Fuel Cell System Modeling and Control for Vehicular Applications

Transcription

1 Fuel Cell System Modeling and Control for Vehicular Applications Donald J. Chmielewski Associate Professor Center for Electrochemical Science and Engineering Chicago, IL

2 City of Chicago and IIT Northwestern University Illinois Institute of Technology University of Chicago

3 City of Chicago and IIT Northwestern University Illinois Institute of Technology University of Chicago

4 Academics at IIT Engineering Architecture Psychology Science and Letters Business Law Industrial Design

5 Architecture at IIT Mies van der Rohe

6 Architecture at IIT Mies van der Rohe Helmut Jahn

7 Armour College of Engineering Biomedical Engineering Chemical & Biological Engineering Civil, Architectural & Environmental Engineering Electrical & Computer Engineering Mechanical, Materials & Aerospace Engineering

8 Engineering Alumni Paul Galvin Marvin Camras Martin Cooper

9 Engineering Alumni Paul Galvin Marvin Camras Martin Cooper Kenneth Bischoff Donald Othmer

10 Engineering Alumni Paul Galvin Marvin Camras Martin Cooper Kenneth Bischoff Donald Othmer Bernard Baker

11 Chemical & Biological Engineering Energy & Sustainability - Fuel Cells & Batteries - Fluidization and Gasification - Hybrid Systems Advanced Materials - Interfacial Phenomena & Colloids - Transport Phenomena in Complex Fluids - Biomaterials - Fuel Cell Materials - Nanotechnology Biological Engineering - Multiscale Modeling of Proteins - Biosensors & Hydrogels - Diabetes Modeling & Technology - Pharmaceutical Engineering Systems Engineering - Complex Systems Analysis - Advanced Process Control - Process Monitoring and Diagnosis

12 Fuel Cells and Batteries Jai Prakash - Electro-catalysis: material synthesis and characterization Vijay Ramani - Hybrid materials for PEMFC: hydration and degradation Satish Parulekar - Modeling of SOFC electrodes Donald Chmielewski - Modeling, design and control of fuel cell systems

13 Process Systems Engineering Chmielewski Lab Energy Systems Power Systems - Dry Gasification Oxy- Combustion DGOC Process - Control of Oxygen Enhanced Boilers - Oxygen as Energy Carrier Fuel Cell Systems - SOFC - Fuel Processors - PEMFC - Hybrid Vehicles Control Theory Profit Control - Chemical Processes - Inventory Planning - Smart Grid Operation - Water Resource Management - Hybrid Vehicles Market Responsive Control - Power Plant Dispatch - Building HVAC with Thermal Energy Storage

14 Technical Outline Start-up of a On-board Fuel Processor PEMFC Hydration Dynamics and Control Control and System Design for Hybrid Vehicles

15 PrOx1 PrOx PrOx3 WG1 WG WG3 WG4 Fuel Processor System at Argonne Water Air Fuel ATR Water Air

16 Fuel Processing Reactors Reformer Water- Gas Shift WGS Preferential Oxidation PrOx PEMFC Hydrocarbon Feed Large Hydrocarbons Cracked: CO levels down to ~ 10 ppm Low H to CO ratio Most CO converted to CO : ~ 1% CO remaining

17 Fuel Processing Reactors Reformer Water- Gas Shift WGS Preferential Oxidation PrOx PEMFC Hydrocarbon Feed Large Hydrocarbons Cracked: CO levels down to ~ 10 ppm Low H to CO ratio Most CO converted to CO : ~ 1% CO remaining

18 ATR Reactor Liquid water Vaporized gasoline, Steam Nozzle Hot air High Space Velocity GHSV ~ 50,000/h Catalyst bed Heater rod Thermocouple 7 mm Noble Metal Catalyst Metal wall thickness=1.7 mm 1 mm Rh on a Gd-CeO substrate. 1 mm Operating Temperature 96 mm ~ o C Air 5 C Heat exchanger

19 Reactor Model Axially Dependent, Nonlinear Dynamic Version, 0 s j g j g j c c c g j g k A x m N i i ij j g j s j g j c r M k 1, 0 ˆ 0 s g g c c c g g p g T T h A x T c m ˆ w s w w w w p w T T x h t T S c Mass Balances: Catalyst Phase: Gas Phase: Energy Balances: Gas Phase: n 1 i c Heat transfer to reactor wall,... 1 ˆ i i s g c c s w w w s ax e s s p s r H T T h T T x h x T x t T c Solid Phase: Reactor Wall:

20 Reactions within ATR Oxidation: C H m n/ 4 O mco n/ H m n O r k y 1 1 O Strongly exothermic C Steam Reforming: m n r CO H k mh O y C m 1 k Water Gas Shift: H a mco m n/ y H y C O m O CO H H Strongly endothermic r k ycoyho yco y H / K 3 3 e Papadias, et.al. 006, Ind. Eng. Chem. Res. Combined

21 Reactor Start-up: A Step Procedure Partial Oxidation Mode to quickly increase temperature Hydrocarbon Fuel Air PO Reactor ATR Mode for greater CO conversion Steam Hydrocarbon Fuel Air ATR Reactor

22 Molar fractions wet - Molar fractions wet - Steady-State Axial Profiles CPOX Mode: ATR Mode: CO H H CO HO HO CO Fuel 0.05 CO Dimensionless x-axis x/l O Fuel Dimensionless x-axis x/l

23 Temperature C Model Validation mm mm mm 00 Inlet temperature Time s Papadias, et.al. 006, Ind. Eng. Chem. Res.

24 Feedback Control

25 Hydrogen Flow, mol/min or CO, mol% Fuel Flow, g/min Steam Flow, g/min Temperature, o C Air Flow, g/min Load Change with PI Controller 50 Fuel 800 T, measured Steam Air Time, s Time, s H CO Time, s

26 Feed-forward plus Feedback Control

27 Hydrogen Flow, mol/min or CO, mol% Fuel Flow, g/min Steam Flow, g/min Temperature, o C Air Flow, g/min Load Change with FF Controller 50 Fuel Steam Time, s T, measured Air Time, s H CO Solid: C 7.3 H 14.8 Dotted: C 8 H Time, s

28 Conclusions from Classic Control Feedback Control Good performance for small load changes. Poor performance for large load changes. Feed-forward Control Good performance for large load changes Model mis-match a major concern

29 Nonlinear Model Predictive Control Level 1 Steady State Optimizer SSO u Level Nonlinear Dynamic Trajectory Optimizer Input &Output Reference Level 3 Model Predictive Control uk Level 4 PI PI PI ATR

30 Challenges to Model Predictive Control - Optimization based - Small sample intervals for feedback - Accurate model for feed-forward action

31 Applying Model Reduction Galerkin Approximation N j j s j s z t x t z T 1, N j j w j w z t x t z T 1, ˆ t Bq Ax x T w N w w s N s s x x x x x x x ], ;, [ 1 1 We arrive at the finite dimensional model

32 Comparison of Computational Effort Solution method CFD ROM1 Run-time, s Prediction Horizon is 180s Matlab with Core Duo CPU.33G Hz and 1G DDR RAM

33 Reduced Mass Balance Model w C m H n r a ~ O H H w C w K r n m z a e r z r z a e r z r ~ ~ r n m w M w M r n m n m H C H H H C z a e r z r / /, 1 O O g m O c M n m w k r m k A a g m O c c, 1

34 Comparison of Computational Effort Solution method CFD ROM1 ROM Run-time, s Prediction Horizon is 180s Matlab with Core Duo CPU.33G Hz and 1G DDR RAM

35 Solid Temperature, o C ATR Model Comparison 1000 mm Reduced CFD Time,s

36 Nonlinear Model Predictive Control Level 1 Steady State Optimizer SSO u Level Nonlinear Dynamic Trajectory Optimizer Input &Output Reference Level 3 Model Predictive Control uk Level 4 PI PI PI ATR

37 Flow rate, g/min or dm 3 /min Temperature, o C Inlet Temperature Disturbance Inputs Water Outputs NMPC Open-Loop Feedforward Air Fuel Time, s Time, s T in 0 C

38 Flow rate, g/min or dm 3 /min Temperature, o C Feedstock Model Mis-Match Inputs Water Outputs NMPC Open-Loop Feed-forward Air Fuel Time, s Time, s C 7.3 H 14.8 C 8 H 18

39 Technical Outline Start-up of a On-board Fuel Processor PEMFC Hydration Dynamics and Control Control and System Design for Hybrid Vehicles

40 Dynamic Model of PEMFC Cooling Air In Anode In H, H O Solid Material H H O Insulator Current Collector O N Jacket Exhaust Cathode In air Parameters based on 1 kw scale. Humidified hydrogen feed Anode Exhaust H O Cathode Exhaust Air cooling is assumed. Gas Diffusion Layers GDLs Catalyst Layers Polymer Membrane E cell

41 Dynamic Model of PEMFC Material Balances Energy Balances dc H an an H in an H H mem in V F C, F C r A dt dc an HO in an an an an an H O in an H O H O mem V F C, F C J A dt F C F C r J A in an an an H H O mem dc O ca ca O in ca O O mem in V F C, F C r A dt dc ca HO in ca ca ca ca ca H O in ca H O JH O V F C, F C dt F C F C r J A in ca ca ca O H O mem A mem dt ca in in UA Vca Fca Tca Fca Tca Tsol Tca dt C p dt an in in UA Van Fan Tan FanT an Tsol Tan dt C p dt jac in in UA Vjac FjacTjac FjacTjac Tsol Tjac dt C p dt C p Vsol UA Tca Tsol sol ca dt UA T T UA T T Q A sol jac jac sol an an sol gen mem ca an jac

42 Electrochemical Model E cell E ner E act E ohm E mt E ner E o 1 RT F RT F sol sol E act ln j / j o j o o ca C / o O C O PH P ln PH j o 1/ O O E E ohm mt IR 1 1 tmem j K RT F sol ln j F K L mt D ca GDL j mt L t j C L GDL ca O j

43 Hydration Model for MEA C mem J HO Jdiff Jdrag D z mem HO j F Anode Solid Material Current Collector In Cathode H, H O H Air in O H + H + C mem H O t D e C z mem H O Anode Exhaust H O H + H + H + H + H + H + N H O Cathode Exhaust Boundary Conditions MEA D D e e C z C mem H O mem H O z j F j F J J an H O ca H O 0 r H O 0 at at z 0 z m

44 Water Transport in the Membrane ELECTRO-OSMOTIC DRAG DIFFUSION

45 Concentration Profiles mem C H O m an C HO ˆ mem C o mem C H O 0 ca ˆ mem C C HO m mem C z HO Anode Gas GDL Membrane GDL Cathode Gas δ a δ m δ c

46 Power/Temperature Control P e sp Power Controller F c o, F E cell P e, j a o PEMFC T sol sp + - PI F jac T sol

47 Power/Temperature Control 0.5 Power Density watts/cm P e P e sp Time seconds

48 Power/Temperature Control

49 Power/Temperature Control! Water Content mem / mem Time seconds

50 Power/Temperature Control Power Density watts/cm P e P e sp Time seconds

51 Power/Temperature Control

52 Power/Temperature Control! Water Content mem / mem Time seconds

53 Manipulation of Hydration Profile mem, sp C HO P e sp T sol sp Power/ Temp Controller + - G c c a Fo, Fo E cell, F jac P e, j T sol u PEMFC mem C HO m! Water Content mem / mem Time seconds

54 Anode Bubbler Temperature Open Loop Test 11! Water Content o C86 o C

55 Solid Temperature Set-Point Open-Loop Tests 8! Water Content o 80 C85 o C

56 Combined Approach Water Content

57 Manipulation of Hydration Profile P e sp T sol sp Power/ Temp Controller + - G c c a Fo, Fo E cell, F jac P e, T sol j PEMFC C HO mem 8, CHO u m - Water Content

58 Most Frequent Question Power Density watts/cm P e P e sp Time seconds

59 Most Frequent Question Power Density watts/cm P e P e sp Transportation Applications?? Time seconds

60 Technical Outline Start-up of a On-board Fuel Processor PEMFC Hydration Dynamics and Control Control and System Design for Hybrid Vehicles

61 Hybrid System with DC-DC Converters i a i fc i afc i b i ab R a R b L a V fc FC k fc V b k b V a E b

62 DC-DC Converter Model DC-DC converter relations: V k V i i / a fc fc afc fc k fc i fc i afc Fuel cell V-I relation polarization curve: V fc f i fc V fc FC k fc V a Combined V-I relation: V k a fc f k i afc fc If fc fc fc fc afc E fc Va k fc k fcrfc polarization curve is V E i R, then i /

63 The Open-Loop Process k fc k bat Vehicle v veh

64 Vehicle Speed Control V fc V fc sp min max V fc sp v veh sp PI x PI k fc k bat Vehicle v veh

65 Vehicle Speed Control Simulation Power Profles Voltage Motor Speed motor [rad/s] Armature Fuel Cell Battery time, sec Battery Fuel Cell time, sec Vehicle Speed V speed [mph] V sp time, sec

66 Lesson from Reactor Control C A T sp + - PI F jacket sp + - PI Valve position CSTR F jacket T PI + - C A sp

67 Lesson from Reactor Control C A CSTR Valve position PI + - C A sp

68 Lesson from Reactor Control v veh v veh sp + - PI k bat Vehicle

69 Power Load Control P fc P fc sp - + PI V fc sp x FUEL CELL VOLTAGE CONTROLLER V fc k fc Vehicle P bat sp + - x PI k bat v veh P bat

70 Hybrid Power Load Control P fc P load sp - + PI V fc sp x FUEL CELL VOLTAGE CONTROLLER V fc k fc Vehicle P bat sp + - x PI k bat v veh P bat

71 Separation of Time-Scales i fc i afc i b R b i ab i a R a L a Armature Power Profles [W] Fuel Cell V fc FC K fc V b E b K b V a sp P load P mot sp - + PI V fc sp x P fc FUEL CELL VOLTAGE CONTROLLER V fc 0 Battery P bat sp + - x PI P bat k fc k bat Vehicle P mot time, sec

72 Vehicle Speed Control P fc v veh sp + - x PI P load sp - + PI V fc sp x FUEL CELL VOLTAGE CONTROLLER V fc k fc Vehicle P bat sp + - x PI k bat v veh P bat

73 Speed Control Simulation Power Profles [W] sp P load Armature Voltage [V] Battery Motor Speed [rad/sec] Battery Fuel Cell time, sec Armature Fuel Cell time, sec Vehicle Speed Vehicle Speed [mph] Vehicle Speed Request time, sec

74 Hybrid Fuel Cell Vehicle Double Storage Configuration Power Bus i arm i fc i afc i bat i abat i scap i ascap R arm Fuel Cell E fc DC-DC Converter R bat E bat DC-DC Converter R scap E scap DC-DC Converter E arm L arm w arm k fc k bat k scap

75 Supervisory Control P motor PI k fc Supervisory Controller P sp fc + - PI P sp bat + - PI P fc k bat P bat k scap Vehicle Power System P sp scap + - P scap

76 Disturbance Modeling High Level Controller sp P mot PI sp P fc + - PI sp P bat + - PI sp P scap + - k fc P fc k bat P bat k scap P scap Vehicle Power System

77 Power to Motor kw Speed mph Drive Cycle Characterization time sec time sec

78 Hybrid System Optimization min{ cˆ m cˆ m cˆ m } such that: fc fc bat bat sc sc - Operation within constraints limits - Motor power demands met - Supervisory controller embedded

79 Separation of Time Scales 15 SuperCap Power, kw timehr Battery Power, kw Fuel Cell PowerkW timehr timehr

80 Acknowledgements Students: Yongyou Hu ATR Kevin Lauzze PEMFC Syed K. Amed PEMFC and Hybrid Vehicle Collaborators: Shabbir Ahmed and Dennis Papadias ANL, ATR Herek Clack MMAE-IIT, ATR Said Al-Hallaj UIC, Hybrid Control Ali Emadi ECE-IIT, Hybrid Control Funding: IIT Graduate College and Armour College of Engineering Argonne National Laboratory National Science Foundation CBET