초록 ▼

A piston engine and a method for controlling a diesel-type piston engine including at least one combustion chamber formed by a cylinder, a movably arranged piston in each cylinder, which piston is connected to a crankshaft, an injection device designed to inject fuel directly into the combustion cha

A piston engine and a method for controlling a diesel-type piston engine including at least one combustion chamber formed by a cylinder, a movably arranged piston in each cylinder, which piston is connected to a crankshaft, an injection device designed to inject fuel directly into the combustion chamber and turbo system comprising a low pressure turbo and a high pressure turbo. The thermal efficiency of the internal combustion is increased while requirements relating to nitrogen oxide and soot particle emissions continue to be maintained.

대표청구항 ▼

What is claimed is: 1. A method for controlling a diesel-type piston engine comprising at least one combustion chamber formed by a cylinder (52) and a movably arranged piston (53) in each cylinder that is connected to a crankshaft (54), an injection device (56) configured to inject fuel directly in

What is claimed is: 1. A method for controlling a diesel-type piston engine comprising at least one combustion chamber formed by a cylinder (52) and a movably arranged piston (53) in each cylinder that is connected to a crankshaft (54), an injection device (56) configured to inject fuel directly into the combustion chamber, and a turbo system comprising a low-pressure turbo (22) and a high-pressure turbo (18) disposed downstream of the low-pressure turbo (22), the low-pressure turbo (22) and high-pressure turbo (18) each having a turbo map efficiency greater than 60%, the method comprising utilizing a control mechanism for gas exchange valves (57, 58) to establish at least a first operating range for the internal combustion engine at a mean piston velocity greater than 6 m/s and at an engine load greater than 15 bar BMEP at which the volumetric efficiency within said first operating range is less than 70%. 2. The method as recited in claim 1, wherein said low-pressure turbo (22) and high-pressure turbo (18) each have a turbo map efficiency greater than 65%. 3. The method as recited in claim 1, wherein said low-pressure turbo (22) and high-pressure turbo (18) each have a turbo map efficiency greater than 70%. 4. The method as recited in claim 1, further comprising controlling the gas exchange valves (57, 58) fitted to said combustion chamber to affect engine operation within an operating range with a load between 5 and 30 bar BMEP and for mean piston velocities between 5 and 7.5 m/s and thereby providing a volumetric efficiency less than 85%. 5. The method as recited in claim 4, wherein the gas exchange valves (57, 58) fitted to the combustion chamber are controlled to provide a volumetric efficiency which varies between 45% and 85% in dependence on the operating state of the engine. 6. The method as recited in claim 1, wherein the closure inlet valves (57) fitted to said combustion chamber varies in dependence on the operating state of the internal combustion engine. 7. The method as recited in claim 1, wherein the inlet valves (57) fitted to said combustion chamber are closed before or after the closing time which generates maximum volumetric efficiency for the internal combustion engine. 8. The method as recited in claim 1, further comprising controlling the injection of fuel from said injection device (56) to a specific injection time less than 0.1 crank angle degrees/(bar*m/s) within an operating range for the internal combustion engine with an engine load greater than 7 bar BMEP. 9. The method as recited in claim 1, further comprising controlling the injection of fuel from said injection device (56) to a specific injection time less than 0.095 crank angle degrees/(bar*m/s) within an operating range for the internal combustion engine with an engine load greater than 12 bar BMEP. 10. The method as recited in claim 1, further comprising controlling the injection of fuel from said injection device (56) to a specific injection time less than 0.095 crank angle degrees/(bar*m/s) within an operating range for the internal combustion engine with a mean piston velocity greater than 6 m/s. 11. The method as recited in claim 1, further comprising controlling the injection of fuel from said injection device (56) to a specific injection time less than 0.09 crank angle degrees/(bar*m/s) within an operating range for the internal combustion engine with an engine load greater than 18 bar BMEP. 12. The method as recited in claim 1, further comprising adjusting the air and fuel supply to said combustion chamber to provide an equivalent air excess factor (λ) within the range 1.7-2.05 at an engine load within the range 18-30 bar BMEP. 13. The method as recited in claim 1, further comprising controlling the fuel supply to be initiated within the range 0 to 10 crank angle degrees before upper dead center. 14. The method as recited in claim 1, wherein the maximum injection pressure of the injection device (46) is controlled to be greater than 1600 bar. 15. The method as recited in claim 1, wherein the ratio between the highest needle opening pressure NOP and the maximum injection pressure maxIP is greater than 0.7. 16. The method as recited in claim 1, wherein injection is realized through an injection nozzle having more than 6 holes. 17. The method as recited in claim 1, wherein a charge-air cooler (27) is disposed between said low-pressure turbo and high-pressure turbo. 18. The method as recited in claim 1, wherein exhaust gases from the combustion process in said combustion chamber pass through an at least partially heat-insulated exhaust duct. 19. The method as recited in claim 1, further comprising adjusting the air and fuel supply to said combustion chamber to allow a maximum cylinder pressure during combustion greater than 8*BMEP. 20. The method as recited in claim 19, further comprising adjusting the air and fuel supply to the combustion chamber to allow a maximum cylinder pressure during combustion greater than 9*BMEP. 21. The method as recited in claim 20, further comprising adjusting the air and fuel supply to said combustion chamber to allow a maximum cylinder pressure during combustion greater than 10*BMEP. 22. A diesel-type piston engine comprising at least one combustion chamber formed by a cylinder (52) and a movably arranged piston (53) in each cylinder that is connected to a crankshaft (54), an injection device (56) configured to inject fuel directly into said combustion chamber, and a turbo system comprising a low-pressure turbo (22) and a high-pressure turbo (18) which is disposed downstream of said low-pressure turbo (22), said low-pressure turbo (22) and high-pressure turbo (18) each have a turbo map efficiency greater than 60%, and further comprising a control mechanism of gas exchange valves (57, 58) that is configured to provide at least a first operating range for the internal combustion engine at a mean piston velocity greater than 6 m/s and at an engine load greater than 15 bar BMEP, in which the volumetric efficiency within said first operating range is less than 70%. 23. The piston engine as recited in claim 22, wherein said low-pressure turbo (22) and high-pressure turbo (18) each have a turbo map efficiency greater than 65%. 24. The piston engine as recited in claim 22, wherein said low-pressure turbo (22) and high-pressure turbo (18) each have a turbo map efficiency greater than 70%. 25. The piston engine as recited in claim 22, where the gas exchange valves (57, 58) are fitted to said combustion chamber are configured to be controlled so as, within an operating range for the internal combustion engine with a load between 5 and 30 bar BMEP and for mean piston velocities between 5 and 7.5 m/s, to provide a volumetric efficiency less than 85%. 26. The piston engine as recited in claim 25, where the gas exchange valves (57, 58) are fitted to said combustion chamber and configured to be controlled to provide a volumetric efficiency which varies between 45% and 85% in dependence on the operating state of the engine. 27. The piston engine as recited in claim 22, wherein the closure of inlet valves (57) fitted to said combustion chamber is configured to vary in dependence on the operating state of the internal combustion engine. 28. The piston engine as recited in claim 22, wherein inlet valves (57) fitted to said combustion chamber are configured to be closed before or after the optimum for volumetric efficiency for the internal combustion engine. 29. The piston engine as recited in claim 22, wherein inlet valves (57) fitted to said combustion chamber are configured to be closed before or after lower dead center. 30. The piston engine as recited in claim 22, wherein the closing time of inlet valves (57) fitted to said combustion chamber varies in dependence on the operating state of the internal combustion engine. 31. The piston engine as recited in claim 22, wherein said injection device (56) is configured to have a specific injection time less than 0.12 crank angle degrees/(bar * m/s) within an operating range for the internal combustion engine with an engine load greater than 7 bar BMEP. 32. The piston engine as recited in claim 22, wherein said injection device (56) is configured to have a specific injection time less than 0.095 crank angle degrees/(bar*m/s) within an operating range for the internal combustion engine with an engine load greater than 12 bar BMEP. 33. The piston engine as recited in claim 22, wherein said injection device (56) is configured to have a specific injection time less than 0.095 crank angle degrees/(bar*m/s) within an operating range for the internal combustion engine with a mean piston velocity greater than 6 m/s. 34. The piston engine as recited in claim 22, wherein said injection device (56) is configured to have a specific injection time less than 0.09 crank angle degrees/(bar*m/s)within an operating range for the internal combustion engine with an engine load greater than 18 bar BMEP. 35. The piston engine as recited in claim 34, further comprising a charge-air cooler (27) disposed between said low-pressure turbo (22) and high-pressure turbo (18). 36. The piston engine as recited in claim 22, wherein the air and fuel supply to said combustion chamber is adjusted to provide an equivalent air excess factor (λ) within the range 1.7-2.05 at an engine load within the range 18-30 bar BMEP. 37. The piston engine as recited in claim 22, wherein said injection device (56) is configured to initiate the fuel supply within the range 0 to 10 crank angle degrees before upper dead center. 38. The piston engine as recited in claim 22, wherein the injection device (56) is configured to provide a maximum injection pressure greater than 1600 bar. 39. The piston engine as recited in claim 22, wherein the injection device (56) is configured to provide a ratio between the needle opening pressure NOP and the maximum injection pressure maxIP greater than 0.7. 40. The piston engine as recited in claim 22, further comprising an at least partially heat-insulated exhaust duct that is connected to an exhaust port fitted to said combustion chamber. 41. The piston engine as recited in claim 22, wherein the air and fuel supply to said combustion chamber is adjusted to allow a maximum cylinder pressure during combustion greater than 8*BMEP. 42. The piston engine as recited in claim 41, wherein the air and fuel supply to said combustion chamber is adjusted to allow a maximum cylinder pressure during combustion greater than 9*BMEP. 43. The piston engine as recited in claim 42, wherein the air and fuel supply to said combustion chamber is adjusted to allow a maximum cylinder pressure during combustion greater than 10*BMEP.