DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26 MODELING A FILTER PRESS...
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Transcript of DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26 MODELING A FILTER PRESS...
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DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
Florent Jomard
Commissariat à l’Énergie Atomique
DEN/DTEC/STCF/LGCI
Site de Marcoule BP 17171
30207 Bagnols sur Cèze, France
Jean-Pierre Feraud
Commissariat à l’Énergie Atomique
DEN/DTEC/STCF/LGCI
Site de Marcoule BP 17171
30207 Bagnols sur Cèze, France
Jacques Morandini
Astek Rhone-Alpes
1 place du Verseau
38130 Echirolles, France
Yves Du Terrail Couvat
Laboratoire EPM, Madylam
1340 Rue de la Piscine
Domaine Universitaire
38400 Saint Martin d’Hères, FranceJean-Pierre Caire
LEPMI, ENSEEG
1130 Rue de la Piscine
38402 Saint Martin d’Hères, France
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODES
2/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
I. Introduction
II. The Westinghouse sulfur cycle
III. Modeling aim
IV. Coupling of physical phenomenawith Fluent® / Flux Expert® codes
V. Electrolyzer modeling, boundary conditions
VI. Software coupling results
VII. Conclusion, future prospect
3/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
Global warming context requires decreasing world's greenhouse gas emission
I. Introduction
hydrogen
alternative solution to replace primary energy
Exemple :
Hydrogen + fuel cells can replace internal combustion engines
CEA / PSA Fuel cells : GENEPAC ( GENérateur Electrique de Pile A Combustible)
PSA hydrogen concept car (207 ePure)
4/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
wide uses of energy = hydrogen mass production
High temperature cycles for hydrogen production
- 100% thermochemical : Bunsen Cycle…
- hybride cycle (Westinghouse sulfur cycle, Deacon cycle…)
- 100% electrochemical cycle (high temperature electrolysis of water)
I. Introduction
High temperature hydrogen production technologies could be provided by using :
- Gen. IV Nuclear power plants
- Thermal solar facilities…
5/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
H2, product½ O2
by product
II. The Westinghouse sulfur cycle Hybrid Sulfur Process block
H2Ofeed
Thermalenergy
Filter press Electrolyzer (50 – 100°C)
Concentration
Évaporation
Décomposition
Absorption
300°C
Concentration 300°C
Thermal Decomposition 850°C
Evaporation 600°C
Thermalenergy
Thermalenergy
H2O + SO2 + ½ O2 H2SO4
Electrical energy
Compression H2SO4
partSO2
part
H2S
O4
SO2
Cooling
SO2
H2O
SO2
H2O
SO2
H2O
Absorption25°C
Westinghouse sulfur Westinghouse sulfur cyclecycle
6/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
Process working conditions
-T°C : 50 - 100°C
- [H2SO4] : 20 - 60 % weight
- PSO2 1 bar
- Current density 200 mA/cm²
H+
H+
H+
H+
H+
H+
H+
H+
H+
e-
II. The Westinghouse sulfur cycle
membrane
Two compartment membrane electolysis cell :
AnodeAnode
++CathodeCathode
--SOSO22
HH22SOSO44
HH++
HH22
Anolyte : H2O-SO2- H2SO4 Catholyte: H2O – H2SO4
SO2 + 2H2O H2SO4 + 2H+ + 2e- 2H+ + 2e- H2
7/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
Within the framework of the Westinghouse cycle studies
The aim of our works consists of modeling a filter press electrolyzer
for hydrogen production.
III. Modeling aim
Our studies have to take into account numerous physical interactions :
- electrokinetic (overpotential),
- thermal behaviour (Joule effect),
- fluid dynamics (forced convection),
- multiphasic flow (electrolyte + bubble plume).
We expect that the virtual filter press design will work as a real one
8/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
IV. Coupling of physical phenomena with Fluent® / Flux Expert® codes
( )
( ) 0
( ) ( )p V S S
uu u g
t
ut
Tc u T k T Q Q
t
Physical phenomena :
- Thermohydraulics (Fluent, finite volume method)
Navier-Stokes continuity equations
Heat transfert equation
- CFD, Fluent model selected
- k-ε turbulence model so-called « realizable »- diphasic flow description : Euler-Euler - separate phase : disperse phases
n
ppqqqqqq mv
t 1
qqq
n
ppqpqqpqqqrqqqqqqqq FvmRgpvvv
t
1
momentum
Diphasic fluid dynamic
(1)(1)
(2)(2)
9/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
0 =V)(-.
.V-j
IV. Coupling of physical phenomena with Fluent® / Flux Expert® codes
Physical phenomena (continuation) :
- Electrokinetics (Flux-Expert, finite element method)
Charge Balance, Laplace equation :
Ohm's Law, primary current distribution (a):
RT
nF
RT
nF
eejj)1(
0
Secondary current distribution, Butler-Volmer's Law (b) :
Ele
ctr
od
e
Electrolyte
(j)
Pote
nti
al
(V)
Cell width
(a)
Inte
rface
gap
)j(f
j
n
nei
(1)(1)
(2)(2)
(b)
(a)
10/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
IV. Coupling of physical phenomena with Fluent® / Flux Expert® codes
Software coupling :
FLUENT® UDF Swap
functions
Main memory
Data files
FEcoupling.c UDF FEcoupling.c
Property operators : prxxxx.F
FLUX
EXPERT®
Main memory
Swap functions
Main memory
Main memory
Fluent®–Flux Expert® coupling flowchart
= message-passing function
physical phenomena can be solved by using different meshes (structured or unstructured)
Communication between the two codes : simple and robust message-passing library
algorithms developed are mainly location and interpolation algorithms
11/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
FLUENT®
Solve the two phase Thermohydraulic problem
Calculation ofTemp. (K)
in all the domainu (flow velocity)
αg (hydrogen concentration)
FLUX EXPERT®
Solve the Electrokinetic
problem
Calculation of U : Potential (V)
J : current densities (A.m-2) Qs/Qv : Thermal Joule effect ( W.m-3 )
Thermal and current densitiesinputs
hydrogen concentrationTemperature
IV. Coupling of physical phenomena with Fluent® / Flux Expert® codes
12/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
V. Electrolyzer modeling, boundary conditions
The FM01-LC laboratory scale electrolyzer : :
0.16m
0.04m
0.013m
H++H2SO4
H2SO4
+ SO2
H2SO4
+ SO2
H2SO4
H2
+-
zx
y
Electrolyzer operating principle
With : cathode, hydrogen release area , catholyte, membrane, anolyte, anode..
13/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
V. Electrolyzer modeling, boundary conditions
CA
TH
OL
YT
E
CA
TH
OD
E
mem
bran
AN
OL
YT
E
AN
OD
E
Overpotential Area
0 V
Y (mm)
Overpotential Area
Z (mm)
2000 A.m-2
CA
TH
OL
YT
E
CA
TH
OD
E
me
mb
ran
eA
NO
LY
TE
AN
OD
E
Flux-Expert
Hydrogen bubbles velocity : 0.01m.s-
1
bubble emission angle : 45°
Electrolyte uniform velocity profile
,,k,cp : temperature dependent
No thermal exchange with outsideHydrogen
area
160
mm
V= 0.07m.s-1 T=323K
V= 0.07m.s-1 T=323K
CA
TH
OL
YT
E
CA
TH
OD
E
me
mb
ran
e
AN
OL
YT
EA
NO
DE
0 1.5 6.5 6.6 11.2 13 mm
Fluent
Boundary conditions to produce 5 Nl.h-1 of hydrogen
14/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
1 2 3
VI. Numerical results
Residuals continuity u residual sulphuric acid u residual hydrogen v residual sulphuric acid v residual hydrogen w residual sulphuric acid w residual hydrogen T1 residual sulphuric acid
T2 residual hydrogen
K residual sulphuric acid residual sulphuric acid (1–K) residual hydrogen
FLUENT iterations
Code Coupling Behavior
Interaction between the two codes is demonstrated by the convergence of the computational residuals with successive iterations
FLUX-EXPERT iterations
15/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
T =323 Kυ = 0.069 m.s-1
T =323 Kυ = 0.069 m.s-10.16 m
0 m
VI. Numerical results
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
322 324 326
Anolyte Catholyte
Temperature (K)
Height (m) Thermal problem :
Graded colors scale
Temp. (K)
16/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
3 mm
VI. Numerical results
Cat
holy
te
Cat
hode
% H2 (vol.)
Cat
hode
Ano
de
membrane
Hydrogen plume area approx. 1 mm
Diphasic problem resolution :
Hydrogen volume fraction < 72%
Maximum concentation at 0.2 mm from cathode
17/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
VI. Numerical results
% H2 (vol.)
Cat
hode
Ano
de
Graded colors scale
0
10
20
30
40
50
60
70
80
0.0014 0.0019 0.0024 0.0029 0.0034distance from cathode (m)
hyd
rog
en c
on
cen
trat
ion
(%
)
h_0.15
h_0.08
h_0.01
height = 0.15m
height = 0.08m
height = 0.01m
Diphasic problem resolution :
18/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
Anolyte
VI. Numerical results
Fluid dynamic calculation :
Anolyte flow appearance:
Flat (uniform velocity) + wall effect on membrane and anode sides
Caracteristic of turbulent flow
Catholyte flow appearance :
Wall effect on membrane side,
High velocity increasing on cathode side (X4)
Characteristic of air lift effect
CatholyteFlow m.s-1
membrane
19/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
Anodic overpotential = 70 % tension of cell
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 0.002 0.004 0.006 0.008 0.01 0.012 0.014Lenght (m)
Ele
ctr
ica
l p
ote
nti
al
(V)
0,73 V
cathodic over
potential
anodic over
potential0.47 V
Tension of cell : 0.73V
Goal :
Design a cell to obtain 0.6 V of total tension
VI. Numerical results
Electrokinetics calculation :
Potential (V)V)
20/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
Modeling with Flux-Expert / Fluent Codes
Performed with message-passing library
Only 24h of calculation on Pentium IV(F. Expert) + Core 2 Duo (Fluent) PC
CFD results
Electrolyte rising temperature : 4°C
Catholyte motion (x4), hydrogen bubbly effect
Electrokinetics calculation
Electrochemical irreversible process taken into account with Flux Expert®
Total cell tension obtained : 0.73V (in accordance with literature results)
VI. Conclusion, future prospect
21/21
DEN/VRH/DTEC/STCF/LGCI JP FERAUD ICONE15, Nagoya 2007 April 22-26
MODELING A FILTER PRESS ELECTROLYZER FOR THE WESTINGHOUSE HYBRID CYCLE USING TWO COUPLED CODESICONE15 -10639
VI. Conclusion, future prospect
Calculation / Experiments
Experiments required to complete the lack of anodic overpotential law
Check Validity of diphasic flow behavior
development of specific physical operators
modelling a stack of cells before scaling-up
Optimization of the future electrochemical process with a design of numerical experiments