DE102013207838B3 - Mixture-compressing gas engine and method for equalizing at least two cylinders of a mixture-compressing gas engine - Google Patents

Abstract

A mixture-compressing gas engine (7) with at least a first and a second cylinder (11), and with a compressor device (13) which generates a compressed air-fuel gas mixture and which is connected to the cylinders (11) via a common feed line (15) is in fluid communication, with each cylinder (11) being assigned at least one feed channel (17, 19) branching off from the common feed line (15) for feeding the compressed air-fuel gas mixture into the cylinder (11). The mixture-compressing gas engine (7) is characterized in that the feed channel (17) assigned to the first cylinder (11) has a cross-sectional constriction (31), the cross-sectional constriction (31) being matched to the cross-section of the at least one feed channel assigned to the second cylinder is that when the gas engine (7) is in operation, a substantially equal charge is achieved for all cylinders (11).

Description

The invention relates to a mixture-compressing gas engine according to the preamble of claim 1 and to a method for equalizing at least two cylinders of a mixture-compressing gas engine according to claim 8.

Mixture-compressing gas engines of the type discussed here have at least a first and a second cylinder, typically a plurality of cylinders. A compressor device generates a compressed air-fuel gas mixture, which is supplied to the cylinders via a common feed line. In this case, each cylinder is assigned at least one branching off from the common feed line feed channel to guide the compressed air-fuel gas mixture into the individual cylinders. In particular, by the geometry of the common feed line and / or the individual, leading to the cylinders feed channels, and possibly also due to the geometry of an exhaust system or the pressure conditions in this, there is a certain unequal distribution with respect to a filling of the cylinder with the air-fuel gas mixture , This unequal distribution results in characteristic values which represent the individual performance of the different cylinders differing from one another in a cylinder-specific manner, the cylinders having, for example, different indicated mean pressures, different exhaust-gas temperatures or different distances from the knocking limit. Here individual cylinders occupy a priority position and thereby limit the entire engine. In this case, there is a limitation, especially with regard to the knock limit, wherein the entire gas engine is limited by those cylinders which have the smallest distance to this. This results in a limit of the total engine power upwards. Due to the unequal distribution of the overall efficiency of the gas engine is deteriorated. It is therefore desirable to match the fillings of the individual cylinders as far as possible.

This is from the European patent EP 0 471 169 B1 a method is known in which differences in the filling of each cylinder is equated by a corresponding actuation of the inlet valves. This procedure is comparatively complicated.

From the German patent application DE 101 24 859 A1 is an inlet channel means for supplying a gas to a combustion chamber of an internal combustion engine, wherein in an inflow passage, a passage opening limiting adjusting device is provided, wherein the position of the passage opening relative to the swirl passage portion is adjustable in an adjustable manner. In one embodiment, it is provided that the passage opening forms a throttle cross-section.

From the publication DE 694 05 247 T2 is a method for improving the performance of under an average boost pressure charged primarily by an exhaust gas turbocharger and air-flushed internal combustion engine, wherein a plurality of cylinders are combined on the same Auslasskrümmer.

The invention has for its object to provide a mixture-compressing gas engine and a method for equalization of at least two cylinders of a mixture-compressing gas engine, which do not have the disadvantages mentioned. In particular, it should be possible in the mixture-compressing gas engine or by means of the method to adjust the filling of the individual cylinders in a simple and cost-effective manner.

The object is achieved by providing a mixture-compressing gas engine having the features of claim 1. This is characterized in that the feed channel assigned to the first cylinder has a cross-sectional constriction which is matched to the cross-section of the at least one feed channel assigned to the second cylinder such that during operation of the gas engine an essentially equal filling is achieved for all cylinders. The mixture-compressing gas engine thus has a first cylinder, to which a first supply channel branching off from the common supply line is assigned. It also has a second cylinder, the second, is assigned from the common supply branching supply channel. The first supply channel has a cross-sectional constriction, which is matched to the cross section of the second feed channel, that with regard to the common feed line and the feed channels existing flow conditions are influenced such that an equalization of the cylinder charge for the first cylinder and the second cylinder in operation the gas engine is effected. Due to the cross-sectional constriction so existing differences in the cylinder filling are compensated by appropriate design of the flow geometry of the first feed channel. Thus, the cylinders are equalized in terms of their individual performance, without the need for a complicated control process. Rather, a simple and inexpensive, purely constructive solution to the underlying problem is created by using the cross-sectional constriction, the flow through the supply line or the various feed channels is affected. Due to the equality of the cylinder filling results in a substantially equal distance of all cylinders to the knock limit and a in Essentially also the same distance to the ignition limit. Thus, individual cylinders are no longer limiting the overall performance of the gas engine, and it is possible to utilize a larger power interval with the gas engine. At the same time, the overall efficiency of the gas engine is higher because it has no more disadvantaged in terms of their filling cylinder.

In the mixture-compressing gas engine, the cross-sectional constriction is formed as a pipe piece disposed on a gasket for a cylinder head of the gas engine. The tube piece arranged on the seal thus represents an exemplary embodiment of a diaphragm. It is preferably connected to the seal such that the gas mixture can not flow past between the seal and the tube piece, but instead has to flow through the tube piece. The pipe section arranged in the feed channel thus limits its passage cross section.

Preferably, the gas engine comprises more than two cylinders, for example six, eight, ten, twelve, sixteen or twenty cylinders. Also more than twenty cylinders are possible. Each cylinder is associated with at least one branching from the common feed channel. In this case, a number of feed channels, which is preferably greater than one and preferably less than or equal to the total number of cylinders reduced by one, in each case a cross-sectional constriction, wherein the individual cross-sectional constrictions are chosen or tuned to each of the other cylinders associated feed channels that During operation of the gas engine results in a substantially equal filling for all cylinders. In this case, typically cylinders that would receive a large filling without the cross-sectional constriction, throttled by means of the cross-sectional constriction, wherein cylinders that would otherwise receive a comparatively small filling, are not or hardly throttled by a cross-sectional constriction. It is essential that all cross-sectional constrictions and remaining open cross sections without cross-sectional constriction in the various feed channels are coordinated so that ultimately results in the operation of the gas engine for all cylinders, an essentially equal filling.

An embodiment of the mixture-compressing gas engine is preferred in which each cylinder is assigned two feed channels. Preferably, in the cylinders to which a feed channel is associated with a cross-sectional constriction, a cross-sectional constriction is arranged only in one of the two feed channels. Alternatively, it is also possible to provide in each case a cross-sectional constriction in both feed channels of a corresponding cylinder.

Of course, an embodiment of the gas engine is possible in which all cylinders a feed channel is assigned, which has a cross-sectional constriction.

A mixture-compressing gas engine is preferred, which is characterized in that the cross-sectional constriction is formed as a diaphragm. The term "aperture" is generally a separate from the feed trained, but arranged in this element addressed, which narrows the passage cross section of the feed channel and thus throttles the feed. The aperture thus has a passage cross-section which is smaller than a minimum passage cross-section along the feed channel, if no aperture is arranged in this.

In another embodiment, it is possible that the cross-sectional constriction is formed integrally with the feed channel, in particular with a wall thereof. In this embodiment, the cross-sectional constriction is preferably formed as a projection, in particular as an annular circumferential projection of the wall. While in this embodiment reduces a number of parts and additional elements can be avoided, however, requires a precise analysis of the flow conditions in the supply line and the feed channels before the actual production of the gas engine in order to ultimately make the walls of the feed channels so that equality the different cylinders is reached. In contrast, the arrangement of separate elements in the feed channels, in particular of panels, the advantage that they can be subsequently adapted to the conditions of the specific gas engine and arranged according to needs.

Preferably, the pipe section, as which the cross-sectional constriction is formed integrally formed with the seal. Alternatively, it is also possible that the pipe piece is joined to the seal, in particular welded to it, soldered, glued or fastened in another suitable manner to this. This results in a particularly simple handling of the diaphragm, which can be arranged together with the seal in the region of the cylinder head and thus in the feed channel.

In particular, a mixture-compressing gas engine is preferred, which is characterized in that the pipe section is welded to the gasket. Particularly preferably, the tube piece is laser-welded to the seal. The welded joint between the pipe section and the seal is simple and inexpensive to produce and at the same time gas-tight. A laser weld is in particular little expensive, inexpensive way to produce.

A mixture-compressing gas engine is also preferred which is characterized by having two exhaust conduits in fluid communication with different cylinders. Thus, the gas engine preferably includes a first exhaust conduit and a second exhaust conduit, wherein the first exhaust conduit is in fluid communication with a first group of cylinders, the second exhaust conduit being in fluid communication with a second group of cylinders. The first group of cylinders includes cylinders other than the second group of cylinders, with no cylinder of the gas engine in both the first group and the second group of cylinders. The exhaust gas of the various groups of cylinders is thus guided at least partially through two separate exhaust pipes. It can be seen here that, depending on the design of the exhaust pipes, different exhaust back pressures can exist for the different groups of cylinders and also for different cylinders within the groups. This uneven pressure distribution counteracts a uniform charge filling of the cylinder at a charge change. In order to even out the exhaust back pressure between the various groups of cylinders, but preferably also between the individual cylinders of a group, a cross connection is provided, through which the exhaust pipes are fluidly connected to each other. The cross-connection creates a fluid path for pressure equalization between the exhaust pipes, so that exhaust back pressure is homogenized not only between the cylinder groups but also between the individual cylinders within a group. This helps to achieve the goal of uniformly filling the various cylinders.

With the aid of the transverse connection, it is possible, in particular, to avoid excessive cross-sectional constrictions in the feed channels. The equalization or homogenization of the exhaust backpressure thus causes, in particular, that the limiting cylinders on the upstream side do not have to be throttled too much. Excessive cross-sectional constrictions in the feed channels are disadvantageous because they undesirably limit the capacity of the cylinder and thus in turn have a negative effect on the performance or the efficiency of the gas engine.

The cross connection is preferably arranged on a side of the exhaust pipes, which - viewed in a main flow direction of the exhaust gas - facing a common manifold. Here, by a main flow direction is meant the direction in which the exhaust gas flows along the exhaust pipes from the cylinders to an exhaust device such as an exhaust. It is possible that, as part of a pressure equalization between the exhaust pipes and an at least partially opposite flow results, in particular in the region of the cross connection. This is not contrary to the fact that the main flow direction of the exhaust gas is predetermined by its path from the cylinders to the ejector. The two exhaust pipes open in a preferred embodiment in a common manifold, which further - possibly via at least one exhaust aftertreatment device, such as an oxidation catalyst - leads to the ejection device. It is obvious that in the mouth region of the exhaust pipes in the common manifold already exists a fluid connection between the two exhaust pipes and thus also virtually a cross-connection. In this embodiment, therefore, an additional cross-connection on the side of the exhaust pipes is provided so far, which is opposite to the common manifold or the mouth region. This leads to an additional equalization of the exhaust back pressure.

It is also preferred a mixture-compressing gas engine, which is designed as a V-engine. Here are two cylinder banks, thus two rows of juxtaposed cylinders, in the form of a V opposite. Each cylinder bank is assigned an exhaust pipe. There is provided a cross connection through which the exhaust pipes are fluidly connected to each other. This is also used in this embodiment to equalize the exhaust back pressure between the cylinder banks on the one hand and between the individual cylinders of a cylinder bank on the other hand, and thus to support a homogeneous filling of the cylinder. The transverse connection is preferably provided-along a longitudinal extent of the exhaust gas lines-opposite a mouth region of the exhaust gas lines into a common manifold for the exhaust gas. Thus, in such an embodiment, not only in the mouth region, a cross-connection between the exhaust pipes is provided, but also on the - viewed in the longitudinal direction - the mouth region opposite end of the exhaust pipes. This leads to a pressure equalization between the exhaust pipes, so that the exhaust back pressure equalized.

A mixture-compressing gas engine is also preferred, which is characterized in that the at least one cross-sectional constriction is arranged in the supply passage upstream of an intake valve of the cylinder. In the feed channel, therefore, an inlet valve is arranged, which is opened to the air-fuel gas mixture of the Feed channel to flow into a combustion chamber of the cylinder, and which is closed to seal the combustion chamber with respect to the feed channel. The cross-sectional constriction in the feed channel, which influences the flow therethrough, is preferably arranged upstream of the inlet valve, that is to say on its side facing away from the combustion chamber.

The mixture-compressing gas engine is preferably operable with a methane-containing gas as fuel, preferably natural gas, biogas, lean gas or a special gas. It is particularly preferably used to drive a generator for power generation, for example in a gas power plant or in a combined heat and power plant, where it is used for continuous load, for base load, peak load or emergency power. It is also possible that the mixture-compressing gas engine for driving a motor vehicle, such as a locomotive - optionally in combination with an electric drive - a construction vehicle, a self-propelled harvesting vehicle or a ship is provided. Furthermore, it is possible that the mixture-compressing gas engine for driving external units, such as fire pumps, especially on rigs, is provided. Likewise, the mixture-compressing gas engine for energy supply in hard to reach areas, for example on drilling rigs, be provided.

The object is also achieved by providing a method with the steps of claim 8. In this case, a characteristic value is measured during operation of the gas engine for each cylinder, which represents an individual power of the cylinder. The characteristic values measured for the individual cylinders are compared with each other. In this way it is possible to determine which cylinders limit the overall performance of the gas engine either up or down by their distance to the knock limit or to the ignition limit. In general, it is possible to use the characteristic values to determine an unequal distribution of the individual outputs of the cylinders. On the basis of the comparison of the characteristic values, at least one cross-section is defined for at least one feed channel assigned to a cylinder for feeding a compressed air-fuel gas mixture into the cylinder. Thus, it is possible to define a throttling for the at least one supply channel in order to throttle, for example, a cylinder with a high performance characteristic or to reduce it with respect to its performance characteristic value. The at least one cross section is therefore determined or determined in such a way that the characteristic values of the different cylinders are matched to one another. At least one cross-sectional constriction, which is formed as a tube piece arranged on a gasket for a cylinder head of the gas engine, is arranged in the feed channel in order to realize the cross section defined for the feed channel. In this way, the limiting cylinders can be throttled flow-optimized without the use of additional actuators on the mixture side to even out the cylinder filling. Overall, the advantages that have already been explained in connection with the mixture-compressing gas engine are realized.

Preferably, corresponding cross-sections are defined for more than one feed channel, and cross-sectional constrictions are arranged in more than one feed channel in order to realize the specified cross-sections. The different cross-sectional constrictions are matched to one another on the basis of the characteristic values in such a way that the characteristic values are standardized and thus the fillings of the individual cylinders are matched to one another. It is possible that in all feed channels of the gas engine cross-sectional constrictions are arranged, or that each cylinder has a feed channel in which a cross-sectional constriction is arranged. Alternatively, it is possible that a cylinder having the smallest characteristic value does not receive a cross-sectional constriction in an associated feed channel, while the cylinders with higher characteristic values are throttled by means of cross-sectional constrictions. It is also possible that, with any number of cylinders greater than one but less than the total number of cylinders minus one, a cross-sectional constriction is placed in an associated feed channel.

A method is also preferred, which is characterized in that at least one aspect ratio is calculated for at least two feed channels, which are assigned to different cylinders. On the basis of the cross-sectional ratio, it is then possible to calculate a reduced cross-section and thus a cross-sectional constriction to be arranged in the feed channel, in any case for one of the two feed channels. The aspect ratio is preferably calculated based on a quotient of the characteristics associated with the cylinders. In the simplest case, it is possible that the aspect ratio is proportional to a reciprocal of the quotient of the characteristic values. In this way, it is ensured that the cross-section of a feed channel to a powerful, well-filled cylinder is throttled more than the cross-section of a feed channel, which is associated with a low-performance, poorly filled cylinder. Of course, it is possible to use a suitable proportionality factor other than one. In the simplest case, however, it is preferred that the aspect ratio is directly inversely proportional to the quotient is the characteristic value with a proportionality factor of one.

A method is also preferred which is distinguished by the fact that a mean pressure of the cylinders is measured as a characteristic value representing a cylinder-specific power. Particularly preferably, the indicated mean pressure is used as characteristic value. Alternatively, it is also possible to use the effective medium pressure or the Reibmitteldruck. Other suitable quantities can also be measured as a characteristic value. For a pressure measurement, a pressure sensor provided in the cylinder or integrated in the cylinder is preferably used.

Finally, a method is preferred which is characterized in that a diaphragm is arranged in the feed channel as a cross-sectional constriction. Preferably, as a diaphragm arranged on a seal for a cylinder head of the gas engine pipe section is arranged in the feed channel. The procedure described here has the advantage that the distribution of the characteristic values over the cylinders can be measured individually for a specific gas engine, with suitable diaphragms then being able to be arranged in the supply ducts in a simple and cost-effective manner. This can be done once after a production of the engine, for example in the context of test bench tests. If the motors in a series differ only slightly from each other, it is also possible to set the cross-sectional constrictions once for the entire series. It then requires no more measurements for the individual motors of the corresponding series. The arrangement of orifices in feed channels also has the advantage that it can be retrofitted with engines already in operation, to equalize their cylinder filling. This can be done in a simple and inexpensive way. It does not require complex and complex control during operation of the engines, because equality is based on purely mechanical means, namely on a once performed, geometric throttling of the limiting cylinder.

The description of the gas engine on the one hand and the method on the other hand are to be understood as complementary to each other. In particular, method steps which have been explicitly or implicitly explained in connection with the gas engine are preferably also individually or in combination with one another and also steps of an embodiment of the method. Conversely, features explained explicitly or implicitly in connection with the method are preferably features of an embodiment of the gas engine, individually or in combination with each other.

The invention will be explained in more detail below with reference to the drawing. Showing:

1 a diagrammatic representation of unequal characteristics for 3 cylinders;

2 a partial sectional view of an embodiment of a gas engine;

3 a detailed view of another embodiment of a gas engine, and

4 a diagrammatic view of an embodiment of the method.

1 shows a diagrammatic representation of a quantity G plotted against the time t, which can be used as a characteristic value representing a cylinder-specific performance of a gas engine. The size G may be, for example, a mean pressure, preferably an indicated mean pressure of the respective cylinder. Dashed is a first curve 1 representing the mean of the quantity G plotted against the time t for a first cylinder. The actual values of the quantity G deviate from the mean depending on the time t. Analogously, a second curve is dash-dotted 3 representing a corresponding average value G for a second cylinder. A third, small dashed curve 5 represents a third mean of the magnitude G for a third cylinder. It turns out that through the curves 1 . 3 . 5 shown average values of the size G and thus also the cylinder-individual performance representing characteristic values for the first, the second and the third cylinder differ from each other. In this case, a comparatively large characteristic value is assigned to the first cylinder, while comparatively smaller characteristic values are assigned to the second and the third cylinder. Represent the curves 1 . 3 . 5 For example, mean values of indicated mean pressures of the cylinders, the first cylinder 1 a comparatively high indicated mean pressure, while the second and the third cylinder have comparatively low indicated mean pressures. Thus, in the present case, the first cylinder is limiting for the overall performance of the gas engine in the upper power range, in particular defining a distance to the knock limit. Conversely, it is possible that the third cylinder 5 the total power of the gas engine is limited down to the ignition limit.

Based on 1 can also illustrate the following: If the gas engine is designed as a V-engine with two cylinder banks, is the first curve 1 preferably assigned to a cylinder of a first cylinder bank, while the second curve 3 and the third turn 5 each associated with a cylinder of a second cylinder bank. It turns out a relatively large distance between the characteristic values assigned to the individual cylinder banks, with smaller differences between cylinders of a cylinder bank, which are nonetheless measurable. Overall, the gas engine due to the unevenly distributed cylinder-individual performance on a lower overall efficiency and a relatively narrow power range. This is essentially due to the fact that the fillings of the individual cylinders differ from each other. In this case, in particular, the first cylinder has a large filling, while the second cylinder and the third cylinder have a comparatively small filling, wherein in turn the third cylinder has a smaller filling than the second cylinder.

2 shows a partial sectional view through an embodiment of a mixture-compressing gas engine 7 , Specifically, the viewer looks in 2 almost from a combustion chamber of the gas engine 7 on a cylinder head 9 a cylinder 11 that completes the combustion chamber. In this case, however, the cutting plane is displaced into the cylinder head starting from the combustion chamber, so that here channels and openings are visible, which are actually sealed relative to the combustion chamber by wall sections cut away here. Only schematically shown is a compressor device 13 , which produces a compressed air-fuel gas mixture, which via a likewise only schematically shown here, common supply line 15 the cylinder 11 is fed, which the cylinder head 9 having. From the common supply line 15 branch here two feed channels 17 . 19 from, through which the compressed air-fuel gas mixture in a combustion chamber, not shown, of the cylinder 11 is feasible. In this case, the cylinder head 9 here two intake valves 21 . 23 on, wherein a first inlet valve 21 the first supply channel 17 is assigned, and wherein a second inlet valve 23 the second feed channel 19 assigned. In an intake stroke of the gas engine 7 become the intake valves 21 . 23 opened to let the air-fuel gas mixture into the combustion chamber. In other cycles of the gas engine 7 are the intake valves 21 . 23 closed, so in this case the feed channels 17 . 19 are sealed to the combustion chamber.

The cylinder head 9 also has two exhaust valves 25 . 27 on, through the exhaust gas from the combustion chamber of the cylinder 11 can be omitted in an exhaust pipe, not shown here. In addition, the cylinder head includes 9 a hole 29 which preferably serves to secure a spark plug through the bore 29 into the combustion chamber or into an antechamber of the cylinder 11 protrudes.

In the illustrated embodiment of the gas engine 7 points the cylinder 11 assigned, first feed channel 17 a cross-sectional constriction 31 on. This one is here as a panel 33 , hence as separate from the feed channel 17 provided, but arranged in this and its passage cross-section effectively narrowing element formed. Here is the cross-sectional constriction 31 so on the cross section of further, the other cylinders of the gas engine 7 matched supply channels tuned that during operation of the gas engine 7 gives a substantially equal filling for all cylinders. Using the cross-sectional constriction 31 is in particular the cylinder 11 flow-optimized throttled, thus limited in terms of its filling, without the need for additional use of actuators on the mixture side.

In the second, the cylinder 11 associated feed channel 19 here no cross-sectional constriction is arranged. This feed channel 19 is therefore not throttled. The throttling or limitation of the cylinder 11 therefore results in the in 2 illustrated embodiment completely by the in the first feed channel 17 arranged cross-sectional constriction 31 ,

In the illustrated embodiment, the cross-sectional constriction 31 or the aperture 33 as a piece of pipe 35 trained, that at a seal 37 is arranged. The seal 37 here preferably serves the seal of the cylinder head 9 in a transitional area to the common supply line 15 ,

Particularly preferred is the pipe section 35 with the seal 37 welded, in particular laser welded. In the illustrated embodiment, the pipe section 35 into a hole 39 the seal 37 inserted and welded in the region of its circumference with this, preferably laser welded.

In the area of the second feed channel 19 shows the seal 37 a second hole 41 on, whose passage cross section either the corresponding passage cross section of the second feed channel 19 at the place of the seal 37 equal to or greater than this is formed. In any case, the passage cross-section is in the region of the bore 41 chosen so that these are not limiting or throttling for the second feed channel 19 acts.

It still shows that the cross-sectional constriction 31 upstream of the first intake valve 21 is arranged, through the pipe section 35 inflowing air-fuel mixture along an arrow P through the first feed channel 17 to the first intake valve 21 flows.

3 shows a schematic representation of a detail of another embodiment a gas engine 7 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. The gas engine 7 is designed here as a V-engine and has two only schematically indicated cylinder banks, namely a first cylinder bank 43 and a second cylinder bank 45 , In the illustrated embodiment, the gas engine 7 designed as a 12-cylinder engine, each of the cylinder banks 43 . 45 includes six cylinders. The first cylinder bank 43 is a first exhaust pipe 47 assigned to the exhaust of the cylinder of the first cylinder bank 43 initiated and through which this exhaust is derived. The second cylinder bank 45 is a second exhaust pipe 49 assigned to the exhaust of the cylinder of the second cylinder bank 45 initiated and through which this exhaust is derived.

Between the first exhaust pipe 47 and the second exhaust pipe 49 is a cross connection 51 provided through which the exhaust pipes 47 . 49 are in fluid communication with each other. It turns out that in the illustrated embodiment - in the longitudinal direction of the exhaust pipes 47 . 49 seen - at a first end of a mouth area 53 is arranged, in which the exhaust pipes 47 . 49 in a common manifold 55 lead. The common bus 55 leads - optionally via at least one exhaust aftertreatment device - to an ejector for the exhaust gas, such as an exhaust. In this respect, a main flow direction of the exhaust gas from the cylinders of the cylinder banks 43 . 45 through the exhaust pipes 47 . 49 on the common bus 55 predetermined to the ejector.

The cross connection 51 is on - along the longitudinal extension of the exhaust pipes 47 . 49 or seen against the main flow direction of the exhaust gas - the common manifold 55 or the mouth area 53 opposite side of the exhaust manifolds 47 . 49 arranged. About the cross connection 51 results in a pressure equalization between the exhaust pipes 47 . 49 so that the two cylinder banks 43 . 45 be largely equal in terms of exhaust back pressure. This leads - over the cross-sectional constriction 31 In addition - to a homogenization of the cylinder filling, since a charge change in the individual cylinders takes place against a balanced exhaust back pressure.

Overall, this leads to at least one cross-sectional constriction 31 as well as the cross connection 51 to an approximation of the cylinder fillings and thus to a homogenization of the cylinder-individual power output of the gas engine 7 , Thus results - as already described - for the gas engine 7 Overall, a better overall efficiency, by shifting the global knock limit, and adding the gas engine 7 range of performance is extended because it is no longer limited by individual, lifted cylinder up and / or down.

The cross connection 51 is preferably designed as a piece of pipe which the exhaust pipes 47 . 49 connects to each other, wherein the pipe piece is preferably welded to these.

4 shows a schematic representation of an embodiment of the method. In a first step S1, the method is started. In a second step S2, a characteristic value is measured for each cylinder, which represents the individual power of the cylinder. In this case, an indicated mean pressure of the cylinder is preferably measured. In a step S3, the cylinder-individually measured characteristic values are compared with one another. Quotients of the characteristic values associated with the cylinders are preferably particularly preferred, based on the lowest for a cylinder of the gas engine 7 measured characteristic value formed.

In a step S4 are cross sections for supply channels of the gas engine 7 set, which serve the supply of a compressed air-fuel gas mixture into the individual cylinders. This is done on the basis of the comparison of the characteristic values. Particular preference is given to determining cross-sectional ratios for the feed channels, these being preferably related to the cross-section of the feed channel associated with the cylinder having the lowest characteristic value, and thus the lowest cylinder filling.

Particularly preferably, the cross sections for the feed channels of the individual cylinders are calculated proportional to the reciprocal of a quotient of the characteristic value of the cylinder in question divided by the lowest characteristic value. In this way, it is possible with relatively little effort to set the different cross sections so that the characteristics of the gas engine 7 be aligned with each other during operation. In this case, preferably, the cylinder with the lowest characteristic value is not throttled with respect to the cross section of a feed channel, while the cylinders with higher characteristic grades are throttled depending on the amount of their characteristic value with regard to the cross section of the respective associated feed channels.

The time-averaged, indicated mean pressure of a cylinder is particularly preferably used as characteristic value.

Finally, in a step S5 in the supply channels, for which this is provided, a cross-sectional constriction is arranged in order to realize the respective fixed cross-section and the respective feed channels in such a stepped throttled, that the filling of the individual cylinders is equal to each other. For this purpose, a diaphragm, preferably a tube piece arranged on a seal for a cylinder head of the gas engine, is preferably arranged in the feed channels as a cross-sectional constriction.

In a step S6, the method ends.

Overall, it has been found that with the mixture-compressing gas engine and the method it is possible to equalize the cylinder fillings and thus also the cylinder-specific performance, so that previously disadvantaged cylinders can be equalized with respect to the filling, whereby overall the overall global knocking limit is shifted in favor of a better overall efficiency can. At the same time, a broader range of performance is opened up for the gas engine without the need for complicated control procedures in the operation of the gas engine.

Claims (10)

Mixture-compacting gas engine ( 7 ) with at least one first and one second cylinder ( 11 ), and with a compressed air-fuel gas mixture producing compressor device ( 13 ), which have a common supply line ( 15 ) with the cylinders ( 11 ) is in fluid communication with each cylinder ( 11 ) at least one of the common supply line ( 15 ) branching feed channel ( 17 . 19 ) for supplying the compressed air-fuel gas mixture into the cylinder ( 11 ), characterized in that the first cylinder ( 11 ) associated feed channel ( 17 ) a cross-sectional constriction ( 31 ), wherein the cross-sectional constriction ( 31 ) is adapted to the cross section of the at least one feed channel assigned to the second cylinder such that during operation of the gas engine ( 7 ) a substantially equal filling for all cylinders ( 11 ), the cross-sectional constriction ( 31 ) as a piece of pipe ( 35 ) formed on a seal ( 37 ) for a cylinder head ( 9 ) of the gas engine ( 7 ) is arranged. Mixture-compacting gas engine ( 7 ) according to claim 1, characterized in that the cross-sectional constriction ( 31 ) as a diaphragm ( 33 ) is trained. Mixture-compacting gas engine ( 7 ) according to one of the preceding claims, characterized in that the pipe section ( 35 ) in one piece with the seal ( 37 ) is trained. Mixture-compacting gas engine ( 7 ) according to one of the preceding claims, characterized in that the pipe section ( 35 ) with the seal ( 37 ) is welded, preferably laser welded. Mixture-compacting gas engine ( 7 ) according to one of the preceding claims, characterized in that the gas engine ( 7 ) two exhaust pipes ( 47 . 49 ) with different cylinders ( 11 ) are in fluid communication, wherein a cross-connection ( 51 ) is provided, through which the exhaust pipes ( 47 . 49 ) are fluidly connected to each other, wherein the cross-connection ( 51 ) preferably on a - seen in a main flow direction of the exhaust gas - a common manifold ( 55 ) opposite side is arranged. Mixture-compacting gas engine ( 7 ) according to one of the preceding claims, characterized in that the gas engine ( 7 ) as a V-engine with two cylinder banks ( 43 . 45 ), each cylinder bank ( 43 . 45 ) an exhaust pipe ( 47 . 49 ), wherein a cross-connection ( 51 ) is provided, through which the exhaust pipes ( 47 . 49 ) are fluidly connected to each other, wherein the cross-connection ( 51 ) preferably - along a longitudinal extent of the exhaust pipes ( 47 . 49 ) - opposite a mouth region ( 53 ) of the exhaust pipes ( 47 . 49 ) into a common bus ( 55 ) is provided for the exhaust gas. Mixture-compacting gas engine ( 7 ) according to one of the preceding claims, characterized in that the at least one cross-sectional constriction ( 31 ) in the feed channel ( 17 ) upstream of an inlet valve ( 21 ) of the cylinder ( 11 ) is arranged. Method for equalizing at least two cylinders ( 11 ) of a mixture-compressing gas engine ( 7 ), the method comprising the steps of measuring a characteristic value (G) representing an individual power during operation of the gas engine ( 7 ) for each cylinder ( 11 ); Comparing the for each cylinder ( 11 ) measured characteristic values (G); Specify at least one cross section ( 31 ) for at least one feed channel associated with a cylinder ( 17 ) for supplying a compressed air-fuel gas mixture into the cylinder ( 11 ) on the basis of the comparison of the characteristic values (G) so that the characteristic values (G) are determined by means of the defined cross-section ( 31 ) and arranging at least one cross-sectional constriction ( 31 ), which act as a seal ( 37 ) for a cylinder head ( 9 ) of the gas engine ( 7 ) arranged pipe section ( 35 ) is formed in the feed channel ( 17 ) to realize the specified cross-section. A method according to claim 8, characterized in that at least one aspect ratio for at least two feed channels ( 17 ), the different cylinders ( 11 ), preferably based on a quotient of the cylinders ( 11 ) associated characteristic values (G) is calculated. Method according to one of claims 8 and 9, characterized in that as a cylinder-specific performance representing characteristic value (G) a mean pressure, preferably an indicated mean pressure of the cylinder ( 11 ) is measured.

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