Thermal Insulation Effect Research Articles

Mantle temperature under drifting deformable continents during the supercontinent cycle

AbstractThe thermal heterogeneity of the Earth's mantle under the drifting continents during a supercontinent cycle is a controversial issue in earth science. Here, a series of numerical simulations of mantle convection are performed in 3‐D spherical‐shell geometry, incorporating drifting deformable continents and self‐consistent plate tectonics, to evaluate the subcontinental mantle temperature during a supercontinent cycle. Results show that the laterally averaged temperature anomaly of the subcontinental mantle remains within several tens of degrees (±50°C) throughout the simulation time. Even after the formation of the supercontinent and the development of subcontinental plumes due to the subduction of the oceanic plates, the laterally averaged temperature anomaly of the deep mantle under the continent is within +10°C. This implies that there is no substantial temperature difference between the subcontinental and suboceanic mantles during a supercontinent cycle. The temperature anomaly immediately beneath the supercontinent is generally positive owing to the thermal insulation effect and the active upwelling plumes from the core‐mantle boundary. In the present simulation, the formation of a supercontinent causes the laterally averaged subcontinental temperature to increase by a maximum of 50°C, which would produce sufficient tensional force to break up the supercontinent. The regular periodicity of the supercontinent cycles observed in previous 2‐D and 3‐D simulation models with rigid nondeformable continents and without self‐consistent plate tectonics is not confirmed.

Improved heat insulation system (Mirrorpanel) for construction of wood buildings

Abstract A new thermal insulation system (Mirrorpanel) based on an effective thermal insulation of the air by multiple heat reflection of the radiation heat flux was produced at the Innovation Center of the University of West Hungary. The system was created for wood frame structure buildings where the units of the framework provide the fixing points. In the panels of the new system, there are narrow air fields with high thermal resistance and the lamellae in the field have low surface emission properties, which reflect a considerable part of heat radiation. This system of heat reflection and the narrow air fields was formed with the help of stretched foils. Based on the results of tests gained from the small and medium-sized insulation panels, a life-size test building was constructed, where the performance and conduct of the Mirrorpanel can be continuously studied.

An experimental study on the annual surface temperature characteristics of amorphous silicon BIPV window

In this study, a mock-up facility equipped with both BIPV windows and normal clear windows was installed to carry out the actual measurement of long-term surface temperature characteristics as the preliminary step for analyzing the impact of the surface temperature rise of thin film BIPV modules on the PV performance. The measurement was carried out for clear double windows and BIPV double windows simultaneously for each inclined angle (0°, 30°, and 90°) for one year, and various statistical analyses were carried out for the collected annual surface temperature data to investigate the surface temperature characteristics of BIPV windows. The analysis result shows that the temperature of windows applied on the vertical plane rises significantly during the winter season, and the temperature of windows applied on the horizontal plane and the inclined plane rises significantly during the summer season with high solar altitude. Regarding indoor surface temperature of windows which is closely related with the thermal comfort of indoor occupants, the surface temperature of BIPV windows with low solar heat gain coefficient was 1°C lower than that of normal windows during the day time in summer season and was approximately 2°C higher during the night time in winter season due to the thermal insulation effect.

Optimum insulation thickness of walls for energy-saving in hot regions of India

In India, the energy consumption in the building sector is rapidly increasing due to improvement in living standards. Effective thermal insulation of building walls is one of the most effective energy conservation measures for heating, ventilation, and air conditioning applications in buildings. In this study, the thermoeconomic optimisation of insulation thickness on walls of buildings is analysed based on degree days. Thermoeconomic parameters such as optimum insulation thickness, annual electrical energy consumption, annual energy cost and payback period is determined for three different insulation materials for the cities located in India. Database on insulation materials for five cities of India are provided.

Effect of the Geometric Solution of Cladding on the Quality of the Indoor Microclimate

This paper deals with the comparison of the effect of the contact thermal insulation in the connection of the loggia slab to the stair wall of construction panel system T 06-B produced in Prefa Olomouc. Measurements took place in two panel houses, where parameters of internal and external air were measured. The thermally insulated building is compared with the untreated building. The temperature factor at the internal surface, which eliminates the boundary conditions of the measurement, was used as a comparative element. The measured values were statistically evaluated.

Energy Performances of a Passive Building in Marrakech: Parametric Study

This paper deals with the modeling of a villa type house located in the Marrakech (Morocco) suburb. The house is constituted of two floors and was designed to be energy efficient by integrating some passive techniques: overhangs, an Earth-to-Air Heat Exchanger (EAHX), thermal insulation of the roof and external walls. Most of these systems are unusual in Marrakech buildings; thus the objective of this work is to study their effects on the house cooling and heating loads. The modeling of the house is a multi-zone one and it was carried out during one year. The effects of the passive systems on air temperature in the building, as well as on its cooling/heating load, are analyzed through the modeling of 5 cases. The first case is the real house and the others correspond to the lack of one of the system (i.e. the overhang along the south facade in the second floor, thermal insulation of the roof and thermal insulation of external walls), the fifth case correspond to the lack of all the systems (“standard house”). The results show that some of these systems reduce the maximum temperature, while some others act only on the minimum temperature by increasing it. The first systems reduce the cooling load and are very efficient in summer (this is the case, especially, of the thermal insulation of the roof). The other systems reduce the heating load and have a small effect on the cooling load. It should be mentioned that the heating load of the real house is negligible compared to the cooling one. One of the interesting results is that, corresponding to the effect of thermal insulation of external walls. This insulation has a small beneficial effect on the heating load while it increases the cooling load.

Evisto®, a way to produce ultra-thin gravity die castings

The massive use of air gaps in tooling, per the Evisto® concept, can confine the heat contributed by the cast alloy in a small volume. The resulting high die wall temperatures are turned to account to cast parts having ultra-thin walls, of the order of one millimetre thick. Effective thermal insulation limits thermal exchanges to slow the cooling of a cast alloy. The property that best characterizes this effectiveness is the reciprocal of thermal conductivity, thermal resistance. Air was chosen as the insulating material because of its many advantages: very favourable thermal conductivity, limited application cost, and zero purchase cost. Evisto® , an innovative tooling design, has been used to produce plates 1 mm thick measuring 130 by 200 mm and automobile seat backs 1.2 mm thick measuring 390 by 576 mm. The mechanical properties of the castings so produced complied with standard EN 1706 of May 2010 for aluminium alloy castings. A patent application was filed for the Evisto® concept in August 2010.

Glass-Oxide Nanocomposites as Effective Thermal Insulation Materials

ABSTRACTWith extremely disordered atomic structures, a glass possesses a thermal conductivity k that approaches the theoretical minimum of its composition, known as the Einstein’s limit.1 Depending on the material composition and the extent of disorder, the thermal conductivity of some glasses can be down to 0.1-0.3 W/m∙K at room temperature,2,3 representing some of the lowest k values among existing solids. Such a low k can be further reduced by the interfacial phonon scattering within a nanocomposite that can be used for thermal insulation applications. In this work, nanocomposites hot pressed from the mixture of glass nanopowder (GeSe4 or Ge20Te70Se10) and commercial SiO2 nanoparticles, or pure glass nanopowder, are investigated for the potential k reduction. It is found that adding SiO2 nanoparticles will instead increase k if the measured k values for usually porous nanocomposites are converted into those for the corresponding solid (kSolid) with Eucken’s formula. In contrast, pure glass nano-samples always show kSolid data significantly reduced from that for the starting glass. For a pure GeSe4 nano-sample, kSolid would beat the Einstein’s limit for its composition.

Asynchronous responses of East Asian and Indian summer monsoons to mountain uplift shown by regional climate modelling experiments

It has been demonstrated in climate models that both the Indian and East Asian summer monsoons (ISM and EASM) are strengthened by the uplift of the entire Asian orography or Tibetan Plateau (TP) (i.e. bulk mountain uplift). Such an effect is widely perceived as the major mechanism contributing to the evolution of Asian summer monsoons in the Neogene. However, geological evidence suggests more diachronous growth of the Asian orography (i.e. regional mountain uplift) than bulk mountain uplift. This demands a re-evaluation of the relation between mountain uplift and the Asian monsoon in the geological periods. In this study, sensitivity experiments considering the diachronous growth of different parts of the Asian orography are performed using the regional climate model COSMO-CLM to investigate their effects on the Asian summer monsoons. The results show that, different from the bulk mountain uplift, the regional mountain uplift can lead to an asynchronous development of the ISM and EASM. While the ISM is primarily intensified by the thermal insulation (mechanical blocking) effect of the southern TP (Zagros Mountains), the EASM is mainly enhanced by the surface sensible heating of the central, northern and eastern TP. Such elevated surface heating can induce a low-level cyclonic anomaly around the TP that reduces the ISM by suppressing the lower tropospheric monsoon vorticity, but promotes the EASM by strengthening the warm advection from the south of the TP that sustains the monsoon convection. Our findings provide new insights to the evolution of the Asian summer monsoons and their interaction with the tectonic changes in the Neogene.

A New Type Thermal Insulation Fireproofing Wallboard

Exterior thermal insulation technology has many advantages such as light weight, good thermal insulation effect, and so on. So it is widely used in energy-saving building and existing building energy-saving renovation project all over the word. This article describes material selection, product performance and process characteristics of a new type composite phenolic wallboard which has double functions of thermal insulation and fireproofing.

Vacuum Insulation Panels - An Assessment of the Impact of Accelerated Ageing on Service Life

Vacuum insulation panels (VIP) are the most effective thermal insulation and are primarily used where not much space is available and extremely high thermal insulation properties are required. Panels are already widely used for industry (insulation of the front doors and side walls of refrigerators and freezers for domestic appliances), for logistic purposes (transport containers, storage tanks, campers, refrigeration and other vehicles), for the insulation of laboratory and professional devices and insulation of various construction elements, such as elements for doors, furniture. Since the entry of atmospheric air gases into VIP panels represents the most harmful influence on their excellent thermal insulation property, our research was focused on analysis of accelerated ageing and determination of service life caused by this influence. The primary objective of the research was to define the theoretical base supporting measurements of accelerated testing and the connection between ageing and the service life of VIP panels. Arrhenius law of accelerated testing was used as a theoretical support to experimental testing of VIP panels at high temperatures and different exposure times. These results are useful in order to control quality, resistance to ageing and determining the life expectancy of VIP panel products, the characteristics of which can be determined in a significantly shorter time during accelerated testing than during real service life conditions. The accelerated ageing laboratory test measurements and simulation analysis confirm that VIP panels are a durable and high quality product.

Thermal-insulating effect in a quantum harmonic chain with alternating masses

We present an analytical study of the heat conduction in a quantum harmonic chain of oscillators with alternate particle masses. We find that a thermal-insulating effect already observed in some classical models consisting of chains with alternate masses also holds in the quantum version of the one-dimensional harmonic model with thermal reservoirs at the boundaries. Namely, we show that if the heat conduction is to be avoided, then alternating small and large masses in a wire is more effective than having all of the masses equally large. The presence of a similar effect in different models indicates that the phenomenon may be rather general, with possible applications in the heat-flow control.

발열장치를 이용한 기능성 스마트 파운데이션의 구성 시안

This research was intended to design an experimental girdle with thermal insulation function for adult women in their 20s. The design of the experimental girdle was based on the pattern of commercially available girdle. The final pattern of the experimental girdle was established according to the drawing equations determined based on the result of appearance evaluation. The equations were (waist circumference<TEX>${\times}0.88$</TEX>)/2 for waist circumference, (hip circumference<TEX>${\times}0.77$</TEX>)/2 for hip circumference, and (thigh circumference<TEX>${\times}0.85$</TEX>) for thigh circumference. In order to develop a heating device, the most effective fabric heater was adopted based on the experiments about the number of caron fibers, heater size and attachment site. Three heaters-one with a size of <TEX>$14.5{\times}9.5$</TEX> cm, and the other two with the size of <TEX>$8.0{\times}15.0$</TEX> cm-were attached to the areas corresponding to the lower abdomen and the hip, 5 cm below the waist. A heater was developed by connecting these heaters to a controller, 2 batteries (7.4 V 2000 mAh lithium polymer batteries) and a switch (for mode conversion between high/medium/low temperatures). The heater was integrated into the inside of the girdle, so that attachment and detachment were possible without the change of appearance. The tentative configuration plan was proposed for the development of a functional smart girdle with an excellent thermal insulation effect.

Analysis of the building energy balance to investigate the effect of thermal insulation in summer conditions

This article presents the results of a research aimed at obtaining detailed knowledge on the thermal characteristics of the building for the summer performance, particularly focusing on thermal insulation level. A new methodology for the analysis of the parameters having the most effect on space cooling energy performance of a building is presented.The proposed methodology involves analysing the different contributions to the internal air convective heat balance and their interrelations with different boundary conditions. It is applied, by means of a multi-step dynamic numerical simulation, to a parametric analysis of two case studies, a residential and an office building. The contribution of the energy transmission through the building envelope to the building energy performance for cooling is compared with the contribution of the energy not transmitted through the envelope. The influence of the single parameters related to the envelope, and in particular the effect of the thermal insulation level, are investigated through the application of a sensitivity analysis.The methodology could be used in different applications: in the energy design of new buildings or in an energy audit of existing buildings, because of its potentiality to identify critical situations and to quantify the effects of improving solutions.

Preparation and Properties of Rigid Polyurethane Foams Reinforced by Sepiolite Minerals Nanofibers

Rigid polyurethane foams were prepared using sepiolite nanofibers as main functional fillers. The effect of sepiolite nanofibers on the properties of polyurethane foams was studied systematically. Through characterization by scanning electron microscope, X-ray diffraction and property test, it was found that the thermal insulation effect can be maintained, and the mechanical properties can be improved due to the good interfacial bond between sepiolite nanofibers and rigid polyurethane foams.

Insulation and Fireproof Performance of Several New Materials for Exterior Wall

Exterior insulation is currently promoting a building energy-saving insulation technology. Compared with internal insulation, it is a reasonable technique and has its obvious advantages. However, in the insulation material, thermal insulation effect is better, fireproof performance is often worse. Through analyzing several external wall insulation materials’ insulation and fireproof performance, the article recommends a kind of external wall thermal insulation material with good insulation and fireproof performance, to meet the construction needs.

Fired clay masonry units production incorporating two-phase olive mill waste (alperujo)

This work deals with the use of alperujo, the main residue from the two-phase olive oil extraction process, as a raw material in fired clay masonry units production. Different amounts (3, 6 and 12wt%) of clay were substituted by alperujo, and the properties of the resulting ceramic units were compared to those of conventional products. Results show that a number of advantages can be obtained. At 12wt% alperujo addition, masonry units present lower density (1710kgm−3 compared to 1850kgm−3 reference value) and higher thermal insulation effectiveness (18% reduction in the bulk of fired clay thermal conductivity). With respect to mechanical properties, the fired bending strength attained of approximately 14Nmm−2 is sufficiently high for this type of unit. In addition, the heating value obtained from the organic content of the added alperujo can cause a decrease in the heating requirements in the firing process.

Thermal shock behavior of 8YSZ and double-ceramic-layer La2Zr2O7/8YSZ thermal barrier coatings fabricated by atmospheric plasma spraying

The single-ceramic-layer (SCL) 8YSZ (conventional and nanostructured 8YSZ) and double-ceramic-layer (DCL) La2Zr2O7 (LZ)/8YSZ thermal barrier coatings (TBCs) were fabricated by plasma spraying on nickel-based superalloy substrates with NiCrAlY as the bond coat. The thermal shock behavior of the three as-sprayed TBCs at 1000°C and 1200°C was investigated. The results indicate that the thermal cycling lifetime of LZ/8YSZ TBCs is longer than that of SCL 8YSZ TBCs due to the fact that the DCL LZ/8YSZ TBCs further enhance the thermal insulation effect, improve the sintering resistance ability and relieve the thermal mismatch between the ceramic layer and the metallic layer at high temperature. The nanostructured 8YSZ has higher thermal shock resistance ability than that of the conventional 8YSZ TBC which is attributed to the lower tensile stress in plane and higher fracture toughness of the nanostructured 8YSZ layer. The pre-existed cracks in the surface propagate toward the interface vertically under the thermal activation. The nucleation and growth of the horizontal crack along the interface eventually lead to the failure of the coating. The crack propagation modes have been established, and the failure patterns of the three as-sprayed coatings during thermal shock have been discussed in detail.

An experimental research of thermal insulation and storage effect of turf roofs in winter

An experimental research of thermal insulation and storage effect of turf roofs in winter

Study on New Thermal Insulation Construction of Thermal Recovery Boiler

This paper analyzed existing problems of thermal insulation construction of thermal recovery boiler, and studied and designed a new thermal insulation construction of thermal recovery boiler. We carried out thermal insulation transformation for transition section of boiler, and tested the thermal insulation effect of it. According to the test data, we obtain thermal conductivity of thermal insulation construction of transition section of boiler with and without transformation. Contrast analysis shows that thermal insulation effect of new thermal insulation construction of thermal recovery boiler using fibre spray technology is better than common thermal insulation construction.It can be applied widely.