction conditions.

  15. The determination of values of the specific heat capacity of the selected thermal insulation materials used in track bed structure

    Directory of Open Access Journals (Sweden)

    Dobeš Peter

    2017-01-01

    Full Text Available The report concentrates on the determination of the specific heat capacity of the selected thermal insulation materials (liapor, styrodur, foam concrete. The aim of the report is to gain the necessary input parameters for the numerical modelling of the temperature changes of various track bed structures of the railway line where a part or, if appropriate, the whole protective layer is replaced by the material with better thermal insulation properties. There are described the methods for stating the specific heat capacity as well as the calibration of the calorimeter for stating of the calorimetric constant in the introduction of the report. The parameters needed for calculation of the specific heat capacity of the selected thermal insulation materials are characterized in the second part of the report. There are also introduced the laboratory stated values of the parameter in question. The comparison of the values stated by the laboratory measurements with the values introduced in the technical data sheets from their producers (or if appropriate gained from the foreign sources is made in the conclusion of the report.

  16. Performance Characterisation of a Hybrid Flat-Plate Vacuum Insulated Photovoltaic/Thermal Solar Power Module in Subtropical Climate

    Directory of Open Access Journals (Sweden)

    Andrew Y. A. Oyieke

    2016-01-01

    Full Text Available A flat-plate Vacuum Insulated Photovoltaic and Thermal (VIPV/T system has been thermodynamically simulated and experimentally evaluated to assess the thermal and electrical performance as well as energy conversion efficiencies under a subtropical climate. A simulation model made of specified components is developed in Transient Systems (TRNSYS environment into which numerical energy balance equations are implemented. The influence of vacuum insulation on the system’s electrical and thermal yields has been evaluated using temperatures, current, voltage, and power flows over daily and annual cycles under local meteorological conditions. The results from an experiment conducted under steady-state conditions in Durban, South Africa, are compared with the simulation based on the actual daily weather data. The VIPV/T has shown improved overall and thermal efficiencies of 9.5% and 16.8%, respectively, while electrical efficiency marginally reduced by 0.02% compared to the conventional PV/T. The simulated annual overall efficiency of 29% (i.e., 18% thermal and 11% electrical has been realised, in addition to the solar fraction, overall exergy, and primary energy saving efficiencies of 39%, 29%, and 27%, respectively.

  17. Aligned Graphene Oxide Nanofillers: An Approach to Prepare Highly Thermally Conductive and Electrically Insulative Transparent Polymer Composites

    Directory of Open Access Journals (Sweden)

    Genlian Lin

    2015-01-01

    Full Text Available Graphene oxide (GO/polyvinyl alcohol composites with extremely high in-plane thermal conductivities are prepared by a simple tape casting process using water as process solvent. The in-plane thermal conductivity of the composite can reach 17.61 W/mK at only 0.1 wt% GO loading, which is close to that of fully dense alumina. The excellent thermal conducting ability, the unique two-dimensional morphology, and the all-wet handling of the GO fillers as well as the high orientation of the fillers in the polymer matrix all contribute to the high thermal conductivities achieved. Meanwhile, the composites show good electrical insulation property and decent transparency.

  18. Low conductive support for thermal insulation of a sample holder of a variable temperature scanning tunneling microscope.

    Science.gov (United States)

    Hanzelka, Pavel; Vonka, Jakub; Musilova, Vera

    2013-08-01

    We have designed a supporting system to fix a sample holder of a scanning tunneling microscope in an UHV chamber at room temperature. The microscope will operate down to a temperature of 20 K. Low thermal conductance, high mechanical stiffness, and small dimensions are the main features of the supporting system. Three sets of four glass balls placed in vertices of a tetrahedron are used for thermal insulation based on small contact areas between the glass balls. We have analyzed the thermal conductivity of the contacts between the balls mutually and between a ball and a metallic plate while the results have been applied to the entire support. The calculation based on a simple model of the setup has been verified with some experimental measurements. In comparison with other feasible supporting structures, the designed support has the lowest thermal conductance.

  19. Colloquium 3: Thermal insulation materials in construction and in high-temperature plants. Lectures; Kolloquium 3: Waermedaemmstoffe im Bauwesen und in Hochtemperaturanlagen. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, E.; Gross, U.; Walter, G. [comps.

    1999-07-01

    Colloquium 3, ''Thermal insulation materials in construction and in high-temperature plants'' focused, for one thing, on the inter-relationships between the development of thermal insulation materials for construction and high-temperature applications and the development of processes and plants and, for another, on the standards of and amendments to the thermal protection ordinance. Calcium silicate and Silcapor as a thermal protection material and a high-temperature thermal insulant, respectively, are dealt with inter alia. The use of thermal insulants in industrial furnaces and different methods for measuring thermal conductivity are described. Further topics are the elements of the energy conservation ordinance being drafted, and thermal-insulation construction materials such as bricks and foam mortar. Ten papers are individually listed in the Energy database. (orig.) [German] Im Mittelpunkt des Kolloquium 3 ''Waermedaemmstoffe im Bauwesen und in Hochtemperaturanlagen'' stehen die wechselseitigen Zusammenhaenge zwischen der Entwicklung von Waermedaemmstoffen fuer das Bauwesen und die Hochtemperaturanwendung einerseits und der Prozess-und Anlagenentwicklung anderseits sowie die Normung und die Novellierung der Waermeschutzverordnung. Es wird u.a. auf den Waermedaemmstoff Calciumsilicat eingegangen ebensowie auf Silcapor als Hochtemperaturd ammstoff. Der Einsatz von Waermedaemmstoffen in Industrieoefen sowie die unterschiedlichen Messmethoden der Waermeleitfaehigkeit werden beschrieben. Weitere Themen sind die Grundlagen der kuenftigen Energiesparverordnung sowie waermedaemmende Baustoffe wie Ziegel und Porenbeton. Fuer die Datenbank Energy wurden zehn Arbeiten separat aufgenommen.

  20. Influence of Three Dynamic Predictive Clothing Insulation Models on Building Energy Use, HVAC Sizing and Thermal Comfort

    Directory of Open Access Journals (Sweden)

    Kwang Ho Lee

    2014-03-01

    Full Text Available In building energy simulation, indoor thermal comfort condition, energy use and equipment size are typically calculated based on the assumption that the clothing insulation is equal to a constant value of 0.5 clo during the cooling season and 1.0 clo during the heating season. The assumption is not reflected in practice and thus it may lead to errors. In reality, occupants frequently adjust their clothing depending on the thermal conditions, as opposed to the assumption of constant clothing values above, indicating that the clothing insulation variation should be captured in building simulation software to obtain more reliable and accurate results. In this study, the impact of three newly developed dynamic clothing insulation models on the building simulation is quantitatively assessed using the detailed whole-building energy simulation program, EnergyPlus version 6.0. The results showed that when the heating ventilation and air conditioning system (HVAC is controlled based on indoor temperature the dynamic clothing models do not affect indoor operative temperatures, energy consumption and equipment sizing. When the HVAC is controlled based on the PMV model the use of a fixed clothing insulation during the cooling (0.5 clo and heating (1.0 clo season leads to the incorrect estimation of the indoor operative temperatures, energy consumption and equipment sizing. The dynamic clothing models significantly (p < 0.0001 improve the ability of energy simulation tools to assess thermal comfort. The authors recommend that the dynamic clothing models should be implemented in dynamic building energy simulation software such as EnergyPlus.

  1. Improving Thermal Insulation Properties for Prefabricated Wall Components Made Of Lightweight Aggregate Concrete with Open Structure

    Science.gov (United States)

    Abramski, Marcin

    2017-10-01

    Porous concrete is commonly used in civil engineering due to its good thermal insulation properties in comparison with normal concrete and high compression strength in comparison with other building materials. Reducing of the concrete density can be obviously obtained by using lightweight aggregate (e.g. pumice). The concrete density can be further minimized by using specially graded coarse aggregate and little-to-no fine aggregates. In this way a large number of air voids arise. The aggregate particles are coated by a cement paste and bonded together with it just in contact points. Such an extremely porous concrete, called ‘lightweight aggregate concrete with open structure’ (LAC), is used in some German plants to produce prefabricated wall components. They are used mainly in hall buildings, e.g. supermarkets. The need of improving thermal insulation properties was an inspiration for the prefabrication plant managers, engineers and a scientific staff of the Technical University of Kaiserslautern / Germany to realise an interesting project. Its aim was to reduce the heat transfer coefficient for the wall components. Three different wall structure types were designed and compared in full-scale laboratory tests with originally produced wall components in terms of load-carrying capacity and stiffness. The load was applied perpendicularly to the wall plane. As the components are not originally used for load-bearing walls, but for curtain walls only, the wind load is the main load for them. The wall components were tested in horizontal position and the load was applied vertically. Totally twelve wall components 8.00 × 2.00 × 0.25m (three for every series) were produced in the prefabrication plant and tested in the University of Kaiserslautern laboratory. The designed and tested components differed from each other in the amount of expanded polystyrene (EPS), which was placed in the plant inside the wall structure. The minimal amount of it was designed in the

  2. Contribution study to the thermal insulation of the builders in the desert regions of exploiting gypsum fiber reinforced palm

    Science.gov (United States)

    Hafsi, Fouad; Kriker, Abdelouahed; Abani, Said

    2017-02-01

    Algerian Desert areas were characterized by very hot climate in summer and very cold in winter. The most widely used building material in these areas are concrete, mortar cement, which has a bad thermal insulation, causing a significant increase in cooling and heating costs; in order to avoid this problem it become a must to replace these materials with a good thermal isolation material and lower production cost. This work is part of the evaluation of local materials by improving their performance in the field of thermal insulation, which is considered a first step in the development of new local materials to be used in the construction field, the material used in this study is the gypsum reinforced with date palm fiber. In fact, Algeria has extraordinary resources in natural fibers (from Palm, Abaca, Hemp…) but without any large valorization in building materials. The aim of this work is then to characterization of those date palm fibers in new building materials approved for use in the construction of buildings in the desert areas. The date palm fibers were added to samples of the gypsum material in the form of cutting layers at different volume fraction, so as to determine the extent of their impact in the improvement of the thermal performance. The results were very satisfactory, reaching improvement rate of 16% for samples gypsum reinforced with single cut fiber form, and 32% of the samples reinforced with fiber in the form of layers.

  3. The roles of thermal insulation and heat storage in the energy performance of the wall materials: a simulation study.

    Science.gov (United States)

    Long, Linshuang; Ye, Hong

    2016-04-07

    A high-performance envelope is the prerequisite and foundation to a zero energy building. The thermal conductivity and volumetric heat capacity of a wall are two thermophysical properties that strongly influence the energy performance. Although many case studies have been performed, the results failed to give a big picture of the roles of these properties in the energy performance of an active building. In this work, a traversal study on the energy performance of a standard room with all potential wall materials was performed for the first time. It was revealed that both heat storage materials and insulation materials are suitable for external walls. However, the importances of those materials are distinct in different situations: the heat storage plays a primary role when the thermal conductivity of the material is relatively high, but the effect of the thermal insulation is dominant when the conductivity is relatively low. Regarding internal walls, they are less significant to the energy performance than the external ones, and they need exclusively the heat storage materials with a high thermal conductivity. These requirements for materials are consistent under various climate conditions. This study may provide a roadmap for the material scientists interested in developing high-performance wall materials.

  4. EVALUATION OF THE APPLICATION OF A THERMAL INSULATION SYSTEM: IN-SITU COMPARISSON OF SEASONAL AND DAILY CLIMATIC FLUCTUATIONS

    Directory of Open Access Journals (Sweden)

    Jan Fořt

    2017-06-01

    Full Text Available The current outdated state of many institutional and administrative buildings in the EU region poses a significant burden from the energy sustainability point of view. According to the contemporary EU requirements on the energy efficiency of buildings maintenance, an evaluation of performed improvements is essential for the assessment of expended investments. This paper describes the effect of building envelope reconstruction works consisting in the installation of a thermal insulation system. Here, a long-term continuous monitoring is used for the extensive assessment of the seasonal and daily temperature and relative humidity fluctuations. The obtained results include temperature and relative humidity profiles in the wall cross-section as a response to the changing exterior climatic conditions. The analysis of measured data reveals substantial improvements in thermal stability of the analyzed wall during temperature peaks. While the indoor temperatures exceeding 28 °C are recorded during summer before application of the thermal insulation layer, the thermal stability of the indoor environment is distinctly upgraded after performed improvements. Based on the complex long-term monitoring, a relevant experience is gained for the future work on energy sustainability and fulfilment of the EU directives.

  5. Thermal insulation of buildings classified as historical monuments with particular emphasis on moisture protection; Hygrisch motivierter Waermeschutz von Altbauten mit denkmalgeschuetzter Fassade

    Energy Technology Data Exchange (ETDEWEB)

    Haeupl, P.; Martin, R.; Fechner, H.; Neue, J. [Technische Univ. Dresden (Germany). Inst. fuer Bauklimatik

    1997-12-31

    Buildings classified as historical must not be fitted with external thermal insulation elements. This project investigates a `gentle` type of an internal thermal insulation system with capillary activity permitting diffusion. A 120-year-old building with a historical house-front was thermally insulated at the inside using a 30-millimetre-thick calcium silicate plate with embedded fibres having capillary activity. The paper discusses the heat flow densities between the internal thermal insulation and the original part of the structure. Moisture fields in the wall in the case of mineral wool insulation and internal thermal insulation with capillary activity are compared. Moisture distribution in the area of the juncture between masonry and window and in the area of the beam head is shown by means of diagrams. (MSK) [Deutsch] Weil bei denkmalgeschuetzten Fassanden ein aussen angebrachtes Thermoverbundsystem nicht moeglich ist, wird in diesem Projekt eine sanfte kapillaraktive, diffusionsoffene Innendaemmung untersucht. Als Referenzobjekt wurde ein etwa 120 Jahre altes Gruenderzeithaus mit denkmalgeschuetzter Fassade mit einer 30mm dicken faserdotierten kapillaraktiven Calciumsilikatplatte innenseitig gedaemmt. Im Folgenden werden die Waermestromdichten zwischen Innendaemmung und Altkonstruktion erlaeutert. Die Feuchtefelder in der Wand bei Mineralwolleindaemmung und bei kapillaraktiver Innendaemmung werden verglichen. Die Feuchteverteilung im Bereich des Fenteranschlusses und des Balkenkopfes wird in Diagrammen dargestellt.

  6. Thermal Stability of Modified Insulation Paper Cellulose Based on Molecular Dynamics Simulation

    National Research Council Canada - National Science Library

    Chao Tang; Song Zhang; Qian Wang; Xiaobo Wang; Jian Hao

    2017-01-01

    In this paper, polysiloxane is used to modify insulation paper cellulose, and molecular dynamics methods are used to evaluate the glass transition temperature and mechanical properties of the paper...

  7. Integrated MLI: Advanced Thermal Insulation Using Micro-Molding Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current Multilayer Insulation (MLI) technology is over 50 years old, and is typically comprised of 10 to 120 layers of metalized polymer films separated by polyester...

  8. Thermal Characteristics of Multilayer Insulation Materials for Flexible Thin-Film Solar Cell Array of Stratospheric Airship

    Directory of Open Access Journals (Sweden)

    Kangwen Sun

    2014-01-01

    Full Text Available Flexible thin-film solar cell is an efficient energy system on the surface of stratospheric airship for utilizing the solar energy. In order to ensure the normal operation of airship platform, the thermal control problem between the flexible thin-film solar cell and the airship envelope should be properly resolved. In this paper, a multilayer insulation material (MLI is developed first, and low temperature environment test is carried out to verify the insulation effect of MLI. Then, a thermal heat transfer model of flexible thin-film solar cell and MLI is proposed, and the equivalent thermal conductivity coefficients of flexible thin-film solar cell and Nomex honeycomb are calculated based on the environment test and the temperature profile of flexible thin-film solar cell versus each layer of MLI. Finally, FLUENT is used for modeling and simulation analysis on the flexible thin-film solar cell and MLI, and the simulation results agree well with the experimental data, which validate the correctness of the proposed heat transfer model of MLI. In some way, our study can provide helpful support for further engineering applications of flexible thin-film solar cell.

  9. Resistance noise spectroscopy across the thermally and electrically driven metal-insulator transitions in VO2 nanobeams

    Science.gov (United States)

    Alsaqqa, Ali; Kilcoyne, Colin; Singh, Sujay; Horrocks, Gregory; Marley, Peter; Banerjee, Sarbajit; Sambandamurthy, G.

    Vanadium dioxide (VO2) is a strongly correlated material that exhibits a sharp thermally driven metal-insulator transition at Tc ~ 340 K. The transition can also be triggered by a DC voltage in the insulating phase with a threshold (Vth) behavior. The mechanisms behind these transitions are hotly discussed and resistance noise spectroscopy is a suitable tool to delineate different transport mechanisms in correlated systems. We present results from a systematic study of the low frequency (1 mHz noise behavior in VO2 nanobeams across the thermally and electrically driven transitions. In the thermal transition, the power spectral density (PSD) of the resistance noise is unchanged as we approach Tc from 300 K and an abrupt drop in the magnitude is seen above Tc and it remains unchanged till 400 K. However, the noise behavior in the electrically driven case is distinctly different: as the voltage is ramped from zero, the PSD gradually increases by an order of magnitude before reaching Vth and an abrupt increase is seen at Vth. The noise magnitude decreases above Vth, approaching the V = 0 value. The individual roles of percolation, Joule heating and signatures of correlated behavior will be discussed. This work is supported by NSF DMR 0847324.

  10. Fabrication of Ge-on-insulator wafers by Smart-CutTM with thermal management for undamaged donor Ge wafers

    Science.gov (United States)

    Kim, Munho; Cho, Sang June; Jayeshbhai Dave, Yash; Mi, Hongyi; Mikael, Solomon; Seo, Jung-Hun; Yoon, Jung U.; Ma, Zhenqiang

    2018-01-01

    Newly engineered substrates consisting of semiconductor-on-insulator are gaining much attention as starting materials for the subsequent transfer of semiconductor nanomembranes via selective etching of the insulating layer. Germanium-on-insulator (GeOI) substrates are critically important because of the versatile applications of Ge nanomembranes (Ge NMs) toward electronic and optoelectronic devices. Among various fabrication techniques, the Smart-CutTM technique is more attractive than other methods because a high temperature annealing process can be avoided. Another advantage of Smart-CutTM is the reusability of the donor Ge wafer. However, it is very difficult to realize an undamaged Ge wafer because there exists a large mismatch in the coefficient of thermal expansion among the layers. Although an undamaged donor Ge wafer is a prerequisite for its reuse, research related to this issue has not yet been reported. Here we report the fabrication of 4-inch GeOI substrates using the direct wafer bonding and Smart-CutTM process with a low thermal budget. In addition, a thermo-mechanical simulation of GeOI was performed by COMSOL to analyze induced thermal stress in each layer of GeOI. Crack-free donor Ge wafers were obtained by annealing at 250 °C for 10 h. Raman spectroscopy and x-ray diffraction (XRD) indicated similarly favorable crystalline quality of the Ge layer in GeOI compared to that of bulk Ge. In addition, Ge p-n diodes using transferred Ge NM indicate a clear rectifying behavior with an on and off current ratio of 500 at ±1 V. This demonstration offers great promise for high performance transferrable Ge NM-based device applications.

  11. Mathematical Modeling Of Heat Transfer in the System "The Object Of Heating – Thermal Insulation Layer – The External Environment" and Microclimate Parameters of Industrial Premises

    OpenAIRE

    Ulchiekov, Mikhail

    2016-01-01

    This paper been solved the task of thermal conductivity for the system “the object of heating – thermal insulation layer – the external environment.” The impact of the main groups of factors on the temperature of heating the object surface has been shown.

  12. Thermal conductivity: recent developments on insulating and new materials; La conductivite thermique: developpements recents sur les isolants et les materiaux nouveaux

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This workshop organized by the thermo-kinetics section of the French society of thermal engineers deals with recent developments concerning insulating, dielectric and composite materials. The seven papers presented during this workshop concern the methods and results of thermal conductivity measurements performed in these materials and the possible applications of these materials in aerospace industry (carbon foams, ceramic-based composite materials), civil engineering (glazing materials, aerogels), power electronics (dielectric thin films, ceramics), and in other industries (heat resistant and thermal insulating materials). (J.S.)

  13. Determination of the Thermal Insulation for the Model Building Approach and the Global Effects in Turkey

    Directory of Open Access Journals (Sweden)

    Cenk Onan

    2014-08-01

    Full Text Available One of the most important considerations to be considered in the design of energy efficient buildings is the thickness of the insulation to be applied to the building. In this study the existing building stock in Turkey has been investigated depending on parameters such as the height and the area. A model building has been created covering all of these buildings. Fuel emission reduction of combustion system was calculated in the case of insulation applied to this model building. Heat loss of the existing building stock and exhaust emissions and the contribution to the country's economy with the model building methodology are also determined. The results show that the optimum insulation thicknesses vary between 3.21 and 7.12 cm, the energy savings vary between 9.23 US$/m2 and43.95 US$/m2, and the payback periods vary between 1 and 8.8 years depending on the regions. As a result of the study when the optimum insulation thickness is applied in the model building, the total energy savings for the country are calculated to be 41.7 billion US$. And also total CO2 emissions for the country are calculated to be 57.2 billion kg CO2 per year after insulation.

  14. Insulation effect on thermal stability of Coated Conductors wires in liquid nitrogen

    Science.gov (United States)

    Rubeli, Thomas; Dutoit, Bertrand; Martynova, Irina; Makarevich, Artem; Molodyk, Alexander; Samoilenkov, Sergey

    2017-02-01

    Superconducting wires are not perfectly homogeneous in term of critical current as well as stabilization. In resistive fault current limiter applications this could lead to hot spots if the fault current is only slightly above the nominal current of the device. Increasing stabilization by using thicker silver coating for example may prevent this problem but this method implies longer wire length to maintain the same impedance during a fault. Very efficient cooling in another way to prevent hot spots, this can be achieved in nucleate boiling regime. Optimal insulation can be used to prevent film boiling regime, staying in nucleate boiling regime in a much broader temperature range. In this work a novel technique is used to monitor in real time the temperature of the wire during the quench. Using this method several increasing insulation thicknesses are tested, measuring for each the heat exchange rate to the nitrogen bath. Exchange rate measurements are made in quasistatic regime and during the re-cooling of the wire. SuperOx wires provided with different insulation thicknesses exhibit an excellent stability, far above a bare wire. On the other side, for very thick insulations the stability gain is lost. Re-cooling speeds dependency on insulation thicknesses is measured too.

  15. Parallel and serial methods of calculating thermal insulation in European manikin standards.

    Science.gov (United States)

    Kuklane, Kalev; Gao, Chuansi; Wang, Faming; Holmér, Ingvar

    2012-01-01

    Standard No. EN 15831:2004 provides 2 methods of calculating insulation: parallel and serial. The parallel method is similar to the global one defined in Standard No. ISO 9920:2007. Standards No. EN 342:2004, EN 14058:2004 and EN 13537:2002 refer to the methods defined in Standard No. EN ISO 15831:2004 for testing cold protective clothing or equipment. However, it is necessary to consider several issues, e.g., referring to measuring human subjects, when using the serial method. With one zone, there is no serial-parallel issue as the results are the same, while more zones increase the difference in insulation value between the methods. If insulation is evenly distributed, differences between the serial and parallel method are relatively small and proportional. However, with more insulation layers overlapping in heavy cold protective ensembles, the serial method produces higher insulation values than the parallel one and human studies. Therefore, the parallel method is recommended for standard testing.

  16. Influence of germanium on thermal dewetting and agglomeration of the silicon template layer in thin silicon-on-insulator

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, P P; Yang, B; Rugheimer, P P; Roberts, M M; Savage, D E; Lagally, M G [University of Wisconsin, Madison, WI 53706 (United States); Liu Feng, E-mail: lagally@engr.wisc.ed [University of Utah, Salt Lake City, UT 84112 (United States)

    2009-09-07

    We investigate the influence of heteroepitaxially grown Ge on the thermal dewetting and agglomeration of the Si(0 0 1) template layer in ultrathin silicon-on-insulator (SOI). We show that increasing Ge coverage gradually destroys the long-range ordering of 3D nanocrystals along the (1 3 0) directions and the 3D nanocrystal shape anisotropy that are observed in the dewetting and agglomeration of pure SOI(0 0 1). The results are qualitatively explained by Ge-induced bond weakening and decreased surface energy anisotropy. Ge lowers the dewetting and agglomeration temperature to as low as 700 {sup 0}C.

  17. MHD stagnation point flow toward a linearly-stretching thermally-insulated sheet with induced magnetic field

    CERN Document Server

    El-Mistikawy, Tarek M A

    2016-01-01

    The equations governing the magnetohydrodynamic stagnation point flow toward a non-conducting, thermally insulated, nonporous, linearly stretching sheet are cast in a self similar form. Consistent boundary conditions on the velocity, magnetic field and temperature are invoked. The flow problem involves three parameters- the magnetic Prandtl number, the magnetic interaction number, and the ratio of the stretching rate to the strength of the stagnation point flow. The energy equation includes viscous dissipation and Joule heating, and introduces the Prandtl number as a fourth parameter. Numerical solutions are obtained and sample results are presented.

  18. Calculation of clothing insulation by serial and parallel methods: effects on clothing choice by IREQ and thermal responses in the cold.

    Science.gov (United States)

    Kuklane, Kalev; Gao, Chuansi; Holmér, Ingvar; Giedraityte, Lina; Bröde, Peter; Candas, Victor; den Hartog, Emiel; Meinander, Harriet; Richards, Mark; Havenith, George

    2007-01-01

    Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic rate; (c) to evaluate the movement and wind correction of clothing insulation values. Tests were carried out on 8 subjects. The results showed the possibility of incorporating the effect of increases in metabolic rate values due to thick cold protective clothing into the IREQ model. Using the higher thermal insulation value from the serial method in the IREQ prediction, would lead to unacceptable cooling of the users. Thus, only the parallel insulation calculation method in EN 342:2004 should be used. The wind and motion correction equation (No. 2) gave realistic values for total resultant insulation; dynamic testing according to EN 342:2004 may be omitted.

  19. Insulation materials. Cellulose fiber and Expanded polystyrene Insulations

    OpenAIRE

    Viladot Bel, Cèlia

    2017-01-01

    The main role of thermal insulation materials in a building envelope are to prevent heat loss and provide thermal comfort for a building's interior. The factor that characterizes an insulation material's effectiveness is its thermal conductivity λ (measured in W/mK). The lower a material's thermal conductivity, the more effective it is as an insulator. Traditional insulation materials include glass fibre, stone wool, expanded polystyrene, and polyurethane foam. While these materials are effic...

  20. Insulation materials. Cellulose fiber and expanded polystyrene insulations

    OpenAIRE

    Viladot Bel, Cèlia

    2017-01-01

    The main role of thermal insulation materials in a building envelope are to prevent heat loss and provide thermal comfort for a building's interior. The factor that characterizes an insulation material's effectiveness is its thermal conductivity λ (measured in W/mK). The lower a material's thermal conductivity, the more effective it is as an insulator. Traditional insulation materials include glass fibre, stone wool, expanded polystyrene, and polyurethane foam. While these materials are effic...

  1. California residential energy standards: problems and recommendations relating to implementation, enforcement, and design. [Thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    1977-08-01

    Documents relevant to the development and implementation of the California energy insulation standards for new residential buildings were evaluated and a survey was conducted to determine problems encountered in the implementation, enforcement, and design aspects of the standards. The impact of the standards on enforcement agencies, designers, builders and developers, manufacturers and suppliers, consumers, and the building process in general is summarized. The impact on construction costs and energy savings varies considerably because of the wide variation in prior insulation practices and climatic conditions in California. The report concludes with a series of recommendations covering all levels of government and the building process. (MCW)

  2. Automotive Insulation

    Science.gov (United States)

    1997-01-01

    Under a Space Act Agreement between Boeing North America and BSR Products, Space Shuttle Thermal Protection System (TPS) materials are now used to insulate race cars. BSR has created special TPS blanket insulation kits for use on autos that take part in NASCAR events, and other race cars through its nationwide catalog distribution system. Temperatures inside a race car's cockpit can soar to a sweltering 140 to 160 degrees, with the extreme heat coming through the engine firewall, transmission tunnel, and floor. It is common for NASCAR drivers to endure blisters and burns due to the excessive heat. Tests on a car insulated with the TPS material showed a temperature drop of some 50 degrees in the driver's cockpit. BSR-TPS Products, Inc. now manufactures insulation kits for distribution to race car teams around the world.

  3. Coupled magneto-thermal field computation in three-phase gas insulated cables. Pt. 2. Calculation of ampacity and losses

    Energy Technology Data Exchange (ETDEWEB)

    Hatziathanassiou, V. [Dept. of Electrical Engineering, Section of Electrical Energy, Aristotelian Univ. of Thessaloniki (Greece); Labridis, D. [Dept. of Electrical Engineering, Section of Electrical Energy, Aristotelian Univ. of Thessaloniki (Greece)

    1993-12-31

    The calculation of ampacity and losses of three-phases gas insulated cables based on the FEM formulation which was developed in Part 1 is presented. Limitations of the common mesh for both problems (electromagnetic and thermal) are also presented. Comparisons with existing calculations are made. Results concerning the sensitivity of cable ampacity and losses to variations of design and environmental parameters (burial depth, ambient temperature, soil thermal conductivity, cable emissivities, heat transfer coefficient, sheath radius) are finally presented. (orig.) [Deutsch] Basierend auf dem in Teil 1 beschriebenen Loesungsansatz mit der Finite-Elemente-Methode wird die Berechnung der Stromtragefaehigkeit und der Verluste eines dreiphasigen gasisolierten Kabels angegeben. Dabei wird auch auf die Grenzen bei Verwendung eines fuer beide Probleme (elektromagnetisches und thermisches Feld) gemeinsamen Gitternetzes eingegangen und ein Vergleich mit existierenden Berechnungsverfahren gemacht. Abschliessend werden Ergebnisse bezueglich der Abhaengigkeit der Stromtragefaehigkeit und der Verluste von Konstruktions- und Umgebungsparametern (Verlegetiefe, Umgebungstemperatur, Waermeleitfaehigkeit des Bodens, Waermeabstrahlung des Kabels, Waermeuebergangskoeffizient, Mantelradius) vorgestellt. (orig.)

  4. Strain and thermally induced magnetic dynamics and spin current in magnetic insulators subject to transient optical grating

    Science.gov (United States)

    Wang, Xi-Guang; Chotorlishvili, Levan; Berakdar, Jamal

    2017-07-01

    We analyze the magnetic dynamics and particularlythe spin current in an open-circuit ferromagnetic insulator irradiated by two intense, phase-locked laser pulses. The interference of the laser beams generates a transient optical grating and a transient spatio-temporal temperature distribution. Both effects lead to elastic and heat waves at the surface and into the bulk of the sample. The strain induced spin current as well as the thermally induced magnonic spin current are evaluated numerically on the basis of micromagnetic simulations using solutions of the heat equation. We observe that the thermo-elastically induced magnonic spin current propagates on a distance larger than the characteristic size of thermal profile, an effect useful for applications in remote detection of spin caloritronics phenomena. Our findings point out that exploiting strain adds a new twist to heat-assisted magnetic switching and spin-current generation for spintronic applications.

  5. Reliability and effective thermal conductivity of three metallic-ceramic composite insulating coatings on cooled hydrogen-oxygen rockets

    Science.gov (United States)

    Price, H. G., Jr.; Schacht, R. L.; Quentmeyer, R. J.

    1973-01-01

    An experimental investigation of the structural integrity and effective thermal conductivity of three metallic-ceramic composite coatings was conducted. These coatings were plasma sprayed onto the combustion side of water-cooled, 12.7-centimeter throat diameter, hydrogen-oxygen rocket thrust chambers operating at 2.07 to 4.14 meganewtons per square meter chamber pressure. The metallic-ceramic composites functioned for six to 17 cycles and for as long as 213 seconds of rocket operations and could have probably provided their insulating properties for many additional cycles. The effective thermal conductivity of all the coatings was in the range of 0.7472 to 4.483 w/(m)(K), which makes the coatings a very effective thermal barrier. Photomicrographic studies of cross-sectioned coolant tubes seem to indicate that the effective thermal conductivity of the coatings is controlled by contact resistance between the particles, as a result of the spraying process, and not the thermal conductivity of the bulk materials.

  6. Life cycle assessment of hemp cultivation and use of hemp-based thermal insulator materials in buildings.

    Science.gov (United States)

    Zampori, Luca; Dotelli, Giovanni; Vernelli, Valeria

    2013-07-02

    The aim of this research is to assess the sustainability of a natural fiber, such as hemp (Cannabis sativa), and its use as thermal insulator for building applications. The sustainability of hemp was quantified by life cycle assessment (LCA) and particular attention was given to the amount of CO2eq of the whole process, and the indicator greenhouse gas protocol (GGP) was selected to quantify CO2eq emissions. In this study also CO2 uptake of hemp was considered. Two different allocation procedures (i.e., mass and economic) were adopted. Other indicators, such as Cumulative Energy Demand (CED) and EcoIndicator99 H were calculated. The production of 1 ha yielded 15 ton of hemp, whose global warming potential (GWP100) was equal to about -26.01 ton CO2eq: the amount allocated to the technical fiber (20% of the total amount of hemp biomass) was -5.52 ton CO2eq when mass allocation was used, and -5.54 ton CO2eq when economic allocation was applied. The sustainability for building applications was quantified by considering an insulation panel made by hemp fiber (85%) and polyester fiber (15%) in 1 m(2) of wall having a thermal transmittance (U) equal to 0.2 W/m(2)_K. The environmental performances of the hemp-based panel were compared to those of a rockwool-based one.

  7. Cement blocks with EVA waste for extensive modular green roof: contribution of the components for thermal insulation

    Directory of Open Access Journals (Sweden)

    A. B. DE MELO

    Full Text Available Abstract Green roofs can contribute in many ways to the quality of the environment, being known for reducing the heat transfer to the interior of the buildings. Amongst the available techniques for the execution of this type of covering, the use of light cement blocks which are compatible with the system of extensive modular green roofs is proposed. For the light cement blocks, produced with EVA aggregates (waste from the footwear industry, an additional contribution in the capacity of thermal insulation of the proposed green roof is expected. In the present article, the demonstration of such contribution is intended through measurements carried out in prototypes in hot and humid climates. After characterizing the capacity of thermal insulation of the proposed green roof, with different types of conventional covering as a reference, an additional contribution of the component used in this green roof was identified by making comparisons with measurements collected from another green roof, executed with cement blocks without the presence of the EVA aggregates. In the experiments, external and internal surface temperatures were measured in each of the prototypes' coverings, as well as the air temperatures in the internal and external environments. From the analysis of the data for a typical summer day, it was possible to prove that the proposed green roof presented the lowest temperature ranges, considering the internal air and surface temperatures. The presence of the EVA aggregates in the proposed blocks contributed to the decrease of the internal temperatures.

  8. Preparation and properties of thermal insulation coatings with a sodium stearate-modified shell powder as a filler

    Science.gov (United States)

    Tang, Qiang; Zhang, Ya-mei; Zhang, Pei-gen; Shi, Jin-jie; Tian, Wu-bian; Sun, Zheng-ming

    2017-10-01

    Waste shell stacking with odor and toxicity is a serious hazard to our living environment. To make effective use of the natural resources, the shell powder was applied as a filler of outdoor thermal insulation coatings. Sodium stearate (SS) was used to modify the properties of shell powder to reduce its agglomeration and to increase its compatibility with the emulsion. The oil absorption rate and the spectrum reflectance of the shell powder show that the optimized content of SS as a modifier is 1.5wt%. The total spectrum reflectance of the coating made with the shell powder that is modified at this optimum SS content is 9.33% higher than that without any modification. At the optimum SS content of 1.5wt%, the thermal insulation of the coatings is improved by 1.0°C for the cement mortar board and 1.6°C for the steel plate, respectively. The scouring resistance of the coating with the 1.5wt% SS-modified shell powder is three times that of the coating without modification.

  9. The study of the mobile compressor unit heat losses recovery system waste heat exchanger thermal insulation types influence on the operational efficiency

    Science.gov (United States)

    Yusha, V. L.; Chernov, G. I.; Kalashnikov, A. M.

    2017-08-01

    The paper examines the mobile compressor unit (MCU) heat losses recovery system waste heat exchanger prototype external thermal insulation types influence on the operational efficiency. The study is conducted by means of the numerical method through the modellingof the heat exchange processes carried out in the waste heat exchanger in ANSUS. Thermaflex, mineral wool, penofol, water and air were applied as the heat exchanger external insulation. The study results showed the waste heat exchanger external thermal insulationexistence or absence to have a significant impact on the heat exchanger operational efficiency.

  10. Mechanical Behavior of Syntactic Foams for Deep Sea Thermally Insulated Pipeline

    OpenAIRE

    Choqueuse, Dominique; Davies, Peter; Perreux, Dominique; Sohier, L; Cognard, Jean Yves

    2010-01-01

    Ultra Deep offshore oil exploitation (down to 3000 meters depth) presents new challenges to offshore engineering and operating companies. Flow assurance and particularly the selection of insulation materials to be applied to pipe lines are of primary importance, and are the focus of much industry interest for deepwater applications. Polymeric and composite materials, particularly syntactic foams, are now widely used for this application, so the understanding of their behavior under extreme co...

  11. Thermal mass vs. insulation building envelope design in six climatic regions of South Africa

    CSIR Research Space (South Africa)

    Kumirai, T

    2012-02-01

    Full Text Available and interior spaces, but they are also different with respect to other characteristics. High density materials such as concrete, brick, tiles, earth and water require a significant amount of heat to increase their temperature. They also lose heat slowly... the beneficial effects of insulation are destroyed. Tracer gas tests were used to measure the infiltration rate for a light steel frame (LSF) house which was built on the CSIR building performance laboratory test site. Carbon dioxide was injected...

  12. HiPTI - High Performance Thermal Insulation, Annex 39 to IEA/ECBCS-Implementing Agreement. Vacuum insulation in the building sector. Systems and applications

    Energy Technology Data Exchange (ETDEWEB)

    Binz, A.; Moosmann, A.; Steinke, G.; Schonhardt, U.; Fregnan, F. [Fachhochschule Nordwestschweiz (FHNW), Muttenz (Switzerland); Simmler, H.; Brunner, S.; Ghazi, K.; Bundi, R. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland); Heinemann, U.; Schwab, H. [ZAE Bayern, Wuerzburg (Germany); Cauberg, H.; Tenpierik, M. [Delft University of Technology, Delft (Netherlands); Johannesson, G.; Thorsell, T. [Royal Institute of Technology (KTH), Stockholm (Sweden); Erb, M.; Nussbaumer, B. [Dr. Eicher und Pauli AG, Basel and Bern (Switzerland)

    2005-07-01

    This final report on vacuum insulation panels (VIP) presents and discusses the work done under IEA/Energy Conservation in Buildings and Community Systems (ECBCS) Annex 39, subtask B on the basis of a wide selection of reports from practice. The report shows how the building trade deals with this new material today, the experience gained and the conclusions drawn from this work. As well as presenting recommendations for the practical use of VIP, the report also addresses questions regarding the effective insulation values to be expected with current VIP, whose insulation performance is stated as being a factor of five to eight times better than conventional insulation. The introduction of this novel material in the building trade is discussed. Open questions and risks are examined. The fundamentals of vacuum insulation panels are discussed and the prerequisites, risks and optimal application of these materials in the building trade are examined.

  13. A simultaneous characterization and uncertainty analysis of thermal conductivity and diffusivity of bio-insulate material "Palm date Wood" obtained from a periodic method

    Science.gov (United States)

    Tlijani, M.; Ben Younes, R.; Durastanti, J. F.; Boudenne, A.

    2010-11-01

    A periodic method is used to determine simultaneously both thermal conductivity and diffusivity of various insulate materials at room temperature. The sample is placed between two metallic plates and temperature modulation is applied on the front side of one of the metallic plates. The temperature at the front and rear sides of both plates is measured and the experimental transfer function is calculated. The theoretical thermal heat transfer function is calculated by the quadripole method. Thermal conductivity and diffusivity are simultaneously identified from both real and imaginary parts of the experimental transfer function. The thermophysical parameters of several wood scale samples obtained from palm wood trees and common trees with unknown thermal properties (E) with different thicknesses were studied. The value identified for the thermal conductivity 0.03 Wm-1 K-1 compared with different insulate solid material such as glass, glass-wool and PVC is much better and close to the air conductivity, It allowed us to consider the wood scale extracted from palm wood trees, bio and renewable material as good heat insulator aiming in the future as a use for lightness applications, insulating or as a reinforcement in a given matrix. These potentialities still unknown are stengthened by the enormous quantity of such kind of wood gathered annually from palm trees and considered as wastes.

  14. Ultralow-Threshold and Lightweight Biodegradable Porous PLA/MWCNT with Segregated Conductive Networks for High-Performance Thermal Insulation and Electromagnetic Interference Shielding Applications.

    Science.gov (United States)

    Wang, Guilong; Wang, Long; Mark, Lun Howe; Shaayegan, Vahid; Wang, Guizhen; Li, Huiping; Zhao, Guoqun; Park, Chul B

    2018-01-10

    Lightweight, biodegradable, thermally insulating, and electrically conductive materials play a vital role in achieving the sustainable development of our society. The fabrication of such multifunctional materials is currently very challenging. Here, we report a general, facile, and eco-friendly way for the large-scale fabrication of ultralow-threshold and biodegradable porous polylactic acid (PLA)/multiwalled carbon nanotube (MWCNT) for high-performance thermal insulation and electromagnetic interference (EMI) shielding applications. Thanks to the unique structure of the microporous PLA matrix embedded by conductive 3D MWCNT networks, the lightweight porous PLA/MWCNT with a density of 0.045 g/cm3 possesses a percolation threshold of 0.00094 vol %, which, to our knowledge, is the minimum value reported so far. Furthermore, the material exhibits excellent thermal insulation performance with a thermal conductivity of 27.5 mW·m-1·K-1, which is much lower than the best value of common thermal insulation materials. Moreover, it also shows outstanding EMI shielding performance characterized by its high shielding effectiveness (SE) values and absorption-dominated shielding feature. More importantly, its specific EMI SE is as high as 1010 dB·cm3·g-1, which is superior to those of other shielding materials reported so far. Thus, this novel multifunctional material and its general fabrication methodology provide a promising way to meet the growing demand for high-performance multifunctional materials in sustainable development.

  15. A new method for the determination of thermal properties of the insulation material used in district heating pipes; Ny metod foer att bestaemma fjaerrvaermeroers isoleringsfoermaaga

    Energy Technology Data Exchange (ETDEWEB)

    Adl-Zarrabi, Bijan [SP Swedish National Testing and Research Inst., Boraas (Sweden)

    2005-07-01

    Thermal resistance of district heat pipes declines during its lifetime and this leads to increased thermal losses. To be able to change the insufficient pipes in right time has a large economical impact. The conventional measurement techniques for determinations of thermal properties of insulation of the pipe are abusive and expensive. In the present project the 'Transient Plan Source' TPS-method has been studied as an alternative method. TPS-method can be used in the field and measurements are not time demanding. Thermal conductivity of district heating pipe (polyurethane foam) is measured at 20 deg C and 50 deg C with Transient Plane Source (TPS) method. Three different setups were investigated. In one of the setups the TPS sensor is embedded in the insulation of district heating pipe. Comparison between measured results and the reference value showed that the measured results by TPS method were higher than reference values. It may depend on a number of different parameters, for example TPS method measure bulk properties and the reference value is an apparent value. Relative change of thermal conductivity per Celsius degree of temperature was in the same level as reference value. It is possible to embed the TPS sensor in the insulation of the district heating pipes. The measured relative change of conductivity was in the same range as the reference value. Thus, TPS method can be used for control measurements concerning the insulation properties of district heating pipes in the field and in service.

  16. Description and characterization of systems for external insulation and retrofitting for Denmark with emphasis on the thermal performance

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian; Svendsen, Sv Aa Højgaard

    1998-01-01

    to solve these problems insulation is often part of the retrofitting. As internal insulation has many disadvantages with regards to heat and moisture only systems for external insulation will be mentioned here.As there are several different systems for external insulation, each with different properties...

  17. Multi-scale cellulose based new bio-aerogel composites with thermal super-insulating and tunable mechanical properties.

    Science.gov (United States)

    Seantier, Bastien; Bendahou, Dounia; Bendahou, Abdelkader; Grohens, Yves; Kaddami, Hamid

    2016-03-15

    Bio-composite aerogels based on bleached cellulose fibers (BCF) and cellulose nanoparticles having various morphological and physico-chemical characteristics are prepared by a freeze-drying technique and characterized. The various composite aerogels obtained were compared to a BCF aerogel used as the reference. Severe changes in the material morphology were observed by SEM and AFM due to a variation of the cellulose nanoparticle properties such as the aspect ratio, the crystalline index and the surface charge density. BCF fibers form a 3D network and they are surrounded by the cellulose nanoparticle thin films inducing a significant reduction of the size of the pores in comparison with a neat BCF based aerogel. BET analyses confirm the appearance of a new organization structure with pores of nanometric sizes. As a consequence, a decrease of the thermal conductivities is observed from 28mWm(-1)K(-1) (BCF aerogel) to 23mWm(-1)K(-1) (bio-composite aerogel), which is below the air conductivity (25mWm(-1)K(-1)). This improvement of the insulation properties for composite materials is more pronounced for aerogels based on cellulose nanoparticles having a low crystalline index and high surface charge (NFC-2h). The significant improvement of their insulation properties allows the bio-composite aerogels to enter the super-insulating materials family. The characteristics of cellulose nanoparticles also influence the mechanical properties of the bio-composite aerogels. A significant improvement of the mechanical properties under compression is obtained by self-organization, yielding a multi-scale architecture of the cellulose nanoparticles in the bio-composite aerogels. In this case, the mechanical property is more dependent on the morphology of the composite aerogel rather than the intrinsic characteristics of the cellulose nanoparticles. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Ultra-low thermal conductivities of hot-pressed attapulgite and its potential as thermal insulation material

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuan; Ren, Zhifeng, E-mail: bohr123@163.com, E-mail: zren@uh.edu [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States); Wang, Xiuzhang [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States); Hubei Key Laboratory of Pollutant Analysis and Reuse Technology and School of Physics and Electronic Science, Hubei Normal University, Huangshi, Hubei 435002 (China); Wang, Yumei [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Tang, Zhongjia; Makarenko, Tatyana; Guloy, Arnold [Department of Chemistry, University of Houston, Houston, Texas 77204 (United States); Zhang, Qinyong, E-mail: bohr123@163.com, E-mail: zren@uh.edu [Center for Advanced Materials and Energy, Xihua University, Chengdu, Sichuan 610039 (China)

    2016-03-07

    In the past, there have been very few reports on thermal properties of attapulgite which is a widely used clay mineral. In this work, we report on extremely low thermal conductivities in attapulgite samples synthesized by hot-pressing. Attapulgite powder was hot-pressed at different temperatures into bulk samples, and a systematic study was conducted on the microstructures and thermal properties. Differential scanning calorimetry analysis shows that hot-pressing induces a rapid dehydration of the attapulgite powders. X-ray diffraction data and scanning/transmission electron microscopy reveal that the hot-pressed attapulgite features high porosity and complex microstructures, including an amorphous phase. As a result, the hot-pressed attapulgite exhibits thermal conductivity less than 2.5 W m{sup −1} K{sup −1} up to 600 °C. For one sample with porosity of 45.7%, the thermal conductivity is as low as 0.34 W m{sup −1} K{sup −1} at 50 °C. This suggests the potential of hot-pressed attapulgite as a candidate for thermal barrier materials.

  19. The Measurement of Thermal Diffusivity in Conductor and Insulator by Photodeflection Technique

    Science.gov (United States)

    Achathongsuk, U.; Rittidach, T.; Tipmonta, P.; Kijamnajsuk, P.; Chotikaprakhan, S.

    2017-09-01

    The purpose of this study is to estimate thermal diffusivities of high thermal diffusivity bulk material as well as low thermal diffusivity bulk material by using many types of fluid such as Ethyl alcohol and water. This method is studied by measuring amplitude and phase of photodeflection signal in various frequency modulations. The experimental setup consists of two laser lines: 1) a pump laser beams through a modulator, varied frequency, controlled by lock-in amplifier and focused on sample surface by lens. 2) a probe laser which parallels with the sample surface and is perpendicular to the pump laser beam. The probe laser deflection signal is obtained by a position sensor which controlled by lock-in amplifier. Thermal diffusivity is calculated by measuring the amplitude and phase of the photodeflection signal and compared with the thermal diffusivity of a standard value. The thermal diffusivity of SGG agrees well with the literature but the thermal diffusivity of Cu is less than the literature value by a factor of ten. The experiment requires further improvement to measure the thermal diffusivity of Cu. However, we succeed in using ethyl alcohol as the coupling medium instead of CCl4 which is highly toxic.

  20. Method and apparatus for measuring temperatures in fabrics and flexible thermal insulations

    Science.gov (United States)

    Kourtides, Demetrius A. (Inventor)

    1995-01-01

    A temperature sensor uses a type R thermocouple wire element in a ceramic sheath to sense temperatures up to 3,200 deg F., and is particularly suitable for flexible insulations. The sensor includes a thermocouple wire embedded in a sheath having two sections disposed at right angles to each other. The junction of the thermocouple is located at one end of one of the sections and the lead wires extend from the other section. The section which includes the junction is secured to a flexible surface with ceramic cement.

  1. A lime based mortar for thermal insulation of medieval church vaults

    DEFF Research Database (Denmark)

    Larsen, P.K.; Hansen, Tessa Kvist

    . The lambda-value of the insulation mortar is 0.08 W/m K or twice the lambda-value for mineral wool. The water vapour permeability is equal to a medieval clay brick, and it has three times higher capacity for liquid water absorption. The mortar was applied to the top side of the vaults in a thickness of 10 cm......, despite a water vapour pressure gradient up to 500 Pa between the nave and attic. There was no reduction in energy consumption the first winter, possibly due to the increased heat loss related to the drying of the mortar....

  2. Comparative Investigation on Thermal Insulation of Polyurethane Composites Filled with Silica Aerogel and Hollow Silica Microsphere.

    Science.gov (United States)

    Liu, Chunyuan; Kim, Jin Seuk; Kwon, Younghwan

    2016-02-01

    This paper presents a comparative study on thermal conductivity of PU composites containing open-cell nano-porous silica aerogel and closed-cell hollow silica microsphere, respectively. The thermal conductivity of PU composites is measured at 30 degrees C with transient hot bridge method. The insertion of polymer in pores of silica aerogel creates mixed interfaces, increasing the thermal conductivity of resulting composites. The measured thermal conductivity of PU composites filled with hollow silica microspheres is estimated using theoretical models, and is in good agreement with Felske model. It appears that the thermal conductivity of composites decreases with increasing the volume fraction (phi) when hollow silica microsphere (eta = 0.916) is used.

  3. Concurrent topology optimization for minimization of total mass considering load-carrying capabilities and thermal insulation simultaneously

    Science.gov (United States)

    Long, Kai; Wang, Xuan; Gu, Xianguang

    2017-09-01

    The present work introduces a novel concurrent optimization formulation to meet the requirements of lightweight design and various constraints simultaneously. Nodal displacement of macrostructure and effective thermal conductivity of microstructure are regarded as the constraint functions, which means taking into account both the load-carrying capabilities and the thermal insulation properties. The effective properties of porous material derived from numerical homogenization are used for macrostructural analysis. Meanwhile, displacement vectors of macrostructures from original and adjoint load cases are used for sensitivity analysis of the microstructure. Design variables in the form of reciprocal functions of relative densities are introduced and used for linearization of the constraint function. The objective function of total mass is approximately expressed by the second order Taylor series expansion. Then, the proposed concurrent optimization problem is solved using a sequential quadratic programming algorithm, by splitting into a series of sub-problems in the form of the quadratic program. Finally, several numerical examples are presented to validate the effectiveness of the proposed optimization method. The various effects including initial designs, prescribed limits of nodal displacement, and effective thermal conductivity on optimized designs are also investigated. An amount of optimized macrostructures and their corresponding microstructures are achieved.

  4. Research and Analyses on Unsteady Heat Transfer of Inner Thermal Insulation Wall during Multi-temperature Refrigerated Transportation

    Science.gov (United States)

    Liu, Guanghai; Xie, Ruhe; Sun, Yongcai

    There are lots of differences between multi-temperature refrigerated vehicles and ordinary ones in many aspects such as structure and running circumstances, hence the hugely different heat-transfer characters and response coefficients. This paper researched the unsteady heat transfer process of the multi-temperature refrigerated vehicle by response coefficients method, numerically calculated the unsteady heat transfer of inner thermal insulation materials in the multi-temperature refrigerated vehicle by computers, and studied the influences of different term numbers of equation root, term numbers of response coefficients on load calculation accuracy. It showed that the accuracy requirement could be met when the root of equation was -25 and the term number of response coefficient was 30.

  5. The thermal insulating materials and its coatings for underground piping; Los aislamientos termicos y sus recubrimientos para tuberias subterraneos

    Energy Technology Data Exchange (ETDEWEB)

    Salcido Lopez, Salvador [Aislantes Minerales, S. A. de C. V. Mexico, D. F. (Mexico)

    1994-12-31

    Energy Saving through the adequate selection and application of the thermal insulating materials, as well as its coatings for underground piping conducting fluids, both at high and at low temperature. The benefits are outlined at economical level for the investor as well as at ecological level (of vital importance today) and are observed as practical examples in industrial and commercial processes. [Espanol] Ahorro de energeticos mediante la adecuada seleccion y aplicacion de los aislamientos termicos, asi como de sus recubrimientos para tuberias subterraneas que conducen fluidos tanto en alta como en baja temperatura. Los beneficios son destacados tanto a nivel economico para el inversionista, como a nivel ecologico (de vital importancia en la actualidad), y son observados con ejemplos practicos en procesos industriales y comerciales.

  6. The regulation of sepiolite surface free energy and its impact on the thermal insulation property of coating.

    Science.gov (United States)

    Chen, Cong; Liang, Jinsheng; Wang, Fei; Tang, Qingguo; Chen, Yalei

    2014-05-01

    Surface modification is used to regulate surface free energy of sepiolite with 3-glycidoxypropyltrimethoxysilanes (3-GPTMS), 3-methacryloxypropyltrimethoxysilanes (3-MAPTMS) and 3-mercaptopropyltrimethoxysilane (3-MPTMS). Through characterization by Fourier transform infrared spectroscopy, surface free energy, zeta potential and sedimentation measurements and infrared emissivity, it is found that the surface free energy of 3-MPTMS modified sepiolite decreases to 31.72 mJ/m2 and the percentage of polar component increases to 89.75%, thus leading to that the infrared emissivity of 3-MPTMS modified sepiolite increase to be higher than 0.8 and the dispersion of sepiolite has been improved. The excellent thermal insulation property of coating is prepared with 10% additive amount of 3-MPTMS modified sepiolite and the temperature difference between upper and lower box of modified sepiolite coatings is 10 degrees C which is higher than the untreated sepiolite.

  7. Impact of Thermal Mass Oriented Measures Over CO2 Emissions Of a Thermally Insulated Lowrise Apartment Building in Izmir, Turkey

    Directory of Open Access Journals (Sweden)

    Mümine Gerçek

    2015-02-01

    Full Text Available Climate change has drawn the attention of many researchers and practitioners to focus on the methods to address the challenges in achieving low-carbon buildings and cities and in future developments. Nevertheless, few studies have explored the impacts of thermal mass applications for the lowest carbon emissions of building operational energy consumption. A comparative study of CO2 emissions due to different wall and floor compositions is presented in accordance with their lifespans for a hot-humid climate site. Aim of this study is to examine the relation between the energy oriented operations and carbon emissions of the building. Firstly, an existing low-rise building in İzmir is selected, then modelled in the dynamic simulation model software DesignBuilder v4 by synchronizing drawings with basic operational principles of the program. Furthermore, various influence factors of building envelope thermal characteristics are selected as follows: type, location, thickness and thermal specifications of materials used by keeping thermal conductivity value constant. At the end, the research presents remarkable influence of thermal mass oriented measures on reducing energy demands and carbon footprints.

  8. Ecological Risks in Residential Premises Arising from Thermal Insulation by Pouring

    Science.gov (United States)

    Timofeeva, S. S.; Timofeev, S. S.

    2017-11-01

    The residents of modern megacities are exposed to environmental risks arising both directly in the urban environment and their own dwellings. Modern polymeric building materials are the sources of toxic substances release into the air that have a significant impact on the population health. The objective of the work is the ecological and hygienic study of the air in the apartments of Irkutsk after repair work on the roof and walls insulation using the technology of pouring and calculation of the potential environmental risk for the residents. The object of the research was the indoor air in one of the houses in Irkutsk tested for formaldehyde and other toxic substances. After putting the house into operation, some defects were found - the freezing of the walls of the building attic part. During the repair work, the mansard part of the building was heat-insulated by the pouring method using the composite material “Poroplast CF 02”. High concentrations of formaldehyde and styrene were detected in the apartments exceeding the MPC in 4-8 times. The hazard ratio for inhalation exposure to harmful substances exceeds the safety level by 10 times. Consequently, there is a high probability of obtaining acute and chronic poisoning and developing cancer.

  9. Methodology for characterization of corrosive agents of thermal insulating foams; Desenvolvimento de metodologia para caracterizacao de agentes corrosivos de espumas de isolamento termico

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Flavio V. Vasques de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Fundacao Coordenacao de Projetos, Pesquisas e Estudos Tecnologicos - COPPETEC; Mattos, Oscar R.; Mota, Rafael O. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Metalurgica e de Materiais; Margarit-Mattos, Isabel C.P. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept. de Processos Organicos; Quintela, Joaquim P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Vieira, Magda M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2005-07-01

    Warming up oil and derivatives is a required procedure to make their transportation more efficient due to the increase in fluidity. Therefore, the use of thermally insulated pipeline becomes essential. The commonly practice has been the use of pipelines covered with an optional anticorrosive coating, followed by a polyurethane foam layer, as thermal insulator, and a polyethylene top coating for mechanical protection. During the life time of the pipeline, local ruptures of the polyethylene coating frequently occur, allowing the water permeation throughout the thermal insulator. This water may cause foam leaching that would release corrosive agents on the external wall pipe. The objective of the present work was to investigate the effects of the blowing agents, the addition of flame retardant to the foam as well as operating temperatures on the generation of corrosive solutions on the external wall of thermally insulated pipes. In this sense, polyurethane foams expanded with HCFC-141b, CFC-11 and CO{sub 2}, with and without flame retardant, were evaluated at the temperatures of 80 and 120 deg C. (author)

  10. Coefficient of Thermal Diffusivity of Insulation Brick Developed from Sawdust and Clays

    Directory of Open Access Journals (Sweden)

    E. Bwayo

    2014-01-01

    Full Text Available This paper presents an experimental result on the effect of particle size of a mixture of ball clay, kaolin, and sawdust on thermal diffusivity of ceramic bricks. A mixture of dry powders of ball clay, kaolin of the same particle size, and sawdust of different particle sizes was mixed in different proportions and then compacted to high pressures before being fired to 950°C. The thermal diffusivity was then determined by an indirect method involving measurement of thermal conductivity, density, and specific heat capacity. The study reveals that coefficient of thermal diffusivity increases with decrease in particle size of kaolin and ball clay but decreases with increase in particle size of sawdust.

  11. Thermally driven analog of the Barkhausen effect at the metal-insulator transition in vanadium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Huber-Rodriguez, Benjamin; Ji, Heng; Chen, Chih-Wei [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States); Kwang, Siu Yi [Department of Physics, National University of Singapore, Singapore 117551 (Singapore); Hardy, Will J. [Applied Physics Program, Rice Quantum Institute, Rice University, Houston, Texas 77005 (United States); Morosan, Emilia [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005 (United States); Natelson, Douglas [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005 (United States); Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States)

    2014-09-29

    The physics of the metal-insulator transition (MIT) in vanadium dioxide remains a subject of intense interest. Because of the complicating effects of elastic strain on the phase transition, there is interest in comparatively strain-free means of examining VO{sub 2} material properties. We report contact-free, low-strain studies of the MIT through an inductive bridge approach sensitive to the magnetic response of VO{sub 2} powder. Rather than observing the expected step-like change in susceptibility at the transition, we argue that the measured response is dominated by an analog of the Barkhausen effect, due to the extremely sharp jump in the magnetic response of each grain as a function of time as the material is cycled across the phase boundary. This effect suggests that future measurements could access the dynamics of this and similar phase transitions.

  12. Measurement of Insulation Compaction in the Cryogenic Fuel Tanks at Kennedy Space Center by Fast/Thermal Neutron Techniques

    Science.gov (United States)

    Livingston, R. A.; Schweitzer, J. S.; Parsons, Ann M.; Arens, Ellen E.

    2010-01-01

    The liquid hydrogen and oxygen cryogenic storage tanks at John F. Kennedy Space Center (KSC) use expanded perlite as thermal insulation. Th ere is evidence that some of the perlite has compacted over time, com promising the thermal performance and possibly also structural integr ity of the tanks. Therefore an Non-destructive Testing (NDT) method for measuring the perlite density or void fraction is urgently needed. Methods based on neutrons are good candidates because they can readil y penetrate through the 1.75 cm outer steel shell and through the ent ire 120 cm thickness of the perlite zone. Neutrons interact with the nuclei of materials to produce characteristic gamma rays which are the n detected. The gamma ray signal strength is proportional to the atom ic number density. Consequently, if the perlite is compacted then the count rates in the individual peaks in the gamma ray spectrum will i ncrease. Perlite is a feldspathic volcanic rock made up of the major elements Si, AI, Na, K and 0 along with some water. With commercially available portable neutron generators it is possible to produce simul taneously fluxes of neutrons in two energy ranges: fast (14 MeV) and thermal (25 meV). Fast neutrons produce gamma rays by inelastic scatt ering which is sensitive to Fe and O. Thermal neutrons produce gamma rays by radiative capture in prompt gamma neutron activation (PGNA) and this is sensitive to Si, AI, Na, Kand H. Thus the two energy ranges produce complementary information. The R&D program has three phases: numerical simulations of neutron and gamma ray transport with MCNP s oftware, evaluation of the system in the laboratory on test articles and finally mapping of the perlite density in the cryogenic tanks at KSC. The preliminary MCNP calculations have shown that the fast/therma l neutron NDT method is capable of distinguishing between expanded an d compacted perlite with excellent statistics.

  13. DYNAMICS MODEL OF MOISTURE IN PAPER INSULATION-TRANSFORMER OIL SYSTEM IN NON-STATIONARY THERMAL MODES OF THE POWER TRANSFORMER

    Directory of Open Access Journals (Sweden)

    V.V. Vasilevskij

    2016-06-01

    Full Text Available Introduction. An important problem in power transformers resource prognosis is the formation of moisture dynamics trends of transformer insulation. Purpose. Increasing the accuracy of power transformer insulation resource assessment based on accounting of moisture dynamics in interrelation with temperature dynamics. Working out of moisture dynamics model in paper insulation-transformer oil system in conjunction with thermodynamic model, load model and technical maintenance model. Methodology. The mathematical models used for describe the moisture dynamics are grounded on nonlinear differential equations. Interrelation moisture dynamics model with thermodynamic, load and technical maintenance models described by UML model. For confirming the adequacy of model used computer simulation. Results. We have implemented the model of moisture dynamics in power transformers insulation in interrelation with other models, which describe the state of power transformer in operation. The proposed model allows us to form detailed trends of moisture dynamics in power transformers insulation basing on monitoring data or power transformers operational factors simulation results. We have performed computer simulation of moisture exchange processes and calculation of transformer insulation resource for different moisture trends. Originality. The offered model takes into account moisture dynamics in power transformers insulation under the influence of changes of the power transformers thermal mode and operational factors. Practical value. The offered model can be used in power transformers monitoring systems for automation of resource assessment of oil-immersed power transformers paper insulation at different phase of lifecycle. Model also can be used for assessment of projected economic efficiency of power transformers exploitation in projected operating conditions.

  14. ZrW2O8-doped epoxy as low thermal expansion insulating materials for superconducting feeder system

    Science.gov (United States)

    Chu, Xinxin; Wu, Zhixiong; Huang, Chuanjun; Huang, Rongjin; Zhou, Yuan; Li, Laifeng

    2012-12-01

    Epoxy resin insulating materials used in superconducting feeder system of fusion device are required to be low thermal expansion coefficient (TEC). In this paper, negative thermal expansion (NTE) material ZrW2O8 filled epoxy resins were fabricated. To improve the dispersion of fillers in epoxy matrix, plasma polymerization was performed on the surface of ZrW2O8 powders. Transmission electron microscope (TEM) and surface wettability analysis were performed before and after the surface modification of ZrW2O8 powders. The TEC of ZrW2O8/epoxy composites were measured from 77 K to room temperature. The results show the doping of ZrW2O8 can significantly reduce the TEC of epoxy resins. The sedimentation rate of ZrW2O8 before and after modified in epoxy was compared by density measurement. It can be seen that the ZrW2O8 surface modified by plasma polymerization can enhance its dispersion properties in epoxy matrix.

  15. Light and Strong Hierarchical Porous SiC Foam for Efficient Electromagnetic Interference Shielding and Thermal Insulation at Elevated Temperatures.

    Science.gov (United States)

    Liang, Caiyun; Wang, Zhenfeng; Wu, Lina; Zhang, Xiaochen; Wang, Huan; Wang, Zhijiang

    2017-09-06

    A novel light but strong SiC foam with hierarchical porous architecture was fabricated by using dough as raw material via carbonization followed by carbothermal reduction with silicon source. A significant synergistic effect is achieved by embedding meso- and nanopores in a microsized porous skeleton, which endows the SiC foam with high-performance electromagnetic interference (EMI) shielding, thermal insulation, and mechanical properties. The microsized skeleton withstands high stress. The meso- and nanosized pores enhance multiple reflection of the incident electromagnetic waves and elongate the path of heat transfer. For the hierarchical porous SiC foam with 72.8% porosity, EMI shielding can be higher than 20 dB, and specific EMI effectiveness exceeds 24.8 dB·cm3·g-1 at a frequency of 11 GHz at 25-600 °C, which is 3 times higher than that of dense SiC ceramic. The thermal conductivity reaches as low as 0.02 W·m-1·K-1, which is comparable to that of aerogel. The compressive strength is as high as 9.8 MPa. Given the chemical and high-temperature stability of SiC, the fabricated SiC foam is a promising candidate for modern aircraft and automobile applications.

  16. Analysis of the temperature dependence of the thermal conductivity of insulating single crystal oxides

    Directory of Open Access Journals (Sweden)

    E. Langenberg

    2016-10-01

    Full Text Available The temperature dependence of the thermal conductivity of 27 different single crystal oxides is reported from ≈20 K to 350 K. These crystals have been selected among the most common substrates for growing epitaxial thin-film oxides, spanning over a range of lattice parameters from ≈3.7 Å to ≈12.5 Å. Different contributions to the phonon relaxation time are discussed on the basis of the Debye model. This work provides a database for the selection of appropriate substrates for thin-film growth according to their desired thermal properties, for applications in which heat management is important.

  17. Experimental Study on Thermal Performance of Externally Insulated Walls of Intermittent Air-Conditioned Rooms in Summer in Hot Summer and Cold Winter Region, China

    Directory of Open Access Journals (Sweden)

    Yong Ding

    2014-01-01

    Full Text Available Now requirements for the thermal performance of building walls are based on the assumption that heat flux transfers in one direction through the wall. However, in Hot Summer and Cold Winter Region of China, the direction of heat flow in the wall not only changes with the seasons, but also changes in the same period of using. In this paper, dynamic thermal process of externally insulated walls in different air-conditioner’s running state in summer in Chongqing, China, was tested. The distribution characteristics of the outdoor and indoor air temperature and the surface and inner temperatures of the wall were analyzed and demonstrated. Based on the unsteady-state heat transfer theory, the study calculated and analyzed the distribution characteristics of the direction of the heat flux in the thermal process. Also the characteristics of insulation and heat preservation for walls under different air-conditioner’s running state were analyzed. It is shown that, in any air-conditioner’s running state, the direction of the heat flux through the wall is obviously dynamically changing. There is obvious difference in the thermal performance needs of the wall; that is, it has strong demand for thermal insulation in daytime and strong demand for heat dissipation during night time in summer.

  18. Assessment of Uncertainties for the NIST 1016 mm Guarded-Hot-Plate Apparatus: Extended Analysis for Low-Density Fibrous-Glass Thermal Insulation.

    Science.gov (United States)

    Zarr, Robert R

    2010-01-01

    An assessment of uncertainties for the National Institute of Standards and Technology (NIST) 1016 mm Guarded-Hot-Plate apparatus is presented. The uncertainties are reported in a format consistent with current NIST policy on the expression of measurement uncertainty. The report describes a procedure for determination of component uncertainties for thermal conductivity and thermal resistance for the apparatus under operation in either the double-sided or single-sided mode of operation. An extensive example for computation of uncertainties for the single-sided mode of operation is provided for a low-density fibrous-glass blanket thermal insulation. For this material, the relative expanded uncertainty for thermal resistance increases from 1 % for a thickness of 25.4 mm to 3 % for a thickness of 228.6 mm. Although these uncertainties have been developed for a particular insulation material, the procedure and, to a lesser extent, the results are applicable to other insulation materials measured at a mean temperature close to 297 K (23.9 °C, 75 °F). The analysis identifies dominant components of uncertainty and, thus, potential areas for future improvement in the measurement process. For the NIST 1016 mm Guarded-Hot-Plate apparatus, considerable improvement, especially at higher values of thermal resistance, may be realized by developing better control strategies for guarding that include better measurement techniques for the guard gap thermopile voltage and the temperature sensors.

  19. Thermal conductivity and Kapitza resistance of cyanate ester epoxy mix and tri-functional epoxy electrical insulations at superfluid helium temperature

    CERN Document Server

    Pietrowicz, S; Jones, S; Canfer, S; Baudouy, B

    2012-01-01

    In the framework of the European Union FP7 project EuCARD, two composite insulation systems made of cyanate ester epoxy mix and tri-functional epoxy (TGPAP-DETDA) with S-glass fiber have been thermally tested as possible candidates to be the electrical insulation of 13 T Nb3Sn high field magnets under development for this program. Since it is expected to be operated in pressurized superfluid helium at 1.9 K and 1 atm, the thermal conductivity and the Kapitza resistance are the most important input parameters for the thermal design of this type of magnet and have been determined in this study. For determining these thermal properties, three sheets of each material with different thicknesses varying from 245 μm to 598 μm have been tested in steady-state condition in the temperature range of 1.6 K - 2.0 K. The thermal conductivity for the tri-functional epoxy (TGPAP-DETDA) epoxy resin insulation is found to be k=[(34.2±5.5).T-(16.4±8.2)]×10-3 Wm-1K-1 and for the cyanate ester epoxy k=[(26.8±4.8).T- (9.6±5...

  20. Thermal math model analysis of FRSI test article subjected to cold soak and entry environments. [Flexible Reuseable Surface Insulation in Space Shuttle Orbiter

    Science.gov (United States)

    Gallegos, J. J.

    1978-01-01

    A multi-objective test program was conducted at the NASA/JSC Radiant Heat Test Facility in which an aluminum skin/stringer test panel insulated with FRSI (Flexible Reusable Surface Insulation) was subjected to 24 simulated Space Shuttle Orbiter ascent/entry heating cycles with a cold soak in between in the 10th and 20th cycles. A two-dimensional thermal math model was developed and utilized to predict the thermal performance of the FRSI. Results are presented which indicate that the modeling techniques and property values have been proven adequate in predicting peak structure temperatures and entry thermal responses from both an ambient and cold soak condition of an FRSI covered aluminum structure.

  1. Silanization of boron nitride nanosheets (BNNSs) through microfluidization and their use for producing thermally conductive and electrically insulating polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Seyhan, A.Tuğrul, E-mail: atseyhan@anadolu.edu.tr [Department of Materials Science and Engineering, Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey); Composite Materials Manufacturing Science Laboratory (CMMSL), Research and Application Center of Civil Aviation (RACCA), Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey); Göncü, Yapıncak; Durukan, Oya; Akay, Atakan; Ay, Nuran [Department of Materials Science and Engineering, Anadolu University - AU, Iki Eylul Campus, 26550 Eskisehir (Turkey)

    2017-05-15

    to make it possible to utilize them as promising filler constituent in manufacturing thermally conductive and electrically insulating polymer nanocomposites that could be considered as whole or a part of a heat-releasing device.

  2. Silanization of boron nitride nanosheets (BNNSs) through microfluidization and their use for producing thermally conductive and electrically insulating polymer nanocomposites

    Science.gov (United States)

    Seyhan, A. Tuğrul; Göncü, Yapıncak; Durukan, Oya; Akay, Atakan; Ay, Nuran

    2017-05-01

    to make it possible to utilize them as promising filler constituent in manufacturing thermally conductive and electrically insulating polymer nanocomposites that could be considered as whole or a part of a heat-releasing device.

  3. Anharmonic phonon quasiparticle theory of zero-point and thermal shifts in insulators: Heat capacity, bulk modulus, and thermal expansion

    Science.gov (United States)

    Allen, Philip B.

    2015-08-01

    The quasiharmonic (QH) approximation uses harmonic vibrational frequencies ωQ ,H(V ) computed at volumes V near V0 where the Born-Oppenheimer (BO) energy Eel(V ) is minimum. When this is used in the harmonic free energy, QH approximation gives a good zeroth order theory of thermal expansion and first-order theory of bulk modulus, where nth-order means smaller than the leading term by ɛn, where ɛ =ℏ ωvib/Eel or kBT /Eel , and Eel is an electronic energy scale, typically 2 to 10 eV. Experiment often shows evidence for next-order corrections. When such corrections are needed, anharmonic interactions must be included. The most accessible measure of anharmonicity is the quasiparticle (QP) energy ωQ(V ,T ) seen experimentally by vibrational spectroscopy. However, this cannot just be inserted into the harmonic free energy FH. In this paper, a free energy is found that corrects the double-counting of anharmonic interactions that is made when F is approximated by FH( ωQ(V ,T ) ) . The term "QP thermodynamics" is used for this way of treating anharmonicity. It enables (n +1 ) -order corrections if QH theory is accurate to order n . This procedure is used to give corrections to the specific heat and volume thermal expansion. The QH formulas for isothermal (BT) and adiabatic (BS) bulk moduli are clarified, and the route to higher-order corrections is indicated.

  4. Selecting the Best Thermal Building Insulation Using a Multi-Attribute Decision Model

    Science.gov (United States)

    2008-03-01

    fundamental concepts of heat transfer ; this will include the modes of heat transfer and the concept of the rated thermal conductivity (R-value). The...movement of mass . Conductive heat transfer generally increases as the density of the medium increases. Fourier’s law describes the rate at which a...2007. Incropera , Frank and DeWitt, David. Introduction to Heat Transfer 4th ed. John Wiley and Sons, Inc., 1996. Intergovernmental Panel on

  5. Thermal behavior of underground power transmission lines with SF/sub 6/ insulation

    Energy Technology Data Exchange (ETDEWEB)

    Brueggemann, G.

    1977-12-01

    For the calculation of the stationary load of underground SF/sub 6/ cables, a method is proposed which also takes into account the natural temperature gradient in the thermally not influenced ground as well as the uneven temperature distribution on the outer tube at any given geometric formation. A long-time test confirms the calculations. The transient behavior is described by means of time constants.

  6. Description of the manufacturing challenges in producing the high-temperature reusable surface insulation for the thermal protection system of the Space Shuttle

    Science.gov (United States)

    Forsberg, K.

    1979-01-01

    The paper describes the high-temperature reusable surface insulation for the thermal protection system of the Space Shuttle. This system protects the Space Shuttle Orbiter on reentry and it is an externally attached, rigidized, fibrous silica, machined into 15 x 20 cm tiles. The tiles constitute the High-Temperature Reusable Surface Insulation (HRSI) system, and are used on over 70 percent of the exterior surface where peak temperatures range from 400 to 1260 C. Carbon-carbon leading edges are used in areas where peak temperatures exceed 1650 C, and a Nomex felt flexible insulation system is used in regions below 400 C. Approximately 32,000 tiles are used in the HRSI system, and due to vehicle configuration and aerodynamic requirements no two tiles are alike.

  7. Effects of aging on the structural, mechanical, and thermal properties of the silicone rubber current transformer insulation bushing for a 500 kV substation.

    Science.gov (United States)

    Wang, Zhigao; Zhang, Xinghai; Wang, Fangqiang; Lan, Xinsheng; Zhou, Yiqian

    2016-01-01

    In order to analyze the cracking and aging reason of the silicone rubber current transformer (CT) insulation bushing used for 8 years from a 500 kV alternating current substation, characteristics including Fourier transform infrared (FTIR) spectroscopy, mechanical properties analysis, hardness, and thermo gravimetric analysis have been carried out. The FTIR results indicated that the external surface of the silicone rubber CT insulation bushing suffered from more serious aging than the internal part, fracture of side chain Si-C bond was much more than the backbone. Mechanical properties and thermal stability results illustrated that the main aging reasons were the breakage of side chain Si-C bond and the excessive cross-linking reaction of the backbone. This study can provide valuable basis for evaluating degradation mechanism and aging state of the silicone rubber insulation bushing in electric power field.

  8. High loads and their influence on thermal insulation of insulating materials; Extreme Beanspruchungen und deren Auswirkungen auf die Waermedaemmwirkung von Daemmstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, R.

    2001-12-14

    Changing climatical conditions like strong rain, high temperatures or vibration loads, can reduce sensitively the efficiency of heat insulating materials involving an expensive sanitation. [German] Durch extrem veraenderte klimatische Randbedingungen im Anwendungsfall, wie z.B. Auftreten von Wasser, ueberhoehte Temperatur oder Schwingbeanspruchungen, ist mit einer Verminderung der Waermedaemmwirkung von Daemmstoffprodukten zu rechnen. (orig.)

  9. IMPACT ON THE APPLICATION OF INSULATION IN BUILDINGS TO ACHIEVE THERMAL COMFORT (A CASE STUDY: LAUSER OFFICE BUILDING IN BANDA ACEH

    Directory of Open Access Journals (Sweden)

    Nova Purnama Lisa

    2014-12-01

    Full Text Available From the results of research studies on the impact of the use of insulation in buildings, reducing solar radiation on buildings to improve indoor comfort by applying the Principles of radiation reduction in buildings naturally using insulation application that serves as an insulator against the building materials, use of thermal insulation in particular mounted on the roof of the building and the walls are located on second floor and the third floor Lauser office building, Calculate the cooling load for each room that was on second floor and the third floor based on the geographical location or position of the building, climate data, building material data , and the intensity of the spatial characteristics which include lighting, solar radiation, user activity and electrical appliances being used. The calculation is done with the help of Ecotech v.5, 2011. The location and position on the third floor of a building with a flat roof cast concrete, so that the heat absorbed by the platform, and two times greater than the amount of heat radiation is absorbed by the material in the direction of the light falling the sun is at an angle <30°C. The simulation results on the building with the addition of thermal insulation on all walls and the roof of the inside of the foam material ultrafolmadehid, without changing the model building and similar activities in accordance with the existing condition and the condition of the room using the air conditioner at a temperature of 18-26°C, indicating a decrease in cooling load signifinikan in any space reaches 40% of the total cooling load required on the lauser office building. Comparing the simulation results Ecotech temperature v.5 2011 with field measurements as a validation of the simulation results in order to achieve thermal comfort in buildings and can menggurangi use energy consumption in buildings and can be used as a reference in planning space-based conditioning systems energy efficient.

  10. An employee sews thermal insulation material on the back cover and heat shield of the Huygens probe

    Science.gov (United States)

    1997-01-01

    An employee in the Payload Hazardous Servicing Facility (PHSF) sews thermal insulation material on the back cover and heat shield of the Huygens probe during prelaunch processing, testing and integration in that facility. The Huygens probe and the Cassini orbiter being processed at KSC are the two primary components of the Cassini spacecraft, which will be launched on a Titan IVB/Centaur expendable launch vehicle from Cape Canaveral Air Station. Cassini will explore Saturn, its rings and moons for four years. The Huygens probe, designed and developed for the European Space Agency (ESA), will be deployed from the orbiter to study the clouds, atmosphere and surface of Saturn's largest moon, Titan. The orbiter was designed and assembled at NASA's Jet Propulsion Laboratory in California. Following postflight inspections, integration of the 12 science instruments not already installed on the orbiter will be completed. Then, the parabolic high-gain antenna and the propulsion module will be mated to the orbiter, followed by the Huygens probe, which will complete spacecraft integration. The Cassini mission is targeted for an Oct. 6 launch to begin its 6.7-year journey to the Saturnian system. Arrival at the planet is expected to occur around July 1, 2004.

  11. An employee sews thermal insulation material on the front heat shield of the Huygens probe in the PH

    Science.gov (United States)

    1997-01-01

    An employee in the Payload Hazardous Servicing Facility (PHSF) sews thermal insulation material on the front heat shield of the Huygens probe during prelaunch processing testing and integration in that facility, with the probe's back cover in the background. The Huygens probe and the Cassini orbiter being processed at KSC are the two primary components of the Cassini spacecraft, which will be launched on a Titan IVB/Centaur expendable launch vehicle from Cape Canaveral Air Station. Cassini will explore Saturn, its rings and moons for four years. The Huygens probe, designed and developed for the European Space Agency (ESA), will be deployed from the orbiter to study the clouds, atmosphere and surface of Saturn's largest moon, Titan. The orbiter was designed and assembled at NASA's Jet Propulsion Laboratory in California. Following postflight inspections, integration of the 12 science instruments not already installed on the orbiter will be completed. Then, the parabolic high-gain antenna and the propulsion module will be mated to the orbiter, followed by the Huygens probe, which will complete spacecraft integration. The Cassini mission is targeted for an Oct. 6 launch to begin its 6.7-year journey to the Saturnian system. Arrival at the planet is expected to occur around July 1, 2004.

  12. Chemical vapor deposition and analysis of thermally insulating ZrO{sub 2} layers on injection molds

    Energy Technology Data Exchange (ETDEWEB)

    Atakan, Burak; Khlopyanova, Victoria; Mausberg, Simon; Kandzia, Adrian; Pflitsch, Christian [Thermodynamik (IVG) and Cenide, Universitaet Duisburg-Essen, Lotharstr. 1, 47057 Duisburg (Germany); Mumme, Frank [Kunststoff-Institut Luedenscheid, Karolinenstrasse 8, 58507 Luedenscheid (Germany)

    2015-07-15

    High quality injection molding requires a precise control of cooling rates. Thermal barrier coating (TBC) of zirconia with a thickness of 20-40 μm on polished stainless steel molds could provide the necessary insulating effect. This paper presents results of zirconia deposition on stainless steel substrates using chemical vapor deposition (CVD) aiming to provide the process parameters for the deposition of uniform zirconia films with such a thickness. The deposition was performed with zirconium (IV) acetylacetonate (Zr(C{sub 5}H{sub 7}O{sub 2}){sub 4}) as precursor and synthetic air as co-reactant, which allows deposition at temperatures below 600 C. The experiments were carried out in a hot-wall reactor at pressures between 7.5 mbar and 500 mbar and in a temperature range from 450 C to 600 C. Important growth parameters were characterized and growth rates between 1 and 2.5 μm/h were achieved. Thick and well adhering zirconia layers of 38 μm could be produced on steel within 40 h. The transient heat transfer rate upon contact with a hot surface was also evaluated experimentally with the thickest coatings. These exhibit a good TBC performance. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Unique fur and skin structure in harbour seals (Phoca vitulina)--thermal insulation, drag reduction, or both?

    Science.gov (United States)

    Erdsack, Nicola; Dehnhardt, Guido; Witt, Martin; Wree, Andreas; Siebert, Ursula; Hanke, Wolf

    2015-03-06

    Vertebrate surface structures, including mammalian skin and hair structures, have undergone various modifications during evolution in accordance with functional specializations. Harbour seals rely on their vibrissal system for orientation and foraging. To maintain tactile sensitivity even at low temperatures, the vibrissal follicles are heated up intensely, which could cause severe heat loss to the environment. We analysed skin samples of different body parts of harbour seals, and expected to see higher hair densities at the vibrissal pads as a way to reduce heat loss. In addition to significantly higher hair densities around the vibrissae than on the rest of the body, we show a unique fur structure of hair bundles consisting of broad guard hairs along with hairs of a new type, smaller than guard hairs but broader than underhairs, which we defined as 'intermediate hairs'. This fur composition has not been reported for any mammal so far and may serve for thermal insulation as well as drag reduction. Furthermore, we describe a scale-like skin structure that also presumably plays a role in drag reduction. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  14. Transparent thermal insulation for a fabrication hall of LHB, Salzgitter; Transparent gedaemmte Fertigungshalle bei LHB in Salzgitter

    Energy Technology Data Exchange (ETDEWEB)

    Galetzky, A. [Linke-Hofmann-Busch Waggon - Fahrzeug - Maschinen GmbH, Salzgitter (Germany); Goller, M. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany)

    1997-12-31

    Many industrial workshops in Germany were erected during the 40s and 50s, especially at the beginning of the economic boom. After more than 40 years, these facilities are in need of structural and production-technical modernization. A case in point is the carriage fabrication workshop of the Salzgitter-based company Linke-Hoffmann-Busch. The characteristic features of this type of building are large glazed areas, free uncontrolled ventilation and substantial height. Opportunities for energy-oriented and light-technical modernization are demonstrated at this Salzgitter workshop in exemplary form, the emphasis being on the use of solar energy components and, particularly, transparent thermal insulation. (orig.) [Deutsch] In der Bundesrepublik Deutschland gibt es viele Produktionshallen, die in den vierziger und fuenfziger Jahren, insbesondere zu Beginn des wirtschaftlichen Aufschwungs, errichtet wurden. Diese Hallen sind nach ueber vierzig Jahren sowohl aus baulichen als auch produktionstechnischen Gruenden sanierungsbeduerftig. Die Halle 1, Waggonneubau, der Linke-Hofmann-Busch GmbH in Salzgitter ist ein typischer Vertreter dieser Art von Hallen. Sie zeichnen sich durch grosse Verglasungsflaechen, freie unkontrollierte Lueftung und relativ grosse Bauhoehe aus. Exemplarisch werden an dieser Halle Moeglichkeiten einer energetischen und lichttechnischen Sanierung aufgezeigt, wobei der Einsatz von Solarenergiekomponenten und insbesondere der Transparenten Waermedaemmung besondere Beruecksichtigung erfaehrt. (orig.)

  15. Sensitivity of dual-wall structures under hypervelocity impact to multi-layer thermal insulation thickness and placement

    Science.gov (United States)

    Schonberg, William P.

    1993-01-01

    Results are presented from an experimental study in which Al dual-wall structures were tested, under various high-speed impact conditions, with a view to the effect of multilayer insulation thickness and location on perforation resistance. Attention is given to comparisons of the damage sustained by dual-wall systems with multilayer insulation blankets of various thicknesses and at various locations within the dual-wall system, under comparable impact loading conditions. The placement of the insulation has a significant effect on the ballistic limit of the dual-wall structures considered, while reducing insulation thickness by as much as a third did not.

  16. A facial one-pot route synthesis and characterization of Y-stabilized Sb{sub 2}O{sub 3} solar reflective thermal insulating coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhengjun [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Liu Jie, E-mail: liujie@shnu.edu.cn [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Wang Feijiu [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Yu Xibin, E-mail: xibinyu@shnu.edu.cn [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China)

    2011-10-17

    Highlights: {yields} Sb{sub 2}O{sub 3} nanoparticles were prepared via a facile one-pot ball-milling route. {yields} Sb{sub 2}O{sub 3} based coatings have high solar reflectance properties. {yields} Sb{sub 2}O{sub 3} based coatings have excellent thermal insulation properties. {yields} Sb{sub 2}O{sub 3} based coatings may find applications in the energy saving of constructions. - Abstract: An efficient solar reflective thermal insulating coatings (SRCs) based on Y-stabilized Sb{sub 2}O{sub 3} nanoparticles has been prepared via a facile one-pot ball-milling route. Y-stabilized Sb{sub 2}O{sub 3} have smaller particle size (about 5 nm), disperse more evenly in coating films and exhibit higher solar reflectance compared with pure Sb{sub 2}O{sub 3}. Y-stabilized Sb{sub 2}O{sub 3} SRCs have the reflectance of more than 90% in the region 450-1600 nm and more than 80% in the region 1600-2200 nm and excellent thermal insulating properties. The observed solar reflectance properties of Y-stabilized Sb{sub 2}O{sub 3} SRCs were explained on the basis of the electronic structure of the material and physical parameters such as mean particle size (crystallite size) and refractive index. Due to its high solar reflectance and excellent thermal insulation properties, as-prepared Y-stabilized Sb{sub 2}O{sub 3} SRCs maybe a promising candidate for the energy saving applications in the constructions and industry furnishment.

  17. Thermal conductivity of carbon felts, insulating materials with a high anisotropy; Conductivite thermique des feutres de carbone, isolants a forte anisotropie

    Energy Technology Data Exchange (ETDEWEB)

    Danes, F.E.; Bardon, J.P. [Centre National de la Recherche Scientifique, 44 - Nantes (France). Lab. de Thermocinetique

    1996-12-31

    Because of their high temperature resistance, carbon felts are used as thermal insulating materials for high temperature applications. The aim of this paper is to present a model that allows to calculate the thermal conductivity of felt fibers taking into account their high anisotropy and the contact resistance of fibers generated by the 3-D constriction phenomena which develop in fibers around each contact point. The study is divided in two parts: the first part concerns the bibliographic study of the different anisotropies of fibers and felts, while the second part presents the proposed conductivity model. (J.S.) 12 refs.

  18. Heat and Mass Transfer in a High-Porous Low-Temperature Thermal Insulation in Real Operating Conditions

    Directory of Open Access Journals (Sweden)

    Polovnikov Vyacheslav Yu.

    2015-01-01

    Full Text Available The results of numerical simulation of heat and mass transfer in a high-porous low-temperature insulation in conditions of insulation freezing, a moisture migration to the front of phase transition and a condensation forming on an outer contour of interaction were obtained. Values of heat leakage were established.

  19. An experimental investigation on morphological, mechanical and thermal properties of date palm particles reinforced polyurethane composites as new ecological insulating materials in building

    Directory of Open Access Journals (Sweden)

    A. Oushabi

    2017-12-01

    Full Text Available The rigid polyurethane (PU with apparent density about 40 kg/m3 was prepared using commercial polyols and polyisocyanate. This reference petrochemical formulation was modified with natural and renewable components such as date palm particles (DPP. The goal of this investigation was to reduce the environmental impacts, and reduce the cost of the petroleum based polyurethane (PU by obtaining polyurethane/date palm particles (PU-DPP composites with the heat insulating and mechanical properties similar or better as in the case of the reference material (PU. The composites were prepared with different (DPP loading; 5%, 10%, and 20% (by weight. The results showed that heat insulating and mechanical properties of the (PU-DPP composites were comparable with those from reference petrochemical formulation (PU. On the other hand these mechanical and thermal performances are competitive with those of other insulating material available on the market. Hence the (PU-DPP is a good candidate for development of efficient, low cost, and safe insulating materials.

  20. Efficient copper vapor laser using metal (Cu, Ag) chlorides in thermal insulation and performance with new prism resonator configurations.

    Science.gov (United States)

    Singh, Bijendra

    2012-12-01

    A copper vapor laser based on the use of copper chloride and silver chloride mixture embedded inside the laser head thermal insulation is successfully demonstrated. The use of external HCl generator cell containing zirconium chloride normally used for its kinetically enhanced mode of operation is completely eliminated. With this new configuration laser power of ~70 W was achieved from a wide aperture ~47-50 mm bore discharge tube with input power of ~5 kW and overall high efficiency of ~1.4% without external supply of HCl vapors to the laser head. In a typical operational cycle the laser initially operates as low temperature CuCl laser with startup time of few minutes and output power of ~10 W during low tube temperature range of ~300-500 °C. Thereafter, the laser transforms itself into efficient kinetically enhanced copper vapor laser (CVL) at high temperature range of ~1200-1600 °C with maximum laser output power of ~70 W. This dual mode of operation observed in a single CVL system is unique and has not been reported so far in any high temperature copper vapor laser. New resonator configurations, namely, the prism resonator in stable and unstable form are successfully demonstrated for the first time in a copper vapor laser to achieve low divergence beam with dramatic increase in misalignment tolerance to ~25 mrad, which is an improvement of about ~50 times compared to standard CVLs with conventional spherical or plane-plane resonators. With these new resonator configurations the CVL functions almost as an "alignment free laser" system with significantly reduced beam divergence of ~0.2 mrad and high optical extraction efficiency of ~70%-80%.

  1. Solar wall heating and daylight use with transparent thermal insulation - the solar environmental wall; Solare Wandheizung und Tageslichtnutzung mit Transparenter Waermedaemmung - die Solare Umweltwand

    Energy Technology Data Exchange (ETDEWEB)

    Platzer, W. [Fachverband Transparente Waermedaemmung e.V., Gundelfingen (Germany)

    2005-07-01

    Construction with the sun means to open building walls for the sun. The building is supposed to benefit directly from daylight and solar heat. Special materials were developed for this purpose, which combine solar transmission and light transmission. They enable the transparent thermal insulation of buildings, abbreviated TWD. Their integration into the facade and the roof offer an intelligent and uncomplicated technology for the use of solar energy, the ''solar environmental wall''. TWD-materials can be used as filling material in various building components and they already constitute a weather-resistant wall. They are thermally-insulating structures or materials, which keep out the heat but allow the transmission of solar radiation and light. TWD-materials maintain their excellent insulating properties almost unchanged even in case of very cold outer temperatures or inclined construction in the roof area. In these cases the convection of components that are only filled with air or gas, can lead to considerable decreases of the U-value (according to DIN EN 673 up to 45%). Good TWD-materials are resistant against humidity, which enables to use them in non-hermetic systems, such as e.g. U-profile glas, too. (orig.)

  2. Experimental study on the influence of different thermal insulation materials on the fire dynamics in a reduced-scale enclosure

    DEFF Research Database (Denmark)

    Leisted, Rolff Ripke; Sørensen, Martin X.; Jomaas, Grunde

    2017-01-01

    in the fire behavior, depending on whether the enclosures were constructed of panels filled with SW or PIR insulation material. The mass losses of the insulation materials showed significant contribution from the PIR cores, regardless of fire load and the non-structural damage. The qualitative behavior...... in the full scale tests than in the scaled experiments. Therefore, it can be concluded that when the energy contribution from the core material remained negligible compared to the gas burner, the measured parameters matched quite well. Therefore, if the insulating core material does not dominate the fire...

  3. Moisture Accumulation and Its Impact on the Thermal Performance of Pipe Insulation for Chilled Water Pipes in High Performance Buildings

    OpenAIRE

    Cai, Shanshan; Cremaschi, Lorenzo; Ghajar, Afshin J.

    2012-01-01

    Mechanical pipe insulation systems are commonly applied to cold piping surfaces in most industrial and commercial buildings in order to limit the heat losses and prevent water vapor condensation on the pipe exterior surfaces. Due to the fact that the surface temperature of these pipelines is normally below the ambient dew point temperature, water vapor diffuses inside the pipe insulation systems and often condenses when it reaches the pipe exterior surfaces. The water droplets accumulated in ...

  4. Heat Transfer Measurements through Thermally Enhanced Insulation Schemes for Nb-Ti Superconducting Magnets operating in He-II

    CERN Document Server

    Granieri, P P

    2011-01-01

    Superconducting magnets submitted to large heat loads, as the low-β quadrupoles for the LHC luminosity upgrade, need the development of new concepts of cable electrical insulation featuring a He-II porous wrapping scheme. This paper reports and discusses recent results of dedicated heat transfer measurements performed on different variants of such schemes, with emphasis on the heat transfer enhancements achievable with respect to the state-of-the-art insulation used for the main LHC magnets.

  5. Listed facades of Eisenhuettenstadt improved with regard to its thermal performance. Inside insulation systems and infrared mirrored coatings; Denkmalgeschuetzte Fassaden in Eisenhuettenstadt - waermeschutztechnisch aufgebessert. Innendaemmsysteme und infrarotreflektierende Beschichtungen

    Energy Technology Data Exchange (ETDEWEB)

    Stopp, H. [Fachhochschule Lausitz (Germany). Fachbereich Versorgungstechnik; Strangfeld, P. [Fachhochschule Lausitz (Germany). Fachbereich Bauingenieurwesen; Kramer, M. [Ingenieurbuero Hoch- und Tiefbau e.G., Eisenhuettenstadt (Germany)

    2001-04-01

    The reconstruction of East German and East European towns and villages becomes more and more a burden and a chance for the national economics. Besides the energy saving of worth preserving facades provides social as well as technical considerations and for the management a potential of conflicts. The hygrothermal effectiveness of the inside insulation and the influence of infrared reflecting coats will be demonstrated and discussed by means of the city centre of Eisenhuettenstadt, today protected as monument. Calcium silicate and a highly insulating board of aerated concrete are used as thermal insulation material. In an uninterrupted wall area their usage causes almost no difficulties. In case of deficiencies in thermal protection technical solutions are also possible, whereby the numerical simulation of the transport processes is a useful tool. Moreover, the following explanations deal with the question to what extent outside coatings with a reduced longwave emission influence unfavourable situations of an inside insulation during winter time positively from a hygrothermical point of view. On outside surfaces of building parts with their in most cases capillary active structures, it is a matter of a complex process of the coupled heat and moisture transport, which requires the consideration of all relevant outside climate components. An increase of the temperature at the cold side of the heat insulating layer by infrared reflecting coatings can be proved numerically. The reduction of the thermal transmission during the heating period can reach about 10% in Central Europe in case of vertical areas. Up to now, this is a merely theoretical results because of permanent pollution and temporary moisture film forming. Besides measurements prove, not all on the market available paintings correspond to their promises with regard to energy efficiency. (orig.) [German] Die Sanierung ostdeutscher sowie osteuropaeischer Staedte und Doerfer ist eine Last und Chance von

  6. Large Scale Testing of a Foam/Multilayer Insulation Thermal Control System (TCS) for Cryogenic Upper Stages

    Science.gov (United States)

    Hastings, Leon; Martin, James

    1998-01-01

    The development of high energy cryogenic upper stages is essential for the efficient delivery of large payloads to various destinations envisioned in future programs. A key element in such upper stages is cryogenic fluid management (CFM) advanced development/technology. Due to the cost of and limited opportunities for orbital experiments, ground testing must be employed to the fullest extent possible. Therefore, a system level test bed termed the Multipurpose Hydrogen Test Bed (MHTB), which is representative in size and shape (3 meter diameter by 3 meter long with a volume of 18 cubic meters) of a fully integrated space transportation vehicle liquid hydrogen propellant tank has been established. To date, upper stage studies have often baselined the foam/multilayer insulation (FMLI) combination concept; however, hardware experience with the concept is minimal and was therefore selected for the MHTB. The foam element (isofoam SS-1 171 with an average thickness of 3.5 centimeters) is designed to protect against ground hold/ascent flight environments, and allows for the use of a dry nitrogen purge as opposed to the more complex/heavy helium purge subsystem normally required with MLI in cryogenic applications. The MLI (45 layers of Double Aluminized Mylar with Dacron spacers) provides protection in the vacuum environment of space and is designed for an on-orbit storage period of 45 days. Several unique features were incorporated in the MLI concept and included: variable density MLI (reduces weight and radiation losses by changing the layer density), larger but fewer DAM perforations for venting during ascent to orbit (reduces radiation losses), and roll wrap installation of the MLI with a commercially established process to lower assembly man-hours and reduce seam heat leak. Thermal performance testing of the MHTB TCS was conducted during three test series conducted between September 1995 and May 1996. Results for the ground hold portion of the tests were as expected

  7. The change of electric field and of some other insulating properties during isochronal annealing in thermally poled Ge-doped silica films

    DEFF Research Database (Denmark)

    Liu, Q.M.; Poumellec, B.; Braga, D.

    2005-01-01

    The secondary electron emission contrast between poled and unpoled regions in thermally poled Ge-doped silica films were measured according to different annealing temperatures and electron doses with electron acceleration energy of 5 keV. It is used for measuring the change on annealing of poling...... induced electric field and other insulating properties like electron traps population and conductivity in high field. Concerning the change of the contrast at low dose arising from the poling electric field, we show that this field begins to disappear at around 450 degrees C and is erased completely...

  8. Remote demolition of the thermal insulation and preparative actions for the demounting of the primary shielding; Fernhantierte Demontage der Waermeisolierung und Vorbereitungen zum Ausbau der Primaerabschirmung

    Energy Technology Data Exchange (ETDEWEB)

    Graf, A.; Fleisch, J.; Neff, S. [WAK GmbH, Eggenstein-Leopoldshafen (Germany); Klute, S.; Koselowski, E. [Siempelkamp Nukleartechnik, Heidelberg (Germany)

    2011-07-01

    The compact sodium cooled reactor (KNK) was the prototype of a fast breeder reactor. The reactor was shut down in 1991, the deconstruction was planned and started. The deconstruction and renaturization is performed according to11 separate decommissioning licenses. The first 8 Licenses are completely fulfilled. The authors describe the work to be performed within the 9th license: after the demounting and cutting of the reactor tank the thermal insulation, the primary shielding and the activated part of the biological shield have to be demounted. Appropriate remote handled demounting tools had to be developed, constructed and tested. The first experiences with the tools show that only few optimizations are required.

  9. Characterization of waste of soda-lime glass generated from lapping process to reuse as filler in composite materials as thermal insulation

    Directory of Open Access Journals (Sweden)

    A. C. P. Galvão

    2015-09-01

    Full Text Available AbstractThe beneficiation plate process by soda-lime glass lapping in the glass industry generates, an untapped residue (waste. The waste of this material is sent to landfills, causing impact on the environment. This work aimed to characterize and evaluate the waste of soda-lime glass (GP lapping. After its acquisition, the GP was processed by grinding and sieving and further characterized by the chemical/mineralogical analysis (XRF, EDS and XRD, SEM morphology, particle size by laser diffraction, thermogravimetric analyses (TGA and DSC and thermophysical analyses. It was observed that the GP particles are irregular and micrometric with the predominant presence of Na, Si and Ca elements characteristic of amorphous soda-lime glass. The assessment of the chemical/mineralogical, morphological, thermophysical and thermal gravimetric characteristics of GP suggest its reuse as reinforcing fillers or filler in composite materials to obtain thermal insulation.

  10. Effects of Thermal and Solvent Aging on Breakdown Voltage of TPE, PBT/PET Alloy, and PBT Insulated Low Voltage Electric Wire

    Directory of Open Access Journals (Sweden)

    Eun-Soo Park

    2013-01-01

    Full Text Available Tests were performed to evaluate the effects of thermal and solvent aging on the mechanical and dielectric breakdown properties of four types of polyester resins, namely, the insulation layer of poly(butylene terephthalat (PBT- based thermoplastic elastomer (TPE, TPE1, poly(butylene 2,6-naphthalate-based TPE (TPE2, PBT/poly(ethylene terephthalate alloy (Alloy, and PBT extruded onto a copper conductor of low voltage electric wire. The tensile specimens used in this series were prepared from the same extruded resins. The prepared electric wires and tensile specimens were thermally aged in air and in toluene, xylene, TCB, and NMP. When Alloy and PBT were thermally aged in toluene, xylene and TCB at 120°C for 6 h, the tensile properties were significantly decreased compared to TPE1 and TPE2 at the same condition. The reduction of elongation at break of Alloy was more discernible than that of PBT. This result indicated that Alloy is more affected by thermal and solvent ageing. Among them, TPE2 showed the highest breakdown voltage (BDV, and it has also the highest BDV after thermal and solvent aging.

  11. Aluminized fiberglass insulation conforms to curved surfaces

    Science.gov (United States)

    1966-01-01

    Layers of fiber glass with outer reflective films of vacuum-deposited aluminum or other reflective metal, provide thermal insulation which conforms to curved surfaces. This insulation has good potential for cryogenic systems.

  12. Active perioperative patient warming using a self-warming blanket (BARRIER EasyWarm) is superior to passive thermal insulation: a multinational, multicenter, randomized trial.

    Science.gov (United States)

    Torossian, Alexander; Van Gerven, Elke; Geertsen, Karin; Horn, Bengt; Van de Velde, Marc; Raeder, Johan

    2016-11-01

    Incidence of inadvertent perioperative hypothermia is still high; therefore, present guidelines advocate "prewarming" for its prevention. Prewarming means preoperative patient skin warming, which minimizes redistribution hypothermia caused by induction of anesthesia. In this study, we compared the new self-warming BARRIER EasyWarm blanket with passive thermal insulation regarding mean perioperative patient core body temperature. Multinational, multicenter randomized prospective open-label controlled trial. Surgical ward, operation room, postanesthesia care unit at 4 European hospitals. A total of 246 adult patients, American Society of Anesthesiologists class I to III undergoing elective orthopedic; gynecologic; or ear, nose, and throat surgery scheduled for 30 to 120 minutes under general anesthesia. Patients received warmed hospital cotton blankets (passive thermal insulation, control group) or BARRIER EasyWarm blanket at least 30 minutes before induction of general anesthesia and throughout the perioperative period (intervention group). The primary efficacy outcome was the perioperative mean core body temperature measured by a tympanic infrared thermometer. Secondary outcomes were hypothermia incidence, change in core body temperature, length of stay in postanesthesia care unit, thermal comfort, patient satisfaction, ease of use, and adverse events related to the BARRIER EasyWarm blanket. The BARRIER EasyWarm blanket significantly improved perioperative core body temperature compared with standard hospital blankets (36.5°C, SD 0.4°C, vs 36.3, SD 0.3°C; Pthermal comfort scores, preoperatively and postoperatively. No serious adverse effects were observed in either group. Perioperative use of the new self-warming blanket improves mean perioperative core body temperature, reduces the incidence of inadvertent perioperative hypothermia, and improves patients' thermal comfort during elective adult surgery. Copyright © 2016 The Authors. Published by Elsevier Inc

  13. MCNP Simulations of Measurement of Insulation Compaction in the Cryogenic Rocket Fuel Tanks at Kennedy Space Center by Fast/Thermal Neutron Techniques

    Science.gov (United States)

    Livingston, R. A.; Schweitzer, J. S.; Parsons, A. M.; Arens, E. E.

    2010-01-01

    MCNP simulations have been run to evaluate the feasibility of using a combination of fast and thermal neutrons as a nondestructive method to measure of the compaction of the perlite insulation in the liquid hydrogen and oxygen cryogenic storage tanks at John F. Kennedy Space Center (KSC). Perlite is a feldspathic volcanic rock made up of the major elements Si, AI, Na, K and 0 along with some water. When heated it expands from four to twenty times its original volume which makes it very useful for thermal insulation. The cryogenic tanks at Kennedy Space Center are spherical with outer diameters of 69-70 feet and lined with a layer of expanded perlite with thicknesses on the order of 120 cm. There is evidence that some of the perlite has compacted over time since the tanks were built 1965, affecting the thermal properties and possibly also the structural integrity of the tanks. With commercially available portable neutron generators it is possible to produce simultaneously fluxes of neutrons in two energy ranges: fast (14 Me V) and thermal (25 me V). The two energy ranges produce complementary information. Fast neutrons produce gamma rays by inelastic scattering, which is sensitive to Fe and O. Thermal neutrons produce gamma rays by prompt gamma neutron activation (PGNA) and this is sensitive to Si, Al, Na, K and H. The compaction of the perlite can be measured by the change in gamma ray signal strength which is proportional to the atomic number densities of the constituent elements. The MCNP simulations were made to determine the magnitude of this change. The tank wall was approximated by a I-dimensional slab geometry with an 11/16" outer carbon steel wall, an inner stainless wall and 120 cm thick perlite zone. Runs were made for cases with expanded perlite, compacted perlite or with various void fractions. Runs were also made to simulate the effect of adding a moderator. Tallies were made for decay-time analysis from t=0 to 10 ms; total detected gamma

  14. Thermal engineering research. [Runge-Kutta investigation of gas flow inside multilayer insulation system for rocket booster fuel tanks

    Science.gov (United States)

    Shih, C. C.

    1973-01-01

    A theoretical investigation of gas flow inside a multilayer insulation system has been made for the case of the broadside pumping process. A set of simultaneous first-order differential equations for the temperature and pressure of the gas mixture was obtained by considering the diffusion mechanism of the gas molecules through the perforations on the insulation layers. A modified Runge-Kutta method was used for numerical experiment. The numerical stability problem was investigated. It has been shown that when the relaxation time is small compared with the time period over which the gas properties change appreciably, the set of differential equations can be replaced by a set of algebraic equations for solution. Numerical examples were given, and comparisons with experimental data were made.

  15. Chromium–niobium co-doped vanadium dioxide films: Large temperature coefficient of resistance and practically no thermal hysteresis of the metal–insulator transition

    Directory of Open Access Journals (Sweden)

    Kenichi Miyazaki

    2016-05-01

    Full Text Available We investigated the effects of chromium (Cr and niobium (Nb co-doping on the temperature coefficient of resistance (TCR and the thermal hysteresis of the metal–insulator transition of vanadium dioxide (VO2 films. We determined the TCR and thermal-hysteresis-width diagram of the V1−x−yCrxNbyO2 films by electrical-transport measurements and we found that the doping conditions x ≳ y and x + y ≥ 0.1 are appropriate for simultaneously realizing a large TCR value and an absence of thermal hysteresis in the films. By using these findings, we developed a V0.90Cr0.06Nb0.04O2 film grown on a TiO2-buffered SiO2/Si substrate that showed practically no thermal hysteresis while retaining a large TCR of 11.9%/K. This study has potential applications in the development of VO2-based uncooled bolometers.

  16. Chromium–niobium co-doped vanadium dioxide films: Large temperature coefficient of resistance and practically no thermal hysteresis of the metal–insulator transition

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Kenichi, E-mail: kenichi-miyazaki@denso.co.jp, E-mail: k.shibuya@aist.go.jp [Denso Corporation, Aichi 470-0111 (Japan); University of Tsukuba, Tsukuba 305-8571 (Japan); Shibuya, Keisuke, E-mail: kenichi-miyazaki@denso.co.jp, E-mail: k.shibuya@aist.go.jp; Sawa, Akihito [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565 (Japan); Suzuki, Megumi; Sakai, Kenichi [Denso Corporation, Aichi 470-0111 (Japan); Fujita, Jun-ichi [University of Tsukuba, Tsukuba 305-8571 (Japan)

    2016-05-15

    We investigated the effects of chromium (Cr) and niobium (Nb) co-doping on the temperature coefficient of resistance (TCR) and the thermal hysteresis of the metal–insulator transition of vanadium dioxide (VO{sub 2}) films. We determined the TCR and thermal-hysteresis-width diagram of the V{sub 1−x−y}Cr{sub x}Nb{sub y}O{sub 2} films by electrical-transport measurements and we found that the doping conditions x ≳ y and x + y ≥ 0.1 are appropriate for simultaneously realizing a large TCR value and an absence of thermal hysteresis in the films. By using these findings, we developed a V{sub 0.90}Cr{sub 0.06}Nb{sub 0.04}O{sub 2} film grown on a TiO{sub 2}-buffered SiO{sub 2}/Si substrate that showed practically no thermal hysteresis while retaining a large TCR of 11.9%/K. This study has potential applications in the development of VO{sub 2}-based uncooled bolometers.

  17. Feasibility study for measurement of insulation compaction in the cryogenic rocket fuel storage tanks at Kennedy Space Center by fast/thermal neutron techniques

    Energy Technology Data Exchange (ETDEWEB)

    Livingston, R. A. [Materials Science and Engineering Dept., U. of Maryland, College Park, MD (United States); Schweitzer, J. S. [Physics Dept., U. of Connecticut, Storrs (United States); Parsons, A. M. [Goddard Space Flight Center, Greenbelt (United States); Arens, E. E. [John F. Kennedy Space Center, FL (United States)

    2014-02-18

    The liquid hydrogen and oxygen cryogenic storage tanks at John F. Kennedy Space Center (KSC) use expanded perlite as thermal insulation. Some of the perlite may have compacted over time, compromising the thermal performance and also the structural integrity of the tanks. Neutrons can readily penetrate through the 1.75 cm outer steel shell and through the entire 120 cm thick perlite zone. Neutrons interactions with materials produce characteristic gamma rays which are then detected. In compacted perlite the count rates in the individual peaks in the gamma ray spectrum will increase. Portable neutron generators can produce neutron simultaneous fluxes in two energy ranges: fast (14 MeV) and thermal (25 meV). Fast neutrons produce gamma rays by inelastic scattering which is sensitive to Si, Al, Fe and O. Thermal neutrons produce gamma rays by radiative capture in prompt gamma neutron activation (PGNA), which is sensitive to Si, Al, Na, K and H among others. The results of computer simulations using the software MCNP and measurements on a test article suggest that the most promising approach would be to operate the system in time-of-flight mode by pulsing the neutron generator and observing the subsequent die away curve in the PGNA signal.

  18. Feasibility study for measurement of insulation compaction in the cryogenic rocket fuel storage tanks at Kennedy Space Center by fast/thermal neutron techniques

    Science.gov (United States)

    Livingston, R. A.; Schweitzer, J. S.; Parsons, A. M.; Arens, E. E.

    2014-02-01

    The liquid hydrogen and oxygen cryogenic storage tanks at John F. Kennedy Space Center (KSC) use expanded perlite as thermal insulation. Some of the perlite may have compacted over time, compromising the thermal performance and also the structural integrity of the tanks. Neutrons can readily penetrate through the 1.75 cm outer steel shell and through the entire 120 cm thick perlite zone. Neutrons interactions with materials produce characteristic gamma rays which are then detected. In compacted perlite the count rates in the individual peaks in the gamma ray spectrum will increase. Portable neutron generators can produce neutron simultaneous fluxes in two energy ranges: fast (14 MeV) and thermal (25 meV). Fast neutrons produce gamma rays by inelastic scattering which is sensitive to Si, Al, Fe and O. Thermal neutrons produce gamma rays by radiative capture in prompt gamma neutron activation (PGNA), which is sensitive to Si, Al, Na, K and H among others. The results of computer simulations using the software MCNP and measurements on a test article suggest that the most promising approach would be to operate the system in time-of-flight mode by pulsing the neutron generator and observing the subsequent die away curve in the PGNA signal.

  19. Plastic Materials for Insulating Applications.

    Science.gov (United States)

    Wang, S. F.; Grossman, S. J.

    1987-01-01

    Discusses the production and use of polymer materials as thermal insulators. Lists several materials that provide varying degrees of insulation. Describes the production of polymer foam and focuses on the major applications of polystyrene foam, polyurethane foam, and polyisocyanurate foam. (TW)

  20. Thermal insulation field replacement for operating high temperature oil; Substituicao in situ do revestimento isolante termico de dutos que transportam oleo combustivel aquecido, sem paralisacao operacional

    Energy Technology Data Exchange (ETDEWEB)

    Maniero, Leo [Transpavi-Codrasa S.A., Sao Paulo, SP (Brazil); Oliver, Joao H. de L.; Pinto, Mucio E.A. C. [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The in Situ rehabilitation of the thermal isolated coating of heated pipelines required a technology development for material and equipment innovation, in such way, the coating rehabilitation was conducted keeping the continuous pipeline operation at 85 deg C. The new thermal coating is applied after the following services stages: dig the trench, purge the old thermal insulation, sand blasting of the steel pipe, application of a anticorrosive coating in the metallic substratum for continuous operation at 120 deg C, application of spacers around the steel pipe, fabrication of a polyethylene (PE) casing, cut and opening of the PE casing in its own longitudinal line, setting the PE casing over the spacers, closing of the PE casing by longitudinal thermoplastic welding with the automatic machine, boring a opening in the PE casing sidelong, injection of polyurethane foam inside of the PE casing, tampon the bores by thermoplastic weld, tying-in the PE casing with the next contiguous casing with electro fusion weld. The casing-bends are made from the PE casing cut in angles, like the specific project of each bend, the casing-bends are mounted outer the steel pipeline bends follows the same sequences of stages. (author)