MINI-CHANNELS COOLING FOR HIGH HEAT FLUX MANAGEMENT

Transcription

1 MINI-CHANNELS COOLING FOR HIGH HEAT FLUX MANAGEMENT Numerical and Experimental studies for the Fingers in the S 3 Beam Dump Project (S 3 : Super Separator Spectrometer) NADIA SELLAMI SIS On behalf of the S 3- BD Team (SIS/SPhN/SACM)

2 OUTLINE OF THE PRESENTATION: Integration of mini-channels cooling Technology For the S 3 -BD Project: Framework and Specifications for the Fingers Within the S 3 -BD Project: Numerical Studies: concept validation & optimization of solutions Experimental Campaigns: Fabrication challenges and structural testing Final Design & Exploitation: potential optimization Beyond the S 3 -BD Project: Collaboration and Funding Opportunities 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 2

3 GLOBAL VIEW OF THE S3 EXPERIMENT IN GANIL For S3-BD Selective Beam Dump Area: 99.9% of the beam stopped Bunker Primary beam extraction Stopping the beam power Activation confinement 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 3

4 SCHEMATIC VIEW OF THE PRIMARY SELECTIVE LINE 2 beam dump zones with fixed and movable elements: Upstream: one fixed plate + two movable shutters Downstream(around the focal plane): one fixed plate+ two movable shutters + five movable fingers Upstream BD Fixed Plate + 2 shutters Downstream BD For S3-BD Upstream BD Beam Downstream BD Focal plane Fixed Plate + 2 shutters + 5 fingers Open triplet Multipoles + Delta Chamber + 2 Beam Dump Areas Design of the fingers submitted to various constraints and specification: Size limitation: depth ~ 30mm and width ~ 10mm Stopping localized high heat loads: ~ 1kW/cm 2 Robustness: ~10years (activation, cyclic thermal strains, pressure, corrosion ) Scattering minimization 08-Jan-2014 Integration of minichannels cooling technology in the S 3 -BD project 4

5 Beam Simplified Solid Geometry Liquid Volume Counterpart DESIGN CHOICES FOR THE FINGERS: CHALLENGES Beam The finger: A V-shaped thin structure in Cu with a W coating of ~1mm thickness: flux/16 + limited scattering Mini-channel Cooling Technology (~1-2mm diameter): 7 channels distributed on both sides of the V-shape High heat loads: thin walls within the element (manufacturing a prototype) yet various solicitations: high flow rates, pressure, corrosion (deionized water), activation, fatigue => prevent CHF Outlet water For S3-BD Mini-channels Inlet water cross section Axed Configuration De-Axed Configuration 10mm x 30mm x 100mm 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 5

6 OBJECTIVES: Design Qualification & Validation The capability of the finger to stop high density flux beams (up 1kw/cm 2 and beyond). Determination of the nominal operating conditions and the tolerances for the final experiments (long-term exposure, mechanical integrity, safety requirements). The cooling technology. The numerical modeling: consolidate the simulations procedures and introduce new tools Development: Optimization of the design: geometry, mini-channels distribution and position, angles Numerical tools to explore higher beam density fluxes Exploration: Gain insight on the cooling mechanisms and tapping in the CHF regimes Investigate more cooling technologies 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 6

7 Température (C) S 3 BEAM DUMP : MOCKUP ASSEMBLY Conception, Industrial follow-up and Integration/Instrumentation : SIS (LEIGE + LCAP+LRI) Exploitation and Analysis: SIS (LEIGE, LCAP &LDISC) +SACM +SPhN Profil Température le long du Peigne Central Sondes de 1kW SILHI@IPHI Finger + SILHI beam Beam profile reconstruction Control-monitoring by EPICS µ-vis CT Imaging Centre Structural assessment and analysis Metallography

8 THERMO-HYDRAULIC SIMULATIONS: CHALLENGES Q q A h ave h ave f A( T ( w T Re, Pr) ) h ave A T Liquid: Solving Navier-Stokes equations (+ Energy equation) Solid: Solving Fourier s equation (Energy Equation) 2 Approaches for the validation: Forced convection => Turbulence Modeling (RANS) Bounded flows => Wall Modeling Heat transfer => Heat exchange coefficient Modeling or/and Conjugate heat Transfer Cautious of the Heat Crisis => Quality of the Mesh at the wall - Chained Calculations: - Conjugate Heat transfer calculations: Uniform, constant conditions Single vs. two phase flows Use empirical formalism to estimate Nucleation problems the heat exchange coefficient CFD Calculation: Length of establishment of the full regime Cavitation problem 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 8

9 SOFTWARE: SOLVERS AND PRE/POSTPROCESSING Post and Pre-processing Solvers 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 9

10 CFD CALCULATION: OPENFOAM (CASE 12L/MIN / K-Ε MODEL / WALL FUNCTION) In the Middle Section: Max U channel = 5,52 m/s Min U channel = 3,95m/s Pressure drop ΔP = 0,45bar => #U between channels = 28% Length of regime Inlet ~ 30mm Vitesse le long du canal 6 ((m/s) Vitesse le long du canal 2 ((m/s) 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 10

11 CFD CALCULATION: OPENFOAM (CAS 12L/MIN / K-Ω SST MODEL / NO WALL FUNCTION) Velocity Profile (m/s) pour canal 6 In Middle Section: Max U channel = 5,11 m/s Pressure drop ΔP = 0.51bar 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 11

12 OPTIMIZATION: HYDRAULIC CONFIGURATIONS 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 12

13 COUPLED SIMULATIONS: CFX VS. SATURNE-SYRTHES ANSYS-CFX SATURNE/SYRTHES Temperature Profile along the first water channel Central Section Downstream Section Flow Rate: 12L/min Temperature along the Cu 25 C 31 C 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 13

14 Temperature (C) EXPERIMENTAL RESULTS ANALYSIS Flow rates: 15L/min -> 25L/min Total power deposited: 500W ->3000W Direction: y+/y- Time of interaction Gaussian profiles Static Pressure in mid-section: ,95 2,75-4 bar ( C) 2000W Observations W Effet de débit Use similar Gaussian same position Data treated for the same reference temperature Max Temperature (raw data) = 99 C (@ 15L/min) Dissymmetric temperature profiles on both sides for the V-shape Data showed with respect to various flow rates (check pressure drop if phase change) If Nucleate Boiling: the maximum power possible is reached HAUT-24.5L/min BAS-24.5L/min HAUT-30L/min BAS_30L/min HAUT_19.5L/min Beam profile reconstruction Pos. Peigne central Jan-2014 Integration of minichannels cooling technology in the S3-BD project 14

15 Delta P (bar) Debit moyen d'eau (L/min) Perte de Charge ( bar) EXPERIMENTAL RESULTS ANALYSIS: avec Faisceau Mesures Initiales Doigt monté-sans pression statique Doigt monté-avec pression statique = 4bar inlet 2.5 inlet y = x x R² = inlet 1 Débit (L/min) Valeurs Expérimentles 3.5 OpenFoam-k-epsilon 3 OpenFoam-Spalart-Allmaras OpenFoam komegasst 2.5 OpenFoam Tomographie Géo_Tomo Débit (l/min) Inlet : 4.25m/s - 20L/min Decale 1 Centre Decale 2 Decale_1 25L/min h=30,000 à 35,000 W/K.m 2 h= 36,000 à 42,000 W/K.m Num. Canal 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 15

16 EXPERIMENTAL RESULTS ANALYSIS: NUCLEATE BOILING? 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 16

17 SIMULATION VS. EXPERIMENT: 2000W CASE Developed routines for heat flux projection Heat Flux (W/m 2 ) Temperature ( C) Offset between measurements and simulations: - Probes calibration and measurement - Real geometry - Spatial orientation: beam/finger - Cooling regime - Heat transfer through Cu/W joint - Numerical model Case with a shift between beam center and probes ~ x ~ ~ 08/04/2013 R&D SIS: Calculs Multi-Physique Couplés en Thermo-Hydraulique 17

18 FURTHER ANALYSIS: 1- NDT: CT with μvis Lab with Southampton University De-axed Finger 3- Estimation of the thermal contact resistance through the Cu/W joint by Fahrenheit- Epsilon DOIGT CENTRE 2- Metallographic and chemical treatment of specific cross sections with IS (Institut de Soudure) => Consolidate the simulations tools 08-Jan-2014 Integration of minichannels cooling technology in the S3-BD project 18

19 COLLABORATIONS & FUNDING OPPORTUNITIES Beyond S3-BD Collaborations & Discussion Through similar applications within CEA: IFMIF, Emittance meter (Spiral2), RFQ ESS Identification of similar groups / Labs facing the same high heat flux challenges: IPN Orsay, LNCMI Grenoble, LEGI Grenoble, CEA/IRFM & CNRS/LIMSI. Solicited Funding: Within the Labex P2IO in collaboration with IPN Orsay Through ANR: LEGI «MIcroSurface Structuring in Minichannels for Enhanced Heat Transfer» 08-Jan-2014 Integration of minichannels cooling technology in the S 3 -BD project 19