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Towards Attractive Fusion Power Plants. Farrokh Najmabadi University of California San Diego Presented at Korean National Fusion Research Center Daejon, Korea April 20, 2006 Electronic copy: http://aries.ucsd.edu/najmabadi/ ARIES Web Site: http:/aries.ucsd.edu/ARIES. - PowerPoint PPT Presentation

Towards Attractive Fusion Power PlantsFarrokh NajmabadiUniversity of California San Diego

Presented atKorean National Fusion Research CenterDaejon, Korea April 20, 2006

Electronic copy: http://aries.ucsd.edu/najmabadi/ARIES Web Site: http:/aries.ucsd.edu/ARIES

The ARIES Team Has Examined Several Magnetic Fusion Concept as Power Plants in the Past 15 YearsTITAN reversed-field pinch (1988)ARIES-I first-stability tokamak (1990)ARIES-III D-3He-fueled tokamak (1991)ARIES-II and -IV second-stability tokamaks (1992)Pulsar pulsed-plasma tokamak (1993)SPPS stellarator (1994)Starlite study (1995) (goals & technical requirements for power plants & Demo)ARIES-RS reversed-shear tokamak (1996)ARIES-ST spherical torus (1999)Fusion neutron source study (2000)ARIES-AT advanced technology and advanced tokamak (2000)ARIES-IFE assessment of Inertial Fusion chambers, targets, and drivers (2003)ARIES-CS compact stellarator (2006)

Framework:Assessment Based on Attractiveness & FeasibilityPeriodic Input fromEnergy IndustryGoals and RequirementsEvaluation Based on Customer AttributesAttractivenessCharacterizationof Critical IssuesFeasibilityBalanced Assessment ofAttractiveness & FeasibilityNo: RedesignYes

Elements of the Case for Fusion Power Were Developed through Interaction with Representatives of U.S. Electric Utilities and Energy IndustryHave an economically competitive life-cycle cost of electricityGain Public acceptance by having excellent safety and environmental characteristicsNo disturbance of publics day-to-day activities No local or global atmospheric impactNo need for evacuation planNo high-level wasteEase of licensingReliable, available, and stable as an electrical power sourceHave operational reliability and high availabilityClosed, on-site fuel cycleHigh fuel availabilityCapable of partial load operationAvailable in a range of unit sizes

Framework:Assessment Based on Attractiveness & FeasibilityPeriodic Input fromEnergy IndustryGoals and RequirementsEvaluation Based on Customer AttributesAttractivenessCharacterizationof Critical IssuesFeasibilityBalanced Assessment ofAttractiveness & FeasibilityNo: RedesignYes

A dramatic change occurred in 1990: Introduction of Advanced TokamakOur vision of a fusion system in 1980s was a large pulsed device.Non-inductive current drive is inefficient.Some important achievements in 1980s:Experimental demonstration of bootstrap current;Development of ideal MHD codes that agreed with experimental results.Development of steady-state power plant concepts (ARIES-I and SSTR) based on the trade-off of bootstrap current fraction and plasma b (1990)ARIES-I: bN= 2.9, b=2%, Pcd=230 MW

Framework:Assessment Based on Attractiveness & FeasibilityPeriodic Input fromEnergy IndustryGoals and RequirementsEvaluation Based on Customer AttributesAttractivenessCharacterizationof Critical IssuesFeasibilityBalanced Assessment ofAttractiveness & FeasibilityNo: RedesignYes

Directions for ImprovementImprovement saturates at ~5 MW/m2 peak wall loading (for a 1GWe plant).A steady-state, first stability device with Nb3Sn technology has a power density about 1/3 of this goal.

Evolution of ARIES Designs

1st Stability, Nb3Sn Tech.ARIES-IMajor radius (m)8.0b (bN)2% (2.9)Peak field (T)16Avg. Wall Load (MW/m2)1.5Current-driver power (MW)237Recirculating Power Fraction0.29Thermal efficiency0.46Cost of Electricity (c/kWh)10

Reverse Shear Option

High-FieldOptionARIES-I6.752% (3.0)192.52020.280.498.2

ARIES-RS5.55% (4.8)164810.170.467.5

ARIES-AT5.29.2% (5.4)11.53.3360.140.595

ARIES-I Introduced SiC Composites as A High-Performance Structural Material for FusionExcellent safety & environmental characteristics (very low activation and very low afterheat).High performance due to high strength at high temperatures (>1000oC).Large world-wide program in SiC:New SiC composite fibers with proper stoichiometry and small O content.New manufacturing techniques based on polymer infiltration or CVI result in much improved performance and cheaper components.Recent results show composite thermal conductivity (under irradiation) close to 15 W/mK which was used for ARIES-I.

Continuity of ARIES research has led to the progressive refinement of researchStarlite & ARIES-RS:Li-cooled vanadiumInsulating coatingARIES-ST: Dual-cooled ferritic steel with SiC insertsAdvanced Brayton Cycle at 650 oCARIES-AT: LiPb-cooled SiC composite Advanced Brayton cycle with h = 59%

Advanced Brayton Cycle Parameters Based on Present or Near Term Technology Evolved with Expert Input from General Atomics*Key improvement is the development of cheap, high-efficiency recuperators.

Chart5

850565.1141069182872.5264028727

900594.2945353916922.8569335776

950623.1112021245973.00088364

1000651.57987089191022.9166118708

1050678.29732022081072.5843829725

1065687.71862207261087.0461265155

1080696.11810695341102.2856182468

1100707.2777346731121.3145693947

Maximum He temperature

Minimum He temperature

Maximum LiPb temperature

Gross Efficiency

Temperature (C)

Brayton Cycle He Inlet and Outlet Temperatures as a Function of Required Cycle Efficiency

Data

THERMAL-HYDRAULIC CALCULATIONS FOR HE-COOLED LIPB BLANKETREFERENCE

BRAYTON CYCLE CALCULATIONS

Cycle Temperatures

Max. He Temperature, Tmax(=T1) (K)11231173122312731323133813531373

Max. He Temperature, Tmax(=T1) (C)85090095010001050106510801100

Cycle Lowest He Temperature, Tmin (=T4=T6=T8)(K)308

Cycle Lowest He Temperature, Tmin (=T4=T6=T8)(C)35

Tmax/Tmin3.64610389613.80844155843.97077922084.13311688314.29545454554.34415584424.39285714294.4577922078

Helium

gamma, Cp/Cv1.66

gamma-1/gamma0.3975903614

Fractional Pressure Losses

Recuperator (each side)0.01

Inter-Cooler (each)0.0025

Heat Rejection HX0.005

Total out-vessel0.03

Blanket0.00982211650.01029319440.01077610490.01127165010.01176731920.01187875810.01209344470.0122085498

ITERATION WITH LINE 184 BELOW IN ITERATION SHEET

Efficiencies

Recuperator0.96

Turbine0.93

Compressor (each)0.9

Compressor

Compression ratio per compressor1.29219189481.3029800551.31357991211.32400203911.33611567241.33776380071.34075240831.3446335862

Turbine

Pressure ratio2.07306795412.12441392322.17562165152.22670265772.28723435292.29544998272.31036662962.3302172131

Pressures

P1 (blanket outlet, turbine inlet) (MPa)

Temperatures

T9 (Recuperator inlet, cold) (K)308308308308308308308308

T2 (Turbine outlet) (K)860.2021947065890.5984743663920.6158355464950.2706988457978.10137523987.9152313256996.66469474311008.289306951

T10 (Blanket Inlet) (K)838.1141069182867.2945353916896.1112021245924.5798708919951.2973202208960.7186220726969.1181069534980.277734673

T10 (Blanket Inlet) (C)565.1141069182594.2945353916623.1112021245651.5798708919678.2973202208687.7186220726696.1181069534707.277734673

Overall Efficiency

Parameter A152.6436775932168.4833113788184.7858059546201.5299055007219.5351384196224.1564944624229.3839500003236.4327542953

Gross Cycle Efficiency0.53580637480.55112953770.56528644340.57841062750.59062027360.59413612110.59753782130.6020355227

Comparable Carnot Efficiency0.72573463940.73742540490.74816026170.7580518460.76719576720.76980568010.77235772360.7756737072

POWER PARAMETERS INPUT

ARIES-RS Power Parameters

Fusion Power (MW)2171

330

Alpha Power (MW)434.2

Neutron Power (MW)1736.8

Neutron Multiplication Factor1.26

Total Thermal Power (MW)2622.568

4.03

5.67

0.4

0.47

5

39.4

55.4

Advanced Power Reactor

ARIES-RS X

From Neutronics Calculations

5

6.5

OB Ratio of Average to Maximum Wall Load0.85

IB Ratio of Average to Maximum Wall Load0.73

Fusion Power (MW)2170

Alpha Power (MW)434

Neutron Power (MW)1736

Neutron Multiplication Factor1.1

Current Drive Power (MW)50

Total Thermal Power (MW)2393.6

8.5

7.225

5.6

4.088

0.6

0.705

7.5

36.125

42.5

FIRST WALL HE FLOW AND SIC MAX. TEMPERATURE CALCULATIONS

He as FW Coolant

FW He Inlet Temp. (FROM BRAYTON CYCLE CALC.)(C)565.1141069182594.2945353916623.1112021245651.5798708919678.2973202208687.7186220726696.1181069534707.277734673

Maximum He FW Temperature Rise at Outboard Midplane(C)150

Average Outboard He FW Temperature Rise(C)127.5

Maximum He FW Outlet Temperature at Outboard Midplane(C)715.1141069182744.2945353916773.1112021245801.5798708919828.2973202208837.7186220726846.1181069534857.277734673

Average Temperature at Outboard Midplane (C)640.1141069182669.2945353916698.1112021245726.5798708919753.2973202208762.7186220726771.1181069534782.277734673

FW He Inlet Pressure (MPa)20

Properties based on Ave. Bulk Temp. at Midplane Outboard

1.07E+011.03E+011.00E+019.75E+009.50E+009.41E+009.34E+009.24E+00

Heat Capacity (J/kg-K)5.19E+03

Thermal Conductivity (W/m-K)3.38E-013.46E-013.54E-013.61E-013.68E-013.71E-013.73E-013.76E-01

Dynamic Viscosity (kg/m-s)4.33E-054.43E-054.53E-054.62E-054.71E-054.74E-054.77E-054.81E-05

Prandtl Number6.65E-016.65E-016.65E-016.65E-016.65E-016.65E-016.65E-016.65E-01

SiC Composite

3200

Fractional Theoretical Density0.95

Young's Modulus (GPa)360

Poisson's ratio0.16

Thermal Expansion Coeff. (ppm/C)4.4

k in plane (W/m-K)25

k through thickness (W/m-K)20

First Wall

SiC/SiC Tube thickness (m)0.001Plasma

Tube Diameter (m)0.006