impact cape-b: critical power analysis code for bwr fuel bundle - evaluation method - analytical...
TRANSCRIPT
IMPACT
CAPE-B: Critical Power Analysis Code for BWR Fuel Bundle- Evaluation Method -
Analytical Step Calculation Method
4. Detection of Dryout
2. Spacer Effect
1. Fuel Bundle
3. Each Subchannel
3-D Subchannel Analysis with Drift-flux Model
3-D Liquid Droplet Transport AnalysisIn Turbulent Steam Flow
Liquid Film Flow Rate = 0
Liquid Film Flow Analysis
(a) Comparison of mass flux
Pressure : 6.9 Mpa Number of axial subchannel division : 50
Un-heated test (4 test runs)
Average mass flux : 651-2671 kg/m2sInlet subcooling : 1174 kJ/kg
Heated test (13 test runs)
Average mass flux : 719-1464 kg/m2sInlet subcooling : 68-603 kJ/kg Heated length : 1.83 mPower distribution : UniformHeat flux : 710-2130 W/m2
IMPACT
CAPE-B: Verification of Subchannel Analysis Model (1. Analysis of the test conducted by Lahey, et al.)
0
1000
2000
3000
4000
1000 2000 3000Measured mass flux (kg/m2s)
Cal
cula
ted
mas
s flu
x (
kg/m
2s)
4000
(Standard deviation)=7%
:Inner:Side:Corner
(b) Comparison of steam quality
0.1
0.2
0.3
0.4
0.5
0.1 0.2 0.3 0.4 0.5Measured quality
Cal
cula
ted
qual
ity
+e -e(Measurement error)e=0.024
:Inner:Side:Corner
0
PERI IN-3IN-1 IN-2
: 1.30: 1.15: 0.90: 0.45
Radial power distribution
0.6
0.2
0.4
PERI IN-1 IN-2 IN-3Region in bundle
Reg
iona
l ave
rage
voi
d fr
actio
n
0.8
Pressure : 7.2 Mpa
Mass flow rate : 1562 kg/m2s
Inlet subcooling : 50.2 kJ/kgAxial power distribution : UniformNumber of axial subchannel division : 48
IMPACT
CAPE-B: Verification of Subchannel Analysis Model (2. Analysis of NUPEC full scale bundle test)
: Present calculation: COBRA-BWR
Test data
IMPACT
CAPE-B: Concept of Liquid Film Flow Analysis
dGfdz
( Gf + dz
)
= dGfdz
(D - E - B)peA
Fuel rod
Dryout
Heat transfer to liquid film
Entrainment rate: E
Evaporation rate: B
Deposition rate: D
Liquid droplet
Inflow to the mesh: Gf
Mesh height
Outflow from the mesh(=Inflow to the next mesh)
Liquid film
dz
IMPACT
CAPE-B: Verification of Spacer Effect Analysis Model (Analysis of the test conducted by Nagayoshi, et al.)
(a) Test section
Hot wire probe
Rectangular duct
Plate spacer(Thickness: 0.5, 1.0 mm)
Flow
30 mm
10 mm
40 mm
Flow
(b) 2-dimensional analysis region
Rectangular duct
Plate spacer (Thickness: 0.5, 1.0 mm)
10 mm 42 meshes
70 meshes80 mm30 mm50 mm
Z
Z=0
Distance from the edge of the spacer (mm)
Incr
emen
t ra
tio
of t
urbu
lent
flu
ctua
tion
u'/u
' ∞
1
2
3
4
0 10 20 30 40 50
Thickness Exp. Cal.
0.5 mm
1.0 mm
IMPACT
CAPE-B: Turbulent Enhancewment due to the Spacer (Analysis of the test conducted by Nagayoshi, et al.)
IMPACT
CAPE-B: Test analysis condition for model validation
Bundle TypeNUPEC 88 EPRI 44
Bundle No. C2AFerrule Spacer, 1 W/R
Bundle No. IIIGrid Spacer, 2 W/Rs
Bundle No. 301Grid Spacer, no W/R
Pressure (Mpa) 5.5, 7.2, 8.6 7.2, 8.6 4.1, 6.9, 8.6
Mass flux (kg/m2s) 590-1,910 570-1,690 700-1,750
Inlet subcooling (kJ/kg) 20-130 10-125 50-610
Heated length (m) 3.7 3.7 1.8
Power Axial 24-step chopped cosine with p/f of 1.4 Uniform
Distribution Radial Local p/f: 1.30 Local p/f: 1.18 Local p/f: 1.02
Number of data points 70 72 38
Subchannel Axial 72 72 72
Division Radial 80 81 25
Spacer effect Coordinates Cylindrical Cartesian Cartesian
Analysis Mesh division 206488 404090 404090
W/R: Water Rod, p/f: peaking factor
1/4 Subchannel
Fuel rod
Ferrule type spacer
1/4 Subchannel
Fuel rod
Grid type spacer
IMPACT
CAPE-B: Two Typical Spacer Types
(a) Comparison at rated pressureIMPACT
CAPE-B: Validation analysis for BWR models (Analyses of the NUPEC 88 and EPRI 44 tests)
Ca
lcu
late
d cr
itica
l po
we
r (
MW
)
Measured critical power (MW)0
2
4
6
8
10
12
2 4 6 8 10 12
Number of data points : 116
Pressure : 6.9 - 7.2 MPa
Average difference : 0.5% =5.1% (Standard deviation)
-+
(b) Comparison with all dataIMPACT
CAPE-B: Validation analysis for BWR models (Analyses of the NUPEC 88 and EPRI 44 tests)
Measured critical power (MW)
Ca
lcu
late
d cr
itica
l po
we
r (
MW
)
0
2
4
6
8
10
12
2 4 6 8 10 12
Number of data points : 166
Pressure (MPa): 8.6 : 6.9 - 7.2 : 5.5 : 4.1
Average difference : - 0.3% =6.3% (Standard deviation)
+-
WR : Water rod
Bundle C2A, C2B
Bundle III
1.151.10
1.15
1.10
0.98
1.100.98
1.10
0.98
0.60
0.98
0.98 0.98 1.18 1.10 1.15
1.101.15
0.98 0.98
0.60 0.98
0.98 0.600.98
0.98
0.98 1.10
0.98
0.60
0.98
0.60
1.18
WR
0.98 0.98
0.99
0.75
0.99
0.99
WR
1.15
0.45
0.89
1.150.99
1.15
1.181.30
0.991.15
0.990.89
1.181.30
1.180.89
0.990.89
1.181.30
0.990.89
0.990.89
0.991.15
1.181.30
0.991.15
1.181.30
0.991.15
0.750.45
0.990.89
0.750.45
0.991.15
0.991.15
0.990.89
0.990.89
0.75
0.990.99
0.99
0.990.990.89
1.301.151.15
0.450.89
0.89
0.99
IMPACT
CAPE-B: Comparison of dryout locations
Dryout locations
Test Cal.
C2AIII and C2B
Bundle
Cri
tica
l pow
er
(MW
)
Mass flux (kg/m2s)
5
6
8
10
0 ~ ~
~~500 1000 1500 2000
7
9
IMPACT
CAPE-B: Effect of radial power peaking
Cal.Exp.
C2A
C2B
Bundle No. Spacer
Ferrule type
Radial power peaking factor : 1.30
Pressure : 7.2 MPa Inlet subcooling : 50.2 kJ/kg
Radial power peaking factor : 1.18
IMPACT
CAPE-B: Critical power difference by spacer type
Cri
tica
l pow
er
(MW
)
Mass flux (kg/m2s)
5
6
8
10
500 1000 1500 2000
7
9
~~ ~~
Cal.Exp.
Grid
Ferrule
SpacerBundle No.
C2B
III
Pressure : 7.2 MPa Inlet subcooling : 50 kJ/kg
Axial distance (mm)
Dro
ple
t tra
nsp
ort
ra
te
(m/s
)
0
0.1
50 100 150 200 250
0.2
0.3
IMPACT
CAPE-B: Droplet deposition characteristics
Ferrule Spacer
Grid Spacer
Spacer Location
: Ferrule
: Grid