1. Process Requirements and Design Approach
Vishy Ravindranath
LCLS-II 2 K Cold Box PDR
September 27, 2016

2. Outline 2 K Cold Box Location
Inputs for Process Model: LCLS-II Heat Loads & Pressure Drop Calculations
2 K Process Model
2 K Cold Compressor Requirements
2 K Cold Box Design – P&ID, Interfaces, Utilities & Engineering Standards
LCLS-II 2 K CBX PDR, Sept 27, 2016

3. Requirements Overview –First Light & Normal Beam Operations
1 Cryoplant
2 Cryomodule Strings
U-Tube Connections
14 MV/m Gradient
2E10≤ Qo ≤3E10
Compressor System
4.5 K
Coldbox
LHe
Dewar
2.0 K
Norm Beam Operations
2 Cryoplants
2 Cryomodule Strings
U-Tube Connections Removed
Gradient - 16 MV/m
2E10≤ Qo ≤3E10
Compressor System
He Gas Tanks
4.5 K
Coldbox
LHe
Dewar LN 2
Dewar
2.0 K
Coldbox
U-TUBE JUMPER CONNECTIONS - IB IB
Gas Header
Interface Box 1 4 5 6 7 8 9 10 11 12 13 14 15 BC
Upstream Distribution Box
Downstream
Distribution
Box 2 3
Downstream Distribution Box LH FC
Upstream String L
Downstream String
1.3 GHzGHz Cryomodule
End Cap/Feed Cap
Cryogenic
Bypass
Cryogenic Transfer
Line .
3.9 GHz Cryomodule
Cryoplant IB
Vacuum
Barrier 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 17 18 16

4. 2K Cold Box Location -Cryo-Module to CDS
LINAC CRYOMODULES
Up-stream LINAC
17 CM x 12 m ~200 m
Down-Stream LINAC
20 CM x 12 ~ 240 m
TUNNEL Transfer Lines
LH BYPASS
Length = 70 m; 90° ELBOWS = QTY : 4
BC1 BYPASS
Length = 60 m; 90° ELBOWS = QTY : 4
VERTICAL TL
LENGTH = 11 m ; 90° ELBOWS = QTY : 2
Distribution box
90° ELBOWS = QTY : 6

5. 2K Cold Box Location-CDS to Interface Box
Compressor Room 1
Compressor Room 2
Cold Box Room
2 CDS Transfer lines
Multichannel Transfer Line from CDS to Interface Box
Transfer line length in the Klystron gallery ~ 50 m
Transfer line Length from Klystron gallery ~ 30 m
No of Elbows = 2

6. 2K Cold Box Location-Interface Box to 2K Cold Compressor
9 1/4” Bayonnet Connections for Line B
Interface Box (U-Tube Connections) for connecting the LINAC strings to their respective cryoplants
Pipe Length = 5 m
90° ELBOWS = QTY : 4
Transfer line from Interface Box/Cans to 2K Cold Compressor
Pipe Length ~20 m

7. LCLS-II Cryomodule Heat Load at 2.0K
REF: (1) SLAC LCLSII-4.5-EN-0179-R2, “Cryogenic Heat Load”.
(2) Tom’s Excel Spread Sheet: “LCLScryoHeat-23Feb2016-FirstLight.xlsx”
Tables show the “2.0 K Heat Load” (does not include the heat load on distribution system)
A. First Light Configuration
E = 14 MV/m, Qo = 2.7E10
E = 14 MV/m, Qo = 2.0E10
E = 14 MV/m, Qo = 3.0E10
Up-stream
Down-Stream
Total
Static [kW]
0.158
0.186
0.344
Dynamic [kW]
1.100
1.200
2.300
1.462
1.608
3.070
0.968
1.083
2.051
Total [kW]
1.258
1.386
2.644
1.620
1.794
3.414
1.126
1.269
2.395
B. Normal Beam Operation
E = 16 MV/m, Qo = 2.7E10
E = 16 MV/m, Qo = 2.0E10
E = 16 MV/m, Qo = 3.0E10
Up-stream
Down-Stream
Total
Static [kW]
0.158
0.186
0.344
Dynamic [kW]
1.415
1.615
3.030
1.878
2.146
4.024
1.261
1.464
2.725
Total [kW]
1.573
1.801
3.374
2.036
2.332
4.368
1.419
1.650
3.069
E = 19 MV/m, Qo = 2.0E10
E = 19 MV/m, Qo = 3.0E10
2.569
2.987
5.556
1.717
2.024
3.741
2.727
3.173
5.900
1.875
2.210
4.085

8. LCLS-II Non-Cryomodule Heat Load at 2.0K
UPSTREAM NO
Description
SUPPLY-LINE A
RETURN-LINE B
Temp [K]
Q_Nom [W]
Q_Max [W] 1
Surface TL- Cryoplant to CDS
4.5
6.30
8.19
3.5
45.00
58.50 2
Male and Female Bayonnets Between Cryoplant & CDS [QTY = 4]
4.00
5.20
50.00
65.00 3
CDS- Distribution Box
2.1
27.00
35.10 4
Tunnel TL- LH Bypass
2.5
4.80
6.24
17.26
22.44 5
Tunnel TL-BC1 Bypass
4.30
5.59
15.30
19.89 6
Tunnel TL-Vertical
2.20
2.86
9.32
12.12 7
Tunnel TL-Within Cryomod
3.15
4.10
8.50
11.05 8
Feed Caps
25.00
32.50 9
End Caps
5.00
6.50
TOTAL
71.18
224.09
DOWNSTREAM NO
Description
SUPPLY-LINE A
RETURN-LINE B
Temp [K]
Q_Nom [W]
Q_Max [W] 1
Surface TL- Cryoplant to CDS
4.5
6.30
8.19
3.5
45.00
58.50 2
Male and Female Bayonnets Between Cryoplant & CDS [QTY = 4]
4.00
5.20
50.00
65.00 3
CDS- Distribution Box
2.1
27.00
35.10 4
Tunnel TL-BC2 Bypass
 2.5
2.22
2.89
9.32
12.12 5
Tunnel TL-Vertical 6
Tunnel TL-Within Cryomod
3.15
4.10
10.00
13.00 7
Feed Caps
5.00
6.50 8
End Caps
TOTAL
36.26
195.83
Heat Load on the 2.0 K RETURN LINE-B only contributes to raising the inlet temperature cold compressor suction
REF: (1) LCLS-II CDS HEAT LEAK ANALYSIS, LCLS-II-495-EN-0299
(2) Bayonnet Heat Load calculated by Shirley Yang, 11/13/2015

9. LCLS-II Pressure Drop in LINE-B (Example for E=16 MV/m & Q = 2.7E10)
Nominal Beam Operation E = 16 MV/m, Q = 2.7E10
LINAC SAT TEMP = 2 K
Location
Item
QTY
NPS
PIPE ID
Area
Length
Press_in
Temp
Flow ρ
Velocity mu
Rey No F K
Roughness DP in
m^2 m
Bar
kg/s
kg/m^3
m/s
Pa-s
bar
mbar
Cryomod to CDS
Straight Pipe
1.00
10.00
10.48
0.06
350
0.0313
2.1
0.097
0.75
2.32
5.41E-07
8.58E+05
0.0145
4.60E-05
3.86E-04
0.386
90° Elbow
16.00
8.00
8.41
0.04
0.0309
0.74
3.66
1.07E+06
0.45
3.56E-04
0.356
Elevation 11
0.0306
0.73
2.38
7.90E-04
0.790
2-4K HEX
6.00E-04
0.600
CDS to IBOX 80
0.0292
3.5
0.093
0.41
4.12
8.93E-07
4.98E+05
0.0152
1.57E-04
0.157
2.00
0.0290
0.40
6.44
6.21E+05
7.52E-05
0.075
Bayonet 90° Elbow
4.00
8.36
0.0289
6.53
6.25E+05
1.54E-04
0.154
Bayonet pipe 5
0.0288
6.57
0.0153
3.11E-05
0.031
0.0287
0.18
12.72
1.21E+06
5.83E-04
0.583
0.0282
0.39
12.99
0.0147
1.15E-04
0.115
IBOX TO CC 20
0.0281
0.72
4.47
9.64E+05
0.0144
1.45E-04
0.145
SR 90° Elbow
7.00
0.0279
4.49
4.24E-04
0.424
3.6
0.0275
0.71
4.55
2.51E-04
0.251
TOTAL ΔP [bar]
4.07E-03
[bar]
2.72E-02
Inputs needed for pressure drop estimation:
Pipe Lengths
Elbows
Pipe ID
Upstream pressure
Fluid temperature
Pressure Drop from Linac to CDS = 2.13 mbar
Pressure Drop from CDS to 2 K Cold Box = 1.94 mbar
Total Pressure Drop = 4.07 mbar

10. 2.0 K Process Model, E = 16 MV/m, Qo = 2.7E10
UPSTREAM LINAC
Heat Input defined for LCLS-II (for various Qo & E) were used as input for the 2 K process model
Cryomodule Heat Load
E = 16 MV/m, Qo = 2.7E10
Up-stream
Down-Stream
Total
Static
0.158
0.186
0.344
Dynamic
1.415
1.615
3.030
1.573
1.801
3.374
The process model establishes the process conditions at the suction of the 2.0 K Cold Compressor.
Flow : 97 g/s
CC suction Press. = 27 mbar
CC suction Temp. = 3.6 K

11. Cold Compressor Requirements & Operating Modes
Operating Modes Specified in “Technical Specification for 2K Cold Compressors for the LCLS-II at SLAC National Acclerator Laboratory”, Specification NO: S001, Rev B.
Cases
Mode
Flow [g/s]
Inlet Temp. [K]
Inlet Press. [mbar]
Outlet Temp. [K]
Outlet Press. [bar]
Baseline
Max.
215
3.5 27
< 30
1.2
Nom.
157
3.6
Min.
150 28
Downgrade
135
120
100
“Baseline” configuration will have compressor stages CC0 through CC4
For the “Downgrade” configuration:
CC0 will be bypassed by adding a pipe spool piece connecting to the suction of CC1 (CC1 now becomes the 1st Stage).
New stage CC5 will be added as the last stage compressor and pipe spool piece will used for connecting CC4 to the suction of CC5

12. LCLS-II 2.0 K Heat Load Compressor Map for 1st Stage-Baseline
Compressor Map for 1st Stage-Downgrade
 Description
First light
Normal operation
Gradient (MV/m)
E = 14 MV/m
E = 16 MV/m
E = 19 Mv/m
Quality Factor, Q0
2x1010
2.7x1010
3x1010
CM 2 K Heat load (kW)
3.419
2.644
2.395
4.369
3.374
3.069
5.899
4.085
Flow from a Linac Seg to CDS (g/s) 93 75 68
115
92.5 85
155
110
2.0 K flow in single 2K box (g/s)
186
150
136
185
170
CPs needed 1 2
CCs
Baseline
Downgrade
Heater in CM
OFF ON
CC Suction pressure (mbar)
27.2
28.3
28.6
27.7
24.7
27.4
CC Suction temperature (K)
3.56
3.67
3.73
3.47
3.6
3.38
3.49
Non Dimensional Flow Rate, Qad
1.17
0.92
0.83
0.95
1.16
1.06
1.05
0.90

13. LCLS-II Base Line Design
Pump Down Path
LCLS-II Base Line Design
LCLS-II Downgrade
The process conditions at the suction of the 1stage compressor during pump-down have been provided to the vendor.
The detailed pump-down path will be provided at the FDR for the cold compressors.
2K Cold Box Design Review 24 Aug 16

14. Design Status – Cold Compressors Specification Released
Technical specification includes:
Scope of work…hardware, reviews, schedule, utilities, engineering standards & Requirements for Operating Modes.
Technical Data for compressors, motors, variable frequency drives, instrumentation.
Repair & Maintenance Plan & Past performance history

15. 2 K Cold Box Design Approach - General
LCLSII requirements very similar to FRIB 2K cold box design that is underway at JLab
Cold compressors procured to spec-“Technical Specification for 2K Cold Compressors for the LCLS-II at SLAC National Acclerator Laboratory”, Specification NO: S001, Rev B.
Cold box fabrication procured by build to print

16. 2 K Cold Box P&ID LHe Dewar Clean up return To 4.5K CBX Instrument Air
Sub-atmospheric pressure He gas from cryomodules returns to the suction of CCs and is compressed from ~ 27 mbar to 1.2 bar in the 2 K coldbox. The compressed gas returns to 4.5K coldbox through an U-tube.
For the test of 2 K CBX with LHe dewar, 4.5K cold vapor from LHe dewar is used to simulate the flow, with a 3 kW heater for controlling the helium temperature in the suction line.
A bypass line for the overall CC train is included for 4.5K standby operation mode and pumping down.
Safety valves are used for the protection of the 2 K coldbox, CC and process piping.
Pressure and temperature measurement are installed at the suction of each CC and on the discharge pipe.
A flow meter is installed in the discharge pipe of CCs for flow measurement and controlling of CC.
The 2K coldbox provides vacuum insulation for the cryogenic part of CCs and the cryogenic process piping.
Clean up and warm up piping are included.
Utility piping (Instrument air, cooling water and guard vacuum) are included.
Instrument Air
Cooling water
3 atm He
Guard Vac.
From LINAC CM

17. Operating Temperature
Interfaces
No.
Interface
Connection
Operating pressure
Operating Temperature 1
30 K discharge to 4.5K CBX
5-3/16” bayonet
~ 1.2 bar
25-30 K 2
3.5K suction line
10” internal pipe
weld connection
~ 27 mbar
~3.5 K 3
4.5K vapor from LHe dewar
3-1/8” bayonet
~ 4.5 K 4
Cleanup return
1/2“ internal pipe
weld
300 K 5
RT He supply
1” pipe
4 barg 6
Guard vacuum
Weld
< 10 Torr 7
Instrument air
6 barg 8
Cooling water
2” pipe weld
~ 300K

18. Utilities 1. Electricity 480 VAC +/-24V 3 phase – 60Hz +/-1Hz
2. Cooling water (For CC and Diffusion Pump)
Maximum inlet temperature : 38°C
Maximum return temperature : 49°C
Maximum flow rate per compressor : 0.75m3/h (3.3 gpm)
Pressure drop: <1bar
3. Vacuum guard (For CC and bayonets)
Vacuum will be used for the sealing intercept instead of helium
4. Instrument air
For 5 pneumatic control valves
Supply pressure of 6 barg

19. Engineering Standards
SNO
Topic
CODES
Edition 1
Pressure Vessels-Materials
ASME Boiler & Pressure Vessel Code, Sec. II
2015 2
Pressure Vessels-NDE
ASME Boiler & Pressure Vessel Code, Sec. V 3
Pressure Vessels-Welding & Brazing Qualifications
ASME Boiler & Pressure Vessel Code, Sec. IX 4
Pressure Vessels
ASME Boiler & Pressure Vessel Code, Sec. VIII-Div 1 & Div II 5
Relief Valves
API 520-Part 1, Sizing , Selection , and Installation of Pressur
e-Relieving Devices in Refineries, Part I – Sizing and Selection
2014 6
CGA S-1.3, “Pressure Relief Device Standards Part 3
– Stationary StorageTanks”
2008
Process Piping
ASME B31.3 Process Piping 7
Seismic
LCLSII-4.8-EN-0227, LCLS-II Engineering Note on Cryogenic Plant Seismic Design Criteria 8
Control Valves
ISA-S75.01, Flow Equations for Sizing of Control Valves
2007 9
Flow-Meters
ISO , Measurement of fluid flow by means of pressure differential devices
2003

20. Summary
Specifications & performance requirements for the cold compressors have been developed based on detailed process calculations and used in the Technical Specification for the Cold Compressor- “Specification Number: S001, Rev B”
The cold compressor specification accommodates the anticipated variation in the heat load.
The design & interface requirements for the 2.0 K Cold Box have been clearly identified in the P&ID.
LCLS-II 2 K CBX PDR, Sept 27, 2016

21. Questions ?
LCLS-II 2 K CBX PDR, Sept 27, 2016