EP3329111A1

EP3329111A1 - Power generating assembly, vehicle comprising a power generating assembly, and method for adjusting an inert gas pressure

Info

Publication number: EP3329111A1
Application number: EP16741231.1A
Authority: EP
Inventors: Manuel Boog; Wolfgang Fimml; Jan Gerrit Prunnbauer
Original assignee: MTU Friedrichshafen GmbH
Current assignee: Rolls Royce Solutions GmbH
Priority date: 2015-07-30
Filing date: 2016-07-07
Publication date: 2018-06-06
Also published as: WO2017016638A1; US20180223773A1; CN107850012A; HK1252902A1; CN107850012B; DE102015214563B3

Abstract

The invention relates to a power generating assembly (1) comprising an internal combustion engine (3) and a combustion gas supply (5) which is connected to the internal combustion engine (3) in order to supply combustion gas. The combustion gas supply (5) has an at least double-walled line (9) at least in the region of the internal combustion engine (3), said line having an inner line volume (11) for combustion gas and an outer line volume (13). The outer line volume (13) is fluidically connected to an inert gas supply (15). The power generating assembly also comprises a combustion gas pressure adjusting device (17), which is designed to adjust a combustion gas pressure in the inner line volume (11), and an inert gas pressure adjusting device (19), which is designed to adjust an inert gas pressure in the outer line volume (13). The combustion gas pressure adjusting device (17) and the inert gas pressure adjusting device (19) are designed to select the inert gas pressure and the combustion gas pressure such that the inert gas pressure is higher than the combustion gas pressure.

Description

MTU Friedrichshafen GmbH

DESCRIPTION

Power generating assembly, vehicle having a power generating assembly and method for adjusting an inert gas pressure

The invention relates to a power generation arrangement, a vehicle with a

Power generation arrangement and method for adjusting an inert gas pressure.

Classification conditions for marine applications of internal combustion engines, which are to be operated with fuel gas, typically provide measures for gas safety, which are intended in particular to prevent that in a machine room of a ship

explosive mixture of fuel gas and air forms. For this purpose, it is known to use double-walled fuel gas lines, wherein flows in an inner line volume of fuel gas, and wherein an outer line volume is purged with air or an inert gas. Such double-walled lines are in need of improvement in terms of their leakage safety.

The invention has for its object to provide a power generation arrangement, a vehicle with such a power arrangement and a method for adjusting an inert gas pressure, said disadvantages do not occur.

The object is achieved by providing the subject matters of the independent claims. Advantageous embodiments emerge from the subclaims.

The object is achieved in particular by providing a power generation arrangement comprising an internal combustion engine and a fuel gas supply connected to the internal combustion engine for supplying fuel gas. The fuel gas supply has, at least in the region of the internal combustion engine, an at least double-walled line, which has an inner line volume for fuel gas and an outer line volume, wherein the outer line volume is fluidly connected to an inert gas supply. It is one

Fuel gas pressure adjusting device provided which is adapted to set a

Fuel gas pressure in the inner pipe volume. Furthermore, one is

Inertgasdruckstelleinrichtung provided which is adapted to set a Inert gas pressure in the outer pipe volume. By adjusting the inert gas pressure in the line volume, the leakage safety of the at least double-walled line is significantly increased, since defined pressure conditions can be provided here. Advantageously, it is provided that the fuel gas pressure adjusting device and the inert gas pressure adjusting device are arranged to select the inert gas pressure and the fuel gas pressure so that the

Inert gas pressure in the outer pipe volume is higher than the fuel gas pressure in the inner pipe volume. In particular, in this way, the gas tightness and leakage safety of the fuel gas supply in the region of at least double-walled line is significantly increased, especially as a leak in a line volumes separating the inner wall does not lead to leakage of fuel gas in the outer pipe volume, but rather to an influx of inert gas in the inner pipe volume. Thus, in such a fault, no flammable or explosive mixture arise, but in a larger leakage, the internal combustion engine is stifled by the inert gas, so that a safe operating condition is achieved.

The fact that the fuel gas supply has an at least double-walled line, at least in the region of the internal combustion engine, means, in particular, that the double walledness of the line is provided in the immediate vicinity of the internal combustion engine, in particular in a closed space in which the internal combustion engine is arranged. Preferably, the internal combustion engine is arranged in a machine room, in which the fuel gas supply has an at least double-walled line. The arrangement of the internal combustion engine in a separate, closed engine room and at the same time the provision of an at least double-walled line to the fuel gas supply of the internal combustion engine allows according to today's classification standard in particular an arrangement of a plurality of

Internal combustion engines in one and the same engine room.

It is preferably provided that the fuel gas pressure adjusting device outside of

Engine room is arranged in a separate printing room. This increases the

Gas safety of the power generation arrangement on, because by this separation of the fuel gas pressure adjusting device of the engine room for the

Brenngasdruckstelleinrichtung quasi - on the wall of Druckstellraums - a

Doppelwandigkeit can be realized. This is not possible in other ways, because valves required for the fuel gas pressure adjusting device are not in double-walled

Execution are available. Preferably, the Inertgasdruckstelleinrichtung is arranged in the pressure chamber. The fact that the line is designed to be at least double-walled means, in particular, that the line has at least two lines arranged nested one inside the other, thus an inner line and an outer line surrounding the inner line. It is possible that the line has more than two nested lines.

Here, an inner conduit volume is understood to mean an interior of the inner conduit of the at least double-walled conduit, wherein the inner conduit volume of a

Inner wall is enclosed, and wherein flows in the inner pipe volume during operation of the power generation assembly fuel gas. An outer conduit volume is understood to mean an interior of an outer conduit of the at least double-walled conduit, which is delimited outwardly by an outer wall and inwardly by the inner wall. The outer pipe volume thus surrounds the inner pipe volume. In the outer line volume is located in the operation of the power generation arrangement inert gas.

An inert gas is understood in particular to mean a gas which does not form an ignitable or combustible mixture, in particular an explosive mixture, with the fuel gas, regardless of a mixing ratio. The inert gas is thus chosen in particular so that it is at least among the ruling in the operation of the power generation arrangement with the fuel gas

Conditions can not react. Nitrogen is particularly preferably used as the inert gas, but other inert gases such as, for example, carbon dioxide or noble gases,

For example, argon, possible. Gas mixtures can also be used as inert gas. A fuel gas is understood in particular to mean a gaseous substance or a gaseous substance mixture under normal conditions, in particular at 1013 mbar absolute and 25 ° C., which is suitable as fuel for operating an internal combustion engine. Particular preference is given to using a methane-containing fuel gas, in particular natural gas. The fuel gas pressure adjusting device is preferably designed to control or regulate the fuel gas pressure, wherein an adjustment of the fuel gas pressure is understood in particular to mean a control or regulation of the fuel gas pressure. Particularly preferred is the

Brenngasdruckstelleinrichtung designed as a gas control and regulating the

Fuel gas pressure set up. The inert gas pressure adjusting device is preferably configured to control or regulate the inert gas pressure, wherein in this case as well under an adjustment of the inert gas pressure

in particular a control or a regulation, particularly preferably a regulation is understood.

For the fuel gas pressure adjusting device, a lower pressure setpoint is preferably set than for the inert gas pressure adjusting device, so that the inert gas pressure in the outer piping volume is higher than the fuel gas pressure in the piping volume.

According to an embodiment of the power generation arrangement, it is provided that the inert gas supply has a feed container which is fluid-connected to the outer line volume via a first switching valve. Under a food container is understood in particular a container whose volume is known and smaller than the volume of the outer pipe volume. Preferably, the volume of the food container is a factor of at least 10 to at most 40, preferably at least 20 to at most 30,

preferably smaller by a factor of 25 than the volume of the outer conduit volume. For example, it is possible for the outer conduit volume to have a volume of 10 L, with the volume of the food container preferably being 0.5 L. The feed container serves in particular as a buffer container in order to provide inert gas for maintaining the inert gas pressure in the event of a leakage, and in order to be able to easily determine a leakage rate, in particular due to the known and small volume. The Inertgasdruckstelleinrichtung is preferably operatively connected to the first switching valve to its control. The first switching valve is particularly clocked preferably controlled, in particular clocked open- and closable, so that the outer line volume clocked via the first switching valve inert gas feed from the feed container or can be discharged into the food container. The first switching valve is preferably digitally switchable in exactly two functional positions, namely in one

Open position and in a closed position. In this way, the first switching valve is simple, inexpensive and easily controlled.

According to one embodiment of the invention, it is provided that the inert gas supply has an inert gas reservoir, wherein the food container is fluid-connected to the inert gas reservoir via a second switching valve. Alternatively or additionally, it is provided that the

Inert gas supply has an inert gas generating device, wherein the food container with the inert gas generating means is fluidly connected via the second switching valve. The second switching valve is preferably operatively connected to the Inertgasdruckstelleinrichtung to its control, wherein it can be controlled in particular clocked, in particular openable and closable. The second switching valve is preferably digitally switchable in exactly two functional positions, namely in an open position and a closed position. It can therefore be simple and inexpensive and easy to control. An inert gas reservoir is to be understood here in particular as a storage container, in particular an inert gas tank, wherein the inert gas tank may preferably be designed as a bottle storage. A large amount of inert gas, which is sufficient in particular for a longer stay at sea, can preferably be stored in the inert gas reservoir. The food container can preferably be fed clocked by driving the second switching valve from the Inertgasreservoir.

Preferably, the volume of the food container is much smaller than the volume of the

Inertgasreservoirs. Moreover, it is possible and preferably provided that the volume of the food container is known in more detail than the volume of the inert gas reservoir.

An intergas production device is understood to mean a device that is set up to recover inert gas. This may be, for example, a nitrogen generator which can extract nitrogen from ambient air. It is then preferably possible for the food container - in particular clocked - on the second switching valve from the

Inert gas generating device to feed.

It is also possible that the inert gas supply has both an inert gas reservoir and an inert gas generating device, in which case preferably the inert gas reservoir can be fed from the inert gas generating device, the feed reservoir preferably being fed from the inert gas reservoir.

The first switching valve and the second switching valve are - viewed from the outer line volume - preferably connected in series, that is arranged fluidly one behind the other. In this case, the first switching valve and the second switching valve are preferably switched alternately by the inert gas pressure setting device, in particular open alternately. The food container is thus in particular alternately with the outer line volume on the one hand and the

Inertgasreservoir and / or the inert gas generating device on the other fluidly connected. In this way, defined amounts of inert gas can be removed from the food container on the one hand and on the other hand fed to this. It is then possible, in particular in a simple and cost-effective manner, to calculate a leakage rate via the switching cycles or the switching frequency of the switching valves on the one hand and the pressure level in the outer line volume on the other hand. An otherwise necessary additional, additional volumetric flow meter can then be omitted, so that the costs associated therewith and the weight associated therewith are saved. This advantage results in particular from the fact that due to the small volume of

When opening a switching valve always immediately adjusts a pressure equilibrium with the volume beyond the switching valve, ie in particular the outer line volume or the inert gas and / or the Inertgaserzeugungseinrichtung, this pressure is close to a pressure value before opening the switching valve in the - of the

Food container seen from - beyond the switching valve arranged volume prevailed.

At the same time it follows that for a pressure build-up and / or pressure reduction in the outer conduit volume always a plurality of opening cycles of the first and second switching valve is necessary because the volume of the feed container is not sufficient to the pressure there after a pressure drop in the outer line volume to be brought to a desired value by opening the first switching valve once. Rather, it requires a cyclic feeding of the outer line volume from the food container and a subsequent filling of the feed tank from the inert gas reservoir and / or the inert gas generating device - or vice versa. Here are based on simple thermodynamic relationships always readily the mass and / or flow rates in the individual switching cycles in the

Food container and out of the food container out, in particular, in combination with the switching cycles of the switching valves, in particular with the switching frequency, with which the switching valves are controlled, and these volume or mass flows, a leakage rate can be calculated from the outer line volume.

According to one embodiment of the invention it is provided that the food container is fluidly connected via a third switching valve with an inert gas vent. The third switching valve is preferably operatively connected to the Inertgasdruckstelleinrichtung to its control, wherein it can be controlled in particular clocked, in particular clocked open and closed. The third switching valve is preferably digitally switchable in exactly two functional positions, namely in an open position and in a closed position. It can therefore be simple and inexpensive and easy to control. The supply container can be relieved by the third switching valve clocked to the inert gas vent out. The third switching valve is - by the outer line volume seen from - in particular in series with the first switching valve and connected in parallel to the second switching valve.

By clocked, in particular alternating driving of the first switching valve, the second switching valve and / or the third switching valve, it is now possible in a very simple manner to regulate the inert gas pressure in the outer conduit volume by - to increase the pressure - the outer conduit volume by opening of the first switching valve at the same time

Inert gas is supplied from the feed container closed second and third switching valves, wherein then with open second switching valve and closed first and third switching valves the feed container from the inert gas reservoir and / or the

Inert gas generating means again inert gas is supplied, wherein - to reduce the pressure - by opening the third switching valve with simultaneously closed first and second switching valves inert gas and pressure can be discharged from the feed tank via the inert gas vent, in which case with open first switching valve and

Inert gas can be removed from the outer line volume and transferred to the food container. Depending on the actual pressure level, it is also possible to first overpressure from the outside

To relieve line volume in the food container, and then vent the feed tank to the inert gas vent.

Inert gas venting is understood in particular to mean a device by means of which inert gas can be discharged to an environment of the power generation system.

In particular, in a marine application of the power generation arrangement is the

Inertgasentlüftung preferably in a so-called Ventmast, that is one

Venting chimney of a ship, integrated.

According to one development of the invention, it is provided that a pressure sensor for detecting an inert gas pressure is arranged in or on the outer line volume, the pressure sensor being operatively connected to the inert gas pressure setting device. In this way, an actual pressure in the outer line volume can always be determined, so that a regulation of the inert gas pressure in the outer line volume can be carried out on the basis of an actual nominal pressure deviation. In addition, the pressure level of the inert gas in the outer conduit volume detected by the pressure sensor is preferably used together with the switching cycles or the switching frequency of the switching valves in order to determine a leakage rate. According to one embodiment of the invention, it is provided that the inert gas pressure adjusting device is set up for adjusting the inert gas pressure in the outer line volume by cyclically actuating the first switching valve on the one hand and the second switching valve or the third switching valve on the other. As already described above, in this way the pressure in the outer line volume can be increased and / or decreased, in particular regulated.

According to one embodiment of the invention, it is provided that the inert gas pressure adjusting device is set up to control at least two switching valves with a switching frequency which depends on a pressure variable of the inert gas pressure in the outer line volume. The switching frequency can then be selected advantageously depending on the actual conditions present in the outer line volume, wherein, for example, a slower switching frequency can be selected with only a slow decrease or increase in pressure, with a greater or faster decrease or increase in pressure, a higher switching frequency can be chosen, in this way can be reacted flexibly to a rapid pressure increase or leakage in the outer pipe volume.

A pressure variable is understood in particular to mean a physical quantity which is related to or depends on the inert gas pressure in the outer conduit volume. In particular, the inert gas pressure in the outer conduit volume itself can be used as the pressure variable. It is also possible that a time derivative of the inert gas pressure is used as the pressure variable. Alternatively or additionally, it is also possible that the

Inert gas pressure over a predetermined period of time is integrated, wherein the integral is used as a pressure variable. It is also possible for a plurality of pressure variables, in particular the inert gas pressure itself, a time derivative of the inert gas pressure and / or an integral of the inert gas pressure to be used for determining the switching frequency. This depends, in particular, on the configuration of the inert-gas pressure-regulating device as a pressure regulator, namely in particular on whether the inert-gas pressure-regulating device is used as a proportional controller (P controller), as a proportional-derivative controller (PD controller), as a proportional-integral controller (PI controller). , is designed as a proportional-integral-derivative (PID) controller, or in some other suitable way. The switching frequency of the switching valves preferably represents a manipulated variable for the pressure control in the outer line volume. According to one development of the invention, it is provided that the inert gas pressure adjusting device is set up to determine a leakage rate from the outer line volume on the basis of a momentary switching frequency of the switching valves and a pressure variable of the inert gas pressure in the outer line volume. In particular, when the instantaneous switching frequency represents a manipulated variable for the pressure control and / or is selected as a function of the pressure variable of the inert gas pressure, this is dependent on a pressure loss rate, thus a leakage rate from the outer line volume. Is this in addition

Pressure level in the outer line volume known in the form of the pressure variable can - especially due to the fact that the volume of the feed container is precisely known and small - readily the leakage rate of the switching frequency on the one hand and the

Print size, on the other hand be calculated.

The inert gas pressure adjusting device is preferably designed to generate at least one alarm signal depending on the specific leakage rate, wherein in particular a first threshold value is provided for a first alarm signal. In addition, a second, higher threshold value for a second alarm signal is preferably provided, wherein the alarm signals are output when the threshold values of the leakage rate associated therewith

be crossed, be exceeded, be passed. Under an alarm signal here is a message to an operator of

Power generation arrangement understood, wherein the alarm signal may be in particular an optical signal, an acoustic signal, a vibration signal, an electrical signal or other suitable signal. For example, different alarm signals corresponding to different leakage rates may be of different colors or different

Alarm signal intensities be connected. For example, if a first threshold value for the leakage rate is exceeded, it is possible for a yellow light to light up in order to indicate that a leak has occurred that is still tolerable and does not require any immediate measures. When the second, higher threshold value for the leakage rate is exceeded, a red light is preferably activated, which indicates that there is a leakage of the outer line volume which, although still presently tolerable, can still be tolerated

Necessary measures to remedy and in particular to prevent further enlargement of the leakage. It is preferably provided that the inert gas pressure adjusting device is set up to stop the internal combustion engine if a third threshold value for the leakage rate

is exceeded, which represents a no longer tolerable leakage, in particular, a risk of fire or explosion may exist. This third threshold is preferably higher than the second threshold and / or higher than the first threshold. Preferably, a third alarm signal is generated at the same time, which the operator of the

Power generation arrangement signals the leakage on the one hand and the stop of the engine on the other. The internal combustion engine is preferably designed as a reciprocating engine. It is possible that the internal combustion engine is arranged to drive a passenger car, a truck or a commercial vehicle. In a preferred embodiment, the internal combustion engine is the drive in particular heavy land or water vehicles, such as mine vehicles, trains, the internal combustion engine in a

Locomotive or a railcar is used, or by ships. It is also possible to use the internal combustion engine to drive a defense vehicle, for example a tank. An exemplary embodiment of the internal combustion engine is preferably also stationary, for example, for stationary power supply in emergency operation,

Permanent load operation or peak load operation used, the internal combustion engine in this case preferably drives a generator. Also a stationary application of

Internal combustion engine for driving auxiliary equipment, such as fire pumps on oil rigs, is possible. Furthermore, an application of the internal combustion engine in the field of promoting fossil raw materials and in particular fuels, for example oil and / or gas, possible. It is also possible to use the internal combustion engine in the industrial sector or in the field of construction, for example in a construction or construction machine, for example in a crane or an excavator. The internal combustion engine is preferably designed as a diesel engine, as a gasoline engine, as a gas engine for operation with natural gas, biogas, special gas or another suitable gas. In particular, when the internal combustion engine is designed as a gas engine, it is suitable for use in a cogeneration plant for stationary power generation.

It is possible that the internal combustion engine has a plurality of cylinder banks, for example an A-bank and a B-bank. In this case, preferably everyone

Cylinder bank assigned its own, at least double-walled line, with everyone Cylinder bank is assigned its own, separate outer line volume. Each of these line volumes is preferably fluid-connected to the feed container via a separate first switching valve. Incidentally, the same applies to each outer line volume of a cylinder bank and to each first switching valve, which was previously generally carried out for an outer line volume and a first switching valve. Preferably, the food container, the second

Switching valve and preferably the third switching valve for all cylinder banks together and therefore provided only once.

The object is also solved by creating a vehicle which has a

Power generating arrangement according to one of the embodiments described above. The vehicle is particularly preferably designed as a ship. A particularly preferred embodiment of the vehicle is designed as a harbor tug. The power generation arrangement proposed here makes it possible in a particularly favorable manner to fulfill classification requirements for the safe operation of internal combustion engines with fuel gas on board a ship.

The vehicle preferably has a machine room in which at least one

Internal combustion engine of the power generation arrangement is arranged. The

Fuel gas pressure adjusting device and the Inertgasdruckstelleinrichtung are preferably arranged in a separate pressure chamber, which is divided from the engine room. The line of the fuel gas supply is preferably formed at least double-walled only in the engine room. The pressure chamber is preferably separated from a

Storage space in which a fuel gas reservoir is arranged. In the same storage space or in another storage space, an inert gas reservoir and / or an inert gas reservoir can / can be used

Inert gas generating means may be arranged.

The food container is preferably arranged in the pressure chamber.

The object is also achieved by a method for adjusting an inert gas pressure in an outer pipe volume of an at least partially double-walled

Fuel gas supply is provided, wherein the inert gas pressure in an outer

Line volume is selected higher than a fuel gas pressure in an inner pipe volume of the fuel gas supply. In this way, in particular those already in

Related to the power generation arrangement described advantages. Particularly preferably, the inert gas pressure and / or the fuel gas pressure is / are regulated, wherein a desired value for the inert gas pressure is preferably higher than a desired value for the inert gas pressure

Fuel gas pressure.

In the context of the method, the inert gas pressure in the outer conduit volume is preferably controlled by cyclically actuating a first switching valve, which is arranged in a first fluid connection between the outer conduit volume and a food container, on the one hand, and a second switching valve, which in a second fluid connection between the food container and an inert gas reservoir and / or an inert gas generating means is arranged, and / or a third switching valve, which is arranged in a third fluid connection between the feed container and an inert gas vent, on the other hand, set. Preferably, at least two switching valves selected from the first switching valve, the second switching valve, and the third switching valve are driven at a switching frequency selected depending on a pressure amount of the inert gas pressure in the outer pipe volume. Preferably, based on a current switching frequency and a current

Pressure value of the inert gas pressure in the outer pipe volume determines a leakage rate of inert gas from the outer pipe volume.

The description of the power generation arrangement and the vehicle on the one hand and the method on the other hand are to be understood complementary to each other. Features of

Power generation arrangement and the vehicle, which have been explicitly or implicitly explained in connection with the method are preferably individually or combined features of a preferred embodiment of the power generating arrangement or the vehicle. Procedural steps that are explicit or implicit in connection with the

Power generation arrangement and / or the vehicle have been explained, are preferably individually or combined steps of a preferred embodiment of the method.

This is preferably characterized by at least one method step, which is due to at least one feature of an inventive or preferred embodiment of the power generation arrangement or the vehicle. The Power generating arrangement and / or the vehicle preferably draws / distinguished by at least one feature, which is due to at least one step of an inventive or preferred embodiment of the method. The invention will be explained in more detail below with reference to the drawing. Showing:

Figure 1 is a schematic representation of an embodiment

Power generation arrangement, and

Figure 2 is a schematic representation of the operation of the

Power generation assembly.

1 shows a schematic representation of an exemplary embodiment of a vehicle 100 with a power generation arrangement 1, which has an internal combustion engine 3 and a fuel gas supply 5 connected to the internal combustion engine 3 for supplying fuel gas. The fuel gas supply 5 is double-walled, at least in the region of the internal combustion engine 3, in particular within an engine room 7, thus has a double-walled line 9, wherein the internal combustion engine 3 here two cylinder banks A, B, each cylinder bank having a separate double-walled line. 9 A, 9.B is assigned. The double-walled lines 9 each have an inner line volume 11 by 3 fuel gas flows during operation of the internal combustion engine, and an outer line volume 13, which surrounds the inner line volume 11, and in which at least during operation of the

Internal combustion engine 3, an inert gas is arranged. The outer conduit volume 11 is fluidly connected to an inert gas supply 15.

A fuel gas pressure device 17 is provided, which is set up to set a fuel gas pressure in the inner pipe volume 11, wherein the

Fuel gas pressure adjusting device is designed here in particular as a gas control path and is set up for a regulation of the fuel gas pressure in the inner line volume 11.

An inert gas pressure adjusting device 19 is provided, which is set up for setting, in particular for regulating, an inert gas pressure in the outer line volume 13. The fuel gas pressure adjusting device 17 and the inert gas pressure regulating device 19 are arranged here in a separate pressure chamber 21 separated from the engine room.

The fuel gas pressure adjusting device 17 and the inert gas pressure adjusting device 19 are configured to select the inert gas pressure and the fuel gas pressure so that the inert gas pressure in the outer piping volume 13 is higher than the fuel gas pressure in the inner piping volume 11.

The inert gas supply 19 has a food container 23 which is connected to the outer

Line volume 13 is fluidly connected via a first switching valve 25. Here is the

Cylinder banks A, B each have a first switching valve 25. A, 25. B assigned, wherein in the following only the operation of a first switching valve 25 in connection with a cylinder bank A, B will be described, with the operation for the other cylinder bank B, A completely analog results. It is possible that the internal combustion engine 3 has only one cylinder bank, in which case only one external volume 13 and only one first switching valve 25 are provided. However, the concept can be extended to any number of cylinder banks A, B by assigning a separate outer volume 13 to each cylinder bank and assigning each separate outer conduit volume 13 with its own first switching valve 25.

Everything which is generally carried out in the following by way of a first switching valve 25, applies here concretely for both first switching valves 25.A, 25B.

The inert gas supply 25 also has an inert gas reservoir 27 and here also an inert gas generating device 29. By means of the inert gas generating device 29, which is preferably designed as a nitrogen generator, inert gas can be generated, which can then be stored in the Inertgasreservoir 27. The food container 23 is here

in particular fluidly connected to the inert gas reservoir 27 via a second switching valve 31. Seen from the outer line volume 13, the first switching valve 25 and the second switching valve 31 are arranged in series. The food container 23 is arranged fluidly between the second switching valve 31 and the first switching valve 25. The feed container 23 is fiuidverbunden via a third switching valve 33 with an inert gas vent 35. The inert gas vent 35, for example, in a Ventmast a

Marine vehicle having the power generating arrangement 1, be integrated.

Once again viewed from the outer conduit volume 13, the third switching valve 33 is arranged in series with the first switching valve 25 and parallel to the second switching valve 31.

A pressure sensor 37 is provided which is arranged and arranged to detect the inert gas pressure in the outer conduit volume 13. The pressure sensor is Favor with the

Inertgasdruckstelleinrichtung 19 operatively connected. This preferably has a control unit, not shown here, which with the switching valves 31, 33, 35 and with the

Pressure sensor 37 is operatively connected.

Preferably, each cylinder bank A, B is assigned its own pressure sensor, wherein for the sake of simplicity, only one pressure sensor 37, which is assigned to the cylinder bank A, is shown here.

FIG. 1 also shows a non-return valve 39, which is designed as an overpressure safety valve and which is set up to close the inert-gas reservoir 27 in the event of an impermissible pressure rise upstream of the second switching valve 31

Inert gas vent 35 to vent.

Fig. 2 shows a schematic representation of the operation of the

Power generation arrangement 1 and in particular the Inertgasdruckstelleinrichtung 19. Here are on the horizontal axis, the time t and on a first, left vertical axis, a pressure p in the outer line volume 13, which is preferably detected by the pressure sensor 37, plotted on a second, right vertical axis a switching frequency f for the switching valves 25, 31, 33 is applied. In the following, only a control of the first switching valve 25 and of the second switching valve 31 will be described, because the representation given so far is limited to the behavior of the inert gas pressure control device in the event of a leakage, and thus a pressure drop. However, it is readily understood that in an inadmissible increase in pressure in an analogous manner, the first switching valve 25 and the third switching valve 33 could be controlled to pressure-relieve the outer line volume 13 via the feed container 23 to the inert gas vent 35 out. Such an impermissible pressure increase can For example, for thermal reasons, in particular result in a temperature increase in the engine room 7.

In the diagram of Figure 2, a target pressure s and a pressure band between a minimum pressure p _m j _n and a maximum pressure p _{max is} plotted, in which the pressure in the outer line volume 13 may deviate from the desired pressure ps, such

Pressure deviation without further action of the inert gas pressure 19 is tolerated.

A first curve Kl, which is shown here in solid lines, shows the variation of the actual pressure in the outer line volume 13 with the time t, a second curve K2, which is shown here in dashed lines, shows a switching frequency for the switching valves 25, 31 as a function of Time t.

Looking now at the pressure curve of the first curve Kl, starting from the left vertical axis of the diagram, it can be seen that the actual pressure decreases from the setpoint pressure ps with time t at a certain rate, for example because there is already a certain leakage, in particular an unavoidable residual leakage , is available. When the actual pressure reaches the minimum pressure p _m i _n , the second switching valve 31 and the first switching valve 25 are driven alternately at a first switching frequency f ₁ , whereby the pressure in the outer line volume 13 is increased stepwise. When the second switching valve 31 is closed and the first switching valve 25 is opened, inert gas flows from the feed tank 23 into the outer pipe volume 13 when the pressure in the feed tank 23 is higher than the pressure in the outer pipe volume 13. This is at a leakage in the outer line volume 13 is typically the case, wherein in particular the pressure in the inert gas reservoir 27 or in the inert gas generating device 29 is preferably higher than the setpoint pressure s. This then applies correspondingly also to the pressure in the feed container 23 after it has been filled from the inert gas reservoir 27. If the first switching valve 25 is closed and the second switching valve 31 is opened, inert gas flows from the inert gas reservoir 27 into the feed container 23. This happens - as already stated - alternately, the pressure in the outer

Line volume 13 is gradually increased.

When the pressure returns to the desired pressure value ps, the control of the switching valves 25, 31 is terminated. The actual pressure then drops at the rate already described above, which in particular can correspond to an unavoidable residual leakage rate. At a certain time, which is characterized here by a first leakage event LI, an increase in the leakage or, for the first time, an unintentional leakage beyond the unavoidable residual leakage occurs. It is therefore possible that a leak occurs for the first time, or that an already existing leak increases. This increases the leakage rate, and the actual pressure drops faster than before to the minimum pressure. Then, the switching valves 25, 31 are driven with a second, higher switching frequency f ₂ , and the pressure is in turn gradually, this time in a shorter sequence due to the shorter switching frequency, increased until it again reaches the setpoint pressure ps. Thereafter, the control of the switching valves 25, 31 stops.

The pressure then decreases with the second, larger leakage rate until it again reaches the minimum pressure pmin, in which case again the switching valves are actuated at the second switching frequency f ₂ until the pressure reaches the setpoint pressure p _s .

At a second time, characterized by a second leakage event L2, a critical increase in the leakage occurs, so that the leakage rate increases again and the pressure drops more rapidly to the minimum pressure p _m i _n . The switching valves 25, 31 are now controlled with a third, maximum switching frequency f ₃ , wherein the course of the first curve Kl shows that at this maximum switching frequency and the present leakage rate is just still possible, the inert gas pressure in the outer conduit volume 13 on the minimum

To maintain pressure level pm n.

The switching frequency for the switching valves 25, 31 is preferably selected as a function of a pressure variable, in particular of the actual pressure, a derivative of the actual pressure according to time and / or an integration of the actual pressure over a certain period of time. Depending on the switching frequency and the pressure variable, a leakage rate is preferably calculated. It is monitored whether the leakage rate exceeds a first threshold. This is in

present example, only the case after the second leakage event L2. The previous leakage is therefore tolerated. After the second leakage event L2, however, the leakage rate exceeds the predetermined, first threshold value, so that a first alarm signal AI is output. In the case of a third leakage event L3, the leakage rate increases again, so that it is no longer possible to maintain the pressure in the external power volume 13 despite the continued activation of the switching valves 25, 31 with the maximum switching frequency f ₃ . This sinks therefore further off. The leakage rate preferably exceeds a second threshold value, so that a second alarm A2 is output.

Preferably, a third threshold for the leakage rate is provided, wherein the

Internal combustion engine 3 is turned off when the leakage rate exceeds this third threshold.

In addition, it will be explained that an overpressure arising, for example, for thermal reasons in the outer line volume 13 - in particular when the maximum pressure p _ma x is reached - is achieved by alternately activating the third switching valve 33 and the first one

Switching valve 25 can be gradually reduced, the procedure is chosen here exactly analogous to the procedure for increasing the pressure in the outer line volume 13.

Overall, it turns out that the power generation arrangement 1, the vehicle and the method a very safe operation of internal combustion engines with fuel gas in particular for

Enable marine applications. In this case, no additional measuring devices are necessary for detecting a leakage rate, in particular no volumetric flow meter. This results in a double shutoff with respect to a separation of the fuel gas from the inert gas.

Furthermore, the power generation arrangement and in particular the

Inertgasdruckstelleinrichtung a simple structure, in particular no

Pressure control by means of a pressure control valve is necessary.

Claims

A power generating device (1) having an internal combustion engine (3) and a fuel gas supply (5) connected to the internal combustion engine (3) for supplying fuel gas, wherein

- The fuel gas supply (5) at least in the region of the internal combustion engine (3) has an at least double-walled line (9), the

- An inner pipe volume (11) for fuel gas, and

- An outer line volume (13), wherein

- The outer conduit volume (13) with an inert gas supply (15) is fluidly connected; and with

- A fuel gas pressure adjusting device (17) which is adapted to set a

Fuel gas pressure in the inner line volume (11), and with

an inert gas pressure setting device (19) which is set up to set a

Inert gas pressure in the outer conduit volume (13), wherein

- The fuel gas pressure adjusting device (17) and the Inergasdruckstelleinrichtung (19)

are arranged to select the inert gas pressure and the fuel gas pressure so that the inert gas pressure is higher than the fuel gas pressure.

2. Power generation arrangement (1) according to claim 1, characterized in that the inert gas supply (15) has a food container (23) which is connected to the outer

Line volume (13) via a first switching valve (25) is fluidly connected.

3. Power generating arrangement (1) according to one of the preceding claims, characterized in that the inert gas supply (15) has an inert gas reservoir (27) and / or an inert gas generating device (29), wherein the food container (23) with the

Inertgasreservoir (27) and / or fluidly connected to the inert gas generating means (29) via a second switching valve (31).

4. Power generating arrangement (1) according to any one of the preceding claims, characterized in that the feed container (23) via a third switching valve (33) with an inert gas vent (35) is fluidly connected.

5. A power generation arrangement (1) according to any one of the preceding claims, characterized in that a pressure sensor (37) for detecting an inert gas pressure in the outer conduit volume (13) is provided, which with the Inertgasdruckstelleinrichtung (19)

is actively connected.

6. power generation arrangement (1) according to any one of the preceding claims, characterized in that the Inertgasdruckstelleinrichtung (19) is adapted to adjust the Inertgasdrucks in the outer line volume (13) by cyclically driving the first switching valve (25) on the one hand, and the second switching valve ( 31) or the third switching valve (33) on the other.

7. Power generating arrangement (1) according to one of the preceding claims, characterized in that the Inertgasdruckstelleinrichtung (19) is adapted to control at least two switching valves (25,31,33) with a switching frequency in response to a pressure variable of the inert gas pressure in the outer line volume (13).

8. Power generating arrangement (1) according to one of the preceding claims, characterized in that the inert gas pressure adjusting device (19) is adapted to determine a leakage rate from the outer line volume (13) based on a current one

Switching frequency and a pressure amount of the inert gas pressure in the outer pipe volume (13).

9. vehicle (100), with a power generating arrangement (1) according to one of

previous claims.

10. A method for adjusting an inert gas pressure in an outer conduit volume (13) of an at least partially double-walled fuel gas supply (5), wherein the

Inert gas pressure in an outer pipe volume (13) of the fuel gas supply (5) is selected to be higher than a fuel gas pressure in an inner pipe volume (11) of

Fuel gas supply (5).