GE-NP Proprietary Information CENTRIFUGAL COMPRESSORS Fabrizio Tani October 23rd 2001.

GE-NP Proprietary Information

CENTRIFUGAL CENTRIFUGAL COMPRESSORSCOMPRESSORS

Fabrizio Tani

October 23rd 2001


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g GEPS Oil & Gas


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The GE Portfolio of BusinessesThe GE Portfolio of Businessesg GEPS Oil & Gas


GE ResultsGE Results

Revenues Earnings($B)($B)

19971997 19981998 19991999 20002000

91 100 112130

19971997 19981998 19991999 20002000

8.2 9.310.712.7

Volume Increase as Result of Customer SatisfactionVolume Increase as Result of Customer Satisfaction

g GEPS Oil & Gas


• CompressorsCompressors

• Gas TurbinesGas Turbines

• Steam TurbinesSteam Turbines

• ReactorsReactors

• Air-CoolersAir-Coolers

• Pumps - ValvesPumps - Valves

• Metering SystemsMetering Systems

• Fuel DispensersFuel Dispensers

• High Speed Recips.High Speed Recips.

• TurboExpandersTurboExpanders• Low to Medium Low to Medium

Pressure CompressorsPressure Compressors

• Low to Medium Power Low to Medium Power Steam TurbinesSteam Turbines

• Multi-Vendor GT SvsMulti-Vendor GT Svs

Center of Excellence for...

Nuovo PignoneNuovo Pignone

RotoflowRotoflowThermodynThermodyn

GeminiGemini

OdessaOdessa

• Screw CompressorsScrew Compressors

A-C Compressor A-C Compressor

• Multi-VendorMulti-VendorCompressor ServicesCompressor Services

CONMECCONMEC

Product & Services LeadershipProduct & Services Leadershipg GEPS Oil & Gas


WHAT IS A COMPRESSOR?WHAT IS A COMPRESSOR?

COMPRESSOR

PRESSURE RATIO

GAS

Suction Pressure = PsSuction Temperature = TsSuction Velocity = Us

GAS

Discharge Pressure = PdDischarge Temperature = TdDischarge Velocity = Ud

Compressor = Black Box to increase Gas Pressure


EFFICIENCYEFFICIENCY

Ratio advantages / price

OR

Ratio cost in perfect world / cost in real world


ADIABATIC PROCESS:ADIABATIC PROCESS:

No exchange heat with external environment

First law of thermodynamics

HWQ

Adiabatic Process :

HW 0Q

TPfH ,

EnthalpyH

WorkInputW

HeatInputQ

Absorbed Power (P) = Specific Work (W) x Gas Flow (G)


A further hypothesis:

NO LOSSES

same suction conditions Ps,Ts same discharge pressure Pd lower discharge temperature Tis

The isentropic process associated to the real adiabatic process has:

ISENTROPIC PROCESSISENTROPIC PROCESS

Isentropic Process = All Energy to Compress Gas


ISENTROPIC EFFICIENCYISENTROPIC EFFICIENCY

The ratio of isentropic work to the total adsorbed energy

isisW

W

“The ratio between what we would pay to obtain a needed result in a perfect world and what we pay to obtain the same result in the real world”

Isentropic efficiency is a function of pressure ratio

vdpW

Specific Work:


TOTAL ADSORBED ENERGY

minus

ISENTROPIC WORK

LOSSES

Losses always associated to the real process

No analytical way to describe the real process point by point


Solution to control the process

isoentrope from suction conditions to

the final discharge pressure WORK INPUT ONLY

isobar at constant discharge pressure to achieve the discharge temperature HEAT INPUT ONLY


The equation define the theoretical process called POLYTROPE

For each step the isentropic work

dw vdpis

dH

vdpe

e is the constant for which the path passes through suction and discharge conditions and the isentropic efficiency of each step

We define the equation:

POLYTROPIC WORK:POLYTROPIC WORK:

The sum of all the isentropic works step by step The sum of all the isentropic works step by step

W v d ppp o l

.


POLYTROPIC EFFICIENCYPOLYTROPIC EFFICIENCY

For a perfect gas

The ratio of polytropic work to the total adsorbed energy p

pW

W

p

n

n

K

K

11

Polytropic efficiency is not pressure ratio dependant

“The ratio between the advantage we can obtain with the use of a certain tool and the price we have to pay”


CUSTOMER NEEDS

DIFFERENT POINTS OF VIEWDIFFERENT POINTS OF VIEW

MANUFACTURER NEEDS

A way to compare compressor of different manufacturers for the same service

A method to check the performance of the machine at site

Define a relationship between the performance and the geometry

Verify the performance

Achieve the performance


A WORKING IMPELLERA WORKING IMPELLER

Normally the tangential component of C1 is negligible


The radial component of gas velocity is associated to the flow

Multiply the inlet radial velocity by the area at inlet to obtain the volume flow at impeller suction

The tangential component of gas velocity is associated to the work made on the fluid

Euler equation


The energy exchanged, per unit of weight of fluid, between impeller outlet and inlet by its angular speed

EULER EQUATIONEULER EQUATION

uu CuCuW 1122

In the hypothesis that C1u is negligible

uCuW 22


EULER EQUATION

uCuW 22 Based on mechanical principles

HW

FIRST LAW EQUATION

Based on thermal quantities

W is the same!


To predict performance we need non dimensional coefficients representing a physical phenomenon that are:

DIMENSIONAL ANALYSISDIMENSIONAL ANALYSIS

Results of experimental works carried out on models of the real stages

independent of the actual size of the machine independent of the actual impellers speed independent of gas characteristics

The non dimensional coefficients are: Inlet Flow Coefficient Outlet Flow Coefficient Peripheral Mach Number Reynolds Number Head Coefficient


The ratio between the radial component of the gas velocity at inlet and impeller speed in the same point

INLET FLOW COEFFICIENTINLET FLOW COEFFICIENT

1 identifies gas angles at inlet1

11 u

C r

OUTLET FLOW COEFFICIENTOUTLET FLOW COEFFICIENTThe ratio between the radial component of the gas velocity at outlet and impeller peripheral speed

2

22 u

C rA different form const

v

v

i

o12


The ratio of impeller peripheral speed to the velocity of sound at impeller inlet:

PERIPHERAL MACH NUMBERPERIPHERAL MACH NUMBER

A measure of gas compressibility

ina

uMu 2

REYNOLDS NUMBERREYNOLDS NUMBER

ub

Re gas suction density u impeller peripheral speed b impeller exit width dynamic viscosity

It can be read as ratio of inertia forces to viscous surface forces


A measure of the impeller capacity to energise the gas

HEAD COEFFICIENTHEAD COEFFICIENTThe ratio between the tangential component of the gas velocity at outlet and impeller peripheral speed

2

2

u

C u

22uW

uCuW 22Euler equation


NON DIMENSIONAL NON DIMENSIONAL PERFORMANCE CURVESPERFORMANCE CURVES

1 f

1 gp

1 hp


Summary:Summary:Input data:• Suction Pressure• Suction Temperature• Gas Composition• Discharge Pressure

Status Equation (BWRS: Benedict Webb Rubin Starling)

Experimental data:

• Flow Coefficient• Head Coefficient

• Discharge Pressure• Absorbed Power• Efficiency


Main Design Criteria of Main Design Criteria of CompressorCompressor- Efficiency: • 84 - 87 % for compression ratio up to 2• more than 75 % for compression ratio above 2

- Operating range: from 70 to 140 % of the design point

Design Point


LNGLiquefied Natural Gas

NATURAL GAS• Oil Production• Gas Production• Gas Lift•Pipeline• Gas Re-injection• Gas Storage

PETROCHEMICALS• Syngas & Fertilizers:

CO2 compressor for UREA Plants Ammonia Synthesis Methanol Synthesis

REFINERY• Fluid catalytic cracking• Reforming• Hydrocracking

Manufacturing Complete Range of Centrifugal Compressors

A comprehensive production for On-Shore and Off-Shore Services since 1960from the High Volumes - Low Pressure Applications

to the Low Volumes - High Pressure Applications

Over 3500 Units SoldOver 3500 Units SoldWorld Leader in Gas CompressionWorld Leader in Gas Compression

Over 3500 Units SoldOver 3500 Units SoldWorld Leader in Gas CompressionWorld Leader in Gas Compression


Low Pressures - High Volumes


MCL - 2MCL - 3MCL - DMCL Compressors

• High Volume Flows [up to 200,000 m3/h for MCL - 300,000 m3/h for DMCL]

• Low Discharge Pressures [up to 40 bar]

• Casings either cast or fabricated

• Cast Iron Diaphragms

• Radial and Thrust Bearings Tilting Pad type

• Shaft End Seals both Oil film type or dry gas seal type

Low Pressures - High Volumes


Casings and Diaphragms for High Pressure CompressorsCasings and Diaphragms for High Pressure CompressorsCasings and Diaphragms for High Pressure CompressorsCasings and Diaphragms for High Pressure Compressors

GE-NP Proprietary InformationGE-NP Proprietary Information

BCL (/N-/A-/B-/C-/D) - 2BCL (/N-/A-/B-/C-/D) - 3BCLCompressors for casing rating ranging up to 15000 Psi (API)

• Medium to Low Volume Flows [ranging from 80,000 m3/h down to 300 m3/h]

• Medium to Very High Discharge Pressures [experienced up to 700 bar]

• Forged Steel Casings

• Forged Steel Inner Casing

• Cast Iron Diaphragms (forged steel for high differential Pressures)

• Radial and Thrust Bearings Tilting Pad type

• Shaft End Seals both Oil film type or dry gas seal type

High/Very High pressures - Low Volumes

GE-NP Proprietary InformationGE-NP Proprietary Information

Overhung TypeBeam Type

• Axial Inlet

• Sin gle Impeller

• High Volumes, Low Pressure Ratio

• Hyd rostatic Lift

• Size 800 to 1000

• Lateral Flanges

• On e to Three Impel lers

• High Pressure Ratio

• Axial Thrust Balance

• Sizes 300 to 1000

Gas Pipeline Compressor - PCL


3D Impeller Technology Machined by 5-Axis Milling Machines

Barrel Casing With Cartridge Concept Internalsfor Easy Maintenance


Vertically Split Pipeline Compressors

• Medium to High Volume Flows [ranging from 80,000 m3/h down to 3000 m3/h]

• Low to Medium Discharge Pressures [experienced up to 110 bar]

• Low Compressor Ratio [experienced up to 2]

• High Polytropic Efficiency [experienced up to 0.86 with vaned Diffusor]

• Axial Gas Inlet Arragement or Traditional Side Inlet Flange Configuration

• Forged Steel Casings and inner casing

• Radial and Thrust Bearings Tilting Pad type (option for magnetic bearings)

• Shaft End Seals with Tandem Dry Gas Seals

• Standardized casings for one to three impellers and direct coupling to NP Gas Turbines

Gas Pipeline Compressor - PCL


Compressor SelectionCompressor Selection

The compressor is normally driven by Gas Turbine or Electric Motor

Compression selection steps:

• Estimated absorbed power with dedicated software• Selection of the suitable GT model• Rotating speed becomes an input, related to the selected GT• Final selection of compressor by specific software

Compressor Configurators are the E-tools to perform a selection via INTERNET


STAGES STANDARDIZATIONSTAGES STANDARDIZATION

• Predesigned and tested stages are used to meet Predesigned and tested stages are used to meet the requested performance and to avoid rotating the requested performance and to avoid rotating stall on statoric and rotating componentsstall on statoric and rotating components

Standardization Ensures Reliability of Predicted PerformancesStandardization Ensures Reliability of Predicted PerformancesStandardization Ensures Reliability of Predicted PerformancesStandardization Ensures Reliability of Predicted Performances


EXPERIENCED UP TO 210 BAR STATICEXPERIENCED UP TO 210 BAR STATIC

TANDEM SEALSTANDEM SEALS

TRIPLE SEALSTRIPLE SEALS

EXPERIENCED UP TO 290 BAR DYNAMIC AND 310 BAR STATICEXPERIENCED UP TO 290 BAR DYNAMIC AND 310 BAR STATIC

Shaft end sealingShaft end sealing


Shaft end sealingShaft end sealing

Nuovo PignoneNuovo PignoneLARGE EXPERIENCE ON DRY GAS SEALSLARGE EXPERIENCE ON DRY GAS SEALS

Over 200 Compressors with Dry Gas SealsOver 200 Compressors with Dry Gas Seals

Sealing pressures at Settling Out conditions Sealing pressures at Settling Out conditions up to 4200 PSIAup to 4200 PSIA

Dry Gas Seals size up to 250MMDry Gas Seals size up to 250MM

Dry Gas Sealing system for 2BCL306CStatoil Veslefrikk Compressor


•HONEYCOMB labyrinthsHONEYCOMB labyrinthson balancing drums and impellers on balancing drums and impellers

to increase rotor system damping capabilitiesto increase rotor system damping capabilitiesfor High Pressure Applicationsfor High Pressure Applications..

Honeycomb for Improved Rotor StabilityHoneycomb for Improved Rotor StabilityHoneycomb for Improved Rotor StabilityHoneycomb for Improved Rotor Stability


Propane Compressor installed at Bintulu Plant

GE-NP Proprietary Information CENTRIFUGAL COMPRESSORS Fabrizio Tani October 23rd 2001.

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Transcript of GE-NP Proprietary Information CENTRIFUGAL COMPRESSORS Fabrizio Tani October 23rd 2001.