Combustion control and sensors: a review

A converter containing a NOx absorbing and reducing catalyst is disposed in the exhaust passage of an internal combustion engine. The upstream half portion (portion of the inlet side) of the substrate of the NOx absorbing and reducing catalyst in the converter carries the oxygen storage component that absorbs oxygen in the exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases the absorbed oxygen when the air-fuel ratio of the exhaust gas flowing in is rich in addition to carrying the NOx absorbing and reducing catalyst. After NOx is absorbed by the NOx absorbing and reducing catalyst as a result of operating the engine at a lean air-fuel ratio, the engine is operated at a rich air-fuel ratio, so that NOx is released from the NOx absorbing and reducing catalyst and is purified by reduction. Here, oxygen is released from the oxygen storage component carried by the upstream half portion of the substrate and is reacted with the H 2 and CO components in the exhaust gas, so that the temperature of the NOx absorbing and reducing catalyst is raised within short periods of time due to the heat of reaction. Therefore, the catalyst exhibits increased activity and the NOx absorbing and reducing catalyst exhibits improved NOx purification capability.

Exhaust gas purification device for an internal combustion engine

Cyclic Variability in Spark Ignition Engines A Literature Survey

Monolith structures, materials, properties and uses

The present invention provides a reliable, high-repetition rate, production line compatible high energy photon source. A very hot plasma containing an active material is produced in vacuum chamber. The active material is an atomic element having an emission line within a desired extreme ultraviolet (EUV) range. A pulse power source comprising a charging capacitor and a magnetic compression circuit comprising a pulse transformer, provides electrical pulses having sufficient energy and electrical potential sufficient to produce the EUV light at an intermediate focus at rates in excess of 5 Watts. In preferred embodiments designed by Applicants in-band, EUV light energy at the intermediate focus is 45 Watts extendable to 105.8 Watts.

Extreme ultraviolet light source

A method and apparatus for desulfating a NO x trap is proposed wherein the SO x purge temperature is achieved by modulating the amplitude of the A/F of the mixture supplied to the engine thereby storing oxygen in the trap during lean engine cylinder events and generating the required exotherm during rich engine cylinder events.

Method and apparatus for desulfating a NOx trap

An ignition system for a stratified charge internal combustion engine is disclosed. The engine has at least one combustion chamber and a fuel injection means effective to inject fuel in a conical spray pattern into a predetermined zone of the combustion chamber for establishing a stratified charge. The system has walls dening a plasma ionizing chamber with an outlet orifice, electrical discharge means to apply an electrical charge across the plasma ionizing chamber causing the contents thereof to be shock heated to an ionized condition and released through the outlet orifice as a jet, and means interrupting the outlet orifice to form said plasma jet into a hollow cone and to direct the conical jet into the zone of the injected fuel.

Ignition system employing plasma spray

A method of optimizing vehicle emissions during lean engine operation is disclosed wherein an emission control device receiving engine exhaust gases is filled with one or more constituent gases of the exhaust gas to a predetermined fraction of the device storage capacity, and is then completely emptied during a subsequent purge. As the device storage capacity is substantially reduced, as indicated by an actual fill time becoming equal to or less than a predetermined minimum fill time, a device regeneration cycle is performed to attempt to restore device capacity. A programmed computer controls the fill and purge times based on the amplitude of the voltage of a switching-type oxygen sensor and the time response of the sensor. The frequency of the purge, which ideally is directly related to the device capacity depletion rate, is controlled so that the device is not filled beyond its storage capacity limit.

Method and system for optimizing open-loop fill and purge times for an emission control device

This paper demonstrates the first successful use of factorial statistical analysis in quantifying the effect of ignition system parameters on lean operation of a fast burn single cylinder engine. Ignition parameters investigated include plug type, plug number, ignition system, plug location, and ground electrode orientation with respect to the mean swirl generated flow direction. System performance is quantified by analyzing the coefficient of variance of the peak cylinder pressure and the 0-10% mass fraction burn time for various parameter combinations. To confirm the results from the factorial analysis technique, data from spark angle sweeps at constant flowrates are presented for the basic system and for two promising candidates that were selected from the factorial experiments. These candidates, a multi-ground electrode plug and a surface-air gap plug combined with more ignition energy, are shown to improve engine operation at lean gas-to-fuel ratio. Finally, a simplified thermodynamic engine model is utilized to predict what specific fuel consumption (ISFC) is attainable with stable operation at lean gas-to-fuel ratio. The value measured at the MBT+1% ISFC level, using the surface-air gap plug and more ignition energy at about 22:1 gas-to-fuel ratio, is found to be within experimental error of the predicted value.

Ignitability experiments in a fast burn, lean burn engine

A capacitor discharge ignition system for a spark-ignition internal combustion engine. The ignition system includes an ignition coil having first and second primary windings, a secondary winding and a ferromagnetic core about which the windings are wound. A spark plug has electrodes which are spaced apart to form a spark gap which is connected in series with a first capacitor. The series-connected spark gap and first capacitor are connected across the secondary winding. A second capacitor is coupled to the first winding and a DC source of electrical energy is provided. First circuit means charge the second capacitor from the DC source and discharge this capacitor through the first primary winding in timed relation to operation of the engine. Second circuit means are provided for producing a fixed frequency oscillatory current in the second primary winding for a predetermined time interval subsequent to each discharge of the second capacitor through the first primary winding. The discharge of the second capacitor through the first primary winding and the subsequent supply of fixed frequency oscillatory current to the second primary winding causes ferroresonant oscillations in the secondary circuit of the ignition coil for at least a portion of the aforementioned predetermined time interval. The spark which occurs between the spark plug electrodes exists during the predetermined time interval and has a duration which may be varied as desired.

Joseph R. Asik

Papers

Method and apparatus for desulfating a NOx trap

Ignition system employing plasma spray

Method and system for optimizing open-loop fill and purge times for an emission control device

Ignitability experiments in a fast burn, lean burn engine

Capacitor discharge ignition system with controlled spark duration