01 - Cryogenics - Nakai

7/23/2019 01 - Cryogenics - Nakai

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NAKAI Hirotaka

Accelerator Laboratory,

High Energy Accelerator Research Organization (KEK)

Tsukuba, Japan

SRF 2013 Tutorials

20 September, 2013



20130920 SRF 2013 Tutorials - Cryogenics: Nakai, KEK

1. Introduction

Superconducting RF cavities and cryogenics

2. Helium refrigerators

Thermodynamics of helium liquefaction

Liquefiers and refrigerators

3. Superfluid helium and cryogenic systems

Superfluid helium (He II)

Superfluid helium cryogenic system

2 K cryogenic systems at KEK

4. Cryogenic Engineering

Cryomodules

Transfer Lines

5. Summary

2




Cryogenics - Science and engineering

concerning with low temperature Low temperature - below normal boiling point

temperature of oxygen (~ 90 K) or

nitrogen (~ 77 K)

4



20130920 SRF 2013 Tutorials - Cryogenics: Nakai, KEK 5

Nb : Tc = 9.3 K




0 20 40 60 80 100

Temperature [K]

NbNbTi

Nb Sn3

He4

n-H2

NeN2

CO

F2

Ar

O2

T c




0.0

0.5

1.0

1.5

2.0

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

1.3 GHz, Rres

= 8x10-9

W

509 MHz, Rres

= 3.3x10-8

W

S u r f a c e R e s i s t a n c e [ x 1 0 - 7

W ]

Temperature [K]




QH = QL +W R

QH

T H

! Q

L

T L

W R !QL

T H

T L"1

#

$ %&

' ( = QL )b

QH

QL

T L

W R

T H

R

Cited from Lebrun, Ph., “An Introduction to Cryogenics”,CERN/AT 2007-1 (2007)

Carnot factor : b =

T H

T L!1

T H = 300 K , T

L= 4.5 K

QL = 1 W W

R ! 65.7 W




1.2 1.4 1.6 1.8 2.0 2.2 2.4

Carnot FactorCavity Loss

Cooling Power

A r b i t a r y S

c a l e

Temperature [K]




A A' C B B'

V A

V B

P A PB

Porous Plug

Cited from I. Oshida and T. Fujishiro, “Thermodynamics”, Shokabo Publishing (1970) in Japanese

External work :

First law of thermodynamics :

Adiabatic condition :

Increased internal energy :

Enthalpy (Gibbs’ heat function) :

Q = 0

U B!U

A= P

AV A! P

BV B

W = P AV A! P

BV B

U + PV = const . = H

Q = U B!U A( ) !W




m =!T

!P

!

"####

$

%

&&&& h

=

V

c p

a T '1( )




0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0 10 20 30 40 50

P r e s s u r e

[ M P a ]

Temperature [K]

Critical Point

m > 0

m < 0

Cited from Verein Deutscher Ingenieure, Lehrgangshandbuch Kryotechnik (1977)




T e m p e r a t u r e [ K ]

300

280

260

240

220

200

180

160

140

120

100

1507

1424

1340

1256

1172

1089

1005

921

837

754

1 . 0

1

0 . 5

0 7

0 . 2

0 3

0 . 1 0 1

5 . 0

7

3 . 0

4

2 . 0

3

P [ M P

a ]

H [J/g]

20.9 25.112.6 16.7 29.3

Entropy [J/g·K]

586

670


100

95

90

85

80

75

70

65

60

55

5020.9 25.112.6 16.78.37 29.3

Entropy [J/g·K]

502

461

419

377

335

293

H [J/g]

1 . 0 1

0 . 5 0 7

0 . 2 0 3

0 . 1 0 1

5 . 0 7

3 . 0 4

2 . 0 3

P [ M P

a ]

T e m p e r a t u r

e [ K ]

50

45

40

35

30

25

20

15

10

5

0 20.9 25.112.6 16.78.374.19

Entropy [J/g·K]

251

209

167

126

83.7

41.9

33.525.116.73.56

1 . 0

1

0 . 5

0 7

0 . 2

0 3

0 . 1

0 1

5 . 0

7

3 . 0

4

2 . 0

3

P [ M

P a

]

H [J/g]

Cited from S. Tanuma ed., “Cryogenics”, Kyoritsu Shuppan (1974) in Japanese




G

K

I

I'

E

H2

C

F

J H3

H4

H1

P1PcP2P3

T c

T e m p e r a

t u r e

T

Entropy S

Isobars ( P > P > P > P )2 c 13

Isenthalps

( H > H > H > H )1 32 4

IsothermalCompression

IsentropicExpansion

IsenthalpicExpansion

AdiabaticExpansion

Cited from S. Tanuma ed., “Cryogenics”, Kyoritsu Shuppan (1974) in Japanese




T300 K

61.3 GPa

0.13 MPa

4.5 KS

8.2 GPa

3.89 J/g·K 8.07 J/g·K

Cited from Lebrun, Ph., “An Introduction to Cryogenics”, CERN/AT 2007-1 (2007)




T e m p e r a

t u r e

Entropy

A

B

C

C'

D

PressureP1

P 2 ( < P1 )

Enthalpy Hisobaric

(heat exchanger)

isentropic

adiabatic

(expansion engine)

isenthalpic(Joule-Thomson vaive)





Compressor

.

W c

Joule-Thomson

Valve(JT Valve)

HeatExchanger

(HX)

Liquid

-.

m L

. m

L

. m

L

. m

. m

(4)

(3)(2)

(V)

(1)

(1)

(1)(2)

(3)

(4)

(3')

(4')

(L)

(V)

T e m p e r a t u r e

Entropy

Isobars

Isentalps

C

Linde Cycle




JT Valve

Liquid

(6)

(3)

(V)

Compressor

.

W c

L

. m

-.

m L

. m

L

. m

. m (2)(1)

(1)

HX3

Expander

HX1 HX2

.

W e

e

. m

-.

m e

. m

-.

m e

. m - L

. m

(7)

(4) (5)

(9)

(e)

(8)

(7)

T e m p e r a t u r e

Entropy

(1)(2)

(3)

(4)

(5)

(6)(L)

(e)

(V)

(9)

(8)

Claude Cycle




120 kPa

700 kPa

6.5 kW @ 80 K

80 KCharcoal

Filter

15 MPa

Drier 150 Nm3 /h

0.5 MPa

110 kPa

1.7 MPa 400 kPa

135 kPa

100 m3 x 9 = 900 m3

High Pressure Gas Storage

0.5 m3 x 18 x 4 = 36 m3

120 kPa

Gas Bag

4 Superconducting Cavities at D11 Section4 Superconducting Cavities at D10 Section

SuperconductingCavity Under Test

Multi-channel Transfer Line

Helium Gas Recovery Line

CirculationCompressors(Screw Type)

Recovery/PurifierCompressor

Helium GasPurifier

NitorgenCirculation

System

Nitrogen GasCompressor

Impure Helium Gas

CylindersPure Helium GasCylinders

Liquefied NitrogenStorage Vessel

Liquefied HeliumStorage Vessel

Evaporator

Helium RefrigeratorCold Box

AdsorberCold Box

Intermediate PressureGas Storage Tanks

SubsidiaryCold Box

80 m 3

C1

C2 C4

C3

C5 C6

C A

CB

T4

T5

T1

T2

T3

T

12000 L

50000 L

D10 Test Stand

SuperKEKB Accelerator Nikko Experimental Hall(Underground Tunnel)

To Open Air




Refrigerator Cryostat

Liquid Helium Liquid Helium

Helium Gas (Warm)

OPEN CYCLE REFRIGERATOR CLOSED CYCLE REFRIGERATOR

Helium Gas (Cold)

Liquid Helium

Storage Vessel(Dewar)

Liquid

Helium

CryostatLiquefier

Gas Bag




0

50

100

150

200

250

300

350

400

0 50 100 150 200 250 300

HeliumNitrogenn-Hydrogen

E n t h a l p y ( v o l u m e ) [ M J / m 3 ]

Temperature [K]

77.420.4

4.2

Latent Heat

Sensible Heat

Cited from Verein Deutscher Ingenieure, Lehrgangshandbuch Kryotechnik (1977)

4.2

77.3

Sensible Heat

Latent Heat




4.5 K

18.8 J/g

4.2J/g·K

S

T

Q1

Refrigerator

HeatLoad

Compressor

LPHPT0 = 300 K

T1 = 4.5 K

Q1

1543J/g

23.1J/g·K

300 K

4.5 K

isobar(0.13 MPa)

18.8 J/g

4.2J/g·K

R

S

T

Q1

Liquefier

Compressor

LHe

R

LPHPT0 = 300 K

T1 = 4.5 K

Q1HeatLoad





Saturated VaporPressure Curve

C




0 1 2 3 4 5 6

Saturated Vapor Pressure Curve

Melting Curve

Lambda Line

Gas Pumping

0

5

Temperature [K]

Solid

He II(Liquid)

He I (Liquid)

Vapor

Critical

Point

2.5

0.2

0.1

Normal Liquid HeliumSuperfluid

Helium




Superfluidity

Flowing through capillaries without any

friction

Super Thermal Conductivity

Apparent thermal conductivity about 100

times of that of high-purity copper

Film Flow Flowing in adsorbed layer of helium atoms




Normal Fluid

ComponentSuperfluid Component

Density rn rs

Viscosity m 0

Entropy

TransportYes No

Driven by Pressure Difference Temperature Difference




Total density is sum of those of each component :

Density ratio depends on temperature

Independent flow fields of each component

r = r

s+ r

n

0.0

0.2

0.4

0.6

0.8

1.0

0.0 0.5 1.0 1.5 2.0 2.5

r s

/ r

o r

r n

/ r

Temperature [K]

rn / r

rs / r

l point




Superfluid component flows toward higher temperature region

Normal fluid component flows in opposite direction ofsuperfluid component flow (thermal counterflow) No netflow

Entropy (heat) is transported only by normal fluid component

Apparent large thermal conduction (internal convection)

Cited from K. Yamada and T. Ohmi,

“Superfluidity”,

Baifukan (1995) in Japanese

T+DT T

SuperfluidHelium

A B

ElectricHeater

Superfluid componet flow

Normal fluid component flow

Q




CottonWool

FinePowder

Radiation

SuperfluidHelium

T+DTT

Electric

Heater

SuperfluidHelium

FinePowder

Cited from Donnelly, R. J., “Experimental Superfluidity”, University of Chicago Press (1967)




Thermometer

VacuumInsulation

Superfluid

Helium

Fine Powder(Porous Plug)

Cited from K. Yamada and T. Ohmi, “Superfluidity”, Baifukan (1995) in Japanese




(A) (B) (C)

Cited from Donnelly, R. J., “Experimental Superfluidity”, University of Chicago Press (1967)




NormalHelium

T ~ 4.4 K

SuperfluidHeliumT ~ 2 K

Joule-ThomsonValve 1

Joule-Thomson Valve 2

Compressor (Vacuum Pump)

Heat Exchanger





Entropy [J/(g·K)]

0 5 10 151

2

4

6

8

10

P = 0.1 MPa

P = 1.66 kPa

T = 4.2 K

T = 1.8 K

T = 2.2 K (P = 5.32 kPa)

He II

He I

89 % 62 % (V)(L)

(1)

(2)

(3)

(4)




Superconducting RF Test Facility (STF) Concerning with ILC project

Pulse mode operation

Capture cryomodule (2 x 9-cell cavities) +

STF2-CM1 (8 x 9-cell cavities) + STF2-

CM2A (4 x 9-cell cavities)

Compact Energy Recovery Linac (cERL)

CW mode operation

Injector linac (3 x 2-cell cavities) + Main

linac (2 x 9-cell cavities)




Tunnel Level

Ground Level

Helium Liquefier/ Refrigerator

Cold Box

He IIPot

Gas Return Pipe

Helium GasPumping System

J-TValve

To Gas Bag

He IPot

LiquidHelium

HeatExchanger

Superconducting Cavities

To Open Air

LiquidNitrogen

5K Thermal Shield

80K Thermal Shield

2KRefrigeratorCold Box

Cryomodule




ConnectionBox

EndBox


Ground Level Tunnel Level

Helium Liquefier/Refrigerator Cold Box

2000 LLiquefied HeliumStorage Vessel


Shaft down toTunnel Level

STF2-CM1Cryomodule

CaptureCryomodule

2K Refrigerator Cold Box

2K Refrigerator Cold BoxEnd

Box

Gas Bag

STF2-CM2ACryomodule




Helium Liquefier/

RefrigeratorCold Box

He IIPot


To Gas BagLiquid

Helium

Superconducting Cavities

Cryomodule

To Compressor/ Gas Bag

LiquidNitrogen

To Open Air

He IPot

5K Thermal Shield

80K Thermal Shield

J-TValve

HeatExchanger

2KRefrigeratorCold Box




5K Shield5KCryopanel

Liquid

Nitrogen

Helium Liquefier/

Refrigerator Cold Box

Cold Helium Gas Return

Liquefied HeliumStorage Vessel

(3000 L)

LiquidHelium



80K Shield


Liquefied NitrogenStorage Vessel(10000 L)

He II

80K Shield


He II

He I

Injector LinacCryomodule

Main LinacCryomodule

Precooling LinePrecooling Line

CavitiesCavities


J-TValve

J-TValve

To Open Air

He I




Heat Load

Joule-Thomson

expansion

Subcoolingheat exchanger

Heat Load

Joule-Thomson

expansion


4 . 5

K

R e

f r i g e r a t o r

Liquidhelium

LP HP

4 . 5

K

R e

f r i g e r a t o r

Liquidhelium

LP HP

4 . 5

K

R e

f r i g e r a t o r

Liquidhelium

LP HP

Heat Load

Joule-Thomson

expansion


E l e c t r i c a l

h e a t e r

Sub-atmosphericcompressor

~ 3 kPa

Sub-atmosphericcompressor MP

CC: Cold compressor HP: High pressureMP: Medium pressureLP: Low pressure

CC

CC

CC

CC

CC

1

2

3

ColdCompression

WarmCompression

Mixed (Hybrid)Compression

MPMP

(a) (b) (c)

CC

CC

CC

Cited from Ph. Lebrun and L. Tavian: “The technology of superfluid helium”,

European Graduate Course in Cryogenics Helium Week, WUT & CERN, August-September 2010




Three Modes of Heat Transfer

Conduction

Thin-wall pipe

Low thermal conductivity material

Convection

Vacuum insulation

Radiation Multi-layer insulation (MLI)

51




80 K Thermal Shield

Gas Return Pipe

Vacuum Vessel

Support Post

5 K Thermal Shield




SuperconductingRF Cavity

2K SuperfluidHelium

Supply PipeHigh Power RFInput Coupler

5-8K ThermalRadiation Shield

40-80K Thermal

Radiation Shield

Support Post

Gas ReturnPipe

3 0 0




0 5 10 15

Scale (cm)

Liquid

Nitrogen

LiquidHelium

GasHelium

LiquidNitrogen

Aluminum80K Shield

Glass Fiber Reinforced Polyester

Glass Fiber ReinforcedPlastic Plate (G-10)

Stainless SteelPipe

InsulationVacuum




0 5 10

Scale (cm)

Liquid Nitrogen

Liquid Helium Gas Helium

Aluminum80K Shield

Glass Fiber Reinforced Polyester

Glass Fiber ReinforcedPlastic Plate (G-10)

Stainless Steel Pipe

Insulation Vacuum




Refrigerator Side

CryomoduleSide

5K Shield (A5052)

80K Shield (A5052)

2K Line Support (G10 /Polyester)

5K Shield Support (G10)

80K Shield Support (G10)

3 1

8 t 3

2 4 0 t 2

1 7 0 t 2

ICF34

2K LHe Supply

ICF34

MLI 10 Layers

LN2 14 t0.5

LHe14 t0.5

MLI 10 Layers

MLI 30 Layers

U-Tight Seal H15040

MLI 10 Layers

2K GHe Return76.3 t0.8

17.3 t0.8

14 t0.5

14 t0.5

60.5 t0.8

80K Shield Pipe

5K Shield Pipe

2K LHe Supply Pipe

2K GHe Return Pipe

SS316L TP-SC

SS316L TP-SC

SS316L TP-SC

SS316L TP-SC




Asphyxiation (Anoxia)

Lack of oxygen

Cold and heavy nitrogen gas - lower level

Cold but light helium gas - higher level

Frostbite Low temperature liquid and gas on skin

Appropriate equipments for protection

Explosion

Pressure rise of liquefied gas in closed space

such as vessels and pipes

Evaporated oxygen




1. Superconducting RF cavities and cryogenics

Liquid helium (He I) for 509 MHz RF cavities

Superfluid helium (He II) for 1.3 GHz RF

cavities2. Helium refrigerators

Joule-Thomson expansion (isenthalpic

change)

Inversion curve

Difference of liquefiers and refrigerators

61




3. Superfluid helium and cryogenic systems

Two-fluid model to understand unique

properties of superfluid helium

Helium gas pumping system

J-T valves and heat exchangers

4. Cryogenic Engineering

Cryomodules and transfer lines

Cryogenic hazards

62

01 - Cryogenics - Nakai

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