Natural convection flow in a cask storage warehouseFor Toyo Engineering

PHOENICS Version : 3.5.1

DETAILS :

• BFC grid • Three-Dimensional steady flow with heat transf

er • Buoyancy-influenced flow • Surface to surface radiation included • NX*NY*NZ=288*74*42=895,104

NOTES :

• The purpose of this model is to establish the temperature distribution and the air flow rat

e .

Geometry

x-y plane

nx×ny=288×74

x-y plane

nx×nz=288×42

outlet outlet

outlet outlet

Heat source

: 22.6[kw]

Air in

Air out

cask

External temperature

23.2℃

External temperature

23.2℃

Q

A2

A1

A1

A2Q

12

1

1

2

21

42

412 )(

AAAA

ATTQ

21 AA

21 AA

12

1

1

2

21

42

412 )(

AAAA

ATTQ

Radiation model in the cask

Result

Velocity

FlowRate[m3/s] per one caskExperimental　

data

Result of PHOENICS

0.28

0.3

Temperature

Natural convection flow in a nuclear reactorFor Denchuken

PHOENICS Version : 3.6

DETAILS :

• Cylindrical-polar grid • Three-Dimensional steady or transient flow with heat transfer • Buoyancy-influenced flow • Surface to surface radiation included • NX*NY*NZ=40*45*80=144,000

NOTES :

• When an accident happens in the nuclear system, eg the cooling system may fail. Hence, heat will be released solelyby natural convection of air flow. The purpose of this model is to establish the distribution of temperature and the air flow rate under these circumstances.

PRACS

IHX(Heat sink Q=-28.55[MW])

Liquid Na convection zone

Pump(11m3/min)Steady::onTransient::off

Radial shield

Reflector

Argon gas zone

Air convection zone

Air inlet(connected to stack)

Air outlet (connected to stack)

Air FlowLiquid Na Flow

Core(Heat source Q=30[MW])

Structure of porous media zone

power ration=Q/ 30

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.0001 0.001 0.01 0.1 1 10 100 1000

time [hour]

ratio

n[-]

Boundary conditions

Heat source and Heat sink:

Steady:-28.55[MW]

Transient:0[WM]

Steady:30[MW]

Transient: change profile

Pump power :

Fig. Pump coastdown curve

0.000

0.200

0.400

0.600

0.800

1.000

1.200

0.0 10.0 20.0 30.0 40.0 50.0 60.0

Time [sec]

Nor

mal

ized

flow

and

pum

p he

ad

Normalized flowNormalized pump head

Steady:11[m3/s]

Transient: change profile.

)( TTgF βρ

gF ρ

Body force (Buoyancy):

Liquid Na convection zone

Air convection zone

Resistance force in the porous medium zone:

2UKF

where

K: Pressure resistance coefficient. (This is different in each zone)

ρ:density

U： velocity

Radiation :

コレクタ

原子炉容器

安全容器

Q2

Q1

radiation

Q

A2

A1

12

1

1

2

21

42

411 )(

AAAA

ATTQ

A1

A2Q

12

1

1

2

21

42

412 )(

AAAA

ATTQ

21 AA

21 AA

Energy source in the porous medium zone :

S

x

Tk

xx

TCpU

t

TCp

ief

ii

liqiliqef

)(

liqsol

liqsolidsolidsolidef

solidsolidsolidliqliqliqef

VV

kVkVk

CpVCpVCp

1

t

TCpVS

x

Tk

xx

TCpU

t

TCpVsolidsolidsolid

ief

ii

liqiliqliqliqliq

)(

where

Pressure value in the air convection zone boundary :

PITOP

9,1 2,1

)(i i

fifiinoutin PPhhgP

9,1 7,1i i

fifioutoutout PPhgP

2

5.0

iin

ifi A

k

nP m

2

5.0

iout

ifi A

k

nP m

i Ai[m2] ki[-] n

1 1.0 0.3 2

2 1.0 0.25 2

3 - 0.657 2

4 5.28 1.3 1

5 3.48 0.76 1

6 1.26 2.6 1

7 - 0.3174 2

8 1.0 1.5 2

9 1.0 7.0 2

i=1 to 5 i=6 to 10

The value of pressure in the air convection zone boundary is renewed while it is calculated from the next experience equation.

POTOP

ΔPf1

ΔPf2

ΔPf3

ΔPf4

ΔPf5

ΔPf6

ΔPf7

ΔPf8

ΔPf9

Δhout

Δhin

POUT PIN

Δh

Result

Temperature distribution (steady)

Maximum temperature [ ]℃Experimental　

data

Result of PHOENICS

550

540.6699

Pressure distribution (steady)

Pressure drop [MPa] in Na convection zone

Experimental　data

Result of PHOENICS

2.5

2.51

2.9

2.95

3

3.05

3.1

3.15

3.2

3.25

3.3

3.35

3.4

0 10 20 30 40time[hour]

mass

flow r

ate

[kg/

s]mass flow rate[kg/ s]

Air flow rate in the air convection zone.

400

420

440

460

480

500

520

540

0 10 20 30 40

time[h]

tem

tratu

re[℃

]

Maximum temperature in the liquid Na convection zone.

Transient simulation in a vapor turbine

PHOENICS Version : 3.5.0

DETAILS :

• Cartesian grid • Three-Dimensional transient flow• NX*NY*NZ=222×218×98=4,742,808

下流側流入境界

Inlet of vaporInlet of vapor

Outlet

Air :Fixed temperature

Nozzle Box : Fixed temperature

RESULT

sURFACE TEMPRATURE IN POINT2

0

50

100

150

200

250

300

350

0 50 100 150

TIME(MIN)

TEN

PR

ATU

RE(

℃)

EXP DATAPHOENICS

SURFACE TEMPRATURE IN POINT1

0

50

100

150

200

250

300

350

0 50 100 150

TIME(MIN)

TEM

P(℃

)

EXP DATAPHOENICS

温度出力点

④ （ 90°）

鉛直断面

①（ 0°） ② （

30°）

③ （60°）

⑤（ 120°）

⑥（ 150°）⑦（ 18

0°）

水平断面

SLICE POINT1

POINT2