US 12,215,640 B2
Systems and methods for purging fuel in a combustion engine
Michael David Gerstner, Peoria, IL (US); and Arnold Myoungjin Kim, Peoria, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on May 23, 2023, as Appl. No. 18/322,145.
Prior Publication US 2024/0392730 A1, Nov. 28, 2024
Int. Cl. F02D 19/06 (2006.01); F02D 23/02 (2006.01); F02D 41/00 (2006.01)
CPC F02D 19/0621 (2013.01) [F02D 19/0613 (2013.01); F02D 23/02 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An internal combustion engine system, comprising:
an internal combustion engine configured to combust diesel fuel and a second fuel;
a compressor configured to provide a compressed intake air to an intake manifold of the internal combustion engine as part of combustion within a cylinder of the internal combustion engine;
a first fuel pump configured to pump a first fuel from a first fuel tank to a first fuel injector for providing the first fuel, when the first fuel injector is open, to the cylinder;
a second fuel pump configured to pump a second fuel from a second fuel tank to a second fuel injector for providing the second fuel, when the second fuel injector is open, to the intake manifold and into the cylinder for combustion; and
a controller configured to:
receive a purge event notice; and
upon receiving the purge event notice, detect when a differential pressure between the second fuel and the compressed intake air is at or below a value, wherein the value is calculated as a difference between a pressure of the second fuel prior to the second fuel injector and a pressure of the compressed intake air; and
open the second fuel injector when the differential pressure between the second fuel and the compressed intake air is at or below a value to allow the compressed intake air to perform a purge operation to purge at least a portion of the second fuel from the internal combustion engine into the second fuel tank.
 
17. A method of purging an internal combustion engine, comprising:
receiving a purge event notice of the internal combustion engine configured to combust a first fuel, a second fuel, or mixtures thereof, wherein the purge event notice is an indication to a controller to cause the purging of at least a portion of the second fuel from the internal combustion engine;
determining a differential pressure between the second fuel and a compressed intake air is at or below a value, wherein the value is calculated as a difference between a pressure of the second fuel prior to a second fuel injector and a pressure of the compressed intake air; and
upon determining that the differential pressure is at or below the value, performing a purge operation by opening a second fuel injector to allow the compressed intake air to purge at least a portion of the second fuel from the internal combustion engine into a second fuel tank.