high heat flux peaking factors and enhancement

HIGH HEAT FLUX PEAKING FACTORS AND ENHANCEMENT

Ronald D. Boyd Sr., PhD, PE, PIDistinguished Professor, Honeywell Professor, Director of the Thermal Science

Research Center (TSRC), and TAMUS Regents ProfessorRoy G. Perry College of Engineering

Mail Stop 2525P.O. Box 519

Prairie View A&M UniversityPrairie View, TX 77446-0519

E-mail: [email protected]: 936-261-9962 or 936-261-9971Fax: 936-261-9974 or 936-261-5046

Annual Plasma-Facing Component WorkshopMassachusetts Institute of Technology (MIT)

Cambridge, MAJuly 8-10, 2009

mailto:[email protected]


OUTLINE BACKGROUND

Peaking Factor (Base-Line)ITER PFC MonoblockRecent LiteraturePassive Enhancement

SIMULATION METHODOLOGY SIMULATION METHODOLOGY RESULTS SELECTED EXPERIMENTAL PF DATA ONGOING WORK ACKNOWLEGMENTS


BACKGROUND

"ooq

φ

h(φ)

φ = 0 Deg.O 10

30

30

Unit mmAxix of Symmetry

Insulation

ri

Tb

Swirl Single-Phase Convection or Two-Phase Water Flow

Boiling (One Possibility For ITER)

H

w

Swirl Tape

r

φ = 0 Deg.

φ

h(φ)

t

Solid (k)

"

iwq

One Possibility (Base-Line Model) for PFC Monoblock High Heat Flux Removal (HHFR) for ITER. Another Possibility Uses a Hypervapotron Rather Than the Circular Flow Channel with a Twisted Tape. For DEMO, High Velocity Helium Gas and/or a Liquid Metal (e.g., Jet Impingement) Will be Coolant Candidates Rather Than Water.

max

")

"PEAKING FACTOR = PF wi

oo

q

q

PFC ITER Monoblock (M. Merola, Private Communication)

HIGH HEAT FLUX PEAKING FACTORS AND

ENHANCEMENTBACKGROUND

(continued)

maxwi)

As Noted by Escourbiac (December, 2008, Int.

HHFC Workshop, UCSD), Peaking Factors (PF)

are Used to Determine the Maximum Inside Wall

Coolant Flow Channel Heat Flux q From

the Monoblock Incident He "ooat Flux (q ).



(continued)

To this Presenter’s Knowledge, the PF Correlation by Boscary, Febre, and Schlosser

(Int. J.H.M. Trans., 42, 1999) Appears to be the Only One in the Technical Literature.

However, the Correlation was Applied Only to Glidcop A1-25 and Had No

Thermophysical or Thermal-Hydraulic Parameter Dependence for <

Critical Heat Flux (CHF) but Was Dependent on: (1) w/ri (2.66 < w/ri < 3.4), and (2)

t/ri (0.16 < t/ri < 0.6).

max

")wi

q



(continued) Federici and Raffray (J. Nucl. Mats., 244, 1997) Evaluated PF in

Copper Monoblocks With and Without 316 Stainless Steel Inserts.

Later, Raffray et al. (Fusion Engineering and Design, 45, 1999) Noted a Future Need to Better Assess PFs. PFs were Presented as Functions of t & w for a CFC Monoblock with a CuCrZr Tube Insert.



(continued)

PASSIVE HIGH HEAT FLUX ENHANCEMENT

In the 2008 Int. HHFC Workshop at UCSD, Escourbiac Noted That Enhancement is Possible When Defects are Located at = 0 degrees.

In 1994, Boyd (Fusion Technology, 25) Noted Enhancement is Possible for the Following Design Configurations:

Modified Channel Design for Improved Accommodation of HHF for the Single-Side Heated Configuration (qo = qoo and oo = /2).

.


ENHANCEMENT

Insulation

Plane of Symmetry

φoo "ooq

φoo

HHFR Fluidor Coolant

Plane of Symmetry

Insulation

Solid

φ = 0 Deg.

φ

rri

ro

h(φ)

Tb

Simulation for Base-Line PFC Monoblock.


ENHANCEMENTPF SIMULATION METHODOLOGY

"ooq

φ

h(φ)

φ = 0 Deg.

O 10

30

30

Unit mmAxix of Symmetry

Insulation

ri

Tb

H

w

Swirl Tape

r

φ = 0 Deg.

φ

h(φ)

t

Solid (k)

"

iwq

Plane of Symmetry

Greater Than 98% Accurate for Predicting PF and Peak Inside Flow Channel Temperature.Simulation Model Appears to be Applicable to Different

Monoblock Geometries, Monoblock Materials,Coolants, and Coolant Flow Regimes.

PF = f(t, w, H, ri, Bi), *hwhere Bi = Biot Number = .i

r

k

Note: Another Possibility for HHFR is the Hypervapotron, and it will be Added to this Work.


SELECTED EXPERIMENTAL PF DATA


Ref G P out Δtsub H1 H W Materials k ref r i Φi Φc PF

# (Mg/m2s) (Mpa) out (mm) (mm) (mm)

(W/mK) (mm) (MW/m2) (MW/m2

) Peaking

Mass Vel Exit ( °C ) ICHF Max Factor

or V P CHF

{m/s} at Wall

Fluid Vel

1 (15) 3.6 176 2.4 14.8 17 Cu- Al2O3 5 44.7 65.7 1.47

1 (10) 3.4 171 2.4 14.8 17 Cu- Al2O3 5 36.5 53.5 1.47

1 (15) 3.6 133 2.4 14.8 17 Cu- Al2O3 5 34.2 49.9 1.46

1 (10) 3.4 126 2.4 14.8 17 Cu- Al2O3 5 29.8 43.5 1.46

1 (15) 3.6 87 2.4 14.8 17 Cu- Al2O3 5 26 37.8 1.45

1 (11) 3.5 84 2.4 14.8 17 Cu- Al2O3 5 19.2 27.6 1.44

1 (16) 3.2 63 2.4 14.8 17 Cu- Al2O3 5 23.8 34.5 1.45

1 (16) 2.4 155 2.4 14.8 17 Cu- Al2O3 5 45.7 67.1 1.47

1 (14) 2.3 152 2.4 14.8 17 Cu- Al2O3 5 42.6 62.5 1.47

1 (16) 2.5 114 2.4 14.8 17 Cu- Al2O3 5 31 44.9 1.45

1 (15) 2.7 71 2.4 14.8 17 Cu- Al2O3 5 22.8 32.9 1.44

1 (14) 1.3 125 2.4 14.8 17 Cu- Al2O3 5 37.3 54.7 1.47

1 (10) 1.2 117 2.4 14.8 17 Cu- Al2O3 5 29.5 42.9 1.45

1 (5) 1 104 2.4 14.8 17 Cu- Al2O3 5 21 30.6 1.46

Boscary.J, Fabre. J, Schlosser J., “Critical Heat Flux of Water Subccoled Flow in One Side Heated Swirl Tubes” (Int. J.H.M. Trans., 42, 1999).


CONCLUSIONSA Conjugate Heat Transfer, High Heat Flux Simulation Methodology has Been Developed Which Accurately Predicts the Flow Channel: (1) Radial Heat Flux PF to Within Less Than 2% Inaccuracy, and (2) to Within Less Than 1%.Work is Proceeding to Extend This Simulation to PF and Correlations Which Include the Basic Monoblock Geometry, Fluid, and Thermal-Physical Parameters.

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ONGOING WORK

Simulation PF Correlation Development Related Data Search

Model Validation/Verification

PF

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Inside Surface Heat Flux Map For An Externally Applied Single-Side Heat Flux, Where q = qo= constant and oo = /2.


ACKNOWLEDGMENTSTHE THERMAL SCIENCE RESEARCH CENTER (TSRC) IN THE COLLEGE OF ENGINEERING AT PRAIRIE VIEW A&M UNIVERSITY IS APPRECIATIVE TO THE OFFICE OF FUSION ENERGY SCIENCES PROGRAM (U.S. DEPARTMENT OF ENERGY, DOE) FOR ITS SUPPORT OF THIS WORK UNDER CONTRACT #DEFG02-97ER54452. FINALLY, THE AUTHOR IS APPRECIATIVE TO MR. AARON M. MAY, MR. FRANCOIS MARTIN, AND MS. VIVIAN GLOVER FOR THEIR STEADFAST SUPPORT.

high heat flux peaking factors and enhancement

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