INTERNAL DIESEL INJECTOR DEPOSITS

Transcription

1 INTERNAL DIESEL INJECTOR DEPOSITS

2 INTRODUCTION IDID What is it? DW10C CEC engine test development DW10C engine testing Innospec testing Vehicle Testing Conclusions

3 INTERNAL DIESEL INJECTOR DEPOSITS (IDID) Field issues reported where injector needles had stuck Problems associated with IDID include: Noise, especially when cold Cold start problems, or even failure to start Rough running and erratic idle Power loss and poor acceleration Possible bad actors Metal contaminants in fuel (Sodium, Zinc) Some additive components, e.g. Low Molecular weight PIBSI detergents

4 INTERNAL DIESEL INJECTOR DEPOSITS (IDID) Deposits can build-up higher up in the injector body The needle only has a couple of Microns clearance to the outer body Tiny amounts of deposits can cause the needle to stick in the body

5 TYPES OF DEPOSITS POSSIBLE SOURCES Fuel Water/Dirt Metallurgy && metal catalysts Bio-diesel blend storage sediment Injector & Filter deposition Pressure at injector in common rail engine Fuel thermal stress in common rail engine Temperature at injector in common rail engine Bio-contamination aerobic/non-aerobic Bio-diesel Additive/ reaction/degradation Additive Misuse Lube oil adulteration

6 TYPES OF DEPOSITS Numerous causes for fouling, but three basic types exist: Metal carboxylates white, soapy deposits, usually Na related Carbonaceous Black deposit typical of degraded fuel Amide-lacquering type reported to be linked to some detergents Injector deposits are mostly carbonaceous and caused by fuel oxidationdegradation (SAE papers, CRC panels, OEM discussions, etc.) Effect of temperature/pressure in newer HPCR injection systems increases the amount of deposits formed (all types)

7 TYPES OF DEPOSITS Amide Lacquer Metal Carboxylate Carbonaceous

8 INNOSPEC SAE PUBLICATIONS Paper SAE SAE SAE SAE SAE SAE SAE SAE SAE SAE SAE SAE Description Analysis of injectors and fuel filters by a range of analytical techniques Review of fuel stability literature and Industry Standard stability test data Use of a novel technique, hydropyrolysis, to analyse deposits Use of temperature programmed oxidation (TPO) to analyse diesel deposits Characterisation of fuel and injector deposits by various analytical techniques Historical review of deposit formation in diesel engines and development of test methods to assess fuels and additives & further hydropyrolysis analysis of filters and injectors Loss of HFRR performance with acidic lubricity improvers when fuel contacts caustic, no loss with ester additives Introduces the use of ToF-SIMS (Time of flight secondary ion mass spectrometry) to analyse deposits Sodium contamination of diesel fuel, its interaction with fuel additives and the resultant effects on filter plugging and injector fouling Understanding polyisobutylene succinimides and internal diesel injector deposits Internal injector deposits from sodium sources Information on the aromatic structure of internal diesel injector deposits from time of flight secondary ion mass spectrometry (ToF-SIMS)

9 INTERNAL DIESEL INJECTOR DEPOSITS CEC TEST DEVELOPMENT Test development complete using DW10C engine 1997cc 4 cylinders in line Common Rail 4 valves per cylinder 2000rpm Euro 5 compliant, Delphi injectors

10 DW10B DW10B VERSUS DW10C INJECTORS Made by Continental DW10C Euro 4 Euro 5 Prototype nozzle design, found to increase fouling effect Made by Delphi Standard Production injectors Piezo type operation Solenoid type operation 6 injection holes in nozzle 8 injection holes in nozzle 1600 Bar injection pressure 2000 Bar injection pressure

11 DW10C CEC IDID TEST DW10C is an official CEC test Coded CEC F Cost per test approximately EUR including reference fuel cost Test moved ahead with only Na + DDSA procedure Test reproducibility = 1 Merit Performance of ECOCLEAN technology is excellent

12 DW10C TEST CYCLE High speed/load test conditions 1 hour cycle repeated 6 times Followed by 4 hrs cold soak Above repeated 5 times Cold starts rated in between phases

13 DW10C DEMERIT SYSTEM Test has a complex rating system Based on Demerits Combination of 6 different parameters 2 parameters during cold starts 4 parameters during running phase (Operability) Creates numerous opportunities to lose merits Maximum of 75 merits available to lose Final result then divided by 7.5 (Don t ask!!)

14 0.5PPM NA + 10MG/KG DDSA BASE FUEL Engine ran for 18hrs, but would not re-start after soak period.

15 DW10C TESTING ECOCLEAN Exhaust Temps stayed the same from SOT to EOT Excellent IDID protection Final merit rating = 10

16 DW10C TESTING ECOCELAN Merit Rating = 10

17 DW10C ENGINE TESTING ECOCLEAN RATING Data below demonstrates excellent performance of ECOCLEAN technology DW10C test responds well to different additive levels In the absence of industry pass/fail criteria, good correlation of field and engine data provides us with confidence to suggest appropriate level of performance Candidate RF ppm Na + 10 mg/kg DDSA 4 RF ppm Na + 10 mg/kg DDSA + ECOCLEAN technology Merit 10

18 INJECTOR STICKING Vehicle Testing

19 VEHICLE TESTING INJECTOR STICKING Using EN590 fuel (B7) with no fuel adulteration, matched pair vehicle study performed One base fuel vehicle One additive vehicle ECOCLEAN After 15,000km, base vehicle would not start after reports of rough running Additised vehicle continued running normally for >15,000km

20 VEHICLE TESTING INJECTOR STICKING Nozzle stuck in needle Ball bearing in bucket Main shaft

21 VEHICLE TESTING INJECTOR STICKING Injectors sent to a specialist test facility for evaluation Additive injector Classed As good as new Base fuel injector observations Ball bearing stuck in bucket normally separated easily from injector Main shaft abnormal oily film on surface, fuel related Needle would not come free from nozzle. High pressure airline and ultrasonic bath could not separate components. Classed as failed components. Problem in exact position as proposed CEC test.

22 SUMMARY IDID performance is becoming a requirement for many fuel marketers in Europe Na/Acid contamination can still occur so consumers do need to be protected via suitable fuel additive use No official pass/fail criteria set by CEC but the following recommended Regular grades should achieve 8-9 merits Premium grades should achieve 9-10 merits The above targets consider 1 merit reproducibility of test