Transcript Folie 1 - Indico

Powering via cooling pipes
very first results
07.10.2008
Jochen Ebert, Uni Karlsruhe
1
Idea:
Combination of cooling pipes, current lead and parts of
mechanical support into one single structure.
-
~50A
+
Problem:
every hybrid see´s a different
voltage.
~1A
Solution:
combine different cross-sections of alu.
The voltage drop partially compensated
by similar voltage drop in return line.
07.10.2008
Jochen Ebert, Uni Karlsruhe
2
Module design by powering via cooling pipes
Modules mounted alternately
above and under the alu
structure
Supply and
return line for
CO2
07.10.2008
Cooling channels
Jochen Ebert, Uni Karlsruhe
3
Prototype ladder for cooling and powering
2.52 m long ladder with 56 dummy heaters
powered via cooling pipes
cooled CO2
bottle in freezer
with mounted
pressure
regulator
07.10.2008
ladder in insulation box
Jochen Ebert, Uni Karlsruhe
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Layout of ladder
56 dummy heaters
2mm pure aluminum pipe
liquid CO2 from freezer
left pipe
right pipe
2.52m
position of PT1000 sensor
2 long pipes for
environmental heating
(no liquid to flowmeters)
ladder is mounted on rohacell
to flowmeter 1 & 2 (with
adjustable valve)
07.10.2008
Jochen Ebert, Uni Karlsruhe
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detail view of heaters
• thin, flexible capton pcb´s glued on aluminum
for good heat conduction to cooling pipes
• screwed on alu blocks with nylon screws to
avoid electric contact between alu blocks and
backside of heaters
•different, pure aluminium power rails mounted
on side of blocks to get the cross-sections
needed.
•alu blocks made of two parts, screwed
together and surround the cooling pipes
07.10.2008
Jochen Ebert, Uni Karlsruhe
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cross-section and voltage
simulation
1,9345
U_heater [V]
60
50
40
30
20
10
0
1,934
Max. delta V=1,89 mV
1,9335
1,933
1,9325
1,932
0
50
100
150
200
250
300
0
5
length [cm]
Large difference between simulation
and measurement due to contact
resistances (24 powerrails screwed
to coolingblocks! -> 48 contacts).
But still quite good, and gets even
smaller with cooling (~ factor 2)
Can be avoided by fabrication out of
one piece of aluminum.
10
15
20
number of heater
25
30
25
30
voltage at heaters with I=24A @ 40°C
U_heater [V]
cross-section [mm²]
Alu cross-section vs. length of ladder
1,945
1,94
1,935
1,93
1,925
1,92
1,915
1,91
1,905
1,9
1,895
1,89
Max. delta V=43 mV
0
5
10
15
20
number of heater
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Cooling
Heat leak through insulation
@-31°C: about 90W
Dry-out at the end of the
pipe, while the beginning is
still cooled properly
electrical
heating power:
0W
17W
44W
84W
0W
CO2 flow: 2x 400liter/h = 2x 0,7kg/h
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Cooling
heavy dry-out
beginning dry-out
electrical
heating power:
44W
84W
110W
CO2-flow: 2x 800liter/h = 2x 1,5kg/h
07.10.2008
140W
187W
230W
Heat leak through insulation
@-31°C: about 90W
Jochen Ebert, Uni Karlsruhe
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dry-out
flow was tested up to 3,7
kg/hour (max. of
flowmeters) with
negligible pressure drop
Even much bigger flow
seems possible with
tolerable pressure drop
07.10.2008
beginning dry-out
total heating power [W]
easy to cool large
powers with a little flow
of CO2,
300
250
200
150
100
50
0
0
0,5
1
1,5
2
2,5
3
flow in kg/hour (both tubes)
Jochen Ebert, Uni Karlsruhe
10
regulating temperature with pressure
30
20
10
temperature [°C]
0
0
10
20
30
40
50
-10
60
time [min]
sensor1
-20
sensor2
sensor4
-30
-40
-50
-60
-70
CO2 pressure
in [bar]
11,5bar
8bar
6,5
5,5
very easy to set and hold temperature: just keep pressure constant
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Summary
•CO2 cooling with 2mm ID cooling pipes allows to cool long ladders
(tested up to 300 W, needed only 50 W / ladder)
•Putting a CO2 bottle in a 500 Euro freezer allows a very cheap
and efficient CO2 cooling system (CO2 blown into the air).
Temperature can be set anywhere between 0 and -50 C
by pressure regulator on precooled bottle.
•Test proofs that long barrel with endcap as inner discs is possible
07.10.2008
Jochen Ebert, Uni Karlsruhe
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outlook
• Measure the noise of existing modules while
powering via coolingpipes (2,5m long
„antennas“).
• What happens if one module is noisy.
• Improve contact between powerrails e.g
alondining (thin chrom coating)
• Improve precision of existing measurements.
07.10.2008
Jochen Ebert, Uni Karlsruhe
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BACKUP
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Strawman with long barrel and
discs at small radii
Stereo
Single
Trigger
Trigger
Single
Stereo
Stereo
Single
Single
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Strixel disk design
Outer radius 35 cm
2 outside rings same for
each disk
Inner ring radius changes
with z -> slightly more overlap
between sensors if same number
and same size of sensor
Each ring in two halves with
each half built as long ladder
Need 3 types of sensor
All sensors 10 cm at top
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Alternative: rectangular sensors
Can use same sensors
as in barrel, if some
more overlap allowed.
Can have SAME hybrids
and same “circular” ladder
for each ring
Will have middle ring at
back of rohacell, so enough
space for mounting
on cooling rings
Note: disks in two halves
in order to mount with
beam pipe in place
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Material/X0
Material budget with small end discs
h
07.10.2008
Jochen Ebert, Uni Karlsruhe
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Material budget
07.10.2008
Jochen Ebert, Uni Karlsruhe
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