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Monday, May 13th
Tuesday, May 14th
Wednesday, May 15th
Thursday, May 16th
be kept at a low level despite the increased combustion requirements.
To control the common rail injection system, new engine
electronics were required. For the build sample 04 of the engine
series 1163, the ADEC system used on MTU Series 4000 engines
was developed further. All military requirements regarding EMC
(electro-magnetic compatibility) are being complied with. Given
the use of new technologies, the efficiency of the sequential turbocharging
system was increased significantly. The Miller cycle
results in an increase in charge-air pressure. The new build sample
was developed in a SE process using the latest methods of
design, calculation and testing. For the twelve-cylinder, 16-cylinder
and 20-cylinder engines of the build sample 04, the following
characteristics/improvements were achieved compared with
build sample 03: Emissions: Compliance with IMO II (NOx) and
reduction of PM; Charge-air pressure (abs.): Increase from 4.6 to
5.7 bar; Total ETC efficiency: Increase by 8%; Fuel consumption:
Reduction by 10% in performance map. This paper describes the
key development steps.
Tuesday May 14th / 15:30 – 17:00
Product Development
Gas and Dual-Fuel Engines – Mixture Formation
Room B
Optimisation of mixture formation in medium-speed
dual-fuel and gas engines with support of advanced
optimisation techniques and optical measurements
Ulf Waldenmaier, MAN Diesel & Turbo SE, Germany
Stefan Djuranec, MAN Diesel & Turbo SE, Augsburg
Gunnar Stiesch, MAN Diesel & Turbo SE, Germany
Fridolin Unfug, KIT, Germany
Uwe Wagner, KIT, Germany
For future gas and dual-fuel engines mixture formation is one of
the most important development areas to fulfil upcoming emission
legislations and to improve combustion efficiency. Therefore
MAN Diesel & Turbo SE is optimising the mixture formation of gas
and dual-fuel engines with support of advanced CFD-optimisation
techniques and single-cylinder engine measurements. Today’s
CFD optimisation of an intake port with gas admission pipe is an
iterative process starting with an educated first guess design, which
has to be evaluated with simulation results and engine measurements.
This evaluation is base of the first optimisation loop. The
experience of the CFD engineer is the optimisation tool in that
process. In general four to five iterations are necessary to improve
the mixture formation and flow behavior in the intake port. With
this state-of-the-art method, it takes about two weeks to reach the
design target for mixture formation. With advanced CFD simulation
and optimisation tools it is possible to get the best possible
design under consideration of the available design parameters
within days. Nevertheless, the quality of the CFD optimisation
is directly linked to the quality of CFD simulation methods. The
easiest way to validate mixture formation simulation results is an
indirect validation with engine measurements. The validation is
a comparison of the simulated mixture formation quality at the
start of ignition with engine measurements considering emissions,
knocking behavior and gas consumption. For bigger variations,
this validation shows a surprisingly good agreement. Still, investigating
flow details and a direct validation of the mixture formation
is not possible. Up to now, no optical investigations considering
mixture formation in the intake port for large engines are known.
To close this gap, MAN Diesel & Turbo SE in cooperation with
the Institut für Kolbenmaschinen of the Karlsruhe Institute of
Technology have done PIV and Mie-scattering measurements on a
modified flow bench for gas and dual-fuel engines. The measurements
aimed at flow behavior and mixture formation for different
gas admission pipes and intake valve seat rings for varying the flow
behavior in the combustion chamber. The optical measurements
helped to raise the quality of CFD-simulation methods and to improve
the mixture formation of gas and dual-fuel engines to fulfil
future emission legislation limits.
Functional improvement of a gas metering valve
Jorg Hess, Heinzmann GmbH Co KG, Germany
More stringent legislations regarding the emission of pollutants
are a big challenge for engine manufacturers, suppliers and operators.
As a result of those strict targets for CO 2
reduction, the use
of alternative fuels is moving forward. An interesting alternative
to diesel engines is presented by gas-powered engines, where it
is possible to reduce emission of pollutants significantly. Typical
gaseous fuels for gas engines include natural gas, biogas, propane
and butane, differing mainly in the calorific value, density and
stoichiometric ratio. As a consequence of the different gas properties,
depending on which gas is used in a particular engine type,
the gas flow rates can differ immensely for the same engine power
output and, conversely, different dimensions of the gas train have
to be designed and installed for the same engine type. In the power
range of 0.5 MW up to 4 MW, for high-speed engines (1500 rpm)
typically a gas dosing unit is applied, which actuates a throttle
valve to control the gas flow. The limited control of small gas flow
rate due to the nonlinear behavior of the throttle valve leads to different
valve sizes for the different gas types on one engine type and
to increasing costs of stock holding and production. Due to these
facts, Heinzmann decided to begin the development of a new generation
of gas flow control valves. An essential target of this development
was a wider variety of the turndown ratios compared with
the existing systems in the market. Furthermore, special attention
was paid to the production costs. Both requirements could have
been met with the use of special geometries and the implementation
of existing control devices. In this presentation the stages of
development, design and bench testing are presented.
The power and efficiency upgrade approach for the
development of the new Caterpillar 10 MW mediumspeed
gas engine
Volker Salzinger, Caterpillar Motoren GmbH & Co KG, Germany
Hendrik Herold, Caterpillar Motoren GmbH & Co KG, Germany
Werner Rebelein, Caterpillar Motoren GmbH & Co KG, Germany
Ioannis Vlaskos, Ricardo Deutschland GmbH, Germany
Increasingly stringent exhaust emission legislation combined with
economic pressure to realise the best achievable fuel efficiency,
which recently also is expressed as CO 2
emission, make natural gas
a promising alternative fuel for power generation plants and marine
propulsion. This is due to the combined effect of high knock
resistance of lean natural gas fuel/air mixtures, which enables high
efficiency combustion systems and the lower carbon content in the
molecules of natural gas, which reduces CO 2
emission relative to
liquid fuels. Setting the target for a new or updated product was
driven by market requirements and availability of new technologies.
The targets had to be validated by high level considerations
in order to generate a robust project plan and achieve the best
possible matching between objectives, resources and timing. As a
result, a preliminary selection of individual solutions is generated,
which is expected to enable the realisation of the specification.
In order to assess the consequences of each and every decision
made right through to the final product, a perfect balance between
May 2013 | Schiff&Hafen | Ship&Offshore SPECIAL 39