海洋能源系统的集成建模框架的设计、操控和控制

Rapidly varying fuel costs, environmental
concerns and forthcoming emissions regulations
impose a pressure on ships to operate in a more
efficient, cost-effective and environmentally friendly
way. The propulsion power and energy producing onboard
installation– i.e. the marine energy system – is
the main contributor to the overall cost-effectiveness,
emissions footprint and efficiency of the vessel. To
meet those stringent and often contradicting requirements,
the sophistication and, hence, complexity of
modern marine energy systems increases, while operating
frequently at extreme conditions and close to
the design limit. The challenge of making both existing
and new marine energy systems more energy
efficient and environmentally friendly imposes a need
for new approaches for system configuration, design,
operation and control that are able to consider the energy
production and conversion onboard ships (fuel,
mechanical, electrical, thermal) in an integrated manner.
At the same time, simultaneous assessment of
performance, safety, and reliability of marine systems,
especially under real service conditions and transient
operation modes are becoming increasingly important
for both ship-owners and classification societies.
To date, however, there is no formal methodological
framework to cover the aforementioned needs in
a holistic way. In this paper we present a novel approach
for integrated dynamic process modelling and
simulation of marine energy systems. Our methodology
is based on the mathematical modelling of the
dynamic thermofluid behaviour of components including
energy conversion and rotating machinery such
as heat exchangers, evaporators, compressors, turbochargers,
pumps, valves, pipes, etc. The component
process models are generic, reconfigurable, suitable
for different types of studies and valid for a wide
range of operating conditions. Then, following a hierarchical
decomposition approach the lower-level component
models are used to synthesise higher level subsystems
and, in turn, complete energy systems. Experimental
or service data are used for model verification
and validation. The models are implemented
in state of the art process modelling tools, where they
are coupled with representations of operational scenarios/
profiles. In that manner we are able to perform
a variety of model-based studies and applications like
steady-state and dynamic simulation, design, optimisation
and control of user-defined energy system configurations
under realistic service conditions.
The developed modelling framework aims at providing
model-based decision support on: a) energy
and emissions optimal design of onboard machinery,
b) performance evaluation under real-service dynamic
conditions for the whole mission envelope of
the system, and c) assessment of the potential and
operational capabilities of innovative designs. The
main benefit from this holistic approach is that the
steady-state design characteristics, off-design operational
modes and dynamic/transient behaviour can be
simultaneously assessed and/or optimised in a unified
and consistent modelling framework. The presented
approach can significantly aid the design process for
new systems as well as the energy management, performance
prognosis, and control optimisation and reconfiguration
for existing vessels. The main characteristics
and benefits of our methodology are illustrated
via the dynamic modelling of a marine combined cycle
system.