february 28, 2006 ® southwest research institute ® engine lubricants research department overview...
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February 28, 2006 ® Engine Selection Current MY 4-cyl engine desired for current applicability and lower test cost Hardware solicited from Detroit Big 3 – no commitments SwRI forced to use engine ‘on-hand’ in interest of time 2002 Chevrolet Malibu 3.1L V-6TRANSCRIPT
February 28, 2006 ®
Southwest Research Institute ®
Engine Lubricants Research Department
Overview of SwRI IR&D Program To Study Engine Oil Formulation Effects on Catalyst Poisoning in an Engine Dynamometer Test
Presented to the GF-5 Emissions System Compatibility Improvement Team
byScott Ellis
February 28, 2006 ®
Introduction
• IR&D Program: Development of an Engine Dynamometer Test to Evaluate Crankcase Phosphorus Formulation Effects on Catalytic Converters
• Program Duration: July 2005 through June 2006
• Objective: Investigate feasibility of using an engine dynamometer test stand as evaluation platform for engine oil propensity to poison catalytic converters
• Emphasis: Utilize knowledge gained during and since OPEST and OPEST II with special focus on phosphorus volatility
• Approach: Run 4 tests using Afton 2002 Taxi Fleet oils 33 and 35 to demonstrate PCV-borne phosphorus effects, repeatability, and discrimination
February 28, 2006 ®
Engine Selection
• Current MY 4-cyl engine desired for current applicability and lower test cost
• Hardware solicited from Detroit Big 3 – no commitments
• SwRI forced to use engine ‘on-hand’ in interest of time
• 2002 Chevrolet Malibu 3.1L V-6
February 28, 2006 ®
Desired Test Cycle Features
• 150 °C oil temperature to maximize P-volatility in crankcase and ring-belt area
• Maximize blowby flow to transport ring-belt phosphorus into crankcase
• Maximize PCV flow to transport crankcase phosphorus into engine intake
• Catalyst inlet temperatures representative of field poisoning scenarios
February 28, 2006 ®
Initially Proposed Test Cycle
Parameter Stage 1 Stage 2 Stage 3 Stage 4 UnitsEngine Speed 4,500 4,500 4,500 4,500 rpmEngine Torque 50% of rated Full Full 50% of rated N*mCatalyst Inlet Temperature ~700 ~750 820 max ~700 o CCoolant Outlet Temperature 95 95 95 95 o COil Sump Temperature 150 150 150 150 o CDuration 60 60 10 50 secondsEngine Fueling Stoichiometric Over-fueling Over-fueling StoichiometricAir Injection Off Off On On
February 28, 2006 ®
Oil Temperature Control
• 150 °C can be maintained with GM 3.1L at 3500 rpm
• Potential phosphorus pathways
February 28, 2006 ®
PCV Flow Rate Studies
• PCV/blowby both maximum at 3500 rpm, 45 % throttle anglePCV Rate
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
19.40 25.49 31.28 36.93 42.30 47.50 52.63 57.63 62.61 67.30 71.87 76.46 80.89 84.94 89.11 93.12 96.91
% Throttle Pos. (calc.)
lpm
Average of BLOWBY Average of PCV_FLOW Average of FRSHFLOW
Note: All flows corrected to 20 °C and 1 atm
February 28, 2006 ®
PCV Flow Rate Studies
• Exhaust temperature maximum at 3500 rpm, 58 % throttle angleExhaust Temps
650.00
670.00
690.00
710.00
730.00
750.00
770.00
790.00
810.00
830.00
19.40 25.49 31.28 36.93 42.30 47.50 52.63 57.63 62.61 67.30 71.87 76.46 80.89 84.94 89.11 93.12 96.91
% Throttle Pos. (calc.)
deg.
C
Average of TEXHAUST Average of TEXHBC
February 28, 2006 ®
PCV Flow Rate Studies
• O2S voltage indicates fueling not stoichiometric at 3500 rpmO2 Sensor Voltage
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
19.40 25.49 31.28 36.93 42.30 47.50 52.63 57.63 62.61 67.30 71.87 76.46 80.89 84.94 89.11 93.12 96.91
% Throttle Pos. (calc.)
Volts
Note: plotted are 5 min. average of 10 sec. data
February 28, 2006 ®
Desired Revisions to Test Cycle
• Utilize max. PCV condition (3500 rpm, 45 % throttle) for approx. 2/3 of test cycle
• Use full-rich condition for approx. 1/6 of test cycle
• Use stoichiometric condition for approx. 1/6 of test cycle
• Need to check for soot accumulation on catalyst face
• May need air injection at stoichiometric condition to oxidize soot
February 28, 2006 ®
Revised Test Cycle
* May need air injection if soot accumulation is evident
Parameter Stage 1 Stage 2 Stage 3 Stage 4 UnitsEngine Speed 2,500 3,500 3,500 3,500 rpmThrottle Position 25 45 Full 45 %Catalyst Inlet Temperature ~700 ~800 ~750 ~800 o CCoolant Outlet Temperature 120 120 120 120 o COil Sump Temperature 150 150 150 150 o CDuration 60 120 60 120 secondsEngine Fueling Stoichiometric Slightly Rich Full Rich Slightly RichAir Injection Off* Off Off Off
February 28, 2006 ®
Phosphorus Retention Study
• Use same methodology as SAE paper 2003-01-1988
100 P P
Ca Ca Retention Phosphorus %
new
drain
drain
new
February 28, 2006 ®
Phosphorus Retention Study
• Performed 24-hr repeat runs on revised test cycle with 10 ml oil samples every 2 hours
% Phosphorus Retention
50.00
55.00
60.00
65.00
70.00
75.00
80.00
85.00
90.00
95.00
100.00
0 2 4 6 8 10 12 14 16 18 20 22 24
Hours
% P
Ret
entio
n
Phosphorus (Run 1) Phosphorus (Run 2)
February 28, 2006 ®
Research Catalysts
• Six units obtained, one baseline, four tests, one spare
• Approximately 1 liter volume
• Pd-only wash coating
• 900 c.p.i.
• Sliced 1” segment from face for core samples
• Reassembled in can with Interam packing
• Thermocouples installed approximately ¾” from face
February 28, 2006 ®
Next Steps
• Run 10-hour degreen segment on baseline catalyst– Measure conversion efficiency in SGR (1” core sample from catalyst face)– Look for evidence of soot deposition on catalyst face
• Run 300-hr test on Oil 33– Measure conversion efficiency on 1” core sample @ 150, 200, 250 and 300 hours– Determine test length required for significant degradation
• Run X-hour test on Oil 33 with PCV de-coupled
• Run X-hour test on Oil 33 for repeatability
• Run X-hour test on Oil 35 for discrimination