Fuel Gas Booster Compressors

Fuel Gas Booster Compressors

2< >MAN Diesel & Turbo Fuel Gas by MDT - Athens 2014 02.10.2014


MDT fuel gas booster compressors

are of integrally-geared design to API 617 Chapter 3


Fuel Gas Booster CompressorsTypical Gas Turbine Requirements and Compressor Configurations

Large gas turbines require fuel gas pressure levels such as:

• 45…50 bar, typical for Trent, GT24 and GT26 gas turbines

• 33…36 bar, typical for 9FA/B and Siemens gas turbines

•40…46 bar, typical for MHI gas turbines

• < 30 bar for Ansaldo gas turbines and older models or small size GTs

With gas pipeline pressure levels ranging from max. 80 to as low as 3-4 bar, many installations require fuel gas booster compressors.

Depending on the overall power plant concept, typical combinations are:

• 1x100% gas compressor for backup service w/ usually high pipeline pressure

• 2x100% for maximum availability

• 3x50% for multiple unit power stations

•any other combination as the case may be (such as 5x100%)



MDT gas booster compressors are of integrally geared design as per API 617 chapter 3

They are arranged as single lift packages on a steel base frame with externally installed gas cooler

All on skid piping and wiring is brought to skid edge for easy connections

Integrally geared compressors



MDT’s integrally geared type compressor range

1- to 6-stage gear-type compressors for up to 60 bar discharge pressure

and beyond for other applications

Single stage gas compressor package for a power plant in Al Jubail, Saudi Arabia

6-stage gas compressor for gas transport in Canada, oil sands

Fuel Gas Booster Compressors Product Range



1-, 3- und 5-stage compressor packages for different

configurations and applications

Other Examples



Coupling shaft

Bull gear

Compressor casing / volute

Inlet guide vanes(IGV)

IGV actuator

Gearbox casing

Pinion shaft

Impeller

3D sectional view



The gear is a single helical type with thrust collars on the pinion shafts.

Gear



The compressor casing (volute) is of cast steel

Stationary parts - Casing


Fuel Gas Booster CompressorsRotating parts - Impellers

Impeller designs range from milled open type to milled and brazed closed impellers of 2D or 3D type



The Hirth toothing is a form-fitted connection with a high repeatability precision of 0.0001 mm.

No repeated balancing required after re-assembly.

Rotating parts - Impeller to shaft assembly



Assembled shaft with two impellers after balancing

Rotating parts - Shaft assembly



PROCESS ATMOSPHERE

Clean Buffer GasLeakage Inert Buffer Gas

Inert Buffer Gas

Source: Flowserve

The compressor stage(s) will be sealed towards the atmosphere by dry gas seal cartridge(s), tandem type with intermediate labyrinth

Seals



Compressor Design Data

(Input for Compressor Design)



Typically, integrally geared gas compressors are characterized by relatively low flow and high head (high pressure ratio) combinations.

Basic design data for the fuel gas compressors:

• configuration, e.g. …x 100%

• rated flow = … Nm³/h

• inlet pressure = xx – yy barg (min. / max., yes/no suction pressure control)

• inlet temperature = xx – yy °C

• outlet pressure = xx barg

• max. allowable gas temperature (for cooler arrangement)

• gas composition = mol-weight xx kg/kmol, estimate or analysis

• contaminations, such as H2S, mercaptans, etc. (NACE design)

• driver preference and control mode options (VFD, inlet guide vanes, throttle)

Design Input Information



Compressor Type Selection

(Design Output Data)


Fuel Gas Booster CompressorsPerformance Map (pressure vs flow)

Design point

Operating range (IGV)Surge control line


Fuel Gas Booster CompressorsPerformance Map (power vs flow / IGV angles)

Design point

Rated motorpower



High efficiencyintegral gearaxial inflow to each stageoptimum flow coefficients (speed selection)small hub/tip ratiosadjustable inlet guide vanesintercooling after each stage

Low investment

Wide application rangeshrouded / unshrouded impellers etc.connects the benefits of high- and low-speed trains

Advantages of Integrally Geared Compressor Design



Design details



The process conditions suppose a single-stage integrally geared design compressor to API 617 7th edition.

Mechanical design limits (mainly power vs. speed) are considered in the design of the gearbox and its bearings.

Combination of pinion shaft speed and max. power are well within the experience limits.

The compressor casings (volute) will be made of cast steel G20Mn5.

Impeller material will be X13CrMoV, alternatively aluminum may be used for rotor-dynamic reasons.

The impeller will be milled design, open type.

Proposed design: integrally geared compressor



Typical 3-stage gas compressor package

Base frame w/ integrated oil reservoir

Stage 1 inlet flange

Oil system piping

Seal gas rack

Motor



Typical 3-stage gas compressor package

Stage 3 outlet flange

Inter-stage pipe spools

Oil heater

Seal gas piping

Double oil filter MV motor terminal box



Hamburg

BerlinOberhausen

Zürich

Manufacturing, packaging and testing in Oberhausen:Axial compressors Large centr. compressorsSteam turbinesGas turbinesScrew compressorsAll kind of testing

Manufacturing and packaging in Berlin:Small centr. compressorsManufacturing of all radial compressor stages

Testing of compressors in Zürich:Compressor packages are scheduled to be tested in the Oberhausen test center, with back-up capacity in the Zurich test fields

MDT’s European turbo manufacturing facilities



Package Examples


Fuel Gas Booster CompressorsExamples (1)



This picture shows a packaged 3-stage compressor ready to go to site.

Examples (2)



Installation Examples



Buidling for 2 gas compressors and auxiliary equipment in Castejon, Spain.

Installations (1)



Shelter for 2 gas compressors and auxiliary equipment in Boehlen, Germany.

Installations (2)



Outdoor installation with completely enclosing outdoor noise hoods in St. John, Canada

Installations (3)



Maintenance



This means operators can expect 5 years uninterrupted operation!

Maintenance requirements



All data provided in this document is non-binding. This data serves informational purposes only and is especially not guaranteed in any way. Depending on the subsequent specific individual projects, the relevant data may be subject to changes and will be assessed and determined individually for each project. This will depend on the particular characteristics of each individual project, especially specific site and operational conditions.

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Fuel Gas Booster Compressors