Cylinder cut-out modes for engines
A method of controlling a cylinder cut-out mode for an engine comprising the steps of: a) activating a cylinder cut-out mode in which one or more cylinders of the engine are deactivated; b) while the cylinder cut-out mode is active, monitoring one or more deactivation variables; the one or more deactivation variables comprising one or more of: an inlet manifold air temperature; an engine load factor; an engine speed; and an engine coolant temperature; and c) deactivating the cylinder cut-out mode in order to reactivate any deactivated cylinders when at least one of the deactivation variables exceeds its threshold value.
1. A method of controlling a cylinder cut-out mode for an engine comprising the steps of:
a) activating a cylinder cut-out mode in which one or more cylinders of the engine are deactivated;
b) while the cylinder cut-out mode is active, monitoring one or more deactivation variables; the one or more deactivation variables comprising one or more of:
an inlet manifold air temperature;
an engine coolant temperature; and
c) deactivating the cylinder cut-out mode in order to reactivate any deactivated cylinders when at least one of the deactivation variables exceeds its threshold value.
2. The method of claim 1 , wherein in step b) the step additionally or alternatively comprises monitoring one or more of:
a cylinder's ability to combust fuel; and
receipt of a CAN Bus message indicating an intention to apply load to the engine.
3. The method of claim 1 , wherein in step c) the cylinder cut-out mode is deactivated when any of the deactivation variables exceeds its threshold value.
4. The method of claim 1 , wherein in step a) the cylinder cut-out mode is activated during a cranking mode of the engine and/or an idling mode of the engine.
5. The method of claim 1 , wherein in step b) the cylinder cut-out mode is active during an idling mode of the engine.
6. The method of claim 1 , wherein in step c) when an engine load factor and/or an inlet manifold air temperature exceeds its threshold value the cylinder cut-out mode is deactivated until the engine is stopped and re-started.
7. The method of claim 1 , wherein in step c) when the engine coolant temperature exceeds its threshold value the cylinder cut-out mode is deactivated until the engine coolant temperature reduces below its threshold value, optionally until the engine coolant temperature reduces below its threshold value by a hysteresis amount.
8. The method of claim 1 , wherein in step c) when an engine speed exceeds its threshold value the cylinder cut-out mode is deactivated until the engine speed reduces below its threshold value, optionally until the engine speed reduces below its threshold value for a predetermined period of time.
9. The method of claim 1 , wherein in step c) the cylinder cut-out mode is enabled to go through a predetermined maximum number of deactivation and reactivation cycles due to the engine speed exceeding its threshold value and thereafter a further instance of the engine speed exceeding its threshold value results in the cylinder cut-out mode being deactivated until the engine is stopped and re-started.
10. The method of claim 1 , wherein the engine is a diesel engine, optionally a diesel genset engine.
11. The method of claim 1 , wherein an ambient temperature surrounding the engine is less than 10° C.
12. The method of claim 1 , wherein in step b) the step additionally comprises monitoring one or more of:
an engine load factor; and
an engine speed.
13. An engine comprising a plurality of cylinders and a controller, the controller being enabled to activate a cylinder cut-out mode in which one or more of the plurality of cylinders are deactivated;
the controller being configured to:
a) activate the cylinder cut-out mode;
b) monitor one or more deactivation variables while the cylinder cut-out mode is active; the one or more deactivation variables comprising one or more of:
an inlet manifold air temperature; and
an engine coolant temperature; and
c) deactivate the cylinder cut-out mode in order to reactivate any deactivated cylinders when at least one of the deactivation variables exceeds its threshold value.
14. The engine of claim 13 , wherein in step b) the controller is additionally or alternatively configured to monitor one or more of:
a cylinder's ability to combust fuel; and
receipt of a CAN Bus message indicating an intention to apply load to the engine.
15. The engine of claim 14 , wherein the engine is a diesel engine, optionally a diesel genset engine.
16. The engine of claim 13 , wherein in step b) the controller is additionally configured to monitor one or more of:
an engine load factor; and
an engine speed.
17. A controller for controlling a cylinder cut-out mode of an engine, the controller being configured to:
a) activate the cylinder cut-out mode;
b) monitor one or more deactivation variables while the cylinder cut-out mode is active; the one or more deactivation variables comprising one or more of:
an inlet manifold air temperature; and
an engine coolant temperature; and
c) deactivate the cylinder cut-out mode in order to reactivate any deactivated cylinders when at least one of the deactivation variables exceeds its threshold value.
18. The controller of claim 17 , wherein in step b) the controller is additionally or alternatively configured to monitor one or more of:
a cylinder's ability to combust fuel; and
receipt of a CAN Bus message indicating an intention to apply load to the engine.
19. The controller of claim 17 , wherein in step b) the controller is additionally configured to monitor one or more of:
an engine load factor; and
an engine speed.