Truck & Off-Highway Engineering - February 2023 - 5

TECHNICAL INNOVATIONS
cooling channels in the engine block
and the rigidity of the engine block and
the new cylinder head. There are differences
in the oil system, small differences,
but it makes a huge difference
when talking about longevity. "
To reduce fuel consumption, Scania has
pursued traditional practice in reducing
internal friction, while improved cooling
has allowed the compression ratio to be
increased. Engine calibration also has
played a part. " I would say it's a quite big
combination of hardware development
and design, together with calibration and
know-how about the industries where we
operate, " Nilsson said.
Balancing fuel consumption
and transient response
One reason why Scania quotes a fuelconsumption
reduction of 8% for the
road-going engines and 7% for the
Power Solutions variants is because of
the applications for the engines. While
road-going versions are offering around
50% thermal efficiency, there are other
factors to consider for the Power
Solutions engines, according to Nilsson.
" Our customers have in some respects
other requirements as well, which is
transient response in excavator operation
and power generation and it's a balance
between the two, " he explained.
Developers focused on optimizing control of the variable geometry turbocharger to achieve
high efficiency while satisfying customer and application demand for good transient response.
" So, I would say that the guideline was
not the overall efficiency of the engine
as such, but to make the engine based
on the truck engine and make it tailored
to the applications that we're supplying.
By that we are decreasing the fuel consumption,
depending on operation by
some five to seven percent. "
The need for good transient response
means that Scania has paid attention to
turbocharger control, too. " When we
work with industrial applications where
we had a high customer or application
demand on transient response, then we
put a lot of effort into optimizing how
we control our variable geometry turbo
to make sure that we get as high an efficiency
as possible, " Nilsson said. " Then,
not only measuring efficiency, but measuring
the transient response and how
the engine will behave in a certain operational
cycle where you have a lot of
transients. To just say that we increased
turbocharger efficiency alone is maybe
not enough. It's really related to the application
- where you install the engine
and how we can control the VGT in that
application specifically. "
These engines are likely to be operating
in harsh environments and in a
wide range of ambient temperatures.
This has meant that Scania has focused
on cold-starting ability for some time
with the current engine platform. " Now
we've made a big leap forward, "
Nilsson said, explaining two reasons
Scania engineers
worked to gather the
service points on one
side of the new engine
to make servicing it an
easier task.
TRUCK & OFF-HIGHWAY ENGINEERING
for the improvement.
" One is an electrical feed pump. Cold
diesel is very slow-moving, so that is
one thing, we can push the fuel through
the system, " he said. " And [the second
is] the sensor measuring where the engine
is rotating, [determining] when we
should inject the fuel. That improves
capability at lower engine speeds.
We're able to sense the position of the
February 2023 5
BOTH IMAGES: SCANIA

Truck & Off-Highway Engineering - February 2023

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