DK201670153A1

DK201670153A1 - A cylinder cover for a large two-stroke turbocharged compression-ignited internal combustion engine

Info

Publication number: DK201670153A1
Application number: DKPA201670153A
Authority: DK
Inventors: Christian Adriansen; Morten Gebel
Original assignee: Man Diesel & Turbo Filial Af Man Diesel & Turbo Se Tyskland
Priority date: 2016-03-16
Filing date: 2016-03-16
Publication date: 2017-10-02
Also published as: KR101813947B1; CN107201964A; KR101889709B1; KR20170107911A; CN107201964B; DK179175B1; JP2017166478A; KR20170107940A; JP6298552B2

Abstract

A cylinder cover (22) for a large two-stroke turbocharged compression ignited internal combustion engine. The cylinder cover comprises an annular body with an upper side (47) and a lower side (48). The annular body has a lower portion (36) defining a hollow that is open to the lower side (48) for forming an upper part of a combustion chamber (25). The annular body has a upper portion (35) defining a central passage (38) that opens to said hollow and opens to said upper side and annular body comprises an integral an integral radially outward projecting flange (30) at said lower side (48).

Description

A CYLINDER COVER FOR A LARGE TWO-STROKE TURBOCHARGED COMPRESSION-IGNITED INTERNAL COMBUSTION ENGINE

TECHNICAL FIELD

The disclosure relates to a cylinder cover for a large two-stroke turbocharged compression-ignited internal combustion engine and to large two-stroke turbocharged compression-ignited internal combustion engine. The disclosure also relates to an exhaust valve for a large two-stroke turbocharged compression-ignited internal combustion engine.

BACKGROUND

Large two-stroke turbocharged compression-ignited internal combustion engines of the crosshead type are typically used in propulsion systems of large ships or as prime mover in power plants. The sheer size, weight and power output renders them completely different from common combustion engines and places large two-stroke turbocharged compression-ignited internal combustion engines in a class for themselves.

The cylinders of large two-stroke turbocharged compression-ignited internal combustion engines are formed by a cylinder liner provided with a single exhaust valve in the cylinder cover at the top of the cylinder liner and with a ring of piston controlled scavenge ports at the lower region of the cylinder liner.

The cylinder liner is carried by a cylinder frame that in turn is carried by the engine frame. The cylinder cover is clamped with a high force onto the cylinder liner by cylinder cover studs. The force that is applied by the cylinder cover studs needs to exceed with a margin the enormous force of the compression and combustion pressure acting on the cylinder cover. In order to withstand the forces of the pressure in the combustion chamber on the one hand and the forces of the cylinder cover studs on the other hand, the cylinder cover has to be extremely strong and robust. At the same time the cylinder cover has to be able to handle the high temperatures caused by the combustion process. Thus, high requirements are placed on the material quality of the body forming the cylinder cover. For the largest of the two-stroke compression-ignited internal combustion engines forged hardened and tempered steel is used.

The cylinder cover carries the exhaust valve and the fuel valves (typically three fuel valves per cylinder for a single fuel engine and six per cylinder for a dual fuel engine) where the positioning is controlled by the limited space and the cylinder cover is provided with a central passage connecting the combustion chamber to the to the exhaust bend.

Basically, a prior art cylinder cover is a solid block of material. The high-strength requirements have led to very high wall thickness, especially in the upper portion of the cylinder cover. These large wall thicknesses generate problems with ensuring proper material quality throughout the body of the cylinder cover, especially in areas with the material of the cylinder cover is distant from the surface. Consequently, ensuring proper material quality throughout the cylinder cover is difficult, cumbersome and expensive. Moreover, material costs for cylinder covers with a very large wall thickness is significant and only forged cylinder covers can fulfill the requirements at present.

SUMMARY

It is an object of the invention to provide a cylinder cover that reduces or at least overcomes the problems mentioned above .

The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures .

According to a first aspect there is provided a cylinder cover for a large two-stroke turbocharged compression ignited internal combustion engine, the cylinder cover comprising: - an annular body with an upper side and a lower side, - the annular body having a lower portion defining a hollow that is open to the lower side for forming an upper part of a combustion chamber, - the annular body having an upper portion defining a central passage that opens to the hollow and opens to the upper side, and - the annular body comprising an integral radially outward projecting flange at the lower side.

By providing a cylinder cover with an radially outward projecting flange at its lower side it becomes possible to clamp the cylinder cover onto the cylinder liner using an annular retainer. This in turn allows a much thinner, more slender construction of the cylinder cover with a more evenly distributed wall thickness. Thereby, material costs are reduced and production costs are reduced since the even distributional the wall thickness and the less thick walls make it much easier to ensure proper material quality throughout the cylinder cover. Further, the lighter and more slender cylinder cover allows for easier and less expensive overhaul of the cylinder cover. Moreover, the thinner wall of the cylinder cover renders it much easier to position the fuel valves .

According to a first possible implementation of the first aspect the cylinder cover is provided on its lower side with a lower annular contact surface for engaging a upper annular surface of a cylinder liner.

According to a second possible implementation of the first aspect the radially outward projecting flange has an upwardly directed contact surface for supporting an annular retainer.

According to a third possible implementation of the first aspect the radially outward projecting flange has a downwardly directed surface that is flush with the lower annular contact surface .

According to a fourth possible implementation of the first aspect the central passage is provided on an inwardly directed annular ledge with an upwardly facing support surface for supporting a downwardly facing annular contact surface of the exhaust valve.

According to a fifth possible implementati on of the first aspect the annular body of the cylinder cover is formed by a single piece of material.

According to a sixth possible implementation of the first aspect the annular body has a substantially evenly distributed radial wall thickness.

According to a seventh possible implementation of the first aspect the cylinder cover further comprises a separate annular retainer sized and shaped to fit around the lower portion with a portion of a bottom surface of the annular retainer engaging the upwardly directed contact surface.

According to an eighth possible implementation of the first aspect the outer diameter of the upper portion is equal or less than the outer diameter of the lower portion.

According to a ninth possible implementation of the first aspect the largest diameter of the lower portion is formed by the radially outwardly projecting flange.

According to a tenth possible implementation of the first aspect the annular recess is disposed between the lower portion and the annular retainer.

According to a second aspect there is provided a large two-stroke turbocharged compression—ignited internal combustion engine with crossheads, the engine comprising: a cylinder cover on a cylinder liner, the cylinder liner being carried by a cylinder frame, an annular retainer engaging the cylinder cover, a plurality of cylinder cover studs connecting the annular retainer to the cylinder frame for clamping the cylinder cover on the cylinder liner.

By providing an engine with a cylinder cover that is retained by annular retainer the cylinder cover can be constructed with significantly less material and with a lower maximum wall thickness which greatly facilitates obtaining the required material quality throughout the cylinder cover. Maintenance and overhaul is also greatly facilitated.

According to a first implementation of the second aspect the cylinder cover studs clamp the annular retainer on the cylinder cover.

According to a second possible implementation of the second aspect the annular retainer is placed over a portion of the body of the cylinder cover with the annular retainer engaging an outwardly projecting flange of the cylinder cover.

According to a third possible implementation of the second aspect the annular retainer is provided with a plurality of through going holes through which the cylinder cover studs project.

According to a fourth possible implementation of the second aspect the cylinder cover studs are provided with nuts that engage an upper engagement surface of the annular retainer.

According to a fifth possible implementation of the second aspect the one end of the cylinder cover studs is anchored in the cylinder frame.

According to a third aspect there is provided an exhaust valve for a large two-stroke turbocharged compression-ignited internal combustion engine with an exhaust valve housing, the exhaust valve housing comprising: an exhaust bend with one end opening to a lateral side of the exhaust valve housing and the other end opening to the bottom of the exhaust valve housing, a bore for guiding the spindle of the exhaust valve, an integral outwardly projecting horizontally extending flange that is arranged below the end of the exhaust bend that opens to the lateral side of the exhaust valve housing, the integral outwardly projecting horizontally extending flange is provided with a plurality of through going bores for receiving bolts or studs for securing the exhaust valve housing to a cylinder cover.

By providing a flange at the low end of the exhaust valve housing the length of the bolts or studs connecting the exhaust valve housing to the cylinder cover is significantly reduced. Further, a large number of smaller bolts or studs can be used as opposed to a few major bolts or studs since the exhaust bens is no longer "in the way".

According to a fourth aspect there is provided a large two-stroke turbocharged compression-ignited internal combustion engine with crossheads, the engine comprising: a cylinder cover on a cylinder liner, the cylinder liner being carried by a cylinder frame, and an exhaust valve according to the third aspect bolted onto the cylinder cover by bolts or studs that are anchored in the cylinder cover and project through holes in the integral outwardly projecting horizontally extending flange.

These and other aspects of the invention will be apparent from and the embodiment(s) described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the invention will be explained in more detail with reference to the example embodiments shown in the drawings, in which:

Fig. 1 is an elevated front view of a large two-stroke diesel engine according to an example embodiment,

Fig. 2 is an elevated side view of the large two-stroke engine of Fig. 1,

Fig. 3 is a diagrammatic representation the large two-stroke engine according to Fig. 1,

Fig. 4 is a sectional view of the cylinder frame and a cylinder liner with a cylinder cover according to an example embodiment with an exhaust valve fitted thereto,

Fig. 5 is a different angle sectional view of the cylinder frame and a cylinder liner with a cylinder cover according to an example embodiment with an exhaust valve fitted thereto, Fig. 6 is a detailed side view on the upper portion of a cylinder liner with the cylinder cover, annular retainer and the exhaust valve,

Fig. 7 is a side view of a cylinder cover according to an example embodiment,

Fig. 8 is a sectional view of the cylinder cover of Fig. 7 with fuel valves and an annular retainer installed,

Fig. 9 is a sectional view of the cylinder cover of Fig. 7 without the fuel valves and with an annular retainer installed,

Fig. 10 is an elevated view of the cylinder cover of Fig. 7 Fig. 11 is an elevated view of the annular retainer of Fig. 8 and 9,

Fig. 12 is an elevated view of the cylinder cover of Fig. 8 with the annular retainer installed, and

Fig. 13 is a top view of the cylinder cover of Fig. 8 with the annular retainer installed.

DETAILED DESCRIPTION

In the following detailed description, an internal combustion engine will be described with reference to a large two-stroke low-speed turbocharged compression-ignited internal combustion engine with crossheads in the example embodiments. Figs. 1, 2 and 3 show a large low-speed turbocharged two- stroke diesel engine with a crankshaft 8 and crossheads 9. Fig. 3 shows a diagrammatic representation of a large low-speed turbocharged two-stroke diesel engine with its intake and exhaust systems. In this example embodiment the engine has six cylinders in line. Large low-speed turbocharged two-stroke diesel engines have typically between four and fourteen cylinders in line, carried by a cylinder frame 23 that is carried by an engine frame 11. The engine may e.g. be used as the main engine in a marine vessel or as a stationary engine for operating a generator in a power station. The total output of the engine may, for example, range from 1,000 to 110,000 kW.

The engine is in this example embodiment a compression-ignited engine of the two-stroke uniflow type with scavenge ports 18 at the lower region of the cylinder liners 1 and a central exhaust valve 4 at the top of the cylinder liners 1. The scavenge air is passed from the scavenge air receiver 2 to the scavenge ports 18 of the individual cylinders 1. A piston 10 in the cylinder liner 1 compresses the scavenge air, fuel is injected from fuel injection valves in the cylinder cover 22, combustion follows and exhaust gas is generated.

When an exhaust valve 4 is opened, the exhaust gas flows through an exhaust duct associated with the cylinder 1 into the exhaust gas receiver 3 and onwards through a first exhaust conduit 19 to a turbine 6 of the turbocharger 5, from which the exhaust gas flows away through a second exhaust conduit via an economizer 20 to an outlet 21 and into the atmosphere. Through a shaft, the turbine 6 drives a compressor 7 supplied with fresh air via an air inlet 12. The compressor 7 delivers pressurized scavenge air to a scavenge air conduit 13 leading to the scavenge air receiver 2. The scavenge air in conduit 13 passes an intercooler 14 for cooling the scavenge air.

The cooled scavenge air passes via an auxiliary blower 16 driven by an electric motor 17 that pressurizes the scavenge air flow when the compressor 7 of the turbocharger 5 does not deliver sufficient pressure for the scavenge air receiver 2, i.e. in low- or partial load conditions of the engine. At higher engine loads the turbocharger compressor 7 delivers sufficient compressed scavenge air and then the auxiliary blower 16 is bypassed via a non-return valve 15.

Figs. 4, 5 and 6 show a cylinder liner generally designated 1 for a large two-stroke crosshead engine with a cylinder cover 22 installed thereon and with an exhaust valve 4 installed on the cylinder cover 22. Depending on the engine size, the cylinder liner 1 may be manufactured in different sizes with cylinder bores typically ranging from 250 mm to 1100 mm, and corresponding typical lengths ranging from 1000 mm to 4500 mm. The cylinder liner 1 is normally manufactured in cast iron. Large two-stroke crosshead engines are developed towards very high effective compression ratios, such as 1:16 to 1:20, which entail heavy loads on the elements that need to withstand the pressure in the combustion chamber 25, such as e.g. the cylinder liner 1, the piston 10 and the cylinder cover 22.

In Fig. 4 the cylinder liner 1 is shown mounted in the cylinder frame 23 with the cylinder cover 22 placed on the top of the cylinder liner 1 with a gas tight interface there between. An annular retainer 30 is fitted over the cylinder cover 22 with an outwardly projecting rim 31 of the cylinder cover 22 clamped between the annular retainer 30 and the top of the cylinder liner 1. A sharp transition in the thickness of the cylinder liner 1 around the middle of the axial extent of the cylinder liner 1 serves as a shoulder that allows the cylinder liner 1 to rest on the cylinder frame 23. The annular retainer 30 is pressed onto the cylinder cover 22 with great force applied by cylinder cover studs 24 onto the upper surface of the annular retainer 30, and the cylinder cover 22 is pressed with great force applied by the annular retainer 30 onto the cylinder liner 1.

Fuel valves 27 are installed in the cylinder cover 22 with the nozzle at the front end of the fuel valve 27 projecting into the combustion chamber 25.

The exhaust valve arrangement comprise the exhaust valve 4 with its valve stem and the valve disk which is shown resting on the valve seat 51.

The exhaust valve arrangement comprises a housing 28 that includes the exhaust bend 50. The exhaust bend 50 opens at one end to the bottom side of the exhaust valve where the valve seat 51 is provided and its other and to a lateral side of the exhaust valve housing 28. The opening of the exhaust bend 50 at the lateral side of the valve housing 28 connects to an exhaust duct that leads to the exhaust gas receiver 3.

The exhaust valve housing is provided with a bore that guides the exhaust valve spindle. A hydraulic exhaust valve actuator 52 is installed on the upper side of the exhaust valve housing 28 and acts on the free end of the exhaust valve spindle for opening the exhaust valve. The exhaust valve actuator 52 also includes an pneumatic spring 53 for urging the exhaust valve to return to its closed position.

The exhaust valve housing 20 is provided with an outwardly projecting exhaust valve housing flange 29 that is provided with a plurality of through going bores through which exhaust valve studs 32 project. The exhaust valve studs 32 are anchored in the top of the cylinder cover 22. Nuts 33 engage the upper end of the exhaust valve studs 32 and act on the exhaust valve housing flange 29 for bolting the exhaust valve housing 28 onto the cylinder cover 22.

The exhaust valve housing flange 29 is arranged below the lateral opening of the exhaust bend 50. The exhaust valve housing 28 is supported by the ring shaped member that forms the valve seat 51 which in turn is supported by an inwardly projecting ledge 42 of the cylinder cover 22 (Fig. 8) for supporting the exhaust valve.

The exhaust valve housing flange 29 is arranged below the opening of the exhaust bend 50 at the lateral side of the valve housing 28. In prior art exhaust valves, the nuts of the exhaust valve studs engaged the surface at the top of the exhaust valve housing, i.e. a surface above the lateral opening of the exhaust bend 50. These prior art exhaust valves have the disadvantage that the exhaust bend is in the way for the exhaust studs, which means that typically only four relatively massive exhaust studs have been deployed. By arranging the surface that the nuts 33 of the exhaust studs engage below the lateral opening of the exhaust bend 50, the length of the exhaust studs can be significantly reduced and a large number of smaller studs can be used which allows for a possible cost reduction. This also allows optimized positioning of various valves.

Piping 54 serves to supply and remove liquid coolant, e.g. water to a cooling and arrangement at the upper portion of the cylinder liner 1, e.g. to the circumferential cooling recess 39 that in an embodiment is arranged between the cylinder cover 22 and the annular retainer 30.

With reference to Figs. 7 to 13 the cylinder 22 and the annular retainer 30 will be described in greater detail. In Fig. 8 the cylinder cover 22 is shown with fuel valves 27 installed and in Fig. 9 without the fuel valves 27 installed.

The cylinder cover 22 has an annular body with an upper side 47 and a lower side 48. The lower side 48 is provided with a lower annular contact surface 44 for engaging a upper annular surface of a cylinder liner 1. The upper side 47 can in an embodiment be formed an annular surface 45 that is provided with a plurality of threaded bores 41 in which the exhaust valve studs 32 are anchored. The annular body has a lower portion 36 defining a hollow 4 9 that is open to the lower side 48 for forming an upper part of the combustion chamber 25. The annular body of the cylinder cover 22 has an upper portion 35 defining a central passage 38 that opens to the hollow 49 and opens to the upper side 47 of the cylinder cover 22 so that the passage 38 allows exhaust gas to flow from the hollow 49 to the exhaust bend 50 when the exhaust valve 4 is open. In an embodiment the lower portion 36 is directly connected to the upper portion 35, or as shown there is provided a preferably tapering transition portion 55.

The annular body is provided with an integral radially outward projecting flange 31 at the lower side 48 of the cylinder cover 22. The radially outward projecting flange 31 has an upwardly directed contact surface 43 for supporting the annular retainer 30. The radially outward projecting flange 31 has a downwardly directed surface that is preferably flush with the lower annular contact surface 44.

The central passage 38 is provided on an inwardly directed annular ledge with an upwardly facing support surface 42 for supporting a downwardly facing annular contact surface of the exhaust valve.

In an embodiment the annular body of the cylinder cover 22 is formed by a single piece of material, i.e. the body of the cylinder cover 22 is formed as one integral element.

The construction of the annular body is such that it has a substantially evenly distributed wall thickness. In the shown embodiments the transition between the lower portion 36 and the upper portion 35 is in the form of a tapered section 55 in order to maintain a substantially constant wall thickness for the annual member. However, the transition between the lower portion 36 and the upper portion 35 does not need to be tapered, it can e.g. be a right angled transition.

The annular body is provided with protrusions 56 that are provided to this place for bores 34 in which the fuel valves 27 are received. In the shown embodiments there are 3 fuel valves per cylinder, but depending on engine design and on the number of fuels that the engine is supposed to operate with there can be between two and six fuel valves per cylinder .

The annular retainer 30 is an element separate from the cylinder cover 22 and the annular retainer 30 is sized and shaped to fit around the lower portion 36 with a radially inner portion of a bottom surface of the annular retainer 30 engaging the upwardly directed contact surface 43 of the radially outward projecting flange 31.

The annular retainer 30 is provided with a central opening with a diameter that is equal or slightly larger than the outer diameter of the lower portion 36 of the cylinder cover 22. The (outer) diameter of the outward projecting flange 31 is larger than the diameter of the central opening of the annular retainer 30.

However, the (outer) diameter of the outward projecting flange 31 is smaller than the outer diameter of the annular retainer 30, so that the cylinder cover studs 24 can pass the outward projecting flange 31 but still be received in the through going bores 46 in the annular retainer 30. The through going bores 46 are placed such that the cylinder cover studs 24 are arranged closely around the perimeter of the radially outwardly projecting flange 31.

The outer diameter of the upper portion 35 is equal or less than the outer diameter of the lower portion 36, so that the annular retainer 30 can be placed over the main body of the cylinder cover 22 and on the upwardly directed contact surface 43 of the outward projecting flange 31. Thus, the largest outer diameter of the cylinder cover 22 is formed by the radially outwardly projecting flange 31. This construction also allows the annular retainer 30 to be removed by simply lifting it up and away from the cylinder cover 22, thereby facilitating maintenance.

In an embodiment, an annular cooling recess 39 is formed in the lower portion 36 and closed off by the annular retainer 30. The annular cooling recess provides for a circumferentially substantially even cooling distribution. The annular retainer 30 is provided with an upright rim 40 to form a strong back that surrounds the lower portion 36 of the cylinder cover 22 in a way that seals annular recess 39. A rounded transition between the annular cooling recess 39 and the radially outwardly projecting flange 31 reduces tension in the transition.

The annular cooling recess 39 connects to a plurality of substantially radially directed cooling channels 37 in the intermediate section of the cylinder cover 22 and the cooling channels 37 connect to cooling channels in the exhaust valve for cooling the latter.

The body of the cylinder cover 22 is in embodiment made from cast iron or cast steel. The body of the cylinder cover 22 is in another embodiment made from a high-strength, heat resistant steel, e.g. forged steel.

In an embodiment the annular retainer 30 is made of relatively inexpensive material such as e.g. cast-iron or low alloy steel that allows annular retainer 30 to be manufactured by casting.

The invention has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The reference signs used in the claims shall not be construed as limiting the scope.

Claims

1. A cylinder cover (22) for a large two-stroke turbocharged compression ignited internal combustion engine, said cylinder cover comprising: - an annular body with an upper side (47) and a lower side (48) , - said annular body having a lower portion (36) defining a hollow (49) that is open to said lower side (48) for forming an upper part of a combustion chamber (25), - said annular body having an upper portion (35) defining a central passage (38) that opens to said hollow (49) and opens to said upper side (47), and - said annular body comprising an integral radially outward projecting flange (31) at said lower side (48).

2. A cylinder cover (22 according to claim 1, wherein said cylinder cover (22) is provided on its lower side (48) with a lower annular contact surface (44) for engaging a upper annular surface of a cylinder liner (1).

3. A cylinder cover (22) according to claim 1 or 2, wherein said radially outward projecting flange (31) has an upwardly directed contact surface (43) for supporting an annular retainer (30).

4. A cylinder cover (22) according to claim 2 or 3, wherein said radially outward projecting flange (31) has a downwardly directed surface that is flush with said a lower annular contact surface (44).

5. A cylinder cover (22) according to any one of claims 1 to 4, wherein said annular body is formed by a single piece of material.

6. A cylinder cover (22) according to any one of claims 1 to 5, wherein said annular body has a substantially evenly distributed wall thickness.

7. A cylinder cover (22) according to any one of claims 1 to 6, further comprising a separate annular retainer (30) sized and shaped to fit around said lower portion (36) with a portion of a bottom surface of said annular retainer (30) engaging said upwardly directed contact surface (43)

8. A cylinder cover (22) according to any one of claims 1 to 8. wherein the outer diameter of said upper portion (35) is equal or less than the outer diameter of said lower portion (36) .

9. A cylinder cover (22) according to claim 8, wherein the largest diameter of said lower portion (36) is formed by said radially outwardly projecting flange (31).

10. A cylinder cover (22) according to any one of claims 8 to 9, wherein an annular recess is disposed between said lower portion (36) and said annular retainer (30) .

11. A large two-stroke turbocharged compression-ignited internal combustion engine with crossheads, said engine comprising: cylinder cover (22) on a cylinder liner (1), said cylinder liner (1) being carried by a cylinder frame (23), an annular retainer (30) engaging said cylinder cover (22), a plurality of cylinder cover studs (24) connecting said annular retainer (30) to said cylinder frame (23) for clamping said cylinder cover (22) on said cylinder liner (1).

12. An engine according to claim 11, wherein said annular retainer (30) is placed around a portion of the body of the cylinder cover (22) with said annular retainer (30) engaging an outwardly projecting flange (31) Qf said cylinder cover (22) .

13. An engine according to claim H or 12, wherein said annular retainer (30) is provided with a plurality of through going holes (46) through which said cylinder cover studs (24) project.

14. An engine according to claim 13, wherein said cylinder cover studs (24) are provided with nuts (26) that engage an upper engagement surface (49) of said annular retainer (30).

15. An engine according to any one of claims 11 to 14, wherein one end of said cylinder cover studs (24) is anchored in said cylinder frame (23).

16. An exhaust valve (4) for a large two-stroke turbocharged compression-ignited internal combustion engine, with an exhaust valve housing (28), said exhaust valve housing (28) comprising: an exhaust bend (50) with one end opening to a lateral side of the exhaust valve housing (28) and the other end opening to the bottom of the exhaust valve housing (20), a bore for guiding the spindle of the exhaust valve (4), an integral outwardly projecting horizontally extending flange (29) that is arranged below the end of the exhaust bend that opens to the lateral side of the exhaust valve housing (28), said integral outwardly projecting horizontally extending flange (2) is provided with a plurality of through going bores for receiving bolts or studs (32) for securing the exhaust valve housing to a cylinder cover (22).

17. A large two-stroke turbocharged compression-ignited internal combustion engine with crossheads, said engine comprising: a cylinder cover (22) on a cylinder liner (1), said cylinder liner (1) being carried by a cylinder frame (23), and an exhaust valve according to claim 16 bolted onto said cylinder cover (22) by bolts or studs that are anchored in said cylinder cover (22) and project through holes in said integral outwardly projecting horizontally extending flange (29).