Brayton Energy: Fuel Cell History - ARPA-E | Changing · PDF file · 2017-02-14Brayton Energy: Fuel Cell History ... turbine compressor SOFC 3 497F 307F ... o 25 to 70 amp current

Brayton Energy: Fuel Cell History

NREC/IR microturbine PSOFC

Gas Turbine Design and Manufacturing Compact Heat Exchanger Design and Manufacturing

ARPA-E HYBRID SYSTEMS WORKSHOP JANUARY 26-27, 2017

By Jim Kesseli [email protected]

System Integration

Brayton Energy Advanced Hybrid Fuel Cell Project with Siemens & Arctic Research/NETL/CTC (2004-2007)

1. Detailed system performance modeling, optimization, and LCOE

• Systematic Trades studies focused on lowering the cost of fuel cell systems.

• 6 cycles analyzed 2 MSFC 4 SOFC

•SOFC Hybrids showed the most potential

(lowest LCOE, highest efficiency)

2. Design of compact 850C heat exchangers

Four SOFC Hybrids Analyzed for Siemens-Westinghouse Arctic Energy Lab at U. Alaska

227F

1037F 59F

325F

1517F

76F

1145F

Unpressurized SOFC / Subatmospheric Turbine

012

4

5

67

8

compressorturbine generator

SOFC

3

837F

1512F

59F

827F

Turbocharged SOFC

01

2

4

5

compressorturbine

SOFC

3

497F

307F

1396F

1517F 1025F 59F

Unpressurized SOFC / Indirect-Fired Turbine

01

2

4

56

7

compressorturbine generator

SOFC

Valve is closed for this study

(open for supplemental firing)

(825 C)

429F

1042F

307F

1517F

59F

1123F

Pressurized SOFC

01

2

3

4

5

6

generatorturbine compressor

SOFC

3 4

65

Schematic for Proposed Intercooled Recuperated (ICR) Cycle Hybrid co-fired PSOFC

Variable-geometry nozzle

@ Station 7

5

9

HPTHPC ML2

LPTLPC

1

2a

ML1

FPT GENML30

2b

3

4

6

7

8

RECUP

10

SOFCThree degree of freedom system

1. Fuel throttle

2. VAN

3. PT speed

• Operate without

combustor firing, for

best efficiency, low

power.

• Co-fire combustor to

magnify power, load

follow, and

improved economics

Also studied SOFC Reheat cycle

Ceramic turbine, high firing temp gas turbine

ICR350 – Vehicular and stationary gas turbine

5

Peak electrical efficiency 42%, fired at 1100 C, 2000F

This ICR engine formed the basis for hybrid SOFC modeling.

SOFC Idealized Thermal Model

TAIR

TFUEL

COMBUSTOR

PREHEAT HX

1000CANODE

CATHODE

anode recirculation

TC1 1000C

825C @ DP

TCOMB

module control volume

stack control volume

TIT

7

Summary of Fired/Unfired Operating Parameters

fired unfired

TIT 2000F 1567F

Nozzle Setting 100% 70%

Airflow (kg/s) 0.83 0.31

PRSTACK 14.3 5.2

Engine Power (kWe) 248.3 46.8 (531%)

SOFC Power (kWe) 197.6 149.1 (133%)

SOFC Effy (LHV) 36.8% 48.9%

System Power (kWe) 445.9 195.9 (228%)

System Effy (LHV) 52.8% 64.2%

SOFC Current (amps) 439035 249394

Cell Voltage (V) 0.500 0.664

note: SOFC power & efficiency are net electric

after 90% inverter

Normalized costs:

Hybrid PSOFC at

700ma/cm2

Std atm. SOFC at

400ma/cm2

SOFC $/kW 3429 6000ICR GT $/kW 500

Net $/kWe 1798

Power density, ma/cm2 700 400

Fuel (low pressure natural gas)

Atmospheric SOFCGENSET: 4 to 10

kWe Hybrid SOFC

• Residential net

metering power

• ηe ~ 66%

• ηchp = 84% (1 kW-

thermal)

1

Siemens Westinghouse SOFC Hybrid (220 Kwe)

Courtesy Siemens Stationary Fuel Cells

2

Challenges

• Complex Balance-of-plant

• Turbine airflow match/mismatch with Fuel Cell requirements

• Low turbine inlet temperature

• Higher capital cost

• Operational complexity (higher risk to damage the fuel cell stack)

Siemens Westinghouse SOFC Hybrid System

Successes

• World’s first demonstration of a Fuel Cell/Micro Turbine Generator hybrid power system

• Successfully demonstrated startup-stable operation, and orderly shutdown

• ~3,000 hrs operation

• Electrical efficiency ~53% LHV (Potential for higher system efficiency)

• Reduced emissions (NOx and SOx)

Jack Brouwer, Ph.D.

Associate Director

2017

Dynamics of Hybrid Fuel Cell Systems

for: ARPA-E Workshop, Washington DC

© Advanced Power and Energy Program 20172/13

1

1.5

2

2.5

3

3.5

4

4.5

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2

Normalized Flow

Pre

ss

ure

Ra

tio 0.60

0.70

0.80

0.90

1.00

System

Normalized

RPMSurg

e Lin

e

1

1.5

2

2.5

3

3.5

4

4.5

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2

Normalized Flow

Pre

ss

ure

Ra

tio 0.60

0.70

0.80

0.90

1.00

System

Normalized

RPM

1

1.5

2

2.5

3

3.5

4

4.5

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2

Normalized Flow

Pre

ss

ure

Ra

tio 0.60

0.70

0.80

0.90

1.00

System

Normalized

RPMSurg

e Lin

e

Integrated Fuel Cell System Dynamics

0 50000 100000 150000 200000160

162

164

166

168

170

FC

Po

we

r [k

W]

Time [sec]

Experiment

Model

FC Power

Jan 2001

0

20

40

60

80

100

120

140

160

180

200

Jan-7 Jan-9 Jan-11 Jan-13 Jan-15 Jan-17 Jan-19 Jan-21

Day

Po

we

r [k

W]

0

5

10

15

20

25

30

35

40

45

50

Co

mp

. in

let

Te

mp

. [C

]

http://www.fuelcellenergy.com/index.php

http://www.fuelcellenergy.com/index.php

http://www.sce.com/sc3/

http://www.sce.com/sc3/


Dynamic Simulation: 220kW SOFC/GT System

SOFC Power Experimental and Model Comparison

for the 220 kW SOFC/GT Hybrid

140

145

150

155

160

165

170

175

180

0 20000 40000 60000 80000 100000 120000 140000 160000

Time (sec)

SO

FC

Po

we

r (k

W)

an

d F

ue

l F

low

SL

PM

*(0

.30

)

0

5

10

15

20

25

30

35

Va

lve P

erc

en

t O

pe

n

Model SOFC Power

Experimenta SOFC Power

SOFC Fuel Flow

Recuperator Bypass Valve

SOFC Bypass Valve

Experimental SOFC Power


Air

Motor

SOFC

Blower

Oxid-

izer

Oxid-

izer

Refor-

mer

Heat

Exch.

Fuel

+ H2O

Exit

Heat

Exch.Steam

Prep.

How Can We Do It?

Integrated Stand-Alone SOFC system

• Manipulate:o Fuel flow

o Blower power

o Bypass valve

• Control:o System power

o Peak SOFC temperature

o SOFC temperature profile

• Perturbation:o 25 to 70 amp current increase with PEN temperature feedback

Mueller, F., Jabbari, F., Brouwer, J., Journal of Power Sources, Vol. 187, Iss. 2, pp. 452-460, 2009


PE

N

Te

mp

(K

)R

efo

rme

r

Tem

p (

K)

Time (s)

Time (s)

How Can We Do It?

Integrated SOFC system

25 to 70 ampcurrent increaseperturbation

Control actions:

© National Fuel Cell Research Center, 2011



Initial 0-s Peak 874s Final 50ksTransition 1050s

PE

N T

em

p (

K)

Curr

ent (A

)

How Can We Do It?

Integrated SOFC system - 25 to 70 amp current increase with PEN temperature feedback



Dynamic Poly-Generation Analyses

0 0.2 0.4 0.6 0.8 10

250

500

750

1000

Po

wer

[kW

]

0 0.2 0.4 0.6 0.8 10

20

40

H2 in

Tan

k [

kg

]

12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM0.5

1

1.5

2

2.5

3

3.5

H2/C

O o

ut

of

co

llecto

r[g

/s]

H2

CO

Can a Tri-Generation System Respond to Fueling, Full Tank?

• Diurnal dynamic operation of SOFC

• Hydrogen tank fills forcing end of tri-generation

• Control of system temperatures during transient is possible

12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM950

1000

1050

1100

1150

1200

1250

1300

Tem

p [

K]

Tan,in

Tca,in

Tca,out

Tan,out

Shaffer, B.P, and Brouwer, J. J. Fuel Cell Sci. Technol., Vol 9, p. 041012 ff., 2012


1-D Model Integration into Systems Analysis

Catalytic hydro-gasifier IGFC system

HP SOFC & HeatExchange System

(1-D, 0.8V, 73% mf)

Li, et al., Journal of Power Sources, Vol. 195, Iss. 17, pp. 5707-5718, 2010.


IGFC Performance Comparison

Item 0-D Model 1-D Single Stage Counter-flow SOFC

Coal energy input 1,397 GJ/h (HHV) 1,397 GJ/h (HHV)

SOFC operation pressure 10 atm 10 atm

Gross power output

SOFC electrical power 247.8 MW 247.3 MW

Cathode exhaust expander 63.4 MW 178.6 MW ↑

Steam turbine 2.6 MW 1.9 MW

Syngas reactor/expander topping cycle 9.3 MW 7.6 MW

Total gross power generated 323.3 MW 435.6 MW ↑

Auxiliary power consumption (incomplete list)

ASU 2,186 kW 2,186 kW

SOFC air compressor/blower 66,906 kW 242,499 kW ↑↑↑

Recycled H2 compressor 8,235 kW 8,283 kW

Total internal power consumption and losses

84.7 MW 260.5 MW ↑↑↑

Net electric power 238.6 MW 175.1 MW ↓↓↓

Overall thermal efficiency 61.5% (HHV) 45.1% (HHV) ↓↓↓

Li, M., Rao, A.D., Brouwer, J., and Samuelsen, Journal of Power Sources, Vol.195, Iss. 17, pp. 5707-5718, 2010.


Strategy for Mitigating High DT Challenge

• Cascade SOFC stacks

Overall Uf = 0.727Ua = 0.455

Air in650°C

Fuel in650°C

Fuel out671°C

Uf = 0.70

Ua = 0.15

Air addition330°C

Air713°C

Fuel in650°C

Fuel out689°C

Uf = 0.73

Ua = 0.16

Air addition330°C

Air732°C

Fuel in650°C

Fuel out704°C

Uf = 0.73

Ua=0.17

Air addition330°C

Air742°C

Fuel in650°C

Fuel out719°C

Uf = 0.74

Ua = 0.17

Air out753°C



IGFC Performance Comparison

Item 0-D Model 1-D Cascading Counter-flow SOFCs

Coal energy input 1,397 GJ/h (HHV) 1,397 GJ/h (HHV)

SOFC operation pressure 10 atm 10 atm

Gross power output

SOFC electrical power 247.8 MW 247.8 MW

Cathode exhaust expander 63.4 MW 72.1 MW ↑

Steam turbine 2.6 MW 2.7 MW

Syngas reactor/expander topping cycle 9.3 MW 7.6 MW

Total gross power generated 323.3 MW 330.4 MW ↑

Auxiliary power consumption (incomplete list)

ASU 2,186 kW 2,186 kW

SOFC air compressor/blower 66,906 kW 84,748 kW ↑

Recycled H2 compressor 8,235 kW 9,792 kW ↑

Total internal power consumption and losses

84.7 MW 104.3 MW ↑

Net electric power 238.6 MW 226.1 MW ↓

Overall thermal efficiency 61.5% (HHV) 58.2% (HHV) ↓



Dynamics to Complement Loads/Renewables

McLarty, D. and Brouwer, J., Journal of Power Sources, Vol. 254, pp. 126-136, 2014.

Dynamics to Complement Loads/Renewables

• 10% & 20% load-shed 30-100% diurnal load-following

McLarty, D. and Brouwer, J., Journal of Power Sources, Vol. 254, pp. 126-136, 2014.


Backup Slides


Sample Dynamic Conservation Equations

out

NinNin

outN

out

OHOHinOHin

outOH

out

COCOinCOin

outCO

out

HHinHin

outH

outRinout

out

outout

N

dt

VCdXN

X

N

dt

VCdRXN

X

N

dt

VCdRXN

X

N

dt

VCdRXN

X

dt

VCdNNN

RT

PC

)()(

)(

)()(

)(

)()(

)(

)()(

)(

)(

22

2

222

2

222

2

222

2

R+N-N=dt

dCV iii

i

outletinlet

)ii/-(1nF

TR-=L L

uC ln

F-AP-AP=dt

vdV soutletoutletinletinlet

)(

]][[

][]][[ln

,22

2/1

,2

2/1

22

aCOOH

cCOOHu

yy

Pyyy

nF

TRE=E

)i(i/Fn

TR=L o

uA ln

PP=P ac ,

ACR LLLE=Vcell

Species Conservation Sample Mass Conservation Equations

Momentum Conservation

Nernst Equation

Electrochemical Losses

Cell Voltage

iR=L cellR

Roberts, R., Mason, J., Jabbari, F., Brouwer, J., Samuelsen, S., Liese, E. and Gemmen, R., ASME Paper Number 2003-GT-38774, 2003.


Sample Dynamic Simulation Module Geometries

• Planar SOFC with 10 Discrete Computational Nodeso Anode Gas, Cathode Gas, Cell EEA, Separator Plates

• Reformer Module with 5 Discrete Computational Nodeso Anode Off-Gas Recycle, Fuel Mix, Combustor HX, Catalyst Bed

10 NODES

REFORMEDFUEL

CATHODE GAS

CELL EEA SEPERATOR PLATE

5 NODES

NATURALGAS

EXHAUST

STEAM /DEPLETED FUEL

REFORMATE

FC EXHAUST

Adiabatic Mixing VolumeCatalyst Bed


How Can We Do It?

Hybrid SOFC/GT System

• Manipulate:o Recirc. blower power

o Fuel flow

o Air preheat bypass valve

o SOFC air bypass valve

• Control:o System power

o Peak SOFC temperature

o SOFC temperature gradient

o Oxidizer temperature

• Perturbation:o Sudden decrease from 100%

to 50% full powerMcLarty, D.F., Samuelsen, S., and Brouwer, J. ASME Paper FC2010-33328, June, 2010


How Can We Do It?

Hybrid SOFC/GT System

• Met sudden decreasein power demand

• Kept SOFC peaktemperature < 1073 K during transient

• Kept SOFC temperaturegradient < 150 Kduring transient

McLarty, D.F., Samuelsen, S., and Brouwer, J. ASME Paper FC2010-33328, June, 2010


Sample Model Results: Syngas (1/3)

co-flow species distribution

counter-flow species distribution

fuel molar composition:26.26% H2, 17.1% CH4, 2.94% CO, 4.36% CO2, 49.34% H2O

adiabatic, atmospheric operation 85% fuel utilization, 14.3% air utilization


Sample Model Results: Syngas (2/3)

co-flow temperature counter-flow temperature




Sample Model Results (3/3)

co-flow

electrochemical performance

counter-flow

electrochemical performance




Quasi-3D cross-flow planar SOFC model – sample results

plots of cross flow planar SOFC PEN temperature and current density distributions

operated on syngas containing ~17 vol.% CH4 Uf = 85%, Ua = 14.7%

Extend to Quasi-3D Cross-flow Planar SOFC


Planar SOFC Model Geometry

Quasi-2D co/counter flow planar SOFC model

Li, M., Powers, J.D., and Brouwer, J., Journal of Fuel Cell Science and Technology, Vol. 7, pp. 041017-1-12, 2010


Key Simplifications & Assumptions

• Steady state model

• Resolve gradients in primary flow direction

• 4 separate temperatures resolved in each node • Positive electrode-electrolyte-negative electrode (PEN) structure

• interconnect

• fuel flow

• air flow

• H2 electrochemical oxidation only (CO oxidized through water-gas shift reaction)

• Water-gas shift reaction is always in equilibrium

• Methane reformation is controlled by local chemical kinetics

• External heat loss is by radiation heat transfer to vessel only

• Large Peclet number, thus the effect of axial heat conduction in gas phases is negligible Li, M., Powers, J.D., and Brouwer, J., Journal of Fuel Cell

Science and Technology, Vol. 7, pp. 041017-1-12, 2010


Numerical Scheme

Li, M., Powers, J.D., and Brouwer, J., Journal of Fuel Cell Science and Technology, Vol. 7, pp. 041017-1-12, 2010

PEN

PSR PSR PSR

PSR PSR PSR


1-D counter-flow SOFC model in integrated IGFC analysis

• Peak temperatures move to SOFC interior

• Inlet & outlet temperatures no longer represent peak DT

• Outlet fuel/air temperatures are decreased – disabling downstream heat use

• Air flow required for ∆Tmax=200°C is 4X that of 0-D model

Challenges Identified: 0-D vs. 1-D

fuel out (650 + 200) °C

air out (650 + 200) °C

fuel in650 °C

air in650 °C

fuel out (650 + 40) °C

air out (650 + 70) °C

fuel in650 °C

air in650 °C

Ultra-Clean | Efficient | Reliable Power

Hossein Ghezel-Ayagh

ARPA-E Workshop

January 27, 2017

Hybrid System Experience at FCE

Process Flow Diagram of DFC/T Power Plant

Operating pressures of fuel cell and turbine are independent

Turbine integration increases overall efficiency by 20-30%2

GenC

Anode

Cathode

LTR

T

Air

Out

Fuel Cell Sub-System

Gas Turbine Sub-System

Natural Gas

Water

Humidifier

AGO

HTR

Direct FuelCell Stack Module

• A 250 kW DFC stack module was utilized in the

subMW DFC/T Power Plant

3

• Compression ratio of ~ 3 - 4

• Mechanical Connections:

> Compressor exit port and turbine

inlet port for integration with fuel cell

system

• Range of air flows suitable for fuel

cell stack operation (0.8-1.0

lbs/sec)

• Capability to control air flows with

load (Speed Control)

• Microturbine’s controller modifiable

for integration with fuel cell control

system

• Single Shaft Design

Integrated Capstone

C60 Microturbine

Capstone Microturbine Features

4

Alpha Unit Factory Test

DFC®/T achieved a net efficiency

of 58% during the factory tests

• Tests by an independent firm indicated California Air Resources Board’s

(CARB) 2007 emissions standards for NOx and VOC were met.

Billings Clinic, Billings, MT

Completed operation at host site >8000

Achieved availability of >87% in producing power

Alpha Unit at Montana Test Site

6

Documents

Brayton Energy: Fuel Cell History - ARPA-E | Changing · PDF file · 2017-02-14Brayton Energy: Fuel Cell History ... turbine compressor SOFC 3 497F 307F ... o 25 to 70 amp current