Method for starting an internal combustion engine
A method for starting an internal combustion engine comprises the steps of: providing an internal combustion engine having at least one cylinder and a piston supported at a crankshaft for repeated reciprocal movement in the cylinder so as to define a main combustion chamber, the internal combustion engine further having an ignition device arranged in said cylinder with an igniter portion and a fuel injector which are both arranged at a pre-chamber, wherein the pre-chamber has a plurality of orifices for providing fluid communication between said pre-chamber and the main combustion chamber, injecting fuel in the pre-chamber, and igniting the injected fuel in the pre-chamber for pre-heating of the pre-chamber prior to injecting fuel in the main combustion chamber for combusting the injected fuel in the main combustion chamber.
1. A method for starting an internal combustion engine comprising the steps of:
providing an internal combustion engine having at least one cylinder and a piston supported at a crankshaft for repeated reciprocal movement in the cylinder so as to define a main combustion chamber, the internal combustion engine further having an ignition device arranged in said cylinder with an igniter portion and a fuel injector which are both arranged at a pre-chamber, wherein the pre-chamber has a plurality of orifices for providing fluid communication between said pre-chamber and the main combustion chamber;
injecting fuel in the pre-chamber at the start of an engine cycle so that the lambda value λ in the pre-chamber is less than 1;
subsequently igniting the injected fuel in the pre-chamber, thereby pre-heating the pre-chamber prior to a compression of the piston in the cylinder in said engine cycle, and causing combustion jets to exit the pre-chamber via the plurality of orifices and enter the main combustion chamber; and
subsequent to pre-heating of the pre-chamber, injecting fuel in the main combustion chamber in said engine cycle so that the lambda value λ in the main combustion chamber is less than 1.6, wherein the combustion jets cause combustion of the injected fuel in the main combustion chamber.
2. The method according to claim 1 , wherein the step of injecting fuel in the pre-chamber comprises injecting fuel in the pre-chamber only.
3. The method according to claim 2 , wherein the step of injecting fuel in the pre-chamber comprises multiple injections of fuel via fuel injector in the pre-chamber.
4. The method according to claim 3 , wherein the step of igniting the injected fuel in the pre-chamber is carried out in between subsequent multiple injections of fuel in the pre-chamber.
5. The method according to claim 1 , wherein the injection of fuel in the pre-chamber and the ignition of the injected fuel in the pre-chamber are carried out after a predetermined time duration T starting from the injection of fuel in the pre-chamber.
6. The method according to claim 1 , wherein the injection of fuel in the pre-chamber and the ignition of the injected fuel in the pre-chamber are carried out after a predetermined angular movement of rotating engine components.
7. The method according to claim 1 , wherein the injection of fuel in the pre-chamber and the ignition of the injected fuel in the pre-chamber are carried out prior to a first compression move of the piston in the cylinder.
8. The method according to claim 1 , wherein the injection of fuel in the pre-chamber and the ignition of the injected fuel in the pre-chamber are carried out at different individual angular positions of the rotating engine components for a predetermined time interval t.
9. The method according to claim 1 , wherein the injection of fuel in the pre-chamber and the ignition of the injected fuel in the pre-chamber is carried out at a continuous range of angular positions a of the crankshaft.
10. The method according to claim 1 , wherein the injection of fuel in the pre-chamber and the ignition of the injected fuel in the pre-chamber are carried out prior to a movement of the crankshaft.
11. The method according to claim 1 , wherein the amount of injected fuel in the pre-chamber is chosen so that the air/fuel ratio λ is less than 1.
12. The method according to claim 1 , further comprising the step of injecting fuel in the pre-chamber comprises the step of simultaneously injecting fuel in the main combustion chamber.
13. The method according to claim 12 , wherein the amount of injected fuel in the main combustion chamber is chosen so that the air/fuel ratio λ is less than 1 in the main combustion chamber.