A New Panel Test Facility for Effective Thermal Conductivity Measurements up to 1,650°C

2007 ◽  
Vol 28 (5) ◽  
pp. 1668-1678 ◽  
Author(s):  
Gerald Barth ◽  
Ulrich Gross ◽  
Rhena Wulf
1998 ◽  
Vol 34 (3P2) ◽  
pp. 877-881 ◽  
Author(s):  
Mikio Enoeda ◽  
Kazuyuki Furuya ◽  
Hideyuki Takatsu ◽  
Shigeto Kikuchi ◽  
Toshihisa Hatano

1987 ◽  
Vol 109 (2) ◽  
pp. 215-221 ◽  
Author(s):  
D. W. Anderson ◽  
R. Viskanta ◽  
F. P. Incropera

The effective thermal conductivity of coal ash deposits strongly influences heat transfer in pulverized coal-fired boilers. In this study thermal conductivity measurements were performed over a wide range of temperatures for fly ash, slagging deposits, and fouling deposits. The effects of ash particle size, thermal history, and physical structure of the deposit are discussed. Thermal history and deposit structure were observed to have the greatest influence on the local thermal conductivty, which increased by an order of magnitude with particle melting. Conductivities for solid-porous deposits were twice those of the same sample in particulate form.


Author(s):  
Pengxin Cheng ◽  
Cheng Ren ◽  
Yongyong Wu ◽  
Rui Li

A full-scale heat transfer test facility has been designed and built for the determination of effective thermal conductivity of pebble bed, which is a macroscopic parameter to characterize the heat transfer capacity of the core in the High Temperature Gas-Cooled Reactor. The data acquisition system is developed to collect, display and record the temperature data in monitoring points. Two alternative software systems are designed to obtain better performance. To enhance precision of the measurement system, several aspects are analyzed and optimized in the implementation of LabVIEW. The error of the hardware system is analyzed, which is within the acceptable range. The data acquisition system can meet the practical demands of temperature acquisition in the range of thermal analysis.


2011 ◽  
Vol 45 (23) ◽  
pp. 2465-2473 ◽  
Author(s):  
Qin Zhang ◽  
Zhihua Pi ◽  
Mingxiang Chen ◽  
Xiaobing Luo ◽  
Ling Xu ◽  
...  

The effective thermal conductivity of silicone/phosphor composites is studied experimentally and numerically. Thermal conductivity measurements are conducted from 30°C to 150°C for the composites with phosphor volume fraction up to 40%. In the numerical study, a finite element model with empirical particle size distribution and random particle position is constructed using a probability density function and the Monte Carlo method, and the interfacial thermal resistance layer between phases also introduced in the model. The results indicate that when phosphor concentration is below 25 vol.%, the conductivity of the composite increases slightly with either phosphor volume fraction or temperature, and the Kapitza radius of the composite is 0.8 µm. When phosphor concentration is above 25 vol.%, the increase of conductivity correlates positively with phosphor volume fraction significantly but negatively with the temperature, and the Kapitza radius is 0.032 µm.


2014 ◽  
Vol 271 ◽  
pp. 444-458 ◽  
Author(s):  
P.G. Rousseau ◽  
C.G. du Toit ◽  
W. van Antwerpen ◽  
H.J. van Antwerpen

1997 ◽  
Vol 119 (3) ◽  
pp. 401-405 ◽  
Author(s):  
J. E. Graebner ◽  
K. Azar

The effective thermal conductivity κ of multilayer printed wiring boards (PWBs) has been measured for heat flowing in a direction either parallel (κ∥) or perpendicular (κ⊥) to the plane of the board. The conductivity of the glass/epoxy insulating material from which the boards are manufactured is anisotropic (κ∥ge ≈ 3 × κ⊥ge) and nearly three orders of magnitude smaller than the conductivity of copper. This large difference between glass/epoxy and copper produces extremely high anisotropy in PWBs that contain continuous layers of copper. For such boards, values of the board-averaged conductivity in the two directions can differ by a factor of ~100 or more. The value of κ∥ is found to depend on the ratio of the total thickness of continuous layers of copper to the total thickness of glass/epoxy, while it depends hardly at all on the amount of copper circuitry visible on the surface.


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