Inga Zotova^1,*, Edgars Kirilovs¹, Laura Ziemele²

Journal of Renewable Materials, Vol.12, No.3, pp. 603-613, 2024, DOI:10.32604/jrm.2024.047607

Abstract Nowadays buildings contain innovative materials, materials from local resources, production surpluses and rapidly renewable natural resources. Phase Change Materials (PCM) are one such group of novel materials which reduce building energy consumption. With the wider availability of microencapsulated PCM, there is an opportunity to develop a new type of insulating materials, combinate PCM with traditional insulation materials for latent heat energy storage. These materials are typically flammable and are located on the interior wall finishing yet there has been no detailed assessment of their fire performance. In this research work prototypes of low-density insulating boards for indoor spaces from hemp… More > Graphic Abstract

Laima Vevere^*, Beatrise Sture, Vladimir Yakushin, Mikelis Kirpluks, Ugis Cabulis

Journal of Renewable Materials, Vol.12, No.3, pp. 585-602, 2024, DOI:10.32604/jrm.2024.047350

Abstract Cryogenic insulation material rigid polyurethane (PU) foams were developed using bio-based and recycled feedstock. Polyols obtained from tall oil fatty acids produced as a side stream of wood biomass pulping and recycled polyethylene terephthalate were used to develop rigid PU foam formulations. The 4th generation physical blowing agents with low global warming potential and low ozone depletion potential were used to develop rigid PU foam cryogenic insulation with excellent mechanical and thermal properties. Obtained rigid PU foams had a thermal conductivity coefficient as low as 0.0171 W/m·K and an apparent density of 37–40 kg/m³. The developed rigid PU foams had… More > Graphic Abstract

Noureddine Abouricha^1,*, Ayoub Gounni², Mustapha El Alami²

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 359-375, 2024, DOI:10.32604/fhmt.2024.047632

Abstract In this paper, experimental and numerical studies of heat transfer in a test local of side heated from below are presented and compared. All the walls, the rest of the floor and the ceiling are made from plywood and polystyrene in sandwich form ( plywood- polystyrene- plywood) just on one of the vertical walls contained a glazed door (). This local is heated during two heating cycles by a square plate of iron the width , which represents the heat source, its temperature is controlled. The plate is heated for two cycles by an adjustable set-point heat source placed just… More >

Ming Liu¹, Pinghua Zhu^2,*, Xiancui Yan², Haichao Li², Xintong Chen²

Journal of Renewable Materials, Vol.12, No.2, pp. 329-347, 2024, DOI:10.32604/jrm.2023.045381

Abstract As socioeconomic development continues, the issue of building energy consumption has attracted significant attention, and improving the thermal insulation performance of buildings has become a crucial strategic measure. Simultaneously, the application of solid waste in insulation materials has also become a hot topic. This paper reviews the sources and classifications of solid waste, focusing on research progress in its application as insulation materials in the domains of daily life, agriculture, and industry. The research shows that incorporating household solid waste materials, such as waste glass, paper, and clothing scraps into cementitious thermal insulation can significantly reduce the thermal conductivity of… More >

Weijun Wang^1,*, Min Chen¹, Hui Yin¹, Yuan Li²

Energy Engineering, Vol.120, No.10, pp. 2433-2448, 2023, DOI:10.32604/ee.2023.028620

Abstract To identify the parameters of the extended Debye model of XLPE cables, and therefore evaluate the insulation performance of the samples, the sparsity-promoting dynamic mode decomposition (SPDMD) method was introduced, as well the basics and processes of its application were explained. The amplitude vector based on polarization current was first calculated. Based on the non-zero elements of the vector, the number of branches and parameters including the coefficients and time constants of each branch of the extended Debye model were derived. Further research on parameter identification of XLPE cables at different aging stages based on the SPDMD method was carried… More >

Xu Yang^1,2, Jing Zhang^1,2, Chuanxian Luo^1,2, Qinqing Huang^1,2, Hui Xu^1,2, Guozhi Zhang^1,2,*

Energy Engineering, Vol.120, No.9, pp. 2115-2132, 2023, DOI:10.32604/ee.2023.027198

Abstract In response to the problem of frequent leakage and false alarm of partial discharge insulation defects in GIS, this paper conducts experimental research on intermittent discharge characteristics of common solid insulation defects in GIS. Using true GIS to build a multi-source testing platform for intermittent discharge of solid insulation defects, and using pulse current method, ultra-high frequency method, ultrasonic method, and gas characteristic component detection method to study the variation law of intermittent discharge characteristics of solid insulation defects. The results show that: the intermittent discharge state of metal fouling defects on the solid insulation surface decreases with the extension… More >

Kevin W. Irick^*

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-7, 2017, DOI:10.5098/hmt.8.2

Abstract The Single-sided Guarded Hot Plate Method for Comparative Testing of Thermal Radiation Barriers in Vacuum was used to evaluate the performance of a variety of aerogel insulation specimens manufactured by Aspen Aerogels® against one another and against multi-layer insulation (MLI). Testing at the Air Force Research Laboratory (AFRL) shows that the effective thermal resistance, R_e, of all tested aerogel specimens are virtually bounded by the performance of 5-layer and 10-layer MLI specimens over a mean specimen temperature, T_m, range of about 270K to 315K. More >

Kevin W. Irick^a , Sally M. Smith^b , Andrew D. Williams^b,* , Derek W. Hengeveld^c , Joy M. Stein^b

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-5, 2019, DOI:10.5098/hmt.12.30

Abstract This paper provides an analysis of the thermal performance of aerogel insulation used during a long-term International Space Station (ISS) flight experiment aboard Space Test Program – Houston 3 (STP-H3). The Variable emissivity device Aerogel insulation blanket, Dual zone thermal control Experiment suite for Responsive space (VADER) investigation tested a variable emissivity radiator and a new form of multi-layer insulation that used aerogel as the thermal isolator. An effort was made to evaluate the performance of the aerogel insulation over the active flight period. The available flight temperature data shows no evidence of deterioration or change in the aerogel insulation’s… More >

B. Gangadhara Rao^a,*, K. Elangovan^b, K. Hema Chandra Reddy^a, M. Arulprakasajothi^c

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-8, 2021, DOI:10.5098/hmt.16.15

Abstract In this research, the 3-D coupled thermal electric model analyses on a sandwich bus bar are presented for the comparison of F Class & B Class of insulation. IEC defines the maximum temperature limit at the conductor based on the class of insulation. This paper gives the clarity on the variation on the current density i.e, the size of the conductor by varying the class of insulation. The study is conducted on tin plated 2000 A sandwich busbar system. The sandwich bus bar is made of copper conductors with tin plating and enclosed by an aluminum cover along its length.… More >

Li Xiao^1,2, Xu Yang^1,2,*, Guozhi Zhang^1,2, Lin Cheng^1,2, Yi Jiang^1,2, Chuanxian Luo^1,2, Jing Zhang^1,2

Energy Engineering, Vol.120, No.5, pp. 1239-1252, 2023, DOI:10.32604/ee.2023.025530

Abstract In view of the effective perception demand of PD (Partial Discharge) insulation defect of in-service GIS (Gas Insulated Switchgear), the external UHF (Ultra High Frequency, 0.3−3 GHz) sensing technology for GIS PD insulation defect from resin hole is studied in this paper. Firstly, rectangular waveguide theory is used to analyze the electromagnetic wave propagation characteristics from rectangular resin hole in GIS disc insulator. It is found that the energy of leaked electromagnetic wave mainly concentrates in the frequency band above 1 GHz. Then based on this frequency band characteristics, a cavity-backed bowtie sensor for GIS PD external detection is designed… More >