Upload
dinhkhuong
View
219
Download
0
Embed Size (px)
Citation preview
HWAHAK KONGHAK Vol. 41, No. 2, April, 2003, pp. 192-201
50 kW
*†** ****
121-742 1
*LG ()550-805 754
**LG-Caltex () Value Creation Center 305-380 104-4
(2002 12 2 , 2003 1 16 !)
Flow Sheet Simulation and Control Structure Designfor a 50 kW Phosphoric Acid Fuel Cell System
Ji S. Lee, J. Kim*, Kwang S. Lee†, Hee J. Lee** , Jae C. Yang** and Seong H. Seo**
Department of Chemical Engineering, Sogang University, 1, Shinsoo-dong, Mapo-gu, Seoul 121-742, Korea*LG Petrochemical Corp., 754, Chungheung-dong, Yosu 555-805, Korea
**Value Creation Center, LG-Caltex Oil Corp., 104-4, Munji-dong, Yusung-gu, Daejeon 305-380, Korea(Received 2 December 2002; accepted 16 January 2003)
, ! "# $%&
'( ) *+ ,- ./0. 12 '&34 )5 67- 89 :;*+ - <(= >?
@, .+ *+ - <( A BC D= E0. F G HI 89JK3L HYSYSM I- 9N
OPJKM DQ 50kWR LST .+ *+M OUV0. .+ *+G WX Y =
Z :[\ .]^G ._ 89`OM .a ZL= Z0. F G 0b- JKcd5 ef O
g Ih5 i .`O j)a Z5 kV0. l Og Ih m9 =no M p9 qmJr5 7
s kV0. .]^M tA , - LST .uM kV0.
Abstract - Despite the keen and continuous interest in the fuel cell system as an alternative electricity generation system,
the research has been confined mostly to the electrode material development and stack design. Sometimes, optimal design
of the integrated system has also been reported. On the other hand, research on control system design has been scarcely pre-
sented even though a fuel cell system may be subject to frequent load change during operation. In this study, a control sys-tem structure for a 50kW PAFC (Phosphoric Acid Fuel Cell) system has been presented based on steady state simulation
studies using the commercial flow-sheet simulator, HYSYS. The prime difficulty encountered in the fuel cell control sys-
tem design against load change is that it is not clear which process variable should be regulated in the primary control loop.
In this study, through extensive simulation study, the hydrogen utilization ratio has been chosen as a regulation variable for
the primary control loop. Since the hydrogen utilization ratio cannot be measured directly, an inference model is devised and
proposed, too. On the basis of the concept of the primary control loop, the control structure for the whole PAFC system has
been suggested.
Key words: Phosphoric Acid Fuel Cell (PAFC), Control System Design, Load Change
1.
( )
!" #
$ % &'()[1]. ( *+ , -
./01 234 /05 6 71 8 9: ;<=+ >
?@ AB CDE FG<H (AFC), IH (PAFC),
JK LM (MCFC), 3 NH (SOFC), OP
QH (PEMFC) R CS T%( UV W
). IH ( X & YZ [ V\ O](^, _†To whom correspondence should be addressed.E-mail: [email protected]
192
50 kW 193
`a "B bc Wd). ef(= gD, hi RE 2jk
l mnJ 11 MWn, o< jk OHI 200 kWn pqpr
1 CC st5^, IFCu ONSIvE 200 kWn PC25TM1 `a
@ `w()[2, 3]. @x DyE IH z; 1993|
[ ~Wd 50 kWn T% &'(I,
TQ) T%( (dU `w(^ @ ( pJ @ [
UV XI `()[4].
" m$Z TQ, , , C
5 = ). `a\ % T%1
E ( C " m$ T% + CC " m$1 B4
( 9 d d T%( ().
|4 2 d T%Z
9 + 1 24 (+
). @ [ X & ¡%@ O] (=
T% @ ¢5 (g `£ [¤¥ ¦Wd 5^, TQ
u 1 B4 m$ § ¨ @ [© ª« %¬W
). o= 9¥ ®\ |4 24 @ d/0
2@ [ ¯ °; g>@ `w()[5].
f [E LG-Caltex $h()E T%@ 50 kWn IH
%1 2`5 4 ±L/²1 ³ 4 TQ &',
o< C &' B4 m$ kv `aJ m$
kvI HYSYS (J4 [4 , ( (J4 |4´ $` `
w kv V4µ5^, o ¤¥ ¶5 m$ 9 1
O,4µ). o< o ¤¥ ¶5 |4 24 @
d /0 T·1 4 P 4µ).
HYSYSE m4 m$ k¸( TQ= R
m$1 kv4 ¨4 ¹Z |O( d © m
$ k¸1 T%4µ5^, (º T%\ kv p m$ 9
¤¥ » ¬¼1 ½I4µ).
2.
2-1.
2` Z LG-Caltex $h()E ~4 9 XI
50 kWn IH m$ ¾¿© Fig. 1¥ À). Á&'
(HDS) _ Ã(±L) ²¥ ¼Ä ejector Å¥@ Æ ÇÈ
(LTSC)u ÉÊË1 _Ì TQ(reformer) mn\). T
Q @ ÉZ Í°(catalytic combuster)E ÎÏ
È u ÉÊË mn\). TQ ( ÐÑ 3 È
(HTSC)E eÒ5 CO _W^, ( Ó g
3(anode-off gas)u ÉÊË1 4 \). o Æ LTSC Å¥4 CO
Ô© 1%gÕ5 ÖU). CO _\ 3 ×5
mnWd Ø u 4 u q Î4 \).
q Ø mu Ù =Ú , g 3 Í°
WbÛU). C ²5 4 e|
ÜÝW , TQ ³ vJ\).
TQ LG-Caltex $h()E ÞßH5 àB, ~@ ¢5
- ³ÅH TQ > à' á( ~ , Þß á â
*+ Îã1 ä ) &å1 ). CO
_4 vJW ÇÈ È © kæ ÞßH5
~Wd TQu ¼Ä â¼5ç 3 mª1 4 TQ
u ÉÊË( J(4©è 4µ)[6, 7]. ×Z 10 wt% Pt/
C Í°, ØZ 20 wt% alloy Í° vJ4 ). " h
áZ 3,600 cm2(^ " 100"( âWd 1 [4
).
2-2.
2-2-1. TQ
é Í° (J@ TQ ±L1 TQê Ô© Î4
" m$(). TQE ed= Z )×¥ À).
Fig. 1. Process flow diagram of the 50 kW PAFC in LG-Caltex Oil Corp.
HWAHAK KONGHAK Vol. 41, No. 2, April, 2003
194 !"#$%&
(1)
TQZ 35 ë@ ìÉ 5 È Çí äî 4
$ UV( h<4). e5 TQ 650-900oC È
E 9W^ f [ 2` Z 700oC |ïE 9@). Þ
ßH TQ TQ ( ed= ÇÈ|u Í° Å¥@
È Å¥4 È| [Wd 5^ ( æ |O1 =¦
9: Þß1 Å4 @ É( ÇÈ| ð\). (
Ó ÇÈ|u È| NQ ¾¿Z ñò \). ÞßH TQ
HYSYS [4 E z/ñ Oó ô@ 1Ò³ õâ
ïv4 kö1 ÷4µ). ø ù [35 3
10T "É ú¾¿ Ê(CFSTR) =¦ Fig. 2u À(
C ÎN( Í° È u ÉÊË1 _Â Æ )
× d©è [4µ). p m$Z TQ ÇÈ|u
È| ¾¿ c[ È© d two point zB' û dU
). ( ü 4 HYSYSE È| Ý[ È© $4
;ý/ñ5 UV4^ [@ Æ TQ ÇÈ| Ý[ È©
720oC e'4 ½I4 , ( þ( e' Óÿ È| Ý
[ È© $4 shooting method (J4µ). TQ Z
Kaihu Hou R[8] \ Ni/a-Al2O Í° `E ú©
¥ ÞH ` vJ4µ).
TQ Í° `E ed= Z HYSYS J
1 ¢5 Visual Basic o5 reaction extension1 [
4 kv V4µ). HYSYS (J B\ TQu É
J È È© Oóu y Î Ô© O
ó Fig. 3, 4u À).
2-2-2. Í°
Í° anode-off gas= ±L1 êE TQ
@ É1 mn4 e1 £@). Í° E ed= \
Z )×¥ À).
(2)
(3)
Í° anode-off gas ê TQE @ É1 m
n4 P 4µ Óû 2|O z; (2) ( Ü4^,
(3)Z 5 ±L1 ê] 4 z;Õ edÑ). Í°
HYSYS y "É Ë [4µ5^ Ë Z 100%
$4 kv V4µ). ", (¢Z
õO@ Ø mn ÓÕ h4).
2-2-3.
TQ ( ÐÑ 3 7-12%$© CO ó¼Wd dE,
( o2 5 mn4 Wá Í° W
CO Ô© 1%(4 Ö ¢( 4). E CO
qu 4 CO2 ÎW u ÀZ ( edÑ).
(4)
( Z %É5 È© Ö1è ÞH` q4 W
Z Ë 1 E ÇÈ ( h<4^ íl ñ1 8
¹). o< Ø> (` q mn z; Ë ( `4
\). IH E ú© ( Ç
CH4 H2O CO 3H2+↔+CO H2O CO2 H2+↔+
CH4 2H2O+ CO2 4H2+↔----------------------------------------------------------------
2H2 O2+ 2H2O↔
CH4 2O2+ CO2 2H2O+↔
CO H2O+ CO2 H2+↔
Fig. 2. Realization of the reformer for simulation.
Fig. 3. Typical temperature profiles in the reformer.
Fig. 4. Concentration profiles of each component in the reformer.
41 2 2003 4
50 kW 195
,
HTSC(260-370oC) vJ4 , Z Ë 1 LTSC(200-
260oC) vJ4 2" Hw x(). "É ÞH
$4 , HYSYS [4µ). p 2`
Ë (90%)¥ HYSYS y ÞH (J@ kv
V ¤¥(Ë 88%) >@ ¢5 E ( $ ´ ô<
¢5 ß"\).
2-2-4.
2-2-4-1. Cell
2-2-4-1-1. l
Fig. 5Eu À( (anode), (cathode) o
< Q [\). E (È¥ P =
( edÑ). (ÈZ Q1 Å¥4
5 (4 , P |. Å4 5 ª).
E u (È o< P 4 N( Î\).
CellE ed= 1 ÅE u É 1 ).
cell lZ Nernst 5 ¬\)[9].
(5)
(5) dU cell lZ `wE 1 (
` l(). (¢Z ( l( |4ý5 ò < ¹5^
ý$ Ó == þ1 g4^, ò ¾ ~4á >
`( == l( ÖU). ( > `1 (4
¢Z cell ÷ dE °; X4)[9].
íë4 ` ³I5 activation overpotential, fuel crossover
Oíë4 @ íë4, Ohmic loss R1 ). k! >
1 Û4 ¬\ cell 9 l Z )×¥ À( ïv5
¬ )[9].
(6)
(6) HI þZ " û#[9] Wd 5^, ( þ
1 X$5 2` ` þ1 pr' regression4 ¤$
4µ). Fig. 6 (º [\ cell l kö¥ 50 kWn IH
9 :( >Ê4µ5^, >Ê %Z e'
( ¢1 ½I ).
E E0 RT2F-------
PH2PO2
0.5
Ptot0.5PH2O
-------------------
ln+= E0 Gf0∆
2F----------=,
V i( ) E i in+( )r– Ai i n+
i0----------
ln B 1i i n+
i l----------–
ln+–=
Fig. 5. Basic concept of the fuel cell.Fig. 6. Comparison of the cell voltage true the model with experimen-
tal data.
Fig. 7. Stack model as a distributed parameter system.
HWAHAK KONGHAK Vol. 41, No. 2, April, 2003
196 !"#$%&
2-2-4-1-2. Cell kö&
Z f5 O '+gB(). (5)E© F ((
" C åE u Ô© Oó 4 l O
ó %Î4 W , ( I4 ò)© Oó© Î \). (
1 '*4 )×¥ ÀZ $1 ©c4 B1
V4µ)[10].
4= " j+kT CFSTR [Wd )(Fig. 7).
" CC cellZ ,- ¤\ u À5
Kirchhoff 0.1 Õ/@)(Fig. 8).
" yE È© Oó ô@).
u À( 1 O '+gB $@ äîE B\ cell
HI ò)© Oókv Fig. 9u À). o0E© 1 ((
ò)© Ò( §2 10-15 mA/cm2 ¹ ¢1 ½I4µ5^,
( ¤¥ ï_4 cell O '+gB 1 ô4 2 '
+gB $4 kö&1 V4µ).
2-2-4-2. kö&
Cell >1 Û@ kö1 HYSYS y k¸ [
d Visual Basic1 (J@ operation extension1 [4 HYSYSu
4 B4µ). Fig. 10Z k¸1 ª" ¬@ ¢().
3 E 4n@ u À( 1 2Â '+gB $4 ¢
( ô< 5, HYSYSE© 1 2Â '+gB $4
É NQ $``w 1 ÷4µ). 5, " yE
u , q Ô© 6e4^, C å ò)©© e$4
) $4µ). Z |4 Ç7(R), ×¥ Ø, C c
[ äî, C Ý[ ílZ d8) $4 ÷4µ).
(J9Z §2 85% (`1 :d; ) $4µ).
NQ
H2: (7)
O2: (8)
É
(9)
(10)
ma1yalH2 ma2ya2
H2– nSi2F--------– 0= η 1
ma2ya2H2
ma1yalH2
---------------- 0.85≤–=,
mc1yclO2 mc2yc2
O2– nSi4F--------– 0=
ca1ma1Ta1 cc1mc1Tc1+( ) ca2ma2 cc2mc2+( )Ts–
UA Ts Tw–( )– nSi2F-------- Hf
H2O∆– R Si( )2– 0=
UA Ts Tw–( ) qm λw– 0=
Fig. 8. Equivalent circuit representation for the Kirchhoff's law.
Fig. 9. Current density distributions in the stack.
Fig. 10. Stack model for the heat and material balances.
41 2 2003 4
50 kW 197
(7)¥ (8) A <= 7Z CC E u kã1
g@). 2-2-5E ù `A àWÕ È© >@ @
6e4 h4 4 C ó`w N mnW ¥
ÉÊË o X e| q ËW ` 4
¢5 $4µ). ¥ (6)1 ÷E 2@ B
1 V4µ). Fig. 10E |4(R)¥ Ø¥ × cläî
C cl äî( dá =? þ( BW©è 4µ). C
È© Tw Fig. 1 ² @ íl1 ä¼5ç ¤$W^
170oC hA).
2-2-5. C
yE %Î4 @ ÉZ `£ B
E ( _4 ¹5á y| È© `5 I y[
( C`\). *+E ( /4 @ C [ä D
4)[11].
IH $ 9È© 180oC |ï(^ >@
cell y È©Oó §4 ¢( %). È© =' á
Q vJW I q%ã( BE û Î^, È© Ö
á ú© ÖE û %Î@). (@
$ È© ¥5 h 4 C ó`w N m
nW ¥ ÉÊË o X e| q ËW `
4©è [4µ). Fig. 1E 1 ¢¥ À( q
ó¼@ C ² @ ËòWd N¥ q O<\). ²
@ ventØ1 ä~4 íl1 ä4©è 4µ5^ ( íl à$'
4 ó`w C È© ¤$\). C È© 170oC
hA).
3.
HYSYS5 [@ IH % $``w kv
oZ Fig. 11¥ À). kv äîZ )×¥ À). ;F TQ
mn4 ²/L G> 2.76(^, TQ Ý[ È© 720oC
e$4 h4µ). e5 9 Ø m ¥ã
5 mn4 z;, C .W Éã( ~E ² Îã(
Hd + IJ > l© B \). o 9
ñ1 ¹ K yE Cp1 §
@ (J91 ¤$4 ¢( 4). 1 O '+g
B $4 kv V@ ¤¥[10] (J9( 30%(`I
z; o (4e Ó ) Îl( nL M4 ¢1 F
N). *+E @ (J9Z 30% $4 $``w k
v V4µ).
3-1.
HYSYS [@ % kv >1 Þ4
4 LG-Caltex $h() p 9 :(u o ¤¥ >
Ê4 O). 9 :( CC 50% |4u 70% |4E Z ¤
¥(). Table 1E 1 (( kv p 9 ¤¥
» Pý4 ×1 F ). ( 100% |4 2@ ¤¥©
%Z e' µ).
3-2.
3-2-1. d F
dB [E & Ç ¤$Wd] 4 ¢Z
|4 (ש Q[4 e$@ þ1 hê]4 d
ôR5 F4ST 4 ¢().
;FZ Cell í1 ÎC 1 ). Z |4 5,
m$E [4 ò)© m$ 5 ª4á ò)©
*+E í© 4 ( )(Fig. 6). d
äî X 4= |4 ( ù+© e$@ þ5 hWd] 4
¢( Cell í1 d à$4 ¢Z U V4).
)×5 (J91 ÎC ). (J
Z |4 %Î4ù+© ³ã1 W(_= HE e$@ þ5
h 5 §2'I 85% (4 ) ÖZ þE ä4
Fig. 11. Process flow diagram of the 50 kW PAFC(HYSYS).
HWAHAK KONGHAK Vol. 41, No. 2, April, 2003
198 !"#$%&
áE |4 2( >4). @ (J91 ¯X ý$4
dÛ;= $4 ¢Z >4). 3 kv¤¥| Îã
1 £@ $)© Pý4 ¢( >¼1 ½I 5^, (Ó |
4 ¾ ò| "ª£ kW ã1 $
5 (J91 B ). vp TQ
E vp` ÞH ( (d È©u íl o< ³ m
nã1 F 5á kv (J4 ¹ù+© dÚ Ø
1 $ ). *+E f [E (J91
d F4µ). Fig. 12 (J9 $ T·1 µ).
E à@ (J9 d @ ª"@ P dá,
(J9( 70%+ $4á, |4 q4á TQE
%ÎW ãZ e$4 (J9Z q4 \).
o= (J91 70% h4 ³(±L)u Í°
d m hã1 ©è d ~( pVWá
Table 1. Comparison of simulation results with experimental measurements
(a) 50 kW PAFC under 50% Load
Simulation results Experimental results
Stream Reformer in Reformerout HTSC out LTSC out Reformer out HTSC out LTSC out
Flow rate(kmole/h)
H2 0 1.056 1.1456 1.231 1.0708 1.1511 1.12271CO 0 0.172 0.0823 0.0049 0.1597 0.0795 0.0034CO2 0 0.1494 0.239 0.3164 0.1623 0.2425 0.3185H2O 1.1111 0.6404 0.5508 0.4733 0.6269 0.5466 0.4706O2 0 0 0 0 0 0 0CH4 0.228 0.0039 0.0039 0.0039 0.0033 0.0033 0.0033C2H6 0.025 0 0 0 0 0 0C3H8 0.0123 0 0 0 0 0 0C4H10 0.0026 0 0 0 0 0 0
(b) 50 kW PAFC under 70% Load
Simulation results Experimental results
Stream Reformer in Reformer out HTSC out LTSC out Reformer out HTSC out LTSC out
Flow rate(kmole/h)
H2 0 1.4389 1.5781 1.672 1.5069 1.6059 1.6973CO 0 0.2493 0.1104 0.0159 0.1977 0.0986 0.0072CO2 0 0.1929 0.3321 0.4261 0.2485 0.3476 0.4390H2O 1.35 0.7149 0.5757 0.4816 0.6553 0.5562 0.4648O2 0 0 0 0 0 0 0CH4 0.3192 0.0134 0.0134 0.0134 0.0091 0.0091 0.0091C2H6 0.035 0 0 0 0 0 0C3H8 0.0172 0 0 0 0 0 0C4H10 0.0037 0 0 0 0 0 0
Fig. 12. Estimator of the hydrogen utilization ratio.
41 2 2003 4
50 kW 199
%Îã( qE (J9Z 70% e$4 h ¢().
3-2-2. @ (J9 F
E @ (J9 d T·1 ©c4 E @
(J91 ¤$4 ¢( 4). ;F Y$ ýáE 1 Ó §
2'I 85% (4 þ(á ô û ). o= z ýá1
Û Ó >@ @ anode-off gasÕ5 TQ É1 mn4 ¢
( (). f [E æ ýá1 Û4 @
(J9 þ1 F4µ). (J91 ô Ö F4 ¢Z v
JW ¹1 Q4 Y( Î4 ¢( W >
(). (J91 ô (á m$ ýáE h<4= |4
q 24 @ h |/ + ¤Z5
ô< Q >( ). @ anode-off gasÕ1
êE TQ @ É1 mn 5 Í°
5 ±L1 mnd] @). *+E >@ @ anode-off
gasÕ5 TQ @ É1 mn 5^, @ (J
9 h [ þ1 F4 ¢( 4).
@ (J91 F4 4 ÎlZ 50 kW |ï5
h , (J91 ê áE $``w kv
Vf ¤¥ Table 2u ÀZ ¤¥ N). (J9 72%u
77% I æ z; anode-off gasÕ1 \5 TQE
@ É1 õ/ N). o= (J91 80% à$@ z
; I ±L mn( 4µ). Î l( 33 kW,
40 kWI z; anode-off gas Õ1 ê TQ @ É1 m
n §2 (J9Z CC 70%, 72%(N).
" Table 2 (J *] .ã > 1 ¼Ä
µ). 50 kW9 mnW ^ (±L É) X d
.W > Z 43-47%(N , ²5 .W > Z 8-
11% (N5^, (J9( 1è . ( ¢
1 ½I N).
3-3. ! "#
|4 ( %Î4ù+© (J91 e$4 h4 E
eÒ5 ³ mnã( ] ¼1 3-2-1E 4µ). (
d0( 2 JW E |5 TQ È©© e$
4 h] @). anode-off gas Ø( 4 Wá Í°
E %Î4 Éã( 4 TQ È©© 4 \). T
Q È© Îã 4 \). *+E |4
( %Î4ù+© TQ È© e$4 h4 E Í
° mn4 m hã1 4_ á I ±
L mn( 4 \). TQ È© æ T ä~(mhã,
±Lhã) vJ4 @ split range d(P d cl`a
50% (4e Ó ±L mn q, 50% (`e Ó m hã q)
Å e$4 h ).
TQ È© d4 @ ä~ Í° mn4 m
hã1 F4 z;, dcl(m hã)¥ m$Ýl(TQ È©)
` B F 4 33 kW |4e Ó Í° hcW
m hã1 ê áE TQ Ý[ È© B4 O).
Fig. 13E 1 (( m hã( q¼ *+E TQ Ý[ È
© Ö ¢1 1 ). o TQ Ý[ È© à$'
) Z z; m hã1 W<á ³4 È© ÖÝ ).
TQ Ý[ È© q E Í° ±L1 mn
4á \). |4 q4á $E B\
(J9( q4 \). oá ³(±L)ã( q4W , (
*+ ² Ø© q@). @ (J9( q4á anode-
off gas Ø( M4 W , TQ È© e$@ þ5 h4
4 I ±L¥ ( ©è m mnã©
q4] @). Fig. 14 C |4´ $``w ©ðb1 Ó
>cF(). o0E© 1 (( |4q *+ > cFZ M
4 zñ1 =d). |4 58 kW( (J9 70%)e Ó anode-
off gas E §@ 5.5 kmole/h mnWd]
@). |4 33 kWe Ó( (J9 70%) Í° mnW
mãZ 6 kmole/h(). ( |4 58 kW q4© anode-off
Table 2. Energy recovery from the 50kW PAFC system
Hydrogen utilization ratio(%) 72 77 80
CH4 Input To reformer*(kcal/h, (%)) 119078(100) 111705(100) 107237(100)To catalytic combustor*(kcal/h) 0 0 11187
Output Electricity(kcal/h, (%)) 50654(43) 50654(45) 50654(47)Steam(kcal/h, (%)) Latent heat 8424(7) 8647(8) 9470(9)
Sensible heat 1699(1)** 1764(2)** 1932(2)**
*Heat of combustion with reference state 25oC, 1 atm gas** Reference state: water at 70oC
Fig. 13. Reformer outlet temperature profiles as the air flow rate of cat-alytic combustor.
Fig. 14. Air flow rate to the catalytic combustor required the reformertemperature at 720oC under load change.
HWAHAK KONGHAK Vol. 41, No. 2, April, 2003
200 !"#$%&
gas Ø(). o m mnãZ ±L
@ ØÕeÕ q4á \). Í° mnW ±L
Ø1 Bú WÛáE TQ Ý[ È© à$'(720oC) ï `
4©è 4^, È© à$'ÿ `4á TQ ÎW
ã( e$ (J9 @ e$@ þ5 h
¢(). oá ±Lmn1 Ò"4 >cF` mnã ï(Fig.
14) m hã1 WÛáE anode-off gasÕ5 TQ É1 m
n4©è ]@).
3-4. $
3 z; 2@ kv Å4 |4 2@
d (J9, Ø (J9, TQ
Ý[ È© d X$(Wd] ¼1 F N). Fig. 15 |4
24 @ d [1 ©4µ).
(J9 d (J9 $E ³(±L) d4
±L Ø *+E ² Ø1 ratio d4 \). TQ È©
Í° mn4 m㥠±Lã1 ä~ E split range
d 4 Ø (J9 d (J9 $E vJ\
ã( vJã 1/2)1 B4 (J9( 30% W©è m h
ã1 d4á 3 1 ¥5 d ).
(u ¼Ä 2-2-5E à@ ventfg (J@ ²/N O< í
ld© VE] @).
4.
f [ p LG-Caltex $h()E 94 IH
% 1 2`5 HYSYS (JE IH
C " m$1 kö&4 , C m$1 ¤4 3 1
[4µ). $``w kv ¤¥ m$ 9 :(u >Ê@ ¤¥
kv >( p m$¥ `£ e'4 ¢1 ½I N).
@ |4 *] m$ 9 1 O,4 o 24
E (J91 d 4 d 01 4µ
). (Ó (J9Z ¯X ý$( Q>4 ( $4 Pý
kö1 ¼Ä Y4µ). @ (J91 ¤$4 E |4
u (J91 ê áE kv V@ ¤¥
(J91 70% ï h4á |4 %Î4ù+© anode-off gas
Õ1 ê TQ @ É1 mn ×1 F N).
(J9 d T·( ¥5 JW E TQ È©
du N/² @ íld© ¼Ä VE] 4 CC d /
01 Y4 ( ¶5 1 §C d [
4µ).
f [ <m" T% va Ph¥ 2002
© Eë2Ê Êy [> ³ 4 (d8×1 i( MvD
÷).
y : mole fraction
F : Faraday constant [C/mole]
R : load (resistance) [kΩ]
λ : heat of vaporization of water [J/mole]
q : steam fraction
c : average specific heat [cal/g oC]
S : effective area of a unit cell [cm2]
n : No. of unit cells in stack
η : hydrogen utilization
i : current density [mA/cm2]
m : molar flow rate [mole/min]
a : anode
c : cathode
s : stack
w : cooling water
1. Blomen, L. and Mugerwa, M., Fuel Cell Systems, Kluwer Aca-
demic Pub, New York(1994).
Fig. 15. Suggested control scheme for the PAFC.
41 2 2003 4
50 kW 201
vel-
ing
W
2. Whitaker, R., “Investment in Volume Building: the ‘Virtuous Cycle’
in PAFC,”J. of Power Sources, 71, 71-74(1998).
3. Komei, K., Masakazu, M., Hiromasa, Y. and Hidetoshi, S., “PAFC
Operating Performance Verified by Japanese Gas Utilities,”J. of Power
Sources, 86, 298-301(2000).
4. LG-Caltex Oil Co. Ltd, “Research for Development of Stack & Oper-
ating Technology of 50 kW PAFC,” Ministry of Commerce, Industry and
Energy, 179-198(2000).
5. Kortbeek, P. J., Ruijter, J. A. F., van der Laag, P. C., Hagg, F. and
Barten, H., “A Dynamic Simulator for a 250 kW Class ER-MCFC
System,”J. of Power Sources, 71, 278-280(1998).
6. Yang, J. C., Seo, S. H., Park, Y. S., Seo, H. S., and Lee, H. J.,
“Development of a 50 kW PAFC Power Generation System,” Fuel
Cell Symposium, 9, 71-76(2002).
7. Yang, J. C., Park, Y. S., Seo, S. H., Lee, H. J. and Noh, J. S., “De
opment of a 50 kW PAFC Power Generation System,”J. of Power
Sources, 106, 68-75(2002).
8. Hou, K. and Hughes, R., “The Kinetics of Methane Steam Reform
over a Ni/-Al2O Catalyst,”Chem. Eng. Journal, 82, 311-328(2001).
9. Larminie, J. and Dicks, A., Fuel Cell Systems Explained, John Wiley
& Sons Ltd., Chichester(2000).
10. Lee, J. S., “Simulation and Consist of Control Algorithm for 50 k
PAFC,” a Master’s Thesis of Sogang University(2002).
11. Lee, K. S., Kim, J., Lee, J. S., “Modeling of stack,” Fuel Cell Sym-
posium, 8, 215-220(2001).
HWAHAK KONGHAK Vol. 41, No. 2, April, 2003