US 11,815,054 B2
Dual fuel system having dual fuel injector and engine operating method
Eric Lee Schroeder, Germantown Hills, IL (US); David Todd Montgomery, Edelstein, IL (US); Dana Ray Coldren, Secor, IL (US); and Chad Koci, Washington, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on Jun. 3, 2022, as Appl. No. 17/831,668.
Application 17/831,668 is a division of application No. 17/167,211, filed on Feb. 4, 2021, granted, now 11,384,721.
Prior Publication US 2022/0290641 A1, Sep. 15, 2022
Int. Cl. F02M 43/04 (2006.01); F02D 19/06 (2006.01); F02D 19/10 (2006.01); F02M 47/02 (2006.01)
CPC F02M 43/04 (2013.01) [F02D 19/0694 (2013.01); F02D 19/0649 (2013.01); F02D 19/10 (2013.01); F02M 47/027 (2013.01); F02M 2200/46 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of operating an engine comprising:
admitting a liquid pilot fuel into a pilot fuel passage in a fuel injector;
displacing a liquid primary fuel in a primary fuel passage in the fuel injector with liquid pilot fuel from the pilot fuel passage to form a segmented fuel charge of leading pilot fuel and trailing primary fuel in the primary fuel passage;
increasing a fluid pressure in the primary fuel passage to an injection pressure after the formation of the segmented fuel charge;
opening an outlet check in the fuel injector to inject the segmented fuel charge into a combustion cylinder in the engine; and
igniting, within the combustion cylinder, the liquid primary fuel of the segmented fuel charge based on compression-ignition of the liquid pilot fuel of the segmented fuel charge.