Insulation Construction Research Articles

Использование инфракрасного излучения при упрочнении изоляционных конструкций электрооборудования тягового подвижного состава

Использование инфракрасного излучения при упрочнении изоляционных конструкций электрооборудования тягового подвижного состава

Second-order topological phases protected by chiral symmetry

We study second-order topological insulators and semimetals characterized by chiral symmetry. We investigate topological phase transitions of a model for construction of the two-dimensional second-order topological insulators protected only by chiral symmetry. By the theory of the phase transitions, we propose a second-order topological semimetal and insulators with flat hinge bands in chiral-symmetric three-dimensional systems. The three-dimensional second-order topological phases can be obtained from the stacked two-dimensional second-order topological insulators with chiral symmetry. Moreover, we show that broken chiral symmetry in the three-dimensional second-order topological phase allows a second-order topological insulator with chiral hinge states. We also demonstrate the second-order topological phases by using a lattice model.

Coupled-wire construction of static and Floquet second-order topological insulators

Second-order topological insulators (SOTI) exhibit protected gapless boundary states at their hinges or corners. In this paper, we propose a generic means to construct SOTIs in static and Floquet systems by coupling one-dimensional topological insulator wires along a second dimension through dimerized hopping amplitudes. The Hamiltonian of such SOTIs admits a Kronecker sum structure, making it possible for obtaining its features by analyzing two constituent one-dimensional lattice Hamiltonians defined separately in two orthogonal dimensions. The resulting topological corner states do not rely on any delicate spatial symmetries, but are solely protected by the chiral symmetry of the system. We further utilize our idea to construct Floquet SOTIs, whose number of topological corner states is arbitrarily tunable via changing the hopping amplitudes of the system. Finally, we propose to detect the topological invariants of static and Floquet SOTIs constructed following our approach in experiments by measuring the mean chiral displacements of wavepackets.

Construction of ultraviolet protection, thermal insulation, superhydrophobic and aromatic textile with Al-doped ZnO–embedded lemon microcapsule coatings

Multifunctional textiles combining ultraviolet protection, thermal insulation and superhydrophobic and aromatic performance were successfully prepared using an aluminum-doped zinc oxide (AZO)-embedded lemon microcapsule and SiO2 dual-layer coating. AZO-loaded lemon microcapsules with average diameter of 1.5 µm were obtained via interfacial polymerization. Results showed that the high concentration of the AZO-embedded lemon microcapsule contributed to enhancing the waterproof property, aromatic performance, and visible and near-infrared light transmittance. The lemon content was up to 2.789 mg/g (weight of essence:weight of fabric). The water contact angle was high at 153.35°, exhibiting an outstanding superhydrophobic performance. The light transmittance decreased as the amount of AZO-embedded lemon microcapsule increased. The ultraviolet protection factor value reached 88.78 when the dosage of the AZO-embedded lemon microcapsule was 6%. Given the above research results, the cotton fabric coated with the AZO-embedded lemon microcapsule and SiO2 dual-layer composite coating would have potential applications in the water/oil purification field and functional protective fabrics.

Calculation of cost-optimal combination of building materials and technical systems for nZEB single-family house using global cost calculation method

As a rule, during the design stage of a single-family house, only initial costs are taken into account and optimised. Long-term financial calculations are usually not even made. At the same time, total costs to design, build and operate the building show a real difference in expenses while living in this house. In the case of nearly zero energy buildings (nZEBs), this global cost approach becomes especially useful because of the strict requirements of heating and primary energy, as well as the compulsory use of renewable energy sources, requiring more detailed and comprehensive calculations of a cost-optimal set of solutions. In this study, a nZEB single-family house is analysed in detail using a comparative global cost calculation methodology. Different insulation materials and construction types, as well as two types of windows and various heating systems, are combined to obtain the same calculated annual energy consumption. The economic calculations of each combination are carried out for the calculation period of 30 years, taking into account expected energy price increase, discount rate, etc. These calculations show the cost-optimal variants, allowing the prediction of a more advantageous selection of materials and system use in a nZEB in terms of the real operation costs.

Thermal insulation composite with the use of mining waste

The authors offer the use of environmentally friendly waste of mining plants located in the Arkhangelsk region as a binder to create a thermal insulation construction composite based on basalt fibers. This waste is the saponite-containing material (SCM) recovered from recycle water suspension produced during the enrichment of kimberlite ores from the diamond deposit named after M V Lomonosov (Arkhangelsk region). The SCM has binding properties and they depend on its dimensional characteristics and reach optimum values at an average particle size within 1-2 µm. The test samples of composites obtained at 105 0C with the SCM content varying in the range from 7.5% to 25% and the test samples of composites obtained as a result of thermal modification at up to 1200 0C with the SCM content varying in the range from 15 to 25%, were made under laboratory conditions. The raw mix for thermal insulation composite production contained the SCM as a binder with an average particle size of 1-2 µm, and basalt fibers with an average diameter of 3-6 µm as fibrous filler. Thermal modification of samples was carried out at a temperature up to 1200 0C according to the temperature-time mode used in expanded clay production. As a result of tests, it was found that the composite thermal insulation capacity decreases and compressive strength increases with an increase in the SCM content. Additionally it was noted that thermal modification of thermal insulation composites considerably increases their compressive strength without any impact on the heat transfer coefficient. Thus, it is possible to obtain materials with the specified performance such as the heat transfer coefficient and compressive strength by regulating a percentage ratio of components of the thermal insulation composite based on basalt fibers – the saponite-containing material. Additionally, thermal modification of the studied composite makes it possible to increase considerably compressive strength without changing its heat transfer coefficient. The obtained thermal insulation construction composite is environmentally safe and can withstand high temperatures without breakdown. The SCM will promote the effective solution of environmental problems associated with the development of the diamond deposit named after M V Lomonosov.

Application of High Strength Sound Insulation Decorative Board in Soundproof Wall of Hotel Rooms—A Case Study of Guangzhou Kempinski Garden Hotel

The article based on acoustic insulation performance test of high strength sound insulation decorative board, the design, construction technology and operation key points of the room partition wall are discussed. Examples show that application of high strength sound insulation decorative board in sound insulation is feasible and good, this material could be used for a reference for similar sound insulation construction

Heat Loads Due To Small Penetrations In Multilayer Insulation Blankets

The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to ease the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fourier’s Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at ∼76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

Theoretical construction of weak topological crystalline insulators

Inspired by the discovery of topological crystalline insulators (TCIs) in three-dimensional materials such as Pb[Formula: see text]Sn[Formula: see text]Se(Te), the classification of topological insulators has been extended to other discrete symmetry classes such as crystal point group symmetries. In this paper, we construct and study a simple model of weak TCIs, which will serve as a more viable project in the experimental probe for such new type of topological phases.

Study on Cold Insulation Construction Technology of LNG Low Temperature Storage Tank Wall

The cold insulation construction of LNG low-temperature storage tank is the key process of construction of tank shell and the cold insulation construction of tank wall is both the key point and the difficult point of cold insulation construction. The cold insulation layer of tank wall has characteristics of complicated structure design, frequent overhead operation and high-standard installation, strictly abiding by stipulated procedure. Technique requirements during construction and solution to problems of safety and high efficiency during the entire process of construction and control of construction quality are important guarantees of carrying out cold insulation construction of LNG low-temperature storage tank wall smoothly. This paper cites simulation of cold insulation of LNG low-temperature storage tank wall as example and describes detail contents of structural characteristics of cold insulation layer of tank wall, construction procedures and construction methods.

Thermal study of calcium silicate material synthesized with solid wastes

This work focuses on the thermal characterization of a calcium silicate-based material synthesized with different solid wastes (chamotte and marble) for use as thermal insulation material. Thermal and structural changes occurring during heating were accompanied by differential thermal analysis, thermogravimetric analysis, dilatometric analysis, open photoacoustic cell technique, X-ray diffraction (XRD), and scanning electron microscopy. An endothermic event at 823.2 °C was interpreted as decomposition of carbonates. An exothermic event around 900 °C is associated with the crystallization of calcium silicate phases mainly wollastonite. The themophysical properties of the calcium silicate-based material (thermal diffusivity, thermal conductivity, specific thermal capacity, and thermal effusivity) are influenced by the synthesis temperature. The thermal analysis results agree well with the XRD. The calcium silicate pieces presented low thermal conductivity values (0.227−0.376 W m−1 K−1). These results suggest that the calcium silicate-based materials produced essentially with chamotte and marble wastes has high potential to be used as thermal insulation construction material.

The optimal decision of insulation in cladding structures for energy efficient buildings

Execution of thermal insulation for enclosing structures of residential properties is a sophisticated part of the thermal protection. The choice of insulation materials for external walls is one of the main ways to increase the performance of heat insulation. This article contains thermo-technical calculations of two enclosing structures due to conditions of Saint-Petersburg. According to the results, the thickness of the insulating layer and a total wall thickness of the exterior walls composed of concrete, insulation and sand-cement rendering are smaller than the same characteristics of wall construction of hollow tile, insulation and sand-cement rendering.

3万立LNG储罐整体温度场及热应力分析

采用CATIA软件建立LNG储罐二维、三维实体模型，在HYPERMESH软件里划分六面体网格，导入ANSYS软件计算分析3万立LNG储罐整体温度场及热应力分布。根据计算结果文件，总结3万立LNG储罐温度及热应力分布规律，提出LNG储罐保冷施工的关键控制点，加强对LNG储罐保冷施工质量的管理，提升了LNG施工水平。 CATIA software is used to build two-dimensional and three-dimensional model of LNG storage tank. Hexahedral meshes are generated in HYPERMESH software and ANSYS software is imported to analyze overall temperature field and thermal stress distribution of 30,000 m3 LNG storage tank. According to analysis result file, the distribution regularities of temperature and thermal stress of 30,000 m3 LNG storage tank are concluded; key control points of cold insulation construction of LNG storage tank are highlighted; management of quality of cold insulation construction of LNG storage tank is tightened up and LNG construction level is upgraded.

Coalescing Fiedler and core vertices

The nullity of a graph G is the multiplicity of zero as an eigenvalue in the spectrum of its adjacency matrix. From the interlacing theorem, derived from Cauchy’s inequalities for matrices, a vertex of a graph can be a core vertex if, on deleting the vertex, the nullity decreases, or a Fiedler vertex, otherwise. We adopt a graph theoretical approach to determine conditions required for the identification of a pair of prescribed types of root vertices of two graphs to form a cut-vertex of unique type in the coalescence. Moreover, the nullity of subgraphs obtained by perturbations of the coalescence G is determined relative to the nullity of G. This has direct applications in spectral graph theory as well as in the construction of certain ipso-connected nano-molecular insulators.

Choice and optimization of ratio of components to develop fast-mounted thermostable heat-insulating constructions

Fast-mounted heat-insulating constructions based on foamed synthetic rubbers, polyethylene, and polyurethane are characterized by a thermostability up to 150°C and emit toxic substances when burnt. However, there is a need for heat insulation of surfaces with higher coolant temperatures, such as pipelines, equipment of nuclear and thermal power plants, and heating systems with remote heat sources. One of the most promising types of heat insulation materials for creation of fast-mounted heat insulation constructions is the syntactic foams or thin-film multilayer heat-insulating coatings (TFMHIC), which are created using hollow microspheres and various types of binders. The formation of TFMHIC on the heat-insulating surface is carried out mostly by means of spraying methods that have well proven themselves at coating on flat and cylindrical surfaces of large area, but they turned out ineffective for cylindrical surfaces with a diameter of 300 mm and less, since they are characterized by a large degree of carryover of composite material. This article analyzed the binders and microspheres promising to create the fast-mounted heat-insulating constructions based on TFMHIC with high thermostability. Based on the analysis, a conclusion is drawn that organicsilicon binding and glass microspheres are promising for use in the heat-insulating constructions with thermostability up to 300°C. The results of experimental research are given that point to the possibility of predicting the optimal composition of heat-insulating material characterized by a high degree of filling with microspheres with maintaining the mechanical strength, by means of performing the analysis of rheological characteristics of nonpolymerized liquid compositions of heat-insulation material. The index of tensile strength in bending was the criterion for evaluating the mechanical strength of heat-insulating material. The critical volume concentrations of filling the heat-insulating material with glass microspheres, whose excess leads to a reduction in its strength characteristics, are determined.

LNG低温储罐罐壁保冷施工技术研究

LNG低温储罐的保冷施工是罐体施工的关键工序，而罐壁的保冷施工既是保冷施工的重点也是施工难点。罐壁保冷层具有结构设计复杂、高空作业多、安装标准高的特点，在施工中要严格遵循规定的程序和技术要求，而施工全程的安全高效、施工的质量控制等问题的解决是LNG低温储罐罐壁保冷工作顺利实施的重要保证。文章以模拟LNG低温储罐罐壁空间进行保冷施工为例，对罐壁保冷层的结构特点、施工顺序、施工方法等内容进行详细叙述。 The cold insulation construction of LNG low-temperature storage tank is the key process of construction of tank shell and the cold insulation construction of tank wall is both key point and difficult point of cold insulation construction. The cold insulation layer of tank wall is with characteristics of complicated structure design, frequent overhead operation and high-standard installation, strictly abiding by stipulated procedure and technique requirements during construction. And solution to problems of safety and high efficiency during whole process of construction and control of construction quality is important guarantee of carrying out cold insulation construction of LNG low-temperature storage tank wall smoothly. This paper cites simulation of cold insulation of LNG low-temperature storage tank wall as example and describes detail contents of structure characteristics of cold insulation layer of tank wall, construction procedure and construction methods.

LNG低温管道保冷结构分析及保冷施工技术

针对LNG管道保冷结构不合理，保冷效果差，冷损失量高、施工复杂难度大、安装时间长等难点，研究LNG管道保冷材料种类和性能特点，采用有限元法分析保冷结构和厚度的温度场分布规律，验证保冷结构的合理性，依照文中保冷施工工艺要求进行施工，为LNG管道保冷施工提供参考依据。 Aiming at unreasonable cold insulation structure of LNG pipe, bad effect of cold insulation, high cold loss, complicated and difficult construction and long-time installation etc. difficulties, this paper studies types and performance characteristics of cold insulation material of LNG pipe. In the paper, finite-element method is used to analyze cold insulation structure and distribution regularities of temperature field of thickness and rationality of cold insulation structure is verified. Carrying out construction according to requirements for cold insulation construction technology in the paper will provide reference for cold insulation construction of LNG pipe.

Environmental assessment of façade-building systems and thermal insulation materials for different climatic conditions

In the European Union, the building sector accounts for more than 40% of the total energy consumption and environmental impacts, representing the area with the greatest potential for intervention. In addition to the existing policies that promote energy efficiency in buildings, the embodied energy and the environmental impacts contained in the building materials should be considered. In the case of the construction of insulation façade systems, the environmental implications are different depending on the type of façade system, the insulation materials used and the location of the building. This article aims to provide all of this information for Spain, including not only the production of the components of the façade system but also the installation phase and the transport to the building site. The results show that the most impactful alternative is the ventilated façade combined with the most impactful insulation materials of stone wool and expanded polystyrene. Meanwhile, the most advisable façade in all of the climate zones is the external thermal insulation system combined with any type of insulation. The environmental impacts of insulation materials are very different. Moreover, it is recommended that further studies complete these results with the economic and social implications of the use and maintenance phases for robust decision-making.

Some Methods of Protection of Concrete and Reinforcment of Reinforced-Concrete Foundations exposed to Environmental Impacts

Concrete and reinforcement used for making of reinforced concrete foundations, can be exposed to different aggressive impacts of the environment. As a consequence, reinforced concrete material deteriorates in time. There is a number of methods, i.e. ways to prevent the damage of reinforced concrete foundations. In the paper are mentioned some of the methods such as: proper selection of foundation depth, construction of the gravel layer below the foundations, construction of the proper drainage and construction of adequate moist and water insulation, proper placing and curing of concrete. In additions, during design of concrete mixes, one must take into consideration the degree of exposure of concrete to the external impacts. In the design of the concrete mix, various admixtures are used, providing appropriate water-tightness of concrete and frost resistance. Also various coating chemical can be used as the additional protection of the concrete surface, such as: hydrophobic silicon impregnation chemical, epoxy resins, bitumen sealing strips or self-adhesive strips, bitumen emulsions, synthetic foils (membranes), hydro-insulation cement masses, bentonite barriers, studded foils (membranes) HDPE, bathtub –like structures... A special attention must be paid to the thickness of the protective layer of the concrete, as well as (when needed) to the choice of reinforcement resistant to corrosion.

Energy Saving Measures and Strengthening Thermal Insulation Construction Technology in Residential Building Design

The study was majorly focused on energy-saving measures and strengthening thermal insulation construction technology in residential building design. Through the comprehensively detailed analysis on the energy-consumption issue of residential buildings, the researcher has realized the necessity of energy saving and thermal insulation, which also initiated the reflection and the further-launched discussion on energy-saving measures and thermal insulation construction technology. In the study, the researcher explored and analyzed mainly on several aspects, the factors to consider in energy saving and thermal insulation, the specific energy-saving measures and strengthening thermal insulation construction, and gave many energy-saving measures and thermal insulation constructions that have good application prospect and practical value. Meanwhile, the researcher also simply researched on the preoccupations of these technologies, key design ideas, technical key points and technology implementation standard, as well as briefly introduced them. This study possesses a certain guiding significance for the energy-saving measures of implementation and thermal insulation construction technology selection in the residential building design. By reference to the study, it is possible to make energy-saving measures and thermal insulation construction technology choices in residential building design more extensive and practical, which has significant meaning for building energy consumption reduction.