The 4T50ME-GI Test Engine at MAN Diesel & Turbo's ... - Sae.org

The 4T50ME-GI Test Engine 

at MAN Diesel & Turbo’s 

Diesel Research Centre Copenhagen

Content 

MAN B&W Diesel 

1 Introduction ..............................................................................................6 

2 The Test Facility.........................................................................................7 

The research engine – 4T50ME-X ............................................................7 

Application of the research engine ...........................................................7 

3 Reciprocating Internal Combustion Engines on Gas Fuel ............................9 

4 ME-GI Concept and Engine Design ......................................................... 10 

Design concept ................................................................................... 10 

Fuel Injection Valves .............................................................................. 10 

Cylinder Cover ...................................................................................... 11 

Gas Block............................................................................................. 11 

Gas Pipes ............................................................................................. 12 

Fuel Oil Booster Unit ............................................................................. 13 

Exhaust Receiver .................................................................................. 13 

Planned Tests ....................................................................................... 13 

5 ME-GI gas supply system ........................................................................ 14 

Layout of test-bed arrangements: ......................................................... 14 

Cryogenic storage tank: ........................................................................ 15 

Cryogenic reciprocating pump: ............................................................. 15 

Vaporiser and glycol water heating system: ........................................... 15 

Gas-pressure control: ........................................................................... 15 

Gas train .............................................................................................. 16 

Double-wall gas pipes ........................................................................... 16 

N 2 purging system: ............................................................................... 17 

Control and safety system: .................................................................... 17 

6 Test Program .......................................................................................... 17 

7 Potential Applications for ME-GI Engines ................................................. 18 

Conclusion ................................................................................................. 18 

The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s Copenhagen Test Centre 

4

The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s 

Copenhagen Test Centre 

1 Introduction 

The commercial operation of two- 

stroke, low-speed diesel engines us- 

ing natural gas as a fuel source aboard 

ships has been a dream and even an 

obsession for decades. 

The high efficiency and unrivalled relia- 

bility of such engines, together with the 

widespread availability of an onshore 

gas-distribution network since the 

1930s, triggered the development and 

application of such engines for power 

generation in the United States. 

At the 1983 CIMAC congress in Paris, 

Mitsui Engineering and Shipbuilding re- 

launched the concept by proposing a 

low-speed K80GIDE, also referred to as 

a K80MC-GI, a low-speed diesel engine 

based on the MAN B&W K80MC. This 

was adapted for high-pressure gas in- 


jection (GI), and was particularly aimed 

at replacing the rather energy-inefficient 

steam turbines used for LNG carrier 

propulsion. 

At the time, both the gas-vs-fuel price 

development, as well as technical and 

political reluctance, prevented the idea 

from being commercially successful. 

However, technically, the concept was 

fully proven on the test bed and, com- 

mercially, as a prime mover in the Chiba 

power plant in Japan. 

In more recent times, development has 

taken new turns with environmental 

considerations having changed from 

being interesting to becoming a neces- 

sity. Furthermore, diesel engines have 

now entered the propulsion market for 

LNG carriers en masse and gas engines 

are on the verge of being adopted for 

propulsion by other ship types. 

Accordingly, MAN Diesel and Turbo 

Denmark took the decision in 2010 to 

build a full-scale test and demonstration 

engine at its R&D centre in Copenha- 

gen. This intends to clear the way for 

the full-scale commercial adoption of 

the now electronically-controlled, dual- 

fuel, low-speed, two-stroke ME-GI die- 

sel-engine range. 

This paper outlines the building of the 

engine, the design and layout of its gas- 

supply system and its test programme. 

It also discusses the ME-GI engine’s 

position in the market as one of several 

solutions capable of meeting the IMO’s 

Tier-III emission regulations, scheduled 

to come in force for newbuildings from 

January 1, 2016. 


6

2 The Test Facility 

The MAN Diesel & Turbo research cen- 

tre in Copenhagen was inaugurated 

in 1992. Its centrepiece is a specially- 

designed, two-stroke, four-cylinder re- 

search engine, which plays an impor- 

tant role in the development of MAN 

B&W two-stroke diesel engines. The re- 

search engine has logged almost 8,500 

hours in operation since 1992 and hosts 

many, different type tests, from basic 

research – for example, into materials, 

tribology, and combustion theory – to 

testing and verification of engine con- 

trol systems and type-approval testing 

(TAT). In recent years, the research en- 

gine has also been applied on a large 

scale for the testing of emission-reduc- 

ing systems, such as EGR (exhaust gas 

recirculation) and scrubbers. 

In 1997, the research centre was ex- 

panded to include additional test rigs 

for the simulation of engine sub-com- 

ponents. The test rigs allow the rapid 

testing and development of concepts 

and systems in a safe environment 

without risking any damage to the en- 

gine. This ensures a certain degree of 

product maturing before installing the 

systems on, for example, the research 

engine, thereby saving service time on 

the engine. More and more test rigs 

have been added over the years. 

The research centre was extended 

once again in 2010 where a third floor 

with new office facilities, a new engine- 

control room, and a new emission- 

measuring room was added. From the 

offices, the R&D engineers have direct 

access to the engine-control room. 

The research engine – 4T50ME-X 

The research engine has four cylinders 

of 50-cm bore and a stroke of 2,200 

cm, generating 7,080 kW at 123 rev./ 

min. 

7 The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s Copenhagen Test Centre 

Fig. 1: MAN Diesel & Turbo research centre in Copenhagen 

Test engine specification – 4T50ME-X 

Engine type Diesel, two-stroke 

No. of cylinders 4 

Bore 50 mm 

Stroke 2,200 mm 

Power 7,080 kW 

Max. speed 123 rpm 

Application of the research engine 

The research engine is utilised for a 

wide range of research tests. These 

tests are characterised by the fact that 

they cannot be carried out elsewhere, 

for example, on an engine-builder’s 

testbed or aboard a vessel in service. 

Furthermore, many tests require highly 

controlled conditions to ensure a high

eliability while the large volume of data 

typically acquired from the extensive 

measuring set-ups make the test centre 

an eminently suitable test venue. 

The test centre has also added spe- 

cial adjustment options to ensure valid 

measurements, for instance, the intake 

air temperature can be adjusted very 

precisely, for example, to enable ISO 

conditions. 

Other tests involve risks, such as pro- 

voked breakdowns or the testing of 

control failures. 

Fig. 2: Research engine in ME-GI configuration 


Other examples of research tests in- 

clude: 

Oil-film measurements in bearings 

testing of piston rings 

material testing, e.g. for liners 

SFOC / emission optimisation 

various combustion studies 

testing of subcomponents 

testing of monitoring systems and 

safety systems, e.g. oil mist detector 

emission control systems 

turbochargers 

engine control systems 

ECS TAT tests for class societies 

The test centre engine’s special desig- 

nation (ME-X) is an indication of its hy- 

brid engine control design, which, over 

its lifetime, has frequently changed. 

Currently, the following configurations 

are possible: 

1. ME: 100% electronically-controlled 

engine with hydraulically-actuated 

exhaust valve and fuel injection. 

2. ME-B: electronically-controlled en- 

gine with hydraulically-actuated fuel 

injection and simulated mechanically- 

actuated exhaust valve. 

3. ME-GI - ME engine with Gas Injection 

(see Fig. 2). 


8

3 Reciprocating Internal Combustion 

Engines on Gas Fuel 

Different principles have been used to 

operate reciprocating internal-com- 

bustion engines on gas. The two main 

types are: 

Premixed combustion in an Otto- 

type cycle. This principle is similar 

to a normal gasoline (or Otto) engine, 

where low-pressure gas is mixed with 

the fresh charge prior to entering the 

cylinder. The gas-air mixture then en- 

ters the combustion chamber and is 

compressed. The ignition of the mix- 

ture is controlled either by a spark 

plug at the top of the combustion 

chamber, by a pre-ignition chamber, 

or by injecting easily ignitable fuel via 

a separate pilot-fuel injection system. 

The gas-air mixture is subsequently 

burned in a pre-mixed mode and the 

heat release carries out its mechani- 

cal work on the piston. Too early 

self-ignition and misfire of the mixture 

leads to knocking that can destroy 

the engine mechanically. The ignita- 

bility of the mixture is highly depend- 

ent on the mixture composition and 

gas species, and hence a function of 

the type of gaseous fuel. Since the 

knocking regime must be avoided 

with some safety margin, this effec- 

tively limits the possible engine com- 

pression ratio and maximum cylinder 

pressures and hereby places a limit 

to the obtainable energy efficiency. 

The Diesel Gas Engine. This fea- 

tures a high-pressure gas injector 

that injects gas into the compressed 

charge. Gas and fresh, compressed 

air mix in the jet and burn immedi- 

ately in a turbulent, non-premixed 

jet flame. The ignition of the mixture 

is usually ensured by employing a 

second injector for small amounts of 

easily ignitable fuel, such as ordinary 

diesel oil. The system has high fuel 

flexibility as all, common diesel fuels 

may be used from the pilot system 

without the use of the gas injec- 

tors. In gas mode, the principle is 

very robust for variations in the gas 

mixture and can make use of virtu- 

ally any gaseous fuel. Since misfire is 

not possible (the gaseous fuel is in- 

jected when combustion has already 

started and not before), compression 

rates and cylinder pressures are not 

limited by a knocking condition and 

hence higher energy efficiency can 

be obtained. 

Today, marine, low-speed, two-stroke, 

diesel engines are the de-facto stand- 

ard for the propulsion of commercial 

vessels. This is due to their straightfor- 

ward installation with a direct coupled 

propeller, high efficiency, ability to burn 

HFO, simple design, low maintenance 

costs and, not least, reliability. 

Current trends suggest that the price 

of LNG per energy unit will become 

lower than that of HFO and significantly 

lower than for MDO and MGO. Further- 

more, the recent, giant expansion of 

LNG transport worldwide will present 

opportunities for the establishment of 

LNG bunkering stations at strategic lo- 

cations. 

The ME-GI concept, operating accord- 

ing to the second principle of a diesel 

gas engine, will retain all of the previ- 

ously mentioned features of the two- 

stroke propulsion machinery and, si- 


multaneously, allow the possibility of 

using LNG as a fuel whenever beneficial 

from an economic or emission point of 

view. 

The engine designer developing a gas- 

injection diesel engine must develop a 

gas-injection system together with an 

additional injection system for small 

amounts of diesel fuel (the so-called pilot 

injection) in order to ensure a safe igni- 

tion at all operating points. This requires 

an entirely new system for engine con- 

trol and monitoring that not only needs 

to be designed, but also optimised for 

different operating conditions. Due to 

the poor ignition properties of natural 

gas, the cylinder processes need to be 

monitored continuously with a system 

of sensors and electronics that require 

calibration during engine operation. 

Furthermore, the control system must 

be able to deal effectively with the un- 

certainty of the actual gas properties 

to be able to continuously optimise the 

fuel efficiency. The lack of sulphur in the 

natural gas, although beneficial from an 

environmental point of view, leads to tri- 

bological challenges, because sulphur 

components generally have very good 

lubrication properties. The change of 

fuel to natural gas not only involves 

changes to the engine, but requires the 

development of guidelines and rules on 

how to install tank and distribution sys- 

tems for natural gas aboard ships.

4 ME-GI Concept and Engine Design 

Design concept 

The test system consists of an LNG 

tank, a fuel-gas supply unit that, as is 

the case aboard a vessel, are located 

outside the building/engine room. 

Inside the building, the NG gas, sup- 

plied at a pressure of 250-300 bar 

and 45 deg C, is led to the cylinders 

through a double-wall pipe system. A 

gas-injection control block is mounted 

on each cylinder cover. In parallel with 

the inlet pipe, there is a similar, double- 

wall pipe for discharging all NG when 

the gas system is shut down and emp- 

tied by N2 purging. 

At all points where a gas leak from the 

system to the engine room could poten- 

tially occur, the gas is collected in a ven- 

tilated buffer space which is monitored 

by HC sensors. 

Head – Gas valve 

Fig. 3: Gas injection valve 


Housing 

The ME-GI concept maintains the full 

functionality of the existing, HFO-burn- 

ing, two-stroke engine. The GI system 

is, so to say, an add-on system giving 

an additional operation mode where the 

LNG can be used as fuel simultaneously 

with diesel or heavy fuel oils and at al- 

most any ratio. 

In the following sections of this paper, 

the ME-GI system is described, starting 

where the gas is injected into the com- 

bustion space, and ending where the 

gas enters the engine room. 

Fuel Injection Valves 

Dual-fuel operation requires valves for 

injection of both pilot fuel-oil and gas 

fuel. Two separate valves types are used 

with two fitted for gas injection and two 

for pilot fuel-oil. The pilot fuel-oil valve 

is a standard fuel-oil valve without any 

changes. Therefore, it is also possible 

to run the engine at 100 % MCR on fuel 

oil – HFO as well as MDO. 

O-ring 

Sealing ring 

Spring 

Spindle 

Gas enters the gas-injection valve 

through bores in the cylinder cover. To 

prevent gas leakage between the cyl- 

inder cover and the gas-injection valve 

– as well as between the valve hous- 

ing and the spindle guide – sealing rings 

made of temperature- and gas-resistant 

material are installed. Any gas leakage 

through the gas-sealing rings is led 

through bores in the gas-injection valve 

to the double-wall gas piping system, 

where any gas leakage is detected by 

HC sensors. 

The gas acts continuously on the valve 

spindle at a pressure of about 250-300 

bar. In order to prevent the gas from en- 

tering the control-oil activating system, 

the spindle is sealed by means of seal- 

ing oil led to the spindle clearance at a 

pressure higher than the gas pressure 

(15 bar higher). 

Holder 

Spindle guide 

Nozzle 


10

Cylinder Cover 

The cylinder cover has a face for the 

mounting of the gas control-block (de- 

scribed further on) and is provided with 

a set of bores, which are for supplying 

gas from the gas control-block to both 

gas injection valves (see Fig. 4). 

The cylinder cover is provided with an 

Inconel cladding in the area with the 

highest thermal load. 

Gas injection valve 

Fig. 4: Cylinder cover for ME-GI 

Gas Block 

The gas control-block incorporates an 

accumulator provided with a windows/ 

shut-down valve and two purge valves. 

All high-pressure gas sealings lead 

into spaces that are connected to the 

double-wall pipe system for leakage de- 

tection. The gas is supplied to the ac- 

cumulator via a non-return valve placed 

in the connection piece. From the ac- 

cumulator, the gas passes through 

a bore in the gas control-block to the 

window/shut-down valve, which in the 

gas mode is opened and controlled by 


Face for gas block 

Pilot / fuel oil 

injection valve 

Indicator valve 

Face for gas block 

the MPC. The window/shut-down valve 

also includes a feature that prevents 

gas injection in the combustion cham- 

ber at any inappropriate point of the 

engine stroke. From the gas window/ 

shut-down valve, the gas is led to the 

gas-injection valve via bores in the gas 

control-block and the cylinder cover. 

Blow-off/purge valves are designed to 

pressure-release the gas bores when 

needed, as well as to empty the accu- 

mulator when the engine is no longer to 

operate in gas mode (see Fig. 5).

Gas block 

ELGI valve 

Purge & blow-off 

valve 

Fig. 5: Gas control block 

Fig. 6: ME-GI piping 


Control 

valves 

Gas inlet 

O-rings 

Connection piece 

Cylinder cover 

Sealing rings 

Window / shut down valve 

Gas control block 

Gas accumulator volume 

Connection pipe 

Non return valve 

Gas Pipes 

A common-rail (constant pressure) sys- 

tem is to be fitted for high-pressure gas 

distribution to each gas-control block. 

The gas pipes are designed with dou- 

ble walls, with the outer shielding pipe 

designed to prevent gas outflow to 

the machinery spaces in the event of 

the rupture of the inner gas pipe. The 

intervening space, including also the 

space around valves, flanges, etc., is 

equipped with separate mechanical 

ventilation with a capacity of approx. 

30 air-changes per hour. The pressure 

in the intervening space is below that 

of the engine room and (extractor) fan 

motors are placed outside the ventila- 

tion ducts, and the fan material must be 

manufactured from spark-free material. 

The ventilation inlet air must be taken 

from a gas-safe area. 

The double-wall piping system is de- 

signed so that every part is ventilated. 

However, tiny volumes around the gas- 

injection valves in the cylinder cover are 

not ventilated by flowing air for practical 

reasons. Small gas amounts, which in 

the event of leakages may accumulate 

in these small clearances, blind ends, 

etc. cannot be avoided, but the amount 

of gas is negligible. Any other gas leak- 

ages are led to the ventilated part of the 

double-wall piping system and detect- 

ed by the HC sensors. 

The gas pipes on the engine are de- 

signed for a pressure 50% higher than 

normal working pressure, and are sup- 

ported to avoid mechanical vibrations. 

The gas pipes should furthermore be 

protected against heavy items being 

dropped upon them. The pipes are 

pressure tested at 1.5 times the work- 


12

ing pressure. The design is to be all- 

welded as far as practicable, with flange 

connections only present for servicing 

purposes as far as practicable. 

The branch piping to the individual 

cylinders must be flexible enough to 

cope with the thermal expansion of the 

engine from cold to hot states. Fig. 7 

shows a principle design of the branch- 

ing of the main pipe, which follows the 

demands described here. 

Fig. 7: Branch pipe concept 

The gas-pipe system is also designed 

so as to avoid excessive gas-pressure 

fluctuations during operation. 

Finally, gas pipes are connected to an 

inert, gas-purging system. 

Fuel Oil Booster Unit 

Dual-fuel operation requires a fuel-oil 

pressure booster, a position sensor, a 

FIVA valve to control the injection of pi- 

lot oil, and an ELGI valve to control the 

injection of gas. 

The ME fuel-oil pressure booster is a 

standard ME pressure booster with a 

pressure sensor added for checking 

the pilot-oil injection pressure, which is 

used to monitor the fuel-oil valves. The 

amount of pilot-oil injected is monitored 

by the position sensor. 

The volume of gas injected is control- 

led by the duration of control-oil delivery 

from the ELGI valve. The operating me- 

dium is the same control /servo oil as 

used for the fuel-oil pressure booster. 

Exhaust Receiver 

The exhaust-gas receiver is designed to 

withstand the pressure in the event of 

ignition failure of one cylinder followed 

by ignition of the unburned gas in the 

receiver. For the S60ME-GI, this means 

that the shell thickness and deep- 

dished head thickness has increased 

from 10 mm to 13 mm; the fix-support 

Sealing oil pipes 

Control oil pipes 

Fig. 9: Gas control block and cylinder cover for the test rig 


plate increases from 25 mm to 28 mm. 

Reinforcement rings need to be adapt- 

ed for the turbocharger and exhaust 

pipes and the compensators have to be 

able to withstand a static pressure of 20 

bar at 20ºC. 

Planned Tests 

A gas-test rig has been produced for 

operation on air in order to finalise the 

design by checking the function of the 

gas control-block, the gas-injection 

valves and the gas window/shut down 

valve. It consists of the gas control- 

block, a cylinder cover with the gas-in- 

jection valves, and a PLC for controlling 

the test rig. Comprehensive tests on 

this rig were performed during the win- 

ter of 2010-2011 (see Figs. 9 and 10). 

Gas injection valve 

Cylinder cover 

Gas control block

5 ME-GI gas supply system 

This is a short description of the com- 

ponents and systems involved in a gas- 

supply system based on pressurising 

LNG with a high-pressure, cryogenic 

pump and then vaporising the gas be- 

fore supply to the ME-GI gas-injection 

system. 

The high-pressure (natural) gas required 

by the engine can be provided by either 

reciprocating compressors working 

on evaporated gas, for example, from 

a pipeline, or by a cryogenic system 

working from an LNG network. For our 

purposes, the cryogenic system is most 

feasible. 

The system must be suitable for the 

supply of fuel to both test-bed installa- 

tions at an engine builder and aboard 

an LNG carrier with reliquefaction of 

BOG, as well as aboard non-LNG carri- 

ers with an LNG tank installed at a suit- 

able place in the hull. 

The following items are required for the 

ME-GI gas supply system: 

layout of test bed arrangements 

cryogenic storage tank 

cryogenic reciprocating pump 

vaporiser and glycol water-heating 

system 

gas-pressure control 

gas train 

double-wall gas pipes 

N2 purging system 

control and safety system 

Layout of test-bed arrangements: 

The ME-GI gas-supply system consists 

of a cryogenic storage tank, a high- 

pressure cryogenic pump, a pulsation 

damper, a vaporiser and a gas-flow/ 


MPC unit 

Fig. 10: Gas test rig 

LNG tank 

27,000 l 

Gas (air) supply unit Cylinder cover 

PLC control unit 

High pressure pump 

KPL 36/80VGS1 

M 

Cool down and mini flow line 

Fig. 11: The ME-GI gas-supply system 

pressure-control system. A system de- 

sign could possibly look like this: 

The ME-GI gas-supply system should 

be placed outside, marked as a hazard- 

Control and seal oil unit 

Gas control block 

NG Damper 

PC PC 

LNG Vaporizer 

ME-GI 

ous zone, and protected against poten- 

tial collisions. 


14

Fig. 12: Example of cryogenic tank design 

Cryogenic storage tank: 

The cryogenic storage tank is designed 

as an inner, stainless-steel vessel within 

an outer steel vessel. A vacuum is ap- 

plied between the vessels to provide 

sufficient insulation such that it can 

withstand temperature increases over a 

longer period of time (up to four weeks, 

depending on tank pressure). The tank 

pressure could be 2 to 2.5 bar, depend- 

ing on the cryogenic-pump suction- 

pressure requirements. The cryogenic 

tank is equipped with safety valves with 

an opening pressure depending on de- 

sign layout. 

The cryogenic tank is supplied with 

LNG delivered by a lorry tanker. 

Cryogenic reciprocating pump: 

The cryogenic reciprocating pump is 

supplied with LNG from a storage tank 

connected by a vacuum-insulated pipe, 

ensuring the supply of liquefied gas. The 

cryogenic pump could be an vacuum- 

insulated piston-pump type coupled to 

a variable-speed motor suitable for con- 

tinuous operation as well as cold stand- 

by. A suction filter is integrated into the 

pump head. The cryogenic-pump pres- 

sure and flow is controlled by the vari- 

able-frequency pump motor. The pres- 

sure set-point is taken from the ME-GI 

control system with a range from 150 

to 300 bar. The cryogenic pump must 

be equipped with a pulsation damper in 

order to achieve gas-pressure fluctua- 

tions within 0.3 bar. 

Fig. 13: Gas train 


Vaporiser and glycol water heating 

system: 

The vaporiser is connected to the 

cryogenic-pump outlet and the LNG 

is heated with a glycol-water system. 

Alternative heating medias as engine- 

cooling water or ambient-temperature 

vaporisers could be utilised, but a gly- 

col-water heating system is considered 

to be more temperature-consistent. The

Fig. 14: Arrangement of double-wall piping in ventilation system 

glycol-water flow is constant and inde- 

pendent of the LNG flow rate. The va- 

poriser-gas outlet temperature (45 °C) 

is controlled by the glycol-water tem- 

perature set-point. 

Gas-pressure control: 

The cryogenic pump is equipped with a 

discharge control valve. When the dis- 

charge control valve is open, gas flows 

to the vaporiser. If the gas pressure from 

the vaporiser outlet is higher than the 

gas pressure set-point from the GECU 

(ME-GI engine control system), the 

cryogenic-pump speed is decreased. If 

the cryogenic-pump speed reaches the 

minimum speed, a control valve opens 

to the venting mast. 

Gas train 

The gas is supplied from the vaporiser 

outlet through a single-wall, high-pres- 

sure pipe to the gas train, installed out- 

side the engine room, consisting of two 

block valves and one bleed valve (see 

Fig. 13). 

The volume between the block and 

bleed valves is depressurised while the 

gas system is out of operation (block 

valves are closed and bleed valve 

open). This is a safety arrangement in 


order to ensure that no gas can unin- 

tentionally be supplied to the engine. A 

valve-leakage test is automatically con- 

ducted before gas operation based on 

the pressure-drop over time. 

Double-wall gas pipes 

From the gas train, the gas enters the 

engine room and from here the gas is 

supplied courtesy of a double-wall pip- 

ing system. These are, according to 

IMO guidelines, “gas-safe machinery 

spaces” where the engine room is main- 

tained as an ordinary engine room and 

not a hazardous area. The space be- 

tween the inner, high-pressure pipe and 

the outer pipe is continuously ventilated 

– approximately 30 air changes per 

hour – by a mechanical ventilator made 

of spark-free fan material, installed out- 

side the engine room. The double-wall 

inlet must be supplied from a gas-safe 

area. In the event of a gas leakage from 

pipe rupture or sealing failure, the leak- 

age is detected with a HC sensor in- 

stalled in the ventilation-pipe outlet. The 

double-wall piping should be arranged 

as shown in Fig. 14. 

The double wall ventilation system 

is also part of the engine internal gas 

system and every valve, gas injection 

valves and high pressure sealings are 

connected to this system. The high 

pressure outlet from the engine will have 

to be connected with a silencer of suf- 

ficient capacity – see Fig. 15. 

Fig. 15: The high-pressure engine outlet needs to be connected with a silencer of sufficient capacity 


16

N 2 purging system: 

During every gas-system depressurisa- 

tion, an inert-gas purging system must 

be connected manually or automatical- 

ly, in order to purge out remaining gas 

or oxygen. An additional valve before 

the first block valve and connected to 

the outlet silencer must also be installed 

so depressurisation and purging is pos- 

sible. 

Control and safety system: 

The ME-GI control system supplies a 

gas pressure set-point to the gas-sup- 

ply system depending on engine load, 

that is, gas-pressure dynamics follow 

engine-load dynamics. HC sensors 

must be applied to the gas-supply sys- 

tem in order to detect leakages. 

Task & 

Schedule 


Development 

Test rig 

development 

4T50ME-GI 

Research 

Engine 

Development of 

Gas Injection – 

ECS 

Helios Project 

EU FP7 

7S60ME-GI8 


Order 

6 Test Program 

MAN Diesel & Turbo has established a 

comprehensive test program stretching 

over the next three years. Fortunately, 

the rebuilding of the test engine to ME- 

GI gas operation will not restrict tests 

running on diesel fuels as the test en- 

gine can inherently change over be- 

tween the two types of fuels. Tests are 

planned to commence in March 2011. 

1. Verification of test set-up 

2. Confirmation of system for basic gas 

operation and performance tests. 

One very interesting target is to de- 

termine the lower limits for pilot-oil 

volume and the minimum engine- 

load at which the engine can operate 

in gas-burning mode. 


3. Subsequently, a series of gas param- 

eter tests are planned covering: 

emission and performance 

combustion optimisation 

verification of Tier-II setup 

parameter variation for Tier-III setup. 

Both Tier-II and Tier-III tests will be per- 

formed with EGR and/or WIF. 

The potential for CO2 and SO x emis- 

sions reduction by using LNG instead 

of HFO has garnered significant sup- 

port from the EU for the test program 

through the so-called “HELIOS” project. 

Year / Quarter 2009 2010 2011 2012 2013 

Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 

ME-GI concept 

Test rig TS50ME-GI 

Test Rig Start 

Test & Optimization 

Conversion 4T50ME-GI 

Decision full Scale Test 

Agreement DSME 

Agreement HHIEMD 

Gas Injection & Engine Control System; GI-ECS 

Preparation 

Design Order (DSO) 

Evaluation 

QG Letter of intent 

Application 

Full grant obtained 

Fig. 16: A Gant diagram showing the test program for a retrofit conversion to LNG- 

Cont. 

Tier II Test Cont. Tier III Test 

Engine Start Tier II verifikation 

Customer Demonstration 

Start integration test 4T50ME-GI 

First Order ME-GI 

QG Order Yes/No 

Execution 

Cont. 

Tier III 

verifikation 

ME-GI retrofit (46x 2x6/7S70ME-GI)

7 Potential Applications for ME-GI 

Engines 

As previously mentioned, the ME-GI 

engines – originally designated MC-GI 

– were developed for LNG carrier pro- 

pulsion. In the project phase, the ME-GI 

was recommended for the now-famous 

45-strong Qatargas fleet of Q-Flex and 

Q-Max LNG carriers built for the mas- 

sive expansion of gas exportation from 

Qatar in the Persian Gulf. 

However, the shipowner selected 

the heavy fuel variant and, accord- 

ingly, each of these vessels has 2 × 6 

7S70ME-C HFO engines installed. In 

the meantime, the relative pricing of gas 

and fuel has changed in some parts of 

the world and a retrofit project is now in 

the shaping, with some of these vessels 

as candidates for retrofit to 2 x 6 type 

7S70ME-GI. 

These vessels already have a relique- 

faction plant on board so therefore the 

gas-supply train to the engines features 

a cryogenic pump/evaporator. It is es- 

timated that such a retrofit installation 

would take about one year to prepare, 

followed by 4 - 6 weeks re-building, 

which typically would take place during 

a regular survey docking. Fig. 16 shows 

a Gant diagram for such a conversion. 

The ME-GI engine can also be seen as 

a way of simultaneously meeting Tier-III 

emission limits and fuel-sulphur con- 

tents/SO x emission limits. With natural 

gas being sulphur free, SO x emissions 

from an ME-GI engine are limited to that 

emitted by the burning of pilot oil. 

The extremely low SO x emissions from 

an ME-GI engine also facilitate the nec- 


essary Tier-III NO x control abatement 

methods for two-stroke engines, SCR 

( Selective Catalytic Reduction ) and 

EGR (Exhaust Gas Recirculation ). For 

SCR, the SO x in the exhaust limits the 

temperature regime in which the reac- 

tion can take place while for EGR, the 

exhaust gas to be recirculated needs to 

be cleaned and cooled before returning 

to the engine. This is obviously much 

cleaner when derived from an ME-GI 

combustion. Therefore, an ME-GI en- 

gine with SCR or EGR could constitute 

a Tier-III, low-speed engine as an alter- 

native to an ME-type HFO engine with 

SCR or EGR and SO X scrubber. 

The fact that natural gas is generally 

cheaper than HFO on a calorific input 

basis, while low-sulphur or even sul- 

phur-free fuels are significantly more ex- 

pensive than HFO, supports the use of 

ME-GI engines. 

The regulatory environment is practical- 

ly in order already and the logistics for 

running on gas will come with demand. 

Accordingly, advanced shipbuilders – 

particularly in Japan and Korea – are 

already marketing containerships, tank- 

ers and bulk carriers powered by ME- 

GI engines. Bringing development one 

step further, MAN Diesel &Turbo has 

recently also decided to advocate the 

use of LPG and other VOCs (Volatile 

Organic Compounds) in a variant of the 

ME-GI engine. This will be designated 

ME-LGI (for Liquid Gas Injection). While 

the ME-GI probably will be used mostly 

in larger vessels on longer routes, the 

ME-LGI will be used more predomi- 

nantly in short-sea shipping due to the 

easier logistics offered by LPG/VOC. 

Conclusion 

There is plenty of gas available in the 

world, with some sources evaluating its 

reserves as even greater than oil. The 

main drivers for using gas at sea are 

first and foremost environmental con- 

siderations – including a great reduction 

in CO2 emissions – but the cost of the 

various fuel types are also an important 

factor. MAN Diesel & Turbo sees great 

potential in the use of gas aboard ships 

and is allocating substantial research 

efforts towards developing suitable 

technologies to this end. 


18

19 The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s Copenhagen Test Centre



20

21 The 4T50ME-GI Test Engine at MAN Diesel & Turbo’s Copenhagen Test Centre

MAN Diesel & Turbo 

Teglholmsgade 41 

2450 Copenhagen SV, Denmark 

Phone +45 33 85 11 00 

Fax +45 33 85 10 30 

info-cph@mandieselturbo.com 

www.mandieselturbo.com 

Copyright © MAN Diesel & Turbo · Subject to modification in the interest of technical progress. 

5510-0107-00ppr Feb 2011 Printed in Denmark

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