Saturday, 22 October 2016
Delphi unveils smaller diesel fuel injector for 2021
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.”