en cooling and ventilation activity report on na62-gtk project
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EN Cooling and Ventilation Activity report on NA62-GTK project. Michele Battistin, Enrico Da Riva, Vinod Rao, P. Valente CERN Engineering Department Cooling and Ventilation Group NA62-GTK Meeting, Mainz, 6 th September 2011. Agenda. CFD simulation on Microchannel solution for GTK - PowerPoint PPT PresentationTRANSCRIPT
European Organization for Nuclear Research - Organisation européenne pour la recherche nucléaire
1GTK meeting Mainz 6th September 2011
EN Cooling and VentilationActivity report on NA62-GTK project
Michele Battistin, Enrico Da Riva, Vinod Rao, P. ValenteCERN Engineering DepartmentCooling and Ventilation Group
NA62-GTK Meeting, Mainz, 6th September 2011
M. Battistin, E. Da Riva, V. Rao, P. Valente
European Organization for Nuclear Research - Organisation européenne pour la recherche nucléaire
2GTK meeting Mainz 6th September 2011
Agenda
• CFD simulation on Microchannel solution for GTK
• Cooling unit engineering specification
M. Battistin, E. Da Riva, V. Rao, P. Valente
European Organization for Nuclear Research - Organisation européenne pour la recherche nucléaire
3GTK meeting Mainz 6th September 2011
GTK Microchannel Cooling- CFD Analysis for Hydraulic Design -
M. Battistin, E. Da Riva, V. Rao, P. Valente
European Organization for Nuclear Research - Organisation européenne pour la recherche nucléaire
Summary
4GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
European Organization for Nuclear Research - Organisation européenne pour la recherche nucléaire
Summary
5GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
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Present prototype (Design-0)
6GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Design-0 geometry
• Refrigerant C6F14, temperature = -25°C• Max inlet/outlet temperature rise = 5 K• Heat load = 48 W• cp = 975 J kg-1 K-1
Mass flow rate 9.8 g/s
A first prototype has been manufactured and tested by CERN PH/DT
The dominating thermal constraint is considered the in/out refrigerant temperature rise and not the HTC achieved inside the microchannels
Design operating conditions
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Present prototype (Design-0)
7GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Velocity in manifolds and microchannels
Design power
Mass Flow Rate
um
(manifold)Re
much
(channel)Re
ch
48 W 9.8 g/s 11.45 m/s 6882 1.81m/s 223
The flow is laminar in the microchannels and turbulent in the manifold Too high manifold velocity high pressure drop + maldistribution
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Summary
8GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
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Analytical model
9GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Most of the pressure drop is due to the manifold
0.00 2.00 4.00 6.00 8.00 10.00 12.000
2
4
6
8
10
12
14
Pressure drop variation with mass flow rate @ -25°C for present Prototype (Design-0)
manifold Pressure dropchannel Pressure droptotal pressure drop
mass flow(g/sec)
pres
sure
dro
p(ba
rs)
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Summary
10GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
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CFD model and validation
11GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Mesh data ->No. of cells : 8.2 M Hexahedra: 8.1 M polyhedra: 0.1M
->Mesh non-orthogonality Max: 39.9 Average: 3.6
The CFD model is able to predict experimental the data for the whole range of mass flow rates tested
0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.0080
1
2
3
4
5
6
Pressure drop comparison @ 15°C for Design-0
Exp.CFD
mass flow rate [kg/s]
pres
sure
dro
p [b
ar]
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Summary
12GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
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Performance of Design-0
13GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Pressure drop
Flow distribution
The refrigerant pressure drop predicted by the CFD model at design working conditions is 12.2 bar
This value could give rise to mechanical resistance problems
The Average mass flow rate in each channel is 0.03 g/sec
The distribution is not optimal The channels close to outlet are fed
with almost double the mass flow rate as compared to the ones close to the inlet
The temperature rise for the channels close to the inlet is expected to be higher then 5 K
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Summary
14GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
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15GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
As a first step to reduce the pressure drop in the manifold without changing the Design-0 main geometry , A dual inlet/outlet solution is proposed
Design-0 sketch Design-1 sketch
Flow distribution & Pressure drop
Geometry
Δp = 12.2 bar Δp = 5.7 bar
Design-1 (double inlet/outlet)
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Summary
16GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger
Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
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Influence of channel geometry
17GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
The double inlet/outlet configuration is considered.The width of the silicon wall between the channels is considered fixed
(100 μm). The mechanical resistance of high aspect-ratio channel has to be
checked. According to the present results, the material budget can be reduced
without increasing the global pressure drop.
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18GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Pressure Drop with Perfluorohexane with dual Inlet-Outlet@-25°C with 9.84g/s for 48 Watts | 100 microns wall
Channel width
No . Of channel
Channel depth ->
[Microns]50 60 70 80 90 100
500.0 50 8.3 5.6 4.3 3.5 3.0 2.7
400.0 60 8.7 5.9 4.4 3.6 3.1 2.8
328.6 70 9.1 6.2 4.6 3.8 3.2 2.9
275.0 80 9.6 6.5 4.8 3.9 3.3 3.0
233.3 90 10.2 6.8 5.1 4.1 3.5 3.1
200.0 100 10.8 7.3 5.4 4.3 3.7 3.2
172.7 110 11.6 7.8 5.8 4.6 3.9 3.4
150.0 120 12.5 8.4 6.2 4.9 4.2 3.6
130.8 130 13.6 9.1 6.7 5.4 4.5 3.9
114.3 140 14.9 10.0 7.4 5.9 5.0 4.3
100.0 150 16.6 11.2 8.3 6.6 5.6 4.8
9.7
21.1
3.0
5.7
6.1
CFD Results in Red
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Summary
19GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
A) Silicon Microchannel C6F14 Heat Exchanger
Present prototype (Design-0) Analytical model for pressure drop CFD model and validation against experimental data Performance of present prototype (Design-0) Performance of double inlet/outlet (Design-1)
B) General Design Guidelines Influence of channel geometry Possible alternative refrigerants
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Possible alternative refrigerants
20GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
For HTC calculation, Nusselt number is taken as constant (=3.2). C6F14 is the only dielectric fluid considered in the table. High cp allows to reduce mass flow rate and pressure drop. Water displays optimal properties but can be used only above 0°C. Liquid CO2 displays good properties but the saturation pressure is extremely
high even at low temperature. Ammonia displays optimal thermodynamic properties and also a very low
saturation temperature .
Fluid Temperature [°C] Pressure [bar] CP [J/Kg-k] η [cSt] Density[Kg/m3]
HTC [Laminar flow with Dh=.1mm]
C6F14 -25 1 975 .81 1805.25 2008
Water 25 1 4181 .892 997 19424
Glycol[45%] -25 1 3211 24 1080.6
CO2 -25 18 2111 .143 1054.7 4480
Ammonia -45 .9 4387.1 .43 696.18 22560
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Pressure Drop with dual Inlet-Outlet@25°C with 2.3g/s for 48 Watts | 100 microns wall
21GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Fluid : Water
Properties @ 25°C , 1 bar:
Cp = 4181 J/kg-K
kinematic viscosity (η) = 0.892 cSt
Density = 997 kg/m3
Water could be an optimal solution for operating conditions above 0°C
A cooling system operating below atmospheric pressure could be designed in order to avoid leakages problems.
Channel width
No. of channel
Channel depth ->
[microns]50 60 70 80 90 100
500.0 50 1.38 0.90 0.65 0.51 0.42 0.36
400.0 60 1.49 0.97 0.70 0.55 0.45 0.38
328.6 70 1.61 1.05 0.76 0.59 0.48 0.41
275.0 80 1.76 1.15 0.83 0.64 0.52 0.44
233.3 90 1.92 1.26 0.91 0.70 0.57 0.48
200.0 100 2.12 1.39 1.01 0.78 0.63 0.53
172.7 110 2.35 1.55 1.12 0.86 0.70 0.59
150.0 120 2.63 1.74 1.26 0.97 0.79 0.66
130.8 130 2.97 1.98 1.43 1.11 0.90 0.75
114.3 140 3.38 2.27 1.65 1.28 1.03 0.86
100.0 150 3.90 2.63 1.92 1.49 1.21 1.01
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Pressure Drop with dual Inlet-Outlet@-25°C with 3g/s for 48 Watts | 100 microns wall
22GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Fluid : Glycol 45% solution
Properties @ -25°C :
Cp = 3211 J/kg-K
kinematic viscosity (η) = 24 cSt
Density =1080.6 kg/m3
Freezing Point = -30.5°C
Glycol cannot be used to employ water in microchannels below 0°C, because the viscosity is extremely high.
Channel width
No. of channel
Channel depth ->
[microns]50 60 70 80 90 100
500.0 50 42.59 25.55 16.67 11.56 8.40 6.34
400.0 60 46.40 28.06 18.45 12.89 9.43 7.16
328.6 70 50.78 30.96 20.51 14.44 10.65 8.14
275.0 80 55.86 34.35 22.94 16.27 12.08 9.30
233.3 90 61.78 38.32 25.81 18.45 13.80 10.69
200.0 100 68.74 43.03 29.22 21.05 15.86 12.37
172.7 110 77.00 48.65 33.33 24.20 18.37 14.43
150.0 120 86.90 55.45 38.32 28.06 21.46 16.97
130.8 130 98.90 63.74 44.46 32.83 25.29 20.15
114.3 140 113.64 74.01 52.11 38.80 30.13 24.17
100.0 150 131.98 86.90 61.78 46.40 36.31 29.33
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Pressure Drop with dual Inlet-Outlet@-25°C and 18 bars with 4.5g/s for 48 Watts | 100 microns
wall
23GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Fluid : Carbon Dioxide
Properties @ -25°C, 18 bar
Cp =2111 J/kg-K
kinematic viscosity (η) = 0.143 cSt
Density =1054.7 kg/m3
The pressure drop with liquid CO2 is extremely low, but this is useless since the saturation pressure of CO2 is high (16.8 bar @ -25°C).
Channel width
No. of channel
Channel depth ->
[microns]50 60 70 80 90 100
500.0 50 1.05 0.90 0.82 0.77 0.74 0.73
400.0 60 1.08 0.92 0.83 0.79 0.75 0.73
328.6 70 1.12 0.95 0.85 0.80 0.77 0.74
275.0 80 1.17 0.98 0.87 0.82 0.78 0.75
233.3 90 1.22 1.01 0.90 0.83 0.79 0.77
200.0 100 1.28 1.05 0.93 0.86 0.81 0.78
172.7 110 1.36 1.10 0.97 0.89 0.83 0.80
150.0 120 1.45 1.16 1.01 0.92 0.86 0.82
130.8 130 1.55 1.24 1.07 0.96 0.90 0.85
114.3 140 1.68 1.33 1.14 1.02 0.94 0.89
100.0 150 1.85 1.45 1.22 1.08 0.99 0.93
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Pressure Drop with dual Inlet-Outlet@-45°C with 2.19g/s for 48 Watts | 100 microns wall
24GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
Fluid: Ammonia
Properties @ -45°C, 0.9 bar
Cp =4387.1 J/kg-K
kinematic viscosity (η) = 0.43 cSt
Density = 696.18 kg/m3
Ammonia could be an optimal solution for operating conditions below 0°C
A cooling system operating below -35°C and below atmospheric pressure could be designed in order to avoid leakages problems.
Channel width
No. of channel
Channel depth ->
[microns]50 60 70 80 90 100
500.0 50 0.80 0.57 0.46 0.39 0.35 0.32
400.0 60 0.85 0.61 0.48 0.41 0.36 0.33
328.6 70 0.91 0.65 0.51 0.43 0.38 0.35
275.0 80 0.97 0.69 0.54 0.45 0.40 0.36
233.3 90 1.05 0.74 0.58 0.48 0.42 0.38
200.0 100 1.14 0.80 0.62 0.52 0.45 0.40
172.7 110 1.25 0.88 0.68 0.56 0.48 0.43
150.0 120 1.38 0.97 0.74 0.61 0.52 0.46
130.8 130 1.54 1.08 0.82 0.67 0.57 0.50
114.3 140 1.73 1.21 0.92 0.75 0.63 0.56
100.0 150 1.97 1.38 1.05 0.85 0.72 0.62
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Conclusions
25GTK meeting Mainz 6th September 2011 M. Battistin, E. Da Riva, V. Rao, P. Valente
The velocity in the manifold of the present prototype is too high, therefore the total pressure drop is high (i.e. ~12 bar) and the flow distribution is not uniform.
Before improving the channels design, the manifold design must be fixed.
Adopting double inlets/outlets allow to half the pressured drop and improve the flow distribution without changing the overall manifold geometry.
Neglecting possible mechanical resistance problems, the material budget could be further decreased by adopting high aspect ratio channels.
From the hydraulic point of view, liquid ammonia at around -40°C would allow to operate a microchannel heat exchanger below the atmospheric pressure thus avoiding mechanical resistance and leakages problems.
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NA62 Gigatracker cooling systemengineering specification
Piero Valente, Michele Battistin
26
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Thermodynamic requirements – Fluid: C6F14
– Total required cooling power : 300 W (spare power factor =2)– Number of distribution loops = 3– Supply temperature = -25C– Loop temperature stability = ± 0.5K– Temperature difference between loops = 2 K– Design pressure: 16 bar– Pressure drop : still to be defined by GTK collaboration
27
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User requirements – VDF pump power supply for smooth start-up sequence– PVSS-UNICOSS control and supervision– Control cupboards installed in the remote protected area (200 m
distance)– Automatic control of loop flowrate and temperature– Remote control of delivery temperature and flow rate for each loop– Interlocks for high delivery pressure– Fully redundant operation: chiller, heat exchanger and circulation pump– Oil free cooling station– Pneumatically actuated valves– Cooling station to be tested in laboratory - Meyrin site
28
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Proposed solution– HCFC refrigerant primary chiller (-40 °C)
– Chiller overall cooling power: 1.5 kW (including heat losses)
– C6F14 total mass flow ≈ 0.333 kg/s (pre-design figure)
– Three bigger pipelines (OD 12) carrying ≈ 0.100 kg/s C6F14 flow each
– Three smaller pipelines (OD6) carrying 0.011 kg/s C6F14 flow to each detector
– A heat exchanger for each line, located ≈1 meter from the detector, will guarantee operating temperature setting of -25C
29
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Proposed solution : P&I
30
Main pipelines OD 12
Detector pipelines OD 6
Heat exchangers
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31
Planning– Engineering specification approval …….. end September 2011 (EN-CV; NA62)
– System design ……………………………………. October-November 2011 (EN-CV)
– Procurement ……………………………………… December 2011-March 2012 (EN-CV;FP)
– Installation ………………………………………… April-June 2012(EN-CV; Contractor)
– Tests…………………………………………………… July-September 2012(EN-CV;Contractor)
– Commissioning…………………………………… October 2012 (EN-CV; Contractor)
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32
Budget
– Mechanical components………………………..110 kCHF
– Electrical and control equipments ….……..30 kCHF
– Manpower………………………………….….……..40 kCHF
Total 180 kCHF
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Alternative solutions?CERN TOTEM Cooling system
Michele Battistin
33
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TOTEM Roman Pots C3F8 Evaporative cooling system
Eng Spec EDMS 778214 v1
POTS STATIONS LOCATION
DESIGN PARAMETERS
XRP1 XRP3XRP3
XRP1
Main station
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Roman Pot cooling
Evaporative system @ C3F8Lamination phase between points A and B
A
B
C
OPTION 1 - Capillary
lamination into a capillary located insidethe Pot
+ no need of insulation and heatintake on the supply line, horizontalflexibility
- to be individually tested, timeconsuming, behaviour off design to bestudied
OPTION 2 - Manual valve
lamination into a manually adjustablevalve located outside the Pots, as near aspossible
+ commercial component, time andcost effective, reliability, flexibility
- need of insulation to avoidcondensation, heat intake fromenvironment
A BC
Compressor design[ data from HAUG, supplier of dry compressors succesfully
tested for SR1 and Atlas evaporative machine]
Nominal flow rate 2 g/s per circuit48 g/s total20.3 Nm3/h
Option 1
WTEGX 80/603 cylinders2 stages
0.8-10 bara @ 13 Nm3/h1.0-10 bara @ 18 Nm3/h
~30 kCHF
Option 2
VTOGX 120/602 cylinders2 stages
0.8-10 bara @ 20 Nm3/h1.0-10 bara @ 30 Nm3/h
~50 kCHF
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TOTEM RP cooling
C3F8 main working points
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TOTEM RP cooling
System schematicPI
01
PT
01
PI
02
PT
02
PI
03
PT
03
PI
04
PT
04
PI
12
PT
09
XRP1 - UJ57
XRP3 - UJ57
XRP1 - UJ53
XRP3 - UJ53
NC NC
NC NC
TT
01
Mixed waternetwork
C3F8 Storagetank
TT
14
PI
11
PT
07
Capillary 01
Capillary 02
RP coil 01
RP coil 02
Capillary 03
Capillary 04
RP coil 03
RP coil 04
Capillary 05
Capillary 06
RP coil 05
RP coil 06
Internal of the Roman Pots
Limit of TS/CV/DC supply
Demineralisedwater network
DN50
DN10
DN10DN50
PT
08
DN32
DN32
DN25
TT
13
FT
01
TT
10
TT
02
TT
03
TT
04
PT
05PI
07
PI
06
PI
05
TT
07
TT
06
TT
09
PT
06PI
10
PI
09
PI
08
WCS
01 TT
15
DN25
FT
02
TT
12
TT
11
A
BC
D
F
DUMMYLOAD
PI
13
TT
16
Back pressureregulators
60 mbar @ 10 g/s
Pressure regulators100 mbar @ 10 g/sPT
10
PT
11
PT
12
PT
13
NO
NO
NO
NO
NC
NC
NC
NC
TT
05
TT
08
PID reg
PID reg
PID reg
G
E
DonaldsonUltrafilters
Flexibleconnection
DN25
DN25
DN25
DN15
DN15
NC
DN15
DN10
Copper return
liquid line 26/28
Copper supply
gas line 12/14
DN10
G
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Could it be the solution for GTK?
• The solution has already been used for TOTEM electronics (25 W; 2 g/s; C3F8)
• Low operation temperature easily achivable (-43°C during Totem tests)
• Low opeartion pressure on the detector (1 bara; -37°C)
• The system is running since 2007 with high reliability
• Tranfer lines operates at ambient temperature: can be very long (300 m for Totem): the cooling station ca be in an accessible area (no operation in the protected zone)
• Temperature stability and uniformity is granted by the evaporation temperature
• Known thecnology both on detector structure than on the cooling system.