P. Dou, T. Jia, Peng Chu, Yanjun Dai, Chunhui Shou
Solution transportation absorption systems are restricted by main defects of high heat source temperature demand and inflexible working pressures which are determined by the condensation temperature. Absorption-resorption heat pump cycles stand out in significantly lowering the demand of heat source temperature as well as multiplying working pressure choices and simplifying system structure. In this paper, a novel solution transportation resorption system is proposed based on the single-stage ARHP cycle. Feasible working pressure combinations and outlet temperature of high pressure-absorber to effect the system are investigated, illustrating the pressure range difference between ARHP and ARHP-based STR system. Thermodynamic parameters such as thermal coefficient of performance, electrical coefficient of performance, heat supply temperature range are revealed by comparing with those of single-stage ARHP cycle. Under the condition that transporting distance is 20 km, maximum COP value of STR system could reach 0.53 when P H / P L value is 700 kPa /405 kPa. The highest supply water temperature could reach 53.84 o C with COP of 0.477. The longest distance is supposed to be no more than 113 km when loading power is 20 MW.
溶液输送吸收系统的主要缺陷是热源温度要求高和冷凝温度决定的工作压力不灵活。吸收-再吸收热泵循环在显著降低热源温度需求、增加工作压力选择和简化系统结构方面表现突出。本文提出了一种基于单级ARHP循环的新型溶液输送吸收系统。研究了影响系统的可行工作压力组合和高压吸收器出口温度，说明了ARHP和基于ARHP的STR系统的压力范围差异。通过与单级ARHP循环的比较，揭示了热工性能系数、电学性能系数、供热温度范围等热力学参数。在输运距离为20 km的条件下，当P H / P L值为700 kPa /405 kPa时，STR系统COP值最大可达0.53。供水温度最高可达53.84℃，COP为0.477。负载功率为20mw时，最长距离不超过113公里。
{"title":"Performance Analysis of No-Insulation Long Distance Thermal Transportation System Based on Single-Stage Absorption-Resorption Cycle","authors":"P. Dou, T. Jia, Peng Chu, Yanjun Dai, Chunhui Shou","doi":"10.2139/ssrn.3886308","DOIUrl":"https://doi.org/10.2139/ssrn.3886308","url":null,"abstract":"Solution transportation absorption systems are restricted by main defects of high heat source temperature demand and inflexible working pressures which are determined by the condensation temperature. Absorption-resorption heat pump cycles stand out in significantly lowering the demand of heat source temperature as well as multiplying working pressure choices and simplifying system structure. In this paper, a novel solution transportation resorption system is proposed based on the single-stage ARHP cycle. Feasible working pressure combinations and outlet temperature of high pressure-absorber to effect the system are investigated, illustrating the pressure range difference between ARHP and ARHP-based STR system. Thermodynamic parameters such as thermal coefficient of performance, electrical coefficient of performance, heat supply temperature range are revealed by comparing with those of single-stage ARHP cycle. Under the condition that transporting distance is 20 km, maximum COP value of STR system could reach 0.53 when P H / P L value is 700 kPa /405 kPa. The highest supply water temperature could reach 53.84 o C with COP of 0.477. The longest distance is supposed to be no more than 113 km when loading power is 20 MW.","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128803285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-21DOI: 10.15587/1729-4061.2020.217970
Y. Tsapko, I. Rogovskii, L. Titova, R. Shatrov, А. Tsapko, O. Bondarenko, S. Mazurchuk
The conducted studies of the impact of thermal action of a high-temperature magnesium flame on construction materials for timber protection from atmospheric factors revealed a pattern of temperature transfer to timber. It was proved that depending on the thermophysical properties of the material, this can lead to its ignition or slowing down the thermal conductivity process. That is why there arises the need to study the conditions for thermal conductivity and establish the mechanism for inhibition of heat transfer to timber. In this regard, a mathematical model of the process of transferring heat flow on the surface of timber when protected by coatings was developed. According to the experimental data and obtained dependences, it was established that the density of heat flow through a steel plate increases to a value of more than 200 kW/m2, which is sufficient for ignition of timber. Instead, the density of heat flow through a vermiculite plate did not exceed 5.2 kW/m2, which is not enough for its ignition. It was established that the main regulator of the heat transfer process is the heat-insulating properties of a construction product, its resistance to high temperature, because certain construction products, such as an asbestos-cement product, are destroyed under the influence of magnesium flame. That is why a significant impact on the process of protection of natural combustible material when applying the protective coating is made in the direction of heat insulation of the timber surface. This makes it possible to argue about the relevance of the detected mechanism of the formation of heat-insulating properties when it comes to the protection of storage sites of explosive products and the practical attractiveness of the proposed technological solutions. Thus, the features of inhibiting the process of transferring heat to timber during the action of the magnesium flame include heat insulation of timber surfaces by thermally resistant material. Thus, the temperature of a magnesium flame was created on the vermiculate surface, and it did not exceed 100 °C on the surface of the timber
{"title":"Establishing Patterns of Heat Transfer to Timber Through a Protective Structure","authors":"Y. Tsapko, I. Rogovskii, L. Titova, R. Shatrov, А. Tsapko, O. Bondarenko, S. Mazurchuk","doi":"10.15587/1729-4061.2020.217970","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.217970","url":null,"abstract":"The conducted studies of the impact of thermal action of a high-temperature magnesium flame on construction materials for timber protection from atmospheric factors revealed a pattern of temperature transfer to timber. It was proved that depending on the thermophysical properties of the material, this can lead to its ignition or slowing down the thermal conductivity process. That is why there arises the need to study the conditions for thermal conductivity and establish the mechanism for inhibition of heat transfer to timber. In this regard, a mathematical model of the process of transferring heat flow on the surface of timber when protected by coatings was developed. According to the experimental data and obtained dependences, it was established that the density of heat flow through a steel plate increases to a value of more than 200 kW/m2, which is sufficient for ignition of timber. Instead, the density of heat flow through a vermiculite plate did not exceed 5.2 kW/m2, which is not enough for its ignition. It was established that the main regulator of the heat transfer process is the heat-insulating properties of a construction product, its resistance to high temperature, because certain construction products, such as an asbestos-cement product, are destroyed under the influence of magnesium flame. That is why a significant impact on the process of protection of natural combustible material when applying the protective coating is made in the direction of heat insulation of the timber surface. This makes it possible to argue about the relevance of the detected mechanism of the formation of heat-insulating properties when it comes to the protection of storage sites of explosive products and the practical attractiveness of the proposed technological solutions. Thus, the features of inhibiting the process of transferring heat to timber during the action of the magnesium flame include heat insulation of timber surfaces by thermally resistant material. Thus, the temperature of a magnesium flame was created on the vermiculate surface, and it did not exceed 100 °C on the surface of the timber","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114684059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ehud Almog, V. Derkach, Amit L. Sharma, A. Novick-Cohen, J. Greer, E. Rabkin
Abstract Thin metal films deposited on patterned or rough substrates play an increasing role in microelectronics, sensing, catalysis, and other areas of nanotechnology. However, the thermal stability and solid state dewetting of thin metal films with complex three-dimensional architecture is still poorly understood. In this work we employed a model system of nanocrystalline Au thin films deposited on prismatic single crystalline KCl whiskers to study the solid state dewetting of thin films in a three-dimensional setting. The arrays of KCl whiskers were grown on porous substrates under well-defined humidity and temperature conditions. Single crystalline prismatic KCl whiskers with a very high aspect ratio, [001] axis and {100} side facets were obtained. The whiskers were coated with thin conformal Au films of 20-30 nm in thickness. The annealing of these core-shell whiskers at the temperature of 350oC resulted in solid state dewetting of the Au film, with the dewetting processes occurring much faster along the whisker edges than on the side facets. The orientation relationships between Au and KCl were determined by employing similarly prepared thin Au films deposited on the flat KCl (100) substrates. Inspired by our experimental results, we developed a numerical model describing the curvature-gradient driven and surface diffusion-controlled growth of a hole in the thin film deposited on a curved substrate. The model predicted the growth of anisotropic elliptical holes elongated along the whisker axis. We discuss the experimental results in terms of the proposed model, indicating the importance of the change in orientation relationship between the Au grains and KCl whisker along the whisker edges.
{"title":"Thermal Stability of Thin AU Films Deposited on Salt Whiskers","authors":"Ehud Almog, V. Derkach, Amit L. Sharma, A. Novick-Cohen, J. Greer, E. Rabkin","doi":"10.2139/ssrn.3680401","DOIUrl":"https://doi.org/10.2139/ssrn.3680401","url":null,"abstract":"Abstract Thin metal films deposited on patterned or rough substrates play an increasing role in microelectronics, sensing, catalysis, and other areas of nanotechnology. However, the thermal stability and solid state dewetting of thin metal films with complex three-dimensional architecture is still poorly understood. In this work we employed a model system of nanocrystalline Au thin films deposited on prismatic single crystalline KCl whiskers to study the solid state dewetting of thin films in a three-dimensional setting. The arrays of KCl whiskers were grown on porous substrates under well-defined humidity and temperature conditions. Single crystalline prismatic KCl whiskers with a very high aspect ratio, [001] axis and {100} side facets were obtained. The whiskers were coated with thin conformal Au films of 20-30 nm in thickness. The annealing of these core-shell whiskers at the temperature of 350oC resulted in solid state dewetting of the Au film, with the dewetting processes occurring much faster along the whisker edges than on the side facets. The orientation relationships between Au and KCl were determined by employing similarly prepared thin Au films deposited on the flat KCl (100) substrates. Inspired by our experimental results, we developed a numerical model describing the curvature-gradient driven and surface diffusion-controlled growth of a hole in the thin film deposited on a curved substrate. The model predicted the growth of anisotropic elliptical holes elongated along the whisker axis. We discuss the experimental results in terms of the proposed model, indicating the importance of the change in orientation relationship between the Au grains and KCl whisker along the whisker edges.","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129366373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Sarkar, D. Shinde, A. Das, D. Ray, D. Sen, A. Biswas
In this work, spinodal decomposition (SD) in Fe-35 at.% Cr alloy is quantified by correlatively combining two complimentary techniques namely, Atom Probe Tomography (APT) and Small Angle Neutron Scattering (SANS). In order to overcome the uncertainty often encountered in quantification of the characteristic SD parameters (wavelength λSD , amplitude A and volume fraction of Cr-rich α/ -phase Φ), we adopt the following: (i) utilize the unique specific attribute of a technique suitable for evaluating any particular SD parameter; (ii) incorporate such reliably extracted parameter as input for evaluating other parameters wherever applicable. This novel correlative approach builds on each other’s strength and provides improved accuracy. λSD is determined independently from APT and SANS analyses. For evaluation of A and Φ, APT analysis utilizes the value of λSD determined from SANS, whereas the phase compositions evaluated by APT are utilized in SANS analysis. With progressive phase separation, α/α/ compositional difference increases continually (from 19.8% after 10 h to 48.2% after 500 h) along with concomitant contraction of the interface (from 1.92 nm to 1.55 nm), underscoring the distinctive characteristics of SD process. Signature of rarely observed early stage of phase separation in the form of a dense population (9.78x1024 /m3 ) of extremely small (0.67 nm radius) Cr-rich nanoclusters is registered after aging only for 1 h. In addition, temporal evolution of λSD clearly distinguishes early stage of SD (time exponent of 0.15) from the coarsening stage (time exponent of 0.29, 120 h onwards).
{"title":"Quantitative Evaluation of Spinodal Decomposition in Thermally Aged Binary Fe-35 At.% Cr Alloys by Correlative APT and SANS Analyses","authors":"S. Sarkar, D. Shinde, A. Das, D. Ray, D. Sen, A. Biswas","doi":"10.2139/ssrn.3693559","DOIUrl":"https://doi.org/10.2139/ssrn.3693559","url":null,"abstract":"In this work, spinodal decomposition (SD) in Fe-35 at.% Cr alloy is quantified by correlatively combining two complimentary techniques namely, Atom Probe Tomography (APT) and Small Angle Neutron Scattering (SANS). In order to overcome the uncertainty often encountered in quantification of the characteristic SD parameters (wavelength λSD , amplitude A and volume fraction of Cr-rich α/ -phase Φ), we adopt the following: (i) utilize the unique specific attribute of a technique suitable for evaluating any particular SD parameter; (ii) incorporate such reliably extracted parameter as input for evaluating other parameters wherever applicable. This novel correlative approach builds on each other’s strength and provides improved accuracy. λSD is determined independently from APT and SANS analyses. For evaluation of A and Φ, APT analysis utilizes the value of λSD determined from SANS, whereas the phase compositions evaluated by APT are utilized in SANS analysis. With progressive phase separation, α/α/ compositional difference increases continually (from 19.8% after 10 h to 48.2% after 500 h) along with concomitant contraction of the interface (from 1.92 nm to 1.55 nm), underscoring the distinctive characteristics of SD process. Signature of rarely observed early stage of phase separation in the form of a dense population (9.78x1024 /m3 ) of extremely small (0.67 nm radius) Cr-rich nanoclusters is registered after aging only for 1 h. In addition, temporal evolution of λSD clearly distinguishes early stage of SD (time exponent of 0.15) from the coarsening stage (time exponent of 0.29, 120 h onwards).","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131112520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thermal cycling creep behaviors of Ni-based alloy DZ125 have been studied by means of tests with different stress, overheating duration and temperature. The test results revealed that thermal cycling creep with short overheating duration will offset alloys’ thermal equilibrium state. The decrease on creep resistance of materials suffering thermal cycling creep is analyzed from a microstructure perspective. A phenomenological relationship between overheating number and microstructure evolution has been revealed. Furthermore, an efficient life prediction method specifically for thermal cycling creep was firstly proposed in this research with satisfying accuracy.
{"title":"Creep Behavior of a Nickel-Based Superalloy Under Cyclic Temperatures","authors":"Qiang Zhang, Yun-Chen Jiang, Xiaoan Hua, Yantao Sun, Shengliang Zhang, Xiaoguang Yang","doi":"10.2139/ssrn.3688749","DOIUrl":"https://doi.org/10.2139/ssrn.3688749","url":null,"abstract":"Thermal cycling creep behaviors of Ni-based alloy DZ125 have been studied by means of tests with different stress, overheating duration and temperature. The test results revealed that thermal cycling creep with short overheating duration will offset alloys’ thermal equilibrium state. The decrease on creep resistance of materials suffering thermal cycling creep is analyzed from a microstructure perspective. A phenomenological relationship between overheating number and microstructure evolution has been revealed. Furthermore, an efficient life prediction method specifically for thermal cycling creep was firstly proposed in this research with satisfying accuracy.","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124508916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-08-25DOI: 10.15587/1729-4061.2020.210009
Y. Tsapko, V. Lomaha, А. Tsapko, S. Mazurchuk, O. Horbachova, D. Zavialov
An analysis of fire-retardant materials for wooden building structures is carried out and the need to develop reliable methods for studying the process of ignition and flame propagation on the surface of a building structure, necessary for creating new types of fire-retardant materials, is found. Therefore, it is necessary to determine the conditions for forming a thermal conductivity barrier and find a mechanism for inhibiting heat transfer to the material. In this regard, a computational and analytical method for determining thermal conductivity when using a fire-retardant varnish as a coating is developed, which allows assessing the coefficient of thermal conductivity under high temperature action. According to experimental data and theoretical dependences, the coefficient of thermal conductivity of the fire-retardant coked foam layer of 0.36 W/(m∙K) is calculated, which, accordingly, ensures the heat resistance of wood. As a result of research, it is proved that the process of heat insulation of a wooden structure consists in the formation of soot-like products on the surface of natural combustible material. This made it possible to determine the conditions for fireproofing wood by forming a thermal conductivity barrier during the decomposition of varnish into foamed coke. Experimental studies confirmed that a sample of fireproof wood withstood the temperature effect of the heat flux for 900 s. The maximum possible temperature penetration through the coating is evaluated. It is found that under the temperature effect on the sample, which significantly exceeds the ignition temperature of wood, on the unheated surface of the sample, this value did not exceed 180 °C. Thus, there is reason to assert the possibility of directional regulation of wood fire protection processes using fire-retardant coatings that can form a protective layer on the material surface that inhibits wood burnout
{"title":"Determination of Regularities of Heat Resistance Under Flame Action on Wood Wall With Fire-Retardant Varnish","authors":"Y. Tsapko, V. Lomaha, А. Tsapko, S. Mazurchuk, O. Horbachova, D. Zavialov","doi":"10.15587/1729-4061.2020.210009","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.210009","url":null,"abstract":"An analysis of fire-retardant materials for wooden building structures is carried out and the need to develop reliable methods for studying the process of ignition and flame propagation on the surface of a building structure, necessary for creating new types of fire-retardant materials, is found. Therefore, it is necessary to determine the conditions for forming a thermal conductivity barrier and find a mechanism for inhibiting heat transfer to the material. In this regard, a computational and analytical method for determining thermal conductivity when using a fire-retardant varnish as a coating is developed, which allows assessing the coefficient of thermal conductivity under high temperature action. According to experimental data and theoretical dependences, the coefficient of thermal conductivity of the fire-retardant coked foam layer of 0.36 W/(m∙K) is calculated, which, accordingly, ensures the heat resistance of wood. As a result of research, it is proved that the process of heat insulation of a wooden structure consists in the formation of soot-like products on the surface of natural combustible material. This made it possible to determine the conditions for fireproofing wood by forming a thermal conductivity barrier during the decomposition of varnish into foamed coke. Experimental studies confirmed that a sample of fireproof wood withstood the temperature effect of the heat flux for 900 s. The maximum possible temperature penetration through the coating is evaluated. It is found that under the temperature effect on the sample, which significantly exceeds the ignition temperature of wood, on the unheated surface of the sample, this value did not exceed 180 °C. Thus, there is reason to assert the possibility of directional regulation of wood fire protection processes using fire-retardant coatings that can form a protective layer on the material surface that inhibits wood burnout","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"2018 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115453357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Cubic boron compounds (c-BN, c-BP, and c-BAs) are emerging semiconductor materials with extraordinary chemical and physical properties, e.g., record-high thermal conductivity. Because of these, they have attracted increased interest for applications in heat management and electronics. However, many fundamental properties especially for c-BP and c-BAs remain poorly understood. Herein, we report a systematic first-principles study of the important physical properties of boron compounds, including elastic constants, mechanical properties, and deformation behavior under tensile and shearing (pure shear and Vickers indentation shear) loads. The stress-strain relations show isotropic elastic behavior at a small strain and strong anisotropic responses with varied peak stresses along different tensile direction and shear system at a larger strain. In particular, we observe a large disparity between the tensile and shear strengths for c-BP and c-BAs due to shearing load-induced metallization and phonon softening. We examine the deformation process in terms of bond-breaking to understand the microscopic origin and impact on the strength of the materials. We show that both c-BP and c-BAs are not superhard materials but they offer a balance between hardness, synthesis, and sustainability that has been an issue for both c-BN and diamond for applications.
{"title":"Mechanical Properties and Hardness of Boron Pnicogens Bx (X = N, P, As)","authors":"C. Ekuma, Z. Liu","doi":"10.2139/ssrn.3649262","DOIUrl":"https://doi.org/10.2139/ssrn.3649262","url":null,"abstract":"Abstract Cubic boron compounds (c-BN, c-BP, and c-BAs) are emerging semiconductor materials with extraordinary chemical and physical properties, e.g., record-high thermal conductivity. Because of these, they have attracted increased interest for applications in heat management and electronics. However, many fundamental properties especially for c-BP and c-BAs remain poorly understood. Herein, we report a systematic first-principles study of the important physical properties of boron compounds, including elastic constants, mechanical properties, and deformation behavior under tensile and shearing (pure shear and Vickers indentation shear) loads. The stress-strain relations show isotropic elastic behavior at a small strain and strong anisotropic responses with varied peak stresses along different tensile direction and shear system at a larger strain. In particular, we observe a large disparity between the tensile and shear strengths for c-BP and c-BAs due to shearing load-induced metallization and phonon softening. We examine the deformation process in terms of bond-breaking to understand the microscopic origin and impact on the strength of the materials. We show that both c-BP and c-BAs are not superhard materials but they offer a balance between hardness, synthesis, and sustainability that has been an issue for both c-BN and diamond for applications.","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125119806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-05DOI: 10.35940/ijeat.d8060.049420
Manoj Modi
The friction and friction factors are critical factors in flow through pipes, and heat ex-changer etc. The minimal friction is not only beneficial for pumping cost perspective, but also it reduces the loss of energy. All experimental tests were performed in accordance to Taguchi L9 orthogonal array on cast iron, aluminum, and copper pipes to study the effect of variations of viscosity, flow rates, and pipe materials on the friction factor.
{"title":"Influence of Viscosity Variation on Coefficient of Friction in Pipe Flow with Different Pipe Materials and Flow Rates using Taguchi Design Method","authors":"Manoj Modi","doi":"10.35940/ijeat.d8060.049420","DOIUrl":"https://doi.org/10.35940/ijeat.d8060.049420","url":null,"abstract":"The friction and friction factors are critical factors in flow through pipes, and heat ex-changer etc. The minimal friction is not only beneficial for pumping cost perspective, but also it reduces the loss of energy. All experimental tests were performed in accordance to Taguchi L9 orthogonal array on cast iron, aluminum, and copper pipes to study the effect of variations of viscosity, flow rates, and pipe materials on the friction factor.<br>","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134374514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-30DOI: 10.15587/1729-4061.2020.200467
Y. Tsapko, А. Tsapko, O. Bondarenko
The creation of environmentally safe fire-retardant materials for wooden building structures will allow influencing the processes of heat resistance and physicochemical properties of the protective coating during its service life. Therefore, there is a need to study the conditions for forming a barrier to thermal conductivity and determine a mechanism of inhibiting heat transfer to the material. In this regard, a mathematical model of the thermal conductivity process when using fire-retardant fabric as a coating is developed, the solution of which allows obtaining changes in the thermal conductivity of the material. According to experimental data, it is calculated that the thermal conductivity coefficient during fire protection in the temperature range from 0 to 110 °C increases due to water evaporation and then gradually decreases to 0.25 W/(m∙°С), which corresponds to the value of coked foam. It is proved that the process of temperature inhibition consists in the formation of soot-like products that insulate the wooden structure. This made it possible to determine the conditions of fire protection of wood, formation of a barrier to thermal conductivity using fire-retardant fabric. Experimental studies confirmed that the wood sample with fire-retardant fabric withstood the temperature effect, namely, under the influence of the heat flux, the coating swelled, heat insulation continued for 900 s. Estimation of the maximum possible temperature penetration through the coating is carried out. It is found that when creating the sample surface temperature, which significantly exceeded the ignition temperature of wood, the temperature under the fabric did not reach the ignition temperature, and on the unheated surface it did not exceed 100 °C. Thus, there are reasons to argue about the possibility of directed control of the processes of wood fire protection using fire-retardant coatings capable of forming a protective layer on the material surface, which reduces the burnout rate of wood
{"title":"Determination of the Laws of Thermal Resistance of Wood in Application of Fire-Retardant Fabric Coatings","authors":"Y. Tsapko, А. Tsapko, O. Bondarenko","doi":"10.15587/1729-4061.2020.200467","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.200467","url":null,"abstract":"The creation of environmentally safe fire-retardant materials for wooden building structures will allow influencing the processes of heat resistance and physicochemical properties of the protective coating during its service life. Therefore, there is a need to study the conditions for forming a barrier to thermal conductivity and determine a mechanism of inhibiting heat transfer to the material. In this regard, a mathematical model of the thermal conductivity process when using fire-retardant fabric as a coating is developed, the solution of which allows obtaining changes in the thermal conductivity of the material. According to experimental data, it is calculated that the thermal conductivity coefficient during fire protection in the temperature range from 0 to 110 °C increases due to water evaporation and then gradually decreases to 0.25 W/(m∙°С), which corresponds to the value of coked foam. It is proved that the process of temperature inhibition consists in the formation of soot-like products that insulate the wooden structure. This made it possible to determine the conditions of fire protection of wood, formation of a barrier to thermal conductivity using fire-retardant fabric. Experimental studies confirmed that the wood sample with fire-retardant fabric withstood the temperature effect, namely, under the influence of the heat flux, the coating swelled, heat insulation continued for 900 s. Estimation of the maximum possible temperature penetration through the coating is carried out. It is found that when creating the sample surface temperature, which significantly exceeded the ignition temperature of wood, the temperature under the fabric did not reach the ignition temperature, and on the unheated surface it did not exceed 100 °C. Thus, there are reasons to argue about the possibility of directed control of the processes of wood fire protection using fire-retardant coatings capable of forming a protective layer on the material surface, which reduces the burnout rate of wood","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126715822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Parida, Meinam Annebushan Singh, Kali Charan Ratha
In the past few decades, a lot of experiments had been done to identify the thermal conductivity of particulate filled polymer composites. The trend had resulted in creation of increased thermal and mechanical properties particulate composites. In the present research work, the thermal conductivity of aluminium filled polymer composite was identified by three way approach, viz, experimental, analytical and finally by FEM – Ansys. Various filler concentration was taken and the thermal conductivity was identified for each unique case and the values were further compared with other methods for verifying the experimental data. The analysis shows that addition of aluminium particulates increases the thermal conductivity of the composites, thereby improving its heat transfer capability.
{"title":"Thermal Analysis of Particulate Filled Polymer Composite","authors":"N. Parida, Meinam Annebushan Singh, Kali Charan Ratha","doi":"10.2139/ssrn.3584977","DOIUrl":"https://doi.org/10.2139/ssrn.3584977","url":null,"abstract":"In the past few decades, a lot of experiments had been done to identify the thermal conductivity of particulate filled polymer composites. The trend had resulted in creation of increased thermal and mechanical properties particulate composites. In the present research work, the thermal conductivity of aluminium filled polymer composite was identified by three way approach, viz, experimental, analytical and finally by FEM – Ansys. Various filler concentration was taken and the thermal conductivity was identified for each unique case and the values were further compared with other methods for verifying the experimental data. The analysis shows that addition of aluminium particulates increases the thermal conductivity of the composites, thereby improving its heat transfer capability.","PeriodicalId":256429,"journal":{"name":"EngRN: Thermal Engineering (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129590217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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