Status overview of the cooling 31 August 2015 Bart Verlaat, Raphael Dumps 1.
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Transcript of Status overview of the cooling 31 August 2015 Bart Verlaat, Raphael Dumps 1.
Status overview of the cooling
31 August 2015
Bart Verlaat, Raphael Dumps 1
Progress points
• Many progress wrt the Velo evaporator concept and safety system is achieved.– Connector-less evaporator concept (CLEC) intensively discussed and
getting more and more accepted– Tertiary vacuum concept based on CLEC on top secondary extension is
also becoming the baseline in peoples thinking– Discussions with mechanics people (Liverpool) will continue in Velo module
0 meetings on Tuesdays.• With a frozen evaporator concept the safety system can be designed
– Test set-up under construction at CERN to study impact of a leak (Vacuum-pressure vs CO2 leaked mass)
– Test set-up will / can be used to test safety system• Sizing of regulation valves in the manifolds have started.
– A study for new control valves– Valve size calculations
2
The Connector-Less Evaporator Concept (CLEC)
3
Module with long tubes and feedthrough connector mounted on the assembly jig. Connectors and tubes are brazed to the microchannel before module assembly The cooling lines are unrolled prior to
installation. The lines are routed on the side of the module base
The feedthroughs are bended towards tertiary vacuum by an access hole in the secondary vacuum stand-off
Expected rolled up size: ca 10x10cm
Connectors can be fixed to manifold in the tertiary vacuum box
Tertiary vacuum with CO2 manifolds
All
Upgrade Velo concept vs current Velo
4
All inlet capillaries on 1 side. Return common (Manifold inside)
Electronics crates
Cable feedthrough
Tertiary vacuum with manifolds and safety valves
Cooling feed through with thermal stand-off
Out of the way space for cooling connector and flexible part
Cooling lines passing the module base on the side
Access flange
Cooling feed through
5
• 2x 1/8” VCR Gland (D=1/4”)• 1/8” VCR glands without nuts are
very small and fit both through a 14mm hole (10mm would even work when staggered)
• A split nut à la IBL can be installed after insertion
Hole diameter 10-14mm
Braze connection (Cold)
O ring or copper seal connection (Warm)
Mounting possible from both sides
Atlas-IBL cooling line
Dgland flange=1/4” (6.35mm)
VCR split nut
1/8” VCR with split nut
Split nuts assembled after insertion
Custom
Standard Conflat
Prototype
6
Tubes are firmly fixed to the base by an insulator spacer
2 spools with a diameter of 50mm, length 1.2m.(Can be roll on a better support)
Welded standard vacuum feedthroughCF15 on a stainless steel flange
Welded tubes on a vacuum feed trough(thermal insulator)
Temporaryholding support
2x module pitch
Connector can be used for testing (With connector saver), vacuum feedthrough as well
7
D=1/4” (6.35mm)
1/8” VCR with split nutmounted after tube insertion(gain of space)
Installation of the connector through the vacuum flange
Venting CO2 in vacuum
8
3.5 g/m3 => v=285 m3/kg
Far off scale
Ca 350 kJ/kg*1.6 g = 560 J to heat it up to ambient.
Condition of -30 C ⁰liquid
Condition of +20 C ⁰low pressure gas
• Module volumes and CO2 content @ -30ºC liquid (1076 kg/m3):
– Total module volume (1.42 mL): • 1.6 gram CO2 total
• Vacuum volumes (Eddy Jans memo, 5 November 2009) :– Secondary: 450 liter– Primary: 1715 liter– Maximum dP=10 mbar
• Loosing 1.6 gram of CO2 in the secondary volume gives a density of 1.6 g / 450 l = 3.5 g/m3
– 3.5 g/m3 density after warming up to 20’C gives a pressure of 1.9mbar
– Direct expansion without heat pick-up is ca half of the pressure
1 branch leakage is not problematic when proper shut-off
Possible shut-off concepts
9
No return valve option
• This concept requires small passive no return valves.
• Actuator can be out of the tertiary vacuum • Inlet manifold will be leaked into the vacuum as well:
– Assuming a 4x0.7 tube & 1m long– Extra Volume: 5.3 ml = 5.7 gram– Pressure in secondary vacuum @ 20’C = 8.9 mbar13
1 Active NC valve needed and many miniature no return valves
Red volume will leak in vacuum
Green volume can stay pressurized. An additional pressure relieve can be included
Ambient Tertiary vacuum Secondary Vacuum
Valve is NC and actuated when a pressure increase in the Velo is detected. Eg. 1e-3mbar
Individual inlet shut-off
• This concept requires small passive no return valves.• 26 actuators in the tertiary vacuum
– Pneumatic valves very complex in a vacuum– Electrical valves NC have a constant heat load on the CO2 inlet
• Small volume leaked into vacuum– Pressure in secondary vacuum @ 20’C = 1.9 mbar
14
26 Active NC valves needed in vacuum and 26 miniature no return valves
Red volume will leak in vacuum
Green volume can stay pressurized. An additional pressure relieve can be included
Ambient Tertiary vacuum Secondary Vacuum
Valves are NC and actuated when a pressure increase in the Velo is detected. Eg. 1e-3mbar
Full active shut-off
• This concept is very sensitive for trapping cold liquid– Each line needs a relieve mechanism– Open relieve mechanisms (Burst disc or safety valves) are a risk for the
modules (sudden cool dow n w hen activated)– A w arm safety volume is an option
• 52 Actuators in the tertiary vacuum– Pneumatic valves very complex in a vacuum– Electrical valves NC have a constant heat load on the CO2 inlet
• Small volume leaked into vacuum– Pressure in secondary vacuum @ 20’C = 1.9 mbar 15
52 Active NC valves needed in vacuum
Red volume will leak in vacuum
Green volume can stay pressurized. An additional pressure relieve can be included
Ambient Tertiary vacuum Secondary Vacuum
Valves are NC and actuated when a pressure increase in the Velo is detected. Eg. 1e-3mbar
Safety volume always contains warm gas
No-return valves or active valves are under consideration.
CO2 pumping in secondary vacuum
10
10-2
10-1
100
101
102
103
10-4
10-3
10-2
10-1
100
101
Pressure (mbar)
Mas
sflo
w (
g/s)
ACP28 CO2 pumping capacity
Pressure (mbar)
Mas
s flo
w (
g/s
)
ACP 28 pumping capacity for CO2
A constant CO2 leak of 0.1 g/s is tolerable (Almost a full microchannel flow)
At least 1 ACP28 pump is active, sometimes 2 work in parallel
Proposed test set-up
11
395 liter (Current Velo = 450 liter, upgrade will likely to be less due to smaller hood)
PT,TTTT
PT,TT
PT,TTPT,TT
TT
Condensed reference volume Condenser to regulate CO2 temperature to be vented
Borrowed from Nikhef
FT
Concept Evaporator P&ID
12
PV110
nc
TT35036
To UT-Detector
30
30
60
52
EH39052TT39052
CV39052 EH30036 CV30038 PV30038
NV30142
NV30148
NV30242
NV30248
NV30342
NV30348
nc
nc
EH35036 CV35038 PV35038
NV35142
NV35148
NV35242
NV35248
NV35342
NV35348
PV35052
nc
PV35040
nc
PV35050nc
PV39060
nc
PV39030
nc
PV30040
nc
PV30050
PV59032PV59054
PV49060
PV49030
nc
nc nc
36
PT35052TT35052BD35052
52
PT35038TT35038
38
SA35052
SA30052
PT30038TT30038
38
Safety vent
By-pass with dummy load
Pre-heater
Safety vent
Pre-heater
nc
PV35052
52
PT30052TT30052BD30052
TT39032PT39032BD39032
32
TT30036
36
60
PT39058TT39058BD39058
58
VacuumAmbient
13
Carel valves for CO2 applications
Manual valves we generally use
The Carel vales for CO2 well cover our application range. A manual knob is also available
Q = ca. 100xCv (kW) for dP=15 bar
21 kW
4.9 kW
1.1 kW
Valve sizing
• Flow distribution concept: – DP control of main liquid flow via by-pass– MF control of individual branches with a fixed DP
• To select the proper valve a Matlab simulation tool is set-up– Example shown for Lucasz plant.
• Evaporator data of velo and UT is needed to calculate LHCb plant case 14
0 2 4 6 8 10 12 14 16 18 200
10
20
30
40
50
60
70
80
90
100
Loop massflow (g/s)
Pre
ssur
e dr
op (
bar)
, V
alve
ope
ning
(%
)
LUCASZ LOOP OPERATIONAL SPACE. Quantity of loops:1xLoop control valve: E2V09, By-pass control valve: E2V05
Psp = 17 bar, dPsp = 30 bar, Pmax = 70 bar, Pint = 80 barPump type LDC1 (Velo type), VF = 62.69 lph
Stroke = 12.7 mm, Dcyl = 25 mm, Speed = 168 rpm
Loop Operational Area
Interlock Zone
Manifold Differential PressureBy-Pass Valve Opening
Requirement (MF=14 g/s, dP=20 bar
FT
Control Valve
Control Valve
Control Valve
DP
FT
Controlled liquid flow
Controlled liquid flow
Common 2-phase return
Constant flowFlow control
Flow control
DP control
Conclusions
• The discussions with the VELO about the cooling / safety configuration are progressing, people start to focus towards the same direction– Safety system study at CERN?
• Most input for system manifold is arriving, so concept can progress sufficiently for sizing towards transfer line and plant
15