Page 43 - European Energy Innovation - Spring 2015 publication

Spring 2015 European Energy Innovation 43
might impact on this strategy.
In addition, the impact of
regulation is considered. The
service aims to deliver a specific a ship depends on the speed to
set of criteria against which a
design can be based.
• “Concept Design” design
stage services are aimed at
clients who are looking to
evaluate options for optimising
future newbuilds. Factors
for consideration include
regulatory drivers such as
optimising for EEDI, ensuring
compliance against NOx
engine limits and SOx ECA
limits.
• “EEDO” services support the
client throughout the advanced
design and build stages.
LR provides independent
verification of efficiency aspects Many shipowners have worked
of the design options through
use of CFD (Computational
Fluid Dynamics) and model
test/trials witnessing.
• “EEOO” services apply to ships
in-service and focus on the
operational aspects of efficiency. assists shipowners with this using
LR has developed a series of
scalable services designed to
support ‘beyond compliance’
aspects of Ship Energy
Efficiency Management Plans
(SEEMP) through identification
of energy efficiency measures,
measurement of efficiency
and training covering the
human element part of
energy management. In
addition, Lloyd’s Register
offers assessment of various
retrofit options for ‘bolt-on’
technologies selected by the
client.
However let us look a bit closer at
the different and more practical
approaches to promote energy
efficiency.
The more straightforward way to
www.europeanenergyinnovation.eu
SHIPPING
reduce the energy consumption Dynamics), which Lloyd’s Register
is to reduce the speed. Since the has more than 20 years of
necessary propulsion power for experience in.
the power of three (and in some The result of these calculations
cases even more) there will be are summarised in an easy to read
more to save when sailing with overview which can be put on the
the “right” speed. Of course bridge so the crew can always
there is also a lower limit to how refer to it for the most optimal
slow a vessel is able to operate trim in any given situation.
both in terms of machinery and
manoeuvring and it would also Nowadays the shipyards are
be necessary to fit it into the also more willing to listen to the
ship’s schedule. In order to obtain demands and requirements of the
the same capacity it could be shipowners and this gives a better
necessary to increase the fleet, so basis for a more energy efficient
all in all it is a balance between ship. The technique behind CFD
speed, transport time, and can also be used to optimise the
number of ships. shape of the hull. It is possible to
work with a number of alternative
However there are other means designs which can relatively easy
of increasing efficiency. One way be adjusted and changed.
is to optimise the ships’ trims.
Another important factor is that
closely with trim optimisation earlier on the industry used to
because there is no need for optimise the ship in one single
any investments in the ship, design point i.e. at a given draft
since this is a purely operational and speed often called the “design
“exercise”. Most optimal trim is point”. In recent years it has
depending partly on speed and become more common to look at
partly on draft. Lloyd’s Register optimising in a wider perspective
and today the entire operations
advanced computer models profile of the ship is considered.
where the hull of a ship is defined Hereby you can cut down on
and a number of calculations are efficiency in one point, but on the
made in various combinations other hand get a better energy
of speed, draft and trim to find efficiency, also at lower speeds
the most optimal situation. The and for instance with partial cargo,
calculations are done by using so that the shipowner gets a better
CFD (Computational Fluid return of investment.
Below is an example of a trim optimisation overview where the
green fields indicate the most favourable combinations of trim and
draft in the given speed interval.