Methods of Increasing Thermal Conductivity of Plasma Sprayed Tungsten-Based Coatings

2008 ◽  
Vol 59 ◽  
pp. 82-86 ◽  
Author(s):  
Jiří Matějíček ◽  
Karol Iždinský ◽  
Petr Vondrouš
Keyword(s):  
Thermal Conductivity ◽  
Thermal Characterization ◽  
High Heat ◽  
Molten Copper ◽  
Point Of View ◽  
The Other ◽  
High Heat Flux ◽  
Plasma Facing Components ◽  
Graded Layers ◽  
Plasma Sprayed

Tungsten is the main candidate material for the armor of plasma facing components for ITER and future fusion devices [1]. Plasma spraying is an alternative method for manufacturing tungsten-based coatings, including composites and graded layers, having a number of advantageous features [2]. On the other hand, the main limitation to application of these coatings on high heat flux components, is their low thermal conductivity, originating in the layered structure [3]. This paper is focused on four methods of improving the coatings’ thermal conductivity. First method consists in modification of the basic spraying parameters, which have a direct influence on the coating structure and therefore properties. The other three methods involve post-processing of the coatings: molten copper infiltration, laser remelting and densification by HIPping. The latter encompasses also tungsten-copper composites of various compositions. Experimental results, including structural and thermal characterization, are presented for each method. Finally, the applicability of these methods, from the point of view of manufacturing the plasma facing components, is discussed.

High Heat Flux Testing of TiC-Doped Isotropic Graphite for Plasma Facing Components

2008 ◽  
Vol 59 ◽  
pp. 288-292 ◽  
Author(s):  
I. López-Galilea ◽  
G. Pintsuk ◽  
C. García-Rosales ◽  
Jochen Linke
Keyword(s):  
Energetic Electron ◽  
High Heat ◽  
Point Of View ◽  
Raw Material ◽  
Design Solution ◽  
High Heat Flux ◽  
Excessive Heat ◽  
Plasma Facing Components ◽  
Material Solution ◽  
Transient Thermal

The technical design solution for the future thermonuclear fusion reactor, ITER, must guarantee a reasonable lifetime from a safety and economical point of view. Carbon fibre reinforced carbon (CFC) is envisaged as a corrective material solution for the strike point area of ITER divertor due to its high thermal shock resistance necessary to withstand excessive heat loads during transient thermal loads; in particular plasma disruptions that can deposit energy densities of several ten MJm-2 with a typical timescale in the order of milliseconds. In this work, as potential alternative to CFCs new finely dispersed TiC-doped isotropic graphites with high thermal conductivity and mechanical strength, manufactured using synthetic mesophase pitch “AR” as raw material, have been evaluated under typical disruption conditions using an energetic electron beam at the JUDITH facility.

scholarly journals Design and Analysis of High Heat Flux Plasma-Facing Components for NSTX Upgrade

2021 ◽  
pp. 1-7
Author(s):  
Andrei Khodak ◽  
Douglas Loesser ◽  
Michael Messineo ◽  
Arthur Brooks ◽  
Michael Jaworski ◽  
...  
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
High Heat Flux ◽  
Plasma Facing Components

Thermal response of plasma sprayed tungsten coating to high heat flux

2004 ◽  
Vol 70 (4) ◽  
pp. 341-349 ◽  
Author(s):  
X. Liu ◽  
L. Yang ◽  
S. Tamura ◽  
K. Tokunaga ◽  
N. Yoshida ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Response ◽  
High Heat ◽  
High Heat Flux ◽  
Tungsten Coating ◽  
Plasma Sprayed

Plasma-Sprayed Beryllium on Macro-Roughened Substrates for Fusion Reactor High Heat Flux Applications

2007 ◽  
Vol 16 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Kendall J. Hollis ◽  
Brian D. Bartram ◽  
Manfred Roedig ◽  
Dennis Youchison ◽  
Richard Nygren
Keyword(s):  
Heat Flux ◽  
Fusion Reactor ◽  
High Heat ◽  
High Heat Flux ◽  
Plasma Sprayed

Fabrication and high heat flux testing of plasma sprayed beryllium ITER first wall mock-ups

1998 ◽  
Vol 258-263 ◽  
pp. 252-257 ◽  
Author(s):  
R.G Castro ◽  
K.E Elliot ◽  
R.D Watson ◽  
D.L Youchison ◽  
K.T Slattery
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
High Heat Flux ◽  
First Wall ◽  
Plasma Sprayed

Vapor shield protection of plasma facing components under incident high heat flux

1992 ◽  
Vol 196-198 ◽  
pp. 596-601 ◽  
Author(s):  
J. Gilligan ◽  
M. Bourham ◽  
O. Hankins ◽  
W. Eddy ◽  
J. Hurley ◽  
...  
Keyword(s):  
Heat Flux ◽  
High Heat ◽  
High Heat Flux ◽  
Plasma Facing Components

scholarly journals R&D on divertor plasma facing components at the Institute for Plasma Research

Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 285-288 ◽  
Author(s):  
Yashashri Patil ◽  
S. Khirwadkar ◽  
S. M. Belsare ◽  
Rajamannar Swamy ◽  
M. S. Khan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Temperature ◽  
Infrared Thermography ◽  
High Heat ◽  
High Heat Flux ◽  
Acceptance Criteria ◽  
Plasma Facing Components ◽  
Type Test ◽  
Plasma Research

Abstract This paper is focused on various aspects of the development and testing of water cooled divertor PFCs. Divertor PFCs are mainly designed to absorb the heat and particle fluxes outflowing from the core plasma of fusion devices like ITER. The Divertor and First Wall Technology Development Division at the Institute for Plasma Research (IPR), India, is extensively working on development and testing of divertor plasma facing components (PFCs). Tungsten and graphite macro-brush type test mock-ups were produced using vacuum brazing furnace technique and tungsten monoblock type of test mock-ups were obtained by hot radial pressing (HRP) technique. Heat transfer performance of the developed test mock-ups was tested using high heat flux tests with different heat load conditions as well as the surface temperature monitoring using transient infrared thermography technique. Recently we have established the High Heat Flux Test Facility (HHFTF) at IPR with an electron gun EH300V (M/s Von Ardenne Anlagentechnik GmbH, Germany) having maximum power 200 kW. Two tungsten monoblock type test mock-ups were probed using HHFTF. Both of the test mock-ups successfully sustained 316 thermal cycles during high heat flux (HHF) tests. The test mock-ups were non-destructively tested using infrared thermography before and after the HHF tests. In this note we describe the detailed procedure used for testing macro-brush and monoblock type test mock-ups using in-house transient infrared thermography set-up. An acceptance criteria limit was defined for small scale macro-brush type of mock-ups using DTrefmax value and the surface temperature measured during the HHF tests. It is concluded that the heat transfer behavior of a plasma facing component was checked by the HHF tests followed by transient IR thermography. The acceptance criteria DTrefmax limit for a graphite macro-brush mock-up was found to be ~3°C while for a tungsten macro-brush mock-up it was ~5°C.

scholarly journals Natural Materials for Thermal Insulation: Mulch and Lava-Rock Characterizations

2014 ◽  
Vol 705 ◽  
pp. 8-13
Author(s):  
Aurélien P. Jean ◽  
Craig Adams ◽  
Mario A. Medina ◽  
Frédéric Miranville
Keyword(s):  
Thermal Conductivity ◽  
Statistical Data ◽  
Thermal Characterization ◽  
Temperature Sensors ◽  
The Other ◽  
Natural Materials ◽  
Data Manipulation ◽  
Heating Source ◽  
Building Insulation ◽  
Wall System

This paper reports on the thermal characterization, via the thermal conductivity, of natural materials, such as mulch and lava rock and their usefulness as building insulation. Experiments were carried out using a scale one monitored wall (i.e. heat flux and temperature sensors) exposed to a heating source on one side and to an air conditioned space on the other. The wall system was composed of an 8.85 cm thick cavity, where the mulch and lava rock were placed. The cavity was enclosed between two layers of pine wood (40 mm thick each). After the experiments and statistical data manipulation, the estimated thermal conductivity of the materials were 0.48 ± 0.001 W.m-1.K-1 and 0.129 ± 0.003 W.m-1.K-1 for mulch and lava-rock, respectively. That is, mulch has a thermal conductivity comparable to that of bulk hemp while lava rock has a thermal conductivity comparable to that of hemp brick. These values indicate the usefulness of mulch, compared to the impracticality of using lava-rocks materials for building insulation.

Thermal Conductivity and Operating Temperature Effect on the Interline Region in a Micro/Miniature Heat Pipe

2008 ◽  
Author(s):  
Hani H. Sait ◽  
Steve M. Demsky ◽  
HongBin Ma
Keyword(s):  
Thin Film ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Operating Temperature ◽  
High Heat ◽  
Working Fluid ◽  
High Heat Flux ◽  
Thin Film Evaporation ◽  
Film Evaporation ◽  
Frictional Shear Stress

An analytical model describing thin film evaporation is developed that includes the effects of surface tension, frictional shear stress, wetting characteristics and disjoining pressure. The effects of thermal conductivity of working fluids and operating temperature on the evaporating thin film region are also studied. The results indicate that when the thermal conductivity of the working fluid increases, a high heat flux can be removed from the evaporating thin film region. The operating temperature affects the thin film evaporation. The higher the operating temperature, the more heat flux can be removed from the region. The information of thin film evaporation presented in the paper results in a better understanding of heat transfer mechanism occurring in micro heat pipes.

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