Method to control the combustion of a compression ignition internal combustion engine with reactivity control through the injection temperature

A method to control the combustion of a compression ignition internal combustion engine (1) with reactivity control through the injection temperature;

• the internal combustion engine (1) is provided with at least one piston (7), which slides, with a reciprocating motion, on the inside of a cylinder (2), so as to carry out a succession of combustion cycles, each comprising at least an intake stroke and a compression stroke;
• the control method comprises the steps of:
• establishing, for each combustion cycle, a quantity (Q) of fuel to be injected into the cylinder (2);
• and
• injecting a first fraction (F1) of the quantity (Q) of fuel at least partially during the intake and/or compression stroke;
• injecting a second fraction (F2) of the quantity (Q) of fuel, which is equal to the remaining fraction of the quantity (Q) of fuel, into the cylinder (2) only at the end of the compression stroke and after the injection of the first fraction (F1) of the quantity (Q) of fuel;
• and
• heating the second fraction (F2) of the quantity (Q) of fuel to an injection temperature (T) of over 100° before injecting the second fraction (F2) of the quantity (Q) of fuel;
• wherein the first fraction (F1) is injected by means of a first fuel injector (9;
• 11) that receives the fuel from a first feed system without active heating devices so that the fraction (F1) of the quantity (Q) of fuel has a temperature below the injection temperature (T);
• wherein the second fraction (F2) of the quantity (Q) of fuel is injected by means of a second fuel injector (8) that is different and independent from the first fuel injector (9;
• 11), injected directly into the cylinder (2), and receives the fuel from a second feed system that is separate and independent from the first feed system;
• wherein the second feed system is provided with at least one active heating device (12;
• 13) that is operated to give the fuel the injection temperature (T);
• and
• wherein the first fraction (F1) of the quantity (Q) of fuel is equal to at least 70% of the quantity (Q) of fuel and the second fraction (F2) of the quantity (Q) of fuel is less than 30% of the quantity (Q) of fuel.

A method to control the combustion of a compression ignition internal combustion engine (1) with reactivity control through the injection temperature;

• the internal combustion engine (1) is provided with at least one piston (7), which slides, with a reciprocating motion, on the inside of a cylinder (2), so as to carry out a succession of combustion cycles, each comprising at least an intake stroke and a compression stroke;
• the control method comprises the steps of:
• establishing, for each combustion cycle, a quantity (Q) of fuel to be injected into the cylinder (2);
• and
• injecting a first fraction (F1) of the quantity (Q) of fuel at least partially during the intake and/or compression stroke;
• injecting a second fraction (F2) of the quantity (Q) of fuel, which is equal to the remaining fraction of the quantity (Q) of fuel, into the cylinder (2) only at the end of the compression stroke and after the injection of the first fraction (F1) of the quantity (Q) of fuel;
• and
• heating the second fraction (F2) of the quantity (Q) of fuel to an injection temperature (T) of over 100° before injecting the second fraction (F2) of the quantity (Q) of fuel;
• wherein the first fraction (F1) is injected by means of a first fuel injector (9;
• 11) that receives the fuel from a first feed system without active heating devices so that the fraction (F1) of the quantity (Q) of fuel has a temperature below the injection temperature (T);
• wherein the second fraction (F2) of the quantity (Q) of fuel is injected by means of a second fuel injector (8) that is different and independent from the first fuel injector (9;
• 11), injected directly into the cylinder (2), and receives the fuel from a second feed system that is separate and independent from the first feed system;
• wherein the second feed system is provided with at least one active heating device (12;
• 13) that is operated to give the fuel the injection temperature (T);
• and
• wherein the value of the fractions (F1, F2) of the quantity (Q) of fuel are established as a function of the rpm of the internal combustion engine (1), the load condition, and the injection temperature (T).