HyBoost concept achieving close to Prius-level CO2 emissions; aggressive downsizing with advanced boosting and micro-hybrid system
|HyBoost offers comparable performance to the conventional current 2.0L variant but with fuel economy of a strong hybrid. Click to enlarge.|
The HyBoost demonstrator being developed by Ricardo and its partners (earlier post) is achieving comparable performance to the conventional 2.0L version of its vehicle (a 2009 Ford Focus) but with fuel economy and CO2 emissions approaching those of a Prius, according to David Boggs, Ricardo Technical Specialist, Engines, in a presentation at the recent 2011 Directions in Engine-Efficiency and Emissions Research Conference (DEER) hosted by the Department of Energy in Detroit.
HyBoost achieves this by combining aggressive 50% downsizing of the engine with an electric supercharger for transient low-speed performance, and a micro-hybrid stop-start and energy recuperation systems, Boggs said.
Downsizing the 2.0-liter base engine to a 1-liter, boosted direct injection (EcoBoost) engine delivers up to a 25% reduction. The stop-start system with 6 kW of regenerative braking capability delivers another 10%. Cooled EGR, revised turbo match and the e-boost at the low end provides another 6% reduction, while the use of taller gears and a gearshift advisor chips in another 7% reduction. The HyBoost demonstrator comes in at around 99 g CO2/km but with further system optimization, Boggs said, they can get it down to around 89—the same rating as the Prius.
|Click to enlarge.|
|Ricardo’s gasoline engine roadmap focuses on CO2 reduction through downsizing and the use of synergistic technologies. Click to enlarge.|
Engine downsizing is central to Ricardo’s gasoline engine roadmap for future CO2 and fuel economy improvements. Next-generation spray guided direct injection combustion systems support aggressive engine downsizing with robust stratified engine operation having excellent fuel consumption. A highly tolerant combustion system and knock mitigation are necessary to achieve the very high BMEP levels. The HyBoost vehicle demonstrates the potential to achieve CO2 reduction significantly with cost-effective technologies...the application of synergistic technologies enables high levels of engine downsizing and vehicle fuel economy improvement.—David Boggs
Micro-hybrid market. According to a recent report from Pike Research, sales of vehicles equipped with stop-start systems—one of the synergistic technologies highlighted in the HyBoost concept—will grow rapidly in the coming decade, rising from 3 million units in 2011 to 37.3 million units per year by 2020. By the end of the decade, a total of 186 million vehicles globally will incorporate the technology, which will become standard on the majority of vehicles sold in Europe as well as on dozens of models in North America and Asia, according to the Pike report.
Requiring more robust batteries and starter systems than are found in conventional internal combustion engine (ICE) vehicles, and priced at a small premium over ICEs, stop-start vehicles (SSVs) are considerably less expensive than hybrid electric vehicles (HEVs).
By 2020, stop-start vehicles will represent more than one-third of all light-duty vehicle sales. SSVs are already outselling hybrids globally by a factor of 3.5 to 1, and that gap will widen to a 16 to 1 ratio by 2017 because of the lower cost of SSVs compared to HEVs.—Pike research director John Gartner
Due to stringent emissions regulations, the largest SSV market for the forecast period (to 2020) will be Western Europe, which will represent 98% of the 3 million SSVs sold in 2011. By 2020, Western Europe will account for 42% of all SSVs sold. The fastest-growing region for SSV sales will be North America, where annual sales will roughly double each year from 2011 through 2020, according to Pike. More than two dozen SSV models were available in Western Europe as of early 2011, while in the United States, only three SSV models are for sale.
Application of Synergistic Technologies to Achieve High Levels of Gasoline Engine Downsizing (David Boggs, DEER 2011)