Download heat transfer properties

ASIPP
HT-7 & EAST
High heat load properties of actively cooled
tungsten/copper mock-ups joining by
explosive compound
Presented by H. Li1
J.L. Chen1, J.G. Li1, Z.X. Li2
lhua@ipp.ac.cn
1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, P.R.China
2. Northwest Institute for Non-ferrous Metal Research, Xi’ an 710016, P.R.China
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
HT-7 & EAST
Outline
• Motivation
• Mock-ups and experiments
---- Mock-ups, Tungsten(2mm) as PFM , CuCr alloy as heat sink , explosive compound
---- Electron high heat flux experiments
high heat load limit test; heat transfer properties
---- Numerical Simulation
---- Microstructure analysis
• Results and discussion
• Conclusions
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
HT-7 & EAST
Motivations
Tungsten, candidate of PFM
High melting point, Low erosion, low tritium retention etc.,
Copper alloy, heat sink material
High conductivity, high strength at elevated temp.(CuCrZr)
Disadvantages in joining technique
Large differences in CTEs and elastic modulus resulting in high stress.
Structure reliability and lifetime in cycling operation.
W/CuCr mock-ups joining by explosive compound
Developed and manufactured for EAST in ASIPP.
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
HT-7 & EAST
ASIPP
Mock-ups
W plate with 2mm thickness
by forging
A, 30*60mm
H.Li
B, 30*30mm
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
HT-7 & EAST
2mm
3mm
Cooling conditions
6mm
10mm
Pressure 0.3MPa
Temperature 300C
Flow rate 3m3/s
Heat load conditions
Heat flux 1~10MW/m2
Cross-sectional view of the mock-up
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
HT-7 & EAST
Electron beam facility
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
HT-7 & EAST
Heat load limit test
Mock-up A
• Joint temp. reached
about 4700C and then
rising rapidly.
• One side of the mock-up
appeared continuous hot
spots and red.
• delamination happened.
• The heat load limit is
7MW/m2.
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
Microstructure analysis
HT-7 & EAST
W
Delamination
Cu
Cracks originated at the edge and then expanded to center, which resulted in
delamination.
A larger mumber of cracks appeared at the other side of the copper/filler jointface after tests.
At high temp.(4700C), high stress and large plastic strain happeded near the
copper/filler material joint-face.
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
Heat load properties
HT-7 & EAST
Mock-up B
•Under 2, 4MW/m2, good
agreement in temp. between
tests and simulation, which
indicated
good thermal contact and
high heat trasfer capability at
the joint.
•Under 6MW/m2,
joint temp. higher than simulation and slightly rising in the end of the heat
loading, which meant the thermal contact was not good as that under 4MW/m2.
The cooling time, slightly longer under 6MW/m2 than under other heat flux.
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
HT-7 & EAST
ASIPP
Microstructure analysis
Before tests
After tests
Tungsten/filler joint-face is good before and after heat load.
Before tests(after joining), pores appeared in the filler material.
After heat loads, the cracks appeared near the filler/Cu joint face and reduced
the heat transfer capability, which resulted in higher joint temp.
For W/Cu joints, the cracks or faluires often happened near the copper.
Avoiding the strength reduction of the copper and improving the filler material’s
properties (CTEs, modulus, ductibility, adhesion, etc.) is the key issue.
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
6MW/m2
HT-7 & EAST
Simulation
h=6mm
• High temp. of the joint-face under Heat flux of 6MW/m2 is dangerious
for W/Cu joint.
• if reducing the distance between the vertex and jointface to 3mm, the
temp. of the joint-face (center) decreased from 3600C to 3000C under
6MW/m2 and the mock-up would have more structure reliability.
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
HT-7 & EAST
Conclusion
Two mock-ups with forging W plate and CuCr heat sink joining by explosive
compund were developed, manufactured and tested.
 The heat load limit of the mock-up is 7MW/m2, and delamination happened.
But the mock-up can sustain about 6MW/m2 although some cracks happened at
the joint face.
If the heat load does not exceed 4MW/m2, the mock-up will have good heat
transfer properties and good structure stability.
If reducing the distance between the vertex of the channel and the joint-face
from 6mm to 3mm, it is expected that the mock-up has higher reliability due to
lower temp. at the joint-face.
The cracks or failures often originated and developed at copper/filler jointface,especially near the edge. For W/CuCr explosive compund, the properties
of filler materials and the adhesion strength are very important to its reliability
and lifetime under high heat loading.
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
HT-7 & EAST
Thanks
H.Li
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
H.Li
HT-7 & EAST
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
H.Li
HT-7 & EAST
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
H.Li
HT-7 & EAST
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
H.Li
HT-7 & EAST
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China
ASIPP
H.Li
HT-7 & EAST
17th International Conference on Plasma Surface Interactions in Controlled Fusion Devices, 22-26 May, 2006, Hefei China