Insulation Coatings Research Articles

INFLUENCE OF BITUMEN-POLYMER AND ASMOL MASTIC COMPOSITIONS ON QUALITY INDICATORS OF MATERIALS FOR ANTI-CORROSION INSULATION OF OIL AND GAS PIPELINES

Underground pipelines operating experience shows that their operating life and reliability largely depend on effectiveness of metal corrosion protection, both internal and external surfaces. In the latter case, along with electrochemical protection, insulation coatings play an important role. In recent years, there has been a trend to use factory-insulated pipes. Its advantages are obvious: high-quality preparation of pipe surface, strict control over compliance with the technological mode of application. However, in some cases it is impossible to do without field coating: during overhaul, diagnostic works on the linear part and process pipelines of pumping stations. In this case, it is relevant the improvement of insulation materials and field coating technologies.The aim of this work was to study the influence of the component composition of bituminous-polymeric and asmolic mastics on their adhesion to the pipe metal and the operational characteristics of the insulating materials. In doing so, the following tasks were solved:A specially developed gravimetric technique to study the interaction of asmol with the metal surface was used. The cover films formed in this process were studied using an electron microscope at a 1000× magnification.It has been shown that when applying asmol coating, its functional groups enter into chemical interaction with the compounds formed on pipe surface. An indirect confirmation of this is an absolute resistance of the asmol coating to repeated flushing with solvents and water. This peculiarity is not observed in the case of bituminous-polymeric coatings: bituminous-polymeric mastic is completely washed off the surface of steel in a similar treatment.Calculating of the «reduced» cost of 1 km of pipeline re-insulation has revealed a significant advantage of asmol-mastic coating over the bituminous-polymeric one from the economic point of view, since the former not only provides a better adherence to the pipe surface, but also achieves significant savings, since a smaller thickness of the protective coating is required.

Controllable Synthesis of Hollow Silica Nanoparticles Using Layered Double Hydroxide Templates and Application for Thermal Insulation Coating.

The innovative hollow silica nanoparticle (HSN) material possesses substantial potential for application in the insulation field. The size and shell thickness of HSN are crucial factors in determining their inherent properties, which, in turn, impact their applicability. This research presents a facile approach to synthesizing HSN in which sodium silicate (Na2SiO3) was utilized as the silica precursor that can be directly deposited onto layered double hydroxide (LDH) nanoparticles without the utilization of any surfactant. A subsequent acid treatment was used to eliminate the templates, resulting in the formation of an HSN devoid of mesopores in silica shells. By utilizing various sizes of LDH cores, obtainable via coprecipitation followed by hydrothermal treatment, we were capable of successfully synthesizing the hollow particles with adjustable diameters ranging from 50 to 200 nm. In addition, the shell thickness is varied from 6.8 to 22.5 nm by varying the silicate solution concentration. Results demonstrate that prepared HSNs have low thermal conductivity and high reflectance in the UV-vis-NIR range (averaging 82.1%). These findings suggest that HSN can be utilized as an effective inorganic filler in the formulation of reflective and thermally insulating coatings.

Applied Insulating Coatings for Gas Distribution Pipelines in the Republic of Belarus and Their Characteristics

Gas distribution system is a production complex, which is part of the gas supply system and consists of organizational and economically interconnected facilities designed to organize the supply of gas directly to consumers. On the national basis of the gas distribution system is formed by about 67.0 thousand km of external distribution gas pipelines, 28.0 thousand km of which are underground steel pipelines. As potentially hazardous objects, steel underground distribution pipelines are subject to higher requirements for corrosion protection. As a rule, they are provided with complex anticorrosion protection, an obligatory component of which is insulation coatings. Taking into account the above mentioned, the definition of general indicators characterizing condition of insulation, the degree of its wear is an actual task. To solve it, for the first time, we have analyzed an array of long-term statistical data on defects of protective coatings of distribution gas pipelines, detected by instrumental method. The values of specific defect density Dd and damageability Ad have been determined for all types of applied protective coatings. The best values have been found for insulation on the basis of heat-shrinkable tapes. The characteristic damage of the protective coating on the basis of bituminous mastics (microcracks), which can be used as an indicator of aging of this type of insulation, has been determined. It has been shown that defect formation in the insulation coatings of gas pipelines up to the present time is, as a rule, a low-intensive process, which has been confirmed, among other things, for gas pipelines operated for a long time. The obtained results were included into the justification of abolition of the previously used 40-year normative service life of steel gas pipelines in the new edition of the Rules of Technical Safety in the Field of Gas Supply of the Republic of Belarus.

Novel Electrical Insulation Coatings for HTS Cables

To develop epoxy based electrical insulation for HTS power cable and other device applications, the suitability of two cryogenic rated commercial epoxies, (MASTERBOND EP29-LPSP and EP37-3FLFAO) were evaluated. Characterization of their electrical breakdown characteristics, mechanical strength, and the interfacial shear strength of the interface with HTS tapes were conducted at room temperature and 77 K. The epoxy materials are ductile at cryogenic temperatures to support their use as electrical insulation of HTS power devices.

Dual-sized hollow particle incorporated fibroin thermal insulating coatings on catheter for cerebral therapeutic hypothermia

Selective endovascular hypothermia has been used to provide cooling-induced cerebral neuroprotection, but current catheters do not support thermally-insulated transfer of cold infusate, which results in an increased exit temperature, causes hemodilution, and limits its cooling efficiency. Herein, air-sprayed fibroin/silica-based coatings combined with chemical vapor deposited parylene-C capping film was prepared on catheter. This coating features in dual-sized-hollow-microparticle incorporated structures with low thermal conductivity. The infusate exit temperature is tunable by adjusting the coating thickness and infusion rate. No peeling or cracking was observed on the coatings under bending and rotational scenarios in the vascular models. Its efficiency was verified in a swine model, and the outlet temperature of coated catheter (75μm thickness) was 1.8-2.0°C lower than that of the uncoated one. This pioneering work on catheter thermal insulation coatings may facilitate the clinical translation of selective endovascular hypothermia for neuroprotection in patients with acute ischemic stroke.

Methods to reduce heat losses when transporting gas through long branch pipelines

The article considers options to reduce heat losses accompanying the process of pipeline transportation of natural gas through long branch pipelines. Computational modeling of the gas cooling process in an extended off-take gas pipeline connecting the main gas pipeline and the gas distribution station has been performed. It is shown that when the length of the gas branch pipeline is long, especially in conditions of reduced flow, the gas temperature at the inlet of the gas distribution station will correspond to the ground temperature. We have developed and substantiated options to reduce the intensity of gas cooling in the off-take gas pipeline, involving an increase in its depth, the use of thermal insulation coatings, as well as the regulation of pressure at the inlet using special technical means. The calculation justification of the technical solution, which involves regulating the pressure at the inlet to the gas pipeline outlet, is performed. The results can be used by gas transportation companies. The implementation of the developed solutions to reduce heat losses will reduce the consumption of energy used for gas heating at gas distribution stations and reduce emissions of combustion products.

Unveiling the Future of Insulator Coatings: Unmatched Corrosion Resistance and Self-Healing Properties of PFPE Lubricating Oil-Infused Hydrophobized CeO2 Surfaces

Corrosion accounts for 52% of the recorded breakdown of insulators utilized in transmission lines, which may interfere with the reliability of power utilities. The CeO2 conversion coating, CeO2-ethylene propylene diene monomer, EPDM composite coating, and Perfluoropolyether PFPE lubricating oil-infused hydrophobized CeO2 composite surfaces were developed on the insulator surface to address these challenges. The properties of these three kinds of structures are compared based on the persistence of coating over insulators installed in a highly contaminated environment. PFPE lubricating oil-infused hydrophobized CeO2 composite surfaces show excellent performance over other approaches. A lubricating oil-infused hydrophobized CeO2 composite of thickness 35.4 µm exhibits contact angles 60°, 85°, and 160°, and contact angle hysteresis of 12°, 10°, and 4°, respectively, after accelerated thermal aging. The proposed approach presents self-healing and corrosion resistance (corrosion rate 0.3 × 10−3 mm/Y, Icorr 1.2 × 10−7), post-accelerated thermal aging. The research outcome is expected to pave the way for incredibly robust insulator coatings.

A Novel Inorganic Aluminum Phosphate-Based Flame Retardant and Thermal Insulation Coating and Performance Analysis.

Currently, most thin-layer expandable coatings are polymer-based, with very few inorganic expandable coatings. Due to the high environmental friendliness of inorganic coatings, studying new types of inorganic coatings is of great significance. A novel amorphous aluminum phosphate-based flame-retardant coating was prepared by modifying it with nano-silica, hollow silica beads, hollow glass microspheres, and boron carbide. A comprehensive study was conducted on the flame retardancy and thermal insulation performance, composition and structural evolution under flame and physical and chemical properties, and the mechanisms of flame retardancy and thermal insulation were elucidated. Large-plate combustion testing, bonding strength testing, XRD, IR, TG-DSC, and SEM testing were all applied in this work. The synergistic effect of the four fillers was very obvious, and a series of AP22XY (nano-silica/silica beads/hollow glass microspheres/boron carbide = 2:2:0:4, 2:2:1:3, 2:2:2:2, 2:2:3:1, 2:2:4:0) coatings were prepared. The change in the ratio of glass microspheres to boron carbide had a significant impact on the composition and structural evolution of the coating, thus reflecting its effectiveness as a flame retardant and thermal insulation. Although decreasing the ratio would promote the formation of borosilicate glass and Al18B4O33 and improve the thermal stability of coatings, the structure inside of the coating, especially the skeleton, would be dense, which is not conducive to thermal insulation. When the ratio of glass microspheres to boron carbide is 3:1, AP2231 shows the best fire resistance. Under the combustion of butane flame at about 1200-1300 °C, the backside temperature reaches a maximum of 226 °C at 10 min, and then the temperature gradually decreases to 175 °C at 60 min. This excellent performance is mainly attributed to three aspects: (1) the foaming and expandability of coatings when exposed to fire, (2) the multiple endothermic reactions the coating undergoes, and (3) the improvement effect of boron carbide. Additionally, AP2231 shows the best bonding performance with a strength of close to 4.5 MPa after combustion, because of the appropriate content matching between borosilicate glass, Al18B4O33, and hollow glass microspheres. The coating has potential application prospects in the construction and transportation fields, such as the protection of structural steel, fire prevention in subways and tunnels, and the prevention of lithium battery fires.

Future High-Efficiency and Zero-Emission Argon Power Cycle Engines: A Review

Review Future High-Efficiency and Zero-Emission Argon Power Cycle Engines: A Review Chenxu Wang , Shaoye Jin , Jun Deng , Weiqi Ding , Yongjian Tang , and Liguang Li ,* School of Automotive Studies, Tongji University, Shanghai 200092, China * Correspondence: liguang@tongji.edu.cn Received: 27 February 2023 Accepted: 23 May 2023 Published: 13 June 2023 Abstract: This paper reviews the theoretical and experimental researches on Argon Power Cycle (APC) engines. Hydrogen-fueled APC is an innovative power system for a high efficiency and zero emissions, which employs argon rather than nitrogen as a diluent. Due to the large specific heat ratio of argon, the thermodynamic efficiency of APC engines is significantly higher compared to conventional internal combustion engines. However, APC engines face the challenge of knock inhibition, especially when using hydrogen as a fuel. Therefore, this paper summarizes the strategies and technologies to suppress the knock of hydrogen-fueled APC engines, including using alternative fuels with greater anti-knock capacity, lean combustion, and water injection. Furthermore, some guidance opinions are also provided for reference about the development and industrialization of APC engines, such as ultra-lean combustion, which uses pistons with thermal insulation coatings, employing low-friction lubricants, and developing efficient multi-component membrane separation system for argon separation.

Preparation of hollow double-shell SiO2@ATO microspheres and applications in thermal insulation coatings

The hollow double-shell Silicon dioxide/antimony doped tin oxide (SiO2@ATO) spherical microspheres with size of 320 nm were prepared by hydrothermal method using PS spheres as templates. The morphology, crystal structure and microstructure of hollow SiO2@ATO microspheres were characterized by XRD, SEM, EDS and HRTEM. In addition, the composite coatings were prepared by adding different contents of hollow SiO2@ATO to the acrylic matrix, and their optical and thermal insulation properties were studied. The light transmittance of the acrylic matrix coating with 1.5 wt% hollow double-shell SiO2@ATO can reach ∼80%. Moreover, it was found that the hollow double-shell SiO2@ATO/acrylic matrix coating lowered the indoor temperature of a homemade incubator by 9.5 °C. Overall, the prepared hollow SiO2@ATO microspheres show a great potential in the application of energy saving windows.

Ixora coccinea L. - A reliable source of nanocellulose for bio-adsorbent applications

Nanocellulose, a subset of nanomaterials made from cellulose, one of the world's most plentiful natural resources, has the potential to offer environmentally friendly, renewable, and sustainable building blocks with enhanced properties for a variety of applications in the nanotechnology field. This article describes the impact of glutaraldehyde (GA) on glycerol plasticized nanocellulose derived from I. coccinea L. plant root. Using a variety of characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR), X-ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM), AFM, tensile and Brunauer-Emmett-Teller (BET) analysis, the effect of GA on glycerol plasticized nano-cellulose was investigated. The tensile modulus of the GA-crosslinked, 2 % glycerol-plasticized nanocellulose scaffolds is higher (88.82 MPa) than that of the regular nanocellulose scaffolds (78.8 MPa). The scaffold Young's modulus has been increased to 86.3 MPa. The results of the BET study proved that the surface area of the GA crosslinked nano-cellulose scaffold improved to129.703 m2/g. The larger surface area in turn results in a greater number of contact sites between consecutive fibers. This enhances the utility of the scaffold as a bio-adsorbent for waste water treatment. The absorbance of textile black dye and methylene blue dye in sunlight using nanocellulose composites as photocatalyst revealed a significant decrease in dye concentration after each hour, demonstrating the composites' bio-adsorbent property. The non-toxic nature, inertness, increased crystallinity index values, and good mechanical qualities are other characteristics of the GA-treated nanocellulose encourages its uses as product packaging, bioengineering materials, tissue engineering, and insulation coatings.

Thermal comfort and flame retardant performance of novel temperature-control coatings with modified phase change material microcapsules

Organic phase change material (PCM) is considered to be promising for building energy efficiency, as it can be directly incorporated into matrix resin to impart thermal storage capacity after being encapsulated in a shell to form phase change material microcapsule (EPCM). However, existing studies have shown that the encapsulation of organic shell materials negatively affects the inherent thermal storage efficiency of PCM and increases its fire hazard. Towards efficient utilization of the thermal storage efficiency of organic PCM and reduction of its fire hazard when applied to building insulation coatings, we decorated halloysite nanotube (HNT) with P, N component (p-HNT) and embedded it into EPCM (p-h-EPCM), which integrated the high thermal conductivity and flame retardancy of p-HNT and developed a high-performance EPCM for thermal regulation coatings. Specifically, p-h-EPCM possesses exceptional thermal stability and has an enthalpy of 113.21 J/g. After mixing p-h-EPCM into epoxy resin (EP/p-h-EPCM), we further investigated its flame-retardant effect and temperature control performance in practical applications. The cone calorimeter (CCT) showed that EP/p-h-EPCM was 35.7 % lower in the peak of heat release rate (pHRR) and 18.97 % lower in the total heat release (THR) compared to the epoxy resin (EP) that incorporated the same mass of EPCM (EP/EPCM). Moreover, the small room test and thermal imager test results showed that EP/p-h-EPCM had the mildest temperature fluctuations of 8.68 °C and 5.23 °C when heating/cooling, respectively. Considering the favorable flame retardant effect and energy-efficient thermal regulation performance, the obtained p-h-EPCM has a broad prospect in the practical application of building temperature-control coatings.

Superhydrophobic Surface on Insulators by Using Perfluoropolyether-Functionalized Silica Nanostructures for Preventing Stress Corrosion Cracking at the Pin–Cement Junction

Stress corrosion accounts for 52% of the recorded breakdown of insulators utilized in transmission lines which may interfere with the reliability of power utilities. The suggested etching-free treatment is a workable environmentally benign method to prevent stress corrosion, even in old insulators with more excellent surface imperfections or cracks. The resilient slippery coating is developed on an insulator surface to address the challenges by infusing perfluoropolyether, lubricating oil into a porous nano-silica surface. The proposed coating layer, thickness 35.4 μm, exhibits superhydrophobicity with contact angle─160°, contact angle hysteresis─4°, self-healing, corrosion resistance with a corrosion rate of 2 × 10–3 mm/Y, Icorr 2.01 × 10–7 A/cm2, and 98% anti-bacterial adhesion performance against sulfate reducing bacterial stains. The outcome of this research is expected to pave the way for an approach to the future creation of incredibly robust etching-free coatings for insulators.

Examination of commercial ceramic coatings for the electrical insulation of Bi-2212 wire

In the last twenty years, a number of studies have been dedicated to the development of thin ceramic coating for the electrical insulation of Ag-sheathed Bi-2212 wires. Instead of preparing a coating by mixing different compounds in house, this technical note examines if commercial acrylic coatings containing TiO2 particles (white paints) could be used to form TiO2 coating on Ag-sheathed Bi-2212 wires. The compatibility of the acrylic coating with the heat treatment of Ag-sheathed Bi-2212 wire was verified by measuring the effect of coating on the critical current. It was found that the critical current is almost unaffected by the presence of the coating. The acrylic coating characteristics (for example drying time versus temperature and coating thickness at different dip coating speed) were studied and used to prepare a reel-to-reel system for coating long wires.

Continuous vapor processes in newly laid concrete

This article presents the results of experiments on the physical processes that occur during the hardening process of concrete in dry hot-climatic seasons and the reduction of their negative effects - as well as on the physical and mechanical properties. Under the influence of solar radiation and high temperature, the amount of water in the newly laid concrete mixture begins to evaporate rapidly. As a result of intensive evaporation of water in the concrete mixture from the bottom to the top, interconnected pores are formed, as a result of which the concrete has a defective structure, and this situation leads to a decrease in concrete strength. As a result of dehydration of the concrete mixture, the cement hydration process slows down and may even stop. If the hardening of the concrete is not adequately controlled, its strength may be only 50% of the design strength. The duration of keeping newly laid concrete under polymer films is determined by the construction laboratory, taking into account specific climatic conditions. Covering the concrete surface with inventory thermal insulation coatings (ITVP). These covers are made by pulling two-layer polyethylene film on wooden or metal frames. They can also be folded and assembled. The effectiveness of this method is not very high, it is considered a waste product.

ТЕПЛОИЗОЛЯЦИОННЫЕ ПОКРЫТИЯ РАЗЛИЧНОГО НАЗНАЧЕНИЯ

The work discusses the study of the possibility of using thermal insulation coatings based on foam in construction. The relevance of the use of thermal insulation coatings is shown – energy saving, heat and noise protection, fire resistance. Advantages of thermal insulation coatings over existing materials are considered. The developed compositions of two environmentally friendly coatings based on organic-mineral compounds are given. The article describes methods of foam stabilization to extend the service life of thermal insulation coatings. The foam stabilization mechanism is based on sol-gel processes when using SiO2 sol and hydration processes when using cement. Foams obtained by those mechanisms are proposed to be called hardening building foams. The article describes the possibility of imparting different colors to thermal insulation coatings by introducing organic dyes into the foaming composition.

Mathematical Modelling of the Cathodically Polarized Pipeline Electric Field Taking Into Account External and Internal Insulation Coating

Mathematical Modelling of the Cathodically Polarized Pipeline Electric Field Taking Into Account External and Internal Insulation Coating

Electrical Conductivity of Additively Manufactured Copper and Silver for Electrical Winding Applications.

Efficient and power-dense electrical machines are critical in driving the next generation of green energy technologies for many industries including automotive, aerospace and energy. However, one of the primary requirements to enable this is the fabrication of compact custom windings with optimised materials and geometries. Electrical machine windings rely on highly electrically conductive materials, and therefore, the Additive Manufacturing (AM) of custom copper (Cu) and silver (Ag) windings offers opportunities to simultaneously improve efficiency through optimised materials, custom geometries and topology and thermal management through integrated cooling strategies. Laser Powder Bed Fusion (L-PBF) is the most mature AM technology for metals, however, laser processing highly reflective and conductive metals such as Cu and Ag is highly challenging due to insufficient energy absorption. In this regard, this study details the 400 W L-PBF processing of high-purity Cu, Ag and Cu-Ag alloys and the resultant electrical conductivity performance. Six Cu and Ag material variants are investigated in four comparative studies characterising the influence of material composition, powder recoating, laser exposure and electropolishing. The highest density and electrical conductivity achieved was 88% and 73% IACS, respectively. To aid in the application of electrical insulation coatings, electropolishing parameters are established to improve surface roughness. Finally, proof-of-concept electrical machine coils are fabricated, highlighting the potential for 400 W L-PBF processing of Cu and Ag, extending the current state of the art.

Результаты внедрения комплекса мероприятий по обеспечению микроклиматических параметров рудничной атмосферы на объектах НШПП «Яреганефть» ООО «ЛУКОЙЛ-Коми»

The Yarega field is currently the only one in Russia where oil production is carried out by the thermal mining method. The deposit was discovered in 1932, and it is located in the southern part of the Timan-Pechora province, in the Ukhta district of the Komi Republic. The oil of the Yarega field has a high viscosity, and in order to ensure its production, the oil-bearing formation is thermally affected by steam supply through steam-falling (injection) wells into the rock mass. Depending on the development system used, steam injection can be carried out both through surface vertical wells and through underground hollow ascending wells. A combination of these methods is also possible. The heated oil-containing liquid from the producing wells located in the underground mining galleries of the mine is delivered to the surface using the existing collection and transportation system. The uniqueness of the technology of thermal mining production of heavy oil creates additional difficulties in the development of various technical solutions due to the lack of experience in operating such objects in Russia. This oil extraction technology is accompanied by an increase in the temperature and humidity of the mine atmosphere in mine workings, due to the presence of heat sources and areas where steam enters the mine working. Despite the applied technical solutions (increasing ventilation performance, cooling the air by spraying cold water, erecting additional concrete fasteners), there is a possibility of the microclimatic parameters of the air in the mine workings going beyond the established limits. In order to normalize the parameters of the mine atmosphere, a whole complex of technical and organized measures is being implemented, including thermal insulation of heat sources using modern materials. The article discusses various technologies for the use of thermal insulation coatings, analyzes their efficiency and offers solutions for choosing the optimal ways to reduce the temperature and humidity of air in the mine workings.

Modulation of Thermal Insulation and Mechanical Property of Silica Aerogel Thermal Insulation Coatings

In this paper, high-performance silica aerogel (SiO2 aerogel) thermal insulation coatings were obtained and profited from the excellent thermal insulation capability of SiO2 aerogel. The comprehensive properties and thermal insulation mechanism of the coatings were investigated via Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), contact angle, and temperature difference tests. Results showed that there was a contradiction between thermal insulation and mechanical property in this coating after the addition amount and proportion of silica aerogel, hollow glass microsphere, glass fibers, aqueous acrylic emulsion, and dispersing agents were optimized carefully. When the mass ratio of hollow glass to SiO2 aerogel microspheres was 1:1, the overall performance of the coating was the best with thermal conductivity of 0.050 W/(m·K) and adhesive strength of 1024 kPa.