Fundamental investigation on the thermal transfer coefficient due to arc faults

2006 ◽  
Vol 34 (3) ◽  
pp. 1038-1045 ◽  
Author(s):  
Xiang Zhang ◽  
G. Pietsch ◽  
Jiaosuo Zhang ◽  
E. Gockenbach
Keyword(s):  
Transfer Coefficient ◽  
Thermal Transfer ◽  
Fundamental Investigation

Experimental Studying Nanofluid Thermal Transfer In Microchannel

2016 ◽  
Vol 11 (2) ◽  
pp. 5-11
Author(s):  
Vladimir Aniskin ◽  
Valeriy Rudyak
Keyword(s):  
Silicon Dioxide ◽  
Transfer Coefficient ◽  
Volume Fraction ◽  
Micro Channel ◽  
Thermal Transfer ◽  
Nanoparticles Volume Fraction ◽  
Inner Diameter ◽  
Average Size ◽  
Silicon Dioxide Nanoparticle ◽  
Base Liquid

In paper new setup for studying the thermal transfer of nanofluid in the steel micro-channel with inner diameter 358 microns is described. Setup testing carried out by means of known experimental data about thermal transport of the water. Then the data about the thermal tranfer coefficient of the water based nanofluids with silicon dioxide nanoparticle with average size 25 nm are discussed. It was shown that nanofluids have the thermal transfer coefficient much more than that of base liquid. The enhancement of the thermal transfer coefficient of one-percent nanofluid is about 60 %. This enhancement grows with increasing of the nanoparticles volume fraction and flow rate of the nanofluid.

Application of Double-Sided Heat Flow Meter in Testing of Overall Heat Transfer Coefficient of Building Envelope

2013 ◽  
Vol 353-356 ◽  
pp. 2872-2876
Author(s):  
Hai Rong Dong ◽  
Shao Ming Qi
Keyword(s):  
Heat Flow ◽  
Thermal Property ◽  
Transfer Coefficient ◽  
Energy Saving ◽  
Field Testing ◽  
Building Envelope ◽  
Existing Buildings ◽  
Flow Meter ◽  
Thermal Transfer ◽  
Heat Flow Meter

It is essential to find out the thermal property of building envelope in order to design economical and reasonable scheme of energy-saving reconstruction. Field testing is a method of receiving the thermal property of envelope when existing buildings are reconstructed. In this paper, we focus on the need for obtaining the thermal transfer coefficient. A methoddouble-sided heat flow meter was introduced and used to test the thermal property of wall. The testing results show that it provides a feasible method for colleting basal data of energy-saving reconstruction of existing buildings.

Structures of Aluminum Base Alloys Solidified by Vibrations

2015 ◽  
Vol 1128 ◽  
pp. 88-97 ◽  
Author(s):  
Mirela Popescu ◽  
Béla Varga
Keyword(s):  
Transfer Coefficient ◽  
Structural Changes ◽  
Mechanical Vibrations ◽  
Qualitative And Quantitative ◽  
Thermal Transfer ◽  
Casting Alloys ◽  
Cooling Intensity ◽  
Structure Improvement ◽  
Quantitative Examination ◽  
Aluminum Base

As it is known the improving of the casting alloys properties supposes both finishing and modifying their structure. Dates from castings production specify that for structure improvement the metallurgical methods are more preferred than physical ones. The study analyzes the structural changes caused by melt vibration during crystallization of hypoeutectic and eutectic silumins and of the aluminum-copper alloy. The analysis of solidification conditions was achieved by recording cooling curves, and by the qualitative and quantitative examination of the obtained structures. The monitoring of the cooling intensity with or without mechanical vibrations was performed by calculate the global thermal transfer coefficient. It was followed in the same time the influence of mechanical vibrations on the casting alloys compactity. Global thermal transfer coefficient value increased 3.5 times.

Evaporation of lignin-lean black liquor

TAPPI Journal ◽  
2015 ◽  
Vol 14 (7) ◽  
pp. 441-450
Author(s):  
HENRIK WALLMO, ◽  
ULF ANDERSSON ◽  
MATHIAS GOURDON ◽  
MARTIN WIMBY
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Black Liquor ◽  
Salt Content ◽  
Solubility Limit ◽  
Lignin Removal ◽  
Kraft Black Liquor ◽  
Black Liquors ◽  
The Heat Transfer Coefficient

Many of the pulp mill biorefinery concepts recently presented include removal of lignin from black liquor. In this work, the aim was to study how the change in liquor chemistry affected the evaporation of kraft black liquor when lignin was removed using the LignoBoost process. Lignin was removed from a softwood kraft black liquor and four different black liquors were studied: one reference black liquor (with no lignin extracted); two ligninlean black liquors with a lignin removal rate of 5.5% and 21%, respectively; and one liquor with maximum lignin removal of 60%. Evaporation tests were carried out at the research evaporator in Chalmers University of Technology. Studied parameters were liquor viscosity, boiling point rise, heat transfer coefficient, scaling propensity, changes in liquor chemical composition, and tube incrustation. It was found that the solubility limit for incrustation changed towards lower dry solids for the lignin-lean black liquors due to an increased salt content. The scaling obtained on the tubes was easily cleaned with thin liquor at 105°C. It was also shown that the liquor viscosity decreased exponentially with increased lignin outtake and hence, the heat transfer coefficient increased with increased lignin outtake. Long term tests, operated about 6 percentage dry solids units above the solubility limit for incrustation for all liquors, showed that the heat transfer coefficient increased from 650 W/m2K for the reference liquor to 1500 W/m2K for the liquor with highest lignin separation degree, 60%.

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