CIMAC Congress - Schiff & Hafen

Monday, 14 June
Wednesday, 16 June
Thursday, 17 June
Tuesday, 15 June
started to develop a lean burn dual fuel engine (DF). Today Wärtsilä
has a product range for the DF engines ranging from 800kW to
17,550kW. The dual fuel engine has the ability of combining the
benefits from operation on both diesel and gas. In diesel mode, the
engine is able to operate with a high efficiency and at the same time
meet the demands regarding NOx emissions and variation in load.
In addition to this, the engine can be operated on both marine diesel
oil as well as heavy fuel oil. In gas mode the engine has an even
higher efficiency and the NOx emissions are already at such a level
that it will meet the coming demands for the marine industry. In
order to meet the demands from the market, Wärtsilä is continuously
developing the dual fuel engines regarding ability to operate in gas
mode at the highest performance when the gas quality is changing.
The dual fuel engine must be able to work with the highest
performance though the fuel quality is changing. The paper will
show how the engine can adapt to the fuel and thus be operated with
a high performance. The demand for mechanical drive for the dual
fuel engines is also growing in order to have an easy installation
combined with a wide operation range regardless of the fuel. The
mechanical drive for Wärtsilä 34DF and Wärtsilä 50DF is being
developed and the paper will show features that are crucial for a dual
fuel engine operating on a variable speed with a high demand on
loading capabilities. Test results from operation on variable speed as
well as load acceptance performance will be shown.
Experiences on 1 to 6 MW class highly
adaptable micro-pilot gas engines in one
hundred fields and over fifty thousand
running hours
S. Nakayama, S. Goto, T. Hashimoto, S. Takahashi,
Niigata Power Systems Co., Ltd., Japan
Niigata has a success story about original micro-pilot gas engines that
are high-density gas engines with BMEP of 1.96MPa. Niigata 22AG
series have been applied as the key hardware in cogeneration systems
in Japan since 2002. The total delivered number is over 100 units, and
generating power is over 200MW. The 22AG series consist on in-line
type 6, 8, V-type 12, 16, 18 cylinders, which cover from 1MW to 3MW.
Most of all engines have been in operation approximately 8000 hours
at BMEP 1.96 MPa continuously in a year. The first delivered three
8L22AG engines have since been operated continuously every day,
which the running hour per year corresponds to 8000 hours. There
were no serious problems until now, July 2009. The total operation
time is 55,000 hours and minimum engine stop maintenance interval
is 4,000 hours as scheduled. The engineering findings that the
performance of various field applications and their operation history,
durability of engine parts are described in this paper. Field results for
one-year experience of our 6 MW class 28AG type gas engines, which
were delivered in 2008, are also described. In Japan, specific operation
and special adjustment for individual cogeneration system is required
according to the unique power supply circumstances. Niigata
cogeneration system based on AG series gas engine has been
progressing to have robustness in order to meet these individual
requirements. Some specific examples are introduced here. In some
region, commercial electric power failure occurs by thunder sometimes
and it is a big risk for customers production. When service electricity
happens to stop suddenly, normally engine-generating system is
stopped according to the reason of grid system. AG cogeneration
system can survive for such case with still keeping power generating.
This robust operation can provide the safety plant running, for
example for chemical plant being desired to keep the reaction
temperature constant. Figure 1 shows the time chart of the sudden
load decrease from full load to 55% load. Some factories in Japan are
located in the area like mountainous region where fuel gas pipeline
networks do not spread enough and in such case LNG satellite supply
fuel is used. Property of fuel gas evaporated from LNG is not always
constant so the heating value varies with time. The property variation
causes knocking phenomena. Highly reliable knocking control system
with fast response is essential. Many gas engine generation systems do
not only use the power generated by own gas engine systems but
some quantity of commercial electricity. One of the customers needs
is to keep the amount of commercial electricity consumption constant
to low level. In some plant, the frequency of engine start/stop has to
increase to cope with the power demand. The frequent start/stop is
not good for the engine parts. Niigata patent; spark start micro-pilot
system is clear function to secure frequent start/stop operation and
quick power generation.
Exploration of optimum design parameters
for Miller-Cycle lean-burn gas engines
D. Montgomery, S. Fiveland, S. Vijayaraghavan, H.
Sivadas, M. Willi, Caterpillar Inc., USA
Gas engines for stationary applications are rapidly expanding in
popularity. In order to continue this trend, widespread attention is
being paid to extend operating modes to enable higher efficiency
whilst maintaining detonation margins. A strong enabler of high
efficiency in lean burn gas engines is Miller cycle. The limits of Miller
cycle operation are often imposed by production hardware limitations
and valve-train dynamics. A study was undertaken to explore the
fundamental limitations of Miller cycle operation. This paper explores
the boundaries of Miller cycle performance augmentation in gas
engines. Fundamentally, Miller cycle is used to transfer work from the
compression stroke of the piston to the turbocharger. This transfer
reduces pumping losses during the compression stroke and takes
advantage of exhaust enthalpy that is otherwise wasted. As more
compression work is transferred, the potential for higher engine
efficiency increases. Unfortunately, the exhaust stroke pumping losses
increase with increasing Miller effect. Thus, an optimum exists where
the exhaust pumping losses start to outweigh the gains extracted by
decreasing the work done during the compression stroke. Using a
proprietary Gas Engine Cycle Simulation code, the limitations of
production engines were removed to explore the future feasibility of
aggressive Miller cycle in lean burn natural gas engines. An optimum
balance was found after manipulating turbocharger configurations,
compression ratio and valve events.
8:30 June 15th Room Klokkeklang
(9–1) Turbochargers & Turbomachinery –
New Products
New turbochargers for more powerful
engines running under stricter emissions
regimes
P. Neuenschwander, M. Thiele, M. Seiler, ABB Turbo
Systems Ltd., Switzerland
The latest and coming rounds of emissions legislation for reciprocating
engines in marine, stationary and mobile applications require much
cleaner exhaust gas emissions. At the same time, demand for higher
engine power density and reduced life cycle costs is steadily increasing,
with the latter and the volatile price of fuel translating into the
underlying requirement that improvements be achieved at unchanged
or reduced specific fuel consumption. The possible technical solutions
for meeting the targets described depend on the field of application of
the engines. These differ widely and, with its role as a central influence
on the combustion process, decisively affect the demands made on -
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