Transcript MICE LH2 Absorber 1. 2. 3. 4. Assembly Safety Staging Instrumentation March 14, 2003 MICE Absorber/Coil Integration Absorber Design Issues 1. 2. 3. 4. 5. 6. 7. 8. LH2 circulation and heat extraction Monitoring and instrumentation Window attachment Assembly and disassembly: 1.

MICE LH2 Absorber
1.
2.
3.
4.
Assembly
Safety
Staging
Instrumentation
March 14, 2003
MICE Absorber/Coil Integration
Absorber Design Issues
1.
2.
3.
4.
5.
6.
7.
8.
LH2 circulation and heat extraction
Monitoring and instrumentation
Window attachment
Assembly and disassembly:
1. Removability
2. Stabilization
Cryogenic attachments
Temperature stability
1. Insulation of hotter/colder elements
2. Prevention of O2 condensation
Vacuum integrity
Physical modifications and upgrades
March 14, 2003
MICE Absorber/Coil Integration
LH2 Safety Issues
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•
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•
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O2/LH2 separation
No Ignition sources near LH2
Adequate ventilation
Affects:
• Windows: absorbers and vacuum
• Primary and secondary vacuum volumes
• Support structure absorber/focussing coil
• Instrumentation (experiment and monitors)
• Cryogenic operation
• Laboratory area
Cooling concerns:
• Minimizing window thickness/no. of windows
• Uniform heat maintenance of LH2
March 14, 2003
MICE Absorber/Coil Integration
Categories for FNAL LH2 Mucool
Safety Review
1. Civil construction
2. Absorber windows
3. Vacuum vessel windows
4. Safety controls systems
5. Electrical safety of hydrogen areas
March 14, 2003
MICE Absorber/Coil Integration
Safety Codes and Standards for FNAL LH2
FERMILAB STANDARDS (FESHM)
• “Guidelines for the Design, Review and Approval of Liquid Cryogenic
Targets”
• “Liquid Hydrogen System Guidelines”
• “Storage and Use of Flammable Gases”
• “Cryogenic System Review”
• “Oxygen Deficiency Hazards”
• Other…Pressure Vessels, Dewars, Electrical, etc.
NATIONAL CODES
• ASME Code
• National Electric Code
• National Fire Protection Association Code
• Compressed Gas of America Standard
• March
ISA
Application of Safety Instrumented Systems
14, 2003
MICE Absorber/Coil Integration
FNAL Safety Requirements for Windows
Absorber Windows
Design:
•
•
Internal WAMP = 25 psid
FEA showing max. allowable stress < 0.25 UTS (this is waived by
meeting the performance tests below)
•
Material certification
•
Window engineering/design drawing
Tests:
•
Room temperature tests per UG-100 of the ASME code and room
temp. burst test.
•
Liquid nitrogen test – burst test per UG-101 of the ASME code
Note: The LH2 circuit safety relief system includes 2 valves with a 10 psid
March
14,point.
2003
set
In addition, a PLC-controlled
vent valve will be installed
MICE Absorber/Coil Integration
FNAL Safety Requirements for Windows (2)
Vacuum Windows
Assumption: Design assumes that the beampipe attaches to absorber
vacuum windows, therefore vacuum exists on both sides of the windows
Design:
• Internal WAMP = 25 psid
• External MAWP = 15 psid
• FEA showing maximum allowable stress is <2/3 Sy or < 0.4 Su
• Material certification
• Window drawing
Tests:
1. Burst test 5 vacuum windows at room temp. to demonstrate a
burst pressure of at least 75 psid for all samples. (pressure exerted
on interior side of vacuum volume).
2. Non-destructive tests at room temperature: External pressure to 25
psid to demonstrate no failures: no creeping, yielding, elastic
collapse/buckling or rupture
March 14, 2003
MICE Absorber/Coil Integration
FNAL Safety Requirements for Controls
Safety Interlocks (Quadlog PLC) and Controls (Apacs)
Functions:
• Control operations of the LH2 system
• Safety interlocks for the LH2 system
• Safety actions in the case where flammable gas or ODH conditions
are detected
System design:
• Design requires knowledge of equipment value in the experimental
hall
• An estimate of failure severity and frequency will be made as well
as the consequences to personnel and equipment
• The overall risk will be evaluated to determine a “Safety Integrity
Level” (SIL).
• The SIL will determine the safety controls architecture (level of
redundancy required) per ANSI/ISA-84.01, “Application of Safety
Instrumented
Systems for
the Process Industries”
March
14, 2003
MICE Absorber/Coil Integration
MICE Staging and experiment
1.
2.
3.
4.
Filling, cooling and purging cycle
Data acquisition and controls
Absorber variations
Safety triggers and recovery..
1. Magnet quench
2. Cryogenic failure
3. Absorber failure
4. Vacuum failure
5. Upgrades (wedges, H2 gas..)
6. System stability checks
7. Maintenance cycle
March 14, 2003
MICE Absorber/Coil Integration
Instrumentation Safety
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Temperature/density uniformity inside LH2
Safety instrumention inside vacuum area
Detectors for cooling measurements
Safety Issues:
1. Limits the amount of power/(area or vol)
2. Physical size of the signal feedthroughs
3. Distance away from target (e.g. VLPC readouts)
4. Seals from signals to electronics:
wires
fibers
tubes
March 14, 2003
MICE Absorber/Coil Integration