KR20130126505A - Internal combustion engine - Google Patents

Abstract

The present invention relates to a large two-stroke diesel engine with at least one combustion chamber (B) limited by a piston (K) which interlocks with a cylinder (Z) and a crank shaft. An engine comprises one or more turbochargers (1) which comprise compressors (19) in suction areas (11, 13, 14) and turbines (18) in exhaust areas (12, 15); a re-circulation line (3) with one or more re-circulation gas compressors (10), which re-circulate exhaust gas to the suction areas (11, 13, 14). The re-circulation lines branch from the combustion chamber (B) or exhaust areas (12, 15), and are connected to the suction areas in order to guide re-circulated gas to the suction areas (11, 13, 14). The invention comprises a steam turbine (8) which is connected to the gas compressors (10) and makes steam turbo sets (8, 10) without transmissions but with the gas compressors (10) in order to deliver torque for operating the re-circulation gas compressors (10).

Description

Internal combustion engine {INTERNAL COMBUSTION ENGINE}

The present invention relates to a large two-stroke diesel engine comprising turbocharge and exhaust gas recirculation according to the preamble of claim 1.

Turbocharger stages are generally used to recover energy from the exhaust gases from the engine and consequently to compress the boost air supplied to the engine or to boost the gas supplied to the engine and to improve combustion, especially in the case of large diesel engines. do. In particular, in the case of a multi-cylinder engine, a plurality of turbochargers are also used for this purpose, and the entire turbocharger forms a turbocharger stage.

Like turbocharging, in addition to recovering energy from emissions or measures associated with exhaust gases, today the focus is on clean combustion as much as possible. To this end, part of the exhaust gas is often recycled towards the intake of the engine, so that combustion temperatures and NO _x − emissions of the engine can be reduced in this way.

In this case, since the gas treatment devices are often provided in the recycle line, for example, an exhaust gas scrubber device, sulfur and soot particles contained in the recycled exhaust gas are not desired but cannot be recycled into the combustion chamber, in which case the exhaust gas recycle This may lead to a reduction in engine NO _x emissions, but may instead lead to an increase in sulfur load during exhaust gas emissions. A gas scrubber device is therefore located in the recirculation line in the case of a diesel engine comprising exhaust gas recirculation as described, for example, in DE 10 2009 010 808 B3 of the applicant.

In the case of perfusion of this type of gas treatment device, the pressure drop occurs in the exhaust gas that is recycled. Even without such a gas treatment, the pressure corresponding to the pressure in the combustion chamber at the time of discharge of the recycled exhaust gas is often not high in the recycled exhaust gas, so that the exhaust gas is directly into the purge air or supercharged air in the intake zone without additional compressors. May be introduced. This is particularly effective if the recycle line is to be connected to the intake zone on the purge gas high pressure side, ie downstream of the boost air-turbocharger or turbocharger stage, where compression of the purge air or boost air to be supplied to the engine takes place. In order to prevent the exhaust gas to be recycled from being supplied through the turbocharger stage's supercharged air compressor (s), the introduction of recycle exhaust gas into the intake zone on the purge gas high pressure side and consequently the recycle from the exhaust zone upstream of the turbine of the turbocharger Branching of the line is preferred, but the overall efficiency of the internal combustion engine may be degraded.

German patent application DE 10 2007 052 118A1 includes exhaust gas recirculation on the high pressure side, ie branching of the recirculation line from the exhaust zone upstream of the turbine of the turbocharger and connecting to the intake zone downstream of the supercharged air-compressor. A turbo compound-car-diesel engine is described. Downstream of the turbine of the turbocharger used for supercharged air compression, other power turbines are incorporated in the exhaust line which are not recycled but rather exhaust gas exhausted to the outside, and the power turbine is controlled by a controllable fluid coupling and transmission. It is connected to the crankshaft. In this case, the recycled exhaust gas is cooled using a heat exchanger installed in the recycle line. These heat exchangers are implemented as steam generators and are used to drive the steam turbines in the exhaust zone downstream of the power turbines, along with other heat exchanger-steam generators correspondingly formed, the power turbines crankshafting the drive output by fluid coupling. Or to an auxiliary unit in the drive train, for example to a generator. With the power turbine, on the one hand, energy not used by the turbocharger of the engine can be recovered from the exhaust gas which is discharged to the outside. However, according to DE 10 2007 052 118A1, by the control of the fluid coupling connecting the power turbine to the crankshaft, additional power turbines are mainly used to control the dynamic pressure falling from the power turbine in the way as an obstacle to the exhaust gases emitted. As a result, it is used to adjust the exhaust gas component recycled relative to the exhaust gas discharged and the pressure of the main, recycled exhaust gas upstream of the turbocharger in the exhaust region. Therefore, the fluid coupling which finally connects the power turbine to the crankshaft is adjusted to raise the recycle exhaust gas to the prevailing pressure level on the high pressure side of the purge gas in the intake region.

In contrast, in the case of large two-stroke diesel engines comprising exhaust gas recirculation on the high pressure side, i.e. branching of the recirculation line from the exhaust zone upstream of the turbine of the turbocharger and connecting to the intake zone downstream of the compressor of the turbocharger. Since a compressor driven by an electric motor is provided in the recirculation line, the recirculated exhaust gas is intaken, for example, as can be seen in the applicant's WO-document WO 94 / 29587A1 (International Application No. PCT / DK93 / 00398). It can be raised to the prevailing pressure level on the high pressure side of the purge gas in the region. There the gas scrubber is located in the recirculation line upstream of the compressor. In this case the electrical output required to drive the compressor in the recirculation line can be applied, for example, in a generator set provided for the operation of the electrical network of the ship driven by the internal combustion engine. However, this reduces the overall efficiency of the internal combustion engine.

According to another proposal, in the case of such a diesel engine, the fan in the recirculation line is driven by a fluid turbine, which in turn is supplied with high pressure hydraulic oil by means of a hydraulic pump installed on the motor shaft, which is US patent application US 2009/0173071 A1. See also. There is also disclosed a cooler for cooling the exhaust gas recycled therein. But the hydraulic pump output tapping on the motor shaft also reduces the overall efficiency of the diesel engine.

Another example of a large two-stroke diesel engine comprising a recycle of exhaust or combustion gases can be found in DE 103 31 187 B4. In this case also, a recirculating gas compressor, i.e., a compressor disposed in the recirculation line, is provided, so that the exhaust gas partial flow to be recycled is compressed to a purge pressure or boost air pressure prevailing on the high pressure side of the purge gas, i.e., downstream of the turbo compressor in the intake zone. Can be. In this case an electric auxiliary drive of the compressor arranged in the recirculation line is supported by the turbine, which together with the recirculating gas compressor forms a low pressure turbocharger. The recycle turbine is again driven by a turbocharged boost air partial flow branched from the turbocharged air downstream of the turbocharger's charge air compressor. This supercharged air partial flow is inevitably expanded and driven into the exhaust zone when the recycle turbine is driven, and no contribution to the combustion chamber supercharge can be made. Therefore, the overall efficiency of the internal combustion engine here falls as much as the power used for the supercharging of the boost air partial flow required to drive the recirculating turbine and the power used for the electric auxiliary drive.

The problem of the present invention which started from this point is to improve the overall efficiency in the internal combustion engine of the kind mentioned above.

According to the present invention, diesel engines, in particular large two-stroke diesel engines, have a steam turbine coupled to a recycle gas compressor without a transmission for driving the recycle gas compressor.

This advantageously allows the loss of heat, which always occurs in the internal combustion engine, to be used in the operation of the recycle gas compressor. Thus, for example, in the case of a large two-stroke marine diesel engine of this kind, about 2% of the diesel engine power that will necessarily be used to drive the recirculating gas compressor is saved.

In this case the exhaust gas stream from the combustion chamber is particularly suitable for tapping of the lost heat for steam generation. It is therefore advantageous to provide a steam generator which operates at least as part of the exhaust gas of the internal combustion engine.

Thus, for example, on the exhaust gas low pressure side of the turbocharger stage of the internal combustion engine, the steam generator may be penetrated by an exhaust gas line, which is connected to a steam turbine coupled to the recirculating gas compressor by a working fluid line. It is.

The invention can be used on the high pressure side of the turbocharger or turbocharger stage, in particular for internal combustion engines and exhaust gas recirculation of this kind.

Particularly advantageous in such a system is that a steam generator in the recirculation line is provided upstream of the steam turbine. This is because the thermal energy contained in the exhaust gas recycled on the one hand has not been used until now. On the other hand, it is desired that good supercharging be achieved as even the recycled exhaust gas is cooled. Thus, through heat recovery from the recycled exhaust gas, not only the drive energy for the recycled gas compressor is recovered from a source that has not been used so far but also further cooling of the recycled exhaust gas is achieved.

In this case, the steam generator can be formed as a heat exchanger in which heat is recovered from the recycled exhaust gas, so that the working medium, normally water, is heated and evaporated and in some cases can be superheated.

Since sufficient heat energy can be recovered to drive the steam turbine of the recycled gas compressor in the recycled exhaust gas partial stream, the steam generator can also be formed relatively relatively in a primitive manner. The same applies to speed control for steam turbines. Advantageously the recirculating gas compressor is coupled to the steam turbine without a transmission and constitutes a steam turbo set. In such a case, the steam turbine should be designed such that the speed range of the recirculating gas compressor corresponds to the speed range of the steam turbine, for example about 7000-15000 rpm / min for large two-stroke diesel engines. Therefore, in this case, there may be no transmission in the steam turbo set, in which there is a difference between the force required by the recirculating gas compressor or the steam turbine connected to it and the steam force generated by the steam generator connected upstream in the recirculation line and applied to the steam turbine. 1 relationship exists.

In this case advantageously only steam throttle valves are provided which are arranged in a pressure pipe from the steam generator to the steam turbine for control of the steam turbine speed. Such a steam valve or throttle valve or steam throttle valve is sufficient as a speed control device for the steam turbine. In the simplest case, if the diameter shrinkage is properly selected in an uncontrolled steam throttle valve, other control elements are unnecessary. However, since the steam throttle valve can be adjusted, the steam throttle valve can be readjusted or adjusted by hand by an operator or by a suitable drive. However, even in this case, the speed control of the steam turbine may be achieved only by an uncontrolled steam throttle valve or by an operator adjustable steam throttle valve.

Because of the 1: 1 relationship described above, in many cases an uncontrolled steam throttle valve or an operator adjustable steam throttle valve is sufficient, so that control of the steam turbine speed can be maintained particularly easily.

However, it would also be conceivable to operate the adjustable steam throttle valve as an adjustment member in an open or closed control circuit, in which case a control or measuring member and a control member for the steam throttle valve should be provided. However, even in this case, the control of the steam turbine speed can only be achieved by a steam throttle valve placed in the pressure pipe from the steam generator to the steam turbine, ie during the response to pressure sensor signals from the pressure sensor placed at the end of the recirculation line. Is done. Of course, in the case of parallel pressure pipes between the steam generator and the steam turbine, one can also consider a plurality of parallel connected steam throttle valves in all or only a few of the pressure pipes.

In this case, a steam turbine is advantageously provided for the operation of the recirculating gas compressor, which is not connected to any of its outputs, in addition to its simple structure and easy control, as well as other parallel drives for the recirculating gas compressor. It is not. Only a small electric auxiliary drive for the run-up of the recirculating gas compressor during the starting phase of the internal combustion engine may be usefully provided, which in some cases may be coupled to the shaft of the steam turbo set.

However, it may be conceivable to provide an additional output, for example a generator that can be connected to a steam turbine, or an additional steam consuming device, for example a generator set that can be supplied with surplus steam, surplus steam energy for the production of additional current. May be used. Spraying a portion of the steam generated by a sootblower on the surface of the recirculation line, exposed to corrosion from harmful particles in the exhaust gas that is recycled in the steam generator or in line regions located downstream of the recirculation line. You might think about doing it.

The steam turbine can have a structure that is very simple and consequently economically manufacturable, for example having a structure comprising one or two blade wheels or impellers, the steam being driven by the steam generator in the recirculation line. This is because sufficient energy is supplied and as a result high levels of optimization are unnecessary. The steam generator can again be kept relatively small since only a small surface is needed to provide the steam energy required to drive the steam turbine.

The steam "consumed" in the recirculating gas compressor-steam turbine can easily be discharged to the outside once clean water is sufficiently prepared for steam production, for example when seawater in a ship is ready. In order to avoid impurities in the working fluid line, a working fluid that is often not provided sufficiently, for example, needs to be used for fresh water free of high salinity, so that in the range of thermodynamic cycles, i.e. without or with little loss in the working fluid, It is advantageous to carry out steam generation and consumption of steam energy in a closed system. Therefore, the working fluid line leads from the steam turbine to the condenser where the working fluid is liquefied, downstream from the flow point of view, from which the steam generator, which is connected to the supply pump by the working fluid line, leads to the supply pump receiving the working fluid. It is advantageous.

If the heat contained in the exhaust gas is more effective for other purposes, for example for the production of additional current or for the supercharging of engine combustion chambers by an additional steam driven turbocharger, expensive but effective elements may of course be used. Can be. In such a case the steam generator may have a tube bundle, for example, connected to a recirculation line, which forms a region of the working fluid line and the exhaust gases that are recycled flow around this tube group. In this case, the pipes of the group can be suspended in a spiral in the exhaust gas path. Multistage steam generators, including evaporators and superheater stages downstream thereof, are also conceivable, but are not necessary for the operation of a steam turbine coupled to a recycle gas compressor.

The cleaning of soot and sulfur from the exhaust gas recycled through an additional gas scrubber device in the recirculation zone can be achieved, thereby reducing the emission of harmful substances in the internal combustion engine. The proposed operation of the recycle gas compressor by a steam turbine is particularly suitable, in particular when using steam produced by a steam generator arranged in the recycle line and by the exhaust gas itself being recycled. As the gas scrubber causes the gas pressure to drop in the recirculated exhaust, the recirculating gas compressor must be correspondingly more powerful but more power hungry and consequently savings potential is correspondingly. high.

The best configuration when a steam generator is placed in the recirculation line is disposed between the steam generator and the recirculating gas compressor that cools the exhaust gas partial stream where the gas scrubber is recycled from a flow point of view, ie located downstream of the steam generator. . Such gas scrubbers are much smaller and therefore more economical than scrubbers that are not precooled, even at the same pressure drop in the recycled exhaust gas partial flow. In this case, the foregoing is valid for steam turbines, steam generators, and steam turbine speed control devices. The gas scrubber device can have a relatively small and simple structure, since the expected pressure loss can be easily compensated for because of the abundant energy available by the steam generator in the recycle line for driving the recycle gas compressor.

If an additional cooler or cooler is provided in the recirculation line, for example a recuperation-heat exchanger operating as liquid water as the cooling medium, the temperature of the exhaust gas to be recycled The degree of filling is much more favorable because of the higher density at lower temperatures and the smaller flow rate of the exhaust gas at lower temperatures. If a cooler is placed between the steam generator and the exhaust scrubber device from a flow standpoint, the exhaust gas cooling can be made to the extent possible in the gas scrubber as the use of plastic parts reduces manufacturing costs and weight significantly and does not corrode or only weakly. Corroded surfaces may be provided.

The cooler may in this case also be used as a preheater for the working fluid, ie generally liquid water, which is supplied in the liquid phase to the steam generator at the same time. In other words, the working fluid can be preheated through the heated cooling medium in the cooler or can be used directly as the cooling medium.

As long as the gas scrubber device is in the recycle line, it is advantageous for the droplet separator to be disposed upstream of the recycle gas compressor, so that the droplets that existed in the exhaust gas due to the gas scrubber may be separated before reaching the compressor. In such a case, the droplets can be separated from the flow through the recycle line in the outlet droplet separator and discharged through the appropriate condensate outlet. Therefore, the flow rate to be increased to the prevailing pressure level in the intake area at the connection with the intake area is further subdivided. Baffle plates, fillers, sieves, and perforated plates have been proven as droplet separators, which can also be made of plastic because of the exhaust gas cooling.

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

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 invention is large engines, in particular large two-stroke diesel engines, for example such large engines can be used as ship drive devices or find use in power plants. The structure and method of operation of such engines are known.

The large two-stroke diesel engine shown in FIG. 1 may have a tandem cylinder (Z). Each of the cylinders Z limits the combustion chamber B with the piston K interacting with it. An exhaust valve A is provided at the upper end of the combustion chamber B, respectively, and exhaust gas generated at the time of combustion is discharged into the exhaust gas recovery container 15 through the exhaust valve. From there the exhaust gas reaches the turbine 18 of the turbocharger 1 via one (or plural) exhaust lines 12.

However, some of the exhaust gases diverge from the exhaust gas recovery vessel 15 in the illustrated example, but possibly also from the exhaust line 12, from the recycle line 3 towards the intake of the internal combustion engine or from the intake regions 11, 13, 14) Recycled in. The recirculation line 3 may branch upstream of the exhaust gas recovery vessel 15 of the exhaust regions 12, 15 or may branch through its own exhaust port in the combustion chamber B.

The intake zones 11, 13, 14 have a compressor 19 of the boost air-turbocharger 1 on the inlet side, and the compressor is transported through the turbine 18 to raise the supplied boost air to an elevated pressure level. Driven by the exhaust gas. The charge air line 11 from this compressor 19 is led to the charge air recovery vessel 14 or the charge air recovery line 14 by an optional boost air cooler 13, and the individual combustion chamber (s) B are Receive fresh air from the charge air return line. The exhaust gas recirculation line 3 is connected to the boost air line 11 before the charge air storage vessel 14, more precisely for reasons of sufficient cooling upstream of the charge air cooler 13 or in the recirculation line 3. It is connected downstream of the supercharged air cooler 13.

In this case the recirculation line 3 is connected to a steam generator 5 formed as a heat exchanger at the inlet side, the working fluid line 4 is connected to the steam generator on the opposite side in a closed circuit system, and the steam generator 5 The liquid working fluid which evaporates inside is supplied to the steam generator 5 by the working fluid line. Downstream of the steam generator 5, the steam turbine 8 is connected to the steam generator 5 by the pressure line region of the working fluid line 4, which uses the steam pressure recovered within the steam generator 5. Driven and driving a recirculated gas compressor 10, which is located downstream of the steam generator 5 at the outlet end of the recirculation line 3 and raises the recirculated exhaust gas to the prevailing pressure level in the supercharged air line 11. .

The water-steam cycle formed by the working fluid line 4 has a condenser 9 downstream of the steam turbine 8, in which working fluid in the form of expanded steam in the steam turbine 8 condenses in the condenser and is then supplied. The pump 16 is fed back to the steam generator. In this case, a supply vessel in which the condensed working fluid is recovered can be arranged between the condenser 9 and the feed pump 16.

In this case, the steam turbine 8 and the recirculating gas compressor 10 are connected to each other by a common shaft without a gear so as to transfer torque to form a set of steam turbines 8, 10. In this case the speed of the steam turbine 8 is regulated by a throttle 17 or a steam throttle valve 17 in the pressure line region of the working fluid line 4 between the steam generator 5 and the turbine 8.

The recirculation line is first connected with the gas treatment device in the region between the inlet steam generator 5 and the outlet compressor 10 or blower, the gas treatment device being a return-heat exchanger 6 and a gas scrubber downstream thereof. Has (7). In addition, the gas treatment apparatus may have approximately one or a plurality of nozzles provided in the recirculation line 3, receiving a pilot injection device, that is, cooling water from an intake port, on the inlet side and spraying the recirculation line 3 to the wet environment. In this recirculation line 3, in particular in the region arranged downstream of the pilot injection device of the recirculation line 3, which is connected to the recovery-heat exchanger 6 and consequently cooled, can be provided. In such a case, the wet environment prevailing on the exhaust side of the recovery-heat exchanger (6) is a liquid corrosion resistant at the walls of the heat exchanger (6) to prevent soot adhesion or to prevent chemical erosion of the sulfur particles in the exhaust gas. A protective layer is formed. In this case advantageously the gas scrubber device 7 is located below the return-heat exchanger 6, so that the coolant injected into the recirculation line 3 in the pilot injection device and through the heat exchanger 6 and then heat exchanges. Liquid condensed from the exhaust gas stream through cooling in the vessel 6 enters the gas scrubber 7. In this case, the cooling of the heat exchanger 6 and the condensation of the exhaust gas by condensation of water vapor which is always contained in the exhaust gas (in the case of large diesel engines, the exhaust gas contains up to 25% (mass) water) 1 Preliminary cleaning is performed.

Cold liquid water passes through the recovery-heat exchanger 6 on the refrigerant side, and this water can be provided well in most cases and has a high heat transfer capacity. If such an internal combustion engine is used in a vessel, it may be considered to supply seawater to the heat exchanger 6. In addition, one may consider preheating the cooling medium before it is supplied to the steam generator by operating a recovery-heat exchanger 6 comprising a working fluid of a water-steam cycle as the cooling medium, as indicated by the dotted line in the figure. There will be.

Optionally downstream of the gas scrubber device in the recirculation line 3 an additional droplet separator assembly, ie various baffle plates or corresponding fillers can be provided, for example, in the middle of the exhaust gas flow, so that cold exhaust gas flow The droplets still in it can be separated, resulting in a drying of the exhaust gas stream and a final cleaning. It may be provided with a liquid outlet.

A cold, dry and purified exhaust gas stream is now supplied to the compressor 10, which is located at the end of the recirculation line 3 and driven by steam produced in the steam generator 5 or a steam turbine 8 operated on it. .

The steam generator 5 can in this case be formed as a line region of the recirculation line 3, which is connected to the line region of the working fluid line, which is formed as a steam boiler. In this case, since the surface provided for convective heat transfer may be relatively small due to the large temperature difference between the working fluid supplied in the liquid phase to the steam generator 5 and the recycled exhaust gas, it may be easily formed in the form of a double wall pipe. In the steam generator 5 exhaust gas flows around the working fluid to be evaporated or vice versa.

Modifications and variations of the illustrated embodiments are possible without departing from the scope of the present invention.

Design a steam generator in two or multiple stages, including an evaporator formed as a tube bundle heat exchanger and one or a plurality of superheater stages formed as a tube bundle heat exchanger and required in a recycle gas compressor-turbo set. It may be conceivable to provide other steam consumption devices that can be connected to the choice of pressure lines to take advantage of the steam forces that are not.

In addition or as an alternative to the steam generator 5 arranged in the recirculation line, another steam generator is provided to supply all or part of the steam pressure necessary for the operation of the recycle gas compressor-steam turbine 8, as indicated by the dashed line in the figure. 5a may be provided downstream of the turbine 18 of the turbocharger 1 in the exhaust region.

Claims (13)

At least one combustion chamber B defined by the cylinder Z and the piston K interacting with the crankshaft, the combustion chamber preferably formed between the valve disc of the exhaust valve A and the valve seat assigned thereto, One or more exhaust ports for discharging the exhaust gases into the exhaust zones 12, 15 and one or more intake ports for supplying purge gas from the intake zones 11, 13, 14, which can be controlled by the piston K, Has,
One or more turbochargers 1 comprising a compressor 19 in the intake zones 11, 13, 14 and a turbine 18 in the exhaust zones 12, 15 and
As a recirculation line 3 which recirculates the exhaust gas partial flow into the intake zones 11, 13, 14, branching out of the exhaust zones 12, 15 or the combustion chamber B and leading to the intake zones 11, 13, 14. One or more recirculating gas compressors 10 are located in the recirculation line, so that a large two-stroke diesel engine comprising the parts pushes the recycled exhaust gas partial flow into the purge gas flow in the intake zones 11, 13, 14. A steam turbine set without a transmission is provided with a steam turbine 8 coupled to the recycle gas compressor 10 to transmit torque for driving the recycle gas compressor 10, ie with the recycle gas compressor 10. A large two-stroke diesel engine, characterized in that a steam turbine (8) forming (8, 10) is provided. A steam generator (5; 5a) is provided, which is operated at least as part of the exhaust gas of a large two-stroke diesel engine so that the working fluid, preferably water, can be evaporated, and the working fluid line (4) A large two-stroke characterized in that steam can be supplied to a steam turbine 8 coupled to the recycle gas compressor 10, including one or more pressure pipes 4 leading from the generator 5 to the steam turbine 8. Diesel engine. 2. A large two according to claim 2, characterized in that a heat exchanger (5) operated with an exhaust gas partial stream recycled as the steam generator (5) is provided upstream of the steam turbine (8) in the recycle line (3). Stroke diesel engine. 4. The working fluid line (4) in the region of the steam generator (5) is formed as a tubing region or a tubing region leading through an exhaust gas path and / or in the region of the steam generator (5). And wherein the working fluid line (4) is formed as a steam boiler area surrounding an exhaust gas path formed as a smoke conduit region or a flue conduit group region. The steam throttle valve (17) according to any one of claims 2 to 4, which is arranged in the pressure pipe (4) from the steam generator (5) to the steam turbine (8), for the control of the steam turbine speed. Large two-stroke diesel engine, characterized in that provided. 6. The working fluid line 4 according to claim 2, which is arranged downstream from the steam turbine 8 to a condenser 9 in which the working fluid is liquefied, which flows therefrom. A large two-stroke diesel engine, characterized by a feed pump (16), wherein the steam generator (5) is connected to the feed pump (16) by means of a working fluid line (4) to receive the working fluid. The steam generator according to any one of claims 2 to 6, wherein the steam generator is formed in multiple stages together with a first heat exchanger region used as an evaporator and a second one or more heat exchanger regions used as a superheater. Large two-stroke diesel engine. 8. The method according to claim 2, which is connected to another steam consuming device, for example a generator set, and / or transmits torque, which can be selectively connected by a breakable pressure line branch. A large two-stroke diesel engine, which is provided with another steam consuming device, for example a generator, which can be connected to a steam turbine. The large two-stroke diesel engine according to claim 1, wherein the steam turbine has only one or two impeller stages. 10. The large two-stroke diesel engine according to claim 1, wherein an electric starting auxiliary drive is provided for driving the recirculating gas compressor 10 during the startup phase of the large two-stroke diesel engine. . The recirculation line 3 is connected to a gas scrubber device 7, wherein the gas scrubber device is preferably downstream of the steam generator 5 and of the recycle gas compressor. A large two-stroke diesel engine, disposed upstream of (10). The recirculation line (3) is connected to the cooling device (6), which is in particular downstream of the steam generator (5) and of the recirculating gas compressor (10). A cross-flow radiator 6 is arranged upstream and preferably upstream of the gas scrubber device 7, in which the cooling device is particularly preferably operated with water as cooling medium. A wet bed cooler which is in the form of a) and / or which is wetted with a coolant, consequently having a cold surface, opposing the exhaust gases to be recycled, for example a grid, sheave arranged in a recycle line. Large two-stroke diesel engine, characterized in that in the form of plates, ribs, filler and / or diameter changes (diameter changes). 13. The working fluid line 4 is connected to the cooling device 6 in an area upstream of the steam generator 5, wherein the working fluid is preheated through the cooling medium or used directly as the cooling medium. Large two-stroke diesel engine, characterized in that.

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