| WARF: P03152US |  |
| Variable Valve Actuation Method to Enhance Combustion and Reduce Engine Emissions |
| INVENTORS | • | Rolf Reitz, Christopher Rutland, Rahul Jhavar |
OVERVIEW
In four-stroke engines, intake and exhaust valves open during the engine
cycle to introduce air into the combustion chamber prior to combustion, and to
release exhaust gases once combustion is complete. Valves are typically opened
and closed by a mechanical cam-drive mechanism, with timing dictated by rotation
of the engine’s crankshaft. Recently a new technology has been introduced that
uses an electronically controlled solenoid to open and close valves. Unlike the
mechanical cam system, this variable valve actuation (VVA) technique allows
valves to be opened at chosen times and to varying degrees during the combustion
cycle. The inventors have now devised a way to exploit the flexibility of
VVA in order to reduce pollutant emissions from internal combustion engines.
Their method employs VVA to open valves not only during the intake and
exhaust strokes as in conventional engines, but also at optimal times during the
compression and/or power stokes. Opening the valves at these times promotes
in-chamber turbulence and mixing during combustion, resulting in much greater
soot oxidation. Any unburned fuel or particulates that escape through open
valves via the intake manifold will be ingested during the next engine cycle and
thus won’t contribute to emissions. Also, to reduce loss of combustion chamber
pressure (and thus, engine power) during valve opening, the length of time the
valves are open can be easily minimized with VVA.
KEY BENEFITS
- Promises to reduce soot emissions by accelerating soot oxidation prior to the exhaust stroke
- Provides a much simpler and less expensive method to promote combustion chamber mixing than previous technologies
- Could allow diesel engines to meet tough, new emission standards without the need for after-treatment devices
- Can be readily implemented with other emission control technologies, such as those that reduce nitrogen oxides
- May potentially increase fuel economy
- Applicable to any internal combustion engine
ADDITIONAL INFORMATION
Intellectual Property Status
Tech Fields
Cleantech - Waste & pollution reduction
Cleantech - Low energy processes
Mechanical Engineering - Engines & automotive
CONTACT INFORMATION
For current licensing status, please contact our team at
licensing@warf.org
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