The container ship Arnold Maersk where the ORC
unit was installed. Foto: Colourbox.
(a) High pressure combustion vessel at Sandia
National Labs, (b) high speed measurement of
soot optical thickness and (c) simultaneous high
speed measurements of liquid and vapor phase of
fuel spray.
The test facility. Foto: Kosan Crisplant.
PilotORC – Organic Rankine cycle unit for waste heat recovery on ships
The project PilotORC was aimed at evaluating
the technical and economic feasibility of the
use of organic Rankine cycle (ORC) units to
recover low-temperature waste heat sources on
container vessels. The project included numerical
simulations and experimental tests on a 125
kW demonstration ORC unit that utilizes the
waste heat of the main engine cooling system
on board one of Maersk’s container vessels. The
project was carried out in cooperation between
DTU Mechanical Engineering and Mærsk
Maritime Technology, and it was funded by Den
Danske Maritime Fond and Mærsk Line.
Several simulation models were developed to
evaluate alternative integrations of the ORC
units with different sources and configurations.
The developed models allowed for the study
of different ORC configurations at design and
off-design conditions, the simulation of radialinflow
turbines, and the prediction of thermophysical
properties of alternative working fluids.
The models for the ORC unit were validated
using the experimental data collected during
the onboard testing. The ORC unit has been
working uninterruptedly since it was installed
in April 2016, demonstrating the matureness of
the ORC technology for maritime applications.
The validated models were used to evaluate
the retro-fitting potential of using ORC units
for maritime applications, and the relevance
of this technology for new building projects.
The estimations indicate that significant fuel
savings can be achieved. It was found that
integrating ORC units with the jacket cooling
water within the service steam circuit could enable
payback periods of approximately 5 years
and high fuel savings. Conversely, if the heat
from the exhaust gases would be recovered, the
total power production of the ORC unit could
cover 10 % of the main engine power. Larger
energy savings, 10-15 %, could be expected if
advanced design methods are employed.
Experimental study of liquid fuel combustion
This study has been part of the RADIADE
project, investigating the influence of radiative
heat transfer on heat loss in large marine
diesel engines. Advanced optical diagnostics
are applied to measure various combustion
and flow characteristics of high pressure liquid
fuel sprays. The experiments are conducted in
a constant volume combustion vessel able to
generate an ambient environment with welldefined
boundary conditions resembling the
environment encountered inside a diesel engine
cylinder during the combustion event. The
measurements are used to validate numerical
models that can be used to simulate the effect
of multiple design parameter variations on engine
performance and emissions. This work has
contributed with a new measurement technique
designed to measure light extinction at high
speed in an optically harsh environment. The
measurement technique successfully measured
the liquid spray and soot volume fraction in a
diesel type flame and has been established as a
measurement standard within the international
research collaboration “Engine Combustion Network”.
The results were published in the Journal
of Applied Optics and the paper was featured in
“Spotlight on Optics”, where select articles are
identified by the journal editor to reflect the
breadth and quality of their journal. Another
significant finding was being able to isolate the
effects of in-nozzle cavitation on the combustion
and flow characteristics of the spray flame.
Being able to measure the characteristics of
spray flames accurately is a necessity for evaluating
the thermal radiation emitted by these
types of flames. The thermal emission from the
hot gas and soot in a representative spray flame
was simulated with a 1D model showing that
thermal emission from the gas is in the same
order of magnitude as that from soot, which is
contrary to the common perception amongst
combustion scientist.
Shore based small scale LNG/LBG liquefaction unit
Liquefied natural gas (LNG) is seen as a promising
alternative fuel for ships, due to its lower
CO2 emissions and considerably lower emissions
of NOx and SOx compared to the heavy
fuel oils typically used for ship propulsion today,
and thus enabling the ships to comply with
the targeted emission reductions of the future.
Today, LNG for ship fuelling in Denmark, e.g.
the ferry operating between Samsø and Hou,
is trucked from largescale production facilities
in Rotterdam. The aim of this project was to
develop an energy efficient small scale production
facility to be placed directly in the ports.
Natural gas (NG) will be supplied directly from
the NG-network, or alternatively, biogas from
local producers could be supplied, producing
liquefied bio gas (LBG).
The project was carried out in a collaboration
between Kosan Crisplant, DTU Mechanical Engineering
and Moving Energy. Based on advanced
simulations models, used for the optimization
of the plant layout, a test facility was designed
and built by Kosan Crisplant. A mixed refrigerant
layout was chosen and the optimal refrigerant
mixture, operating temperatures and pressures
were found taking into account the composition
of the local NG. The final plant layout showed
a predicted energy consumption of 0.4 kWh/
kgLNG, which is 40 % lower than the EU target
towards these type of systems.
Measurements from the test facility were used
for validation of the simulation models. The
next step will be the establishment of a demonstration
plant in the port of Frederikshavn.
This project was carried out under the framework
of the Danish societal partnership Blue
INNOship and was partly funded by the Innovation
Fund Denmark under File No. 155-2014-10
and the Danish Maritime Fund.
Contact:
Fredrik Haglind, e-mail: frh@mek.dtu.dk
Contact:
Fredrik Ree Westlye, e-mail: frrwe@mek.dtu.dk
Anders Ivarsson, e-mail: ai@mek.dtu.dk
Contact:
Wiebke Brix Markussen, e-mail: wb@mek.dtu.dk
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