Limits of the current VTCS
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Limits of the current VTCS Ann Van Lysebetten Bart Verlaat Martin van Beuzekom VELO upgrade meeting 14/11/2008 pix module construction kick-off 09/11/2009
description
Limits of the current VTCS. Ann Van Lysebetten Bart Verlaat Martin van Beuzekom. pix module construction kick-off 09/11/2009. - PowerPoint PPT Presentation
Transcript of Limits of the current VTCS
Limits of the current VTCS
Ann Van Lysebetten
Bart Verlaat
Martin van Beuzekom
VELO upgrade meeting 14/11/2008
pix module construction kick-off 09/11/2009
Limits & “bottlenecks”Limits & “bottlenecks”
prim. System H2O 20C
Sec. System (freon)
Tert. System (CO2)
Detector waste heat (max 800W)
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Tert. System (CO2)
Detector waste heat(max 800W)
Heat Transfer to the module!
• Limited by current compressor, freon injection, heat exchanger to CO2
•Max massflow of pumps 18g/s
• Min CO2 temp -30 C
• heat exchanger to freon?
prim. System
air
20 stations * 10 Velopix -> 4 Watts/velopix
= ~ 2W/cm2
T > 15 ‘C
Minimal upgrade allows ~ 6W/cm2Minimal upgrade allows ~ 6W/cm2
prim. System H2O 20C
Sec. System (freon)
Tert. System (CO2)
Detector waste heat (max 2.5kW)
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Tert. System (CO2)
Detector waste heat(max 2.5kW)
• new compressor,
• new freon injection,
• new heat exchanger to CO2
• with CO2 massflow of 18g/s
• min at -35 C
• If necessary new heat exchanger to freon
prim. System
air
But!
• to keep silicon at < -5 C lower temp needed if interface not changed!
Cooling interface• Current cooling interface (cookie) is one of limiting factors• Try to integrate cooling pipe into module
– But, no high pressure connectors in vacuum
-> Orbital welding of module to cooling pipe
Cut here
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SummarySummary Current system can cool up to 800W With some modifications it can reach 2.5 kW -> CO2 cooling plant can do the job! Large T due to large thermal resistance and long path
• this means either lower CO2 temp needed• OUTSIDE range of current system• new freon/CO2 chiller, this has limits! • module on/off temp difference large
Integrate cooling pipe into module/station• shorter path, smaller T over module• small temp differences on/off• connect modules to cooling system via orbital welding
The VTCS cooling principleThe VTCS cooling principle
Con
dens
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PumpHeat exchanger
Flooded evaporator
Restriction
2-Phase Accumulator
He
at
in
He
at
in
He
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ou
t
He
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t
1
2 59
1013
prim. System H2O 20C
Sec. System (freon)
Tert. System (CO2)
Detector waste heat (max 800W)
Tertiary System: two phase accumulator controlled system
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Tert. System (CO2)
Detector waste heat(max 800W)
Fre
on
sy
stem
prim. System
air
SP -25C
