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ity, environmental concerns and stringent emissions regulations.
In this landscape, the marine powerplant complexity increases significantly
under machinery space and weight limitations, multiple
safety and operational constraints, new technologies and fuels, and
inherently higher capital costs. To address simultaneously such issues,
a techno-economic approach able to take into account the design,
operation and control of the entire integrated marine energy
system throughout its mission profile is required. In this paper, we
present the techno-economic assessment and optimisation of waste
heat recovery options for an aframax tanker, a cape-sized bulk carrier
and an 8,000-TEU container ship, via mathematical modelling
and simulation techniques. Representative models of the integrated
energy system of each vessel have been developed using a modular
library of reconfigurable component process models suitable for
design, performance and transient operation analyses. To account
for the interrelations of design, operability and transient operation
between the prime mover and heat recovery subsystems, detailed
models of a diesel engine, turbocharger, power and steam turbine,
various heat exchangers and auxiliaries were used. The component
models have been calibrated and validated using measured data.
Capital cost functions for the waste heat recovery components have
been employed along with operational cost data to evaluate and
optimise the net present value (NPV) of the energy system subject
to technical, operational, safety, space and weight constraints. This
assessment and optimisation has been performed taking into account
typical mission profiles for each of the vessels considered.
The techno-economic assessment and optimisation results indicate
that there is clear potential for the waste heat recovery systems for
the selected ships. However, the best-suited configuration and savings
potential are strongly related to the specific ship type and size.
The efficiency gains and operability of the WHR system also vary
with the powerplant load demands. This study identified the minimum
attainable load for WHR system operation for each ship. In
addition, sensitivity analyses on fuel prices and capital costs have
been performed and the range of economic viability of the WHR
has been identified. Through this model-based approach complex
integrated systems can be successfully and timely investigated providing
effective decision support to system designers, integrators
and owners / operators.
Next generation of engine control systems
Alexander Levchenko, Heinzmann, Germany
The increasingly more stringent legislation with regard to pollutant
emission presents engine manufacturers and operators with great
challenges. Irrespective of whether the required standards are met
within the engine itself and/or with different exhaust aftertreatment
concepts, we can no longer do without state-of-the-art control units
that operate discretely in the background. The number of electronically
regulated components on combustion engines will continue
to increase in the future. This in turn increases the integration effort,
while also making extensive test series necessary, increases the
likelihood of responsibility conflicts (’finger-pointing’) and lowers
the level of reliability. The use of platform solutions, however, does
help to reduce system complexity, while simultaneously spreading
the testing outlay between the OEMs own R&D and development
partners. The new Heinzmann control unit model series represents
a platform solution that enables those customers who wish to develop
their own software to relieve themselves of the need to deploy
scarce and valuable R&D resources for routine tasks, and to concentrate
on the expansion of core competencies, unique selling points
and complex control algorithms. Customers that do not have their
own software department benefit from the use of Heinzmann-developed
function libraries that have proven their value in the field. An
open software platform based on RTOS has almost no restrictions
in terms of the development tools to be used. Established development
tools are supported such as, e.g. Matlab/Simulink, CoDeSys,
and, naturally, the conventional method of programming using
Embedded C. Thanks to the modular software architecture, the integration
of customer-specific solutions and protected algorithms is
extremely easy. One of the key elements in complying with state-ofthe-art
exhaust standards in diesel engines is the CR injection technology
including the control system. More and more complex actuation
algorithms, combined with calculation-intensive methods for
the compensation of injection-system component tolerances and
long-term drift, require powerful hardware and optimised software
operating-times, that when used together enable not only emissions
to be reduced, but also compensates for the wear suffered by the
injection system components. Special attention was paid to both
the simple connection ability to the various exhaust aftertreatment
components, as well as the actuation of VVT, EGR and WG. Dualfuel
applications are also gaining more and more in significance.
To this end, the new Heinzmann control system provides a basis
both for actuation on the diesel side and a comprehensive range of
monitoring and control of exhaust gas components. Here, too, our
platform solution provides ideal integration of components with
each other while the final result achieves maximum efficiency with
regard to the diesel-to-gas conversion rates and reliable operation.
Nowadays, next to pure functionality, it is the ease of configuration
and user friendliness that are of major significance. Remote support
options and fast link-up to superordinate systems is another important
factor, which enhances the appeal of the customer end product,
while opening up brand new options for developing individual
service solutions and products.
Energy management for large-bore, medium-speed
diesel engines
Robert Kudicke, Technische Universität München, Germany
Georg Wachtmeister, Technische Universität München, Germany
Alexander Knafl, MAN Diesel & Turbo SE, Germany
Gunnar Stiesch, MAN Diesel & Turbo SE, Germany
In an environment of ever rising fuel prices and stricter emission
regulations, manufacturers of large-stroke medium-speed diesel
engines need to discover new ways to reduce the fuel oil consumption
and the overall costs of their systems. As fuel efficiency has
always been the major goal, those engines convert a big percentage
of the chemical energy into mechanical energy. Unused fuel energy
leaves the combustion chamber as waste heat and enthalpy of the
exhaust gases. This paper will focus on the engine’s heat transfer
from the combustion chamber into the surrounding parts and the
cooling system. For a better understanding of the cooling systems,
a research project with MAN Diesel & Turbo SE and the Institute
of Internal Combustion Engines at the Technische Universität
Muenchen was initiated. The overall goal is to analyse and understand
the heat transfer from its origin during the combustion via
the engine block and cooling system to the environment. With the
introduction of two-stage turbocharged engines the heat load and
the complexity of the cooling systems will increase. The knowledge
of the cooling system’s behavior is essential, to face this challenge
in the near future. An analysis of three large-bore diesel engines
with a similar cylinder geometry and shaft power showed three different
topologies of the cooling system. From this analysis the following
question was deduced: Why are different topologies used
and what are the technical advantages and drawbacks of each system?
The cooling and lubrication oil systems are crucial for a safe
operation of the engine. However, there exists a trade-off between
fuel consumption on the one hand and safety on the other hand.
Smaller coolant and oil flow rates require less pumping power but
at the same time the maximum heat load of the cooling system
is reduced. A deeper knowledge about the system’s behaviour will
May 2013 | Schiff&Hafen | Ship&Offshore SPECIAL 65