ANALYSIS & TESTING OF

FUEL OIL LUB OIL

INSULATING OIL &

HYDRAULIC FLUIDS

DIFFERENT TYPES OF OILS USED IN POWER PLANT

• FUEL OIL

• LUBRICATING OIL

• FIRE RESISTANT FLUID

• INSULATING OIL or TRANSFORMER OIL

FUEL OIL

• FUEL OILS BEING USED AT POWER STATIONS

- LDO

- HSD

- FO (FURNACE OIL)

- LSHS (LOW SULPHUR HEAVY STOCK)

LDO & HSD

• LOW VISCOSITY• LOW FLASH POINT• COSTLY• NO NEED OF HEATING• NO STEAM REQUIRED• CV ~10720 KCAL/KG• IDEAL FOR STARTING OF BOILER FROM

COLD

FURNACE OIL• MUCH HIGHER VISCOSITY THAN LDO OR HSD

• REQUIRES HEATING AT THE TIME OF UNLOADING & PUMPING

• PREHEATING UPTO 110 DEGC FOR USE

• BETTER ATOMISED WITH STEAM

• COMPARATIVELY CHEAPER THAN LDO & HSD

• CV ~ 10270 KCAL/KG

**LSHS- HIGHLY VISCOUS, CHEAPER THAN FO

Parameters Monitored of Fuel oil

• Standard: IS 1593/1971, Grades: LV-MV-HV

• API gravity: 12 sp. 0.986 at 15 degc

• Viscosity- 80-120-370 cst at 50 degc

• Flash point- 66 degC (min)

• Pour point

FO Monitoring…• GCV: 10270 kcal/kg

• Total Sulphur : 3.5-4.0-4.5% by weight

• Water Content

• Ash content • Sediments

FUNCTIONS OF FO

• Coal fired units contains oil burners having capacity of 15-20%

• Ignition energy to light off coal burners

• Stabilization of coal flame at low loads

• Safe and reliable heat input source during light up of boiler

PROPERTIES OF LUB OIL TO BE CHECKED

• KINEMATIC VISCOSITY: The Redwood viscometer determines the time usually expressed in sec required for a standard volume of oil to flow through a standard orifice at specified pr. & temp.

• Kinematic viscosity= const. x time

• Moisture content: By Crackle test or by Karl Fischer titration method

• Mechanical Impurities: A fixed volume of oil is dissolved in a solvent like Toluene or Pet. Ether and passed through pre weighed 45 micron filter paper.

MI is determined from difference in weight

• Foaming Characteristics• Copper strip corrosion• Emulsion Characteristics• Cloud and pour point• Acidity• Oxidation Characteristics • Flash point

PROPERTIES OF LUBRICATING OIL TO BE CHECKED

LIMIT OF DIFFERENT LUBE OIL

S.No Equipment Stage

Name of oil

Moisture (ppm)

MI(ppm)

Viscosity (cst)

1 MOT/BFP/ ID/FD

I SERVO PRIME-32

150 50 27.6-36.3

2 PA FAN I SP-68 150 50 60.8-79.2

3 CT FAN/ASPH

I SERVO SYSTEM-121

200 500 118-124

4 MILL GEAR HOUSING

I SERVO MESH SP-320

1000 0.1% 320-350

LIMIT OF DIFFERENT LUBE OIL

S.No

Equipment Stage

Name of oil

Moisture (ppm)

MI(ppm)

Viscosity (cst)

1 TURBINE II DAPHANE SUPER TURBINE-46

100 50 41.4-50.6

2 PA FAN/SAPH

II SERVO CYCLE-660

100 50 615-680

3 FD/ID II SERVO PM-68

100 50 64-72

4 TDBFP BRG & COUPLING

II SERVO PM-46 T

300 50 43-48

5

MDBFP II SERVO SYSTEM-HLP32

300 50 29-39

6 MAIN MILLLUBE UNIT

II SERVO SYSTEM-460

500 500 440-500

FIRE RESISTANT FLUID

FIRE RESISTANT FLUID

• FRF is known as phosphate ester hydraulic fluids.

• They are used in 500 MW turbine control system

• They are fire resistant, exhibit good resistance to oxidation hydrolysis, adequate air release and low foaming properties when compared to petroleum oil.

PARAMETERS OF FRF MONITORED

• Water Content-Potential for Hydrolysis• Fluid Cleanliness/ Particle Count• Total Acid No-Hydrolysis that has occurred• Mineral oil content• Air release• Viscosity• Resistivity

FRF POLISHING UNIT

• Mechanical filter and strainers removes mechanical impurities

• Fuller earth and activated alumina treatment to remove acidic ions. They acts as ion exchangers.

• Air drier or desiccant breather to remove moisture-moisture filter.

LIMIT OF DIFFERENT PARAMETERS

S.N Parameter Test Method Permissible Limit

1 Viscosity ASTM D-445 30-50 cst

2 Acid Number ASTM D-974 0.2 mg KOH/gm

3 Water Content ASTM D-1744 1500 ppm

4 Sediments AFNORE-48652 5 mg/100 ml

5 Particle Count ASTMF-662/322

Class 16/13

INSULATING OIL

USE OF INSULATING OIL

• Insulating oils are derived from mineral oil.

• Insulating oils are used in transformers, reactors switchgear and cables.

• It quenches arcs when switching.• Prevents glow discharge.• Act as a cooling agent.

AGEING OF OIL DURING OPERATION

• Increased temperature.• Absorption of gases mainly oxygen.• Absorption of water from atmosphere.• Ageing through contacts with metal

plates like copper and iron• High temperature decomposition.

• Dielectric breakdown test.

• Dielectric dissipation factor or tan-d.

• Specific resistances.

• Water content test.

• Acidity Test.

PARAMETERS OF INSULATING OIL MONITORED

RECONDITIONING OF INSULATING OIL

• Reconditioning of oil means removal of water and solid particles from oil.

• This is done by using several available type of filters, centrifuge and vacuum dehydrators.

• Filter removes mechanical impurities.• The centrifuge is used when there is large

amount of water or other contamination present.

• Vacuum dehydrator removes water and dissolved gases.

Condition Monitoring of HV Transformers and Reactors

by DGA technique

Degradation of insulating oil

• Electrical discharges or thermal stresses in the oil or solid insulator of an oil filled transformer produces gases.

• The most significant gases produced are hydrogen, methane, ethane, ethylene and actylene.

• The relative quantity of various gases depends on the energy available.

GASES GENERATED UNDER DIFFERENT CONDITION

S.N Phenomenon Gases Generated

1 Partial discharge H2 gas (mainly)

2 Little heating CH4,H2

3 Low temp. hotspot CH4

4 Moderately high temp hotspot

C2H4,C2H6

5 Very high temp hotspot C2H2 in significant amount.

Steps involved in D G Analysis• Sampling of oil - Stainless steel oil

sampling containers of capacity up to 1000 ml with needle valves and tube adaptors at both ends can be used for sampling.

• Gas Extraction from oil – Dissolved gases are extracted by degassing flask attached with a vacuum pump assembly. The extracted gas is then compressed to atmospheric pressure and volume of the gas is measured.

Steps involved in D G Analysis

• Analysis of gas extracted- The gas extracted can be analyzed by a Gas Chromatograph fitted with a thermal conductivity cell detector. The carrier gas is helium. The column used is poropak N and Molecular sieve 5A.The gases determined are Hydrogen, oxygen, nitrogen, methane, ethane, ethylene, acetylene, propane, propylene, CO, CO2 etc.

HYDRAULIC FLUIDS

MINERAL OIL HYD FLUIDS

• SOLUBLE IN WATER, FORMING EMULSIONS

• USED WHERE NOT MANY MOVING PARTS ARE INVOLVED

• CHEAP

• IF LEAK OCCURS, PRESENT A DEFINITE FIRE HAZARD AT ELEVATED TEMP

WATER/GLYCOL HYD FLUID

• BETTER OILLINESS THAN MINERAL OIL HF

• ARE REASONABLY FIRE RESISTANT

• FLUID BECOMES THICKER & STICKY AT HIGH TEMP

• WATER CAN BE ADDED TO RESTORE ITS ORIGINAL CONSISTENCY

• MORE EXPENSIVE THAN THE SOLUBLE MINERAL OIL HF

SYNTHETIC HYDRAULIC FLUID

• MAN-MADE PRODUCT

• CHEMICAL NAMES SUCH AS CHLORINATED HC & PHOSPHATE ESTERS

• HIGH RESISTANCE TO FIRE

• USED IN BOILER DAMPERS & OTHER SYSTEMS WHERE HIGH TEMP ARE ENCOUNTERED

• COSTS ABOUT 8 TIMES AS MUCH AS MOHF

THANK YOU