DEE-54030Kryogeniikka

Transkriptio

1 DEE-54030Kryogeniikka Nesteytys ja kryojäähdyttimet

2 hermodynamic Fundamentals SECOND LAW OF HERMODYNAMICS (Relation of work and heat) Kelvin Statement System Hot reservoir Q. Q. W. Q. Surrounding Clausius Statement Surrounding h 0 Of the heat supplied at a high temperature to a system not all can be converted to work; a fraction of it must be rejected as heat at a lower temperature. System c Cold reservoir No process is possible whose sole result is the removal of heat from a reservoir at one temperature and the rejection of an equal quantity of heat to a reservoir at a higher temperature. Refrig9c.cdr

3 Carnot n kiertoprosessi W Q 0 1 ts. W Q 0 c c 1 W Q Q W jäähdytyksen laatuluku (figure of merit, FOM) jäähdytyksen hyötykerroin (coefficient of performance, CO) Kun systeemi koostuu joukosta ideaalisia Carnot n kiertoja lämpötilojen h ja L välillä ja olettamalla ideaalikaasutilanne, jolloin Q = C p d

4 Carnot n kiertoprosessi (Cont.) W H C L 0 p 1 d Kaasun nesteytykseen tarvittava työ = kaasun jäähdyttäminen höyrystymislämpötilaan s + kaasun nesteytys vakiolämpötilassa Siis W R 0 0 s C p d H s s C 0 s0 sl h0 h L p d H

5 Ideal (Carnot) Specific ower Watts of input power per watt of refrigeration Carnots.cdr

6 Domestic / Cryogenic Refrigeration he Basis 1. Do work on a gas to compress it. Do this while the gas is thermally connected to a heat sink so that the gas is compressed isothermally. he gas is now compressed to the compressor outlet pressure and its original temperature. 2. Move the gas to a different location either in space or time. No change in temperature has occured. 3. Expand the gas while it is thermally isolated, causing it to cool. he gas temperature is now lower than when it started and its pressure is back to the starting pressure of the compressor inlet.

7 Domestic / Cryogenic Refrigeration he Basis (Cont.) 4. Move the gas to a different location is space or time. he gas remains at the new, lower temperature. 5. hermally connect the cold gas to the object to be refrigerated. It will inevitably absorb heat from the surrondings. 6. Move the warmed gas to a different location in space or time; specifically, remove it from the object being cooled. 7. Warm the gas to its original temperature and return it to the inlet of the compressor.

8 Isentalpinen laajeneminen Korkeapainepuolesta kompressoitu kaasu laajenee vapaasti matalampaan paineeseen venttiilin tai jonkin huokoisen materiaalin kautta. Kaasu ei tee laajetessaan työtä, prosessi on adiabaattinen ja palautumaton (entalpia ei muutu). Joule-homsonin kerroin J lim 0 H H

9 Nyt H = f (, ) d H d H dh rosessi isentalpinen; dh = 0 H J H H / / Nyt C H H Merkitään jolloin J C 1 Koska dh = ds + V d V S V S H Maxwell: V S

10 Siis V V C C p p J 1 1 Ideaalikaasulle V = R / V R V äten siis 0 1 V V C p J Ideaalikaasu ei siis lämpene eikä kylmene isentalpisessa laajenemisessa!

11 van der Waalsin tilayhtälö a V 2 V b R ideaalikaasulle siis a = b = 0 J- -kerroin J C 2a R 1 1 2a V b V 1 2 b V 2 b Inversiolämpötila ( J- = 0) inv 2a b R 1 b V 2

12 Inversion Curve Gas Max. Inversion emperature (K) Ammonia 1994 Carbon dioxide 1500 Methane 939 Oxygen 761 Argon 794 Nitrogen 621 Air 603 Neon 250 Hydrogen 205 Helium K Inversion.jpg

13 Joule-homson (J) Cycle (hrottle Cycle) ADVANAGES No cold moving parts Steady flow (no vibration) ransport cold long distance Cold end can be miniaturized DISADVANAGES Relies on real-gas behavior Requires high pressures 200:1 (compr. wear) 25:1 with mixed gases ( > 70 K) Small orifice susceptible to clogging Low efficiency below 90 K Icec14c.cdr

14 Joule-homson (J) Cycle (hrottle Cycle) USES (Current and potential) Cooling IR sensors on missiles Cooling IR sensors for surveilance (10 K) Cooling semiconducting electronics Cryogenic catheter (heart arrhythmias) Liquefaction of natural gas RECEN DEVELOMENS Mixed refrigerants Sorption compressors Electrochemical compressors Icec15c.cd r

15 EMERAURE Joule-homson (J) Cycle (Linde-Hampson Cycle) Comparison with vapor-compression cycle W. Compres sor high b' b low a h 7 Q., 0 0 b b' a Aftercooler wo-phase boundary h 6 Heat exchanger c J orifice d c e h 5 Cycles12ca.cdr Q., c Evaporator c h 1 h h 2 2* ENROY d e h 4 Isenthalp h 3 Cycles2.cdr

16 Isentropinen laajeneminen Isentropinen laajeneminen on termodynaamisesti tehokkaampaa kuin isentalpinen laajeneminen, koska kaasu tekee työtä laajetessaan. rosessille voidaan määrittää Joule-homson kerrointa vastaava vakioentropian käyrä - avaruudessa. s S DEE Kryogeniikka Risto Mikkonen

17 ds Koska S = f (, ) d S S äten Koska S S d S C d V S d S d ja Maxwell d S 0 Joten C d Koska nyt ds = 0 C äten d 1 C S V V V d d S S

18 Ideaalikaasulle S C V V R V Verrataan kertoimia H ja S V C V C V V C S H Näin ollen S H C R C V Isentropinen laajeneminen on siis tehokkaampaa kuin isentalpinen laajeneminen.

19 Claude Cycle W. 0 Compressor Q., 0 0 Aftercooler HX1 Steam engine W. e Expansion engine J valve HX2 HX3 Claude Expansion Engine Air liquefaction (1902) 2.5 Ma Q., c c Evaporator Claude2c.cdr G. Claude, Liquid Air, Oxygen, and Nitrogen (1913)

20 Claude Cycle Collins Helium Liquefier Collins He liq schematic.tif 4-8 L/hr Collins He liquefier-adl1.jpg

21 Claude Cycle Modern Helium Liquefier Sulze r Collins-claude.jpg 50 L/hr urboexpanders Heliquefier.cdr

22 Helium Liquefaction lant Linde HERA (DESY, Hamburg) 3 x 10, K heliumplant.cdr

23 otential Cryocooler roblems Reliability Efficiency Size and weight Vibration and noise emperature oscillation Electromagnetic Interference (EMI) Heat rejection Cost DEE Kryogeniikka Risto Mikkonen

24 Heat Exchangers wo ypes RECUERAIVE Separate channels with solid walls separatingthe continuously flowing hot and cold fluids. Fluids usually in counterflow. Hot Q Cold Heat transfer Siemens: 1857 REGENERAIVE A single flow channel filled with a matrix of finely divided material subject to alternating flows of hot and cold fluids. For continuous flow one must have two identical matrices with periodic switching or a disc rotating slowly (thermal wheel) and passing alternately through the hot and cold fluid ducts Stirling: 1816 Refrig7c.cdr Hot Hot Cold Cold

25 Recuperative Cryocoolers W. (Steady Flow) Ẇ 0 0 Q., 0 0 W. 0 Q., Q., J valve Q., c c Ẇ c Q., c (a) Joule-homson (b) Brayton (c) Claude MCALC-III-introduction Heat exchanger c W. c J valve Q., c c csa3c.cdr

26 Stirling Cryocooler ADVANAGES High efficiency Moderate cost Small size and weight Over 140,000 made to date DISADVANAGES Dry or no lubrication Intrinsic vibration from displacer Long lifetime expensive (3-10 yrs) Icec21c.cd r

27 Stirling Cryocooler USES IR sensors High temperature superconductors Satellite experiments RECEN DEVELOMENS Flexure bearings Gas bearings Diaphragm compressor and expander wo-stage cold heads Icec22c.cd r

28 ime emperature ressure Ideal Stirling Cycle Compression space Regenerator a b 0 Expansion space Compression b c 0 a c Regenerative cooling c d d a c Expansion Regenerative heating 0 0 Volume b a a b c d a Displacement c Working fluid: Ideal gas (helium) DEE Kryogeniikka Risto Mikkonen c V d Entropy V 1 2 Stirling ideal 1c.cdr

29 Early hillips Stirling Air Liquefier First developed in 1953 DEE Kryogeniikka Risto Mikkonen Courtesy: G. Walker, Cryocoolers, lenum (1983)

30 Modern Stirling Air Liquefier 5 L/hr LN K K 11 kw input 25% 80 K StirLIN_1_compact.jpg

31 Large Stirling Liquefier 4 cylinders 44 L/hr LN K K 44 kw input 26% 80 K StirlingLpc-4small.jpg

32 New Low-emperature Stirling Cryocooler Single stage cooler operating below 30K Based on existing AIM SL400 cooler K / 100 W input Mass 3,5 kg AIM ingo.ruehlich@aim-ir.de

33 Gifford-McMahon Cryocoolers ADVANAGES High reliability (1-3 yrs) Moderate cost Good service Over 20,000/yr made DISADVANAGES Large and heavy Intrinsic vibration from displacer Low efficiency Icec28c.cd r

34 Gifford-McMahon Laitteisto koostuu suljetusta sylinteristä, jossa kaasun virtausta ohjataan männän avulla sekä virtauskanavan sisältämästä regeneraattorista.

35 Gifford-McMahon

36 Gifford-McMahon (GM) Cryocoolers USES Cryopumps (15 K) MRI magnets (4-12 K) Laboratory magnets R & D labs RECEN DEVELOMENS 4 K operation Rare earth regenerator materials Improved valve timing Icec29c.cd r

37 Gifford-McMahon (GM) Cryocooler System Used for cryopumps Used for MRI shield cooling

38 2-Stage Gifford-McMahon Cryocooler 2nd Stage 1st Stage Low pressure High pressure Electrical GM2stage.cdr

39 Range of Commercial GM Cryocoolers One-Stage Coolers

40 wo-stage 4 K GM Cryocoolers Sumitomo Heavy Industries (SHI) Model 1 st stage 2 nd K Input power (kw) SRDK-415D 45 W@50 K 1.5 W 7.5 kw SRDK-408D2 44 W@40 K 1.0 W 7.5 kw SRDK-408D 37 W@40 K 1.0 W 7.5 kw SRDK-305D 20 W@40 K 0.4 W 4.5 kw SRDK-205D 4 W@50 K 0.5 W 3.4 kw SRDK-101D 5 W@60 K 0.1 W 1.3 kw

41 GM Cryocoolers for MRI Magnets Shield cooling 15 K GM Slide 05.tif

42 GM Cryocoolers for MRI Magnets Zero boil-off 4 K GM Slide 06.tif

43 Magnetic Resonance Imaging (MRI) 1.5 Superconducting magnets 1 W at 4 K Non-magnetic regenerators > K cryocoolers since 1995 Cumulative number of MRI superconducting magnets sold umor

44 Desired 5 K Cryocooler Specifications 5 K Cryocoolers for Electronics Size Rack mountable (19 rack), < 24 inches (60 cm) high Weight <150 lb (70 kg) Cooling ower at 4.5 K 0.25 W Cool-Down ime < 2 hours Input ower < 1 kw (For U.S. Market) emperature Stability < 50 mk Reliability/Maintenance 5 years/1 to 3 years Ambient Magnetic Noise < 1 Gauss Cost < $10,000 in quantities Courtesy of Hypres From 1995 Workshop Hypresspec.cdr

45 GM Cryocoolers for LS Electronics Leybold Coolpower 4.2LAB Sumitomo SRDK-101D-A11C 400 mm K 2.5 kw 1 phase 208/220 V Air or water cooled $20, K 1.3 kw 1 phase 120 V Air cooled

46 Brayton Cycle ADVANAGES Steady flow (low vibration, turbo-expander) Long lifetime (gas bearings, turbo system) ransport cold long distance Good efficiency except in small sizes DISADVANAGES Difficult to miniaturize Requires large heat exchanger Expensive to fabricate Ic ec19c.cdr

47 Joule-Brayton prosessi

48 Brayton Cycle USES (Current and potential) IR sensors for satellites RECEN DEVELOMENS Small turbo expanders and compressors 3.2 mm dia. expander rotor 5 W at 65 K with 43 W/W Heat exch.: 90 mm dia x 533 mm long Icec20c.cd r

49 700 mm NICMOS Brayton Cryocooler Hubble Space elescope Creare March 2002 installation 8.0% of Carnot 7.7 K 315 W input NICMOS2.cdr

50 Regenerator Volumetric Heat Capacity emperature (K) Heat Capacity03.tif

51 Regenerator Materials Sphere porosity = 0.38 Irregular particle porosity > 0.50 Er 3 Ni spheres developed by oshiba in 1989 Kuriyama, et al. reached 4.5 K in 1989 Ushered in development of 4 K GM and cryocoolers

52 rogress of Multilayer Regenerators Volumetric specific heat.jpg Multilayer regenerator.jpg

53 ulse ube Cryocoolers ADVANAGES Highest cryocooler efficiency for 40 K<<200 K No cold moving parts Higher reliability Lower vibration and EMI Lower cost DISADVANAGES Short history (OR since 1984) Gravity-induced convective instability Lower limit to size for efficient pulse tube Icec23ca.cdr

54 Reservoir NIS Mini ulse ube Experimental System Needle Valve (orifice) K 4 cc compressor ulse ube Regenerator Mini pt 01.jpg

55 Mini ulse ube Cryocooler for Space Applications 0.62 W at 80 K 20 W input power Space applications 1.3 kg Lockheed Martin

56 Large GM-ype ulse ube Cryocooler Large capacity low frequency coaxial pulse tube cold head (left) Final integration on a 40 kva HS transformer demonstrator (right) Buffer volume Rotary valve Warm end ulse tube cold finger coaxial shape Cold tip Courtesy:. rollier Air Liquide 80 K / 5 kw

57 Commercial 4 K ulse ube Cryocooler 0.5 W at 4 K 30 W at 65 K 5.5 kw input power 20,000 hr maintenance 1 Hz frequency (GM type) Cryomech pt405 Cryomechpt405.cdr

58 Head MRI with ulse ube Cryocooler Introduced in 2001 by GE Cryomech R 1 K ulse tube required for low vibration Conduction cooled Nbi GE GeheadMRI02.jpg

59 Integration: Cryocooler roblems Reliability Efficiency Size and weight Vibration emperature oscillation Electromagnetic Interference (EMI) Heat rejection Cost csa10ca.cdr

60 Efficiency Comparisons

61 Heavier Size and Weight Comparisons Density = 0.8 kg/l Mass (kg) = x in (W) General Rank (GM-type) (Stirling-type) (Mixed gas J) (LF) GM J Mixed gas) urbo Brayton (HF) Stirling For fixed cooling power From: H. J. M. ter Brake and G. F. M. Wiegerinck, Cryogenics, vol. 42, (2002) pp

62 Conclusions Improved cryocoolers needed emperatures from 50 mk to 170 K Higher efficiencies, particularly for < 50 K Lower cost very important Cryocoolers used in many applications Enabling technology for such areas as superconductors Improves performance (such IR detectors)