KR20210008298A - Internal combustion engine - Google Patents

Abstract

Disclosed is a two-stroke uniflow scavenging crosshead internal combustion engine comprising at least one cylinder, a cylinder cover, a piston, a fuel gas supply system, and a scavenging air system. According to the present invention, the cylinder has a cylinder wall, the cylinder cover is arranged on top of the cylinder and has an exhaust valve, and the fuel gas supply system includes a fuel gas valve configured to inject fuel gas into the cylinder during a compression stroke. The engine further comprises a pre-chamber arranged at least partially in the cylinder wall. The pre-chamber opens into the cylinder through a first opening formed in the cylinder wall. The pre-chamber is configured to ignite a mixture of scavenge air and fuel gas within the cylinder.

Description

Internal combustion engine {INTERNAL COMBUSTION ENGINE}

The present invention relates to a two-stroke uniflow scavenging crosshead internal combustion engine and a pre-chamber member of a cylinder.

Two-stroke internal combustion engines are used as propulsion engines in ships such as container ships, bulk carriers and oil tankers. The reduction of unwanted emissions from internal combustion engines is becoming increasingly important.

An effective way to reduce the amount of unwanted exhaust gas is the conversion from fuel oil to fuel gas, for example heavy oil (HFO). The fuel gas can be injected into the cylinder at the end of the compression stroke, where it can be ignited immediately by the high temperature reached by the gas in the cylinder during compression or by ignition of the pilot fuel. However, injecting the fuel gas into the cylinder at the end of the compression stroke requires a large gas compressor to compress the fuel gas prior to injection to overcome the large pressure in the cylinder.

However, large gas compressors are expensive and complex to manufacture and maintain. A way to avoid the use of a large compressor is to configure the engine to inject fuel gas at the beginning of the compression stroke where the pressure in the cylinder is considerably low.

International Publication No. WO 2013/007863 discloses such an engine. A pilot ignition pre-chamber is provided in the cylinder cover to ensure proper ignition of the fuel gas. A predetermined amount of pilot fuel oil is injected into the pilot ignition pre-chamber and then self-igniting due to the temperature and pressure of the pilot ignition pre-chamber. This results in a spark that ignites the fuel gas in the main chamber of the cylinder.

However, cylinder covers with pre-chambers are problematic, due to the presence of other engine components such as exhaust valves, liquid fuel valves for dual-fuel engines, and fuel valves for potentially added triple fuel engines. This is because space resources in the cylinder cover are insufficient. The limited space in the cylinder cover is also a limitation on the number of separate pre-chambers that can be arranged in the cylinder cover.

Moreover, when designing the cooling system, control and optimize the temperature of the pre-chamber arranged in the cylinder cover, as all other components in the cover of the complex shape must also be considered to ensure that all components are properly cooled. It will be very difficult to do.

Therefore, it remains a problem to provide an alternative method of igniting fuel gas.

According to a first aspect, the present invention provides a two-stroke uniflow scavenging crosshead internal combustion engine (also simply referred to as'engine') comprising at least one cylinder, cylinder cover, piston, fuel gas supply system, and scavenging air system. ), wherein the cylinder has a cylinder wall, the cylinder cover is arranged at the top of the cylinder and has an exhaust valve, and the piston is arranged to be movable in the cylinder along a central axis between the bottom dead center and the top dead center. Wherein the scavenger air system has a scavenger air inlet arranged at a lower portion of the cylinder, and the fuel gas supply system comprises a fuel gas valve arranged at least partially on the cylinder wall and configured to inject fuel gas into the cylinder during a compression stroke. Thus allowing the fuel gas to be mixed with the scavenger air and allowing the mixture of scavenger air and fuel gas to be compressed before ignition, wherein the engine further comprises a pre-chamber arranged at least partially in the cylinder wall, The pre-chamber is opened into the cylinder through a first opening formed in the cylinder wall, and the pre-chamber is configured to ignite a mixture of scavenger air and fuel gas in the cylinder.

As a result, by providing a pre-chamber in the cylinder wall, the mixture of scavenger air and fuel gas in the cylinder will be ignited effectively without taking up space in the cylinder cover.

By providing a pre-chamber in the cylinder wall, greater flexibility is obtained for arranging the essential components in the cylinder cover, and also components such as an exhaust valve can be expanded. Furthermore, it will be possible to arrange several pre-chambers around the cylinder wall.

With regard to the actual combustion process, the pre-chamber arranged in the cylinder wall offers the advantage of facilitating the ignition of the fuel gas close to the inner wall. If the pre-chamber is arranged on the cylinder wall, the flame is oriented more horizontally, so that the flame can come into contact with a large part of the scavenger air and fuel gas mixture.

Furthermore, arranging the pre-chamber on the cylinder wall ensures that the pre-chamber temperature is not affected by the temperature of the cylinder cover, e.g., more effectively cooling the pre-chamber by differentiating the pre-chamber temperature over the load range of the engine. I can make it.

The internal combustion engine is preferably a large low speed turbocharged two-stroke crosshead internal combustion engine with uniflow scavenging for propulsion of marine vessels with a power of at least 400 kW per cylinder. The internal combustion engine may include a turbocharger configured to compress scavenger air by being driven by exhaust gas generated by the internal combustion engine. The internal combustion engine may be a dual-fuel engine having an auto cycle mode driven by fuel gas and a diesel cycle mode driven by alternative fuel such as heavy oil or marine diesel oil. These dual-fuel engines have a dedicated fuel supply system for injecting alternative fuels.

The internal combustion engine preferably comprises a plurality of cylinders, for example 4 to 14 cylinders. The internal combustion engine further includes a cylinder cover, an exhaust valve, a piston, a fuel gas valve, and a scavenger air inlet for each of the plurality of cylinders.

The fuel gas supply system is preferably configured to inject fuel gas through one or more fuel gas valves under a sonic condition, ie a speed equal to the speed of sound, ie a constant speed. Negative conditions can be achieved when the ratio of the pressure drop across the nozzle throat (minimum area cross-sectional area) is greater than approximately 2.

In some embodiments, the one or more fuel gas valves provide fuel into the cylinder during the compression stroke, at 0 degrees to 160 degrees from bottom dead center, at 0 degrees to 130 degrees from bottom dead center, or at 0 degrees to 90 degrees from bottom dead center. It is configured to inject gas.

The at least one fuel gas valve is arranged at least partially in a position on the cylinder wall between the top dead center and the bottom dead center, preferably above the scavenger air inlet. The one or more fuel gas valves may include nozzles arranged on the cylinder wall to inject fuel gas into the cylinder. Other parts (other than the nozzle) of the fuel gas valve can be arranged outside the cylinder wall.

Examples of fuel gases are liquefied natural gas (LNG), methane, ethane, ammonia and liquefied petroleum gas (LPG).

In some embodiments, the engine further comprises a pilot fuel supply system, the pilot fuel supply system comprising a pilot fuel valve arranged in the pre-chamber, the pilot fuel valve injecting pilot fuel into the pre-chamber. Is configured to

The pre-chamber can be configured to self-ignite the pilot fuel due to the temperature and pressure in the pre-chamber. Alternatively, the pilot fuel in the pre-chamber can be ignited by means comprising a spark plug or a laser igniter. The pilot fuel may be heavy oil or marine diesel oil, or any other fuel with suitable ignitability, and the amount of pilot fuel is accurately measured to the extent that it can ignite the mixture of fuel gas and scavenger air in the cylinder. These pilot fuel systems are much smaller in size compared to dedicated fuel supply systems for alternative fuels, making them more suitable for injecting the exact amount of pilot fuel, and dedicated fuel supply systems for alternative fuels are large-sized components. Therefore, it may not be suitable for this purpose. The pilot fuel supply system may be configured to inject a predetermined amount of pilot oil at an appropriate crank angle for optimal ignition of the main charge, close to top dead center. The pilot fuel ignition follows immediately after the pilot oil injection, and the main charge ignition follows immediately after the pilot oil ignition.

In some embodiments, at least one of the cylinders has a base member and a pre-chamber member, the pre-chamber member is arranged on top of the base member and the cylinder cover is arranged on top of the pre-chamber member, , The pre-chamber member is at least partially arranged in the cylinder wall of the pre-chamber member, and the pre-chamber is opened into the cylinder through an opening formed in the cylinder wall of the pre-chamber member.

This allows the pre-chamber member to be specifically designed to handle the high temperatures and pressures in the pre-chamber, for example by selecting an appropriate material. This makes it easier to perform maintenance on the pre-chamber. The pre-chamber member can be inserted between the base member and the cylinder cover with or without a gasket arrangement. The pre-chamber member can be pre-assembled with the base member before the cylinder cover is installed.

In some embodiments, the pre-chamber member of the cylinder is made of a different material than the base member of the cylinder.

The base member of the cylinder may be made of cast iron and the pre-chamber member may be made of steel.

In some embodiments, the engine further comprises a pre-chamber cooling system for cooling the pre-chamber, wherein the pre-chamber cooling system comprises a cooling channel proximate the pre-chamber to extract heat from the pre-chamber. Wherein the pre-chamber cooling system is configured to circulate a cooling fluid through the cooling channel.

Arranging the pre-chamber on the cylinder wall provides more space for the pre-chamber cooling system. This makes it possible to control the temperature of the pre-chamber more accurately, being less affected by other engine parameters such as exhaust valve closing timing, engine speed, engine load and the like. More precise control of the pre-chamber temperature reduces the amount of pilot fuel and/or makes it more suitable to use an alternative pilot fuel such as fuel gas, thereby reducing the emission of unwanted exhaust gases.

In some embodiments, the pilot fuel is fuel gas.

In some embodiments, the pilot fuel and the main fuel are the same type of fuel gas.

In some embodiments, the pre-chamber cooling system further comprises a control unit configured to control the flow of the cooling fluid and/or the inlet temperature of the cooling fluid.

In some embodiments, the control unit, depending on the engine load, engine speed, and/or the air-fuel equivalent ratio (λ) of the mixture of scavenger air and fuel gas, the flow of the cooling fluid and/or the inlet temperature of the cooling fluid. Is configured to control.

In some embodiments, the pre-chamber is connected to the first opening through a channel extending along a first axis, and an angle between the first axis and a reference plane arranged perpendicular to the center axis Is between 0 and 85 degrees, between 0 and 80 degrees, between 0 and 60 degrees, between 0 and 45 degrees, or between 0 and 30 degrees.

As a result, the flame extending from the pre-chamber into the cylinder can be in direct contact with a large portion of the mixture of scavenger air and fuel gas.

In some embodiments, the engine further comprises a second pre-chamber arranged at least partially in the cylinder wall, the second pre-chamber opening into the cylinder through a second opening formed in the cylinder wall.

The second pre-chamber may be the same as the above-described pre-chamber, for example, the second pre-chamber may have a pilot fuel valve, a pre-chamber cooling system, or the like.

The second pre-chamber can be arranged opposite to the first pre-chamber.

The engine may have more pre-chambers, for example at least three or four pre-chambers per cylinder.

According to a second aspect, the present invention relates to a pre-chamber member for a cylinder for a crosshead internal combustion engine as disclosed in relation to the first aspect, wherein the pre-chamber member has a cylinder wall, the pre-chamber The member further comprises a pre-chamber arranged at least partially in the cylinder wall, the pre-chamber opening into the pre-chamber member through a first opening formed in the cylinder wall, the pre-chamber It is configured to ignite a mixture of scavenger air and fuel gas.

Different aspects of the present invention can be implemented in different ways, including a two-stroke uniflow scavenging crosshead internal combustion engine and a pre-chamber member, as described above and as below, each of the aspects described above. One or more preferred embodiments corresponding to the preferred embodiments described in connection with at least one of the aspects disclosed above and/or in the dependent claims, yielding one or more advantages and advantages described in connection with at least one of Have forms. Furthermore, it will be appreciated that the embodiments described in connection with one of the aspects described herein can be equally applied to the other aspect.

There are always two angles between two axes, between two planes, or between one axis and one plane: a small angle (V1) and a large angle (V2) (where V2 = 180 degrees-V1). The angle specified in this specification is always a small angle (V1).

According to the present invention, by providing a pre-chamber on the cylinder wall, the mixture of scavenger air and fuel gas in the cylinder can be ignited effectively without occupying the space of the cylinder cover.

By providing a pre-chamber in the cylinder wall, greater flexibility is obtained for arranging the essential components in the cylinder cover, and also components such as an exhaust valve can be expanded. Furthermore, it will be possible to arrange several pre-chambers around the cylinder wall.

With regard to the actual combustion process, the pre-chamber arranged in the cylinder wall offers the advantage of facilitating the ignition of the fuel gas close to the inner wall. If the pre-chamber is arranged on the cylinder wall, the flame is oriented more horizontally, so that the flame can come into contact with a large part of the scavenger air and fuel gas mixture.

Furthermore, arranging the pre-chamber on the cylinder wall ensures that the pre-chamber temperature is not affected by the temperature of the cylinder cover, e.g., more effectively cooling the pre-chamber by differentiating the pre-chamber temperature over the load range of the engine. I can make it.

The above and/or additional objects, features and advantages of the present invention will be further explained by the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the accompanying drawings.
1 schematically shows a cross-section of a two-stroke internal combustion engine according to an embodiment of the present invention.
2 shows a schematic cross-sectional view of a part of a two-stroke crosshead internal combustion engine with uniflow scavenging according to an embodiment of the present invention.
3 shows a schematic cross-sectional view of a part of a two-stroke crosshead internal combustion engine with uniflow scavenging according to an embodiment of the present invention.
4 shows a schematic diagram of a pre-chamber according to an embodiment of the present invention.
5 schematically shows a cross-sectional view of a two-stroke internal combustion engine according to an embodiment of the present invention.

In the description that follows, reference is made to the accompanying drawings, which show by way of example how the present invention may be practiced.

FIG. 1 is a diagram of a large low-speed turbocharged two-stroke crosshead internal combustion engine (also simply referred to as'engine') 100 with uniflow scavenging for propulsion of a marine vessel according to an embodiment of the present invention. The cross section is schematically shown. The engine 100 includes a scavenger air system 111, an exhaust gas receiver 108, a fuel gas supply system, and a turbocharger 109. The engine has a plurality of cylinders 101 (only one cylinder is shown in the cross section). Each cylinder 101 has a cylinder wall 115 and includes a scavenger air inlet 102 arranged at the bottom of the cylinder 101. The engine further includes a cylinder cover 112 and a piston 103 for each cylinder. The cylinder cover 112 is arranged on top of the cylinder 101 and has an exhaust valve 104. The piston 103 is arranged to be movable in the cylinder along the central axis 113 between the bottom dead center and the top dead center. The fuel gas supply system includes one or more fuel gas valves 105 (shown schematically only) configured to inject fuel gas into the cylinder 101 during the compression stroke so that the fuel gas can be mixed with the scavenger air. And allow the mixture of scavenge air and fuel gas to be compressed before ignition. The fuel gas valve 105 is arranged at least partially within the cylinder wall between the cylinder cover 112 and the scavenge air inlet 102. The engine further comprises a pre-chamber 114 arranged at least partially within the cylinder wall 115, the pre-chamber 114 being opened into the cylinder through a first opening formed in the cylinder wall, the pre-chamber being a cylinder It is configured to ignite a mixture of scavenger air and fuel gas within 101. The scavenger air inlet 102 is fluidly connected to the scavenger air system. The piston 103 is shown in its lowest position (bottom dead center). The piston 103 has a piston rod connected to a crankshaft (not shown). The fuel gas valve 105 is configured to inject fuel gas into the cylinder during the compression stroke, allowing the fuel gas to be mixed with the scavenger air and allowing the mixture of scavenger air and fuel gas to be compressed prior to ignition. The fuel gas valve 105 injects fuel gas into the cylinder 101 at the start of the compression stroke of 0 degrees to 130 degrees from the bottom dead center, that is, when the crankshaft rotates from 0 degrees to 130 degrees from the orientation at the bottom dead center. Is configured to Preferably, the fuel gas valve 105 has the crankshaft shaft several degrees from the bottom dead center so that the piston moves past the scavenger air inlet 102 to prevent the fuel gas from being discharged through the exhaust valve 104. It is configured to start injection of fuel gas after rotation. The scavenging air system 111 includes a scavenging air receiver 110 and an air cooler 106.

The engine 100 is preferably a dual-fuel engine having an auto cycle mode driven by fuel gas and a diesel cycle mode driven by alternative fuels such as heavy oil or marine diesel oil. These dual-fuel engines have a dedicated alternative fuel supply system for injecting alternative fuels. Thus, optionally, engine 100 further comprises one or more fuel injectors 116 arranged within cylinder cover 112 forming part of an alternative fuel supply system. When the engine 100 is driven with an alternative fuel, the fuel injector 116 is configured to inject an alternative fuel such as heavy oil, for example, at the end of the high pressure compression stroke.

2 shows a schematic cross-sectional view of a part of a two-stroke crosshead internal combustion engine with uniflow scavenging according to an embodiment of the present invention. A cylinder 101, a cylinder cover 112, a piston 103, and an exhaust valve 104 are shown. The piston 103 is located at the top dead center. The cylinder 101 has a cylinder wall 115 provided with a first pre-chamber 114 and a second pre-chamber 116. The first and second pre-chambers 114 and 116 are opened into the cylinder 101 through an opening formed in the cylinder wall 115, and the pre-chambers 114 and 116 are It is configured to ignite the mixture. The engine preferably further comprises a pilot fuel supply system comprising a first pilot fuel valve arranged in the first pre-chamber 114 and a second pilot fuel valve arranged in the second pre-chamber 116, The first and second pilot fuel valves are configured to inject pilot fuel into the pre-chamber. The pilot fuel supply system may be configured to inject a predetermined amount of pilot fuel at the end of the compression stroke through the first and second pilot fuel valves. The pilot fuel can be ignited immediately after being injected by the temperature and pressure in the pre-chamber. This makes it possible to precisely control the ignition timing of the mixture of scavenger air and fuel gas in the cylinder 101.

3 shows a schematic cross-sectional view of a part of a two-stroke crosshead internal combustion engine with uniflow scavenging according to an embodiment of the present invention. The part of Fig. 3 corresponds to the part shown in Fig. 2, but the cylinder 101 has a base member 117 and a pre-chamber member 118, and the pre-chamber member 118 is of the base member 117. It is arranged on the top, and the cylinder cover 112 is different in that it is arranged on the top of the pre-chamber member 118. The first and second pre-chambers 114 and 116 are arranged in the cylinder wall of the pre-chamber member 118. This allows the pre-chamber member to be designed to handle particularly high temperatures and pressures, for example by selecting an appropriate material.

4 shows a schematic diagram of a pre-chamber 114 according to an embodiment of the present invention. The pre-chamber 114 is configured to open into the cylinder through the first opening 123 and the second opening 124. The pre-chamber includes an ignition element 119 and a pilot fuel valve 120, which injects pilot fuel gas into the pre-chamber during the compression stroke so that the pilot fuel gas 121 can be compressed before being ignited. Is configured to The ignition element 119 is configured to ignite the pilot fuel gas in the pre-chamber to create a flame 122 for igniting the fuel gas in the cylinder.

5 is a cross-sectional view of a large low speed turbocharged two-stroke crosshead internal combustion engine with uniflow scavenging for propulsion of a marine vessel according to an embodiment of the present invention. The engine is a dual-fuel engine having an auto cycle mode driven by fuel gas and a diesel cycle mode driven by alternative fuels such as heavy oil or marine diesel oil. Each cylinder has a cylinder wall and includes a scavenger air inlet arranged at the bottom of the cylinder (not shown). The engine further includes a cylinder cover 112 and a piston 103 for each cylinder. The cylinder cover 112 is arranged on the top of the cylinder and has an exhaust valve 104. The piston 103 is arranged to be movable in the cylinder along the central axis between the bottom dead center and the top dead center. The fuel gas supply system includes one or more fuel gas valves (not shown) configured to inject fuel gas into the cylinders during the compression stroke (when the engine is in gas mode i.e. auto cycle mode), so that the fuel gas is mixed with scavenging air. And allow the mixture of scavenge air and fuel gas to be compressed before ignition. The fuel gas valve is arranged at least partially within the cylinder wall between the cylinder cover 112 and the scavenger air inlet. The engine further includes two pilot pre-chamber units 131, and each pilot pre-chamber unit 131 includes a pre-chamber 114, a pilot fuel valve housing 130, and the pilot fuel valve housing ( It includes a pilot fuel valve 132 arranged in 130). The cylinder has a base member 117 and a pre-chamber member 118, the pre-chamber member 118 is arranged on top of the base member 117 and the cylinder cover 112 is of the pre-chamber member 118. Are arranged at the top. The pre-chamber 114 is arranged in the cylinder wall of the pre-chamber member 118. The pre-chamber 114 is opened into the cylinder through an opening formed in the cylinder wall of the pre-chamber member 118. The scavenger air inlet is fluidly connected to the scavenger air system. The piston 103 is connected to a crankshaft (not shown) through a piston rod, a crosshead, and a connecting rod. The pilot fuel valve 132 is configured to inject a small amount of pilot fuel into the pre-chamber 114 (when the engine is in gas mode). The pre-chamber 114 is configured to self-ignite the pilot fuel due to the temperature and pressure in the pre-chamber 114. The pilot fuel oil may be heavy oil, marine diesel oil, or any other fuel with suitable self-igniting properties.

The engine further includes one or more fuel injectors 116 arranged in a cylinder cover 112 that forms part of an alternative fuel supply system. When the engine 100 is driven with an alternative fuel, the fuel injector 116 is configured to inject an alternative fuel such as heavy oil, for example, at the end of the high pressure compression stroke.

The pre-chamber 114 is arranged in the cylinder wall, thus taking up less space within the cylinder cover 112. This allows the size of the exhaust valve 104 and the number/size of alternative fuel injectors 116 to be less limited. Furthermore, by providing a cylinder with a pre-chamber member 118, the pre-chamber member 118 can be made of a stronger material compared to the base member of the cylinder 117, whereby the cylinder is created by ignition. It may require less, or even not at all, external supports, such as a strong back, to handle the resulting forces. Moreover, the pre-chamber member 118 is a fuel injector 116 for dual-fuel and even tri-fuel engines as well as several separate pre-chambers 114 (e.g., three or four). To be arranged around the cylinder wall of the pre-chamber member 118.

Further, by arranging the pre-chamber in the cylinder wall, at least a portion of the pilot fuel valve housing 130 and the pilot fuel valve 132 can be arranged outside of other engine components, thereby lowering the cooling demand. Finally, by arranging the pre-chamber 114 within the cylinder wall, more space is provided for a cooling element, such as the cooling channel 135 shown in the figure.

While some embodiments have been described and illustrated in detail, the invention is not limited to these, and may be implemented in other ways within the scope of the subject matter defined in the claims that follow. In particular, it should be understood that other embodiments may be used and structural and functional modifications may be made without departing from the scope of the present invention.

In the device claim enumerating several means, some of these means may be implemented by one and the same hardware item. The fact that certain measures are cited in different dependent claims or described in different embodiments does not indicate that a combination of these measures cannot be used to advantage.

The term "comprises/comprising", as used herein, is taken to specify the presence of a recited feature, integer, step, or element, but one or more other features. It should be emphasized that it does not exclude the presence or addition of, integers, steps, elements or groups thereof.

Embodiment

1. A two-stroke uniflow scavenging crosshead internal combustion engine comprising at least one cylinder, a cylinder cover, a piston, a fuel gas supply system, and a scavenging air system, wherein the cylinder has a cylinder wall, and the cylinder cover is a cylinder Is arranged at the top of and has an exhaust valve, the piston is arranged to be movable in the cylinder along a central axis between the bottom dead center and the top dead center, and the scavenger air system has a scavenger air inlet arranged at the bottom of the cylinder, The fuel gas supply system includes a fuel gas valve arranged at least partially on the cylinder wall and configured to inject fuel gas into the cylinder during the compression stroke so that the fuel gas can be mixed with the scavenger air and a mixture of scavenger air and fuel gas. Allowing it to be compressed before being ignited, wherein the engine further comprises a pre-chamber arranged at least partially in the cylinder wall, the pre-chamber opening into the cylinder through a first opening formed in the cylinder wall Wherein the pre-chamber is configured to ignite a mixture of scavenger air and fuel gas within the cylinder.

2. A two-stroke crosshead internal combustion engine according to Embodiment 1, further comprising a pilot fuel supply system, wherein the pilot fuel supply system includes a pilot fuel valve arranged in the pre-chamber, the pilot fuel valve A two-stroke crosshead internal combustion engine configured to inject pilot fuel into the pre-chamber.

3. A two-stroke crosshead internal combustion engine according to embodiment 1 or 2, wherein at least one of the cylinders has a base member and a pre-chamber member, the pre-chamber member being arranged above the base member and the cylinder A cover is arranged on top of the pre-chamber member, the pre-chamber member is at least partially arranged on the cylinder wall of the pre-chamber member, and the pre-chamber is formed on the cylinder wall of the pre-chamber member. A two-stroke crosshead internal combustion engine that opens into the cylinder through an opening.

4. A two-stroke crosshead internal combustion engine according to embodiment 3, wherein the pre-chamber member of the cylinder is made of a different material than the base member of the cylinder.

5. A two-stroke crosshead internal combustion engine according to any one of embodiments 1 to 4, further comprising a pre-chamber cooling system for cooling the pre-chamber, wherein the pre-chamber cooling system And a cooling channel proximate the pre-chamber to extract heat from the pre-chamber, wherein the pre-chamber cooling system is configured to circulate cooling fluid through the cooling channel.

6. A two-stroke crosshead internal combustion engine according to embodiment 5, wherein the pre-chamber cooling system further comprises a control unit configured to control the flow of the cooling fluid and/or the inlet temperature of the cooling fluid. Crosshead internal combustion engine.

7. A two-stroke crosshead internal combustion engine according to embodiment 6, wherein the control unit comprises: a cooling fluid according to an engine load, an engine speed, and/or an air-fuel equivalent ratio (λ) of a mixture of scavenger air and fuel gas A two-stroke crosshead internal combustion engine configured to control the flow of and/or the inlet temperature of the cooling fluid.

8. A two-stroke crosshead internal combustion engine according to any one of embodiments 1 to 7, wherein the pre-chamber is connected to the first opening through a channel extending along the first axis, and perpendicular to the center axis. The two-stroke crosshead internal combustion engine, wherein the angle between the reference plane arranged as and the first axis is between 0° and 80°, between 0° and 60°, between 0° and 45°, or between 0° and 30° .

9. A two-stroke crosshead internal combustion engine according to any one of embodiments 1 to 8, wherein the engine further comprises a second pre-chamber arranged at least partially on the cylinder wall, the second pre-chamber A two-stroke crosshead internal combustion engine that opens into the cylinder through a second opening formed in the cylinder wall.

10. A two-stroke crosshead internal combustion engine according to any one of embodiments 1 to 9, wherein the pre-chamber member has a cylinder wall, and the pre-chamber member is at least partially arranged on the cylinder wall. Further comprising a chamber, wherein the pre-chamber is opened into the pre-chamber member through a first opening formed in the cylinder wall, and the pre-chamber is configured to ignite a mixture of scavenger air and fuel gas, 2-stroke crosshead internal combustion engine.

100: 2-stroke uniflow scavenging crosshead internal combustion engine (also simply referred to as'engine'), 101: cylinder, 102: scavenging air inlet, 103: piston, 104: exhaust valve, 105: fuel gas valve, 111: scavenging Air system, 112: cylinder cover, 113: central axis, 114: pre-chamber, 115: cylinder wall, 116: second pre-chamber, 117: base member, 118: pre-chamber member, 120: pilot fuel valve.

Claims (8)

A two-stroke uniflow scavenging crosshead internal combustion engine 100 comprising at least one cylinder 101, a cylinder cover 112, a piston 103, a fuel gas supply system, and a scavenging air system 111,
The cylinder 101 has a cylinder wall 115, the cylinder cover 112 is arranged above the cylinder 101 and has an exhaust valve 104, and the piston 103 is between the bottom dead center and the top dead center. It is arranged to be movable in the cylinder 101 along the central axis 113, the scavenge air system has a scavenger air inlet 102 arranged at the bottom of the cylinder 101, the fuel gas supply system is a cylinder Includes a fuel gas valve 105 arranged at least partially on the wall 115 and configured to inject fuel gas into the cylinder 101 during the compression stroke so that the fuel gas can be mixed with the scavenger air and the scavenger air and the fuel gas Allowing the mixture of to be compressed before being ignited,
In the two-stroke uniflow scavenging crosshead internal combustion engine,
The engine includes a pre-chamber 114 configured to ignite a mixture of scavenger air and fuel gas in the cylinder 101, and at least one of the cylinders 101 includes a base member 117 and a pre-chamber. Having a member 118, the pre-chamber member 118 is arranged on the top of the base member 117 and the cylinder cover 112 is arranged on the top of the pre-chamber member 118,
The pre-chamber 114 is at least partially arranged on the cylinder wall of the pre-chamber member 118, and the pre-chamber is into the cylinder 101 through an opening formed in the cylinder wall of the pre-chamber member. A two-stroke uniflow scavenging crosshead internal combustion engine, characterized in that opening. The method according to claim 1,
Further comprising a pilot fuel supply system,
The pilot fuel supply system includes a pilot fuel valve 120 arranged in the pre-chamber, and the pilot fuel valve is configured to inject pilot fuel into the pre-chamber 114, a two-stroke uniflow scavenging system. Type crosshead internal combustion engine. The method according to claim 1,
The pre-chamber member (118) of the cylinder is made of a different material than the base member (117) of the cylinder, a two-stroke uniflow scavenging crosshead internal combustion engine. The method according to any one of claims 1 to 3,
Further comprising a pre-chamber cooling system for cooling the pre-chamber,
The pre-chamber cooling system includes a cooling channel proximate to the pre-chamber to extract heat from the pre-chamber, the pre-chamber cooling system configured to circulate a cooling fluid through the cooling channel. , 2-stroke uniflow scavenging crosshead internal combustion engine. The method of claim 4,
The pre-chamber cooling system further comprises a control unit configured to control the flow of the cooling fluid and/or the inlet temperature of the cooling fluid. The method of claim 5,
The control unit is configured to control the flow of the cooling fluid and/or the inlet temperature of the cooling fluid according to the engine load, the engine speed, and/or the air-fuel equivalent ratio (λ) of the mixture of scavenge air and fuel gas, 2-stroke uniflow scavenging crosshead internal combustion engine. The method according to any one of claims 1 to 6,
The pre-chamber 114 is connected to the opening through a channel extending along a first axis line, and an angle between a reference plane arranged perpendicular to the center axis 113 and the first axis line is 0 A two-stroke uniflow scavenging crosshead internal combustion engine between 80 and 80 degrees, between 0 and 60, between 0 and 45, or between 0 and 30 degrees. The method according to any one of claims 1 to 7,
The engine further comprises a second pre-chamber 116 arranged at least partially in the cylinder wall 115,
The second pre-chamber (116) is opened into the cylinder through a second opening formed in the cylinder wall (115), a two-stroke uniflow scavenging crosshead internal combustion engine.

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