The present disclosure generally refers to internal combustion engines and more particularly to charge air systems and cooling systems for internal combustion engines.
Medium speed internal combustion engines comprise a large amount of components. Some of those components are subject to service at, for example, components of cylinder unit such as the pistons. Besides physical wear, various components may further be subject to chemical active substances such as aggressive fuel and exhaust gas.
Internal combustion engines exhaust a complex mixture of air pollutants. These air pollutants are composed of gaseous compounds such as nitrogen oxides (NOX), and solid particulate matter also known as soot. Due to increased environmental awareness, exhaust emission standards have become more stringent, and the amount of NOX and soot emitted to the atmosphere by an engine may be regulated depending on the type of engine, size of engine, and/or class of engine.
In order to ensure compliance with the regulation of NOX, a strategy called exhaust gas recycling (EGR) for mixing the exhaust gas into the charge air may be implemented. EGR may reduce NOX emission. As an exemplary EGR system, the EP application EP 2 218 896 A1 discloses a turbocharged engine with EGR. As another example, the EP application EP 2 333 292 A1 discloses a two-stage turbocharged engine with exhaust gas recycling using a specifically shaped mixing pipe configuration.
In addition to the conventional exhaust gas system, which is inherently subjected to any corrosiveness of the exhaust gas, an EGR system subjects also components of the charge air system to the corrosiveness of the exhaust gas by adding the corrosive exhaust gas to the charge air.
The large dimensions of medium speed internal combustion engines may result in large charge air systems and large exhaust gas systems of similar dimensions as the combustion engine. For example, charge air or exhaust gas pipes may extend along the sides of the internal combustion engines from one turbocharger to the other. Complex structures affect the serviceability of specific components of the engines.
Medium speed internal combustion engines may moreover be adapted for the use with fuels such as diesel fuel, light fuel oil (LFO), heavy fuel oil (HFO), alternative fuels of first generation biofuels (for example, palm oil, canola oil, oils based on animal fat) and second generation biofuels (for example, oils made of non food corps, i.e. waste biomass) that produce an exhaust gas that is destructive, for example, corrosive, to the components with which the exhaust gas gets in contact.
The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.
According to an aspect of the present disclosure, a charge air guide element for an intake manifold of an internal combustion engine with a plurality of cylinder units may comprise a through flow section comprising a first passage fluidly connecting a front side of the charge air guide element with a back side of the charge air guide element and a supply section at a cylinder unit side of the through flow section that comprises a second passage fluidly connecting top side of the charge air guide element with the first passage. The charge air guide element may further comprise, integrated into a wall structure of the charge air guide element, a cooling water channel system that comprises at least one opening at the cylinder unit side of the through flow section, which opens towards the top side of the charge air guide element, and at least one opening at an access side of the charge air guide element, the access side being opposite to the cylinder unit side.
According to another aspect of the present disclosure, a water ring element for being mounted to an engine block of an internal combustion engine may comprise a cylinder liner section with a wall structure surrounding a through hole to provide a passage for a respective cylinder liner in a mounted state of the water ring element, and a cooling system for cooling the cylinder liner in the mounted state of the water ring element, wherein the cooling system may have a conduit structure with at least one opening at an outside of the wall structure that opens towards the engine block side of the water ring element.
According to another aspect, an internal combustion engine may comprise an engine block with a top side, a first end side, and a second end side, the second end side opposing the first end side, a plurality of cylinder units mounted at the top side and having cylinder liners reaching into the engine block, a charge air system comprising an inlet manifold for distributing charge air to each of the plurality of cylinder units, wherein the inlet manifold comprises a plurality of charge air guide elements as described above. The internal combustion engine may further comprise a plurality of water ring elements as described above, each mounted at the top side such that the at least one opening of the cooling system of each water ring element and the at least one opening of the cooling water channel system of the respective charge air element are fluidly connected.
In some embodiments of charge air guide elements, the cooling water channel system may comprises a supply channel and a return channel, each having an opening at the cylinder unit side of the through flow section, which opens essentially in the direction into which the second outlet opening opens.
In some embodiments, charge air guide elements may be one-piece cast parts. In addition or alternatively, water ring elements may be one-piece cast parts.
In some embodiments, a plurality of charge air guide elements may be configured to provide a fluid connection from an exit of a compressor stage to each of the cylinder units.
In general, an inlet manifold external to the engine block may provide good access and may be easy to mount, operate, and replace in comparison to an internal inlet manifold being integrated within the engine block. This applies in particular to an inlet manifold comprised of charge air guide elements.
For example, corrosion caused by exhaust gas supplemented to the charge air may cause damage components of the charge air system such as the charge air guide element of the inlet manifold. An exchange of a damaged component located at the outside may be easily serviced and may not affect the engine block, as, for example, air guide elements and mixing pipes may be formed as separate cast parts that then may be replaced if damaged.
Moreover, a configuration of a water ring element and a charge air guide element as described above may allow demounting the cylinder head and the water ring element for service purposes without the need of demounting the charge air system and the cooling water system.
Positioning of cooling water drainage ports at different positions may further simplify the replacement of a water ring element.
Configurations of charge air guide elements as disclosed herein may further allow implementing a charge air guide element for different configurations of internal combustion engines such as in-line configurations or V-configurations.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
The following is a detailed description of exemplary embodiments of the present disclosure. The exemplary embodiments described therein and illustrated in the drawings are intended to teach the principles of the present disclosure, enabling those of ordinary skill in the art to implement and use the present disclosure in many different environments and for many different applications. Therefore, the exemplary embodiments are not intended to be, and should not be considered as, a limiting description of the scope of patent protection. Rather, the scope of patent protection shall be defined by the appended claims.
The present disclosure may be based in part on the realization that EGR may result in damages to the charge air system, which results in the potential requirement to ease replacement of damaged components of the charge air system. As a result, new configurations for medium speed internal combustion engines are disclosed that may improve accessibility of those components being affected by EGR and, in particular, allow the implementation of those affected components as replacement parts.
To reduce the affects of EGR, it was further realized that removing aggressive condensate may extend the lifetime of the affected components and that in particular a drainage system may be provided for the charge air guide elements.
Specifically, a charge air inlet manifold may be composed of modularized casted charge air guide elements each of which specifically interact with a respective water ring element. As the water ring element may need to be more often demounted for servicing the cylinder unit, a charge air guide element is proposed that may allow supplying cooling water to the water ring element and that may stay mounted while servicing the cylinder unit.
Moreover, it was realized that specific design choices allow applying the charge air guide elements for in-line engine configurations as well as V-configurations. Specifically, features such as mounts, cooling water drainage, and condensation drainage may be provided for various engine configurations such as in-line and V-configurations, resulting in an improved efficiency in design work and logistic of replacement parts.
In addition, the present disclosure discloses a mixing pipe for connecting a turbocharged system with an inlet manifold for implementing EGR in a compact manner.
Referring to
Internal combustion engine 1 may further comprise a two-stage turbocharged system 12 having a low-pressure stage turbocharger 26 and a high-pressure stage turbocharger 28, which form a sequential turbocharging system. Generally, turbochargers may be applied to use the heat and pressure of the exhaust gas of an engine to drive a compressor for compressing the charge air for the engine. Internal combustion engine 1 may further comprise a fuel tank, one ore more catalyst systems, and an engine control unit, which are not shown.
Cylinder units 16A-16I may each comprise a cylinder head part 17, a combustion chamber, and a cylinder associated for guiding a piston within a cylinder liner. The piston may be connected to the crankshaft. As indicated in
In addition to top side 21, engine block 10 may have end sides 18L and 18H, being opposite in a lengthwise direction 19 defined by the longitudinal arrangement of cylinder units 16A-16I. Engine block 10 may further have opposing long sides 20A, 20B being opposite in a direction orthogonal to lengthwise direction 19. Cylinder units 16A-16I may linearly be arranged between end sides 18L and 18H and parallel to long sides 20A, 20B.
Internal combustion engine 1 may comprise a charge air system, which includes, for example, an intake manifold 22, and an exhaust gas system, which includes, for example, an exhaust manifold 24. For EGR, a fluid connection 36 between the exhaust gas system and the charge air system may be provided such that in a controlled manner exhaust gas can be mixed with the charge air before charging the combustion chamber. In
Intake manifold 22 may extend on top of top side 21 in lengthwise direction 19 and may be fluidly connected to each of cylinder units 16A-16I. Accordingly, top side 21 may be configured for mounting charge air inlet manifold 22, specifically, its components as explained below, thereon. Top side 21 may be free of any charge air openings that would provide a fluid connection from a fluid charge air passage 34 within the engine block to intake manifold 22.
Intake manifold 22 may be connected to high-pressure turbocharger 28 via mixing pipe 29 and to inlet openings of cylinder units 16A-16I. Each of cylinder units 16A-16I may be provided with at least one inlet valve (not shown) configured to open or close the fluid connection between intake manifold 22 and the combustion chamber of the respective cylinder unit.
Intake manifold 22 is separate from engine block 10 and may be comprised of a sequence of separately configured charge air guide elements 23A-23I that are mounted at top side 21. For example, top side 21 may comprise screw holes for mounting the charge air guide elements 23A-23I thereon. As disclosed below, some of those screw holes may extend orthogonally into top side 21, while some screw holes may extend into engine block under an angle unequal 90° with respect to top side 21.
Charge air guide elements 23A-23I may be configured as separate parts to allow piecewise assembly of individual cylinder units. Moreover, the specific configuration described herein may allow servicing a cylinder unit such as cylinder liner, piston, valves, etc. without removing the respective charge air guide element.
As shown in
Generally, when internal combustion engine 1 is operated, combustion chambers may be charged with charge air provided via intake manifold 22. After combustion, exhaust gas generated by the combustion process may be released from cylinder units 16A-16I via exhaust manifold 24.
As shown in
At end side 18L (also referred to as low-pressure side), low-pressure stage turbocharger 26 may be fixedly attached to engine block 10, for example directly or as a unit in combination with other components such as a charge air coolant block, for example a first cooler 30 etc.
At end side 18H (also referred to as high-pressure side), high-pressure stage turbocharger 28 may be fixedly attached to engine block 10, for example directly or as a unit in combination with other components such as a charge air coolant block, for example a second cooler 32 etc.
By mounting the turbochargers 26, 28 at opposite sides of engine block 10, mounting may be simplified and space may be used effectively, while providing easy access to the engine's components from long sides 20A, 20B and from the top.
Compressor connection 34 may provide a passage from end side 18L to end side 18H within the one-piece casted engine block 10 but is otherwise closed air tight. As shown in
The outlet of compressor CL may be connected via first cooler 30 to compressor connection 34. An outlet of compressor CH may be connected via second cooler 32 and mixing pipe 29 with intake manifold 22.
During operation of engine 1, the charge air may be twice compressed and cooled before charging of the combustion chambers of cylinder units 16A-16I. For example, for medium speed large internal combustion engines, compressor CL may compress the charge air to 3-5 bar at 180° C. Cooler 30 may cool the charge air from about 180° C. to 45° C. Compressor CH may compress the charge air to 7-8 bar at 180° C. and cooler 32 may cool the charge air from about 180° C. to 45° C.
The cooling may result in condensation within the charge air system and its components. In particular with EGR or various types of fuels, the condensate may become chemically reactive and, in particular, may affect the wall structure of the charge air systems in regions where a condensate may accumulate. As disclosed herein, the charge air guide elements may be provided with specific drainage ports to remove the aggressive condensate from the charge air system.
Within the combustion chambers, further compression of the charge air may be caused through the movement of the pistons. At the end of the compression cycle, an appropriate amount of fuel such as diesel oil, marine diesel oil, heavy fuel oil, alternative fuels, or a mixture thereof, may be injected into the combustion chambers. The fuel may be combusted with the compressed charged air and produce exhaust gas, which may be discharged via exhaust manifold 24.
An outlet of exhaust manifold 24 may be connected to an inlet of turbine TH. An outlet of turbine TH may be fluidly connected with an inlet of turbine TL via turbine pipe connection 35 and an outlet of turbine TL may release the exhaust gas. The exhaust gas system may additionally comprise one or more catalyst systems and/or one or more exhaust gas filtering systems that may be arranged, for example, externally or within turbine pipe connection 35.
The above described operation of internal combustion engine 1 may provide power to turn the crankshaft, for example, to drive a generator.
Referring to
Water ring element 40 may comprise a valve drive feed trough section 41 and a water ring section 42 for providing cooling water to the cylinder liner of the respective cylinder unit. Valve drive feed trough section 40 may comprise an opening 43B for having drive stems for operating the valves extending there through. Water ring element 40 may be the basis for mounting cylinder head part 17 thereon. A control air through hole 43C may further be integrated in the wall structure of water ring element 40 to provide pressurized control air to cylinder head part 17.
Water ring element 40 may comprise six screw guiding holes 43A that are arranged around water ring section 42 and extend within its wall structure, for example, in direction of the cylinder axis. For each cylinder unit 16A-16I, top side 21 of engine block 10 may have six tap holes surrounding a piston opening. Mounting water ring element 40 together with the respective cylinder unit (not shown in
In in-line configuration, top side 21 of engine block 10 may comprise a series of piston openings linearly arranged in the direction from first end side 18L to second end side 18H, while in V-configuration, the top side may include, for each of the two cylinder banks, a top section that is tilted with respect to the other and comprises a series of piston openings linearly arranged.
In the mounted state, a cylinder liner may reach from a respective cylinder head part 17 through the respective water ring section 42 and further through top side 21 into engine block 10.
Water ring section 42 may be configured for guiding coolant (for example, cooling water of a high temperature cooling circuit of the engine) around the cylinder liner and towards cylinder head 17 for cooling the cylinder liner and cylinder head during operation of the engine. In the mounted state, water ring section 42 may surround the respective cylinder liner such that a gap exists between water ring section 42 and the cylinder liner, which forms a water path around the cylinder liner.
Water ring element 40 may comprise cooling water connections for receiving cooling water from and returning cooling water to charge air guide element 23. As shown in
The cooling water, which circulated around the cylinder liner and was guided upwards into the cylinder head, may be returned from the cylinder head into a return connection 44B. Return connection 44B may comprise a channel 44C extending within the wall structure, for example, in direction of the cylinder axis. Return connection 44B may form, at an outside of the wall structure, a tab-like structure such that a water outlet opening is formed to open towards the engine block side of water ring 40. The tab-like structure of return connection 44B may be positioned next to the tab-like structure of supply connection 44A.
As the water connections are directed downwards towards the engine block side of water ring 40, they may be connectable, for example, via sealing inserts 47 to counterpart water connections of cooling water channels of charge air guide element 23 described below.
Charge air guide element 23 may comprise an air channel system inside. Specifically, charge air guide element 23 may comprise an inlet opening 45A on a first side of charge air guide element 23, a first outlet opening 45B at a second side being opposite to the first side, thereby providing a fluid connection (first passage 48A) from the first side to the second side (specifically, to first outlet opening 45B) in lengthwise direction 19 when mounted on top side 21.
As illustrated above with reference to
Referring again to
Referring to
Integrated in its wall structure, charge air guide element 23 may comprise cooling water channels for fluidly connecting cooling water pipes 70 (shown in
Supply channel 50A and return channel 50B may extend within the wall structure of charge air guide element 23. At the water ring side, supply channel 50A and return channel 50B may each comprise an opening 52 opening in the same direction as opening 45C (in the mounted state in a direction away from engine block 10) such that, for example, when sealing inserts 47 are positioned within openings 51, water ring element 40 may be lowered onto engine block 10 and a water tight connection between supply connection 44A and supply channel 50A as well as between return connection 44B and return channel 50B may be established. Similarly, water ring element 40 may be removed without demounting charge air guide element 23.
Within the wall structure of charge air guide element 23, supply channel 50A and return channel 50B may extend for about 180° around passage 48A, at first along the engine block side and then along an access side (opposite to the water ring side).
At the upper portion of the access side, there may be provided two pairs of openings for establishing a fluid connection to cooling water pipes. The openings may open in a direction that allows access in dependence of the type of engine configuration. For example, one pair of openings for in-line configuration may open in direction away from the engine in horizontal direction and one pair of openings for V-configuration may open in direction away from the engine in vertical direction as explained in detail with reference to
For each pair, the openings may be positioned next to each other in axial direction of passage 48A, in the mounted state along length direction 19.
As shown in
Next to the two pairs of openings, a mounting surface 62 with tab holes 61 may be provided for mounting a holder such as holder 25 in
Referring to
Cooling water drainage ports 52A may further allow curing the cooling water channels after the casting. For example, the cooling water channels may be casted to have two sections extending essentially linearly from the cooling water drainage ports 52A.
In some embodiments, condensate drainage ports may be provided to fluidly connect first passage 48A with the outside at positions in which condensate may accumulate during operation. For example, condensate a drainage port 54A may be positioned next to cooling water drainage ports 52B and connect to the inside for removing condensate when charge air guide element 23 is mounted at an in-line configured engine. For V-configuration, a condensate drainage port 54B may be positioned below openings 45B and connect to the inside for removing condensate when charge air guide element 23 is mounted at a V-configured engine (see
Charge air guide element 23 may be mounted via four screws inserted into screw guiding holes. For example, charge air guide element 23 may comprise at the water ring side, two screw guiding holes 64A that are directed essentially orthogonally towards the engine block side. Charge air guide element 23 may further comprise two screw guiding holes 64B at the access side, which may be positioned under an angle with respect to screw guiding holes 64A. Respective tap holes extending orthogonal to top side 21 and an angle of, for example, 70° to top side 21 may be provided in engine block 10.
The angle may be selected in accordance with the V-configuration for which the charge air guide element may be used. For example, V-configuration with two cylinder banks may be characterized by the tilt angle between the bank sections of the engine block top side. In some embodiments, a horizontal transition side 21A may connect the bank sections.
When a charge air guide element 23 is mounted to an engine in V-configuration, screw guiding holes 64A may be orthogonally directed onto each bank section (not shown in
As exemplarily shown in
The outer shapes of water ring 40 and charge air guide element 23 may be configured such that water ring 40 may be removed and mounted without the need of demounting charge air guide element 23 for in-line and V-configurations.
As an example,
Mixing pipe 29 may be fluidly connected via a valve (not shown) with fluid connection 36 for connecting the charge air system with the exhaust gas system. Thereby, exhaust gas may be mixed with charge air in a controlled manner before being distributed to the combustion chambers via inlet manifold 22.
Mixing pipe 29 may also comprise a condensate drainage located at the lowest point when mounted between high pressure cooler 32 and intake manifold 22.
In general, the various drainage ports may be connected to a common drainage system ensuring proper draining under various operating conditions that occur, for example, in marine applications.
Charge air guide element 123 comprises an air channel system inside. Specifically, charge air guide element 123 comprises an inlet opening 145A on a first side of charge air guide element 123, a first outlet opening 145B at a second side being opposite to the first side, thereby providing a fluid connection (first passage 148A) from the first side to the second side (specifically, to first outlet opening 145B) in lengthwise direction 19 when mounted on the top side of an engine block.
As illustrated above with reference to
Referring again to
Integrated in its wall structure, charge air guide element 123 comprises a pair of cooling water channels connected to a connecting pipe element 49 (shown in
Specifically, in the mounted state, a supply channel 150A extends from an supply inlet opening 160Bs to a supply outlet opening 151s and a return channel 150B extends from a return inlet opening 151r to a return outlet opening 160Br. Supply inlet opening 160Bs, supply outlet opening 151s, return inlet opening 151r, and return outlet opening 160Br open essentially in the direction into which the second passage 148B of the supply section opens at the top side of charge air guide element 123. The essentially identical orientation of supply inlet opening 160Bs, supply outlet opening 151s, return inlet opening 151r, return outlet opening 160Br, and second outlet opening 145C simplifies the assembly and demounting of water ring element 140 and charge air guide element 123 as well as the providing of a simple cooling water circuit to and from the cooling water pipes.
In other words, supply channel 150A fluidly connects the cooling water pipe with a water inlet opening 144As of supply connection 144A, for example, configured in a tap-like manner and a return channel 150B fluidly connects the return pipe with a water outlet opening 144Br of return connection 144B.
Supply channel 150A and return channel 150B extend within the wall structure of charge air guide element 123. Within the wall structure of charge air guide element 123, supply channel 150A and return channel 150B may extend for about 180° around passage 148A, at first along the engine block side and then along an access side (which is opposite to the water ring side).
In contrast to the embodiment of
Cooling water channels 150A and 15B of charge air guide element 123 may further comprise cooling water drainage ports, for example, cooling water drainage ports 152A in a central part of the cooling water channels and cooling water drainage ports (not shown) at the water ring side opening, for example, in a direction into which opening 145A opens. As understood by the skilled person, the cooling water drainage ports can be sealed to close the cooling circuit during operation.
In some embodiments, condensate drainage ports may be provided to fluidly connect first passage 148A with the outside at positions in which condensate may accumulate during operation. For example, a condensate drainage port 154A next to cooling water drainage ports 152A connects to the inside for removing condensate when charge air guide element 123 is mounted at an in-line configured engine. For V-configuration, a condensate drainage port may be provided as disclosed in connection with
It is referred to
The outer shapes of water ring element 140 and charge air guide element 123 may be configured such that water ring element 140 may be removed and mounted without the need of demounting charge air guide element 123 for in-line and V-configurations.
Referring to
From the cylinder head (not shown), the cooling water enters a cooling water return conduit 144B through an return conduit opening 244Br at the top of water ring element 140. The top is configured as, for example, a cylinder head interface. Cooling water return conduit 144B extends essentially axially along the wall of water ring element 140 and forms a tab-like structure that comprises water outlet opening 144Br. A sealed connection to return channel 150B is provided by a sealing insert 147 fitted into return conduit opening 244Br and return inlet opening 151r. Return channel 150B extends at the bottom of charge air element 123 from the water ring side to the access side and then bends upwards to the top side of charge air element 123 to open into return outlet opening 160Br. Prior bending towards return outlet opening 160Br, a, for example, straight connection to cooling water drainage port 152A is provided. The return flow is indicated by arrows 200.
The cooling water supply is essentially configured in a similar manner, with the difference, that supply connection 144A opens into the inside of water ring element 140.
Herein, the term “internal combustion engine” may refer to internal combustion engines which may be used as main or auxiliary engines of stationary power providing systems such as power plants for production of heat and/or electricity as well as in ships/vessels such as cruiser liners, cargo ships, container ships, and tankers. Fuels for internal combustion engines may include diesel oil, marine diesel oil, heavy fuel oil, alternative fuels or a mixture thereof, and natural gas.
In addition, the term “internal combustion engine” as used herein is not specifically restricted and comprises any engine, in which the combustion of a fuel occurs with an oxidizer to produce high temperature and pressure gases, which are directly applied to a movable component of the engine, such as pistons or turbine blades, and move it over a distance thereby generating mechanical energy. Thus, as used herein, the term “internal combustion engine” comprises piston engines and turbines.
Examples of internal combustion engines for the herein disclosed configuration of a two-stage turbocharged system include medium speed internal combustion diesel engines, like inline and V-type engines of the series M20, M25, M32, M43 manufactured by Caterpillar Motoren GmbH & Co. KG, Kiel, Germany, operated in a range of 500 to 1000 rpm.
Medium speed internal combustion engines may be large stand-alone engines that therefore provide reasonable access to the end sides of the engine block.
Herein a fluid connection generally may correspond to a component providing a fluid connection, for example, via an internal pathway having at least two openings connected by a side wall, such as for example a pipe. Components providing fluid pathways of the charge air system and the exhaust gas system may be connected with each other, for example, by flange connections as indicated in some of the figures.
In some embodiments, neighbouring charge air guide elements may be fluidly connected via a conduct, for example, a plain conduits or bellow.
Moreover, the mounting aspect and the aspect of the cooling channel system are independently of each other addable to charge air guiding elements.
The design of the charge air guide elements and water ring elements as disclosed herein may be applicable to single or multistage turbocharged engines.
Moreover, the charge air guide element may comprise each of the aspect of cooling channels integrated in its wall structure and the aspect of the mounting using angled mounting channels separately or in combination.
Although the preferred embodiments of this invention have been described herein, improvements and modifications may be incorporated without departing from the scope of the following claims.
Number | Date | Country | Kind |
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12163337.4 | Apr 2012 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2013/000996 | 4/3/2013 | WO | 00 |