Analysis on the Selection of Low Temperature Resistant Materials for Electric Equipment State Monitoring Device in Cold Areas

2020 ◽  
Vol 842 ◽  
pp. 251-256
Author(s):  
Hong Da Zhang ◽  
Yue Wang ◽  
Li Wei Liu ◽  
Hai Tao Feng ◽  
Lin Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Low Temperature ◽  
High Rate ◽  
Insulation Material ◽  
Monitoring Device ◽  
State Monitoring ◽  
Steady State Method ◽  
Influence Of Temperature On ◽  
Electric Equipment ◽  
Equipment State

As the important device to perceive the operating state of grid, the condition monitoring device of electric equipment solves such problems as the high rate of false alarm and failure of device caused by the low temperature in winter of cold areas. This paper measures the thermal conductivity of such three kinds of materials as asbestos, rubber and nano porous aerogels in the temperature range of -55°C to +80°C by steady state method, and analyzes the influence of temperature on the thermal conductivity of three materials. According to the result of experiment, the thermal conductivity of nano porous aerogels is the lowest and is affected least by temperature among three kinds of materials. Nano porous aerogels apply to state monitoring device operated in cold areas; and rubber can also be used as thermal insulation material when the operating temperature is generally higher than -20°C.

Rapid Freezing of Freeze-Etch Specimens

1980 ◽  
Vol 38 ◽  
pp. 752-755
Author(s):  
A. Elgsaeter ◽  
T. Espevik ◽  
G. Kopstad
Keyword(s):  
Low Temperature ◽  
Metal Surface ◽  
Relative Velocity ◽  
Thermal Contact ◽  
High Rate ◽  
Rapid Freezing ◽  
Temperature Decrease ◽  
Freeze Etching

The importance of a high rate of temperature decrease (“rapid freezing”) when freezing specimens for freeze-etching has long been recognized1. The two basic methods for achieving rapid freezing are: 1) dropping the specimen onto a metal surface at low temperature, 2) bringing the specimen instantaneously into thermal contact with a liquid at low temperature and subsequently maintaining a high relative velocity between the liquid and the specimen. Over the last couple of years the first method has received strong renewed interest, particularily as the result of a series of important studies by Heuser and coworkers 2,3. In this paper we will compare these two freezing methods theoretically and experimentally.

Low-temperature thermal conductivity and boson peak in the glassy g-As2S3

2016 ◽  
Vol 39 (0) ◽  
pp. 66-72
Author(s):  
В. Міца ◽  
О. Фегер ◽  
С. Петрецький ◽  
Р. Голомб ◽  
В. Ткач
Keyword(s):  
Thermal Conductivity ◽  
Low Temperature ◽  
Boson Peak

scholarly journals Thermal, Physical and Mechanical Performance of Orange Peel Boards: A New Recycled Material for Building Application

2021 ◽  
Vol 13 (14) ◽  
pp. 7945
Author(s):  
Matteo Vitale ◽  
María del Mar Barbero-Barrera ◽  
Santi Maria Cascone
Keyword(s):  
Thermal Conductivity ◽  
Bending Strength ◽  
Mechanical Performance ◽  
Orange Peel ◽  
Insulation Material ◽  
Orange Peels ◽  
Orange Fruit ◽  
Citrus Waste ◽  
Absorption Thickness ◽  
Loss Of Strength

More than 124 million tons of oranges are consumed in the world annually. Transformation of orange fruit generates a huge quantity of waste, largely composed of peels. Some attempts to reuse by-products derived from citrus waste have been proposed for energy production, nutrient source or pharmaceutical, food and cosmetic industries. However, their use in the building sector had not been researched. In this study, orange peels, in five different ratios, from 100% of wet peels to 75% and from 0% of dry peels to 25%, were submitted to a thermo-compression procedure. They were evaluated according to their physical (bulk density, water absorption, thickness swelling, surface soundness and thermal conductivity) and mechanical properties (bending strength and modulus of elasticity). The results showed that orange peels can be used as thermal insulation material. The addition of dried peels makes the structure of the board heterogeneous and thus increases its porosity and causes the loss of strength. Hence, the board with the sole use of wet peel, whose thermal conductivity is 0.065 W/mK while flexural strength is 0.09 MPa, is recommended.

Sticky thermoelectric materials for flexible thermoelectric modules to capture low-temperature waste heat

MRS Advances ◽  
2020 ◽  
Vol 5 (10) ◽  
pp. 481-487 ◽  
Author(s):  
Norifusa Satoh ◽  
Masaji Otsuka ◽  
Yasuaki Sakurai ◽  
Takeshi Asami ◽  
Yoshitsugu Goto ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Low Temperature ◽  
Waste Heat ◽  
Air Cooling ◽  
Conductive Adhesives ◽  
Hot Plate ◽  
Low Thermal Conductivity ◽  
Te Modules ◽  
P Type ◽  
Flexible Thermoelectric

ABSTRACTWe examined a working hypothesis of sticky thermoelectric (TE) materials, which is inversely designed to mass-produce flexible TE sheets with lamination or roll-to-roll processes without electric conductive adhesives. Herein, we prepared p-type and n-type sticky TE materials via mixing antimony and bismuth powders with low-volatilizable organic solvents to achieve a low thermal conductivity. Since the sticky TE materials are additionally injected into punched polymer sheets to contact with the upper and bottom electrodes in the fabrication process, the sticky TE modules of ca. 2.4 mm in thickness maintained temperature differences of ca. 10°C and 40°C on a hot plate of 40 °C and 120°C under a natural-air cooling condition with a fin. In the single-cell resistance analysis, we found that 75∼150-µm bismuth powder shows lower resistance than the smaller-sized one due to the fewer number of particle-particle interfaces in the electric pass between the upper and bottom electrodes. After adjusting the printed wiring pattern for the upper and bottom electrodes, we achieved 42 mV on a hot plate (120°C) with the 6 x 6 module having 212 Ω in the total resistance. In addition to the possibility of mass production at a reasonable cost, the sticky TE materials provide a low thermal conductivity for flexible TE modules to capture low-temperature waste heat under natural-air cooling conditions with fins for the purpose of energy harvesting.

A Setup for Studying the Low-Temperature Thermal Conductivity of Powder Samples

2005 ◽  
Vol 48 (3) ◽  
pp. 417-421 ◽  
Author(s):  
A. I. Krivchikov ◽  
B. Ya. Gorodilov ◽  
O. A. Korolyuk
Keyword(s):  
Thermal Conductivity ◽  
Low Temperature ◽  
Powder Samples

Structural order in alkali-degraded PAN as seen in studies of low-temperature thermal conductivity

Polymer ◽  
1983 ◽  
Vol 24 (3) ◽  
pp. 258-262 ◽  
Author(s):  
N.S. Batty ◽  
A.J. Gradwell ◽  
J.T. Guthrie ◽  
D. Greig ◽  
N.D. Hardy ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Low Temperature ◽  
Structural Order
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