Solar power station – an element of dispersed power system

Wroclaw Division of Electrotechnical Institute;Wroclaw University of Technology, Dep. of Electrical Eng.

Bolesław Mazurek

Solar power system

T-s Diagram of Rankine cycle

Theoretical and real characteristics of fuel cell

Vehicle mechanism

oxygen

oxygen in the middle ion H3O

hydrogen

H2O

H3O

PEM Fuel Cellreactions:

Cathode reaction:O2 + 4H+ + 4e- 2H2O

Anode reaction:2H2 4H+ + 4e-

Summary raction:2H2 + O2 2H2O

Our construction of PEMFC

V-I characteristics of IEL and commercial PEMFC

SOFC Fuel Cellreactions:

Cathode reaction:1/2O2 + 2e- O2-

Anode reactions:H2 + O2- H2O + 2e-

CO + O2- CO2 + 2e-

CH4 + 4O2- 2H2O + CO2 + 8e-

Summary reactions:H2 + 1/2O2 H2O

A

IR

F

UE

L

hydrogen

oxygen

Ptcathode

Ptanode

SOFC electrolyte

New electrolytes elaborated in

IEL/OW for SOFC application

Chemical formula Name

Bi2V0,75Cr0,25O5,25 - BIMEVOX

Bi2V0,9Sb0,1O5,4 - BIMEVOX

Bi2V0,9Co0,1O5,4 BICOVOX family

Bi2V0,875Ti0,125O5,4375 BIMEVOX family

Bi2V0,86Zn0,1O5,25 BIMEVOX family

Bi2V0,73Zn0,27O5,095 BIZNVOX.27

Bi2V0,9Cu0,1O5,35 BICUVOX.10

Bi4V2O11 BIVOX family

Bi4V1,9Co0,1O10,85 BIVOX family

Bi4V1,8Co0,2O10,7 BIVOX family

Bi2Co0,1V0,9O5,35 BIVOX family

(Bi0,95Zr0,05O1,525)0,8(YO1,5)0,2 stabilizowany -Bi2O3

Bi4V1,95Fe0,05O10,95 BIMEVOX family

Bi4V1,9 Fe 0,1O10,9 BIMEVOX family

Bi4V1,8Fe0,2O10,8 BIMEVOX family

Bi4V1,5Fe0,5O10,5 BIMEVOX family

Bi4V1,75Fe0,25O10,75 BIMEVOX family

Bi4V1,7Fe0,3O10,7 BIMEVOX family

(Bi0,95Zr0,05O1,525)0,85(YO1,5)0,15

(Bi0,98Zr0,02O1,51)0,85(YO1,5)0,15

(Bi0,90Zr0,10O1,55)0,85(YO1,5)0,15

(Bi0,90Zr0,10O1,55)0,8(YO1,5)0,2

Also investigation ofscandium stabilized zirconium oxide(e.g. ScSZ)

Ionic conductivity measurements

Fig.1 Diagram of the system for measurement of the ionic conductivity, DC four probe Wagner method.

Fig.2 Diagram of the test stand for measurement of the ionic conductivity, IS impedance spectroscopy method.

Typical Arhenius characteristics of electrolytes

Typical impedance spectra of electrolyte

350oC

0,0E+00

5,0E+04

1,0E+05

1,5E+05

2,0E+05

2,5E+05

3,0E+05

3,5E+05

4,0E+05

4,5E+05

5,0E+05

0,0E+00 2,0E+05 4,0E+05 6,0E+05 8,0E+05 1,0E+06 1,2E+06 1,4E+06R[ ]

-X[

]

450oC

0,0E+00

1,0E+04

2,0E+04

3,0E+04

4,0E+04

5,0E+04

0,0E+00 2,0E+04 4,0E+04 6,0E+04 8,0E+04 1,0E+05 1,2E+05 1,4E+05

R []

-X [

]550oC

0,0E+00

1,0E+03

2,0E+03

3,0E+03

4,0E+03

5,0E+03

6,0E+03

7,0E+03

8,0E+03

0,0E+00 5,0E+03 1,0E+04 1,5E+04 2,0E+04 2,5E+04

R []

-X [

]

- in reducing atmosphere - in oxide

Our tubular SOFC

0

100

200

300

400

500

600

700

800

0 5 10 15 20 25current density [mA/cm2]

V [

mV

]

605 C

703 C

803 C

853 C

902 C

952 C

SOFC V-I characteristics in the function of temperature

Temperature[oC]

Resistance ScSZ[]

200 16000000

250 1700000

350 35000

450 1870

550 27

600 10

700 10

800 10

Electrolyte resistance ScSZ

Designe of fuel cell test stand

Our fuel cell test stand

PerformanceDC voltage 10 VCurrent 50 ANominal current density 500 mA/cm² at 0.7 V (cell)Nominal power rating 500 WStack efficiency >40% at 500 WCell number 16, effective area of each cell 100 cm²

Air requirementNominal flow 35 SLPMUse efficiency 40% at 500 WHumidity 70-90% RHInlet pressure 1.0-2.5 bar

Operating conditionsTemperature 70-80 °CPressure 1.0-2.5 barCoolant DI waterCoolant Flow 3.5 l/min.PhysicalWidth 17 cm Height 11 cm Depth 20 cm Weight 12 kg

Hydrogen fuel requirementH2 Commercial grade (CO < 1ppm)Nominal flow 7.5 SLPMHumidity 70-95% RHInlet pressure 1.0-2.5 bar

PEMFC stack specification

Characteristic of commercial 500 W PEM stack

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