3rd International Conference LUBRICANTS RUSSIA - 2007 Diesel Particulate Filter Regeneration Strategy and its Influence on Engine Oil Characteristics Luca

3rd International 3rd International Conference LUBRICANTS Conference LUBRICANTS RUSSIA - 2007RUSSIA - 2007

Diesel Particulate Filter Regeneration Strategy and its Influence on Engine Oil CharacteristicsLuca Di Stefano

DIESEL PARTICULATE FILTER DIESEL PARTICULATE FILTER REGENERATION STRATEGY REGENERATION STRATEGY

AND ITS INFLUENCE ON AND ITS INFLUENCE ON ENGINE OIL ENGINE OIL

CHARACTERISTICSCHARACTERISTICS

Moscow – 28,29 november 2007

M. Fucale, A. PariM. Fucale, A. Pari

L. Di Stefano, A. Dotta, G. Natoli, G. Pometto, P. Salino L. Di Stefano, A. Dotta, G. Natoli, G. Pometto, P. Salino



Contents:

Scenario and objective of the activity

Testing activity

Results

Conclusions

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Emissions limits of D. I. Diesel Engines of passenger cars

0

0,02

0,04

0,06

0,08

0,1

0,12

0,14

0,16

0,18

0,2

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 1,1 1,2 1,3 1,4 1,5

HC+NOx [g/Km]

Part

icu

late

[g/K

m]

EURO 4EURO 3

EURO 2

EURO 1

To meet the stringent limit for the emission of particulate matter (PM)set by Euro 4 regulations, Diesel Particulate Filters (DPF) have beendeveloped for applications on Diesel Engines of Passenger Cars.

Moscow 2007



Diesel Particulate Filters must be periodically regenerated to remove the solid particulate matter accumulated with mileage.

Today the most widely adopted regeneration strategy is based on supplementary injections of fuel in order to reach the temperature needed to burn the particulate accumulated in the filter (approximately 600°C).

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REGENERATION STRATEGY

DPF

Pre Kat

Front Kat

Injector

Air inlet

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T/C

This quantity will burn inside the exhaust manifold



Several running parameters are recorded and processed by the Electronic Control Unit to determine the level of soot accumulation and activate regeneration whenever a pre-set value of soot is reached.

The rate of soot accumulation in the filter, and therefore the frequency of regeneration, is strictly dependent on driving conditions (urban, highway, combined).

To guarantee the protection of the whole system from failure, the temperature and the delta pressure between the filter ends are also constantly monitored. Moscow 2007



During the regeneration process, as a consequence of post injections, small fractions of fuel leak in the sump through cylinder liner, mixing with the oil.

The objective of the activity was to evaluate the impact of the resulting oil viscosity decrease on engine protection against wear, particularly of those mechanical couplings (shaft/bearings, cam/tappets) whose protection is highly dependent on oil film formation and stability.

To this purpose, different running conditions have been simulated in the lab, both on engine on test dynos and directly on a vehicle on the roller dyno. Results have been compared with data generated in a field test.

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The oil used in the tests is a SAE 5W40, ACEA B3/B4, synthetic formulation

Characteristic Method UnitTypical value

Kv 100°C ASTM D445 mm2/s 15.3

Kv 40°C ASTM D445 mm2/s 90.5

HTHS CEC L 36 A 97 mPa.s 3.7

Total Base Number

ASTM D2896 mgKOH/g 9.6

Sulphated Ash ASTM D874 % 1.1

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Experimental conditions:

Engine: 1.9 l, common rail, 8 valves, 85 kW,Euro 4 Total duration: 130 h Cycle:

Phase 1 - torque @ full/partial load Phase 2 - power @ full/partial loadrepeated alternatively

regeneration induced after each phase

No oil drain, no top up – samples were taken beforeand after each regeneration step

Test on dyno

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3%

15%

5%partial load

36%full load

5%partial load

36%full load

0

10

20

30

40

50

60

70

80

90

100

2,000 rpm 2,000 rpm 4,000 rpm 4,000 rpm Regeneration at 1,500 rpm

idle

Tes

t H

ours

Engine: 1,9 l Common Rail,8 valves, Euro 4DPF accelerated cycle - 195 h

Tests on dyno

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Experimental conditions:

Engine: 1.9 l, common rail, 8 valves, 85 kW,Euro 4 Total duration: 22,000 km Cycle: NEDC, repeated up to 22,000 km

engine stopped every 15 h, cooled down and started again

No oil drain, no top up – samples taken before and aftereach regenaration step for analysis

Test on roller dyno

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New European Driving Cycle (NEDC) ECE EUDC

195

1,180

Time (s)400

4.052 Km 6.955 Km

General dataLength:11.02 KmAverage speed: 33.6 Km/hTime: 20.3 min.

Test on roller dyno

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Field Test

A group of Fiat Stilo running with the SAE 5W40, ACEA B3/B4, synthetic oil used in the lab activity was monitored :

# 1 – 90,000 km in city driving conditions;# 2 – 99,000 km in combined driving conditions;# 3 – 60,000 km in combined driving conditions.# 4 – 180,000 km in highway driving conditions.

Oil drain interval: 30,000 km

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Engine 1.9 l Common Rail, 8 Valves, Euro 4

DPF Accelerated test on Dyno - Viscosity behaviour

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DPF Accelerated test on Dyno Bearing at the end of the test

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99,510

10,511

11,512

12,513

13,514

14,515

15,516

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 24000 26000 28000 30000

Test [Km]

Viscosity 100°C [mm2/s]

0

0,2

0,4

0,6

0,8

1

1,2

1,4

Soot [%]

11, 7

12, 07

11, 66

11, 91

11, 31

11, 62

11, 16

11, 45

10, 991 0,8

1 1

1 1 ,2

1 1 ,4

1 1 ,6

1 1 ,8

1 2

1 2 ,2


Roller Dyno test - Viscosity after regeneration

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Vehicle: Stilo 1.9 l Common Rail, 8 valves, Euro 4

Roller Dyno Test Bearing at the end of the test

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USED OIL ANALISYS (LAB AND FIELD) - VISCOSITY @ 100°CUSED OIL ANALISYS (LAB AND FIELD) - VISCOSITY @ 100°C

8,0

9,0

10,0

11,0

12,0

13,0

14,0

15,0

16,0

0 5000 10000 15000 20000 25000 30000

km

cSt

9,0 ROLLER DYNO FLEET CIT Y FLEET COMBINED FLEET HIGHWAY

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USED OIL ANALISYS (LAB AND FIELD) - SOOT %USED OIL ANALISYS (LAB AND FIELD) - SOOT %

0,0

1,0

2,0

3,0

0 5000 10000 15000 20000 25000 30000

km

%

ENGINE DYNO ROLLER DYNO FLEET CITY FLEET COMBINED FLEET HIGHWAY

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USED OIL ANALISYS (LAB AND FIELD)- TBN DEPLETIONUSED OIL ANALISYS (LAB AND FIELD)- TBN DEPLETION

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1,0

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3,0

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0 5000 10000 15000 20000 25000 30000

kM

mg

KO

H/g

ENGINE DYNO ROLLER DYNO FLEET CITY FLEET COMBINED FLEET HIGHWAY

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Conclusions – 1 Oil dilution and degradation

dilution due to regeneration and the resulting viscosity decrease are strictly dependent on driving cycle; city conditions are the most severe, not only because of more frequent regeneration steps, but also because of lower evaporation of light fraction of fuel compared to combined and highway conditions, where the oil reaches higher working temperatures;

as a consequence of fuel accumulation, other oil parameters are affected, such as the alkalinity reserve (T.B.N); higher dilution implies more rapid TBN depletion with running hours or kilometers;

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Conclusions – 2 Engine protection

under the tested conditions and with the tested oil no relevant wear phenomena occurred;

however engine inspection showed that failure of engine parts such as bearings might be an issue;

therefore, in view of further extended drain interval, oil life monitoring devices, which indicate when oil drain is necessary based on recording and processing engine running conditions, are highly advisable in conjunction with DPF to guarantee engine protection throughout its entire life.

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Thanks you Thanks you for your attention!for your attention!

Moscow 2007

M. Fucale, A. PariM. Fucale, A. Pari

L. Di Stefano, A. Dotta, G. Natoli, G. Pometto, P. Salino L. Di Stefano, A. Dotta, G. Natoli, G. Pometto, P. Salino

Documents

3rd International Conference LUBRICANTS RUSSIA - 2007 Diesel Particulate Filter Regeneration Strategy and its Influence on Engine Oil Characteristics Luca