Laby®-GI

BOG Compression for MAN Diesel's ME-GI Dual Fuel Propulsion System (DFDM) and FLNG Offshore Applications

MAN Diesel ME-GI dual fuel propulsion system (DFDM)
The Laby®-GI was designed for MAN Diesel's ME-GI dual fuel propulsion system (DFDM) for LNG carriers. Due to various reliquefaction options the BOG can either be used as fuel or it can be liquefied and returned to the tanks.

Offshore applications FSRU, LNG FPSO and LNG RV
The fully balanced design, resulting in the elimination of unbalanced forces and moments, enables us to offer this new type of compressor for other fields of applications that have high requirements in terms of vibrations. Such applications include FSRU, LNG FPSO and LNG RV where the deck structure significantly affects the compressor specifications.

Ease of operation and maintenance
Due to the noncomplex compressor system the operation and maintenance can be easily carried out by low qualified crews and maintenance staff. Thus, maintenance and operation costs are minimized.

Highest reliability and availability
Our references in LNG and offshore applications, the type approval process and the experience in engineering and manufacturing reciprocating compressors state the high safety level and the outstanding reliability and availability of the system.

"Economic BOG Handling Solutions for FLNG Applications" LNG Tech Global Summit 2009, Rotterdam: by Rainer Dübi (1095kB)

Offshore sector logs first labyrinth piston compressor order
Article published in LNG World Shipping Nov/Dec 2008 issue (129kB)

Gas-injected diesels next on MAN agenda
Article published in LNG World Shipping Aug 2008 issue (396kB)

Laby®-GI compressor developed for LNG carrier service
Article published in CompressorTechTwo Sept/Aug 2008 issue (378kB)

Fuel Gas Compression and Excess Boil-off Gas Reliquefaction for Dual Fuel LNG Carriers (338kB)

LNG carrier with ME-GI engine, high pressure compressor and boil-off gas reliquefaction system (1339kB)

Performance

Compressor type	4LP250	6LP250
Suction pressure [bar abs] / [psi]	1.03 to 1.17 / 14.9 to 16.9	1.03 to 1.17 / 14.9 to 16.9
Discharge pressure [bar abs] / [psi]	up to 350 / 5070	up to 350 / 5070
Suction temperature [°C / F]	-170 to 45 / -270 to 113	-170to 45 / -270 to 113
Flow [kg/h] / [lbs/h]	2000 to 4500 / 4400 to 9900	4500 to 13000 / 9900 to 26800

Design features

No vibrations due to elimination of unbalanced forces and moments caused by rotating masses
Increased lifetime and reduced wear resulting in lowest maintenance costs due to the labyrinth sealing system (contact-free and non-lubricated) on piston and piston rod gland in the cryogenic area
Less wear caused by weight forces due to vertical piston rod guiding arrangement
Quick start-up with suction temperatures down to minus 170°C (minus 250F) because there is no pre-heating of the gas or pre-cooling of the compressor required
Long lifetime with top performance due to in-house engineered, top quality compressor components
No gas losses thanks to the gastight design
Quick and easy installation thanks to skid mounting
All applied components have been successfully operated in LNG applications for long periods

ME-GI:

Gas flexibility: the occurring BOG can either be used as fuel gas or it can be returned to the tanks after the optional, parallel arranged reliquefaction plant
Fuel flexibility: full capacity control range from 0% to 100% for optimal natural gas adjustment
Long lifetime of high pressure components due to the utlisation of proven lubricant systems

Applications

Fuel gas injection for the ME-GI dual fuel propulsion system (DFDM) from MAN Diesel with parallel reliquefaction options
Fuel gas injection for gas turbines on LNG FPSO
Minimum send-out compressor on FSRU
Many more

Gases handled

LNG BOG
Natural gas
Hydrocarbon gases, such as ethylene