Frano Barbir Pictorial Resume. energy partners

Transcription

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2 Frano Barbir Pictorial Resume energy partners

3 Diagnostic(s) noun the art or practice of diagnosis Diagnosis noun Investigation or analysis of the cause or nature of a condition, situation or problem

4 Diagnostics in fuel cell development process

5 requirements design Knowledge: materials processes interactions model fabricate Should it work? test Does it work? diagnostics

6 Diagnostics in fuel cell development process Diagnostics in control development process

7 Diagnostics in fuel cell development process Diagnostics in control development process Diagnostics in operation

8 disturbances control element manipulated variable fuel cell process variable controller output signal measured value controller error set point measured process variable signal measurement sensor/ transmitter

9 Observe (voltage/current, pressure drop, temperature) 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,

10 Observe (voltage/current, pressure drop, temperature) Change a parameter and compare

11 First fuel cell law: One cannot change only one parameter in a fuel cell change of one parameter causes a change in at least two other parameters, and at least one of them has an opposite effect of the one expected to be seen. F. Barbir, PEM Fuel Cells Theory and Practice, Elsevier/Academic Press, 2005

12 Fuel cells: Problems at different scales m mm m nm km 12.7 km 12.7 m 12.7 mm

13 Observe (voltage/current, pressure drop, temperature) Change a parameter and compare Disturb and observe Small disturbances Large disturbances (exaggerate or accelerate)

14 disturbances control element(s) manipulated variable(s) fuel cell process variable(s) controller output signal(s) controller controller action signal diagnostics measured values diagnosis desired/expected state of health

15 Diagnostics in fuel cell development process Diagnostics in control development process Diagnostics in operation Post mortem diagnostics

16 Online Offline Post mortem

17 Electrochemical techniques Polarization curve Current interruption Electrochemical Impedance Spectroscopy Cyclic Voltammetry CO Stripping Voltammetry Linear Sweep Voltammetry Species Distribution Mapping Pressure Drop Measurements Gas Composition Analysis Neutron Imaging Magnetic Resonance Imaging X-ray Imaging Optically Transparent Fuel Cells Embedded Sensors Current Distribution Mapping Partial MEA Segmented Cells Temperature Distribution Mapping IR Transparent Fuel Cells Embedded Sensors

18 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

19 cell potential (V) theoretical (ideal) voltage activation losses resistance losses resulting V vs. i curve mass transport losses current density (ma/cm²)

20 cell potential (V) higher resistance drying? mass transport problems flooding? normal polarization curve current density (ma/cm²) hgher activation losses

21 Data should be taken at multiple current or voltage points. Typical points would be open circuit and 5 or 6 points between 600 mv/cell and 850 mv/cell, 15 minutes dwell at each point The data from the last five (5) minutes should be averaged and then plotted as average current versus average voltage. Protocol on Fuel Cell Components Testing

22 Polarization curve sweep

23 Qiangu Yan, J. Power Sources, Vol 161, 2006, pp

24 Cell Voltage/Differential Pressure Static Feed UNIGEN Cycle Test (Total 8/1/03 3:00 PM cycles) Electrolysis: ASF; Fuel Cell: ASF > 100 LEO cycles 160 F, psig Fuel Cell 40 min Electrolysis 60 min Elapsed Time (hr) Presented at IECEC, Portsmouth, VA, August 12, 2003

25 M. Weiland, Int. J. Hydrogen Energy, 2012, in print

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27 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

28 c e ll p o te n tia l ( V ) current density (ma/cm²) Polarization curve at cell temperature 80 C anode/cathode humidifier temperatures 80/60 C hydrogen/air, 30 psig, H2 stoich 1.5, air stoich 5.0

29 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

30 Source: T.P. Ralph and M.P. Hogarth, Platinum Metals Review, Vol. 46, No. 1, pp. 3-14, 2002

31 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

32 Current interrupt method for measurement of fuel cell resistance Fuel cell Load Digital osciloscope A voltage OCV Slow rise to OCV V act Cell voltage before current interrupt Immediate rise in voltage, V R Time of current interrupt time

33 Current interrupt method for measurement of fuel cell resistance extrapolated straight lines OCV discrete points voltage ringing effect Cell voltage before current interrupt Immediate rise in voltage, V R Time of current interrupt time

34 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

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38 Nyquist and Bode plots

39 R HF Resistance

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44 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

45 Cell Potential (Volts), Resistance (miliohm-cm 2 ), Pressure Drop(10 kpa) Temperature ( o C) Cell Voltage Stack Temperature Pressure Drop Humidification Temperature Resistance Time (seconds)

46 Cell Potential (Volts), Resistance (miliohm-cm 2 ), Pressure Drop (10 kpa) Temperature ( o C) Stack Temperature Humidification Temperature Cell Voltage Pressure Drop Resistance Time (seconds)

47 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

48 S.J.C. Cleghorn, C.R. Derouin, M.S. Wilson, and S. Gottesfeld, A Printed Circuit Board Approach to Measuring Current Distribution in a Fuel Cell, J. Appl. Electrochem., 1997

49 local current density measurement dynamic > 2000 measurement /s L o k a l e M e s s u n g e n local temperature measurement local electrochemical impedance spectroscopy (EIS) 4 mm

50 D. Derteisen et al., Int. J. Hydrogen Energy, Vol 37, 2012, pp

51 D. Derteisen et al., Int. J. Hydrogen Energy, Vol 37, 2012, pp

52 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

53 ir camera

54 Temperature Mapping with ir Camera

55 smallest sensor on the market Sensirion SHT 71

56 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

57 Interdigitated Flow Field Straight Channels X Liu, et al. Water flooding and twophase flow in cathode channels of proton exchange membrane fuel cells, Journal of Power Sources,

58 D. Lee, J. Bae, Visualization of flooding in a single cell and stacks by using a newlydesigned transparent PEMFC International Journal of Hydrogen Energy, Vol. 37, No.1, 2012, pp

59 S Basu et al., J Power Sources, Vol 162, 2006, pp

60 K Takada et al. J. Power Sources, Vol 196, 2011, Pages Inukai, J. et al. Direct Visualization of Oxygen Distribution in Operating Fuel Cells. Angew. Chem. Int. Ed. 47, (2008).

61 Polarization curve Polarization curve hysteresis Comparative polarization curves Current interrupt AC impedance spectroscopy Pressure drop Current density mapping Temperature mapping Flow visualization Neutron/X-Ray imaging

62 Real time detection of liquid water inside an operating fuel cell

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64 at Penn State University A. Turhan, K. Heller, J.S. Brenizer and M.M. Mench, Passive control of liquid water storage and distribution in a PEFC through flow-field design, Journal of Power Sources 180 (2) (2008), pp

65 H. Markötter et al., Int. J. Hydrogen Energy, Vol 37, 2012, pp

66 P. Deevanhxay, Electrochemistry Comm.,

67 Conclusions Diagnostics important aspect of fuel cell R&D Limited number of diagnostic methods applicable for fuel cell control purposes Definition of optimum performance must include life time In order to achieve optimum performance diagnostics is crucial for prognostics and health management

68 More information about PEM fuel cells: Frano Barbir PEM Fuel Cells: Theory and Practice Elsevier/Academic Press, 2005 ISBN PEM Fuel Cells: Theory and Practice Written as a textbook for engineering students. Used at hundreds of universities In U.S., China, India, Korea, Iran, Germany, Croatia New updated edition coming out 2012! Available from: