For immediate release
Detroit — April 8, 2014 — Southwest Research Institute® (SwRI) announced preliminary test results of its patented Dedicated Exhaust Gas Recirculation (D-EGR®) demonstration vehicle today at the SAE World Congress. The results prove the advanced combustion technology increases engine efficiency while simultaneously lowering exhaust emissions.
Dedicated EGR is a novel engine architecture up to 15 percent more efficient than today’s mainstream engines while simultaneously improving performance. It allows manufacturers to address future, more aggressive Corporate Average Fuel Economy (CAFE) standards and meet LEV III/Tier 3 emissions levels cost-effectively.
SwRI’s D-EGR demonstration vehicle began as a mid-size sedan with a current-production 4-cylinder 2.0 L gasoline engine. The engine was modified so that exhaust from one dedicated cylinder is run with a rich mixture of fuel and air to reform hydrocarbon fuel into carbon monoxide and hydrogen. The reformulated exhaust gas is then cooled and looped into a patented mixer where the EGR and reformate are mixed with fresh air before going into the engine intake. A team of engineers designed several new parts for the advanced combustion concept — the cooled EGR loop, the EGR mixer and high-energy ignition system — as well as engine-control software that enables in-cylinder fuel reformation.
“The D-EGR concept takes the best attributes of regular cooled EGR and combines them with in-cylinder reformer technology. We segregate the exhaust of a cylinder of the engine so that one cylinder provides all of the recirculated exhaust gas back into the intake manifold,” said Dr. Terry Alger, assistant director in SwRI’s Engine, Emissions and Vehicle Research Division.
“By running one cylinder rich, the excess fuel is reformed into hydrogen and carbon monoxide,” added Chris Chadwell, manager of SwRI’s Spark Ignition Engine R&D section. “The in-cylinder reformation slightly reduces the carbon dioxide and water vapor while producing large volumes of carbon monoxide, which is a good fuel, and hydrogen, which is an outstanding fuel. That provides an octane boost and a flammability boost, and extends the EGR limit of the engine.”
Designed from the start to demonstrate production feasibility, a D-EGR-configured engine can be integrated into almost any spark-ignited engine architecture. Because there are few additional components, it fits comfortably in an existing engine compartment without altering the engine’s footprint.
“Our engineers initially developed and demonstrated D-EGR technology in an engine test cell through SwRI’s HEDGE® (High-Efficiency Dilute Gasoline Engine) consortia,” said SwRI Executive Vice President Walt Downing. “Under SwRI’s internal research program, our engineers were able to solve the technical problems with making a D-EGR engine fit under the hood and operate on a current-production sedan. In 15 months, we took the concept from the laboratory to production viability.”
By 2025, automobile manufacturers will have to meet CAFE standards of 54.5 miles per gallon. The Environmental Protection Agency is also expected to release new, more stringent emissions standards. Those two factors mean there is considerable industry focus on simultaneously improving both emissions and fuel efficiency, challenges which SwRI’s demonstration vehicle addresses.
“When considering the high-efficiency alternatives out there today, we feel that our Dedicated EGR technology is not only a high-efficiency, low-emissions alternative, but it’s the most cost-effective market-ready solution currently available,” Alger said.