Delphi Diesel Systems has
demonstrated its next generation technology – the DFI 21 common rail injector.
Set to enter production in 2021, the new injector is
an evolution of Delphi’s current F2 injectors. It is smaller and faster.
“Central to the
DFI 21 is a further miniaturisation of the control valve, from 2mm in our Euro
VI solution to 1mm,” claims James Kewley, chief engineer – commercial vehicle fuel injection systems at
Delphi Diesel Systems based in Stonehouse, Glos., UK. The business has its roots in the former Lucas Diesel Systems of Acton, west London. Stonehouse was built to supply systems in high volume for Volkswagen.
“We
have shrunk the valve; it allows us to have smaller fuel injections closer
together, with more precision,” he adds.
An additional benefit
of shrinking the valve is a reduction in the parasitic losses and leakages
associated with each injection.
“We can operate
DFI 21 with nine injections per cycle at 3,000 bar,” further claims Kewley. “The end result is a fuel consumption improvement of around
three-quarters of a percent.”
Kewley views this is significant
for fleet operators.
“If you consider
heavy-duty vehicles, this will equate to a saving of around US$123 per annum
for each truck,”
he notes. “When you have a
fleet of hundreds of vehicles, it all adds up.”
“CO2 and fuel
efficiency will be the two prevailing trends over the next five to ten years of
technology development in CV powertrains,” says Kewley. “The reason I say that is because in Euro VI, it has been demonstrated that
NOx emissions from trucks are under control.
He believes
authorities in Europe and the US are driving the strategy on CO2 reduction
across the world, with Korea and Japan following swiftly behind.
“We’re beginning to see other countries like China and India catching up.
Interestingly, China is picking some of the best parts of the European and US
regulations, which is providing us with some significant challenges.”
Modular approach is needed
Kewley suggests Delphi
and others will need to take a modular approach with both hardware and software
powertrain technology before shaping them for markets like China.
Looking ahead, he
notes that European authorities have yet to finalise the next round of
emissions regulations for CVs.
“However, there are “strong indications that there will be a reduced NOx target, but by far
the bigger trend going on is greenhouse gas reduction with an emphasis on CO2,” he adds.
He also refers to the
adoption of portable emissions measurement systems (PEMS) as a significant
challenge for the future.
“What we see is
that there will almost certainly be further application of PEMS, and the
envelope over which demonstration of compliance in the field will broaden. For
example, cold start will be a requirement, which provides some significant
challenges in terms of efficiency,” he notes
According to Stratview
Research, the global automotive fuel injection system market will grow at a
CAGR of 6 per cent between 2016 and 2021. The study highlights a number of
other suppliers, including Denso, that are likely to take advantage of this
growth.
In 2013, the supplier
launched a diesel common rail system with 2,500 bar injection pressure,
increasing fuel efficiency by 3% while simultaneously reducing NOx by 8 per
cent and PM by 50 per cent.
In July 2016,
the company received an Environment and Safety Technologies award from the
Institute of Electrical and Electronics Engineers (IEEE) for its electronically
controlled diesel injection system.
Denso is working to further improve the efficiency of its injectors,
with a particular focus on “increasing the
fuel injection pressure and accuracy to meet the increasingly stringent
emissions regulations around the world.”
Kewley reckons the
application of next-generation, efficient and precise fuel injections could be
broad.
He thinks Delphi’s DFI 21 injector will be
particularly suited for the heavy-duty and medium-duty CV segments, though he
suggested that it could also be used in smaller trucks.
“Take some of
those light distribution applications that operate in cities, for example,” he says. “Although there is a lot of talk about electrification, I think it will
take a long time to penetrate. So there will still be a significant need for
many smaller distribution trucks to be diesel powered, and therefore these kind
of technologies will be equally important for those type of applications.”
Referring to Delphi’s work with Westport to jointly develop a new high-pressure direct
injection (HPDI 2.0) system designed specifically for natural gas (NG) trucks.
The technology uses a
small pilot injection of diesel to ignite followed by a large primary injection
of NG.
“The result is a
20% CO2 reduction versus a diesel system,” Kewley
said. “This is definitely something we believe could have a big impact on the
CV segment.”
1 comment:
The Lucas Diesel Systems business in Gloucestershire started on the Gloster Aircraft site at Hucclecote, the first production line making electronic unit injectors (EUIs) for Caterpillar in the US. The much-smaller EUIs for VW came along later.
However, EUIs (and their unit-pump derivatives) are now old hat. Every automotive diesel manufacturer of note has moved to common rail technology, though Delphi - for its two main OEMs Volvo and DAF - has done it cleverly, retaining two of the six camshaft-actuated pump elements to pressurise the rail.
A quite different type of injector is needed in a common-rail set-up and it's probably true to say that Delphi's previous VW EUI experience has been valuable, by way of component miniaturisation, for its latest downsized F2 injector.
Though Delphi hasn't said so, the HPDI natural gas injector being developed with Westport is likely to see the light of day first in a Volvo 13 litre engine.
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