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
0.4
0.35
80
0.3
60
0.25
40
0.2
0.15
20
0.1
0
0.05
-20
0
0
5
10
15
20
IVC143 P
IVC143 HR
Value
1737
3.50 (30% Load)
55
143, 115, 100, 85
25
0.2 to 0.3
ULS 2007 Diesel
25
IVC85 P
IVC85 HR
-150
-120
-90
Intake Pressures (kPa) Tested
4mm Lift
1.5mm Lift
NAHRR
100°BTDC
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
0
1.00
-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
0.1
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
0.15
1
0.8
0.6
0.4
0.2
0
-160
NOx
130°BTDC
1.50
0.2
0.1
0.05
2.00
0.25
IVC (CA-ATDC)
115°BTDC
0.25
70
0
-60
0.25 IVC143
NOx (g/kW-hr)
IVC70 P
IVC70 HR
-10
2
1.8
1.6
1.4
1.2
PM (g/kW-hr)
-180
0.2
0
IVC115 P
IVC115 HR
100
*** Pressure and NAHRR curves shown are of 2007
ULS Diesel fuel; combustion of fuels were similar
Factor
Speed (rev/min)
Fuel Flow (kg/hr)
SOI (CA-BTDC)
IVC Timings (CA-BTDC)
EGR Rate %
Equivalence Ratio
Fuel Type
CA-ATDC
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
-5
-210
IVC Timing and Intake Pressure Sweeps
0.45
-10
-240
IVC143
120
-15
-270
128°
0.5
-20
-300
CA ATDC
140
-25
-330
3.50
Preliminary testing found increased valve
lift provided better combustion phasing
-20
CA-ATDC
4.00
NAHRR
Equivalence Ratio
-30
143°BTDC
4.50
100
Pressure (bar)
Value
1737
3.55 (30% Load)
4.47
0
55
0
IVC143
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)
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
20
1.00
0
-0.50
-360
Quiescent
60
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
7.00
2.50
2.44 liters
Valve Lift (mm)
Injector Type
8.50
4.00
PM (g/kW-hr)
Valve Train
(4 valve)
70°BTDC
10.00
80
NOx (g/kW-hr)
16.1 : 1
85°BTDC
130°BTDC
100
PM (g/kW-hr)
137.2 mm x 165.1 mm
100°BTDC
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