JP6095470B2 - Internal combustion engine - Google Patents

Description

  The present invention relates to a two-cycle large-size diesel engine including a turbocharger and an exhaust gas recirculation unit described in the preamble of claim 1.

  In particular for large internal combustion engines, the turbocharger stage is used to extract energy from the exhaust gas coming from the engine and thus compress the charge air to be supplied to the engine or the charge gas to be supplied to the engine to improve combustion. Is commonly used. Particularly in a multi-cylinder engine, a plurality of turbochargers that form a turbocharger stage as a whole are also used for this purpose.

  In addition to measures such as turbocharging for recovering energy from exhausted combustion gas or exhaust gas, today, the focus is on clean combustion as much as possible. For this reason, part of the exhaust gas is often recirculated to the intake side of the engine, thus lowering the combustion temperature and thus reducing the NOx emissions of the engine.

  A gas treatment device such as an exhaust gas cleaning device is often provided in the recirculation pipe so that sulfur particles and soot particles contained in the recirculated exhaust gas are not recirculated to the combustion chamber unintentionally. ing. This is because when they are recirculated to the combustion chamber, exhaust gas recirculation will certainly lead to a reduction in engine NOx emissions, but will instead increase the sulfur load in the exhaust emissions. Thus, for example, our Patent Document 1 shows an exhaust gas recirculation type diesel engine having a gas cleaning device in a recirculation line.

  When circulating through such a gas treatment device, a pressure drop occurs in the recirculated exhaust gas. The pressure in the recirculated exhaust gas, which finally matches the pressure in the combustion chamber at the time when the recirculated exhaust gas is taken out, is often not so high even when not flowing through such a gas treatment device, and the exhaust gas is sucked in without an additional compressor. It can be introduced directly into the scavenging air or supply air in the path. This is especially true on the high side of the scavenging gas, that is, on the downstream side of the scavenging air or turbocharger or turbocharger stage where the scavenging air or charge air to be supplied to the engine is compressed. This is the case when the circulation line pours into the suction path. Introducing the recirculated exhaust gas into the intake passage on the scavenging gas high pressure side and at the same time branching the recirculation line from the exhaust passage upstream of the turbocharger turbine means that the exhaust gas to be recirculated is still in the turbocharger It is desirable to prevent the occurrence of a situation in which the efficiency of the internal combustion engine is reduced by being inserted into one or a plurality of supply air compressors.

  In the turbo turbo diesel engine described in Patent Document 2, the exhaust gas is recirculated on the high pressure side, that is, the recirculation pipe is branched from the exhaust path on the upstream side of the turbocharger turbine. Is pouring into the suction path downstream. Another power turbine that circulates exhaust gas that is not recirculated but exhausted to the environment is integrated into the exhaust pipe on the downstream side of the turbocharger turbine, which is useful for compressing the supply air. The path is connected to the crankshaft via a controllable hydraulic clutch and transmission. The reflux exhaust gas is cooled by a heat exchanger attached to the recirculation line. This heat exchanger is implemented as a steam generator and serves to drive the steam turbine together with other appropriately formed heat exchanger-steam generators in the exhaust gas line downstream of the power turbine. The steam turbine emits drive output to the crankshaft via a hydraulic clutch or to an auxiliary machine in the drive system, such as a generator. On the other hand, energy that is not used by the turbocharger of the engine can be extracted from the exhaust gas discharged into the environment by the power turbine. However, according to Patent Document 2, the additional power turbine mainly adjusts the back pressure generated in the power turbine that becomes an obstacle to the discharged exhaust gas by controlling the hydraulic clutch that couples the power turbine to the crankshaft. At the same time, it is useful for adjusting the ratio of the recirculated exhaust gas to the exhausted exhaust gas and the pressure of the recirculated exhaust gas that is dominant on the upstream side of the turbocharger in the exhaust path. That is, the hydraulic clutch that couples the power turbine to the crankshaft is eventually adjusted to increase the recirculated exhaust gas to a prevailing pressure level on the scavenging gas high pressure side in the intake path.

  On the other hand, the exhaust gas is recirculated on the high-pressure side, that is, a two-cycle large-sized diesel that recirculates from the exhaust path upstream of the turbocharger turbine and pours into the intake path downstream of the turbocharger compressor In an engine, an electrically driven compressor is usually provided in the recirculation line in order to raise the recirculated exhaust gas to a prevailing pressure level on the high side of the scavenging gas in the intake path. 3 (International Application No. PCT / DK93 / 00398). There, a gas scrubber is in the recirculation line upstream of the compressor. The electrical output required to drive the compressor in the recirculation line can be taken from, for example, a generator set provided to drive the onboard power supply of the ship driven by the internal combustion engine. However, this reduces the overall efficiency of the internal combustion engine.

  Another proposal is to drive a fan in the recirculation line through a hydraulically operated turbine that is supplied with high-pressure hydraulic oil via a hydraulic pump that is also mounted on the engine shaft in the diesel engine according to the preamble. Yes (see Patent Document 4). There has already been disclosed a cooler for cooling the recirculated exhaust gas. However, the output of the hydraulic pump taken out by the engine shaft still reduces the overall efficiency of the diesel engine.

  Another example of a two-cycle large diesel engine that recirculates exhaust gas or combustion gas can be read from US Pat. Again, the recirculation gas compressor, i.e. the recirculation pipe, compresses the recirculated exhaust gas partial flow to the scavenging gas high pressure side, i.e. the scavenging air pressure or supply air pressure prevailing on the downstream side of the turbo compressor in the intake path A compressor disposed in the road is provided. The motorized auxiliary drive of the compressor located in the recirculation line is supported by a turbine that, together with the recirculation gas compressor, forms a low pressure turbocharger. This recirculation turbine is also driven by a partial charge air flow that branches off from the supply air downstream of the turbocharger supply air compressor, that is, a turbocharged air partial flow. This supply air partial flow is relaxed when the recirculation turbine is driven and must be led to the exhaust path without contributing to combustion chamber supercharging. In other words, the total efficiency of the internal combustion engine is reduced here by the output used to supercharge the supply air partial flow required to drive the recirculation turbine, and only by the output consumed by the electric auxiliary drive. descend.

German Patent Invention No. 10 2009 010 808 Specification German Patent Application Publication No. 10 2007 052 118 International Publication No.94 / 29587 Pamphlet US Patent Application Publication No. 2009/0173071 German Patent Invention No. 103 31 187 Specification

  Given that, the object of the present invention is to further increase the overall efficiency in an internal combustion engine of the type pointed out at the beginning.

  According to the invention, a diesel engine, in particular a two-cycle large diesel engine, has a steam turbine connected to the recirculation gas compressor without a transmission for driving the recirculation gas compressor.

  This advantageously allows the heat loss always generated in the internal combustion engine to be used to operate the recirculation gas compressor. This can save, for example, about 2% of the diesel engine power that must be added to operate the recirculating gas compressor in a large two-cycle marine diesel engine of the type described in the preamble.

  Particularly suitable for extracting heat loss for steam generation is the exhaust gas stream coming from the combustion chamber. Therefore, advantageously a steam generator is provided which is operated on at least part of the internal combustion engine exhaust gas.

  For example, the steam generator could be circulated from the exhaust gas line on the low pressure side of the exhaust air-turbocharger stage of the internal combustion engine. This exhaust gas line is connected via a working fluid line to a steam turbine connected to a recirculation gas compressor.

  The invention can be used in particular in an internal combustion engine of the kind according to the preamble that recirculates exhaust gas on the high-pressure side of the charge air-turbocharger or turbocharger stage.

  Particularly advantageous in such systems is when a steam generator is provided upstream of the steam turbine in the recirculation line. On the other hand, the heat energy contained in the recirculated exhaust gas has not been used in the past. On the other hand, it may even be desirable to cool the recirculated exhaust gas, thereby providing a boost. In other words, by extracting heat from the recirculated exhaust gas, not only is the drive energy for the recirculated gas compressor obtained from a source that has not been used in the past, but also the desired cooling of the recirculated exhaust gas is achieved.

  The steam generator can be formed as a heat exchanger that extracts heat from the recirculated exhaust gas to heat and evaporate the working medium, usually water, and in some cases overheat.

  Since there is enough heat energy in the recirculated exhaust gas partial flow to drive the steam turbine of the recirculation gas compressor, the steam generator also uses the steam turbine to drive the recirculation gas compressor. In addition, the rotational speed control unit for the steam turbine can be formed relatively simply. Mainly, the recirculation gas compressor is connected to a steam turbine without a transmission and integrated into a steam turbo set. In that case, the steam turbine must be designed in a large two-cycle large diesel engine so that the recirculation gas compressor speed range is, for example, about 7000-15000 rpm and matches the steam turbine speed range. Between the force required by the recirculation gas compressor or the steam turbine coupled thereto and the steam force generated by the steam generator provided upstream in the recirculation line and acting on the steam turbine. The steam turbo set can be kept without a transmission because the one-to-one relationship is established.

  In this case, a steam throttle valve is advantageously arranged exclusively in the pressure line from the steam generator to the steam turbine in order to control the rotational speed of the steam turbine. This steam valve or throttle valve or steam throttle valve is sufficient as a rotational speed control unit for the steam turbine. In that case, in the simplest case, no other control element is required when the diameter reduction of the uncontrolled steam throttle valve is preferably chosen here. However, the steam throttle valve can also be adjustable so that the steam throttle valve can be readjusted or displaced manually by an operator or via a suitable drive. However, in this case as well, the rotational speed control of the steam turbine can be performed only through a non-controlled steam throttle valve or only through a steam throttle valve that can be set by an operator.

  Because of the one-to-one relationship described above, an uncontrolled steam throttle valve or a steam throttle valve that can be set by an operator is often sufficient, and the control of the steam turbine speed can be limited to a particularly simple one. .

  However, it is also conceivable that the configurable steam throttle valve functions as an actuator in an open loop control circuit or a closed loop control circuit. Even in such a case, a control unit or measuring element and control element for the steam throttle valve must still be provided. In this case, however, the rotation speed of the steam turbine is controlled only via a steam throttle valve arranged in the pressure line from the steam generator to the steam turbine, for example from a pressure sensor arranged at the end of the recirculation line. In response to the pressure sensor signal. Of course, if the pressure lines are in parallel between the steam generator and the steam turbine, it would be conceivable to connect a plurality of steam throttle valves in each pressure line or simply several pressure lines in parallel.

  In terms of simple structure and easy control, a unique single steam turbine not connected to the other output is advantageously provided for driving the recirculation gas compressor, For this reason, no other parallel driving unit is provided. It may be advantageous to have just one small electric auxiliary drive that speeds up the recirculation gas compressor during the start-up phase of the internal combustion engine, this auxiliary drive being possibly connectable to the shaft of the steam turboset .

  However, additional steam loads that can be connected to the steam turbine, such as generators, or additional steam loads that can be charged with excess steam to make excess steam energy available for additional power generation, such as generators. A set could be considered. Similarly, part of the generated steam is exposed to corrosive action by harmful substance particles contained in the recirculated exhaust gas through the soot blower in the steam generator or in the downstream pipe part of the recirculation pipe. It would be possible to inject into the recirculation line side surface.

  A steam turbine can have a geometry that is very simple and therefore inexpensive to make, for example, it simply comprises one or two impellers or impellers. This is because sufficient steam energy is available for driving the steam turbine in the steam generator in the recirculation line and therefore no great optimization is required. The steam generator can still be kept relatively small since only a few planes are required to provide the steam energy required to drive the steam turbine.

  The steam “consumed” in the recirculating gas compressor-steam turbine can simply be released to the environment when enough fresh water is available for steam generation, eg sea water on the ship. However, in order to avoid contamination of the working fluid line, it is often necessary to use a working fluid that is not sufficiently available, for example fresh water with a low salt content, so that it is within the framework of the thermodynamic cycle process. In other words, it is advantageous to carry out steam generation and consumption of steam energy in a closed system without working fluid or with only a small loss of working fluid. Therefore, a working fluid line leads from the steam turbine to a condenser provided downstream at the point of flow, in which the working fluid is liquefied and fed from there to a feed pump, Advantageously, a steam generator, which is connected via a line with a feed pump, is fed from this feed pump.

  More efficient use of the heat contained in the exhaust gas for other purposes, for example for additional power generation or to improve the supercharging of the engine combustion chamber via an additional steam-operated charge air compressor If so, more efficient but more efficient parts can of course be used. The steam generator can then have, for example, a tube bundle guided by a recirculation line, which forms part of the working fluid line, and the reflux exhaust gas flows around the tube bundle. The tubes of the tube bundle can be mounted spirally in the exhaust gas path. A multi-stage steam generator with an evaporator and a downstream superheater stage could be considered, but is not necessarily required to only operate a steam turbine connected to a recirculation gas compressor.

  Additional gas scrubbers in the recirculation path can cause scrubbing and sulfur scavenging removal from the recirculated exhaust gas, thereby reducing the toxic substance emissions of the internal combustion engine. Particularly suitable here is the steam generated by the steam turbine as proposed, in particular by the steam generated by the steam generator arranged in the recirculation line, and therefore by the steam generated by the reflux exhaust gas itself. The recirculation gas compressor is driven. In other words, the gas scrubber further reduces the gas pressure in the recirculated exhaust gas, and the recirculation gas compressor must be implemented correspondingly with higher performance, but also with more performance hunger, thus saving The potential of is reasonably high.

  If a steam generator is arranged in the recirculation line, a gas scrubber is placed in the middle of the flow with respect to the steam generator for cooling the recirculated exhaust gas partial flow and the recirculation gas compressor, i.e. It is also advantageous if it is downstream of the steam generator. This is because in that case the gas scrubber is considerably smaller and therefore cheaper at the same pressure drop in the recirculated exhaust gas partial flow compared to the gas scrubber without pre-cooling in the steam generator. This is because it can be designed. In doing so, what has already been said in advance about the steam turbine, the steam generator and the control part of the steam turbine rotational speed apply. The expected pressure loss can be easily compensated based on the sufficient existing energy available to drive the recirculation gas compressor by the steam generator in the recirculation line, so the gas scrubber is comparative It can be made small and simple.

  If a cooling mechanism or cooler, for example a heat transfer heat exchanger operating with liquid water as the cooling medium, is additionally provided in the recirculation line, the temperature of the reflux exhaust gas can be further reduced. And a more advantageous degree of filling can be obtained on the basis of a high exhaust gas density at low temperatures and thus a small volume flow. If the cooler is placed intermediate to the steam generator and the exhaust scrubber in terms of flow, the exhaust gas can be cooled in the scrubber to such an extent that synthetic resin parts or plastic parts can be used. This can significantly reduce production costs and weight, and can result in surfaces that do not corrode or only corrode in the gas scrubber.

  At the same time, the cooler can be used as a preheater for the working fluid supplied in liquid form to the steam generator, ie generally liquid water. In other words, the working fluid can be preheated by a cooling medium warmed in the cooler, or can itself be used as a cooling medium.

  Advantageously, as long as a gas scrubber is provided in the recirculation line, the recirculation gas compressor is used to separate the water particles present in the exhaust gas before reaching the compressor based on gas scrubbing. A droplet separator is provided on the upstream side. In that case, the water droplets can be separated from the volume stream flowing through the recirculation line at the outlet side droplet separator and discharged through a suitable condensate outlet. This results in a further reduction of the volume flow that should be increased to the prevailing pressure level in the suction path at the inlet to the suction path. Demonstrated as droplet separators are turning plates, packings, strainers and perforated bottoms that can be made of plastic due to exhaust gas cooling.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of an internal combustion engine according to an embodiment of the present invention.

  The main field of application of the present invention is large engines, in particular two-cycle large diesel engines, which can be used as ship drives or for power plants. Such engine structures and modes of operation are known per se.

  The two-cycle large diesel engine schematically shown in FIG. 1 can have a series of cylinders Z. Each cylinder Z defines a combustion chamber B with a cooperating piston K. Exhaust valves A are provided at the upper ends of the combustion chambers B, and exhaust gas generated during combustion is discharged into the exhaust gas collecting container 15 through the exhaust valves. From there, the exhaust gas reaches the turbine 18 of the turbocharger 1 through a single (or multiple) exhaust line 23.

  However, a part of the exhaust gas is recirculated in the illustrated example from the recirculation line 15 branched from the exhaust gas collecting container 15, but in some cases from the recirculation line 3 also branched from the exhaust line 12, to the intake side of the internal combustion engine, or It is recirculated into the suction paths 11, 13 and 14. The recirculation line 3 can also be branched from the exhaust passages 12, 15 already upstream of the exhaust gas collection vessel 15 or already through a unique outlet of the combustion chamber B.

  The intake passages 11, 13, 14 have a compressor 19 of the charge air-turbosupercharger 1 on the inlet side, which is connected to the turbine 18 in order to increase the supplied charge air to a high pressure level. It is driven via the exhaust gas passed through. From this compressor 19, a supply air line 11 is connected to a supply air collection container 14 or a supply air collection line 14 via a selective supply cooler 13, and from the latter, individual combustion chambers (single / multiple) B gets fresh. The exhaust gas recirculation line 3 is poured into the supply air line 11 in front of the supply air accumulator 14 and, in particular, sufficient cooling either upstream of the supply air cooler 13 or in the recirculation line 3 Pour on either of the downstream sides of the charge air cooler.

  The recirculation line 3 is passed on the inlet side to a steam generator 5 formed as a heat exchanger, and on the opposite side of the closed cycle system, the working fluid line 4 is passed to this steam generator, The liquid working fluid to be evaporated in the steam generator 5 is supplied to the steam generator 5 through this working fluid line. On the downstream side of the steam generator 5, the steam turbine 8 is coupled to the steam generator 5 via the pressure line portion of the working fluid line 4, and is driven by the steam pressure acquired in the steam generator 5, It drives the recirculation gas compressor 10 itself. This recirculation gas compressor is at the outlet end of the recirculation line 3 downstream of the steam generator 5 and raises the recirculated exhaust gas to the prevailing pressure level in the supply air line 11.

  The water-steam cycle formed by the working fluid line 4 has a condenser 9 downstream of the steam turbine 8, and the steam-like working fluid relaxed in the steam turbine 8 is condensed in this condenser and then supplied The steam is supplied again to the steam generator 5 by the pump 16. A supply container can be placed intermediately between the condenser 9 and the supply pump 16, and the condensed working fluid is collected in this supply container.

  The magnetic turbine 8 and the recirculation gas compressor 10 are coupled to each other via a common shaft without a transmission to transmit torque and form the steam turbo sets 8 and 10. The rotational speed of the steam turbine 8 is set via a throttle 17 or a steam throttle valve 17 in the pressure line portion of the working fluid line 4 between the steam generator 5 and the turbine 8.

  The recirculation line is first passed through the gas treatment device in the region between the inlet side steam generator 5 and the outlet side compressor or blower 10, which is connected to the heat transfer heat exchanger 6 and its downstream side. A gas cleaning device 7 is provided on the side. The gas treatment device can further comprise an inlet-side pre-injection mechanism, i.e. one or more nozzles provided in the recirculation line 3, for example, which are charged with cooling water coming from the water inlet. Is injected into the recirculation line 3, thereby generating a humid environment in the recirculation line 3, particularly in a region of the recirculation line 3 disposed downstream of the pre-injection mechanism. This moist environment is passed through the heat transfer heat exchanger 6 to be cooled. In that case, the prevailing wet environment on the exhaust gas side of the heat transfer type heat exchanger 6 forms a liquid corrosion prevention layer on the wall of the heat exchanger 6 against the adhesion of soot or the chemical action of sulfur particles contained in the exhaust gas. . The gas scrubber 7 is advantageously below the heat transfer heat exchanger 6, the coolant injected into the recirculation line 3 in the pre-injection mechanism and flowing through the heat exchanger 6, and the heat exchanger 6. The liquid condensed from the exhaust gas stream due to cooling inside flows into the gas scrubber 7. The water vapor is cooled in the heat exchanger 6 and combined with this, the water vapor that is always contained in the exhaust gas (the exhaust gas of a large diesel engine contains up to 25% by mass of water) condenses, so Cleaning is performed.

  Cold liquid water flowing through the heat transfer heat exchanger 6 on the coolant side can be suitably prepared in most cases and has a high heat transfer capacity. If an internal combustion engine is used in a ship, it may be considered that the heat exchanger 6 is charged with seawater. Further, as shown by the broken line in the figure, the heat transfer heat exchanger 6 is operated with the working fluid of the water-steam cycle as a cooling medium, so that the working fluid is supplied to the steam generator 5 before being supplied to the steam generator 5. It would be possible to preheat

  Selectively downstream of the gas scrubber in recirculation line 3 to separate the water droplets still contained in the cold exhaust gas stream and thus further dry the exhaust gas stream and subject it to final cleaning. For example, various turning plates or appropriate fillers can be provided in the droplet separator arrangement, that is, the exhaust gas flow path. A liquid outlet can also be provided there.

  The dried and purified cold exhaust gas stream is now fed to the compressor 10. This compressor is at the end of the recirculation line 3 and is itself driven via the steam generated in the steam generator 5 or the steam turbine 8 operated with this steam.

  The steam generator 5 can be formed as a pipe part of the recirculation pipe 3, and this pipe part is passed through a pipe part formed as a steam boiler in the working fluid pipe. Since the difference between the temperature of the working fluid supplied in liquid form to the steam generator 5 and the temperature of the recirculated exhaust gas is large, the surface available for convective heat transfer can be kept relatively small. 5 can simply be formed in the form of a double-walled tube, in which the exhaust gas flows around the working fluid to be evaporated or vice versa.

  Changes and modifications to the illustrated embodiments are possible without departing from the scope of the invention.

  Steam generator in two or multiple stages, with one evaporator formed as a shell and tube heat exchanger and one or more superheater stages formed as a shell and tube heat exchanger In order to take advantage of the steam power that is designed and utilized not in the recirculating gas compressor-turbo set, it would be conceivable to provide other pressure lines leading to another steam load that can be selectively charged.

  Instead of or in addition to the steam generator 5 located in the recirculation line, it provides fully or partly the steam pressure required to operate the recirculation gas compressor-steam turbine 8 Therefore, as suggested by a broken line in the figure, another steam generator 5a can be provided on the downstream side of the turbine 18 of the supply air-turbosupercharger 1 in the exhaust path.

Claims (10)

A two-cycle large diesel engine,
It has at least one combustion chamber (B) limited by a cylinder (Z) and a piston (K) that cooperates with the crankshaft. The combustion chamber is mainly attached to the valve head of the exhaust valve (A). And at least one outlet formed between the head and the exhaust passage for discharging exhaust gas into the exhaust passage (12, 15), and the intake passage (11, 13, 14) mainly controllable by the piston (K) And at least one inlet for supplying scavenging gas from
At least one turbocharger (1) having a compressor (19) in the suction path (11, 13, 14) and a turbine (18) in the exhaust path (12, 15);
Branches from the exhaust path (12, 15) or the combustion chamber (B) to the intake path (11, 13, 14) to recirculate the exhaust gas partial flow to the intake path (11, 13, 14) A recirculation line (3) for allowing at least one recirculation in the recirculation line to push the recirculated exhaust gas partial flow into the scavenging gas flow in the suction path (11, 13, 14) In what is provided with a gas compressor (10),
In order to drive the recirculation gas compressor (10), a steam turbine (8) connected to the recirculation gas compressor (10) and transmitting torque is provided, that is, the recirculation gas compressor. (10) and a steam turbine (8) forming a steam turbo set (8, 10) without a transmission is provided,
In order to evaporate the working fluid, a steam generator (5; 5a) is provided which is operated with at least part of the exhaust gas of a two-cycle large diesel engine and is connected to the recirculation gas compressor (10). The working fluid line (4) for supplying steam to the steam turbine (8) includes at least one pressure line (4) from the steam generator (5) to the steam turbine (8). ,
A heat exchanger (5) operated with a recirculated exhaust gas partial flow is provided upstream of the steam turbine (8) in the recirculation line (3) as the steam generator (5) ,
The working fluid line (4) leads from the steam turbine (8) to a condenser (9) provided downstream in terms of flow, and the working fluid is liquefied in the condenser (9), From there, it is supplied to the supply pump (16) and supplied to the steam generator (5) connected to the supply pump (16) via the working fluid line (4) by the supply pump (16). This is a two-cycle large diesel engine.   The working fluid line (4) is formed in the region of the steam generator (5) as a pipe or tube bundle part guided by an exhaust gas line, and / or the working fluid line (4) 2. A two-cycle large diesel engine according to claim 1, characterized in that it is formed as a steam boiler part surrounding the exhaust gas passage in the region of the steam generator (5).   A steam throttle valve (17) is provided in the pressure line (4) from the steam generator (5) to the steam turbine (8) to control the rotation speed of the steam turbine. The two-cycle large diesel engine according to claim 1 or 2, characterized in that Prior claim, characterized in that the steam generator is formed in a multi-stage manner with one first heat exchanger part serving as an evaporator and at least one second heat exchanger part serving as a superheater. Item 2. The two-cycle large diesel engine according to any one of items 1 to 3 . The steam generator is coupled to other steam loads that can be selectively applied via a pressure line portion that can be shut off and / or connected to the steam turbine to transmit torque The two-cycle large-sized diesel engine according to any one of claims 1 to 4 , wherein a steam load is provided. 2-stroke large diesel engine according to any one of the preceding claims 1-5, characterized in that it comprises the steam turbine (8) is merely one or two impellers stages. 2-stroke large diesel engine start-up phase the recycle gas compressor in (10) of any one of claims the preceding claims 1-6, characterized in that the electric starter auxiliary drive unit for actuating is provided 2-cycle large diesel engine. The recirculation line (3) is passed through a gas scrubber (7) disposed mainly downstream of the steam generator (5) and upstream of the recirculation gas compressor (10). preceding claims 1 to 7 any one two-stroke large diesel engine according to according to claim. The recirculation pipe (3) is passed through a cooling mechanism (6), and the cooling mechanism is located downstream of the steam generator (5) and upstream of the recirculation gas compressor (10). The two-cycle large-sized diesel engine according to any one of claims 1 to 8 , wherein the two-cycle large-scale diesel engine is disposed upstream of (7), and the cooling mechanism includes a heat transfer heat exchanger (6). . The working fluid line (4) is passed through the cooling mechanism (6) in a region upstream of the steam generator (8), and the working fluid is preheated by the cooling medium or uses itself as the cooling medium. The two-cycle large diesel engine according to claim 9 .