Effect Of Insulation Materials Research Articles

Effect of insulation materials and power on microwave heating characteristics of SiC susceptor under material–specific parametric conditions

High-quality microwave absorber materials play a crucial role in the efficient and uniform processing of variety of materials through microwave hybrid heating. Silicon carbide (SiC) is an excellent microwave absorber at room temperature, which enhances the heating rate of the target materials significantly. In the present study, effects of heat insulation materials and their configurations on microwave heating characteristics of SiC were investigated at different power levels. The responses were assessed in terms of the heating capability (maximum temperature achieved), radiation heat loss, temperature gradient, and heating uniformity under different parametric conditions. A 3D COMSOL Multiphysics simulation model, coupled with microwave heating and heat transfer module, was developed with surface-to-ambient radiation boundary conditions. Electromagnetic and thermal properties of the SiC utilized in the model were selected based on physical properties, such as porosity/density, particle size, and chemical composition of SiC. The model outputs were validated with experimental findings. Results showed that microwave heating characteristics were highly sensitive to the susceptor (SiC) properties, insulation materials and power levels. Insulation materials prevented heat losses significantly; at the same time, different insulation configurations altered the electrical field intensity distribution within the SiC sample, which affected the responses. Microwave power levels also influenced the responses and quantity of insulation required.

Effect of Insulation Materials and Phase Change Materials on Thermal Characteristics in Hollow Clay Bricks

Effect of Insulation Materials and Phase Change Materials on Thermal Characteristics in Hollow Clay Bricks

Effect of insulation material on the firing performance of TaN@(Al/Ni)

In order to improve the ignition ability of reactive film, in this paper, the effects of copper oxide and silicon nitride on the flame height of the TaN@(Al/Ni) energy exchanger were investigated by using a high-speed photographic system. The insulating layer material was applied to the preparation TaN@(Al/Ni) by the MEMS process. The experimental results showed that the flame height of (Al/Ni)–TaN energy exchanger was obviously higher than that of silicon nitride when copper oxide was used as the insulation layer, which indicates that the oxygen-containing insulation layer could increase the flame height of the energy exchanger.

Energy and environmental assessment of the chilean social housing: Effect of insulation materials and climates

The impact of the envelope insulation and location of a Chilean single-family dwelling on the energy and environmental performance remains understudied. To figure this out, this study proposes to develop a life cycle assessment of a social housing with different thermal insulation materials and thicknesses (1–15 cm) in seven cities located in different thermal zones. The impact of the insulation and climate conditions is evaluated through the dwelling heating demand and the environmental impact, which allows determining the overall impact of improving the housing envelope by considering a cradle-to-grave approach. The functional unit considered in this study is 1 m2 of the total dwelling floor area. As expected, the heating demand showed notable differences between cities, being more energy-intensive (134–236 kWh/m2 yr) in cities located in Chile's extreme south, such as Punta Arenas. On the other hand, the major environmental impacts were registered in Puerto Montt (600–850 Pt/m2), although this city does not present a high heating and electrical energy consumption.Regarding the insulation material performance, increasing the wall insulation thickness (1–15 cm) decreased the U-value by 31 and 89%, resulting in an energy saving of 57–60% and reducing the environmental impact by 18 and 29%. These findings suggest that the actual thermal standard could be improved for reducing energy consumption and the environmental impact in the cities located in southern Chile. Moreover, the results demonstrate that the environmental impact depends more on the energy resources used to produce heating, electricity and domestic hot water than on the location of the city. It allows to identify potential opportunities to implement feasible and more sustainable solutions for social housing design considering site-specific conditions.

Economic strategies for low-temperature transportation of asphalt pavement: a comparative analysis of temperature variations

ABSTRACT Highway construction strategies impact the early damage of asphalt pavement and its sustainability. The pavement quality is directly influenced by the temperature segregation of the mixture during transportation, which has rarely been investigated. Low-temperature transportation strategies for highway pavement are proposed by assessing the temperature variations in the mixture through field tests. The extreme condition of winter construction is considered, and the effects of insulation materials are considered in laboratory and field tests. A 3D Multiphysics Coupling Finite Element model is developed in COMSOL to analyse the heat transfer mechanism. The vehicle speed, thermal conductivity and ambient temperatures are considered in this parametric study. The economic efficiency of intelligent transportation is improved by optimising the effective area and the thickness of insulation materials. This study aims to propose economic strategies to avoid the temperature segregation of pavement materials and to explore more environmentally friendly insulation measures for low-temperature highway constructions.

Effects of insulation materials and their location on the fire resistance of LSF walls

Lightweight walls incorporate insulation materials to compensate for their low thermal mass and to improve thermal performance. This helps in increasing the energy performance of the buildings. Since insulation materials are sensible heat storage materials, there is an increment in the room temperature. Phase Change Materials (PCMs) are used in lightweight walls due to their high thermal storage capacity and the resulting enhanced thermal comfort levels. However, the performance of the PCM incorporated building products/insulations in fire has not been investigated yet. This research has investigated the fire resistance of Light gauge steel framed (LSF) walls with PCM incorporated cellulose insulation through small-scale fire tests. It has also investigated the effects of using different insulation materials and their location on the fire resistance of LSF walls. Important results of this research are presented in this paper in the form of time-temperature profiles for cavity and externally insulated LSF wall configurations with and without PCM incorporated cellulose insulation. Findings reveal that externally insulated LSF walls have higher fire resistance levels than cavity insulated LSF walls based on insulation failure criterion. Importantly, adding PCM to cellulose insulation improves the fire resistance of both cavity and externally insulated LSF walls. PCM incorporated cellulose insulation can be used externally in LSF walls to enhance their fire and energy performance. However, the fire behaviour of Vacuum Insulation Panel (VIP) incorporated LSF wall is completely different to other wall systems.

Fire Spread in Insulation Materials in the Ceiling of a Piloti-Type Structure

In piloti-type structures, large-scale fires frequently occur because insulation materials in the ceiling are ignited. However, the spread of fire in these cases is not well known. Therefore, this study conducted small-scale (1.0 m × 1.0 m) tests and real-scale model tests. According to the results, we clarified the fire spread, temperature variation over time, and the effects of insulation materials in fire sites. For the small-scale tests, the internal structure of the ceiling was extruded polystyrene (XPS) + sheet molding compound (SMC), retardant expanded polystyrene (Retardant EPS) + sheet molding compound (SMC), and extruded polystyrene (XPS) + design metal ceiling (DMC). From the small-scale and large-scale tests that simulated a fire in a piloti-type structure, the flow of heat in the interior space and the cause of a large fire were identified. The tests were conducted with EPS+DMC, defined as the best-case scenario, and XPS+SMC, defined as the worst-case scenario during a fire accident. The results from the tests showed that combustion began when the insulation material was exposed to the fire source. Then, molten XPS fell onto the SMC, establishing a new fire source that destroyed the ceiling material, leading to increased combustion due to the inflow of oxygen.

Effect of insulation materials and cavity layout on heat transfer of concrete masonry hollow blocks

The aim of this research was to reduce the demand for air conditioning in buildings by minimizing the heat flow from outdoor environment to the interior of building envelopes (walls and roofs). Hence, a finite element model (FEM) was developed to find out the optimum geometry of cavities and their layout in masonry concrete blocks in order to reduce the thermal flow of heat and the results were compared with that of hollow blocks available in the market in terms of thermal insulation. Results of the simulation were promising and indicated that the new “optimum” designed geometry of hollow blocks was much better than the hollow blocks available in the market. Thereafter, some insulation materials were utilized in the concrete mixtures to produce hollow masonry concrete blocks to reduce the thermal conductivity through wall elements. Experimentally, the results of the new block with optimum geometry without the insulation materials showed improved thermal insulation by as much as 71% compared to other designs of hollow blocks including those available in the market. The thermal resistance of concrete and masonry blocks with the insulation materials (perlite, rubber and polyethylene) was enticing and significant. The newly developed optimum design of masonry concrete block with and without the insulation materials satisfied the ASTM C129 requirements for non-load bearing walls in terms of strength and absorption and was considered as medium weight (without insulation material) and as lightweight (with insulation materials) masonry hollow blocks. Results of this comprehensive investigation also indicated that the thermal conductivity could be reduced by up to 40% compared to that of the conventional blocks available in the market. Therefore, it is recommended that these optimum designed blocks be utilized by the construction industry in order to reduce the amount of energy used for the air conditioning as well as the carbon footprrint.

Effects of insulation materials on mass concrete with pozzolans

A mix incorporates cement(II), fly ash, and slag to design mass concrete. A simplified box is set up to measure Ko. Two blocks are established to evaluate the insulation with thin sides (1/2-in.PE; top: none) and thick sides (1-in.XPS and 1-in.EPS; top: 1-in.XPS) and wrapped with canvas. Results for Ko were 1-in.XPS<1-in.PE<1-in.EPS<1/2-in.PE. The maximum temperature differentials are less than 12°C. The insulation effect of the face was 1/2-in.PE<1-in.EPS<1-in XPS, and the top 1-in.XPS enhanced insulation effectively. The values of R2 for Ko vs. λ, λ vs. R-value, Ko and vs. R-value were 0.995, 0.987, and 0.966 to assess appropriate insulation materials.

Effect of an Insulation Layer to Prevent Water Vapor Condensation along the Inside Surface of a Building Wall Using an Artificial Neural Network

AbstractA theoretical analysis was performed to study the attenuation of a heat wave through two composite walls. Each wall was made of three homogenous layers in addition to an insulation layer, all of which were made of local materials. One way to attenuate this heat wave was to apply insulation inside the wall. In this work, an artificial neural network (ANN) was developed to study the effect of insulation materials on a building wall through a four-layered wall. The layer material type, the layer thickness, and the inside and outside temperature were used in the input layer of the network, whereas the temperature distribution was in the output layer of the network. Data that were obtained from previous experiments were used to train the neural network. It was found that the algorithm used (Levenberg-Marquardt) was very much capable of estimating the temperature distribution within each of the four-layered walls with excellent accuracy.

Effect of Insulation Material in Aging Pacing Leads: Comparison of Impedance and Other Electricals

There has been concern over declining bipolar (BP) impedance (Z) in aging polyurethane (PU) cardiac pacing leads. Subsequently, a prospective study was conducted comparing BP Z, threshold (Th), and R-wave sensing amplitude of 55D PU-insulated (Model 4024, Medtronic, Inc., Minneapolis, MN, USA) and silicone-insulated (Model 5024) leads. This study was initiated by The Iowa Heart Center. Patients with Model 4024 (N = 162) or 5024 (N = 120) pacing leads with at least 6 years implant time were enrolled and followed for an additional 5 years. There was a significant drop in the mean BP Z for the Model 4024 population, between enrollment (6 years) and the final endpoint (11 years), which was in contrast to the Model 5024 which did not see a significant drop in its mean BP Z for this same period. The trend difference seen in the means between the two models was statistically significant (P < 0.0001). In addition, a statistically significant relationship was found between dropping BP Z and rising Th (P < 0.0001). The analysis showed that if BP Z dropped below 200 ohms, the probability of having a >3X increase over baseline, in Th at 2.5 V, increases from approximately 3-7% to as high as 30%. A significant drop in BP Z observed in the PU-insulated Model 4024 lead was not present in the silicone-insulated Model 5024 lead. The statistically significant relationship between dropping BP Z and rising Th helps to understand how to better manage patients with aging leads.

Water flow and heat transport including ice/water phase change in porous media: Numerical simulation and application

Abstract According to the basic law of water flow and heat transfer in porous media under freeze/thaw condition, based on the theories of continuum mechanics, thermodynamics and segregation potential, the governing equations for thermo-hydro (TH) coupling model are established. These equations include not only the effects of thermal conductivity, latent heat of phase change and the seepage velocity on temperature distribution, but also the effects of water flow in porous resulted by Soret effect and segregation potential on seepage velocity and water pressure distribution. Compared with the famous TH coupling laboratory test conducted by Mizoguchi, it was found that the presented TH coupled model predicts the freezing process in porous media well and satisfactorily reflects observed phenomena. Combining this basis and the construction of Galongla tunnel in Tibet of China, the effect of insulation materials is analyzed at first, and then research work is done to study the influence of position, thickness and types of insulation materials on heat preservation effect. The research results indicated that the application of insulation material with 6 cm thickness and 600 m long at the entrance, while 400 m long at the exit of Galongla tunnel can prevent the lining and surrounding rock from freezing–thawing damages effectively.