Issue 15

N.

Zuliani, Frattur

a ed Integrità St

rutturale, 15 (20

11) 29-34; DO

I: 10.3221/IGF-E

SIS.15.04

S T

ACK PERFO

RMANCE OP

ERATING W

ITH HYDR

OGEN

F

ig. 4 sho hydrogen fuel cell

ws the stac at 160°C. I [8] at the sam responding t ll voltage. A d increases: f e stack (27% less). could be exp auses a mark are lower rmance. RMANCE AN D REFORM ws the mea and the sim re 5% at 200 lower than rthermore, du pect regardin the entire s be made: e distribution e distribution ls exhibit the cm 2 , the cell

k polarizatio n the same fi e operating o a power de s expected st or example o less). At 0.5 lained referri ed stack temp at stack end

n curve and gure the pola conditions is nsity of 292 ack perform perating at 0 V power de ng to the stac erature non s. Increasing

the stack p rization curv included. Th mW/cm 2 . T ance is lower .6 V power nsity is 338 k temperatur uniformity (s stack load

ower density e and the po e stack has he maximum than single density is 221 mW/cm 2 for e distribution ee Fig. 8). A tends to de

variation w wer density v a nominal po reached sta cell perform mW/cm 2 fo the single fu : at low load s performanc crease temp

ith load ope ariation with wer of 365 W ck power ha ance. Perform r the single el cell and 2 s the heat di es depend on erature non

rating with p load for a si at 0.5 V m s been 433 W ance differe fuel cell and 92 mW/cm 2 spersion thro temperatur uniformity t

ure ngle ean at nce 162 for ugh e [1, hus

cell 0.4 dec mW the Th the 2], imp

voltage, cor 6 V mean ce reases as loa /cm 2 for th stack (14 % is behaviour end plates c cell voltages roving perfo

S T HY

ACK PERFO DROGEN AN

D VOLTAGE ATE FUELS

DISTRIBU

TION OPER

ATING WITH

F

for the stack fferences bet reformate o a single fu as load incre west voltage 2 and 400 m

ig. 5 sho hydrogen of fuels a

n cell voltag ulated reform mA/cm 2 an that with h e to the CO g the stack o tack. Fig. 6 s patterns are follows a p lowest volta number 1 rea

e and mean ate at 160°C d 9% at 400 ydrogen as poisoning ef peration is th hows the sta similar both arabolic patt ges; ch a very low

power den . Referring mA/cm 2 . Sta previously o fect, perform e voltage no ck voltage d for the hydro ern that is sim

sity variation to Tab. 1 per ck performan bserved in ance differen n-uniformity istribution a gen and refo ilar to that

with load formance di ce related to [7, 8] where ce increases , since the lo t 200 mA/cm

operating w ween the 2 ty peration are o el cell has b ase [17]. cell will limit A/cm 2 . Sev

ith pes nly een the eral

to inv An per obs

some extend estigated. Fu important as formance of ervation can stack voltag stack voltag Fig. 8; the ends cel at 400 mA/

rmate case; of the stack

 

temperature

profile show

n in

 

fuelled with r

voltage of 0

.326 V when

the stack is

eformate.

0.7

400

1.0

H2 - mean cell volt Sim. reformate - m H2 - power density Sim reformate - po

age ean cell voltage

350

0.9

wer density

0.6

300

0.8

250

0.7

[mW/cm 2 ]

0.5

200

V

[V]

0.6

150

H2 - 200 m Sim. reform H2 - 400 m Sim. reform

A/cm2 ate - 200 mA/cm2 A/cm2 ate - 400 mA/cm2

0.5

0.4

100

0.4

50

0.3

0

0.3

5

9

1 Cell n

3

17

21

25

1

0

200

400

600

800

umber

A/cm 2 ]

[m

Figure 5 : Mean oad. Stack mea reformat

cell voltage a n temperature e (H 2 56.35%,

nd power den 160°C. Fuels CO 0.5%, 43

sity variation w : H 2 and simul .15 % CO 2 ).

ith ated

S re 6 : Voltage d tack mean tem reformate

istribution at 2 perature 160 (H 2 56.35%, C

00 mA/cm 2 a °C. Fuels: H 2 a O 0.5%, 43.15

nd 400 mA/c nd simulated % CO 2 ).

m 2 .

Figu

l

32