Susana Izquierdo Bermudez. 29-04-2014 11T and QXF are pushing the boundary of protection we need a good understanding of the.
Download ReportTranscript Susana Izquierdo Bermudez. 29-04-2014 11T and QXF are pushing the boundary of protection we need a good understanding of the.
Susana Izquierdo Bermudez. 29-04-2014 11T and QXF are pushing the boundary of protection we need a good understanding of the dominating physics Very different time and space scales Different strongly coupled physics domains Important dependence on very non-linear material properties Let’s try to understand it bit by bit… Longitudinal quench propagation Heat transfer within the coil Important because it determines the time needed to detect a normal zone Important because it determines the time needed to quench the whole magnet cross section Heat transfer from heater to coil Important because it defines the time needed to induce a distributed quench 2 Models overview ROXIE QUENCH MODULE [Sch 2010] Couples magnetic, electrical and thermal. First order thermal network (2D (XSec) + 1 (z*)) SUPERMAGNET [Bot 2007] Built by different blocks with an unified interface for data exchange. THEA [Bot 2010] Thermal, Hydraulic and Electric analysis of superconducting cables Adaptive mesh tracking *Requires small element size (<1mm) in the longitudinal direction to converge in terms of longitudinal quench propagation velocity T Quench Propagation Speed (m/s) Under the same assumptions…very close propagation velocity (not the case for Tmax!) Mesh density 25 THEA ROXIE 20 HEATER [Bot 2010] FE heat conduction 15 10 POWER [Bot 2004] 5 Electric network simulation of magnetic systems 11T, I=11850 A 0 2 7 B [T] 12 3 Modelling: Thermal Coupling 𝜌𝐶𝑣 𝑇, 𝐵 First Order Thermal Coupling 𝑑𝑇 = 𝑄 𝑗𝑜𝑢𝑙𝑒 + 𝛻 ∙ (𝑘 𝑇 (𝑇, 𝐵)𝛻𝑇) 𝑑𝑡 Higher Order Thermal Coupling Hybrid model [Gav 1992] Option 1 Cp=Cpcond Option 2 Cp=Cpcond+Cins FE mesh (insulation) Conductor Coupling [ROXIE] Cu+SC Insulation Heat capacity Thermal resistance 4 Modelling: coupling heat conduction domains HEATER : Heat conduction in the insulation is solved in 2D cross sections THEA: Thermal and Electrical analysis of the superconductor cable Δz 2D quadrilateral elements with 4 nodes and first order shape function Explicit coupling conditionally stable. Small heat capacity and large thermal conductance requires small time steps for the stability of the coupling Example: HEATER : Δz=20 mm THEA : Δz=0.3mm-100mm Temperature in the SC tstep=[10-6 10-3] s tstep=[10-7 10-4] s Joule heating Heat flow from/to the insulation 5 Modelling: Network model vs Hybrid model 11T Cable, B = 11.3 T, I = 11850 A Quenched initiated in the middle turn of a stack of three cable Network Model Hybrid Model Tmax @ t=30 ms [K] 66 68 3% Turn2Turn propagation (ms) 4 3 25 % Longitudinal quench propagation velocity (m/s) 23 22 4% Turn where quench starts Adjacent Turn 70 70 Network Hybrid 60 60 50 50 40 40 2 1 0 0 Preliminary results 5 10 15 t [ms] 20 25 30 T [K] 3 T [K] Quenched Length [m] Network Hybrid Network FE mesh 5 4 Diff 30 30 20 20 10 10 Preliminary results 0 5 10 15 20 t [ms] 25 Preliminary results 30 0 5 10 15 20 t [ms] Negligible impact of the thermal coupling method on the longitudinal quench propagation 25 6 30 Validation of the model Available experimental data SMC 11T (H. Bajas): Pole turn @ 1.9 K I=12936 A (Bp=11.3 T) v= 27 m/s SMC3 (H. Bajas): Pole turn @ 1.9 K & 4.4 K, I ≈ 11.5-14.2kA HQ01d (M. Marchevsky) Training quenches. I = 14.3 kA I = 13.6 kA MBHSP01(G. Chlachidze): Inner layer pole turn @ 4.5 K I =73% v ~27 m/s MBHSM01 (G. Chlachidze): Outer layer mid-plane turn @ 4.5 K I ≈ 5-12kA v=11.4 m/s v=9.4 m/s 7 Measured propagation velocity [m/s] Experimental data 30 𝑣𝑎𝑑 25 𝐽𝑜𝑝 𝜌𝑘 𝑎𝑣 = 𝛾𝐶 𝑎𝑣 𝑇𝑗𝑜𝑢𝑙𝑒 − 𝑇𝑜𝑝 𝑣𝑎𝑑~ 20 𝐽𝑜𝑝 𝑇𝑗𝑜𝑢𝑙𝑒 − 𝑇𝑜𝑝 SMC3 (1.9K) SMC3 (4.4K) MBHSM01 (4.5K) MBHSP01 (4.5K) HQ01d (4.4K) SMC11T (1.9 K) HQ02b (4.4K) 1/2 1/2 15 10 5 0 100 150 200 250 300 350 Jop/(Tjoule-Top)1/2 [A/mm2/K0.5] 4 6 x 10 5 Cp [J/Km3] Don’t forget that the material properties strongly depend on the temperature and field, and change by several order of magnitudes! 400 Cu Nb3Sn 4 3 2 1 𝜌= 𝜌 𝑇, 𝐵, 𝑅𝑅𝑅 𝑘= 𝑘 𝑇, 𝐵, 𝑅𝑅𝑅 𝐶𝑝 = 𝐶𝑝(𝑇, 𝑇𝑐, 𝐵) 0 0 5 10 T [K] 8 15 Comparison to SMC measured data Conductor + insulation Conductor only Measured longitudinal propagation velocities in SMC11T and SMC3 are close to numerical data when considering the heat capacity of insulation + conductor. 50.0 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 SMC3 4.2 K Conductor + Insulation Only conductor Experimental data v (m/s) v (m/s) SMC3 1.9 K 8 9 10 11 12 I [kA] 13 14 15 50.0 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 Conductor + Insulation Only conductor Experimental data 8 9 10 11 12 13 14 15 I [kA] Experimental data H. Bajas Remark: natural quenches in the high field region 9 Comparison to 11T measured data Spot heater test in the outer layer mid-plane turn I [kA] 5 7 9 12 Bpeak, OL mid-plane [T] 2.65 3.44 4.25 5.50 MBHSM01 4.2 K The 11T mirror magnet tested at FNAL shows velocities ~2.5 times larger than the ones predicted by the model v (m/s) 25.0 Only conductor 20.0 Conductor + Insulation 15.0 Experimental data 10.0 5.0 0.0 5 7 I [kA] 9 11 Experimental data G. Chlachidze 10 Expected long. propagation QXF I (kA) 12 14 16 18 20 Bp [T] Bp [T] (HF: Pole turn IL) (LF: Mid plane turn OL) 8.5 9.8 11.1 12.4 13.7 3.4 4.1 4.9 5.7 6.5 Field @ I=Inom=17.5kA 100 HF (only conductor) HF (Conductor + Insulation) LF (Only Conductor) v (m/s) LF (Conductor+Insulation) 10 T = 1.9 K 1 12 13 14 15 16 I (kA) 17 18 Inom 19 20 11 REFERENCES • MATERIAL PROPERTIES • • • • [Man 2011] G. Manfreda, Review of ROXIE's Material Properties Database for Quench Simulation [TD Note ----] TD Note 00-041, Material properties for quench simulation [Dav ----] A. Davies, Material properties data for heat transfer modelling in Nb3Sn magnets EXPERIMENTAL DATA • • [Mar 2012] M. Marchevsky. Quench Performance of HQ01, a 120 mm Bore LARP Quadrupole for the LHC Upgrade MODELLING • • • • • • • • [Bot 2004] Power. User’s Guide. CryoSoft, Ver. 2.0; 2004 [Bot 2007] SuperMagnet. User’s Guide. CryoSoft, Ver. 1.0; 2007 [Bot 2010] Thea. User’s Guide. Cryosoft, Ver. 2.1; 2010 [Bot 2010] Heater. User’s Guide. Cryosoft, Ver. 2.0; 2010 [Bot 2013] L. Bottura, Magnet Quench 101, WAMSDO CERN 2013 [Gav 1992] A. Gavrilin, Cryogenics, 32 (1992), 390-393 [Rus 2008] S. Russenschuck. Field Computation for Accelerator Magnets [Sch 2010] Numerical Calculation of Transient Field Effects in Quenching Superconducting Magnets. PhD Thesis 12 Cable Data DATA BEFORE REACTION # strands Strand diameter Cu/nCu Cable width Bare Cable Mid-Thickness mm mm mm 14 1.25 1.25 9.9 2.2 SMC3 40 0.7 1.25 14.99 1.305 SMC 11T 11T 40 0.7 1.15 14.7 1.25 HQ 35 0.778 1.13 15.15 1.437 QXF 40 0.85 1.13 18.15 1.525 Insulation thickness mm 0.1 0.15 0.15 0.1 0.15 14 Modelling: length scale 2 Principal directions: longitudinal and transverse Longitudinal length scale: hundreds of m Cable is a continuum “relatively easy” to solve with accurate (high order) and adaptive (front tracking) methods Transverse length scale: mm Heat diffusion across the insulation 15 Modelling: time scale • Heat flow • • • • Heat flow from supports and structures Heat flow in the coil winding Heat flow along the cable 1s 1s 100 µs Electro-magnetics • • • • Steady and transient coil currents Steady and transient magnetics fields Current distribution in the cable Steady and transient magnetization 1s 1s 1 ms 10 µs 16 Conductor only Conductor /insulation Conductor +insulation 17 Network FE mesh 18 Network vs Mesh. Joule heating 3.5 4 x 10 Turn where quench starts 3 4 3 x 10 Adjacent Turn Network Hybrid Network FE mesh 2.5 2.5 2 QJ [W/m] QJ [W/m] 2 1.5 1.5 1 1 0.5 0.5 0 0 10 20 t [ms] 30 0 0 10 20 30 t [ms] 19 Material Properties Cu -7 -8 -9 10 CUDI&Hugo MATPRO NIST&Ezio&Cryosoft Heat Capacity [J/K*m3] Electrical Resisitivity [ohm*m] 10 10 -10 10 Cu 8 10 0 6 10 CUDI MATPRO NIST Ezio Hugo Cryocomp 4 10 2 100 200 10 300 0 100 T [K] Nb3Sn 8 Heat Capacity [J/K*m3] Heat Capacity [J/K*m3] 10 6 10 4 10 CUDI MATPRO Ezio Hugo Cryocomp 2 10 0 0 300 G10 8 10 10 200 T [K] 6 10 4 10 NIST&Hugo Ezio Cryocomp Fermilab 2 10 0 100 200 T [K] 300 10 0 100 200 300 T [K] 20 Material Properties Cu 10 10 CUDI&Hugo MATPRO NIST&Ezio&Cryosoft -8 10 -9 10 -10 10 Cu 8 Heat Capacity [J/K*m3] Electrical Resisitivity [ohm*m] -7 CUDI MATPRO NIST Ezio Hugo Cryocomp 6 10 4 10 2 0 10 1 2 10 10 10 0 10 3 10 1 T [K] 10 Heat Capacity [J/K*m3] Heat Capacity [J/K*m3] 3 10 G10 8 10 6 10 4 CUDI MATPRO Ezio Hugo Cryocomp 10 2 10 0 10 0 10 10 T [K] Nb3Sn 8 2 10 6 10 4 10 NIST&Hugo Ezio Cryocomp Fermilab 2 10 0 1 2 10 10 T [K] 3 10 10 0 10 1 2 10 10 3 10 T [K] 21 Sensibility to material properties SMC 11T, B= 12T , RRR=100 Electrical Resistivity Copper Electrical CUDI (1) Resistivity Copper MATPRO (2) (1) CUDI NIST (3) MATPRO (2) NIST (3) CASE [resCu, CpCu,CpNb3Sn,CpG10] CASE 1113 [resCu, CpCu,CpNb3Sn,CpG10] 2113 1113 3113 2113 1213 3113 1313 1213 1413 1313 1513 1413 1613 1513 1123 1613 1143 1123 1153 1143 1163 1153 1114 1163 1116 1114 1117 1116 1553 1117 3666 1553 3444 3666 3323 3444 3323 Cu CUDI (1) Cu MATPRO (2) (1) CUDI NIST (3) MATPRO Ezio (4) (2) NIST Hugo(3) (5) (4) Ezio CRYOCOMP (6) Hugo (5) CRYOCOMP (6) MIITs for Tmax=300K MIITs 13.74 for Tmax=300K 14.27 13.74 15.07 14.27 13.74 15.07 13.74 13.74 13.76 13.74 14.25 13.76 13.65 14.25 15 13.65 15.12 15 14.4 15.12 14.99 14.4 13.67 14.99 14.13 13.67 14.25 14.13 14.90 14.25 16.78 14.90 16.53 16.78 16.45 16.53 16.45 Heat capacity Nb3Sn capacity Heat(1) CUDI Nb3Sn MATPRO(2) CUDI (1) MATPRO(2) Ezio (4) Hugo (5) (4) Ezio CRYOCOMP (6) Hugo (5) CRYOCOMP (6) G10 G10 NIST (3) Ezio (4) NIST (3) (4) Ezio CRYOCOMP (6) FERMILAB(7) CRYOCOMP (6) FERMILAB(7) ? delta MIITs delta MIITs [%] Comments delta MIITs 0.53 1.33 0.53 0 1.33 0 0 0.02 0 0.51 0.02 -0.09 0.51 1.26 -0.09 1.38 1.26 0.66 1.38 1.25 0.66 -0.07 1.25 0.39 -0.07 0.51 0.39 1.16 0.51 3.04 1.16 2.79 3.04 2.71 2.79 2.71 delta MIITs [%] 3.86 9.68 3.86 0.00 9.68 0.00 0.00 0.15 0.00 3.71 0.15 -0.66 3.71 9.17 -0.66 10.04 9.17 4.80 10.04 9.10 4.80 -0.51 9.10 2.84 -0.51 3.71 2.84 8.44 3.71 22.11 8.44 20.33 22.11 19.73 20.33 19.73 Comments (HugoMP) (Cryocomp MP) (HugoMP) (Ezio MP) (Cryocomp (Susana MP)MP) (Ezio MP) (Susana MP) For SMC-11T cable, MIITs to reach 300 K under adiabatic conditions vary from 14 to 17.5 depending on the material properties database 22 Material Properties Cryosoft [1.9-15 K] -10 4 6 5 4 Thermal Conductivity Cu [W/Km] RRR=50, B=2 RRR=100, B=2 RRR=50, B=12 RRR=100, B=12 Electrical Resisitivity Cu [ m] 1400 1200 RRR=50, B=2 RRR=100, B=2 RRR=50, B=12 800 RRR=100, B=12 1000 600 400 1400 1200 1000 800 600 T [K] 2 15 0 0 0 5 x 10 Cu Nb3Sn 5 4 4 3 3 2 2 1 1 400 200 10 6 CuB=2 RRR=50, Nb3Sn RRR=100, B=2 5RRR=50, B=12 RRR=100, B=12 1600 3 5 6 Cp [J/Km3] 7 RRR=50, B=2 RRR=100, B=2 RRR=50, B=12 RRR=100, B=12 Thermal Conductivity Cu [W/Km] 1600 1800 4 x 10 Cp [J/Km3] x 10 8 1800 200 5 10 T [K] T [K] 10 15 0 15 0 0 0 5 5 10 T [K] T [K] 10 15 0 15 0 5 10 T [K] 23 ROXIE Quench Module Thermal network: Heat capacity: includes conductor + insulation Thermal conductance and heat fluxes: Conductor without insulation. Uniform temperature in the conductor and linear temperature distribution in between them 24 Current sharing and Joule heating I st = I op - I c Iop current in stabilizer I sc = I c Top ì0 ïï T - Tcs q¢J¢¢ = íq¢J¢¢max Tc - Top ï ïîq¢J¢¢max Tcs Tc for T < Tcs for Tcs < T < Tc for T > Tc current in superconductor T q¢J¢¢max q¢J¢¢max = Top 2 hst I op Ast A Tcs Tc 25 T Higher order thermal coupling for MBHSM01 (Supermagnet) Quench pole turn IL (longitudinal propagation) T conductor [K] 300 250 Experimental points OL mid plane 200 IL mid plane 3. Quench OL pole turn (t=29 ms) IL pole 150 OL pole 100 Quench IL HF (transversal) OL mid plane 50 0 0.000 0.050 0.100 time (s) 0.150 0.200 4. OL fully quenched Quench IL LF (transversal) 1. Spot heater provoked quench Looking at the delays … • The first conductor that quenches thanks to the quench heaters, quench at the measured delay: 29 ms (heater delay defined accordingly to satisfy this) • All the OL quenches within ≈ 7 ms • Quench travels very fast from OL to IL thanks to the longitudinal propagation (≈ 2 ms) • IL-OL delay due to transversal propagation is ≈ 20 ms in the HF (Bp=9.5T) and about ≈25 ms in the LF (Bp=8.5T) 26 MBHSM01. Spot heater test I = 12 kA MIITs T MEASURED TMAX ANALYTIC (B=5.5 RRR=100) TMAX FIRST ORDER THERMAL COUPING (ROXIE) TMAX HIGHER ORDER THERMAL COUPING (SUPERMAGNET) 8 92 82 88 74 10 118 105 117 99 12 142 136 156 134 14 180 175 205 185 250 Tmax [K] 200 T MEASURED T analytic T ROXIE T SuperMagnet 150 100 50 8 9 10 11 MIITs 12 13 14 27