Extending Lean Limit with Mass-Timed Compression Ignition Using a Catalytic Plasma Torch
Research on the Catalytic Plasma Torch (CPT) ignition system was conducted this last year at BKM, Inc. in San Diego. The results showed that under certain conditions CPT can not only time ignition properly, but also extend the lean stability limit. This concept is based upon compression ignition of the charge in the CPT's integral pre-chamber. Compression ignition is induced by timed catalytic reduction of the pre-chamber's activation energy. This produces almost instantaneous combustion in the pre-chamber and is divided into multiple high velocity torches to rapidly ignite the main chamber charge. The timing of the ignition event is based on the location of the heated catalyst in the pre-chamber and the mass of the charge inducted into the cylinder. The base timing curve can be modified via current control which effects the catalyst activity. Dynamic modification of the timing event is accomplished by using the catalyst as an in-cylinder hot wire anemometer.