4-gas compressors.pptx

Copyright of INSERT COMPANY NAME HERE 121/04/2023

RECIPROCATING COMPRESSORS

Peru Talara

November, 2012

204/21/2023

SECTION OBJECTIVES

Overview of various compressor types

Picture or diagram of a reciprocating compressor, identify the location and function of each part

Lubricated parts and Recommended Lubricants


GAS ENGINE + RECIPROCATING COMPRESSOR

Reciprocating Compressor

Gas Engine

The combination of gas engine and reciprocating compressor is the most prevalent configuration in the gas industry.

• In most situations, a reciprocating compressor driven by a gas engine is the most economical means to perform the required compression.

• Of course, a gas engine makes perfect sense as a prime mover because it is fueled by natural gas – a fuel that does not have to be transported to the site because it is already there!

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Compressor Types

Operation and Components

Lubrication

Reciprocating Compressors


COMPRESSORS

POSITIVE DISPLACEMENT

Direct Increase in pressure by reducing the volume of the chamber in which a gas is confined

DYNAMIC

Increases gas pressure by increasing the gas's velocity

COMPRESSOR TYPES

ROTARY

AXIAL FLOW

CENTRIFUGAL

RECIPROCATING

ROTARY SCREW

ROTARY VANE

STRAIGHT LOBECompressors are divided into two major types, positive displacement and dynamic.


COMPRESSORS


DYNAMIC


ROTARY

AXIAL FLOW

CENTRIFUGAL

RECIPROCATING

ROTARY SCREW

ROTARY VANE

STRAIGHT LOBE

Positive displacement compressors move a fixed volume of gas. For example, a piston displaces a set volume on each stroke. As a rotary screw turns, it moves a set volume of gas.


COMPRESSORS


DYNAMIC

DYNAMIC COMPRESSORS

ROTARY

AXIAL FLOW

CENTRIFUGAL

RECIPROCATING

ROTARY SCREW

ROTARY VANE

STRAIGHT LOBE

Dynamic compressors use velocity to move gas, much as a fan blows air. The different types require different lubrication.


COMPRESSORS


DYNAMIC

POSITIVE DISPLACEMENT ADVANTAGES

ROTARY

AXIAL FLOW

CENTRIFUGAL

RECIPROCATING

ROTARY SCREW

ROTARY VANE

STRAIGHT LOBE

Reciprocating • High pressure / Multi-Stage /

Portable

Straight Lobe & Helical Lobe • Portable / Easy to Lubricate

Sliding Vane • Efficient / Small

Liquid Piston • High Volume / Easy to Lubricate


COMPRESSORS


DYNAMIC

DYNAMIC ADVANTAGES

ROTARY

AXIAL FLOW

CENTRIFUGAL

RECIPROCATING

ROTARY SCREW

ROTARY VANE

STRAIGHT LOBE

Centrifugal • Large volumes at low pressures at

high speeds.

Axial Flow • Direct connected to turbines and

rotors with high volumes.


Separable

Integral


1104/21/2023


Compressor Types

Operation and Components

Lubrication


RECIPROCATING COMPRESSORS

The motion of the pistons reduces the volume of the gas and therefore increases its pressure.

In contrast, a gas engine uses reciprocating motion to make rotary motion.

Since both the gas engine and reciprocating compressor convert between reciprocating and rotary motion, they each use many similar components, including pistons, cylinders, valves, crankshaft, crankcase, and connecting rods.

Reciprocating compressors take rotary motion from the driver and convert it into reciprocating motion in the form of the motion of the compressor's pistons.


RECIPROCATING COMPRESSOR

Take a look, one by one, at the major components of a reciprocating compressor.



Connecting Rod

The connecting rod transmits power from the crankshaft (input shaft) to the crosshead.

The connecting rod transmits power from the crankshaft (input shaft) to the crosshead.



Suction Line

Crosshead & Crosshead

Guides

The crosshead transmits power from the connecting rod to the compressor rod. Transfers rotating motion to linear motion.

The crosshead is supported by the crosshead guide.

The crosshead transmits power from the connecting rod to the compressor rod. Transfers rotating motion to linear motion.

The crosshead is supported by the crosshead guide.

Connecting Rod




Guides

Connecting

Rod

Compressor Rod

The compressor rod gives power to the piston.

The compressor rod gives power to the piston.




Guides

Compressor Piston & Rings

Connecting

Rod

Compressor Rod

The pistons take power from the compressor rod and move in the cylinder to reduce the gas volume, which compresses the gas.

The rings wrap around the piston and are what actually contact the cylinder.

The pistons take power from the compressor rod and move in the cylinder to reduce the gas volume, which compresses the gas.

The rings wrap around the piston and are what actually contact the cylinder.




Guides


Suction Valves

Gas to be compressed (the suction gas) enters the cylinder through the suction valves when they open. The valves open when the suction line pressure becomes greater than the cylinder pressure.

Gas to be compressed (the suction gas) enters the cylinder through the suction valves when they open. The valves open when the suction line pressure becomes greater than the cylinder pressure.

Suction Line

Connecting Rod

Compressor Rod




Guides


Discharge Valves

Suction Line

Connecting Rod

The compressed gas (discharge gas) leaves the cylinder through the discharge valves when they open. The valves open when the cylinder pressure becomes greater than the discharge line pressure.

The compressed gas (discharge gas) leaves the cylinder through the discharge valves when they open. The valves open when the cylinder pressure becomes greater than the discharge line pressure.




Guides

Pressure Packing Suction Line

“Pressure packing" is sometimes called "rod packing" and "oil wiper packing" is sometimes just called "wiper packing".

The combination of the "pressure packing" and the "wiper packing" is called the "compressor packing" or just the "packing."

Suction Valves


Compressor Rod

The pressure packing is a seal that prevents the gas in the cylinder from entering the crankcase through the compressor rod opening.

The pressure packing is a seal that prevents the gas in the cylinder from entering the crankcase through the compressor rod opening.




Guides

Oil Wiper

Packing

Is an oil seal that keeps crankcase lubricant from getting into the pressure packing.

It gets its name because it wipes excess oil off of the compressor rod.

Is an oil seal that keeps crankcase lubricant from getting into the pressure packing.

It gets its name because it wipes excess oil off of the compressor rod.

Suction LinePressure Packing


Suction Valves




Guides


Cylinder

Coolant Area

Suction LineOil

Wiper Packing

Pressure Packing

Suction Valves Connecting

Rod

Compressor Rod

Can you find the coolant area under the compressor cylinder?

Can you find the coolant area under the compressor cylinder?


RECIPROCATING COMPRESSOR 8


Guides


Cylinder

Coolant Area

Suction Valves Compressor

Frame Footings or

Anchor

Suction LineOil

Wiper Packing

Pressure Packing

Connecting Rod

Compressor Rod

If not torqued correctly, misalignment can result.

If not torqued correctly, misalignment can result.




Guides


Cylinder

Coolant Area

Suction Valves Compressor

Frame Footings or Anchor

Connecting Rod

Compressor Rod

Suction LineOil

Wiper Packing

Pressure Packing

CrankcaseBreather

The crankcase breather allows excess air in the crankcase to escape and avoid crankcase pressure build-up that would otherwise rupture seals.

The crankcase breather allows excess air in the crankcase to escape and avoid crankcase pressure build-up that would otherwise rupture seals.

ANIMATION OF RECIPROCATING COMPRESSOR

Horizontally opposed compressor


COMPRESSOR WITH INTERCOOLER

This is a two-stage compressor with intercooler.

Reciprocating compressors can have different shapes, but the components are the same as in the previous slides.


COMPRESSOR WITH INTERCOOLER

An intercooler is necessary for good efficiency because gas temperature increases when it is compressed. The hotter the gas is, the more work it takes to compress it.

The Intercooler cools the gas between stages of compression so it will take less work in the next compression stage.


STAGES & PISTON DIAMETERS

What is a 2-stage, 3-stage, or 4-stage compressor?

A 2-stage compressor raises the pressure of the gas twice (in 2 stages), while a 3-stage compressor raises the pressure of the gas 3 times (in 3 stages), and so on.

In a 2-stage compressor, for instance, the gas will be compressed in the 1st stage from one pressure to another pressure, cooled in the intercooler and then compressed in the 2nd stage to a higher pressure. Multiple stages are used to compress gas to higher pressures.

A compressor's number of stages can be determined by noting the number of different piston diameters it has. If the compressor uses pistons with three different piston diameters then it's a 3-stage compressor. (Note: The number of pistons a compressor has is not indicative of whether a compressor is multi-stage.)


CAN YOU FIND THESE?

Suction ValvesCrosshead & Crosshead

GuidesConnecting Rod

Piston & RingsCompressor PackingCompressor Rod

Can you find these?


LUBRICATION AREAS

Reciprocating compressors have three distinct areas for lubrication:• Crankcase (bearings, bushings, timing gears, crosshead

guides, etc.)

• Packing (oil wiper packing and pressure packing)

• Cylinders (cylinder walls, piston rings, and valves)Although most compressors use the same oil to lubricate all three (usually a gas engine oil), some applications require that a different lubricant be used to lubricate the packing and cylinders.

Many hydrocarbon compressors are moving toward “dry” or non-lubricated packing. Cylinders are sometimes lubricated by the material being compressed.


CIRCULATION LUBRICATION

The first system is an oil circulation system that lubricates the crankcase area. The oil circulation system uses an oil pump to circulate oil from the pool of lubricant that fills the compressor crankcase to the various lubricated components in the crankcase (main bearings, rod bearings, crosshead guides, etc.).

The 3 areas that need lubrication (crankcase, packing & cylinders) are lubricated by two separate systems.


FORCE FEED LUBRICATION

The second system is a force feed lubrication system that lubricates the packing and cylinders (the other two areas) via tubing. The force feed lubrication rate can be adjusted by the operator to deliver more or less oil to the packing and cylinders.

Force Feed

Lubricator


LUBRICATION

For the majority of compressors driven by gas engines, the oil used in both the compressor crankcase (oil circulation system) and in the force feed lubrication system (for the cylinders & packing) will be the same as the oil used in the gas engine.

Of course, since integral compressors share their crankcase with the engine, engine oil must be used in the circulation system as there is no separate compressor crankcase.

If a separable compressor is turned by a gas engine, the compressor crankcase will almost always use the same gas engine oil the engine uses. However, if turned by an electric motor or another driver, the compressor crankcase may be filled with a circulating oil like? Mineral, PAO, PAG, compounded.

Reciprocating compressor crankcases typically use an SAE 30 (ISO VG 100) or an SAE 40 (ISO VG 150-220).

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GAS ENGINE OILS

Gas engine oils are formulated for the engine rather than the compressor.

The engine's operating conditions dictate the type of gas engine oil recommended.

• Once the engine oil recommendation has been made, the compressor's operating conditions are analyzed to determine whether the engine oil can also be used to lubricate the compressor.

• In the majority of cases, the same gas engine oil used to lubricate the engine can also lubricate the reciprocating compressor.

• Gas Engine Oil is NOT THE PRIMARY lubricant OEM Recommendation!


LUBRICATION

The force feed lubrication system (for packing and cylinders) will usually use the same oil as the compressor crankcase (usually gas engine oil, but sometimes circulating oil).

The exception to this is when the gas will be compressed above 1,000 psig (pounds per square inch gauge) in pressure or when the gas is not pipeline quality natural gas. In these cases, the TA and OEM recommendation should be consulted to provide the proper product recommendation*.

Lubricant selection is gas quality and discharge pressure dependent


ALL LOSS SYSTEM

The force feed lubrication system to the packing and cylinders is an “all loss” system. This means that all oil supplied to the packing and cylinders mixes with the gas and leaves with the discharge gas into the pipeline.

Shell Technical Advisors can do compressor cylinder feed rate studies (*) to: a) Reduce oil usageb) Improve valve lifec) Reduce problems down stream of the compressor due to excessive oil feed to cylinders.

Improper feed rates can cause numerous problems, including:

• Valve sticking (too much feed)• Valve wear (not enough feed)• High oil consumption (too much)• Problems downstream – even flash fires

ARIEL CIGARETTE PAPER TEST METHOD

Checking cylinders for the proper lubrication rates, the cigarette paper test method can provide a practical indication.

Remove a head end suction valve and position piston at inner center, for the cylinder to be checked. Use two layers of regular unwaxed commercial cigarette paper, together. Wipe the cylinder bore at top with both papers using light pressure in circumferential motion through about 20°. The papernext to the bore should be stained (wetted with oil), but the second paper should not be soaked through. Repeat the test at both sides of the bore at about 90° from the top, using two new clean papers for each side. When the paper next to the bore is not stained through, it may be an indication of under lubrication. When both papers are stained through, it may be an indication of over lubrication.

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LUBRICANT GUIDANCEAriel Reciprocating Compressors

Gas Stream

90% Market Share 10% Market Share

Cylinder Discharge Pressure

<1000 PSIG<(70 bar-g)

1000 to 2000PSIG

(70 to 140 bar-g)

2000 to 3500PSIG

(140 to 240 bar-g)

3500 to 5000PSIG

(240 to 345 bar-g)

>5000 PSIG>(345 bar-g)

Pipeline Qualitynatural Gas

Including CNG(Dry)

ISO 150(R&O, Syn)

Morlina S2 B 150Morlina S4 B 100 (PAO)

ISO 150-220(R&O, Syn)

Morlina S2 B 150-220Morlina S4 B 100-150

(PAO)

ISO 220(Compounded, Syn)

Gas Compressor Oil S3 PSN 220

Morlina S4 B 150 (PAO)

ISO 320-460(Compounded, PAG)

Omala S1 W 460Omala S4 WE 150 (PAG)

ISO 460-680(Compounded, PAG)Omala S1 W 460-680

Omala S4 WE 150 (PAG)

Natural Gas(Water Saturated

and/or HeavyhydrocarbonsMethane<90%Propane>8%

SG>0.7)

ISO 150-220(R&O, Syn)


(PAO)

ISO 220-320(Compounded, PAG)


ISO 460-680(Compounded, Syn)

Omala S1 W 460-680Morlina S4 B 220-320

(PAO)

ISO 680(Compounded, PAG)




Gas Compressor Oil S4 PN 220 (PAG)


and Carbon Dioxide

>2% to 10%)

ISO 150-220(R&O, Syn)


(PAO)



Morlina S4 B 100-150 (PAO)









and Carbon Dioxide>10%)

ISO 150-220(R&O, Syn)


(PAO)











Consult your Shell LTA for actual product recommendation

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LUBRICANT GUIDANCEAriel Reciprocating Compressors

Gas Stream

90% Market Share 10% Market Share

Cylinder Discharge Pressure

<1000 PSIG<(70 bar-g)

1000 to 2000PSIG

(70 to 140 bar-g)

2000 to 3500PSIG

(140 to 240 bar-g)

3500 to 5000PSIG

(240 to 345 bar-g)

>5000 PSIG>(345 bar-g)


and H2S>2% to 30%)










Omala S1 W 460Omala S4 WE 150 (PAG)Morlina S4 B 150 (PAO)


Omala S1 W 460-680Morlina S4 B 220-320 (PAO)

Omala S4 WE 220 (PAG)Gas Compressor Oil S4 PN

220 (PAG)


and H2S>30%)










Omala S1 W 460Omala S4 WE 150 (PAG)Morlina S4 B 150 (PAO)



Omala S4 WE 220 (PAG)Gas Compressor Oil S4 PN

220 (PAG)

Air or gas mixtures with >4% oxygen

ISO 100(Diester or Polyol ester)

Corena S4 P 100





Nitrogen(Bone Dry - Contact Ariel)

ISO 150(R&O, Syn)


ISO 150-220(R&O, Syn)

Morlina S2 B 150-220Morlina S4 B 100 (PAO)

ISO 220(R&O, Syn)


ISO 320(R&O, Syn)





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COMPARING VISCOMETRICS @ 300ºF

Shell product Base Fluid Ariel Type ISO cSt @ 40C cSt @ 100C VI cSt @ 149 C (300F)40C VG Class @ 300F

(undiluted)

Corena S4 P 100 Diester Diester 100 100 10.2 78 3.8 <150

Corena S2 P 150 Mineral Compressor 150 155 12.1 52 4.1 <150

Morlina S4 B 100 PAO Syn 100 100 12.8 130 5.0 150

Morlina S2 B 150 Mineral R&O 150 150 15 95 5.4 150

Gas Compressor Oil S3 PSN 220 Syn Blend R&O 220 211 17.9 92 6.0 220

Morlina S2 B 220 Mineral R&O 220 220 18.3 92 6.1 220




Omala S4 WE 150 PAG PAG 150 136 22.5 188 9.2 460


Omala S1 W 460 Mineral Compounded 460 460 31.2 98 9.4 460

Omala S1 W 680 Mineral Compounded 680 680 35.2 83 9.8 680


Omala S4 WE 220 PAG PAG 220 222 34.4 203 13.5 1000

Gas Compressor Oil S4 PN 220 PAG PAG 220 198 34.8 223 14.3 1500


Gas Compressor Oil S4 PV 220 PAG PAG 220 190 36 200 15.2 1500

Omala S4 WE 320 PAG PAG 320 321 52.7 230 20.6 2200

Omala S4 WE 460 PAG PAG 460 460 73.2 239 27.9 >2200


4-gas compressors.pptx

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