Transcript Slide 1

PCCI Investigation Using Variable Intake Valve
Closing in a Heavy Duty Diesel Engine
Ryan Nevin, Professor Rolf Reitz and Manuel Gonzalez
Funding Sponsors: Caterpillar and US Department Of Energy
Solenoid Driven IVA System
0.20
6
0.158mm
0.35
0.3
60
0.25
40
0.2
0.15
20
0.1
0
0.05
-20
0
0
5
10
15
20
Factor
Speed (rev/min)
Fuel Flow (kg/hr)
SOI (CA-BTDC)
IVC Timings (CA-BTDC)
EGR Rate %
Equivalence Ratio
Fuel Type
Value
1737
3.50 (30% Load)
55
143, 115, 100, 85
25
0.2 to 0.3
ULS 2007 Diesel
25
-180
4mm Lift
-150
-120
-90
IVC143 P
IVC115 P
IVC85 P
IVC70 P
IVC143 HR
IVC115 HR
IVC85 HR
IVC70 HR
0.25 IVC143
NAHRR
3.00
70°BTDC
85°BTDC
2.50
IVC143 IVC115 IVC100 IVC85 IVC85-CAM
193
207
207
236
207
207
221
221
248
221
221
235
234
262
241
--248
----259
0.2
0.15
85
Later IVC
70
0.1
0.05
85
115
143
130
115
0
0
0.5
1
1.5
2
2.5
3
3.5
NOx (g/kW-hr)
2007 ULS Fuel
Pre-2007 Fuel
IVC85 CAM
10
20
30
40
IVC130
IVC70
IVC115
IVC100
IVC85
IVC60
0.15
-30
0.50
-25
-20
-15
0.00
-10
-5
0
5
10
CA-ATDC
-0.50
-190
-175
-160
-145
-130
-115
-100
-85
4mm Lift
-70
1.5mm Lift
Boost
Increase
0.02
0.015
0.01
0.005
0
0.5
1
1.5
2
2.5
IVC143
IVC85
2010-NTE
IVC115
IVC85-CAM
IVC100
2007
• NOx decreases with IVC as
well as intake pressure increase
since intake air acts as a diluent
• PM decreases with IVC by
equivalence ratio increasing, and
the necessary temperatures for
oxidation are met
IVC143
IVC130
IVC70
IVC60
IVC115
3
0.15
1
0.8
0.6
0.4
0.2
0
-160
0.1
0.05
0
-145
-130
-115
-100
-85
-70
-55
IVC100
IVC85
PM
• NOx decreases with lower in-cylinder
temperatures, while PM increases due to
less available oxygen to oxidize soot
• Late IVC (i.e. 60°BTDC) is capable
of suppressing combustion
2010 Emissions Search
Factor
Speed (rev/min)
Fuel Flow (kg/hr)
EGR %
SOI (CA-BTDC)
IVC Timings (CABTDC)Temperature (K)
Intake
0.025
0.2
NOx
0
1.00
0.25
0.1
130°BTDC
1.50
2
1.8
1.6
1.4
1.2
IVC (CA-ATDC)
0.05
2.00
0.25
70
0
115°BTDC
NOx (g/kW-hr)
Intake Pressures (kPa) Tested
-10
-60
1.5mm Lift
100°BTDC
0
CA-ATDC
100
*** Pressure and NAHRR curves shown are of 2007
ULS Diesel fuel; combustion of fuels were similar
-210
IVC Timing and Intake Pressure Sweeps
80
PM (g/kW-hr)
• Average decrease of 50% in PM emissions
by using 2007 ULSD over pre-2007 #2 diesel
fuel
• Although enough oxygen is being entrained
into the cylinder, the soot increases after a
certain IVC timing since the combustion
temperatures drop below necessary oxidizing
temperatures
-240
IVC143
0.4
-5
-270
0.2
128°
0.45
-10
-300
CA ATDC
120
-15
-330
3.50
Preliminary testing found increased valve
lift provided better combustion phasing
-20
CA-ATDC
4.00
0.5
-20
-30
143°BTDC
4.50
140
-25
0
IVC143
NAHRR
Equivalence Ratio
5.50
CA ATDC
EVC = -355 deg ATDC
IVC = -143 deg ATDC
EVO = 130 deg ATDC
IVO = 335 deg ATDC
Hydraulically Driven
Electronically Controlled
Unit Injector (HEUI 300B)
Up to 150MPa
40
PM (g/kW-hr)
Quiescent
60
20
1.00
0
-0.50
-360
100
Pressure (bar)
Value
1737
3.55 (30% Load)
4.47
0
55
7.00
2.50
2.44 liters
Constant A/F Ratio IVC Sweep
with Different Diesel Fuels
Factor
Speed (rev/min)
Fuel Flow (kg/hr)
Air Flow (kg/min)
EGR Rate %
SOI (CA-BTDC)
8.50
80
Value
1737
3.25 (25% Load)
184
55
0
Value
1737
3.0 (25% Load)
40
55
143, 85 (Solenoid)
305
• NOx decreased by factor of 2.5
solely through late IVC
• 2010 NTE NOx and PM levels
met through lowering temperature
and increasing equivalence ratio
through use of late IVC timing
Run
Intake Pressure (kPa)
Intake Flowrate (kg/min)
IVC (CA-ATDC)
NOx (g/kW-hr)
HC (g/kW-hr)
PM (g/kW-hr)
Equivalence Ratio Φ
3
6
9
184
184
172
2.52
2.03
1.86
-143
-85
-85
0.832
0.339
0.239
0.932 1.4232 1.6085
0.0103 0.0206
0.018
0.265 0.2886 0.3391
University of Wisconsin Engine Research Center
0.025
6
8
0.02
9
0.015
0.01
3
0.005
0
0
0.2
0.4
0.6
0.8
1
NOx (g/kW-hr)
Case 3 (IVC143)
Case 6 (IVC85)
Case 9 (IVC85)
2010-NTE
Case 8 (IVC85)
140
0.4
120
0.35
0.3
100
0.25
80
0.2
60
0.15
40
0.1
20
0.05
0
0
-30
-20
-10
0
10
20
30
CA ATDC
IVC143 (Case 3) P
IVC85 (Case 6) P
IVC85 (Case 9) P
IVC143 (Case 3) HR
IVC85 (Case 6) HR
IVC85 (Case 9) HR
40
NAHRR
Injection
Pressure
Nozzle Holes
Nozzle Hole
Diameter
Spray Angle
70°BTDC
10.00
4.00
Valve Lift (mm)
Injector Type
85°BTDC
130°BTDC
100
NOx (g/kW-hr)
16.1 : 1
100°BTDC
PM (g/kW-hr)
137.2 mm x 165.1 mm
PM (g/kW-hr)
Valve Train
(4 valve)
115°BTDC
11.50
Mexican Hat with Sharp
Edge Crater
Piston
Pressure (bar)
14.50
13.00
Factor
Speed (rev/min)
Fuel Flow (kg/hr)
Intake Pressure (kPa)
SOI (CA-BTDC)
EGR Rate %
120
16.00
Valve Lift (mm)
Bore x
Stroke
Compression
Ratio
Displacement
Combustion
Chamber
140
Valve Lift Curves
Caterpillar 3401 SCOTE
(Single Cylinder Oil Test
Engine)
- single cylinder
- direct injection
- 4 valve
Engine
Baseline IVC Sweep
Pressure (Bar)
Experimental Setup