CIMAC Congress - Schiff & Hafen

CIMAC CONGRESS | BERGEN 2010
measurements, used as reference, findings regarding the flow scheme
in cylinder oil supply lines will be discussed. This comprises two
types of common electronically controlled injector systems.
Measurements did reveal a surprisingly high flow dynamic in the
low pressure feed lines which require further corrective actions to
ensure precise results. The paper includes measurement results as
well as a discussion of the options to further reduce cylinder oil
consumption. The latter are based on the availability of real time
consumption measurement results which can be used for the
calibration of electronically controlled injector systems.
Combustion quality of marine residual fuel
– trend, control, effect on engine
A. Takeda, N. Iijima, S. Umemoto, H. Miyano, Nippon
Yuka Kogyo, Japan,
H. Nakatani, K. Adachi, H. Nomura, K. Adachi, NYK
Line, Japan,
H. Tajima, Kyushu University, Japan
The effectuation of the IMO/MARPOL 73/78 Annex VI and the
requirement for reducing the sulfur content in accordance with
future regulations have strongly influenced the qualities of marine
residual fuels. For example, since light cycle oil (LCO) and clarified
light cycle oil (CLO), which are obtained in the fluid catalytic
cracking (FCC) process, contain a low level of sulfur and low
viscosity, they are suitable for use as raw material for low sulfur fuels
such as cutter stocks. However, a major portion of these types of oil
generally contain aromatic compounds, and in the case they are
blended in large quantities to marine residual fuel, its ignition and
combustion quality deteriorate. As a result, lowered combustibility
causes problems such as poor combustion in large two-stroke diesel
engines (main propulsion engines), which can potentially result in
major failures such as damage to the piston rings and the cylinder
liner. However, there is no limit value or criterion regarding ignition
and/or combustion quality of marine residual fuel at the current
moment. Therefore, fuel oil suppliers do not need to pay attention
about ignition and/or combustion in the petroleum refinery process
with which marine residual fuel MFO is made. Energy Institute (EI)
had standardized the test method (IP541) of ignition and
combustion characteristics for residual fuel by using constant
volume combustion chamber such as Fuel Combustion Analyzer
(FCA) in 2006. However, a practical evaluation method and the
criterions for the ignition and combustion quality are currently
under consideration in CIMAC and ISO, and are therefore not yet
established. And, there are few reports on the ignition and
combustion quality of a large number of marine residual fuels by
IP541. Since combustion problems are increasing in recent years,
the consumer takes the necessary measures to minimize engine
problems caused by poor combustion quality. In this paper, we will
report the results of investigation and research for ignition and
combustion quality, and the experiences obtained from operations
of engine.
The users views of having to use lowsulphur
fuels combined with slowsteaming
K. Wilson, Keith Wilson and Associates, England
The present world wide economic situation has meant that almost
all ship operators have to employ slow steaming with their ships.
Long hours, or days, with engine operation at loads of 30 per cent,
or even less, bring problems with those engines and these are not
easy to solve, including ensuring that the exhaust gas meets with
local requirements, where necessary. At the same time, the increasing
number of sea areas (SECA’s) which demand the use of low sulphur
content fuels or, very low sulphur exhaust gas emissions, from all
ships, present more problems for the engine operator – the User.
The paper sets out to show the depth of these problems and in
particular the effects on engine operation, and how the Users are
dealing with them. Since the use of low sulphur content fuel oils is
now mandatory in different areas, the USER has to invest in extra
equipment to deal with such fuel oils at the same time as extra
investment in sometimes complex adaptations of the engines, have
to be made. In addition, there now seems to be a problem of how
much low sulphur content fuel can be supplied in some ports,
particularly where large ships are concerned. Furthermore, new
regulations have been brought forward rapidly, where exhaust gas
emissions are concerned, in waters off the state of California, USA.
These go well beyond the present requirements laid down by the
IMO to which all Users have taken considerable steps, in conjunction
with the engine designers, to meet the present IMO tier requirements
and the next IMO tier. The latest requirements as laid down for
Californian waters, mean that each User has to invest in further
equipment on board when it will only be used for a relatively short
time in each voyage. The need for unilateral exhaust gas emissions
across the world is paramount to the Users but there are now several
authorities who demand their own exhaust gas emission levels.
Apart from the larger main engines on board many of the Users’
ships, the change over from heavy marine fuel to a much lighter
grade of fuel oil can cause problems with auxiliary engines designed
to use only one fuel oil type. For those Users operating machinery in
tankers, the problem is further aggravated by having to deal with the
exhaust gas emissions from the boilers where much use is made of
heavy fuel oil for considerable periods since fresh water generation
onboard is essential. Dealing with sulphur in the exhaust gas, on
board has yet to be fully exploited.
Environment-friendly operation using LPG
on the MAN B&W dual fuel ME-GI engine
R. S. Laursen, MAN Diesel & Turbo SE, Denmark,
V. W. Rudh, Hamworthy Gas Systems AS, Norway
With the new gas code, the use of LPG, i.e. propane and butane, as
fuel for propulsion of ships has now come one-step closer, and
MAN Diesel is ready with an engine design for this specific use. LPG
has been used as a fuel in the car industry for many years, and now,
with the dual fuel ME-GI engine, it is also possible to use LPG on
ships in general. The discussion and interest in lowering CO 2
, NOx,
SOx and particulate emissions have increased operators’ and ship
owners’ interest in investigating future fuel alternatives. Using LPG
as fuel on the two-stroke ME-GI offers the same emission benefit as
with LNG, where emissions can be reduced significantly compared
with MDO. Therefore, there are very good environmental reasons
for using this fuel in coastal areas and on inland waterways. The GI
system can also be applied on the small bore ME-B engines, which
suit into smaller tankers, bulk carriers, container vessels and RoRo
ships. Because of the general need to reduce CO 2
emissions, it is
already seen in some regions, especially in the Mediterranean, that a
lot of traffic is being moved from the highways to the seaways. This
trend is expected to continue because sea transportation has proved
to be less CO 2
polluting than both trucks and trains. This CO 2
benefit can be further improved by using gas as the fuel. Many ship
owners have realised that in the next five to six years there will most
likely be an overcapacity in the LNG carrier fleet and in the LNG
production. Obviously, this generates an interest in using LNG and
LPG as a fuel on ships in general, since the gas fuel for a period is
expected to be cheaper than other types of fuels, and the difference
will be even bigger when comparing with other types of low-sulphur
fuels. LNG is considered the fuel of the future, and very few doubt
76 Ship & Offshore | 2010 | No. 3