1. Physics Requirements for Conventional Facilities
February 2006 Lehman Review

2. Topics
Tolerances
New HVAC Design
New UH Floor Design

3. Tolerances Global Tolerance Optimzation Performed. (See H-D.Nuhn talk)
Weighting factors adjusted to ease difficult tolerances at the expense of easy to meet tolerances.
Parameter pi
Typical Value
rms dev. dpi
Note
KMMF
3.5
0.0003
±0.015 % uniform aK
°C-1
°C-1
Thermal Coefficient DT
0 °C
0.32 °C
±1.0 °F uniform bK
mm-1
mm-1
Canting Coefficient Dx
1.5 mm
0.05 mm
Horizontal Positioning

4. Worst Case - no reliance on position monitoring system
Correction Zones*
Zone 1 (non-invasive correction)
120-Hz traj-feedback (LTU BPM’s)
0.1-Hz traj-feedback (und. BPM’s)
Zone 2 (Dt > 1 hr, P/P0 > 90%, non-invasive)
MICADO (best 5) steering within undulator
Zone 3 (Dt > 24 hr, P/P0 > 75%, invasive)
Weighted steering of undulator traj. (1 min.)
... or quadrupole gradient scans - fast BBA (10 min.)
Possible x-ray pointing (few min.)
Zone 4 (Dt > 1 wk, P/P0 > 50%, machine time)
One iteration of BBA (<1 hr)
Zone 5 (Dt > 6 mo, shut-down)
Reset movers set to zero and manual realignment (1 wk)
Full 3 iterations of BBA (~3 hrs)
Worst Case - no reliance on
position monitoring system

5. New UH HVAC Design
Motivated by a relaxed temperature tolerance of ±1˚F
Two AHUs in parallel, supply 20 ˚C air to tunnel through duct.
Air is returned to the AHU’s and recirculated
1 thermal zone

6. Analyses Performed Four independent analyses were carried out
SCS Solutions, Sunnyvale CA
B. Worek, University of Illinois, Chicago
S. Sharma, APS
J. Welch, SLAC
All used same basic 1-D model, but used different estimates of loads, which reflected a realistic range of conditions and uncertainties in heat transfer rates.
1-D means the net air temperature depends on balance of cooling (walls, etc) and heating (equipment, lights, etc.) loads.

7. Prediction - Normal Running
Tunnel air is expected to be well within spec during normal operations
Lights are assumed to be off or on low during normal operation.
Adapted from SCS Solutions Report

8. Adapted from SCS Solutions Report
Prediction - Access
During access, the air is marginally within spec for normal operation, but well within spec for undulator temperature range (±5 ˚C)
Main effect is due to lighting, assumed to be on fully during access
Adapted from SCS Solutions Report

9. Loads
Loads were divided into Undulator Loads and CF loads and carefully inventoried.
Most important loads were
Wall and floor
Lighting
Undulator equipment

10. Undulator System Loads

11. CF Loads Lighting Walls and floor Chilled water lines LCW lines
Power lines
Supply duct, including friction
Signs

12. Ground Temperature Important input to wall cooling effect.
Ambient ground temperature expected to be about 18.0 C.
Variation during year of order 0.2 C.
From C. Williams, Heat Flow Studies, Earthquake Hazards Team, USGS, Menlo Park ,Ca

13. Heat Transfer Coefficient
Tunnel
Air
velocity
From SCS Solutions Report

14. Wall Temperature vs Time
Steady state temperature depends somewhat on assumption of heat transfer coefficient, h.
Net heat flux is relatively insensitive to h. A factor of 4 increase in h leads to only 30% higher cooling rate.
From SLAC Report

15. HVAC Upgrade Path
If new loads or tighter control is required in future there is a practical means to deal with it.
Chilled water lines pass through the UH to provide cooling to the SBs in the research yard
Valve pairs will be placed every 40 ft to allow tapping the chilled water. Excess capacity exists.
The tapped water can be routed to fin cooled heat exchangers if an constant cooling load is desired.
If more control is needed, a heater can be put in series with each fin cooled unit and controlled with temperature feedback.

16. New UH Floor Design Abandoned scheme with isolated floor slab
Adopted simple, conservative scheme, which should perform as well as existing tunnels
Remaining differential settlement will be dealt with by the WPS and HLS monitoring systems.

17. Summary
UH HVAC design was greatly simplified. Thorough analyses indicate it should work well. Heat load budget needs watching. Upgrade potential is good.
Global tolerance analysis was performed and yielded relaxed temperature tolerance for UH.
A simple, conservative, UH tunnel floor design was chosen. Ground motion will be dealt with by the HLS and WPS monitoring systems. (See C. LeCocq, Wed. 8:00 am and F. Peters, 1:00 pm, Redwood B)