1. Pixel cooling specifications
Kurt Gabathuler
June 13, 2004
Pixel cooling specifications

2. For good pressure regime: inlet via top, outlet via bottom
Pixel Coolant Paths
For good pressure regime: inlet via top, outlet via bottom
+ z
- z
Pixel
Cooling
Rack
Pixel
Cooling
Rack
Left half barrel + z  - z: 124 m 5 circuits
Right half barrel - z  + z: 114 m 5 circuits
Disks at + z: 109 m circuits
Disks at - z: 127 m circuits
Total circuits

3. Pixel cooling rack

4. left
half
barrel
right
half
barrel
disks +z
disks -z
Heat
exchanger
filters
tank
Circulation pump

5. CMS Pixel Detectors and service structures inside the tracker-z
3 half-disks attached to service structure
flexible connections
barrel service
half-cylinder
half-barrel
optohybrids &
control electronics +z

6. Pixel Half Barrel 3 layers group of 4 tubes trapezoidal Al tube
with dhydr=3mm
0.3mm wall thickness

7. Cooling channels
Optohybrids

8. Frontview of half-barrel
Gap between barrel & service tube

9. One of 10 Pixel Barrel Cooling circuits
+/- z
-/+ z
32 cc/s T
T+2.0
32 cc/s
63 cc/s
63 cc/s
56.4 cc/s
service tube
service tube
47.75 cc/s
31 cc/s T
T+1.6
31 cc/s

10. Cooling of quarter disk, Forward Pixel
Alu 2.5mm x 6 mm, dhydr=3.5mm IN
OUT

12. One of 8 forward Pixel Cooling Circuit
Supply 10mm id
Service Tube 4mm id
¼ disks 6 blades
disk 1
disk 2
disk 3
15cc/s
T=1.80
45cc/s
15cc/s
15cc/s
Total pressure drop ~ 2000 mbar

13. Summary Pixel Cooling Circuits
(full pixel configuration 3 barrel layers and 23 disks)
Number of circuits
Length per circuit [m]
Flow per circuit [cc/s]
Load per circuit [W]
Coolant T [0K]
pressure drop [bar]
Barrel +z-z 5
124 63
560
5.1
2.0
Barrel -z+z
114
540
4.9
Disks +z 4
109 45
345
4.3
Disks -z
127
365
4.4
Total 18
990
8340

14. Additional slides

15. pressure transducer p  3.5 bar abs.
Bypass
pressure transducer
p  3.5 bar abs.
heat
exchanger T T
gas inlet
to blow
coolant into
reservoir
Reservoir
pump: p  1.7 bar
@ 1 liter / s X
Disks +z
Total flow 60, 120 or 180 cc/s
(1, 2, or 3 disks) X X X X P F PT X X X
P,T X X X
Disks -z
Total flow 60, 120 or 180 cc/s
(1, 2, or 3 disks) X X X X P F PT X X X
P,T X X
manual
pressure
adjustment
flowmeters
or p(in/out)
manual
valves X
Barrel +z-z
Total flow 160 or 320 cc/s
(layers 1+2 or 3 layers) X X X P X X X X F PT
P,T X X X X X X
Barrel -z+z
Total flow 160 or 320 cc/s
(layers 1+2 or 3 layers) X X P X X X X F PT
P,T X X X X

22. Barrel+z in high, -z out low
pressures in abs bar, dyn, static
0.69
0.92
path length 92.5 m 12
1. 21
1.55
1.36
2.22 10
1.02
2. 22 12
1.71
2.22
5.2 10
1.52
2.88
3.20
1.50
3.20 12
p1.70, 0
external pressure
pabs 3.20, 3.20

23. Barrel-z in high, +z out low
pressures in abs bar, dyn, static
1.30
1.55
1.25
1.55 12
path length 80.5 m
1.40
2.22 10
1.06
2. 22 12
1.75
2.22
5.2 10
1.56
2.88
3.20
1.61
3.20 12
p1.59, 0
external pressure
pabs 3.20, 3.20

24. Disks+z in high, +z out low
pressures in abs bar, dyn, static
1.11
1.22
path length 84.3 m 12
1.69
1.85
1.62
2.52 10
0.97
2. 52 12
2.28
2.52
5.2 10
1.56
3.18
3.50
1.76
3.50 12
p1.74, 0
external pressure
pabs 3.20, 3.20

25. Disks-z in high, -z out low
pressures in abs bar, dyn, static
1.73
1.85
1.71
1.85 12
path length 87.5 m
1.64
2.52 10
0.99
2. 52 12
2.30
2.52
5.2 10
1.58
3.18
3.50
1.74
3.50 12
p1.76, 0
external pressure
pabs 3.20, 3.20

26. Measurement of flow through the individual cooling pipes of pixel barrel

27. Coolant Flow Distribution (C6F14 at room temperature)2 3 4 5
35 cc/s
(measured)
35 cc/s
(measured) 1 2 3 4 5
 12 % variation
 9 % variation

28. re drops for staged pixel
Pressu
re drops for staged pixel
layer 1 or 2
Pixel detector
configuration
Number of
circuits
in operation
Nominal flow per
circuit
[cc/sec]
Total pressure
Drop
[bar]
Pressure drop
in supply/return
line [bar]
in detector
Barrel layers 1+2 10
31/32
1.00 2
0.15
0.70
Barrel layers 1+
2+3 63
1.70
0.50
BARREL
COOLING
CIRCUIT
layer 3
DISK
¼ disks
COOLING
disk 1
disk 2
disk 3
6 blades
CIRCUIT 2
1 Disk 8 15
1.35
0.05
1.25
2 Disks 30
1.55
0.15
3 Disks 45
1.75
0.25

29. Summary Pixel Cooling Circuits Flow per circuit [cc/s]
(possible initial pixel configuration barrel layers and 2  2 disks)
Number of circuits
Length per circuit [m]
Flow per circuit [cc/s]
Load per circuit [W]
Coolant T [0K]
pressure drop [bar]
Barrel +z-z 5
92.5
31.5
252
4.5
1.00
Barrel -z+z
80.5
0.89
Disks +z 4
84.3 30
204
3.8
1.54
Disks -z
87.5
1.56
Total 18
555
4152