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ANALYSIS & TESTING
OF
FUEL OIL
LUB OILINSULATING OIL
&
HYDRAULIC FLUIDS
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ANALYSIS & TESTING OF OI LS
Different Types Of Oil Used In Power Plant
Fuel Oil
Lubricating Oil
Fire Resistant Fluid
Insulating Oil Or Transformer Oil
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FUNCTIONS OF FO
Coal fired units contains oil burners havingcapacity of 15-20%
Ignition energy to light off coal burners
Stabilization of coal flame at low loads
Safe and reliable heat input source during lightup of boiler
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1. FUEL OILS
LOW FLASH POINT FO LOW FLASH POINT FO
LDO & HSDFURNACE OIL
PROS CONSCONSPROS
Low viscosity
No need of heating
No steam required
Cv ~10720 kcal/kg
CostlyHIGHER VISCOSITY
Requires heating at the
time of unloading &
pumping preheating upto
110 degc for use
Better atomised with steam
Comparatively cheaper than
ldo & hsd
LSHS- HIGHLY VISCOUS, CHEAPER THAN FO
Cv ~10720 kcal/kg
IDEAL FOR STARTING OF
BOILER FROM COLD
COST EFFECTIVE
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Parameters Monitored of Fuel oil
Viscosity Index-- Rate of change of viscosity w.r.t temperature.=>Higher
the V.I better the oil will be and High V.I oil does not become thin with the
rise of temperature
LIMIT 80-120-370 cst at 50 0C.
Flash point-- Temperature at which an oil on heating under prescribedconditions gives off sufficient vapours to form mixture with the air, ignites
on the introduction of the test flame from std. apparatus. Indicates degree of
safety on storage,transpotation
LIMIT : 66 0C (min)
Pour point--It is lowest temp. which is multiple of 3C at which the oil
ceases to flow under prescribed conditions & is reported 3C higher than
it.Signifies the pump ability of the oil at low temp.
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GCV: 10270 kcal/kg
Total Sulphur : Sulphur causes wears in engine as result of its combustion by
products and hence is undesirable than the stipulated limits
LIMIT : 3.5-4.0-4.5% by weight
Water Content --Being good conductor of electricity and hence always better tokeep minimum possible ppm content.
Ash content-- Non combustible material remaining after a sample of the product
is completely burned. It could be dust , dirt or any other foreign matter
Oxidation stabilityIt is important to determine the life of the oil as oxidation
produces sludge ,acid and other deliterious products.
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A LUBRICANT CAN BE DEFINED AS A SUBSTANCE WHICH
IS ABLE TO REDUCE FRICTION, WEAR AND SURFACE
DAMAGE RESULTING UPON TWO SOLID SURFACES IN
RELATIVE MOTION
LUBE OIL OR LUBRICANT
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PROPPERTIES OF LUB OIL TO BE
CHECKED
KINEMATIC VISCOSITY: The Redwood viscometerdetermines the time usually expressed in sec required for astandard volume of oil to flow through a standard orifice atspecified pr. & temp.
Rate of change of viscosity w.r.t temperature.
Higher the V.I better the oil will be.
High V.I oil does not become thin with the rise oftemperature.
Kinematic viscosity= const. x time
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SENSORY TESTSAppearance-- It is the simplest test to check whether the oil is clear and bright not
hazy and cloudy. Hazy and cloudy appearance will indicate water
contamination. Check the suspended impureties, foaming etc.
Colour--This test is useful only with light coloured products. Darkeing in colourindicate either oxidation or contamination from external sources.
Odour--Used oils will normally have bad or oily odour, oxidized oils will have
burnt or pungent odour.
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Moisture content: By Crackle test or by CarlFischer titration method
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Mechanical Impurities:A fixed volume of oilis 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
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Foaming characteristics determination-- Foaming tendency of oil due to trapping ofair in it. Trapping air in the oil will result uneven spreading the oil film on themoving parts resulting to damage of the machinery
Copper strip corrosion-- covers the corrosiveness of the petroleum products tocopper
Emulsion characteristics--Ability of petroleum oil to separate from water subject towater contamination turbulence
Cloud and pour point
Acidity-- quantity of base expressed in mg. Of KOH required to neutralize all the
acidic constituents present in one gram of sample.Expressed in mg. KOH / gm. Ofthe sample
Oxidation characteristics
Flash point--
PROPERTIES OF LUBRICATING OIL TO
BE CHECKED
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LIMIT OF DIFFERENT LUBE OILS.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
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LIMIT OF DIFFERENT LUBE OIL
S.No Equipment Stage Name ofoil
Moisture(ppm)
MI(ppm)
Viscosity(cst)
1 TURBINE II DAPHANE
SUPER
TURBINE-46
100 50 41.4-50.6
2 PA FAN/SAPH II SERVOCYCLE-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 MILL
LUBE UNIT
II SERVO
SYSTEM-460
500 500 440-500
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HYDRAULIC OILS
Soluble in water, forming
emulsions
Used where not many
moving parts are involved
Cheap
If leak occurs, present a
definite fire hazard atelevated temp
MINERAL OILWATER/GLYCOL OIL
SYNTHETIC HYDRAULIC
FRF
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
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 Mineral oil
Hydraulic Fluid
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FIRE RESISTANT FLUID
FRF is known as phosphate ester hydraulic fluids.
They are used in 500 MW turbine control system
PROPERTIES:
They are fire resistant
exhibit good resistance to oxidation hydrolysis,
adequate air release and
low foaming properties.
These properties are when compared to petroleum oil
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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 Value-- Gives the measure of the ability of an oil to separate
entrained air. Trapped air tends to interfere with transmission of heat there byincreasing the operating temperature and also promoting the oxidation of oil.
Viscosity-
Electrical Properties-- Dielectric strength maximum voltage which oil canstand. Higher the value better the oil. Dielectric dissipation factor( bdv ) it isthe tangent of the angle delta by which the phase difference between theapplied voltage and resulting current deviate from tt/2 radian when dielectric ofthe capacitor consists of the insulating oil. Lower the tan delta better the oil.Specific resistance is the ratio of the dc potential gradient in volts percentimeter paralleling the current flow with in specimen to the current densityin amp. Per sq.Cm at a given instant time
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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.
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LIMIT OF DIFFERENT PARAMETERSS.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
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INSULATING OIL
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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.
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Dielectric breakdown test.
Dielectric dissipation factor or tan-d.
Specific resistances.
Water content test.
Acidity Test.
PARAMETERS OF INSULATING OIL
MONITORED
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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.
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RECONDITIONING OF INSULATING OIL
Reconditioning of oil means removal of water and solidparticles 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 orother contamination present.
Vacuum dehydrator removes water and dissolved gases.
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CONDITION MONITORING OF HVTRANSFORMERS AND REACTORS BY
DGA TECHNIQUE
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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 acetylene.The relative quantity of
various gases depends on the energy available.
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.
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STEPS INVOLVED IN D G ANALYSIS
Sampling of oil - stainless steel oil sampling containers ofcapacity 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. Theextracted gas is then compressed to atmospheric pressure andvolume of the gas is measured.
Analysis of gas extracted- The gas extracted can be analyzed
by a Gas Chromatograph fitted with a thermal conductivitycell detector. The carrier gas is helium. The column used isporopak N and Molecular sieve 5A.The gases determined areHydrogen, oxygen, nitrogen, methane, ethane, ethylene,acetylene, propane, propylene, CO, CO2 etc.
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CHEMISTRY QUESTIONS Q1. The analysis of transformer oil is carried out by
a. BGA b. CGA
c. TGA d. DGA
Q2. FRF oil is used in
a. governing system b. Combustion system c. Lubrication d none of these
Q3. Crackle test is used to test
a. MI of oil b. Moisture of oil
c. oil in water d. viscosity of oil
Q4. GCV of fuel oil is in the range
a. >10000kcal/kg b. between 3000 to 4000kcal/kg
c. between 4000 to0 10000kcal/kg d.
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THANK YOU