update on ammonia engine combustion using direct fuel ......• fuel mixing and storage at high...
TRANSCRIPT
Department of Mechanical Engineering, Iowa State University 1
Update on Ammonia Engine Combustion Using Direct Fuel Injection
Christopher Gross, George Zacharakis-Jutz Song-Charng Kong
Department of Mechanical Engineering Iowa State University
Acknowledgements: Iowa Energy Center; Norm Olson Robert Bosch; National Instruments
Department of Mechanical Engineering, Iowa State University 2
Thermodynamics/Chemistry
• Stoichiometric chemical reaction
3 2 2 2 20.75 ( 3.76 ) 1.5 3.32NH O N H O N+ ⋅ + ⋅ → ⋅ + ⋅
Fuel Molecule Boiling Point (°C) (Air/Fuel)s
Latent Heat
(kJ/kg)
Energy Content
(MJ/kg-fuel)
Energy Content (MJ/kg-
stoichiometric mixture)
Methanol CH3OH 64.7 6.435 1203 20 2.6900
Ethanol C2H5OH 78.4 8.953 850 26.9 2.7027
Gasoline C7H17 --- 15.291 310 44 2.5781
Diesel C14.4H24.9 --- 14.3217 230 42.38 2.7660
Ammonia NH3 –33.5 6.0456 1371 18.6103 2.6414
Department of Mechanical Engineering, Iowa State University 3
Approaches
• CI engine operation • Port induction of gaseous ammonia, ignited by directly
injected diesel/biodiesel fuel • Achieved a wide range of load and speed conditions
• Direct injection of liquid ammonia/DME mixtures • To be presented
• SI engine operation • Direct injection of gaseous ammonia, enhanced by gasoline
combustion • On-going (to be presented)
Department of Mechanical Engineering, Iowa State University
NH3/DME
• Use direct liquid fuel injection • Confine combustion mixture near the center • To reduce exhaust ammonia emissions
• Dimethyl ether (CH3-O-CH3) as ignition source • Fuel mixing and storage at high pressure • New fuel injection system – without fuel return
• Injection pump, injector, electronic control
• Various NH3/DME ratios
4
Fuel injector
Department of Mechanical Engineering, Iowa State University
Engine Setup
• Yanmar diesel engine (L70V, 320 c.c.) • Rated power at 6.26 hp at 3,480 rpm
• Developed new fuel injection and engine control systems • Bosch GDI type injector (up to 200 bar injection pressure)
Department of Mechanical Engineering, Iowa State University
Setup • Mixing and storage of ammonia/DME at high pressure • Exhaust emissions measurements
• Horiba MEXA-7100DEGR (CO2, CO, O2, HC) • Horiba 1170NX (NOx, NH3) • AVL Smoke Meter (PM)
Fuel mixing system
Emissions analyzers
Department of Mechanical Engineering, Iowa State University
0
1
2
3
4
5
6
7
2200 2400 2600 2800 3000 3200 3400 3600
Pow
er [H
P]
Engine Speed [RPM]
Maximum Power Output utilizing different Fuels
Diesel (baseline)
100% DME
20%NH3-80%DME
40%NH3-60%DME
• Challenges • Latent heat • Flame speed
• Low to medium loads at various speeds
Hea
t of
Vapo
riza
tion
Flame Speed
Diesel Fuel
Operating Range
Department of Mechanical Engineering, Iowa State University
Mode Engine Speed (rpm) Engine Power (kW) Engine Torque (Nm) 5 2548 1.74 6.61
7 2548 0.87 3.31
9 2895 1.05 3.52
11 3243 1.12 3.34
20 2200 1.47 6.47
21 2200 0.74 3.24
Test Conditions
Fuel SOI (btdc) P_inj T_intake air 100%DME 0 ~ 30 150 bar 30 C 20%NH3-80%DME 5 ~ 35 150 bar 60 C 40%NH3-60%DME 15 ~ 40 180 bar 80 C 60%NH3-40%DME 140 ~ 180 205 bar 90 C
Results will be presented first
Department of Mechanical Engineering, Iowa State University
0
5
10
15
20
25
-10
0
10
20
30
40
50
60
70
-75 -60 -45 -30 -15 0 15 30 45 60 75
HR
R (J
/deg
)
Cyl
inde
r Pre
ssur
e (b
ar)
Crank Angle (deg)
100%DME20%NH3-80%DME40%NH3-60%DME
Mode 5 SOI = 20 BTDC
0
5
10
15
20
25
-10
0
10
20
30
40
50
60
70
-75 -60 -45 -30 -15 0 15 30 45 60 75
HR
R (J
/deg
)
Cyl
inde
r Pre
ssur
e (b
ar)
Crank Angle (deg)
100%DME20%NH3-80%DME40%NH3-60%DME
Mode 7 SOI = 15 BTDC
0
5
10
15
20
25
-10
0
10
20
30
40
50
60
70
-75 -60 -45 -30 -15 0 15 30 45 60 75
HR
R (J
/deg
)
Cyl
inde
r Pre
ssur
e (b
ar)
Crank Angle (deg)
100%DME20%NH3-80%DME40%NH3-60%DME
Mode 9 SOI = 25 BTDC
Sample Results (P & HRR)
Department of Mechanical Engineering, Iowa State University
• Observation on combustion • No significant deterioration of combustion • More ammonia longer ignition delays, more significant
premixed combustion
• Reporting emissions • Reported in BSEC [MJ/kWh] (instead of BSFC [g/kWh])
• Imply the fuel energy consumption rate, fuel economy • As reference: @ 3,250 rpm and 4.3kW running on diesel fuel
• BSEC is 13.656 MJ/kWh, corresponding to a BSFC of 304.8 g/kWh for the current engine.
Results
Department of Mechanical Engineering, Iowa State University
0
5
10
15
20
25
30
20 30 40 50 60 70 80
NO
x (g
/kW
h)
BSEC (MJ/kWh)
Single Injection, 100% DME Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
0
5
10
15
20
25
30
20 30 40 50 60 70 80
NO
x (g
/kW
h)
BSEC (MJ/kWh)
Single Injection, 20%NH3 - 80%DME Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
0
5
10
15
20
25
30
0 10 20 30 40 50 60 70 80
NO
x (g
/kW
h)
BSEC (MJ/kWh)
Single Injection, 40%NH3 - 60%DME Mode 3Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
NOx Emissions
Reference data using diesel fuel
Department of Mechanical Engineering, Iowa State University
0
5
10
15
20
25
30
20 30 40 50 60 70 80
NH
3 (g
/kW
h)
BSEC (MJ/kWh)
Single Injection, 20%NH3 - 80%DME Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
0
5
10
15
20
25
30
0 10 20 30 40 50 60 70 80
NH
3 (g
/kW
h)
BSEC (MJ/kWh)
Single Injection, 40%NH3 - 60%DME Mode 3Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
NH3 Emissions
Department of Mechanical Engineering, Iowa State University
NH3 Emissions
0
200
400
600
800
1000
1200
1400
1600
1800
20 30 40 50 60 70 80
NH
3 (p
pm)
BSEC (MJ/kWh)
20%NH3 - 80%DME Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
0
200
400
600
800
1000
1200
1400
1600
1800
0 10 20 30 40 50 60 70 80
NH
3 (p
pm)
BSEC (MJ/kWh)
40%NH3 - 60%DME Mode 3Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
Department of Mechanical Engineering, Iowa State University
0.000
0.025
0.050
0.075
0.100
20 30 40 50 60 70 80
Soot
(g/k
Wh)
BSEC (MJ/kWh)
Single Injection, 100% DME Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0 20 40 60 80
Soot
(g/k
Wh)
BSEC (MJ/kWh)
Single Injection, 20%NH3 - 80%DME Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
0.000
0.005
0.010
0.015
0.020
0.025
0.030
10 20 30 40 50 60 70 80
Soot
(g/k
Wh)
BSEC (MJ/kWh)
Single Injection, 40%NH3 - 60%DME Mode 3Mode 5Mode 7Mode 9Mode 11Mode 20Mode 21
Soot Emissions
• Extremely low soot emissions
• HC and CO levels comparable among different fuel mixtures
Department of Mechanical Engineering, Iowa State University
• Injection pressure – positive effects on combustion • To enable combustion of 60%NH3-40%DME
• P_inj=205 bar, SOI= 180 btdc, T_intake= 90 C • Achieved higher load and speed operation
60%NH3-40%DME
2500 rpm & 3.6 hp.
Department of Mechanical Engineering, Iowa State University
NOx and NH3 Emissions
0
5
10
15
20
25
30
35
40
45
50
80 100 120 140 160 180 200
NO
x [g
/kW
h]
Start of injection [oCA BTDC]
60%NH3 - 40%DME
60NH3_19_180_160NH3_19_180_260NH3_25_180_3
0
5
10
15
20
25
30
35
40
45
50
80 100 120 140 160 180 200N
H 3[g
/kW
h]
Start of injection [oCA BTDC]
60%NH3 - 40%DME
60NH3_19_180_1
60NH3_19_180_2
60NH3_25_180_3
Higher load benefits NH3 combustion; More stable operation; Flexibility in injection timing.
Department of Mechanical Engineering, Iowa State University
• Current test engine • Small size, high heat loss, operated at high speed, low injection
pressure • Application to larger diesel engine
• Operated at lower speed, high injection pressure • Exhaust after-treatment (SCR system without urea injection)
Perspectives
Diesel fuel 40%ammonia/60% diesel
40%ammonia/60% DME
Ammonia
BSEC (MJ/kWh) 10.3 10.3 10.3 10.3
LHV (MJ/kg) 42 32.6 24.5 18.6
Fuel rate (kg/kWh) 0.245 0.316 0.420 0.554
Fuel price ($/kg) $1.180 $0.950 $0.704 $0.605 Fuel energy cost ($/kWh)
$0.29 $0.30 $0.30 $0.34
Fuel cost based on $3.7/gal diesel, $550/ton ammonia, $700/ton DME
Department of Mechanical Engineering, Iowa State University
DISI NH3 Engine
• Direct injection of gaseous ammonia • Maximize volumetric efficiency, thus
maximizing air fuel charge • Prevent negative effects of high latent
heat of ammonia
• Solenoid driven pulse valve • Withstands corrosive effects of ammonia • Designed for gaseous applications • Cheap and readily accessible
Solenoid Valve
Pressure Transducer
Department of Mechanical Engineering, Iowa State University
Gaseous NH3 Injection
• Fuel pump and storage operate on liquid basis • Injection line pressure approx.
35 bar
• Injection line heated to achieve gaseous fuel • Temperature required 60°C • Heat provided by heat tape • Expansion chamber to
compensate for dramatic volumetric change upon vaporization
Pump
Ammonia Bottle
Pressurization Tank
Surge Tank
Pressure release Valve
Pressure Reducing Regulator
Fuel Scale
Department of Mechanical Engineering, Iowa State University
Progress Update
• Fuel storage, heating, injection systems completed. • Initial engine tests conducted
• Engine operates on gasoline • Engine torque increases when ammonia injection is activated
• Detailed measurements in progress
Department of Mechanical Engineering, Iowa State University 21
Summary • CI engines using ammonia
• Port induction of vapor ammonia + DI diesel fuel • DI ammonia/DME mixtures • Large engine will favor operation using ammonia • After-treatment using SCR for NOx and ammonia reduction
• DISI ammonia engine • Injection system implemented • Detailed measurements in progress