Application of Supercritical CO in Nuclear Energy Systems · 4/7/2011 2 Background Supercritical carbon dioxide (S-CO2) is a very promising material for future applications encompassing

4/7/2011

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Application of Supercritical CO2

in Nuclear Energy Systems

Michael Podowski

Workshop on Supercritical Carbon Dioxide and

in Nuclear Energy Systems

Workshop on Supercritical Carbon Dioxide and Material Interactions

Brookhaven National LaboratoryMarch 21‐23, 2011

Center for Multiphase Research

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Outline Backgroundg

Application of supercritical fluids in nuclearenergy systems

Generic issues associated with supercriticalfluid systemsy

Recent advancements in the state-of-the-artin Supercritical Fluid Science and Engineering


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Background Supercritical carbon dioxide (S-CO2) is a very

promising material for future applicationspromising material for future applicationsencompassing a broad spectrum of fields andindustries

Possible applications include:- the use of S-CO2 as a working fluid in Gen. IV reactors:

either as reactor coolant in the Supercritical CO2 Reactorp 2

(SCO2R), or as secondary-system coolant in the SodiumFast Reactor (SFR) with S-CO2 Brayton Cycle

- the use nuclear power for CO2 sequestration and heavyoil extraction


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Supercritical CO2 Reactor (S-CO2R) Advantages:

direct thermodynamic cycle

high efficiency

Unresolved issues

effect of radiation on materials at high temperature

core neutronics (thermal vs. fast)

SCO2

core heat transfer

flow‐induced instabilities

accident mitigation


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Sodium Fast Reactor (SFR) with S-CO2 Brayton Cycle

SCO2

Compressor


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SCO2 Brayton Cycle

SCO2


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Advantages of Supercritical CO2 Brayton Cycle

Dostal et al. [2004]

Printed Circuit Heat Exchanger (PCHE)

• Size reduction of turbo-machinery• Good properties of SCO2 as reactor coolant• High efficiency of thermodynamic cycle

Dostal et al. [2004]


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PCHE and shell and tube heat exchangers with equal power

Geological Applications of Nuclear Energy Characteristic features of nuclear power systems

- practical limits on thermodynamic cycle efficiency: 50% orlless

- potential under utilization during low demand periods

Future utilizations of available thermal and electricenergy- hot water/steam from NPP heat rejection systems can be

injected into underground layers of heavy-oil-reachinjected into underground layers of heavy-oil-reachsandstone

- use of electricity during low demand periods for S-CO2

injection into deep oil and gas deposits and into heavyrock beds (sequestration)


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Heavy Oil Reserves


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Illustration of Nuclear Energy Use for Heavy Oil Extraction and S-CO2 Sequestration

Hot

Oil collection High

Energy storage and use

Hot water/steam

In

collection wellsCold

water out

gpressure/temp CO2


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Geothermal power andCO2 sequestration

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Geological Options for CO2 Use and Sequestration


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Generic Issues associated with Supercritical Fluid Systems

Fluid mechanics of variable-property fluidflow in complex geometries (compressors,mixing in large volumes)

Heat transfer (enhancement deterioration) Heat transfer (enhancement, deterioration)

Flow induced instabilities


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Key Characteristics of Supercritical Fluids No phase change

Hi h t t d th d i l ffi i

8

10

12

rand

tl

P=1.1 Pc

500

600

700

800

kg

/m3]

WaterCO2

High temperature and thermodynamic cycle efficiency

Dramatic changes in fluid properties in the pseudo-critical region

0.96 0.98 1 1.02 1.040

2

4

6

T/Tpc

Pr

CO2

Water

0.96 0.98 1 1.02 1.04100

200

300

400

T/Tpc

[ k

P=1.1 Pc

Normalized properties of water and CO2 at supercritical pressures


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Heat Transfer at Supercritical Conditions

Heat transfer enhancement occurs throughout theoccurs throughout the pseudo-critical region for low heat flux and high mass flow rates

Heat transfer degradation occurs at high heat flux and/or low mass flow rates


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Natural Circulation S-CO2 Loop


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Recent Advancements in the Analysis of Thermo-Fluid Phenomena in Supercritical Fluid Systems

Multidimensional CFD modeling and simulations

of fluid flow and heat transfer in heated channels

Flow-induced instabilities in parallel-channel

systems

Current studies include the modeling of S-CO2

compressors and loop dynamics and stability


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Turbulence Modeling at Supercritical Pressures

Conservation of mass

1

-0.5

0

0

Conservation of momentum

For turbulent flows with variable properties

P Ft

u

uu200 250 300 350 400 450 500

-4.5

-4

-3.5

-3

-2.5

-2

-1.5

-1

h [kJ/kg]

h [k

g2 /kJm

3 ]

0t

u u

where

Therefore derivatives in fluid properties may play an important role in turbulence modeling

i j j i ii j ji jj

u u u u u uux

uu u

uu

i ih

u h uh


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Derivatives of physics properties

-0.000003

-0.0000025

-0.000002

-0.0000015

-1.000x10-6

-5.000x10-7

4.1359x10-25

d

/dT

25 MPa

-30

-20

-10

0

d

/dT

25 MPa

300 350 400 450 500-0.0000035

Temperatue [C]

300 350 400 450 500-40

Temperature [C]


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Temperature Density Temperature Density

NPHASE Simulations of S-H2O H-T in Annulus

Temperature

(oC)

Density

(kg/m3)

331

360

390 679

450

221

Temperature

(oC)

419

506 679

384

Density

(kg/m3)

331 221

Fluid Temperature

Fluid Density

Fluid Temperature

Fluid Density

333 88

Centered heated rod Heated rod off tube center line


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Radial Property Distributions of S-H2O in Developing Flow

40

42

44

46x = 35 cm (297 kJ/kg)

x = 85 cm (331 kJ/kg)

x = 135 cm (366 kJ/kg)

1

1.2

1.4x = 35 cm (297 kJ/kg)

x = 85 cm (331 kJ/kg)

x = 135 cm 366 kJ/kg)

30

32

34

36

38

0 0.0005 0.001 0.0015 0.002 0.0025

r [m]

T [

o C]

0

0.2

0.4

0.6

0.8

0 0.0005 0.001 0.0015 0.002 0.0025

r [m]

u [

m/s

]

25

30

35x = 35 cm (297 kJ/kg)

x = 85 cm (331 kJ/kg)

x = 135 cm (366 kJ/kg)

600

700

800

0

5

10

15

20

0 0.0005 0.001 0.0015 0.002 0.0025

r [m]

c p [

kJ/

kgK

]

0

100

200

300

400

500

0 0.0005 0.001 0.0015 0.002 0.0025

r [m]

[

kg/

m3 ]

x = 35 cm (297 kJ/kg)

x = 85 cm (3313 kJ/kg)

x = 135 cm (366 kJ/kg)


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Predictions of Heat Transfer S-H2O

6

7

8

K]

Low ReHigh Re 80%(Prw,cp,w)

KAERIKAERIDittus-BoelterDittus-Boelter

12

55

60

65

Low ReHigh Re 80%(Prw,cp,w)

KAERIKAERIDittus-BoelterDittus-Boelter

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Low-Reynolds Model predicts wall temperature through pseudo-critical

0 30 60 90 120 150 180 2100

1

2

3

4

5

x [cm]

HT

C [

kW

/m2 K

1

2

0 30 60 90 120 150 180 21025

30

35

40

45

50

x [cm]

T [

o C]

BulkBulk

1

2

Low Reynolds Model predicts wall temperature through pseudo critical region better than High-Reynolds model

Predicted wall temperature after pseudo-critical region is slightly higher than experimental data

Effects of property variations on heat and mass transfer play a key role throughout boundary layer region


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Flow-Induced Instabilities


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Stability Analysis of Supercritical Fluid Systems

Parallel-channel mode Channel-to-channel mode


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Method-1: Channel Discretization

Continuity and energy equations are discretized

1

After algebraic manipulations and including the momentum equation

2

3

4

1 0n nnn

x xdyA

dt z

11, 0

2n nn n n

ss n ss

y ydy x xb G

dt z

( , )where

( , )n n

n n

x G t z

y h t z

N

0 ,1 1 ,2 2 ,

00 1 1 2 2

10 1 0 1 0 0

...

...

nn n n n n n

N N

N NN

dyx y y y

dtdx

P x y y ydt

x a x a x a P

where ( )o inx G t


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Method 2: Direct Frequency-Domain Solution Taking s = j, the real and imaginary components of

individual variables are separated, e.g.,2 ˆ ˆ ˆ

ˆ ˆ ˆ( ) ( ) ( )R IX j X jX 2

2

ˆ ˆ ˆˆ( ) ( ) 0R R I

I

d X dX dXz z X

dz dz dz

2

2

ˆ ˆ ˆˆ( ) ( ) 0I R I

R

d X dX dXz z X

dz dz dz

2 2

1 22 20 , ,0 ,0 ,0 0 0, ,

2 2ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ2

L L Lss ss L ss ss ss ss L

I R R R R R in out R Rss L ss ss ss LR ss L ss L

G G A G G G G AX dz X Y C X C Y dz g AY dz K K X Y

X

2 2

1 22 2

2ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆL L L

ss ss L ss ss LR I I I I I out I I

G G A G G AX dz X Y C X C Y dz g AY dz K X Y

ˆ1ˆ IR

dXY

A dz

ˆ1ˆ RI

dXY

A dz

Characteristic function of the system becomes

0

( )( ) Re ( ) Im ( )

( )

jG j G j G

X j

1 22 20 , ,0 0 0, ,2

R I I I I I out I Iss L ss LI ss L ss L

gX


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1-D Simulation of Flow–Induced Oscillations

Time-domain Frequency-domain


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Dimensional stability map Nondimensional stability map

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Current Research Directions - Fundamentals

Impact of variable fluid properties on kinematic

and thermal aspects of turbulence in S-C fluids

Importance of multidimensional phenomena on

dynamics of S-C fluid systems

Stability analysis of closed-loop systemsy y p y

Modeling of fluid flow and heat transfer in large

systems (mechanistic approach to porous media)


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Practical Applications of Fundamental Research

S-C Brayton cycle:

- Heat exchangers

- Flow in complex geometries (compressors)

Fl i d d i t biliti i l d l Flow-induced instabilities in closed-loop

heat transport systems


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Illustration: NPHASE-CMFD Simulation of Flow in Rotating Machinery


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Potential Future Applications

Efficient methods of analysis to understand

S-CO2 behavior in deep geological deposits:

- oil extraction

- sequestrationsequestration


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Thank you for your attention!


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Application of Supercritical CO in Nuclear Energy Systems · 4/7/2011 2 Background Supercritical carbon dioxide (S-CO2) is a very promising material for future applications encompassing

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