MAHLE Jet Ignition for Ferrari F1 as well as sub-200 g/kWh BSFC in light-duty engine; on-road and stationary applications
MAHLE Powertrain has been developing Jet Ignition—a high-energy distributed ignition technology that enables homogeneous ultra-lean (λ > ∼1.6) combustion, with its attendant benefits of reduced fuel consumption and emissions—for a number of years. (E.g., Earlier post, (Earlier post.)
MAHLE Jet Ignition (MJI) uses a pre-chamber in conjunction with a spark plug and secondary fuel injector. The chemical, thermal and kinetic energy from the combustion of this small fuel-air mixture is transferred via nozzles to the main combustion chamber where it ignites the main fuel-air mixture.
|Left. Rendering of the pre-chamber assembly. Right. Rendering of the pre-chamber assembly in cylinder head. Source: Bunce and Blaxill (2016). Click to enlarge.|
As part of a long-term technical partnership with Scuderia Ferrari, MAHLE is providing Ferrari’s Formula 1 division with Jet Ignition and the lean burn combustion process. MAHLE Powertrain, in cooperation with the US Department of Energy, has demonstrated that MAHLE Jet Ignition can deliver impressive results in passenger car applications.
The technology has demonstrated sub-200 g/kW-hr brake specific fuel consumption, peak brake thermal efficiency above 41.5%, and 95+ % reductions in engine-out NOx levels with a multi-cylinder engine, all while reducing knock and maintaining acceptable levels of combustion stability. A 10-20% increase in fuel economy (mpg) is expected when compared to current production gasoline engines.
In a paper presented at the 2016 SAE World Congress, Mahle engineers detailed the experimental results from single-cylinder and multi-cylinder engines incorporating the jet igniter in support of the above figures.
The results presented are achieved with the MJI combustion concept and as such are applicable to jet ignition concepts generally. A fully optimized jet ignition engine must incorporate multiple criteria including desired peak power, boost strategy, and geometric compression ratio. Cost-benefit analyses will be performed for multiple MJI engine operation scenarios. Further MJI development activities include cold start development, boost system selection, and aftertreatment specification.—Bunce and Blaxhill (2016)
MAHLE Jet Ignition also can increase fuel efficiency for natural gas and LPG powerplants. In cooperation with ARPA-E, the advanced research projects agency on energy of the US Dept. of Energy, MAHLE Powertrain is developing Jet Ignition for a natural-gas-fueled combined heat and power (CHP) unit.
The goal is to produce a micro-CHP unit that meets both electrical and heating needs for a residential site that not only reduces greenhouse gas emissions but also is competitive with traditional electrical grid power pricing.
Combining the high fuel efficiency of MAHLE Jet Ignition with MAHLE friction reduction technologies and systems expertise, an ultra-high efficiency, long life, low life-cycle cost micro-CHP unit is conceivable and is a key to opening this emerging market in the US, MAHLE said.
MAHLE continues to develop the technology for high specific power, high efficiency, low emissions, and off-road applications as well.
MAHLE’s design distributes the high-energy jets deep into the main combustion chamber, which significantly reduces knock, useful for motorsport applications, and also enables ignition of very lean mixtures for high fuel economy applications.—Hugh Blaxill, general manager, MAHLE Powertrain LLC
Bunce, M. and Blaxill, H. (2016) “Sub-200 g/kWh BSFC on a Light Duty Gasoline Engine,” SAE Technical Paper 2016-01-0709 doi: 10.4271/2016-01-0709