ARIES-AT Blanket and Divertor Design (The Final Stretch) The ARIES Team Presented by A. René Raffray and Xueren Wang ARIES Project Meeting University of Wisconsin, Madison June 19-21, 2000
Presentation Outline Blanket Geometry and coolant routing Update analysis and parameters based on 3/10/00 strawman New analysis 2-D moving coordinate thermal analysis Pressure stress in inner SiC/SiC separation wall Manifolding Thermo-fluid analysis Divertor Configuration with LiPb as coolant Thermal and stress analysis Fabrication Summary
ARIES-AT Machine and Power Parameters from 3/10/00 Strawman Power and Neutronics Parameters Fusion Power 1719 MW Neutron Power 1375 MW Alpha Power 344 MW Current Drive Power 25 MW Transport Power to Divertor 256 MW Fraction of Divertor Power Radiated Back to FW TBD Overall Energy Multiplication 1.1 Total Thermal Power 1897 MW Average FW Surface Heat Flux 0.26 MW/m 2 Max. FW Surface Heat Flux 0.34 MW/m 2 Max. Divertor Surf. Heat Flux 5 MW/m 2 Average Wall Load 3.2 MW/m 2 Maximum O/B Wall Load 4.8 MW/m 2 Maximum I/B Wall Load 3.1 MW/m 2 Machine Geometry Major Radius 5.2 m Minor Radius 1.3 m FW Location at O/B Midplane 6.5 m FW Location at Lower O/B 4.9 I/B FW Location 3.9 m Toroidal Magnetic Field On-axis Magnetic Field 5.9 T Magnetic Field at I/B FW 7.9 T Magnetic Field at O/B FW 4.7 T
SiC/SiC Properties Used for Design Analysis (Consistent with SiC/SiC Town Meeting Suggestion) Density ~3200 kg/m 3 Density Factor 0.95 Young's Modulus ~200-300 GPa Poisson's ratio 0.16-0.18 Thermal Expansion Coefficient 4 ppm/ C Thermal Conductivity in Plane ~20 W/m-K Therm. Conductivity through Thickness ~20 W/m-K Maximum Allowable Combined Stress ~190 MPa Maximum Allowable Operating Temperature ~1000 C Max. Allowable SiC/LiPb Interface Temperature ~1000 C Maximum Allowable SiC Burnup ~ 3%
Cross-Section and Plan View of ARIES-AT Showing Power Core Components
Cross-Section and Plan View of ARIES-AT Showing Maintenance Approach All Lifetime Components Except for: Divertor, IB Blanket, and OB Blanket I
Coolant Routing Through 5 Circuits Serviced by Annular Ring Header (I) LiPb Coolant Inlet Temperature 653 C Outlet Temperature 1100 C Blanket Inlet Pressure 1 MPa Divertor Inlet Pressure 1.7 MPa Mass Flow Rate 22,700 kg/s Circuit 1: Lower Divertor + IB Blanket Circuit 1 - Lower Divertor + IB Blkt Region Thermal Power and Mass Flow Rate: 501 MW and 6100 kg/s Circuit 2 - Upper Divertor + 1/2 OB Blanket I 598 MW and 7270 kg/s Circuit 3-1/2 OB Blanket I 450 MW and 5470 kg/s Circuit 4 - IB Hot Shield + 1/2 OB Blanket II 182 MW and 4270 kg/s Circuit 5 - OB Hot Shield + 1/2 OB Blanket II 140 MW and 1700 kg/s
Coolant Routing Through 5 Circuits Serviced by Annular Ring Header (II) Circuit 2: Upper Divertor + 1/2 OB Blanket I Circuit 3: 1/2 OB Blanket II
Coolant Routing Through 5 Circuits Serviced by Annular Ring Header (III) Circuit 4: IB Hot Shield + 1/2 OB Blanket II Circuit 5: OB Hot Shield + 1/2 OB Blanket II
ARIES-AT Outboard Blanket Segment Configuration and Coolant Manifold
Cross-Section of ARIES-AT Outboard Blanket
LiPb Temperature Distribution in FW Channel and Inner Channel under MHD-Laminarization T w FW Exit (Upper Outboard) FW Channel v back T LiPb,min T in T LiPb,avg LiPb q'' plasma Poloidal q'' back Inner Channel T w TLiPb,min T in FW Midplane T LiPb,avg q''' LiPb Radial v FW FW Inlet (Lower Outboard) T in SiC/SiC FW T in T out SiC/SiC Inner Wall
Poloidal Distribution of Surface Heat Flux and Neutron Wall Load from 3/10/00 Strawman Plasma Surface Heat Flux (MW/m2) 0.60 0.50 0.40 0.30 0.20 0.10 Assuming 10% divertor transport power re-radiation Assuming no radiation from divertor OUTBOARD DIV. INBOARD Neutron Wall Load (MW/m2) 5.50 5.00 4.50 4.00 3.50 3.00 2.50 2.00 1.50 Average Neutron Wall Load = 3.19 MW/m2 DIV. OUTBOARD INBOARD 0.00 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Poloidal Distance from Lower Outboard (m) 1.00 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Poloidal Distance from Lower Outboard (m)
Temperature Distribution in ARIES-AT Blanket Based on 2-D Moving Coordinate Analysis 1200 1100 1000 900 800 0.1 1 2 Poloidal 3 distance (m) 4 5 6 0.08 0.1 0.06 0.08 0.04 0.02 0 0.06 0.04 0.02 Radial distance (m) 0 1200 1100 Temperature ( C) 1000 900 800 700 SiC/SiC LiPb 1200 1100 1000 900 800 700 LiPb Inlet Temperature = 764 C From Plasma Side: - CVD SiC Thickness = 1 mm - SiC/SiC Thickness = 4 mm (SiC k = 20 W/m-K) - LiPb Channel Thickness = 4 mm - SiC/SiC Separ. Wall Thickness = 5 mm ( SiC k = 6 W/m-K) LiPb Velocity in FW Channel= 4.2 m/s LiPb Velocity in Inner Channel = 0.1 m/s Poloidal neutron wall load and plasma heat flux profiles used as input (assuming no radiation from divertor)
2-D Moving Coordinate Analysis of FW and Inner Channel Poloidal neutron wall load and plasma heat flux profiles used as input (assuming no radiation from divertor) FW Maximum CVD and SiC/SiC Temperature = 1009 C and 996 C Maximum SiC/LiPb Interface Temperature at Inner Wall = 994 C (occurs at higher y poloidal as k SiC increases) FW CVD SiC Armor FW SiC/SiC FW LibP Inner SiC Temp. ( C) 1100 1050 1000 Lower Poloidal Location Max. CVD SiC Temp. Max. SiC/SiC Temp. Temp. ( C) 1150 1100 1050 1000 Inner LiPb Channel Midplane Lower Poloidal Location 950 900 850 Design Point Max. SiC/LiPb Interface Temp. Upper Poloidal Location ARIES-AT Outboard Blanket Module Series Flow: FW Channel and Inner Channel FW SiC/SiC Thickness = 5 mm FW Channel Thickness = 4 mm SiC/SiC Inner Wall Thickness = 5 mm Inner Channel Effective Thickness = 9 cm SiC/SiC First Wall k = 20 W/m-K LiPb Inlet Temperature = 764 C 800 0 2 4 6 8 10 12 14 16 18 20 22 Inner Wall SiC/SiC Thermal Conductivity (W/m-K) 950 900 850 800 750 700 Upper Poloidal Location ARIES-AT Outboard Blanket Module Series Flow: FW Channel and Inner Channel FW SiC/SiC Thickness = 5 mm FW Channel Thickness = 4 mm SiC/SiC Inner Wall Thickness = 5 mm Inner Channel Effective Thickness = 9 cm SiC/SiC First Wall k = 20 W/m-K SiC/SiC Inner Wall k = 6 W/m-K LiPb Inlet Temperature = 764 C 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 Radial Thickness from FW Surface (m)
Pressure Stress Analysis of Inner Shell of Blanket Module Differential Pressure Stress on Blanket Module Inner Shell Varies Poloidally from ~ 0.25 MPa at the Bottom to ~ 0 MPa at the Top Maximum Pressure Stress for 0.25 MPa Case 218 MPa for 5-mm thickness 116 MPa for 8-mm thickness Use 7 mm as reference case to comfortably maintain combined stress limit < 190 MPa Thickness Varies from7 mm at Bottom to ~ 3 mm at Top
LiPb Inlet Manifolding Analysis q'' LiPb Outlet Annular manifold configuration with low temperature inlet LiPb in outer channel and high temperature outlet LiPb in inner channel r i r o Can the manifold be designed to maintain LiPb/SiC T interface < LiPb T outlet while maintaining reasonable P? Use manifold between ring header and outboard blanket I as example
LiPb/SiC T interface, LiPb T Bulk due to Heat Transfer in SiC/SiC Annular Piping, and P as a Function of Inner Channel Radius Reduction in T interface at the expense of additional heat transfer from outlet LiPb to inlet LiPb and increase in LiPb T inlet Very difficult to achieve maximum LiPb/SiC T interface < LiPb T outlet However, manifold flow in region with very low or no radiation Set manifold annular dimensions to miminimize T bulk while maintaining a reasonable P Temp. ( C) 1200.0 1100.0 1000.0 900.0 800.0 700.0 600.0 500.0 400.0 300.0 200.0 100.0 0.0 Max. LiPb/SiC T int Circuit 2: Series Flow through Upper Divertor and One O/B Blanket Region 1 Segment One of 16 Annular Pipes LiPb Mass Flow Rate in Annular Piping = 45.4 kg/s Piping Length = 8 m Outer Radius, r o, = 0.12 m SiC/SiC Outer and Inner Wall Thickness = 5 mm LiPb Inlet Temperature = 653 C LiPb Outlet Temperature = 1100 C LiPb T bulk due to q'' k SiC (W/m-K) 0 0.025 0.05 0.075 0.1 Annular Piping Inner Channel Radius, r i (m) 1 10 10 1 P (MPa) 1 0.1 0.01 0.001 LiPb Inlet LiPb Outlet r i r o 0 0.025 0.05 0.075 0.1 q'' Annular Piping Inner Channel Radius, r i (m)
Divertor Design Preferred Option: LiPb Cooled Configuration Single power core cooling system Low pressure and pumping power Analysis indicates that proposed configuration can accommodate a maximum heat flux of ~5-6 MW/m 2 Alternate Options: He-Cooled Porous Exchanger Higher pressure, pressure drop and pumping power Challenging heat transfer performance if He from power cycle at ~600 C inlet temperature Liquid Wall (Sn-Li)
ARIES-AT Divertor Configuration and LiPb Cooling Scheme Accommodating MHD Effects: Minimize Interaction Parameter (<1) (Strong Inertial Effects) Flow in High Heat Flux Region Parallel to Magnetic Field (Toroidal) Minimize Flow Length and Residence Time Heat Transfer Analysis Based on MHD-Laminarized Flow LiPb Poloidal Flow in ARIES-AT Divertor Header Example schematic illustration of 2-toroidal-pass scheme for divertor PFC cooling Poloidal Direction Plasma q'' A A Cross-Section A-A Toroidal Direction
Temperature Distribution in Outer Divertor PFC Channel Assuming MHD-Laminarized LiPb Flow 0.001 0.002 0.003 0.004 0.005 0 1200 1200 B T PFC 1100 1000 900 800 700 600 0 0.005 0.01 Toroidal distance (m) 0.015 1100 Temperature ( C) 1000 900 800 700 0.001 0.002 0.003 0.004 Radial distance (m) 0.005 0.006 Tungsten 0.02 SiC/SiC LiPb 1100 1000 900 800 700 600 LiPb LiPb 2-D Moving Coordinate Analysis Inlet temperature = 653 C W thickness = 3 mm SiC/SiC Thickness = 0.5 mm LiPb Channel Thickness = 2 mm SiC/SiC Inner Wall Thick. = 0.5 mm LiPb Velocity = 0.35 m/s Surface Heat Flux = 5 MW/m 2
Thermal Analysis of Divertor Channel Maximum SiC/SiC Temperature ~ 950 C Maximum SiC/SiC Thermal Stress ~ 160 MPa
Pressure Stress and Pressure Drop in Divertor Channel B T PFC LiPb LiPb 2-cm toroidal dimension and 2.5 mm min. W thickness selected (+ 1mm sacrificial layer) - SiC/SiC pressure stress ~ 35 MPa for a combined stress of ~195 MPa - P is minimized to ~0.55 MPa for lower divertor and ~0.7 MPa for upper divertor Maximum SiC/SiC Temperature ~ 950 C Pressure Drop (MPa) 2.00 1.50 1.00 0.50 Inner Channel Orifice PFC Channel Total 0.00 0 0.01 0.02 0.03 0.04 0.05 Toroidal Dimension of Divertor Channel (m)
Outer Divertor Plate with Brazed Coolant Manifold Minimize brazing SiC/SiC plate manufactured in two toroidal halves with constant dimension channels Flow insert slided in Two halves brazed together End cap + manifold brazed on each end W layer bonded to SiC/SiC (possibly by plasma spray, to be checked by M. Billone)
Typical Blanket and Divertor Parameters for Design Point Blanket Outboard Region 1 No. of Segments 32 No. of Modules per Segment 6 Module Poloidal Dimension 6.8 m Avg. Module Toroidal Dimen. 0.19 m FW SiC/SiC Thickness 4 mm FW CVD SiC Thickness 1 mm FW Annular Channel Thickness 4 mm Avg. LiPb Velocity in FW 4.2 m/s FW Channel Re 3.9 x 10 5 FW Channel Transverse Ha 4340 MHD Turbulent Transition Re 2.2 x 10 6 FW MHD Pressure Drop 0.19 MPa Maximum SiC/SiC Temp. 996 C Maximum CVD SiC Temp. ( C) 1009 C Max. LiPb/SiC Interface Temp. 994 C Avg. LiPb Vel. in Inner Channel 0.11 m/s Divertor Poloidal Dimension (Outer/Inner) 1.5/1.0 m Divertor Channel Toroidal Pitch 2.1 cm Divertor Channel Radial Dimension 3.2 cm No. of Divertor Channels (Outer/Inner) 1316/1167 SiC/Si Plasma-Side Thickness 0.5 mm W Thickness 3.5 mm PFC Channel Thickness 2 mm Number of Toroidal Passes 2 Outer Div. PFC Channel V (Lower/Upper) 0.35/0.42 m/s LiPb Inlet Temperature (Outer/Inner) 653/719 C Pressure Drop (Lower/Upper) 0.55/0.7 MPa Max. SiC/SiC Temp. (Lower/Upper) 970/950 C Maximum W Temp. (Lower/Upper) 1145/1125 C W Pressure + Thermal Stress ~35+50 MPa SiC/SiC Pressure + Thermal Stress ~35+160 MPa Toroidal Dimension of Inlet and Outlet Slot 1 mm Vel. in Inlet & Outlet Slot to PFC Channel 0.9-1.8 m/s Interaction Parameter in Inlet/Outlet Slot 0.46-0.73
Extra Margin on Accommodating Temperature Limit by Reducing Coolant Temperature with Relatively Small Impact on Brayton Cycle 1200 1100 Temp. ( C) 1000 900 800 700 600 500 Blanket LiPb Outlet Temp. Cycle He Max. Temp. (at HX Outlet ) Cycle He Temp. at HX Outlet 0.54 0.55 0.56 0.57 0.58 0.59 0.6 Cycle Efficiency Cycle He Temp. at HX Inlet Brayton Cycle Parameters: - Min. He Temp. in cycle (heat sink) = 35 C - 3-stage compression with 2 inter-coolers - Turbine efficiency = 0.93 - Compressor eficiency = 0.88 - Recuperator effectiveness = 0.96 - Cycle He fractional P = 0.03 - Total Compression ratio = 3 Heat Exchanger: - Effectiveness = 0.9 - (mcp) He /(mcp) LiPb = 1
Future Work Includes: Complete 3-D structural analysis of divertor Surface heat flux profile required (GA) Evolve in more detail blanket and divertor fabrication flow diagrams Documentation