WCX17: Delphi aims for 42% efficiency with next-gen GDCI

  • 05-Apr-2017 01:53 EDT
Marc Sellnau Delphi 3Apr17.JPG

Delphi's Mark Sellnau said a GDCI engine is projected to have 22% better thermal efficiency than a conventional spark-ignited direct-injection gasoline engine and 11% better than a 2L diesel (image: Lindsay Brooke)


Delphi projects that engines employing its coming third-generation gasoline direct-injection compression-ignition (GDCI) combustion system will attain a thermal efficiency of 42%, the company said at the 2017 SAE High-Efficiency IC Engines Symposium in Detroit. That thermal efficiency would top any current production-vehicle gasoline engine, the most efficient of which are claimed to have peak thermal efficiency of about 40%.

Mark Sellnau, engineering manager, Delphi Advanced Powertrain, said a gasoline engine using the third-generation GDCI system now under development is projected to have approximately 22% better thermal efficiency than a current conventional spark-ignited gasoline engine with direct fuel injection and 11% better than a 2L diesel engine. He said many of the initial engineering challenges for GDCI have been overcome and that the company believes it can make the low-temperature combustion system emissions-compliant at the EPA Tier 3, bin 30 level.

Major advances over Delphi’s second-generation GDCI system include “wetless” combustion, quicker cold-start operation and an optimized low-temperature exhaust aftertreatment that achieves roughly 90% carbon monoxide conversion in about 4s.

Sellnau said the third-generation system has increased the compression ratio to 16:1 (from 15:1) and its new longer stroke and increased top-dead-center piston clearance enable the wetless operation that sees fuel completely vaporized before it contacts cylinder or combustion-chamber surfaces. Advanced fuel injectors operate at 350 bar (5076 psi) and provide three injection events. The third injection, Sellnau said, is “what differentiates (GDCI) from HCCI (homogenous-charge compression ignition).”

Much of Delphi’s GDCI research is being conducted under the auspices of a four-year, $9.8-million program funded by the U.S. Department of Energy; Delphi’s partners in the project include Oak Ridge National Laboratory, Umicore and the University of Wisconsin-Madison.

The system will require a variety of emissions-reduction measures that, in addition to the newly-formulated low-temperature catalyst, include an intake-air heater, gasoline particulate filter and urea injection. But Sellnau was confident those measures, coupled with the combustion-related design advances of the third-generation system, will enable a production engine to be Tier 3, bin 30 compliant—a vital achievement to advance the system for production-vehicle readiness.

Moreover, he promised the latest GDCI will operate with gasoline at currently-available octane. “We really need to get to market with commercial gasoline,” he said.

Sellanu said the project team began gathering test results for the third-generation GDCI system in February 2017 and added, “I think we’re going to see a very efficient engine evolving and going into our vehicle program.” He did not, however, provide a projection on when the system might be fitted to a production-vehicle engine.


Author:
Sector:
Mentions:
Share
HTML for Linking to Page
Page URL
Grade
Rate It
4.83 Avg. Rating

Read More Articles On

2016-08-19
Cadillac and Mercedes-Benz show slinky new concept cars that suggest autonomous driving shouldn't be inevitable.
2016-08-18
FiatChrysler's 2017 model year brings bawdy new Dodge throwback models, more Jeep variants and fewer Fiats.
2016-08-17
Predicting more accurately what happens in the complex chemical reactions between air and fuel when they are compressed and ignited in an IC engine’s combustion chamber—and solving the challenge of exhaust particulates—may have taken a step forward with the creation of the Computational Chemistry Consortium (C3), driven by the auto industry’s need to meet increasingly stringent global emissions regulations.
2016-11-15
Freudenberg Sealing Technologies has expanded its LESS (Low Emission Sealing Solution) lineup to include new products designed to address challenges associated with powertrain friction, smaller spaces, lighter weight vehicles and growth in the electric mobility vehicle arena.

Related Items

Training / Education
2010-03-15
Article
2016-11-15