MOTEUR A COMBUSTION INTERNE

INTERNAL COMBUSTION ENGINE

Abrégé français

Un moteur à combustion interne (10) avec : au moins un turbocompresseur qui comprend un compresseur (1) et une turbine déchappement (2) et qui peut fonctionner de façon stable dans une plage de fonctionnement stable dune carte de compresseur des compresseurs, la plage de fonctionnement stable étant limitée dun côté par une limite de pompage (P) et de lautre côté par une limite de rendement (S); au moins un actionneur servant à établir un point de fonctionnement (4) des compresseurs (1) dans la carte compresseur; un appareil de mesure (5) servant à mesurer au moins deux paramètres de fonctionnement du turbocompresseur grâce auxquels il est possible de déterminer la position dun point de fonctionnement (4) des compresseurs (1) dans la carte compresseur; un appareil de commande en boucle ouverte ou en boucle fermée (6) connecté à lappareil de mesure (5) et conçu pour réguler ou contrôler les actionneurs de manière à prévenir latteinte de la limite de pompage (P) ou de la limite de rendement (S) par le point de fonctionnement (4) des compresseurs.

Abrégé anglais

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.

Revendications

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WHAT IS CLAIMED IS:
1. A system, comprising:
at least one turbocharger configured to couple to an internal combustion
engine,
wherein the at least one turbocharger comprises a compressor and an exhaust
turbine, and
the compressor is configured to provide a boost pressure and operate stably in
a stable
operating range between a surge line and a choke line of a compressor map;
at least one actuator configured to adjust an operating point of the
compressor
in the compressor map;
at least one sensor configured to measure one or more operating parameters of
the turbocharger to enable a determination of a position of the operating
point of the
compressor in the compressor map;
a transmitter configured to transmit a signal in response to detection of a
network
fault of an energy supply network; and
a controller connected to the at least one sensor, wherein the controller, in
response to the signal from the transmitter, is configured to control the at
least one actuator
to prevent the operating point from reaching the surge line as the operating
point moves in
the compressor map due to one or more measures taken by the controller to
handle the
network fault, wherein the controller is configured to control the at least
one actuator to
cause the operating point to move along a predetermined path within a corridor
along a
safety zone in the compressor map, wherein the safety zone extends along the
surge line,
and the safety zone is selected to provide a distance between the surge line
and the corridor
that minimizes a reduction of the boost pressure such that a sufficient boost
pressure is
available after the network fault.
2. The system according to claim 1, wherein the one or more operating
parameters of the turbocharger are selected from:
a pressure ratio across the compressor;
a volume flow or a mass flow through the compressor; or
a rotational speed of the turbocharger.
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283642-3
3. The system according to claim 1, wherein the at least one actuator
comprises at least one of: a bypass valve of the compressor, a wastegate of
the exhaust
turbine, a variable valve train, a throttle valve, an inlet valve configured
to adjust a supply
of air or a mixture downstream of the compressor, a variable turbine geometry,
an ignition
actuator configured to adjust an ignition time or a shutdown of ignition
devices for
combustion chambers of the internal combustion engine, or a fuel injection
actuator
configured to adjust a quantity or a point of time of injecting liquid or
gaseous fuel in the
combustion chambers.
4. The system according to claim 1, comprising the internal combustion
engine, wherein the exhaust turbine is disposed along an outlet tract of the
internal
combustion engine, and the compressor is disposed along an inlet tract of the
internal
combustion engine.
5. The system according to claim 4, comprising a generator driven by the
internal combustion engine, wherein the generator is configured to provide
energy to the
energy supply network.
6. The system according to claim 1, wherein the controller is configured to
control the at least one actuator to prevent the operating point from reaching
the surge line
when the operating point moves caused by a misfire with respect to at least
one combustion
chamber of the internal combustion engine.
7. The system according to claim 1, wherein the controller is configured to
control the at least one actuator to prevent the operating point from reaching
the surge line
when the operating point moves in the compressor map caused by aging of the
compressor.
8. The system according to claim 1, wherein the safety zone is parallel to
the surge line, and the corridor is parallel to the surge line.
9. The system according to claim 1, wherein the predetermined path is at
least approximately parallel to the surge line in the compressor map.
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11
10. The system according to claim 1, wherein the controller is configured
to
perform :
a first control comprising the one or more measures to handle the network
fault;
and
a second control of the at least one actuator to prevent the operating point
from
reaching the surge line as the operating point moves toward the surge line in
the compressor
map due to the first control comprising the one or more measures taken by the
controller
to handle the network fault.
11. The system according to claim 1, wherein the controller is configured
to
calculate an activation of the at least one actuator in dependence on a
compressor model.
12. The system according to claim 1, wherein the controller is configured
to
activate the at least one actuator in dependence on a pre-defined table.
13. The system according to claim 1, wherein the controller is configured
to
control the at least one actuator to prevent the operating point from reaching
the surge line
when the operating point moves caused by damage at the turbocharger.
14. The system according to claim 1, wherein the one or more measures taken
by the controller to handle the network fault comprise at least one of:
reducing an output
of the internal combustion engine, suspending an ignition of the internal
combustion
engine, or setting the ignition to late.
15. A system, comprising:
a controller configured to control operation of an internal combustion engine
having a turbocharger with a compressor and an exhaust turbine, wherein the
compressor
is configured to provide a boost pressure and operate stably in a stable
operating range
between a surge line and a choke line of a compressor map;
wherein the controller is configured to:
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12
receive sensor feedback indicative of one or more operating parameters
of the turbocharger to enable a determination of a position of an operating
point of the
compressor in the compressor map;
receive a signal indicative of a network fault of an energy supply
network; and
control at least one actuator to adjust the operating point of the
compressor in the compressor map in response to the signal, wherein the
control prevents
the operating point from reaching the surge line as the operating point moves
in the
compressor map due to one or more measures taken by the controller to handle
the network
fault, wherein the controller is configured to control the at least one
actuator to cause the
operating point to move along a predetermined path within a corridor along a
safety zone
in the compressor map, wherein the safety zone extends along the surge line,
and the safety
zone is selected to provide a distance between the surge line and the corridor
that minimizes
a reduction of the boost pressure such that a sufficient boost pressure is
available after the
network fault.
16. The system according to claim 15, comprising the turbocharger having
the compressor and the exhaust turbine.
17. The system according to claim 16, comprising the internal combustion
engine having the turbocharger.
18. The system according to claim 15, comprising one or more sensors
configured to obtain the sensor feedback and a transmitter configured to
transmit the signal
to the controller.
19. The system according to claim 15, wherein:
the one or more measures taken by the controller to handle the network fault
comprise at least one of: reducing an output of the internal combustion
engine, suspending
an ignition of the internal combustion engine, or setting the ignition to
late; and
the at least one actuator comprises at least one of: a bypass valve of the
compressor, a wastegate of the exhaust turbine, a variable valve train, a
throttle valve, an
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inlet valve configured to adjust a supply of air or a mixture downstream of
the compressor,
a variable turbine geometry, an ignition actuator configured to adjust an
ignition time or a
shutdown of ignition devices for combustion chambers of the internal
combustion engine,
or a fuel injection actuator configured to adjust a quantity or a point of
time of injecting
liquid or gaseous fuel in the combustion chambers.
20. A method, comprising:
controlling, via a controller, operation of an internal combustion engine
having
a turbocharger with a compressor and an exhaust turbine, wherein the
compressor is
configured to provide a boost pressure and operate stably in a stable
operating range
between a surge line and a choke line of a compressor map;
wherein controlling the operation comprises:
receiving sensor feedback indicative of one or more operating parameters
of the turbocharger to enable a determination of a position of an operating
point of the
compressor in the compressor map;
receiving a signal indicative of a network fault of an energy supply
network; and
controlling at least one actuator to adjust the operating point of the
compressor in the compressor map in response to the signal, wherein
controlling the at least
one actuator comprises preventing the operating point from reaching the surge
line as the
operating point moves in the compressor map due to one or more measures taken
by the
controller to handle the network fault, wherein controlling the at least one
actuator
comprises causing the operating point to move along a predetermined path
within a corridor
along a safety zone in the compressor map, wherein the safety zone extends
along the surge
line, and the safety zone is selected to provide a distance between the surge
line and the
corridor that minimizes a reduction of the boost pressure such that a
sufficient boost
pressure is available after the network fault.
Date recue/Date Received 2021-02-03

Description

283642-3
1
INTERNAL COMBUSTION ENGINE
The present invention concerns an internal combustion engine with an internal
combustion engine, and a genset comprising such an internal combustion engine.
Turbochargers have long been used to compress air, a fuel-air mixture or pure
fuel to a
higher pressure level before being fed to the combustion chambers of the
internal
combustion engine.
The surge line of the compressor of the turbocharger indicates that limit at
which, in the
event of exceeding it, an unstable operation, e.g. a flow reversal, occurs
through the
compressor.
The choke line of the compressor of the turbocharger indicates that limit at
which there
is no mass flow through the compressor in case of reaching the limit.
External and internal influences can lead to the position of the operating
point of the
compressor changing, and even to the surge line being reached or exceeded.
Aging of
the turbocharger can also lead to such a behaviour.
If the internal combustion engine is coupled with a generator to a genset, an
important
example of an external influence is a net fault in a power supply net
connected to the
genset. This can be for example a short circuit in at least one phase of the
power
supply net. This leads to an undervoltage and an overcurrent, which causes
strong and
rapid load changes with respect to the genset. Various national legal systems
stipulate
that the genset must remain connected to the energy supply net at least for a
certain
time in the event of a net Glow voltage ride through" - LVRT). Without
protective
measures, there may be disadvantageous effects on the genset.
Examples of internal influences are a damage at the turbocharger, misfiring
with
respect to at least one combustion chamber of the internal combustion engine,
etc.
The object of the invention is to provide an internal combustion engine, which
allows,
even in case of influences, which, in the state of the art, cause the surge
line of the
Date Recue/Date Received 2020-07-21

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compressor to be reached or exceeded, a stable operation of the turbocharger,
and a
genset with such an internal combustion engine.
As the closed loop or open loop control device is designed to regulate or
control the at
least one actuator in such a way that reaching the surge line is prevented by
the
operating point of the at least one compressor, stable operation of the
turbocharger is
possible even in case of negative external or internal influences.
The closed loop or open loop control device may, for example, be a central
closed loop
or open loop control device of the internal combustion engine.
Naturally, the possible positions of the operating point in the compressor map
are
limited by the maximum mechanical limits of the turbocharger.
It is preferably provided that the at least two operating parameters of the
turbocharger,
which are measured by the measuring device, are selected as follows:
- pressure ratio across the compressor
- volume flow or mass flow through the compressor
- rotation speed of the turbocharger
or parameters derived from these parameters.
It is preferably provided that at least one actuator is designed as a bypass
valve,
wastegate, variable valve train, throttle valve, inlet valve for air or a
mixture after the
compressor, as a variable turbine geometry, as an actuator for influencing the
point of
time of 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 into the combustion chambers.
It is preferably provided that the closed loop or open loop control device is
designed in
such a way that, if the operating point moves caused by external influences,
reaching
the surge line by the operating point is prevented.
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=
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For this, a signalling device may be provided, which is connectable to a power
supply
net, and is designed to send a signal to the closed loop or open loop control
device
when a net fault of the power supply net is detected, whereby the closed loop
or open
loop control device is designed in such a way that, when such a signal is
received, an
activation of the at least one actuator is to be carried out as to prevent the
operating
point from reaching the surge line due to measures taken by the closed loop or
open
loop control device which serve to handle the net fault (in general: reduction
of the
output of the internal combustion engine, e.g. suspension of ignition or
setting the
ignition to "late").
This bears a number of advantages:
- The probability of reaching or exceeding the surge line during the LVRT is
reduced.
- The negative effects of a net fault during an LVRT regarding the
turbocharger are
reduced.
- Longer durations of the LVRT are possible.
- During the LVRT there is a lower power loss of the internal
combustion engine as
the functionality of the turbocharger is less impaired.
- Generators with a lower moment of inertia than previously possible can be
used.
It is preferably provided that the closed loop or open loop control device is
designed to
prevent the surge line being reached by the operating point if the operating
point
moves caused by an internal influence (e.g. damage at the turbocharger,
misfire with
respect to at least one combustion chamber of the internal combustion engine).
It is preferably provided that the closed loop or open loop control device is
designed to
prevent the surge line being reached by the operating point if the operating
point
moves caused by ageing of the compressor.
It is preferably provided that 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.
It may thereby be provided that the closed loop or open loop control device is
designed
to cause the operating point to move along a predetermined path in the
compressor
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map at least approximately parallel to the surge line via the at least one
actuator. The
closer the operating point remains to the surge line, the lower is the drop in
output of
the turbocharger, and thus of the internal combustion engine, because the
boost
pressure of the air, the fuel-air mixture or the pure fuel (depending on the
design of the
.. internal combustion engine, e.g. gas engine with mixture charging, gas
engine with port
injection, internal combustion engine with injection of liquid fuel, dual-fuel
internal
combustion engine) drops less strongly.
It may be provided that the closed loop or open loop control device is
designed to
cause the operating point to move along a predetermined path within a corridor
arranged in front of the surge line, preferably over a safety zone, via at
least one
actuator.
It is preferably provided that 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. The way of calculation is taught, for example, in the following text
books:
- Hermann Hiereth, Peter Prenninger, Aufladung der
Verbrennungskraftmaschine ¨
Der Fahrzeugantrieb / chapter 5, 2003, published by Springer / Vienna
- Gunther P. Merker, Rudiger Teichmann, Grundlagen Verbrennungsmotoren
(Funktionsweise ¨ Simulation ¨ Messtechnik) / chapter 5 (Aufladesysteme), 7th,
completely revised edition, 2014, published by Springer/Vienna
- Gunther P. Merker, Christian Schwarz, Grundlagen Verbrennungsmotoren
(Simulation der Gemischbildung, Verbrennung, Schadstoffbildung und Aufladung)
/
chapter 8 (Aufladung von Verbrennungsmotoren) 4th, revised and updated edition
Vieweg + Teubner, GVVV Fachverlage GmbH, Wiesbaden 2009
It is preferably provided that the closed loop or open loop control device is
designed to
activate the at least one actuator depending on a pre-defined table. The table
can be
based on empirical values or created on a test stand.
The invention can preferably be used with a stationary internal combustion
engine, for
marine applications or mobile applications, such as so-called "non-road mobile
machinery" (NRMM), preferably in each case designed as a reciprocating piston
engine. The internal combustion engine can serve as a mechanical drive, e.g.
for
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operating compressor systems, or can be coupled with a generator to form a
genset for
generating electrical power. The internal combustion engine preferably has a
large
number of combustion chambers.
5 Embodiments of the invention are discussed using the figures. They show:
Fig. 1 a schematic illustration of an internal combustion engine according to
the
invention
Fig. 2 a compressor map of a turbocharger of an internal combustion engine
according to the invention.
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.
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).
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.
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
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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.
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").
Fig. 2 shows a compressor map of compressor 1 of the turbocharger (ordinate:
pressure ratio Tr over compressor 1, abscissa: temperature- and pressure-
compensated mass flow thred, 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.
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.
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
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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.
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.
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.
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.
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list of reference signs:
1 compressor of the turbocharger
2 exhaust turbine of the turbocharger
3 wastegate
4 operating point of the turbocharger in the compressor
5 measuring device for measuring at least two operating parameters of
the
turbocharger
to 6 closed loop or open loop control device
7 signalling device connected to the power supply net
8 power supply net
9 generator
internal combustion engine
11 power switch
12 throttle valve
13 bypass valve
14 inlet valve
15 plurality of combustion chambers
16 inlet tract
17 exhaust tract
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