INTERNAL COMBUSTION ENGINE

Abstract

Internal combustion engine (10) with: at least one turbocharger which has a compressor (1) and an exhaust turbine (2), and which can be stably operated in a stable operating range of a compressor map of the at least one compressor (1), which stable operating range is limited by a surge line (P) on the one hand, and by a choke line (S) on the other hand at least one actuator for setting an operating point (4) of the at least one compressor (1) in the compressor map a measuring device (5) for measuring at least two operating parameters of the turbocharger, by means of which a position of an operating point (4) of the at least one compressor (1) is determinable in the compressor map a closed loop or open loop control device (6) which is connected to the measuring device (5), and is designed to activate the at least one actuator
whereby the closed loop or open loop control device (6) is designed in a way to regulate or control the at least one actuator in such a way that reaching the surge line (P) by the operating point (4) of the at least one compressor (1) is prevented.

Claims

1. An internal combustion engine with: at least one turbocharger which has a compressor and an exhaust turbine, and which can be stably operated in a stable operating range of a compressor map of the at least one compressor, which stable operating range is limited by a surge line on the one hand, and by a choke line on the other hand at least one actuator for setting an operating point of the at least one compressor in the compressor map a measuring device for measuring at least two operating parameters of the turbocharger, by means of which a position of an operating point of the at least one compressor is determinable in the compressor map a closed loop or open loop control device which is connected to the measuring device, and is designed to activate the at least one actuator wherein the closed loop or open loop control device is designed in a way to regulate or control the at least one actuator in such a way that reaching the surge line by the operating point of the at least one compressor is prevented.

2. The internal combustion engine according to claim 1, wherein the at least two operating parameters of the turbocharger are selected from: pressure ratio across the compressor volume flow or mass flow through the compressor rotational speed of the turbocharger or parameters derived from these parameters.

3. The internal combustion engine according to claim 1, wherein the at least one actuator is designed as a bypass valve, wastegate, variable valve train, throttle valve, inlet valve for air or mixture downstream of the compressor, as variable turbine geometry, actuator for influencing the point of time of the ignition or for the shutdown of ignition devices for the combustion chambers, or as an actuator for influencing the quantity or point of time of injecting liquid or gaseous fuel in the combustion chambers.

4. The internal combustion engine according to claim 1, wherein the closed loop or open loop control device is designed so as to prevent reaching the surge line by the operating point when the operating point moves caused by external influences.

5. The internal combustion engine according to claim 4, wherein a signalling device is provided, which is connected to or connectable to an energy supply net, and is designed to transmit a signal to the closed loop or open loop control device when a net fault of the energy supply net is detected, wherein the closed loop or open loop control device is designed, upon receiving such a signal, to activate the at least one actuator in such a way that reaching the surge line by the operating point caused by measures of the closed loop or open loop control device, which serve to handle the net fault, is prevented.

6. The internal combustion engine according to claim 1, wherein the closed loop or open loop control device is designed to prevent the surge line from being reached by the operating point when the operating point moves caused by an internal influence.

7. The internal combustion engine according to claim 1, wherein the closed loop or open loop control device is designed to prevent the surge line from being reached by the operating point when the operating point moves caused by ageing of the compressor.

8. The internal combustion engine according to claim 1, wherein the closed loop or open loop control device is designed to cause the operating point to move along a predetermined path in the compressor map via the at least one actuator.

9. The internal combustion engine according to claim 8, wherein the closed loop or open loop control device is designed to cause the operating point to move along a predetermined path in the compressor map at least approximately parallel to the surge line via the at least one actuator.

10. The internal combustion engine according to claim 8, wherein the closed loop or open loop control device is designed to cause the operating point to move along a predetermined path within a corridor, which, preferably over a safety zone, is located in front of the surge line via the at least one actuator.

11. The internal combustion engine according to claim 1, wherein the closed loop or open loop control device is designed to calculate the activation of the at least one actuator in dependence on a compressor model.

12. The internal combustion engine according to claim 1, wherein the closed loop or open loop control device is designed to activate the at least one actuator in dependence on a pre-defined table.

13. Genset comprising a generator and an internal combustion engine mechanically coupled to the generator according to claim 1.

Description

[0039] Embodiments of the invention are discussed using the figures. They show:

[0040] FIG. 1 a schematic illustration of an internal combustion engine according to the invention

[0041] FIG. 2 a compressor map of a turbocharger of an internal combustion engine according to the invention.

[0042] FIG. 1 shows an internal combustion engine 10 with a plurality 15 of combustion chambers (if necessary connected with pre-chambers) shown only schematically, with not shown fuel supply facilities to the individual combustion chambers (e.g. inlet valves or active gas valves, port injection valves, injectors for liquid fuel, etc.), a turbocharger, which has a compressor 1 and an exhaust turbine 2, etc. An inlet tract 16 and an outlet tract 17 for air or a fuel-air mixture are shown.

[0043] Actuators for setting an operating point 4 of the turbochargers in the compressor map are shown examplatory, namely a throttle valve 12, a bypass valve 13, an inlet valve 14, and a wastegate 3. Further actuators can be provided with respect to the plurality 15 of combustion chambers (e.g. actuators for influencing the point of time of ignition or for shutdown of ignition devices for the combustion chambers, actuators for influencing the quantity or point of time of injecting liquid or gaseous fuel into the combustion chambers).

[0044] A measuring device 5 is provided for measuring at least two operating parameters of the turbocharger (here: pressure ratio across compressor 1, volume flow or mass flow through compressor 1 or rotational speed of the turbocharger) by means of which a position of an operating point 4 of the turbocharger in the compressor map is determinable.

[0045] A closed loop or open loop control device 6 is connected to the measuring device 5 (the connections are not shown), and designed to activate the actuators 3. The closed loop or open loop control device 6 is designed here as the central closed loop or open loop control unit for the entire internal combustion engine 10, and can also receive measured data from the plurality 15 of combustion chambers (including the assigned components such as active gas valves, pressure in supply lines, etc.), as well as issue commands to the plurality 15 of combustion chambers or the assigned components, respectively.

[0046] For generating power, the internal combustion engine 10 is mechanically connected (via a shaft) to a generator 9 to form a genset, and is electrically connected to a three-phase power supply net 8. A signalling device 7 is provided, which is connected or connectable to the power supply net 8, and is designed to transmit a signal to the closed loop or open loop control device 6 upon detection of a net fault of the power supply net 8, whereby the closed loop or open loop control device 6 is designed to activate the at least one actuator upon receiving such a signal in such a way that reaching the surge limit by the operating point is prevented which could be caused by means of measures (see the explanations to FIG. 2), which serve the handling of the net fault, in particular with respect to the LVRT (in general: reduction of the output of the internal combustion engine, e.g. suspension of ignition or setting of ignition to late).

[0047] FIG. 2 shows a compressor map of compressor 1 of the turbocharger (ordinate: pressure ratio over compressor 1, abscissa: temperature- and pressure-compensated mass flow {dot over (m)}.sub.red, whereby it can be seen that compressor 1 can be operated stably in a stable operating range, which stable operating range is limited by a surge line P on the one hand, and by a choke line S on the other hand. The dotted lines show isoreduced rotational speed lines (i.e. rotational speeds of the turbocharger compensated by the input temperature). Other than shown, the ordinate can also be plotted with the temperature-and pressure-compensated volume flow.

[0048] The operating point 4 is plotted in a position which is given in stable operation before a net fault occurs. Not shown are minor movements of the operating point 4 around the stable position, which can also occur during stable operation of the turbocharger.

[0049] If the signalling device 7 detects a net fault of the power supply net 8, it reports this to the closed loop or open loop control device 6. The closed loop or open loop control device 6 is designed to regulate or control the actuators in such a way as to prevent the surge line P being reached by the operating point 4 of compressor 1 of the at least one turbocharger despite the measures taken by the closed loop or open loop control device 6 for handling the net fault), and in particular with respect to the LVRT.

[0050] If the operating point 4 reaches corridor B, the closed loop or open loop control device 6, via the actuators, causes the operating point 4 to move along a specified path within corridor B, which over a safety area A is located in front of the surge line P. Corridor B, and thus the path, run at least approximately parallel to the surge line P. When the net fault has ceased, operating point 4 returns to its original position in the compressor map.

[0051] Safety zone A is selected in such a way that, on the one hand, a safe distance from the surge line P is maintained, and at the same time, on the other hand, not more boost pressure than necessary is reduced, so that sufficient boost pressure is available again after the net fault.

[0052] If the net fault lasts too long (e.g. if the so-called clearing time is exceeded), the connection between the genset and the power supply net 8 can be disconnected by a net switch 11.

LIST OF REFERENCE SIGNS

[0053] 1 compressor of the turbocharger [0054] 2 exhaust turbine of the turbocharger [0055] 3 wastegate [0056] 4 operating point of the turbocharger in the compressor [0057] 5 measuring device for measuring at least two operating parameters of the turbocharger [0058] 6 closed loop or open loop control device [0059] 7 signalling device connected to the power supply net [0060] 8 power supply net [0061] 9 generator [0062] 10 internal combustion engine [0063] 11 power switch [0064] 12 throttle valve [0065] 13 bypass valve [0066] 14 inlet valve [0067] 15 plurality of combustion chambers [0068] 16 inlet tract [0069] 17 exhaust tract