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OVERVIEW

Medium Speed Diesel Engine LubricationUsed Oil Analysis

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LUBRICATION OF MEDIUM SPEED DIESEL ENGINES

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LUBRICATION IN INTERNAL COMBUSTION ENGINES

Bearing Lubrication: Adequate Viscosity to form oil film

Piston Cooling: Oxidation Stability Cylinder Lubrication: Adequate

Detergency, Dispersancy, Alkalinity, Viscosity

Cam Shaft/Gear Lubrication: Adequate Anti-Wear & EP

Fuel/Lubricating Oil Compatibility

LUBE PROPERTIES REQUIRED

ENGINE DESIGN TRENDS

Longer Stroke, Stroke/Bore Ratios Higher Combustion Pressure Higher BMEP Higher Thermal Efficiency Fuel Oil Quality Anti Bore Polish Rings Miller timing EGR,SCR,etc Smaller Sumps

IMPACT OF HIGHER COMBUSTION PRESSURES

ON DEW POINT

EFFECT OF ABPR ON OIL CONSUMPTION & WEAR

The use of such a ring prevents the contact between the carbon deposits on the piston crown and the liner.

These deposits often cause liner polishing which results in gas blow-by, risk of scuffing and increase lube Oil consumption.

OTHER ENGINE DEVELOPMENTS

PRE-PROFILING & COATING

PLATEAU HONING

ANTI BORE-POLISHING RING

STRESSES ON TPEO

STRESS CAUSED BY CONSEQUENCESTHERMAL & OXIDATIVE STRESS

High Temperatures causing accelerated breakdown of lubricants

Deposits, Sludge, increased acid generation, corrosive wear of bearing materials, hot corrosion of piston crown, oil thickening, viscosity increase, shorter oil life

ACID STRESS Acids from combustion of S in fuels, Oxidation & Nitration products

Corrosive wear, deposits, loss of BN, shorter oil life

FUEL & ASPHALTENE STRESS

Changed nature of residual Fuels, Higher ingress of Asphaltenes (raw) from fuel pump leaks, & (burnt) from blow-past

Deposits, lacquers, hot corrosion, Oil thickening & shorter oil life

ENG COMPONENT STRESS - LO/ADDITIVE PROPERTY REQUIRED

CREATING & MAINTAINING AN OIL FILM

Viscosity is the a key propertySAE 30 & 40 are mainly used

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MAINTAIN CLEANLINESS OF

CRANKCASE,CYLINDER LINER & PISTON RING PACK

Detergents Dispersants are the key properties

Fuel Quality Deteriorating Fuel ingress Increasing pressuresCombustion conditions more severeBlowby of combustion gasesCentrifuge & FiterationLubricant Condition It is estimated that a 0.4mm thick

deposit layer in Piston Underside can cause a 100 C rise in Piston crown temperature

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NEUTRALIZE SULPHURIC ACID

Crudes contain Sulphur in varying quantities (0 – 4%)

Refinery processes tend to concentrate the Sulphur in the “bottom” residual products

Residual Fuels can contain up to 4.5% S

When residual fuels are burned, the S also combusts, combining with Oxygen from the air, forming acidic Sulphur Oxides

Alkalinity (BN) is the key propertySANJIV WAZIR 15

THE OIL IN USE

The engine hardly ever, apart from the first start up, enjoys unused, fresh oil

The engine requirements are met by a combination of oil performance reserve and the efficiency of the oil maintenance system

If the engine requirements are not met, undesirable consequences can occur, such as increased LO consumption, more frequent/unplanned oil changes, increase in fouling, wear & tear of components, more frequent maintenance, even engine damage & failure

OIL CIRCULATION & REPLENISHMENT SPEED CONDITION

LUBRICATING OIL SOURCES OF CONTAMINATION

MAINTAINING THE OIL CONDITION

Maintaining the oil within acceptable limits is a function of:1. Lube oil’s additive package reserve2. Degree of contamination from products of combustion & other

sources3. Excessive LO consumption due to leakage or poor engine

maintenance4. Degree of LO cleaning by filtration & separation (centrifuging)5. Frequency & amount of top-ups

Extended lubricating oil life or running hours can be obtained by optimising all these influences.

LUBRICATING OIL TREATMENT SYSTEM

………..TO SUMMARISE

Larger number of product types needed to suit the wide range of applications.

Matching the product to the application results in the lowest overall cost. Improved cleanliness is essential for modern engines operating on poor

quality residual fuel. OEMs now prefer Higher Viscosity products Higher BN products are becoming more common.

USED OILO ANALYSIS

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OWNER,EQUIPMENT &LO PARTICULARS

R.HRS OF EQPT & OIL, SAMPLING DATE

PHYSICAL & CHEMICAL PROPERTIES OF THE SAMPLE

SPECTROMETRY RESULTS

WEAR METALS

CONTAMINANTS

RATING OF CURRENT SAMPLE

ANALYSTS COMMENTS

SUGGESTED ACTIONS

RESULTS OF CURRENT SAMPLE

PAST SAMPLE RESULTS

TRENDING

HFO CONSTITUENTS

DP ENGINE #1

HFO CONSTITUENTS

RISING

DROPPING

DP PLANTDISCUSSION

Rise in KV and Drop in BN correlate well with the rise in Vanadium+ Nickel (and Na), hence ingress of Bunt/Unburnt Fuel components and Combustion by-products is likely to be the cause.

Soot/Insolubles levels are also up, supporting above hypothesis

Wear metal levels are satisfactory High KV could affect bearing cooling and result in temperature

rise Degradation of additives and ingress of combustion could

lead to increased air entrainment

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DP PLANTSUGGESTIONS

Source of ingress needs to be identified and rectified to minimise oil degradation.

Some likely source could be:Raw Fuel: Leakage from plunger/barrel, poor injector sprayCombustion By-products: Blow-past, Mixing of Combustion

gases in T/Charger Lubrication Maintain the OEM recommended SLOC by regular top-up and

sweetening (if required) Maintain operating parameters such as Oil, Water, Air,

Exhaust temperatures and pressures within specified limits

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