CIMAC Congress - Schiff & Hafen

CIMAC CONGRESS | BERGEN 2010
Application of a SCRT system at modular
power plant based on ‘On Road’
technology
M. Himmen, I. Zirkwa, F. Kunz, HJS, Germany
J. M. Lippert, HummelEnergie Systeme, Germany
Session 5
Introduction of Doosan water in oil
monitoring system, O-WACS
K. -T. Hong, J. -S. Park, M. -C. Park, S. -J. Kim,
Doosan Engine, Korea
New Mahle innovative steel piston
designs for high performance gas
engines
T. Estrum, Mahle GmbH, Germany
Session 11
PID controller auto-tuning for ship power
plant simulation system
F.E.I. Jingzhou, Harbin Engineering University,
China
Inclusion rating of clean steels: A study
on role of steel cleanliness on fatigue
performance of forged steel components
used in marine propulsion
K.Y Sastry, J. O. Nokleby, Det Norske Veritas AS,
Norway,
M. Hekkanen, M. Jarl, Oerebro University,
Sweden
The integration of mean value first
principle diesel engine models in
dynamic waste heat and cooling load
analysis
H. Grimmelius, H. Nicolai, Delft University of
Technology, The Netherlands,
D. Stapersma, Netherlands Defence Academy,
The Netherlands
8:30 June 17th Room Peer Gynt Salen
(8–3) Integrated Systems & Electronic Control –
Engines, Turbines & Applications –
Operation & Field Experience
Scavenge performance monitoring
system for Wärtsilä two-stroke engines
S. Nanda, Wärtsilä Switzerland, Switzerland
In the last couple of decades the power output from slow speed
diesel engines has increased steadily to meet the high propulsive
power demands. The major challenge in the development process
has been to maintain an optimum trade off between specific fuel
oil consumption and nitrogen oxides emission levels to meet the
present IMO Tier I levels and future Tier II levels. One of the incylinder
measures used to control nitrogen oxides emission is
internal exhaust gas re-circulation which lowers the maximum
cycle temperature by controlling the rate of heat release. Such
advances in thermodynamics of diesel engine technology has
been possible with the use of analytical tools such as
Computational Fluid Dynamics and it is now essential to develop
monitoring techniques that will be able to predict its performance
and identify faults. The most common parameters used to
monitor the thermodynamic performance of an engine are
pressure and temperature at various points on the cycle. Cylinder
pressure monitoring when used with a light spring version gives
insight into the gas exchange process. However, this technique
can fail to indicate certain faults in the thermodynamic process as
it relies only on pressure measurement which is a function of
temperature and has its limitations when it comes to monitoring
present day diesel engines operating with lower trapped air to
fuel ratio. When operating closer to stochiometric conditions,
dissociation takes place which reduces the cycle temperature. The
strong influence of dissociation results in negligible change of
cycle temperature compared to appreciable changes in air to fuel
ratio. Therefore, significant pressure changes are not observed
when operating close to stochiometric conditions. This
highlighted the need to develop a monitoring technique that
could predict the trapped air to fuel ratio of individual cylinders.
Flame visualisation tests were made to understand the the
relationship between flame size and air fuel ratio, and it was
concluded that measurement of oxygen concentration in the gas
leaving the cylinder during the blowdown and scavenging process
could act as a good indicator of combustion quality and scavenge
performance. The measurement of oxygen concentration in
engine exhaust is widely used in the automotive industry on
spark ignition gasoline engine for fuel regulation and is commonly
known as the ‘Lambda sensor’. These sensor types are typically
only capable of measuring oxygen concentrations in a narrow
band around stochiometric conditions and are not suitable for
use on compression ignition diesel engines which operate with a
high excess air ratio. A cheap and reliable lambda sensor capable
of measuring such a wide band of oxygen concentration from
zero to ambient air was made available in the market three years
ago. The sensor is active only during the period when there is a
flow in the duct. Oxygen concentration signals are recorded in
the time or crank angle domain against the exhaust valve open/
close and stroke signal. The profile of the oxygen trace and values
measured at the point of inflexion or at the instant the flow from
the cylinder stops gives an indication of the combustion quality
and the scavenging process from individual cylinders. The
scavenge performance monitoring system has been successful in
identifying faults that was not possible with cylinder pressure
monitoring.
Goal based standards in verification of
ship machinery
E. Brodin, J. O. Nokleby, H. B. Karlsen, Det Norske
Veritas, Norway
This paper proposes to move the maritime industry towards a
function based set of regulations, rules and standards. The
intention is to take a holistic view at new designs in order to
create a safe vessel by introducing an overall set of definitions
and requirements to predefined main functions. Main functions
are those functions being of vital importance for the safety of a
82 Ship & Offshore | 2010 | No. 3