US 7,627,416 B2 · Method and apparatus for operating a dual fuel internal combustion engine

Abstract

In an internal combustion engine that can burn two fuels, the main fuel may become unavailable, either temporarily or until the main fuel is replenished. The present apparatus determines when to fuel an engine with main fuel and secondary fuel, or secondary fuel alone. The apparatus includes a main-fuel supply system comprising a main-fuel injection valve that introduces main fuel into an engine combustion chamber; a secondary-fuel injection system comprising a secondary-fuel injection valve that introduces secondary fuel directly into the combustion chamber; a pressure sensor associated with the main-fuel supply system for determining injection pressure inside the main-fuel injection valve; and an electronic controller in communication with the pressure sensor and programmable to separately command actuation of the secondary-fuel and the main-fuel injection valve when injection pressure is greater than a predetermined threshold, and to otherwise command actuation of the secondary-fuel injection valve and not the main-fuel injection valve.

Claims24

Dependent claims

An apparatus is provided for determining when to fuel an internal combustion engine with main fuel and secondary fuel or secondary fuel alone, said apparatus comprising:

(a) a main-fuel supply system comprising a main-fuel injection valve that is operable to introduce said main fuel into a combustion chamber of said engine;
(b) a secondary-fuel injection system comprising a secondary-fuel injection valve that is operable to introduce said secondary fuel directly into said combustion chamber;
(c) a pressure sensor associated with said main-fuel supply system for determining an available injection pressure inside said main-fuel injection valve;
and
(d) an electronic controller in communication with said pressure sensor and programmable to separately command actuation of said secondary-fuel injection valve and said main-fuel injection valve to permit said engine to operate at power levels up to full power when said available injection pressure is greater than a predetermined threshold and to otherwise command actuation of said secondary-fuel injection valve and not said main-fuel injection valve to permit said engine to operate at reduced power levels less than full power for up to a predetermined amount of time.

2 more elements

A method of determining when to fuel an internal combustion engine with main fuel and secondary fuel or secondary fuel alone, said method comprising:

(a) measuring available injection pressure of said main fuel;
(b) operating in a dual fuel mode in which said engine is operable at power levels up to full power, by fuelling said engine with said main fuel and said secondary fuel with commanded quantity and injection timing for each fuel determined based upon engine speed and engine load, when said available injection pressure is above a predetermined threshold pressure;
and
(c) operating in a secondary fuel mode in which said engine is operable at reduced power levels less than full power for up to a predetermined amount of time, by fuelling said engine with secondary fuel alone with commanded quantity and injection timing based upon engine speed and load.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for operating a dual fuel internal combustion engine

Life of this patent

Method and apparatus for operating a dual fuel internal combustion engine

Life of this patent

Abstract

Claims24