Разработка системы охлаждения судовых малоразмерных дизелей, работающих при различных температурах забортной воды в условиях лаборатории

In the introduction of the work history was given, the importance of the application of thermal insulation and sound insulating materials in construction, the transfer of heat and sound, and the mechanisms of thermal and sound insulation. The reasons for the use of thermal and sound insulation and the consequences of insufficient heat and sound insulation are given. Heat and sound transfer and three modes of heat transfer and sound transmission in open and indoor spaces are described. In the continuation of the work, the division of thermal insulation materials was given based on formation: natural thermal insulation materials; synthetic thermal insulation materials; products of mineral origin; thermal insulation concretes and mortars and polyurethanes, and what they are made of, thereby distinguishing them and where they are used. The next chapter is the type of sound insulation material, where the characteristics, advantages, and disadvantages of the most common sound insulators are listed. The accent of the work is given to development trends and the most important modern materials for thermal insulation and sound insulation. Development trends state how thermal insulation materials are developed, according to what and what they are trying to improve. The most important modern materials for thermal insulation are singled out: aerogel, foam glass, Rockpanel plates, aerogel university of Singapore (NUS), and Bronya thermal insulation coatings with all their pros and cons. Similarly, innovative sound insulation products are listed below: sound insulation “Shumanet”; silka calcium silicate blocks; Green Glue sound insulation, and eco wool insulation. At the end of the paper, a conclusion was made as a reflection on the entire work.KeywordsHeat conductivityHeraclite platesExpanded polystyrene (EPS)Extruded polystyrene (XPS)Glass woolStone woolThermal insulation concretesThermal insulation mortarsPolyurethanesAerogelFoam glassRockpanel plates

Summary Cellulose nanomaterial (CNM)-based foams and aerogels with thermal conductivities substantially below the value for air attract significant interest as super-insulating materials in energy-efficient green buildings. However, the moisture dependence of the thermal conductivity of hygroscopic CNM-based materials is poorly understood, and the importance of phonon scattering in nanofibrillar foams remains unexplored. Here, we show that the thermal conductivity perpendicular to the aligned nanofibrils in super-insulating ice-templated nanocellulose foams is lower for thinner fibrils and depends strongly on relative humidity (RH), with the lowest thermal conductivity (14 mW m−1 K−1) attained at 35% RH. Molecular simulations show that the thermal boundary conductance is reduced by the moisture-uptake-controlled increase of the fibril-fibril separation distance and increased by the replacement of air with water in the foam walls. Controlling the heat transport of hygroscopic super-insulating nanofibrillar foams by moisture uptake and release is of potential interest in packaging and building applications.

In today’s society there is an increased focus on various energy aspects. Buildings constitute a large part of the total energy consumption in the world. In this respect it is important to have the optimum heat balance in buildings. That is, in a cold climate one wants to have as well thermally insulated building envelopes as possible. However, even in cold climates there might often be relatively long periods of overheating in the buildings, for example, due to solar heat gains and excessive heat loads from miscellaneous indoor activities. In warm climates overheating is most often the case, for example, in office work spaces with large window glass facades and extensive use of electrical equipment. Insulation retrofit is among the most cost-effective measures, even more cost-effective than, for example, solar photovoltaics. The traditional thermal insulation materials of today have typically thermal conductivities between 33 and 40 mW/(mK). State-of-the-art thermal insulation includes vacuum insulation panels (VIPs) with conductivities between 3 and 4 mW/(mK) in fresh condition to typically 8 mW/(mK) after 25 years aging due to water vapor and air diffusion into the VIP core material, which has an open pore structure. Puncturing the VIP envelope causes an increase in the thermal conductivity to about 20 mW/(mK). The main emphasis of this work centers around the possibilities of inventing and developing innovative and robust highly thermal insulating materials. That is, within this work the objective is to go beyond VIPs and other current state-of-the-art technologies. New concepts are introduced, that is, advanced insulation materials (AIMs) as vacuum insulation materials (VIMs), gas insulation materials (GIMs), nano insulation materials (NIMs), and dynamic insulation materials (DIMs). These materials may have closed pore structures (VIMs and GIMs) or either open or closed pore structures (NIMs). The DIMs aim at controlling the material insulation properties, that is, solid state thermal conductivity, emissivity, and pore gas content. Fundamental theoretical studies aimed at developing an understanding of the basics of thermal conductance in solid state matter at an elementary and atomic level have been addressed. The ultimate goal of these studies is to develop tailor-made novel high performance thermal insulation materials and dynamic insulation materials, the latter one enabling to control and regulate the thermal conductivity in the materials themselves, that is from highly insulating to highly conducting. Furthermore, requirements of the future high performance thermal insulation materials and solutions have been proposed. At the moment, the NIM solution seems to represent the best high performance low conductivity thermal solution for the foreseeable future. If robust and practical DIMs can be manufactured, they have great potential due to their thermal insulation regulating abilities.

Thermal and acoustic performance evaluation of 3D-Printable PLA materials

Hazard evaluation of indoor environment based on long-term pollutant emission characteristics of building insulation materials: An empirical study

Traditional, state-of-the-art and renewable thermal building insulation materials: An overview

A fabrication of universal multifunctional coating with excellent adhesion on the surface of solid rocket motor insulation materials through a surface activation strategy based on multiple interaction forces

The scope of our research was to evaluate the potential of the content of fibre and shives in the biomass of industrial hemp cultivars grown under different nitrogen fertiliser rates to use them for increasing the energy efficiency as a thermal insulation and acoustic material. The aim of the research was to find out the production technology, properties of the thermal conductivity for lightweight concrete made from hemp shives and sapropel or gypsum as a binder to be used for thermal and sound insulation material. The hemp cultivar 'Bialobrzeskie' was used for lightweight composite materials and lightweight composite materials were obtained with hemp shive additives with heat transfer coefficient 0.046÷0.15 W mK-1 and sound insulation index R`=35 dB. The obtained composite materials can be used as sound and heat insulation materials for building envelope in residential buildings, office buildings and factories.

Purpose. The article studies physico-chemical and thermal transformations of mineral wool thermal insulation of natural ageing. The subject of the study is thermal insulation materials of natural ageing, and the object of the study is their physicochemical and thermal characteristics. The aim of the work is to establish physicochemical and thermal transformations of mineral thermal insulation of natural ageing. The research is aimed at identifying features of physico-chemical and thermal transformations of thermal insulation based on mineral fibers and organic binders in the ageing process. Methods. A set of precision physicochemical methods such as X-ray phase analysis (XRF), infrared spectroscopy and thermal analysis methods (TG, DTG, DSC) was used. Findings. The results of studying mineral thermal insulation (service life of 60 years) revealed characteristic changes in the structure of the material. The XRF method established that the ageing process of mineral wool materials is caused by occurring microdefects and disruption of material fibers structure organization. Changes in thermal insulation phase state have thermal fluctuation of kinetic nature of material mechanical destruction. The IR spectroscopy method identified changes in the areas of characteristic absorption bands: 2 800–2 200, 2 000–1 600 and 1 295–1 005 cm–1 caused by chemical destruction of organic binder in mineral thermal insulation. The nature of thermal transformations of the material was established, a tendency towards a decrease in the threshold temperatures for mass loss start due to destructing polymer binder was revealed. It is noted that natural ageing may result in loss of fire resistance of thermal insulation systems, as well as in intensificating smoldering combustion of thermal insulation. Research application field. The results are of interest to builders, designers, fire safety engineers and can be used in regulatory and technical as well as in reference literature on fire safety. Conclusions. During the ageing process irreversible physical and chemical changes occur in the structure of thermal insulation, leading to loss of thermal stability of the material and to a possible increase in the intensity of latent smoldering combustion. Technical obsolescence of the material leads to decreasing fire resistance limits of various thermal insulation systems due to loss of thermal insulation capacity and integrity.

Current conventional cool boxes which use expanded polystyrene (EPS) as its insulating material cannot seem to maintain storage at low temperature for long periods. This study aims to determine the effect for different types of insulating materials which can be used in cool boxes to improve its thermal insulation. Using theoretical and simulation approach, three out of six potential insulating materials were chosen in terms of their heat transfer rate, and temperature at the outer wall. The three best insulating materials, polyurethane (PU), expanded polystyrene (EPS) and poly-glass fibre (PGF) were then tested at three different room temperatures experimentally using the thermal insulation test to determine the best insulating material for a cool box. Tensile and density were also conducted to identify the mechanical behaviour and properties of these insulating materials. From the results obtained from the experiment, polyurethane (PU) recorded the longest time taken for ice to change into water at the three different temperatures when compared to other insulating materials. The results showed that when thermal conductivity is low, the heat transferred through the walls of the cool box was also low thus resulting in better thermal insulation of the cool box. This study gives a better understanding in term of thermal insulation and the results obtained from this study can help with the production of better cool boxes with improved thermal insulation.

Experimental assessment of the water content influence on thermo-acoustic performance of building insulation materials

The current development of global warming and CO2 emission problems cannot be overlooked. Thus, global scale measures of efforts are becoming crucial. Thermal properties of insulation materials need to be considered as high performance thermal insulation systems are crucial for efficient energy saving. The most important parameter as indicator of a thermal insulation material is the effective thermal conductivity, but elements that affect the thermal insulation performance are rather complicated. Generally, conduction and radiation heat transfer are needed to be separately considered in precisely evaluating the thermal insulation performance as they coexist in the heat transfer process inside a multilayer insulation system. In this paper, numerical analysis of a complete diffusive enclosure model as a thermal insulation is observed to investigate the radiation effects by its dispersive heat transfer mechanisms. View factor of each relatively large dispersed material is derived in the enclosure model, where it is applicable to various shapes and any particular arrangements of dispersed materials. As this paper is the first part of a three-part working research paper, numerical analysis in this paper is carried out by assuming that the medium within the space inside the insulation system is taken to be nonparticipating, therefore conduction and convection effects during the heat exchange are negligible. This paper will be continued with application of the numerical analysis in observing radiation heating effects by wall-ceiling integration towards indoor environment and radiation–conduction heat transfer mechanisms in one-dimensional multilayer insulation system.

This article described the technical progress of the wall insulation organic materials and analyzed other relevant factors in recent years about the insulation materials policies changes and market changes. Through the above description and analysis, we presented new ideas of the future direction of development of organic insulation materials. Background In recent years, big fire moments remind the importance of fire safety all the time. The CCTV Building Fire in 2009, Shanghai Jiaozhou Road Fire in 2010 and Shijingshan Fire in 2013, let the public turn pale at the mention of a word about fire. These fires are all related to the wall insulation organic materials. In fact, it should be said that unqualified exterior wall thermal insulation materials and the lack of supervision measures led to a variety of fire accidents which can be avoided. Therefore, good flame retardant wall insulation organic materials and thermal insulation system are very important to reduce and prevent fire, and they are also fundamentally important ways to block and reduce the fire risk. At present, there are three kinds of wall insulation materials. The first type are the inorganic heat preservation materials, such as rock wool, glass wool, mineral slurry, etc., These materials belong to no combustible materials (class A fire), and there is no fire safety problems. The second type of wall insulation materials are composite materials, such as phenolic foam insulation materials, reaching flame retardant materials B1 level (fire). The third kind are the organic polymer insulation materials, such as molding benzene board (EPS), foaming benzene board (XPS), polyurethane (PU) . They belong to the combustible materials (B2 fire). This kind of material have the danger of fire. In our country the most widely used of wall insulation materials are the third class. Especially the EPS and XPS have good heat preservation performance, low price. And They are light and durable. But, this kind of materials have obvious disadvantages that they are so easy to burn, and release diffuse toxic or harmful gas in the combustion. Therefore, we should focus on hot spots about organic fire situation of wall insulation organic materials. Fire prevention progress of common wall insulation organic materials Polyurethane (PU) :

The impact of the thermal conductivity (k-value) change of polystyrene insulation material in building envelope due to changes in temperature on the thermal and energy performance of a typical residential building under hot climate is investigated. Indeed, the thermal and energy performance of buildings depends on the thermal characteristics of the building envelope, and particularly on the thermal resistance of the insulation material used. The thermal insulation material which is determined by its thermal conductivity, which describes the ability of heat to flow cross the material in presence of a gradient of temperature, is the main key to assess the performance of the thermal insulation material. When performing the energy analysis or calculating the cooling load for buildings, we use published values of thermal conductivity of insulation materials, which are normally evaluated at 24°C according to the ASTM standards. In reality, thermal insulation in building is exposed to significant and continuous temperature variations, due essentially to the change of outdoor air temperature and solar radiation. Many types of insulation materials are produced and used in Oman, but not enough information is available to evaluate their performance under the prevailing climatic condition. The main objective of this study is to investigate the relationship between the temperature and thermal conductivity of various densities of polystyrene, which is widely used as building insulation material in Oman. Moreover, the impact of thermal conductivity variation with temperature on the envelope-induced cooling load for a simple building model is discussed. This work will serve as a platform to investigate the effect of the operating temperature on thermal conductivity of other building material insulations, and leads to more accurate assessment of the thermal and energy performance of buildings in Oman.

In order to improve the steam pipe insulation material joints, waterproof, and other shortcomings, and provide a good design scheme for the insulation structure optimization, a gel heat preservation material was prepared through hydration hardening theory. Firstly, the preparation of thermal insulation material for steam pipe and the optimal design of thermal insulation structure was introduced. Then the performance of the insulation material of the steam pipe was evaluated. Finally, the stability and energy benefit of the thermal insulation structure were evaluated. The results show that the new gel thermal insulation material prepared in this research has good thermal insulation effect and good waterproof performance. In the stability evaluation of the thermal insulation structure of the steam pipe, it can be concluded that hard thermal insulation materials should be selected in the selection of thermal insulation materials. Its insulation effect is better than soft insulation material. In the thermal energy storage optimization of the thermal insulation structure, when the inner layer of the thermal insulation structure adopts 10 mm aerogel and the outer layer adopts 50 mm gel thermal insulation material, it is the optimal thermal insulation structure. The study has a good guiding effect on the economic benefit of steam pipe insulation structure.