Patent ID: 6289871
Filing Date: 2001-09-18
Classification: F02D,Y02T

Abstract:
A method for controlling the delivery of liquid pilot fuel to each cylinder of a dual fuel engine wherein each cylinder includes at least one controllable liquid fuel injector for delivering liquid pilot fuel to such cylinder, the method comprising the steps of:(a) operating the dual fuel engine in a dual fuel mode;(b) selecting a cylinder of the dual fuel engine;(c) establishing a first predetermined incremental amount of liquid pilot fuel;(d) establishing a first predetermined incremental change in a cylinder performance parameter for the selected cylinder;(e) reducing delivery of liquid pilot fuel to the selected cylinder by the first predetermined incremental amount established in step (c);(f) comparing a change in the cylinder performance parameter as a result of the incremental reduction of liquid pilot fuel in step (e) with the first predetermined incremental change in the cylinder performance parameter established in step (d);(g) repeating steps (e) and (f) so as to successively reduce delivery of liquid pilot fuel to the selected cylinder until the change in the cylinder performance parameter is greater than the first predetermined incremental change in such parameter established in step (d);(h) establishing a second predetermined incremental amount of liquid pilot fuel;(i) establishing a second predetermined incremental change in the cylinder performance parameter for the selected cylinder;(j) increasing delivery of liquid pilot fuel to the selected cylinder by the second predetermined incremental amount established in step (h);(k) comparing a change in the cylinder performance parameter as a result of the incremental increase of liquid pilot fuel in step (j) with the second predetermined incremental change in the cylinder performance parameter established in step (i);(l) repeating steps (j) and (k) so as to successively increase delivery of liquid pilot fuel to the selected cylinder until the change in the cylinder performance parameter is less than the second predetermined incremental change in such parameter established in step (i) at which point an amount of liquid pilot fuel being delivered to the selected cylinder is established as a desired amount;(m) maintaining delivery of the desired amount of liquid pilot fuel established in step (l) to the selected cylinder; and(n) controlling the delivery of liquid pilot fuel to each of the remaining cylinders of the dual fuel engine in accordance with steps (a) through (m) for each successive cylinder.