Delphi Automotive presented new developments in fuel injection and engine control systems that reduce carbon dioxide and nitrogen oxide emissions, helping automakers meet demanding new regulations during the Oct. 4-6 Aachen Colloquium in Aachen, Germany.
The company also showed how developing cost-effective system architecture translates into cutting edge products for all powertrain alternatives, whether gasoline, diesel or hybrid.
Some of the new developments are already being used in state-of-the-art powertrains, such as in the 2010 World Car of the Year, the Volkswagen Polo BlueMotion.
“The future of powertrain technology remains the subject of lively debate,” said Mary Gustanski, director of Engineering, Customer Satisfaction, Program Management and Operations for Delphi Powertrain Systems. “We can see some convergence in diesel and gasoline strategies as both now use direct injection, turbocharging, downsizing and even 3-cylinder engines.
“Heavily boosted, downsized engines provide high power density with low CO2 emissions, but the higher combustion temperatures and pressures involved make the reduction of NOx emissions more challenging. Delphi’s mission is to deliver undiminished vehicle performance while satisfying fuel economy needs and emissions regulations.”
Delphi diesel technology helps achieve low CO2 emissions
Delphi’s Multec common rail system, which is a robust, cost-effective modular diesel fuel injection system, helped the Volkswagen Polo BlueMotion achieve emissions of 87g/km CO2. The world’s most economical five-seater car, the 1.2L 3-cylinder diesel Polo is capable of fuel economy of 3,3L/100km (71mpg). Delphi helped achieve this exceptional performance by applying the latest evolution of its common rail system, which includes the state-of-the-art solenoid type diesel common rail injector technology DFI1.5 and the next generation DFP6 fuel pump.The technology uses balanced-valve fast servo-solenoid injectors that offer equivalent performance to servo-piezo systems but at a greatly reduced cost. The combination of DFI1.5 injectors and the DFP6 common rail pump provides improved fuel delivery control, extended multiple injection capability, enhanced spray atomization and superior air mixing. Up to six injections per cycle are possible, providing a smoother combustion event with exceptional refinement.
Vehicle stop-start functionality is supported by the DFI1.5’s ability to restart injection from rail pressures below 100bar, generating faster restart without the need to hold high rail pressure when at a standstill. Development is underway to make 80bar minimum pressure operation possible.
“The Multec system, with its unique, battery voltage driven, fast servo-solenoid injectors, enables a low-cost, structured approach at system level to support EU6 and beyond,” explained Dr. Hans-Josef Schiffgens, technical director of Delphi Diesel Systems. “The DFP6 pump sets new standards for mechanical and volumetric efficiency while eliminating any chance of high pressure leakage, offering development extension to robust operation above 2,000bar.”
Delphi’s Multec common rail latest evolutions’ improve robustness to world market fuel quality and compatibility to alternative fuels. In addition to the Multec diesel common rail, Delphi offers a direct acting piezoelectric injector common rail system for larger and higher performance engines.
Delphi’s unique Direct Acting Diesel Common Rail System has proven its ability to help high performance four-cylinder engines offer the power of a larger six-cylinder engine with excellent refinement and substantially improved emissions and fuel economy.
Indeed, the innovative award-winning injector, whereby the piezo actuator directly drives the needle position, delivers unprecedented control of the rate and shape of injection events, independent of rail pressure. This allows substantially reduced smoke emissions and therefore the use of increased EGR for affordable NOx reduction, while the elimination of fuel backflow allows significant system simplification and reduction in CO2.
Delphi GDI systems reduce gasoline engine CO2 emissions by up to 22 percent
In a technical paper entitled “Three-Cylinder Turbocharged Gasoline Direct Injection: A High Value Solution for Low CO2 and NOx Emissions,” Delphi recently illustrated the impressive CO2 reductions possible with directly injected gasoline engines, using a three-cylinder turbocharged unit. Compared to the baseline four-cylinder port-injected engine, the analysis showed that homogeneous direct injection (DI) operation reduced CO2 output by 15 to 18 percent while stratified operation achieved up to 22 percent saving.
GDI improves downsized turbocharged engines because it cools the charge, allowing higher boost levels without reducing the compression ratio, essential for efficient part-load running.
Delphi offers a family of GDI injectors that support the evolution from homogeneous to spray-stratified operation without requiring modification of the engine controller architecture. They use the same approach as Delphi’s cost-effective diesel common rail technology by employing solenoid instead of servo piezo technology.
In addition to showcasing its homogeneous injector, Delphi also focused on its spray-stratified GDi injector Multec 20. Both injectors use a patented design to give extremely low noise with precise fuel control by eliminating pintle bounce. The injectors have a broad dynamic range and are compatible with all widely-available biofuel blends.
“Delphi’s systems have the flexibility to accommodate different customer requirements for fuel flow, spray pattern, injector length, electrical connections, and other essential parameters,” said Jim Zizelman, engineering director, Gasoline Engine Management Systems and Powertrain Products. “We provide that flexibility by application engineering delivered through our global network of technical and manufacturing resources.”
In addition to injectors, Delphi’s product portfolio also includes high-pressure fuel pumps, fuel rails, electronic control modules, multi-spark ignition systems and wide-range oxygen sensors.
Delphi supervisory controller ideal for hybrids
Delphi has developed a supervisory controller that coordinates the individual propulsion sources and energy storage devices in a hybrid electric vehicle. Such vehicles rely on complex high-speed interactions between different sub-systems in order to make best use of the energy available and minimize CO2 emissions.
The controller makes decisions based on input from the driver, such as throttle or brake demand, and communicates with the engine and transmission electronics, electric motor or motor/generator and energy storage devices. It provides a gateway, for example between a CAN bus and Flexray bus and can also support safety monitoring. A total of four CAN bus interfaces; one Flexray and two LIN are provided.
The software architecture is based on Autosar standards for communication between software and hardware modules to enable software module development by the OEM or a third party.
Suitable for micro, mild or medium hybrids, full and plug-in hybrids, the controller can be mounted within the cabin or in the engine compartment and is scheduled for production in 2012.
Giving an overall view on Delphi’s diverse powertrain product range, Gustanski said, "Delphi's mission is to deliver undiminished vehicle performance while satisfying fuel economy needs and fuel emissions regulations."
Along with the hybrid/ electric vehicle products and advanced gasoline and diesel engine management systems, Delphi showcased fuel handling systems and powertrain cooling solutions.
