ENGINE COMBUSTION CONTROL VIA FUEL REACTIVITY STRATIFICATION

摘要

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

主权项

1. A compression ignition combustion method for an internal combustion engine, the method including the steps of:
a. providing an initial fuel charge to a combustion chamber sufficiently prior to Top Dead Center (TDC) that the initial fuel charge is at least substantially homogeneously dispersed within the combustion chamber by a time halfway through a compression stroke; b. providing a subsequent fuel charge to the combustion chamber at 40 or more degrees prior to Top Dead Center (TDC):
(1) wherein the subsequent fuel charge and initial fuel charge have different reactivities, and(2) such that the subsequent fuel charge defines a volume within the combustion chamber having different reactivity than the remainder of the combustion chamber; and c. compressing the fuel charges until ignition occurs before the subsequent fuel charge can homogeneously disperse within the combustion chamber.