ESS Cryogenic System Design
Philipp Arnold
Section Leader Cryogenics
www.europeanspallationsource.se
6th Internation Workshop on Cryogenic Operations
November 10-12, 2014
View of the Southwest in 2025
•
Max IV – a national research facility, under construction, opens up in 2015
•
Science City – a new part of town
Malmö
(309 000)
Copenhagen
(1 200 000)
Lund
(113 500)
 MAX IV
 ESS
2
Outline
1) System Overview
2) Cryogenic Design Choices
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–
–
–
–
–
–
Plant and process arrangement
Cryomodule cooling at 2K
ACCP plant staging
LN2 pre-cooling
Helium storage
Heat recovery
Control system
3) Procurement and Tender Evaluation
3
(1) ESS Cryogenic System
Pure Helium
Gas Storage 1
Accelerator
Cryoplant
Standalone
Helium Purifier
20 m3
LHe Tank
5 m3
LHe Tank
Helium Recovery
System
LN2 Storage
Tanks
Cryomodules
LN2 Mobile
Dewars
Target
Moderator
Cryoplant
Test &
Instrument
Cryoplant
LHe Mobile
Dewars
Cryogenic
Distribution
System
Pure Helium
Gas Storage 2
Instruments &
Experiments
Target
Distribution
System
Test Stand
Distribution
System
Cryomodule Test
Stand
Hydrogen
Circulation Box
Hydrogen
Moderator
(2.1) Plant and process arrangement
1 coldbox building, 1 compressor building,
1 plant per job
Combination of warm and cold sub-atmospheric
compression for ACCP
- Highest space and CAPEX savings
- Schedule, budgeting and technical requirements
- Maintainability
- High flexibility for load adaption
- Optimal overall efficiency
Only warm sub-atmospheric compression for TICP
5
(2.2) Cryomodule cooling at 2K
HP line, 300K, 2-20 bar
Purge return, 300K, <1.1 bar
SV relief line <1.1 bar, 4-300K
Helium recovery line, <1.1 bar, 4-300K
SV72
TS supply, 40 K, 19.5 bara
TS return, 50 K, 19.0 bara
He supply, 4.5 K, 3.0 bar
He return, VLP(vapor low pressure)
SV02
CV05
CV63
PT
60
PT
01
CV06
helium guard
header (HGH)
TT
65
HV73
Roughing
pump MPG
TMP
TT
93
TT
61
on HGH
PT
73
PT
PT
72
HV70
RD90
TT
91
PT
04
HV90
Cryomodule
SV90
HV74
PT
TT
94
PT
02
SV91
TT
06
TT
05
RD91
TT
60
SV70
Vacuum
barrier
Jumper connection
Production of 2 K helium in 2 K
heat exchanger and a subsequent Joule-Thomson valve
in each of the cryomodule–
valve box assemblies
SV60
VN01
VN02
Valve Box
SV71
HV60
CV61
CV04
CV62
CV03
CV60
Cryogenic Transfer Line
PT
03
PT
61
TT
64
TT
92
TT
02
TT
40
TT
30
SM
40
PZ
40
PZ
41
TT
20
SM
30
PZ
30
PZ
31
TT
10
SM
20
PZ
20
PZ
21
SM
10
PZ
10
PZ
11
CV01
CV02
TT
01
TT
04
- Heat load on CDS only on 4.5K,
not 2K helium
LT
01
LT
02
beam
CV80
CV81
RF
40
TT
49
TT
42
EH
31
TT
35
AD
41
ED
40
PT
40
FT42 CV42
EH
21
TT
25
AD
31
AD
30
ED
30
PT
30
PS
30
TT
54
TT
29
EH
33
TT
37
FT32 CV32
RF
10
TT
28
TT
11
EH
10
TT
18
TT
19
TT
03
TT
12
TT
13
EH
22
TT
24
EH
11
TT
15
AD
21
AD
20
ED
20
PT
20
PS
20
TT
53
FT31
EH
43
TT
47
EH
20
TT
22
EH
32
TT
34
CV31
PT
70
CV41
FT41
HV71
HV72
TT
21
EH
12
TT
14
AD
11
AD
10
ED
10
PT
10
PS
10
TT
63
TT
52
FT21
AD
40
PS
40
TT
55
PT
71
TT
39
TT
32
EH
42
TT
44
TT
62
PI
70
EH
30
CV21
EH
41
TT
45
TT
31
RF
20
TT
38
space frame
TT
51
- independent warm-up /
maintenance / cool-down of
single cryomodules while the rest
of the system is maintained in
cold condition
TT
50
FT11
EH
40
TT
48
EH
23
TT
27
CV11
TT
41
RF
30
FT22 CV22
EH
13
TT
17
PT
11
TT
16
FT12 CV12
6
(2.3) ACCP plant staging
3500
excl. margin
3000
incl. margin
2K Heat Load [W]
2500
2000
Two sets of flow parts for cold
rotating equipment
-
turbine expanders
-
cold turbo compressors
1500
Variable frequency drive(s) in the
warm LP compressor system
1000
500
0
Total heat load
stage 1
Total heat load
stage 2
Static heat load
stage 1
Static heat load
stage 2
7
(2.4) LN2 pre-cooling
TICP
WITH LN2 PRE-COOLING
ACCP
WITHOUT LN2 PRE-COOLING
-
CM testing: “constant level
liquefaction w/o internal freezeout purification”
-
~80% of the load is at 2K  with
cold compression translated to
4-20K refrigeration
-
Liquefaction for LHe consumers:
“rising level liquefaction w/
internal purification”
-
~20 tons of cold mass max do
not impose tough cool-down
requirements
-
 Turbo-expanders can be
optimized to perform efficiently
in both operation
-
No substantial CAPEX impact
-
Downsides of LN2 usage like
dependency on regular supply
and increased traffic at ESS
more severe
-
Much better plant fit with easy
adapting when higher rate
needed (switch pre-cooling on)
8
(2.5) Helium Storage
Gasbag
(100 m3)
HP Gas Cylinder (12 m3)
16 bottles X 5 bundles X 3 strings
LP line
Empty one bottle
HP panel
MP line
HP line
SP line
Warm Helium
storage tanks
(1) Helium inventory in CMs and CDS
~ 2 tons during normal operation
Impure He line/LP
LN2
GN2
Purge warm tanks
SV relief/LP
Impure He line/HP
Recovery
Compressors
CTL
(2) 20
LN2
GN2
m3
–
–
Adsorption
Dryer
Load or unload the ACCP
GN2
Buffer for TICP
1 X 60 m3
LHe tank as second fill
External
purifier
H
P
GMP
ACCP
15 X 60 m3
FOR&GMP
Facilitate helium management in
transient modes
Power failure return
SP
H
P
FOR
Speed up re-cool-down
L
P
ACCP
15 X 60 m3
Dryer
GN2
SP
L
P
L
P
ACCP
15 X 60 m3
S
P
SP
LN2 Tank
(3) 16 x 60
m3
warm tanks
LN2
To external purifier
GN2
–
Store helium when accelerator warm
–
A little more required for warm parts of
ACCP and higher helium inventory
during 4.5K standby mode / cool-down
Compressor hall 1
LN2 Tank
GN2
For dryer
Duct
Compressor hall 2
Duct
Gallery
SV relief and helium guard
SV relief and helium guard
HP supply
Coupler return & CD/WU, Vacuum insulated
Coupler return & CD/WU, Vacuum insulated
Purge line
Purge line
Helium mass in CMs & CDS
w/o shield[kg]
Heater
GN2
5000 L
LHe tank
1000
CM
500
Heater
Line
Dryer
Mobile
Dewar
LN2
ACCP
Cold Box
Heater
GN2
Test bench
0
20000 L
LHe tank
Vapour
Helium
TICP
Cold Box
Storage station
Conditioning helium guard
HP supply
2000
1500
Conditioning helium guard
Boil-off station
2500
From instruments
LN2
To TICP CB
CM
Liquid
Helium
Cold box hall
NO
LN2
GN2 for drying and regeneration
GN2 for drying and regeneration
End
box
CM
Tunnel
9
CD
Figure 1
Project
Technical Specification of the TICP
(2.6) Heat Recovery
25C
37C
27C
25C
He to fine oil
removal
Compr.
motor
Helium
compressor
Middle
temperature
Supply
83C
39C
He from
cold box
Middle
temperature
Return
32C
27C
90C
85C
Helium cooler
Oil
vessel
90C
85C
27C
32C
Oil
cooler
High
temperature
Return
Middle
temperature
Return
•
No elevated oil or helium temperatures out of compressor
suppliers specs
•
Dedicated cooling water circuit for cryoplant (quality
constraints of available cooling water in the building)
•
Slow temperature control on cooling water side, fast
temperature control on oil side
•
Cooler design state of the art e.g. for Kaeser compressors
•
Cooling function has priority over heat recovery return
10
(2.7) Control System
Functional split between local PLCs and EPICS IOC
•
•
•
Deterministic control loops
Time critical and internal functions
Safety functions
•
•
•
•
•
Supervisory controls
High level batch operations
HMI incl. local SCADA
Alarm handling
Data archiving
 Safe operation even in case the EPICS
IOC shuts down
 ACCP control system is compatible with
the other linac control
 Advantages of an open control system
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(3) How do we get what we want?
Procurement procedures
 open, restricted, negotiated, competitive dialogue
Scope split
 clear interfaces (also during different phases of installation)
 complex systems (rather one integrator) vs. simple systems
Small yet relevant qualitative part in the tender evaluation
 verifiable with proposal
Thorough acceptance testing
 Possibly incentive part for consumption
Sincere and transparent procurement process
Thank you for your attention
12