DOE OSTI2019
This document details the work completed during Project DE-EE0006839 ‘Ultra Efficient Light Duty Powertrain with Gasoline Low Temperature Combustion’. All tasks from the project’s Statement of Project Objectives are discussed. Final demonstration data is also presented and discussed. Further project details can be found in the Quarterly Technicial Reports that were submitted during the course of the project and are stored on the EERE Project Management Center Website. The goal of this project was to develop, implement and demonstrate a low temperature combustion approach called Gasoline Direct Injection Compression Ignition (GDCI) that provides high thermal efficiency with low NOx and PM emissions. The project target was to demonstrate a 35% fuel economy improvement over the baseline vehicle while meeting Tier 3 emissions levels. At the start of this project, GDCI was a moderately mature combustion technology, due in large part to advances made during a Delphi Technologies program funded through an earlier Department of Energy Advanced Technology Powertrains (ATP) opportunity; under that earlier contract, DE-EE0003258, Delphi Technologies assembled a team with complementary industrial and academic experience, and led this team to advance the technology from the original fundamental work to the state of art embodied by a first-generation (Gen 1) multi-cylinder GDCI engine. Key activities during that project centered on engine and combustion chamber design, and development of fuel injection equipment, valvetrain and advanced controls. Performance results with the Gen 1 engine in a development vehicle demonstrated that GDCI had the capability to operate using Low Temperature Combustion (LTC) over a broad speed-load range. Based on benchmarking work, efficiency for the Gen 1 GDCI engine compared favorably overall to production light-duty diesel engines. The second DOE funded project, DE-EE0006839, focused on a number of technical risks and issues that were left to be resolved for GDCI to become a production-viable technology. These risks were:GDCI combustion system refinement to achieve near-ideal air/fuel mixture preparation for high efficiency and low HC and CO emissions; Transient control development for low temperature combustion with high EGR levels during real-world transient driving maneuvers and over a broader range of ambient conditions; Aftertreatment system design that is effective in dealing with the low-temperature challenges of a highly efficient engine. The project was executed in two phases. Phase 1 leveraged the development vehicle from the Advanced Technologies Powertrain 1 (ATP1) project, DE-EE0003258. That vehicle was used as an initial test bed in the development of a high performance low temperature exhaust aftertreatment system. The vehicle was also used to develop calibration refinements for improved exhaust emissions and fuel efficiency. Samples of a new GDCI development level engine, called Gen2 GDCI (and developed outside of the first DOE funded project), were also used during Phase 1 to develop refined controller hardware and control algorithms, as well as improved sensors and actuators. The Gen2 engine was then retrofitted into the development vehicle from the ATP1 project and used for controls refinement and calibration of GDCI to achieve improved cold start, drivability and robustness to real world environments and fuel variations. During Phase 2 of the project, Gen3 versions of the GDCI engine were designed and built specifically for this project based on experience from the earlier engines. These engines were designed to be production-like in construction and, when combined with refined control systems and project specific low temperature exhaust aftertreatment, were intended to support the goal of meeting Tier 3 emissions levels at a vehicle level. Though great progress had been made advancing the GDCI combustion process, and despite extensive presentations of our work on the technology at various conferences and in direct meetings with automotive companies, none of the US domestic automotive OEMs had shown an interest in adopting this combustion process as part of their technology planning as the project approached the Go/No-Go point at the end of Budget Period 3. As a result of this low-level of interest both the US Department of Energy and Delphi Technologies received in this technology from domestic auto manufactures, Delphi Technologies elected a ‘No-Go’ status for the gate between Budget Period 3 and Budget Period 4 which terminated the project without spending any Budget Period 4 funds. The project team concluded that the dynamometer mapping of the most recent level of hardware, combined with the vehicle level simulation by Argonne National Laboratory, was sufficient to document the capabilities and potential of the combustion process without spending the time and money to do the controls development and full calibration necessary for a demonstration vehicle.
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