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Parametric Thermal-Hydraulic Analysis of TBM Primary Helium Loop

Greg SviatoslavskyFusion Technology Institute,

University of Wisconsin, Madison, WI

With contributions from

C.P.C. Wong, General Atomics, M. Dagher, S. Smolentsev, UCLA, S. Malang, Consultant, Germany

ITER US TBM MeetingUCLA

MAY 10, 2006

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Presentation Outline

Primary helium loop description

First Wall thermal analysis

TBM pressure drop

Results summary

Future work & consideration

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He Circuit 1

He Circuit 2

Primary Helium Loop

Back PlateFirst Wall

Top Plate

Bottom Plate

Divider Plate

Grid Plates

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First Wall Analysis ApproachD-T Transient

Thermal Conditions

Helium Inlet & Outlet

Temperature

Parametric Analysis

FW Channel Layout

FW Temperature

LimitsRequire Heat

Transfer Coefficient (h)

Require Helium Flow

Rate

Channel Dimensions & Roughening

Max FW Temperature

FW Pressure

Drop

Parametric Analysis

Parametric Analysis

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• 0.3 MW/m2 flux over 90% & 0.5 MW flux over 10% FW

• Nuclear heating based on scaling prior neutronic results

• 520o C maximum FW temperature at 2 mm depth

• 550o C maximum FW surface temperature

First Wall Analysis Input Parameters

• 300o C helium TBM inlet temperature

• 390o C helium TBM outlet temperature

• 20 mm x 19.6 mm channel cross-section dimensions

• Uniform sand-grain roughness

• Seven pass circuit layout (5 channels per pass)

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• 0.89 kg/s required helium flow rate

• 4813 W/m2-K heat transfer coefficient

• 378o C FW helium exit temperature

• 523o C maximum FW temperature at 2 mm depth

• 556o C maximum FW surface temperature

First Wall Thermal Analysis Results

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Circuit 2 Total P-drop 0.0107

MPa

TBM Pressure Drop ResultsFirst Wall 0.096 MPa

Top Plate 0.001 MPa

Bottom Plate 0.001 MPa

Divider Plate

Grid Plates

First Wall 0.096 MPa

0.003 MPa

0.01 MPa

0.005 MPa

Circuit 1 Total P-drop 0.104

MPa

8 0.000

0.020

0.040

0.060

0.080

0.100

0.120

Pre

ssu

re D

rop

(M

Pa)

• First Wall 0.096 MPa

• Top/Bottom Plate 0.001 MPa

• Divider Plate 0.005 MPa

• Upper Grid Plates 0.003 MPa

• Lower Grid Plates 0.01 MPa

TBM Pressure Drop Results

Fir

st W

all

Top

Pla

te

Bot

tom

Pla

te

Div

ider

Pla

te

Upp

er G

rid

Pla

te

Low

er G

rid

Pla

te

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• Downstream (hotter) FW flow requires higher h than upstream (cooler) flow

• Control velocity with number of channels per pass [h is f(velocity)]

• Initial analysis indicates pressure drop improves by 34%

Alternate FW Channel Configuration

Pass 1 Pass 2 Pass 3

Fixed Flow Rate

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Helium Thermal-Hydraulic Results SummaryOperational Phase D-T Operation

Heat Flux (transient)0.3 MW over 90% &

0.5 MW over 10%

FW Configuration 7 pass, 5 channels/pass

Flow Rate - FW Velocity 0.89 kg/s - 37 m/s

TBM He inlet/outlet Temperature 300oC / 390oC

Wall Roughness Uniform sand-grain (FW)

Pressure Drop 0.107 MPa

Max FW temperature556oC (surface)

526oC (@ 2mm)

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Future Work & ConsiderationFuture Work & Consideration

Evaluate back plate design

Can we do without 2D roughening?

Determine maximum allowable pressure drop

Investigate alternate configurations

CFD analysis required to better account for FW counter flow and TBM flow distribution

Continue iteration with MHD analysis

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Back-up Slides

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Nuclear Heating Values

First Wall 82187 W

Top Plate 5253 W

Bottom Plate 5253 W

Divider Plate 12200 W

Grid Plates 17113 W

Side Walls 35938 W

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Helium Properties    

Density 6.1 kg/m^3

Specific Heat 5200 j/kg-K

Thermal Conductivity 0.253 W/m-k

Viscosity 3.50E-05 kg/m-s