A fuel valve for injecting fuel into the cylinders of a large turbocharged two-stroke direct-scavenging internal combustion engine, and an engine having such a fuel valve.

Abstract

A fuel valve (30) for injecting liquid fuel into the combustion chamber of a large two-stroke turbocharged direct-scavenging internal combustion engine with a crosshead, and a large two-stroke turbocharged direct-scavenging internal combustion engine with such a fuel valve. The fuel valve (30) uses a resiliently biased valve member (35) that is amplified by the fuel pressure supplied to the fuel valve (30), and the valve member is configured to perform pilot fuel injection or main fuel injection using a hydraulic control system that uses fuel as the hydraulic medium and is controlled by an electronic control valve that determines whether to perform pilot injection or main injection when the externally supplied fuel pressure increases to perform an injection event.

Description

Technical Field

[0001] This disclosure relates to a fuel valve for injecting liquid fuel into the cylinder of a large turbocharged two-stroke direct-flow scavenging internal combustion engine, and an engine having such a fuel valve. Background Technology

[0002] Large turbocharged two-stroke DC scavenging crosshead internal combustion engines are typically used as prime movers for large ocean-going vessels, such as container ships or power plants.

[0003] These engines are equipped with a single exhaust valve in each cylinder, centrally located in the cylinder head, i.e., at the top of the cylinder. This single exhaust valve also has a piston-controlled scavenging port in the lower region of the cylinder liner. Therefore, the gas is always delivered from bottom to top through the cylinder, hence the term "direct scavenging." The scavenging port is angled to create a vortex in the gas within the combustion chamber.

[0004] Two or three fuel valves are arranged in the cylinder head around a centrally located exhaust valve, with the fuel valve nozzles extending into the combustion chamber. Fuel valves are also arranged peripherally (i.e., not centrally) in the cylinder head, with the nozzle orifice generally designed to move away from the cylinder wall and into the combustion chamber with the swirl. Sometimes, a single nozzle orifice is oriented towards the swirl in the combustion chamber.

[0005] The nozzle is attached to the front or rear end of the fuel valve. The fuel valve includes an elongated housing, wherein a proximal or rear end protrudes from the upper surface of the cylinder head, and wherein the elongated fuel valve housing extends through the cylinder head, and wherein the nozzle extends into the combustion chamber at the front or rear end of the elongated fuel valve housing.

[0006] Known nozzles for large, crosshead-type two-stroke diesel engines typically have a nozzle body comprising a cylindrical section, wherein a straight main orifice extends from the base of the nozzle at the proximal end of the nozzle body to a nozzle orifice near the tip or distal end of the nozzle body. The tip or distal end can be rounded or flat, but it is closed because the nozzle orifice cannot point downwards toward the piston (when the piston is at top dead center, i.e., at the moment of fuel injection in a compression-ignition engine, the upper surface of the piston is very close to the tip of the nozzle). Typically, each nozzle has three to seven nozzle orifices, all connected to the main orifice. Fuel valves capable of exhibiting both main injection and pilot injection typically have one or two additional, smaller pilot nozzle orifices, also connected to the main orifice. These valves typically have a movable valve member, and the pilot nozzle orifice typically opens with a smaller lift of the movable valve member, while both the pilot nozzle orifice and the main nozzle orifice open with a larger lift of the movable valve member.

[0007] Typically, known fuel valves for injecting liquid fuels are equipped with an axially displaceable valve needle that cooperates with a conical valve seat to control the fuel flow toward the nozzle. Furthermore, the forward section of the valve needle includes a distal cylindrical member that is tightly received within the main bore and acts as a spool valve to close the nozzle orifice when the valve needle is in the closed position, thereby significantly reducing the so-called needle valve pressure chamber volume (SAC volume), i.e., significantly reducing the residual fuel capacity in the space formed by the main bore in the nozzle. Without this spool valve arrangement, the residual fuel capacity in the main bore (and nozzle orifice) drips into the combustion chamber after the fuel injection event, adversely affecting fuel consumption, reliability, and emissions.

[0008] KR102057802 discloses a fuel valve for a dual-fuel engine, comprising: a valve body including: a fuel passage through which fuel is supplied; a main injection orifice communicating with the fuel passage; and a pilot injection orifice; and a valve portion having a single valve needle resiliently supported and movable within the valve body, the valve portion selectively opening and closing the main injection orifice and the pilot injection orifice according to a fuel supply mode. The movement distance of the valve portion is determined by pressure applied within the valve body. When the fuel supply mode is diesel mode, the valve needle simultaneously opens the main injection orifice and the pilot injection orifice; and when the fuel supply mode is gas mode, the valve needle opens only the pilot injection orifice. The stroke limiting only to pilot injection is achieved by applying high-pressure hydraulic oil to a displaceable stop plunger in the fuel valve. Therefore, this known fuel valve, in addition to being connected to the fuel supply system, also needs to be connected to a high-pressure hydraulic system. This necessitates that the engine be equipped with such a hydraulic system, and that each of the three or four fuel valves in the cylinder be connected to the high-pressure hydraulic system via a double-walled conduit. Each fuel valve is also connected to a valve block that includes a hydraulic valve capable of handling high-pressure hydraulic fluid. In such valves, it is necessary to ensure that the hydraulic fluid does not mix with the fuel, or vice versa. Therefore, measures such as seals or pressure barriers are required in the fuel valve to prevent this contamination. These requirements make the fuel valve itself more expensive, increase the engine cost due to the required additional equipment, and reduce reliability due to the constant risk of fuel and hydraulic fluid mixing.

[0009] US4285471A discloses a fuel injection nozzle for an internal combustion engine, comprising: a nozzle body having a first set of fuel injection openings and a fuel inlet device for applying pressurized fuel to the first set of injection openings; a slidable valve needle in the nozzle body; means for applying a closing force to the valve needle, the valve needle being opened against the closing force to move the valve needle into a closed relationship with the first set of injection openings; a control piston slidably disposed in the nozzle body for acting on the valve needle at a side; a spring chamber in the nozzle body; an inlet device in the nozzle body for applying pressurized control fluid from an associated fluid pressure source in the spring chamber facing the valve needle to the control piston; and means for controlling the pressure of the control fluid independently of fuel discharged from the fuel injection nozzle through the first set of injection openings. Summary of the Invention

[0010] In view of the above, the object of the present invention is to provide a fuel valve for injecting liquid fuel into a large two-stroke direct-flow scavenging internal combustion engine of the crosshead type, which overcomes or at least reduces the problems mentioned above.

[0011] The foregoing and other objectives are achieved through features of various aspects of the invention. Further implementations are apparent according to other aspects and the accompanying drawings.

[0012] According to a first aspect, a fuel valve is provided for injecting liquid fuel into the combustion chamber of a large two-stroke turbocharged direct-flow scavenging internal combustion engine having a crosshead, the fuel valve comprising:

[0013] - Fuel inlet port,

[0014] - Fuel control port,

[0015] - One or more main nozzle orifices,

[0016] - One or more pilot nozzle orifices,

[0017] - A valve component that is movable between a closed position and an open position, and that has an intermediate position between the closed and open positions.

[0018] The valve member is elastically biased towards the closed position and is hydraulically pushed towards the open position by the fuel pressure acting on the first surface of the valve member through the fuel inlet port.

[0019] Specifically, when the valve component is in the closed position, it shuts off the fuel flow to one or more main nozzle orifices and also shuts off the fuel flow to one or more pilot nozzle orifices.

[0020] When the valve component is in the intermediate position, it shuts off the fuel flow to one or more main nozzle orifices and connects the fuel flow to one or more pilot nozzle orifices.

[0021] Specifically, when the valve component is in the open position, it enables the fuel flow to one or more main nozzle orifices and enables the fuel flow to one or more pilot nozzle orifices.

[0022] - A device for selectively blocking the displacement of a valve component from the intermediate position to the open position.

[0023] The device includes:

[0024] - A blocking member having a second surface exposed to the fuel pressure in the first fuel chamber.

[0025] - An electronically controlled valve, preferably a solenoid valve, having at least a first position and a second position, configured to:

[0026] - In the first position, the electronically controlled valve ensures that fuel pressure exists in the first fuel chamber at the fuel supply port, and

[0027] - In the second position, the electronically controlled valve ensures that fuel pressure at the fuel control port exists in the first fuel chamber.

[0028] The blocking member is capable of shifting between a blocking position and a non-blocking position. In the blocking position, the blocking member blocks the movement of the valve member from the intermediate position to the open position; in the non-blocking position, the blocking member does not block the movement of the valve member from the intermediate position to the open position.

[0029] The blocking member is configured as follows:

[0030] - When fuel pressure exists in the first fuel chamber at the fuel supply port, the blocking member is moved to the blocking position, and

[0031] - When fuel pressure exists in the first fuel chamber at the fuel control port, move the blocking member to the non-blocking position.

[0032] The fuel valve allows for precise control over the injection of pilot and main fuel into the combustion chamber of a large, two-stroke, turbocharged, direct-scavenging internal combustion engine with a crosshead. This ensures optimal fuel-air mixing and combustion efficiency, thereby improving engine performance and reducing emissions.

[0033] The device for selectively blocking the displacement of valve components provides enhanced control over the fuel injection process. By blocking the movement of the valve components from the intermediate position to the closed position, the fuel valve is able to deliver accurate pilot injections (small amounts), thereby ensuring accurate timing and duration of fuel injection.

[0034] The electronically controlled valve (preferably a solenoid valve) allows for rapid and precise switching between a first position and a second position (i.e., between pilot injection and average injection). This enables a seamless transition between pilot injection and main injection, thus contributing to efficient fuel injection control.

[0035] The fuel valve uses fuel solely as the pressure medium for achieving the lifting of the valve member / pin, and is used in devices that open the valve member to a position enabling pilot injection through a small pilot nozzle opening or injection through a larger main nozzle opening. Since fuel is the only hydraulic medium, there is no risk of mixing with another pressure medium (e.g., hydraulic oil). This significantly reduces the need for measures to prevent mixing of fuel and hydraulic oil, thus greatly simplifying the construction required to create a barrier between the two pressure media. Furthermore, the fuel valve does not require an external control valve for actuation, double-walled hydraulic tubing for the hydraulic medium, a hydraulic control block associated with the hydraulic medium, or internal seals, media detection, or components specifically designed for hydraulic oil. Therefore, the fuel valve itself and its installation in the engine are significantly simplified. It only requires cable connections for installation, without a hydraulic control valve or double-walled tubing for the hydraulic medium.

[0036] The resilient bias of the fuel valve toward the closed position ensures that the valve components remain shut off from fuel flow to the main nozzle orifice and pilot nozzle orifice when not in use. This prevents fuel leakage and potential safety hazards.

[0037] The valve assembly is hydraulically pushed to the open position by the fuel pressure at the fuel inlet port, allowing for a smooth and controlled opening of the valve. This ensures a continuous and reliable flow of fuel to the main nozzle orifice and pilot nozzle orifice during operation.

[0038] The ability of the valve assembly to connect fuel flow to both the main nozzle orifice and the pilot nozzle orifice in the open position, as well as to connect fuel flow to only the pilot nozzle orifice, provides flexibility in fuel injection strategy. This capability allows the fuel injection valve to be used solely for pilot injection, for example, when the main fuel is a different fuel (dual-fuel engine), such as natural gas, which is delivered to the combustion chamber via a separate fuel valve specifically designed to deliver the other (main) fuel. This allows for optimization of combustion characteristics based on engine operating conditions, thereby improving performance and fuel efficiency.

[0039] In a possible implementation of the first aspect, the first fuel chamber is permanently connected to the fuel inlet port via a conduit including a flow restrictor, and wherein an electronically controlled valve, in a second position, connects the first fuel chamber to the fuel control port.

[0040] The fluid connection between the first fuel chamber and the fuel inlet port, as well as the fluid connection between the first fuel chamber and the fuel control port, ensures efficient fuel supply and control. This eliminates the need for additional fuel lines or connections, thereby simplifying fuel valve design and reducing potential points of failure.

[0041] A permanent connection between the first fuel chamber and the fuel inlet port via a pipe including a flow restrictor allows the pressure in the first fuel chamber to be changed to the pressure at the fuel control port by opening the pipe that establishes a fluid connection with the fluid control port, since the flow restrictor will limit the flow from the fuel supply port to the first fuel chamber, and therefore the flow from the fuel supply port is insufficient to maintain the pressure at the fuel supply port in the first fuel chamber.

[0042] The electronically controlled valve's ability to connect the first fuel chamber to the fuel control port in the second position provides precise control over the fuel pressure in the first fuel chamber. This allows the fuel valve's operation to be adjusted for either pilot injection or main injection.

[0043] In a possible implementation of the first aspect, the electronically controlled valve connects the first fuel chamber to the fuel inlet port in a first position, and connects the first fuel chamber to the fuel control port in a second position.

[0044] The electronically controlled valve's ability to connect the first fuel chamber to the fuel inlet port in the first position ensures that the pressure in the first fuel chamber corresponds to the pressure in the supply port. This causes the pressure in the fuel supply port to move the blocking member to a position where it restricts the valve member from moving to the intermediate position and also blocks the valve member from moving to the open position.

[0045] The electronically controlled valve's ability to connect the first fuel chamber to the fuel control port in the second position ensures that the pressure in the first fuel chamber corresponds to the pressure in the fuel control port. This ensures that the pressure in the first fuel chamber corresponds to the pressure in the fuel control port. Because the pressure in the fuel control port is selected differently, preferably lower than the pressure in the fuel supply port, this causes the blocking member to move to a position that does not obstruct the valve member from shifting to the open position, thereby allowing the main nozzle opening to open.

[0046] The dimensional difference between the first surface of the valve member and the second surface of the blocking member ensures that the blocking member reliably moves to the blocking position. This prevents the valve member from being lifted to the open position when fuel pressure is present in the first fuel chamber at the fuel supply port, thus ensuring pilot injection.

[0047] In a possible implementation of the first aspect, the size of the first surface of the valve member is smaller than the size of the second surface of the blocking member.

[0048] The fuel valve's ability to selectively block the movement of its valve members from the intermediate position to the closed position provides control over the fuel valve's operating mode, i.e., control over pilot injection or main injection. This allows the fuel valve to function as a pilot fuel valve for ignition of auxiliary main fuel, which is delivered by a separate fuel valve dedicated to delivering the main fuel, and it also allows the fuel valve to function as a main fuel valve for liquid fuels. Therefore, this fuel valve is particularly suitable for dual-fuel engines, where it can be used for both liquid fuel injection and main liquid fuel injection.

[0049] The movement of the blocking member to the blocking position when fuel pressure exists in the first fuel chamber at the fuel supply port ensures reliable blocking of the valve member.

[0050] The movement of the blocking member to the non-blocking position when fuel pressure is present in the first fuel chamber at the fuel control port allows for unblocked displacement of the valve member.

[0051] In a possible implementation of the first aspect, the blocking member includes a plunger received in a bore in a close-fitting manner, the blocking member having a third surface arranged opposite to the second surface, and wherein the valve member has a fourth surface opposite to the first surface and opposite to the third surface.

[0052] The tight fit between the plunger and the bore of the blocking member ensures a safe and reliable blocking position, thus preventing any leakage or accidental movement.

[0053] The arrangement of the third surface on the blocking member and the fourth surface on the valve member allows for precise and stable abutment when the blocking member is in the blocking position and the valve member is in the intermediate position, thereby ensuring the normal operation of the valve system.

[0054] In the open and intermediate positions, the lifting of the movable valve component due to the valve seat allows for controlled movement of the liquid fuel flow.

[0055] In a possible implementation of the first aspect, the fourth surface is adjacent to the third surface when the blocking member is in the blocking position and the valve member is in the intermediate position.

[0056] Attaching the base of the nozzle body to the distal end of the fuel valve provides a safe and stable connection, thereby minimizing the risk of detachment or leakage during operation.

[0057] In a possible implementation of the first aspect, the movable valve member rests on the valve seat in the closed position, and the movable valve member has a lift due to the valve seat in the open position and intermediate position.

[0058] The use of a plunger that is received in a hole in the blocking member in a tight fit ensures a safe and reliable blocking position, thereby preventing any leakage or accidental movement.

[0059] The arrangement of the third surface on the blocking member and the fourth surface on the valve member allows for precise and stable abutment when the blocking member is in the blocking position and the valve member is in the intermediate position, thereby ensuring the proper functioning of the fuel valve.

[0060] In a possible implementation of the first aspect, the nozzle includes a nozzle body that extends along a longitudinal axis from a base located at a proximal end of the nozzle body to a closed distal end of the nozzle body, preferably with the base attached to the distal end of the fuel valve.

[0061] Attaching the base of the nozzle body to the distal end of the fuel valve provides a safe and stable connection, thereby minimizing the risk of detachment or leakage during operation.

[0062] In a possible implementation of the first aspect, the nozzle body includes:

[0063] The elongated portion, preferably a cylindrical portion, extends between the base and the closed distal end.

[0064] The inlet opens to a base for receiving liquid fuel from a fuel valve.

[0065] A single straight main orifice extends longitudinally from the inlet into the nozzle body.

[0066] The tight fit between the plunger and the bore of the blocking member ensures a safe and reliable blocking position, thus preventing any leakage or accidental movement.

[0067] The arrangement of the third surface on the blocking member and the fourth surface on the valve member allows for precise and stable abutment when the blocking member is in the blocking position and the valve member is in the intermediate position, thereby ensuring the normal operation of the valve system.

[0068] In a possible implementation of the first aspect, the displaceable valve member includes a distal section having a cylindrical end section supported by a rod-like member, and the distal section is fitted tightly into a straight main bore to:

[0069] When the movable valve component is in the closed position, the main nozzle orifice is fluidly disconnected from the straight main orifice, and the pilot nozzle orifice is fluidly disconnected from the straight main orifice.

[0070] When the movable valve component is in the intermediate position, the main nozzle orifice is fluidly disconnected from the straight main orifice, and the pilot nozzle orifice is fluidly connected to the straight main orifice.

[0071] When the movable valve component is in the open position, the main nozzle orifice is fluidly connected to the straight main orifice and the pilot nozzle orifice is fluidly connected to the straight main orifice.

[0072] In a possible implementation of the first aspect, the end section of the cylindrical member is hollow to form a fluid channel, preferably opening proximally to the outside of the rod-shaped member, and preferably opening distally in the axial direction.

[0073] In one possible implementation of the first aspect, the cross-sectional area of ​​the pilot nozzle orifice is smaller than that of the main nozzle orifice.

[0074] In a possible implementation of the first aspect, the main nozzle orifice and / or the pilot nozzle orifice are holes.

[0075] In a possible implementation of the first aspect, the main nozzle orifice and the pilot nozzle orifice are connected to the main orifice at axially spaced locations.

[0076] - Because the main nozzle orifice and the pilot nozzle orifice can be adjusted independently, this configuration allows for precise control of fluid flow through the nozzle system.

[0077] - By connecting the main nozzle orifice and the pilot nozzle orifice at axially spaced positions, the degree of lifting of the valve component is determined as either no spraying, spraying only through the pilot nozzle orifice, or spraying through both the pilot nozzle orifice and the main nozzle orifice.

[0078] In a possible implementation of the first aspect, the displaceable valve member includes a distal section having a cylindrical end section carried by a rod-like member, and the distal section is fitted into a straight main bore in a close-fitting manner.

[0079] - The tight fit between the end section of the cylindrical component and the main bore ensures a safe and reliable connection, thereby preventing any fluid leakage or loss during operation.

[0080] This design also allows for smooth and precise movement of the movable valve components, thereby ensuring accurate control of fluid flow through the nozzle system.

[0081] In a possible implementation of the first aspect, the end section of the cylindrical member is hollow to form a fluid channel, preferably opening proximally to the outside of the rod-shaped member, and preferably opening distally in the axial direction.

[0082] - The hollow cylindrical end section provides a dedicated fluid channel that allows for efficient and controlled fluid flow through the nozzle system.

[0083] - By opening the fluid passage to the outside of the rod at the proximal end and opening the fluid passage axially at the distal end, the fluid can be precisely guided to the desired location, thereby enhancing the overall performance and functionality of the nozzle system.

[0084] In one possible implementation of the first aspect, the cross-sectional area of ​​the pilot nozzle orifice is smaller than that of the main nozzle orifice.

[0085] This configuration allows for precise control of small fuel flows via pilot injection through the nozzle system, as the pilot nozzle orifice has a smaller cross-sectional area compared to the main nozzle orifice, thus limiting the flow.

[0086] - By making the pilot nozzle orifice and the main nozzle orifice have different cross-sectional areas, the fuel flow rate can be selected, thus providing flexibility and versatility in a variety of applications (especially in dual-fuel engines).

[0087] In a possible implementation of the first aspect, the main nozzle orifice and / or the pilot nozzle orifice are holes.

[0088] Using orifices for the main nozzle orifice and / or pilot nozzle orifice ensures that fluid flows smoothly and consistently through the nozzle system.

[0089] - Orifice-based nozzles also provide better control over flow characteristics, resulting in more accurate and efficient operation of the nozzle system.

[0090] In a possible implementation of the first aspect, the main nozzle orifice and the pilot nozzle orifice are connected to the main orifice at axially spaced locations.

[0091] - By connecting the main nozzle orifice and the pilot nozzle orifice at axially spaced positions, the size of the fuel flow used for pilot injection or main injection can be selected.

[0092] In a possible implementation of the first aspect, the displaceable valve member includes a distal section having a cylindrical end section carried by a rod-like member, and the distal section is fitted into a straight main bore in a close-fitting manner.

[0093] - The tight fit between the end section of the cylindrical component and the main bore ensures safe and reliable operation, thereby preventing any fluid leakage or loss during operation.

[0094] This design also allows for smooth and precise movement of the movable valve components, thereby ensuring accurate control of fluid flow through the nozzle system.

[0095] In a possible implementation of the first aspect, the end section of the cylindrical member is hollow to form a fluid channel, preferably opening proximally to the outside of the rod-shaped member, and preferably opening distally in the axial direction.

[0096] - The hollow cylindrical end section provides a dedicated fluid channel that allows for efficient and controlled fluid flow through the nozzle system.

[0097] - By opening the fluid passage to the outside of the rod at the proximal end and opening the fluid passage axially at the distal end, the fluid can be precisely guided to the desired location.

[0098] In a possible embodiment of the first aspect, the valve member is a valve needle that is slidably received in a longitudinal bore of an elongated valve body. The displaceable valve member rests on a valve seat in the closed position, and the valve needle has a lift due to the valve seat in the open and intermediate positions.

[0099] Using a valve needle as a valve component allows for precise control of fuel flow in the engine, as the valve needle can be easily adjusted to change the lift caused by the valve seat in the open and intermediate positions.

[0100] By placing the valve seat and / or fuel chamber within an elongated valve body, the overall size and complexity of the fuel injection system can be reduced, thereby saving manufacturing and maintenance costs.

[0101] Ensuring that all main nozzle orifices have approximately equal main cross-sectional areas or diameters, and preferably also approximately equal lengths, promotes a uniform distribution of fuel flow across the nozzle orifices, thereby improving engine performance and efficiency.

[0102] In one possible implementation of the first aspect, the valve seat and / or fuel chamber are disposed within an elongated valve body.

[0103] In a possible implementation of the first aspect, all the main nozzle holes have approximately equal main cross-sectional areas or diameters, and preferably, all the main nozzle holes also have approximately equal lengths.

[0104] In a possible implementation of the first aspect, the main nozzle orifice and / or the pilot nozzle orifice are open to the surface of the elongated portion, preferably, the elongated portion is a cylindrical portion.

[0105] In a possible implementation of the first aspect, the electronically controlled valve is a spool valve, preferably a sliding spool valve, and more preferably a sliding spool type solenoid valve.

[0106] In a possible implementation of the first aspect, the fuel valve includes a preferably rounded transition surface between the generally cylindrical portion of the nozzle body and the flat distal end surface.

[0107] In a possible implementation of the first aspect, all straight nozzle orifices have a nozzle axis, wherein the nozzle axis of each nozzle orifice is arranged at an obtuse angle α with the main direction X.

[0108] In a possible implementation of the first aspect, the radial component of each nozzle axis relative to the longitudinal axis (X) is distributed on a circular sector with an arc of less than 120 deg, preferably the radial component of each nozzle axis relative to the longitudinal axis (X) is distributed approximately uniformly on a circular sector with an arc of less than 120 deg.

[0109] According to a second aspect, a large two-stroke turbocharged direct-scavenging internal combustion engine with a crosshead is provided, the large two-stroke turbocharged direct-scavenging internal combustion engine including a fuel valve according to the first aspect and any possible implementation thereof.

[0110] These and other aspects of the invention will become apparent from the embodiments described below. Attached Figure Description

[0111] In the following detailed sections of this disclosure, the invention will be explained in more detail with reference to exemplary embodiments shown in the accompanying drawings, in which:

[0112] Figure 1 This is a front end and a lateral side view of a large two-stroke unit flow scavenging turbocharged engine according to an exemplary embodiment.

[0113] Figure 2 yes Figure 1 An elevation view of the rear end and another transverse side of the engine;

[0114] Figure 3 It is based on Figure 1 A schematic diagram of an engine with an intake system and an exhaust system;

[0115] Figure 4 It is used in Figures 1 to 3 A cross-sectional view of an embodiment of a fuel valve used in an engine prior to a fuel injection event, wherein the valve component is in the closed position;

[0116] Figure 5 yes Figure 4 A cross-sectional view of the fuel valve during fuel injection, wherein the valve component is in the open position and the blocking component is in the unblocking position;

[0117] Figure 6 yes Figure 4 A more detailed cross-sectional view of the nozzle of the fuel valve in the image;

[0118] Figure 7 yes Figure 5 A more detailed cross-sectional view of the nozzle of the fuel valve in the image;

[0119] Figure 8 It shows the time before the fuel injection event. Figure 4 The fuel valve in the system, wherein the valve component is in the closed position;

[0120] Figure 9 yes Figure 4 A cross-sectional view of the fuel valve during fuel injection, wherein the valve component is in the open position and the blocking component is in the blocking position;

[0121] Figure 10 yes Figure 8 A more detailed cross-sectional view of the nozzle of the fuel valve in the image;

[0122] Figure 11 yes Figure 9 A more detailed cross-sectional view of the nozzle of the fuel valve in the image;

[0123] Figure 12 yes Figure 4 An elevation view of the tip of the nozzle of the fuel valve in the middle;

[0124] Figure 13 and Figure 14 yes Figure 12 A transparent view of the tip of the nozzle; and

[0125] Figure 15 Viewed from the side of the piston Figure 4 A schematic diagram showing the location of the fuel valve nozzle in the engine cylinder head, and illustrating the nozzle orifice and the resulting orientation of fuel injection. Detailed Implementation

[0126] In the following detailed description, a fuel valve and a large two-stroke engine using the fuel valve will be described by way of exemplary embodiments. Figures 1 to 3 A large, low-speed turbocharged two-stroke internal combustion engine with a crankshaft 22 and a crosshead 23 is shown. Figure 3A schematic diagram of a large, low-speed turbocharged two-stroke internal combustion engine with an intake and exhaust system is shown. In this exemplary embodiment, the engine has six cylinders (formed by cylinder liners 1) in line. Large turbocharged two-stroke internal combustion engines typically have five to sixteen cylinders in line, which are carried by an engine frame 24. For example, this engine can be used as the main engine of an ocean-going vessel or as a stationary engine for operating generators in a power plant. The total output of the engine can be, for example, in the range of 5,000 kW to 110,000 kW.

[0127] The engine can be a two-stroke, direct-flow diesel (compression ignition) engine, having a scavenging port 19 in the form of an annular piston-controlled port in the lower region of the cylinder liner 1 and an exhaust valve 4 at the top of the cylinder liner 1. Therefore, the flow in the combustion chamber is always from bottom to top, and thus the engine is so-called direct-flow. Scavenging air is delivered from the scavenging air receiver 2 to the scavenging air ports 19 of the individual cylinders formed by the cylinder liner 1. The reciprocating piston 21 in the cylinder liner 1 compresses the scavenging air; fuel is injected via nozzles of two or three fuel valves 30 arranged in the cylinder head 26. Combustion then occurs, producing exhaust gases. When the exhaust valve 4 is open, the exhaust gases flow through the exhaust pipe 20 associated with the relevant cylinder 1 to the exhaust gas receiver 3, and then proceed through the first exhaust pipe 18 to the turbine 6 of the turbocharger 5, from which the exhaust gases flow away through the turbine 6 via the second exhaust pipe 7. The turbine 6 drives the compressor 9 via the shaft 8, which is supplied with air via the air inlet 10.

[0128] Compressor 9 delivers pressurized charging air to charging air line 11 leading to charging air receiver 2. Scavenging air in line 11 passes through intercooler 12 for cooling the charging air. The cooled charging air is then delivered via auxiliary blower 16 driven by electric motor 17. Under low or partial load conditions, auxiliary blower 16 pressurizes the charging air flow to charging air receiver 2. Under higher load conditions, turbocharger compressor 9 delivers sufficient compressed scavenging air, and then auxiliary blower 16 is bypassed via check valve 15.

[0129] The cylinder is formed in the cylinder liner 1. The cylinder liner 1 is supported by the cylinder frame 25, which is supported by the engine frame 24.

[0130] Figure 15 This illustrates how the nozzle 40 is positioned within the cylinder head 26 around the periphery of the exhaust valve 4, and Figure 15The direction of fuel injection is shown (corresponding to the directions of axes I, II, III, IV, and V of the main nozzle orifices 45 in nozzle 40). Typically, there are at least four main nozzle orifices 45 and typically one or two pilot nozzle orifices 46. The direction of fuel injection from the pilot nozzle orifices 46 is similar to the direction of fuel injection from the main nozzle orifices 45. Typically, each cylinder is provided with three (as shown) or four fuel valves 30. In a dual-fuel engine, there will be an additional three or four fuel valves (not shown) for injecting other fuels; when the other fuel valves are engaged, this fuel valve 30 is used only for pilot fuel injection. When no other fuel is used, this fuel valve 30 is used for main fuel injection. The direction of the gas vortex in the combustion chamber is indicated by the curved dashed arrow 96. The cross-sectional area of ​​the pilot nozzle orifice 46 is smaller than that of the main nozzle orifice 45, and the number of pilot nozzle orifices 46 is typically less than the number of main nozzle orifices 45. Therefore, at a given fuel injection pressure, the amount of fuel injected solely through the pilot nozzle orifices 46 is significantly less than the amount injected through the combined pilot nozzle orifices 46 and main nozzle orifices 45. Preferably, all main nozzle orifices in the main nozzle orifices 45 have substantially equal main cross-sectional areas or diameters and preferably also substantially equal lengths. Similarly, all pilot nozzle orifices in the pilot nozzle orifices 46 preferably have substantially equal pilot cross-sectional areas or diameters and preferably also substantially equal lengths. The main cross-sectional area or diameter of the main nozzle orifice 45 is larger than that of the pilot cross-sectional area or diameter of the pilot nozzle orifice 46.

[0131] Figures 4 to 11 An embodiment with two to four fuel valves 30 is shown, which are installed in a through hole in the cylinder head 26 of each cylinder, wherein the rear end 31 of the fuel valve 30 protrudes from the upper side of the cylinder head 26, and wherein the distal end (tip) of the nozzle 40 protrudes slightly into the combustion chamber.

[0132] Figures 12 to 14 The distal end of nozzle 40 is shown in more detail.

[0133] Fuel valve 30 includes an elongated fuel valve body 32 having a nozzle 40 at its distal end (front end) 33. Liquid fuel (e.g., ethanol, methanol, diesel, heavy fuel oil) is delivered by fuel valve 30 to combustion chamber 14 via nozzle 40 in a controlled and timed manner. Fuel valve 30 has an elongated body 32 with a head at its proximal end 31, through which fuel valve 30 can be mounted in cylinder head 26 in a known manner and connected to a fuel pump (not shown) of the internal combustion engine. When a fuel injection event begins, the fuel pump increases the fuel pressure, and when the fuel injection event ends, the fuel pump decreases the pressure. Typical maximum fuel injection pressure is above 200 bar, preferably above 300 bar.

[0134] The head at the proximal end 31 includes a fuel inlet port 83, which is fluidly connected to a conduit 62 extending through the valve body 32. An axially displaceable valve member 35 (preferably a valve needle) is mounted in the valve housing 32 and has: an open position, in which the valve member 35 has a lift due to a preferably tapered valve seat 36; an intermediate position, in which the valve member 35 also has a lift due to the seat 36; and a closed position, in which the mating section of the valve member 35 rests in a sealing manner on the valve seat 36. The valve needle is elastically biased toward the closed position by an elastic device, in this embodiment, formed by a coil spring 87. The lift of the valve needle 35 over the bias of the coil spring 87 is caused by the pressure of fuel supplied to the fuel supply port 83 acting on a first surface of the valve member 35. In this embodiment, the pressure in the second fuel chamber 68 acts on the first surface of the valve member 35 to orient the valve member 35 toward the open position.

[0135] The fuel valve 30 carries the nozzle 40 at its distal end 33. The nozzle 40 is configured to extend into the combustion chamber 14 of the engine cylinder liner 1 through five nozzle holes 46 or through both the pilot nozzle hole 46 and the main nozzle hole 45.

[0136] In this embodiment, the fuel valve 30 includes a needle-shaped, axially movable valve member 35. The valve member 35 includes a tapered section that engages with a tapered seat 36 within the longitudinal body 32 of the fuel valve 30. The valve seat 36 opens into a second fuel chamber 68 surrounding the axial portion of the valve member 35 and housing a helical spring 87. A fuel conduit 62 connects a fuel inlet port 83 to the second fuel chamber 68.

[0137] A fuel control port 85, open to the surface of the body of fuel valve 30 (preferably near its rear or proximal end), receives a reference fuel pressure or a control fuel pressure (via connection to a substantially constant fuel pressure source). In this embodiment, the control fuel pressure is lower than the pressure of the fuel supplied to the fuel inlet port 83 during a fuel injection event. The fuel control port 85 is connected to the first fuel chamber 81 via an electronically controlled valve 60. Preferably, the electronically controlled valve 60 is a solenoid valve having at least two positions, preferably an open or closed position, and the electronically controlled valve 60 is controlled by an electronic control unit (not shown) of the engine. Preferably, the electronically controlled valve 60 is a spool valve, more preferably a sliding spool valve, and even more preferably, a sliding spool type solenoid valve.

[0138] The first fuel chamber 81 is connected to the fuel inlet port 83 via a conduit 67 including a limiting device 64 (e.g., in the form of an orifice or other suitable device) to ensure that the flow from the fuel inlet port 83 to the first fuel chamber 81 is relatively small compared to the fuel flow from the fuel control port 85 to the first fuel chamber 81 when the electronically controlled valve 60 is in the open position. A movable blocking member 80 in the form of a plunger is received in a bore in the valve body 32 in a close-fitting manner to allow the movable blocking member 80 to axially displace between a blocking position and an unblocking position. The first fuel chamber 81 is formed in the bore in the valve body, and the blocking member has a second (axially facing) surface exposed to the fuel pressure in the first fuel chamber 81. Opposite to the second surface, the blocking member has a reduced-diameter section received in a matching bore in the valve body 32 to limit the stroke of the blocking member 80 in the direction toward the nozzle 40, and the reduced-diameter section of the blocking member 80 is provided with a third surface arranged opposite to the second surface. The valve member 35 has a fourth surface at its nearest end, which is arranged opposite to the first surface and opposite to the third surface. The size of the first surface of the valve member 35 is smaller than the size of the third surface of the blocking member 80; therefore, when both the first and third surfaces are exposed to equal pressure, the force of the blocking member 80 in the closing direction is greater than the force of the valve member 35 in the opening direction. When the blocking member 80 is in the blocking position and the valve member 35 is in the intermediate position, the fourth surface is adjacent to the third surface, such as... Figure 9 As shown, this prevents the valve component 35 from moving from the intermediate position to the open position.

[0139] The electronically controlled valve 60 is configured such that, when in the closed position, it allows fuel pressure at the fuel supply port 83 to exist in the first fuel chamber 81, and when in the open position, it allows fuel pressure at the fuel control port 85 to exist in the first fuel chamber 81. The blocking member 80 is movable between a blocking position and a non-blocking position. In the blocking position, the blocking member 80 blocks the movement of the valve member 35 from the intermediate position to the open position; in the non-blocking position, the blocking member 80 does not block the movement of the valve member 35 from the intermediate position to the open position. When fuel pressure at the fuel supply port 83 exists in the first fuel chamber 81, i.e., when the electronically controlled valve 60 is open, the blocking member 80 moves to... Figure 9 The blocking position is shown, and when fuel pressure is present in the first fuel chamber 81 at the fuel control port 85, i.e., when the electronically controlled valve 60 is closed, the blocking member 80 can move freely to the non-blocking position. In this case, the fourth surface abuts the third surface, thereby preventing the valve member 35 from moving further in the direction toward the open position.

[0140] Figures 12 to 14 The distal end section of the valve needle 35 and the nozzle 40 are shown in more detail.

[0141] The nozzle 40 has a nozzle body that extends along a longitudinal axis (X) from a base 42 located at a proximal end 41 to a closed distal end 44, which forms the tip of the nozzle 40. A cylindrical portion 43 of the nozzle body extends from the base to the distal end 44. The nozzle body is made of a suitable material, for example, a suitable alloy well known in the art.

[0142] When the valve needle 35 is in the intermediate or open position, the inlet 48 opens toward the base 42, which receives liquid fuel from the fuel valve 30. A straight main orifice 50 extends longitudinally from the inlet 48 into the nozzle body. The closed distal end (tip) 44 includes a generally flat end surface 47 having a circular or elliptical profile. The end surface 47 connects to the cylindrical portion via a curved or rounded transition surface 49.

[0143] The nozzle 40 is provided with a plurality of main nozzle holes 45 (typically three to seven main nozzle holes 45) and one or more pilot nozzle holes 46 (typically two). Preferably, the main nozzle holes 45 are straight main nozzle holes; preferably, the pilot nozzle holes 46 are straight pilot nozzle holes 46.

[0144] When the fuel valve 30 is in the open position, each main nozzle orifice 45 opens towards the outer surface of the nozzle body 43 at a different radial angle, so that the fuel ray fans out (e.g., ...). Figure 14 (As shown) is injected into the combustion chamber. Each main nozzle orifice 45 opens to the outer surface of the nozzle body at a different radial angle. Preferably, the main nozzle orifice 45 opens to the cylindrical surface 43 and / or the transition surface 49. Similarly, the pilot nozzle orifice 46 opens to the cylindrical surface 43 and / or the transition surface 49 at an appropriate radial angle.

[0145] The base 42 is provided with an inlet port 48 for receiving fuel from the fuel valve body 32. A main bore 50 extends from the inlet port 48 into the nozzle body and along the main axis X into the cylindrical portion 43, reaching a position near the distal end 44 of the nozzle body. The distal end 44 is located in the nozzle body at a distance from the distal end of the main bore 50. The main bore 50 connects to a main nozzle orifice 45 at a first axial distance from the distal end 44 and to a pilot nozzle orifice 46 at a second axial distance from the distal end 44. The second axial distance is smaller than the first axial distance, allowing flow from the main bore 50 to the pilot nozzle orifice 46 with a small lift / small axial displacement of the valve member 35 in the open position direction, whereas flow from the main bore 50 to the main nozzle orifice 46 is only permitted with a large lift or large axial displacement of the valve member 35 in the direction toward the open position. Figure 14 Compared to the shorter double arrows, Figure 13 The longer double arrows in the middle indicate the difference in lifting between the valve component 35 and its cylindrical portion 39, wherein, Figure 13 The valve component 35 is shown in the open position, and Figure 14 The valve component 35 is shown in the middle position.

[0146] The valve needle 35 includes a distal section comprising a cylindrical end section 39 carried by a shank 38. The cylindrical end section 39 is hollow to form a fluid passage 71 for fuel transfer from the proximal side of the cylindrical end section 39 to its distal side. The fluid passage 71 opens proximally to the outside of the shank 38 and distally in an axial direction.

[0147] The end section 39 of the cylindrical component is fitted tightly into the straight main bore 50 so that when the valve needle 35 is in the closed position, the pilot nozzle orifice 46 is fluidly disconnected from the straight main bore 50, and the main nozzle orifice 45 is fluidly disconnected from the straight main bore 50. Figure 4 , Figure 6 and Figure 10As shown, when the valve needle 35 is in the closed position, the end section 39 of the cylindrical member covers the openings of the pilot nozzle orifice 46 and the main nozzle orifice 45 leading to the main bore 50. Therefore, when the valve member 35 is in the closed position, any fuel leakage into the combustion chamber 14 can be prevented from the space between the valve seat 36 and the distal end of the main bore 50.

[0148] When the valve member 35 is in the intermediate position, the lifting / axial movement toward the open position of the valve member causes the cylindrical portion 39 to cover only the opening of the main nozzle orifice 45 leading to the main bore, thereby allowing fuel to be injected into the combustion chamber through the pilot nozzle orifice 46, but not through the main nozzle orifice 45. Figure 9 and Figure 11 As shown.

[0149] When the valve component 35 is in the open position, the cylindrical end section 39 fluidly connects the opening of the pilot nozzle orifice 46 to the straight main orifice 50 and fluidly connects the opening of the main nozzle orifice 45 to the straight main orifice 50, as shown below. Figure 5 and Figure 7 As shown, by ensuring that the end section 39 of the cylindrical member does not cover the opening of any of the nozzle holes 45, 46 facing the straight main hole 50, fuel is allowed to be injected into the combustion chamber through both the pilot nozzle hole 46 and the main nozzle hole 45 to perform the main fuel injection event.

[0150] In an embodiment of fuel valve 30 (not shown), the electronically controlled valve 60 connects the first fuel chamber 81 to the fuel inlet port 83 in the first position, and connects the first fuel chamber 81 to the fuel control port 85 in the second position, without restricting the fluid connection between the fuel inlet port and the first pressure chamber.

[0151] The invention has been described in conjunction with various embodiments herein. However, those skilled in the art, upon practicing the claimed invention, will understand and implement other variations of the disclosed embodiments by studying the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. The mere fact that certain measures are described in mutually different dependent claims does not indicate that combinations of these measures cannot be fully utilized. The reference numerals used in the claims should not be construed as limiting the scope.

Claims

1. A fuel valve (30) for injecting liquid fuel into the combustion chamber of a large two-stroke turbocharged direct-scavenging internal combustion engine having a crosshead, said fuel valve (30) comprising: - Fuel inlet port (83). - Fuel control port (85) - One or more main nozzle holes (45). - One or more pilot nozzle orifices (46). - A valve component (35) capable of shifting between a closed position and an open position, and having an intermediate position between the closed position and the open position. The valve member (35) is elastically biased toward the closed position and is hydraulically pushed toward the open position by the fuel pressure acting on the first surface of the valve member (35) through the fuel inlet port (83). In the closed position, the valve component (35) shuts off the fuel flow to one or more of the main nozzle orifices (45) and the fuel flow to one or more of the pilot nozzle orifices (46). When the valve component (35) is in the intermediate position, it shuts off the fuel flow to one or more of the main nozzle orifices (45) and turns on the fuel flow to one or more of the pilot nozzle orifices (46). In the open position, the valve component (35) enables the fuel flow to one or more of the main nozzle orifices (45) and the fuel flow to one or more of the pilot nozzle orifices (46). Its features - A means for selectively blocking the displacement of the valve member (35) from the intermediate position to the open position. The device includes: - A blocking member (80), which is separate from the valve member (35), the blocking member (80) having a second surface exposed to the fuel pressure in the first fuel chamber (81), - An electronically controlled valve (60) having at least a first position and a second position, the electronically controlled valve (60) being configured to: - In the first position, the electronically controlled valve (60) ensures that fuel pressure exists in the first fuel chamber (81) at the fuel inlet port (83), and - In the second position, the electronically controlled valve (60) ensures that the fuel pressure at the fuel control port (85) exists in the first fuel chamber (81). The blocking member (80) is movable between a blocking position and a non-blocking position. In the blocking position, the blocking member (80) blocks the movement of the valve member (35) from the intermediate position to the open position. In the non-blocking position, the blocking member (80) does not block the movement of the valve member (35) from the intermediate position to the open position. Wherein, the size of the first surface of the valve member (35) is smaller than the size of the second surface of the blocking member (80). The blocking member (80) is configured as follows: - When fuel pressure exists in the first fuel chamber (81) at the fuel inlet port (83), the blocking member (80) is moved to the blocking position, and - When the fuel pressure at the fuel control port (85) is present in the first fuel chamber (81), the blocking member (80) is moved to the non-blocking position.

2. The fuel valve (30) according to claim 1, wherein, The first fuel chamber (81) is fluidly connected to the fuel inlet port (83) and the fuel control port (85).

3. The fuel valve (30) according to claim 1 or 2, wherein, The first fuel chamber (81) is permanently connected to the fuel inlet port (83) via a pipe (67) including a flow restrictor (64), and wherein the electronically controlled valve (60) in the second position connects the first fuel chamber (81) to the fuel control port (85).

4. The fuel valve (30) according to claim 1, wherein, When the electronically controlled valve (60) is in the first position, it connects the first fuel chamber (81) to the fuel inlet port (83), and when the electronically controlled valve (60) is in the second position, it connects the first fuel chamber (81) to the fuel control port (85).

5. The fuel valve (30) according to claim 1, wherein, The blocking member (80) includes a plunger received in a hole in a tight fit, the blocking member (80) has a third surface arranged opposite to the second surface, and wherein the valve member (35) has a fourth surface opposite to the first surface and opposite to the third surface.

6. The fuel valve (30) according to claim 5, wherein, When the blocking member (80) is in the blocking position and the valve member (35) is in the intermediate position, the fourth surface is adjacent to the third surface.

7. The fuel valve (30) according to claim 6, wherein, The valve member (35) rests on the valve seat (36) in the closed position, and the valve member (35) has a lift due to the valve seat (36) in the open position and the intermediate position.

8. The fuel valve (30) according to claim 1, wherein the fuel valve (30) comprises an elongated fuel valve body (32) having a longitudinal axis (X), the elongated fuel valve body (32) having a proximal end (31) and a distal end (33), wherein, A nozzle (40) is provided at the distal end (33) of the elongated fuel valve body (32).

9. The fuel valve (30) according to claim 8, wherein, The nozzle (40) includes a nozzle body that extends along the longitudinal axis (X) from a base (42) located at the proximal end (41) of the nozzle body to a closed distal end (44) of the nozzle body, the base (42) being attached to the distal end of the fuel valve (30).

10. The fuel valve (30) according to claim 9, wherein, The nozzle body includes: An elongated portion (43) extends between the base (42) and the closed distal end (44). Inlet (48), which opens toward base (42), which is used to receive liquid fuel from fuel valve (30), and A single straight main hole (50) extends longitudinally from the inlet (48) into the nozzle body.

11. The fuel valve (30) according to claim 10, wherein, The main nozzle hole (45) and the pilot nozzle hole (46) are connected to the main hole (50) at axially spaced positions.

12. The fuel valve (30) according to claim 10, wherein, The valve component (35) includes a distal section having a cylindrical end section (39) supported by a rod-like member (38), and the distal section is fitted into the straight main bore (50) in a close-fitting manner, so as to: When the valve component (35) is in the closed position, the main nozzle orifice (45) is fluidly disconnected from the straight main orifice (50) and the main nozzle orifice (45) is fluidly disconnected from the pilot nozzle orifice (46). When the valve component (35) is in the intermediate position, the main nozzle orifice (45) is fluidly disconnected from the straight main orifice (50) and the pilot nozzle orifice (46) is fluidly connected to the straight main orifice (50). When the valve component (35) is in the open position, the main nozzle orifice (45) is fluidly connected to the straight main orifice (50) and the pilot nozzle orifice (46) is fluidly connected to the straight main orifice (50).

13. The fuel valve (30) according to claim 12, wherein, The end section (39) of the cylindrical member is hollow to form a fluid channel (71), which opens proximally to the outside of the rod (38) and opens distally in an axial manner.

14. The fuel valve (30) according to claim 1. in, The cross-sectional area of ​​the pilot nozzle orifice (46) is smaller than that of the main nozzle orifice (45).

15. The fuel valve (30) according to claim 1, wherein, The main nozzle hole (45) and the pilot nozzle hole (46) are holes.

16. The fuel valve (30) according to claim 8, wherein, The valve member (35) is a valve needle that is slidably received in a longitudinal hole in the elongated fuel valve body (32). The valve member (35) rests on the valve seat (36) in the closed position and has a lift due to the valve seat (36) in the open position and the intermediate position.

17. The fuel valve (30) according to claim 16, the fuel valve (30) comprising a second fuel chamber (68) surrounding an axial portion of the valve member (35) and opening toward the valve seat (36).

18. The fuel valve (30) according to claim 16, wherein, The valve seat (36) is disposed in the elongated fuel valve body (32).

19. The fuel valve (30) according to claim 17, wherein, The valve seat (36) and the second fuel chamber (68) are disposed in the elongated fuel valve body (32), or the second fuel chamber (68) is disposed in the elongated fuel valve body (32).

20. The fuel valve (30) according to claim 1, wherein, All the main nozzle holes in the main nozzle holes (45) have one or more of the following: equal main cross-sectional areas, equal main cross-sectional diameters, and equal lengths.

21. The fuel valve (30) according to claim 1, wherein, All pilot nozzle holes (46) have one or more of the following: equal cross-sectional area, equal cross-sectional diameter, and equal length.

22. The fuel valve (30) according to claim 20, wherein, The main nozzle orifice has an equal main cross-sectional area or diameter that is larger than the pilot nozzle orifice's equal cross-sectional area or diameter.

23. The fuel valve (30) according to claim 10, wherein, The main nozzle orifice (45) and / or the pilot nozzle orifice (46) are open to the surface of the elongated portion (43).

24. The fuel valve (30) according to claim 1, wherein, The electronically controlled valve (60) is a slide valve.

25. The fuel valve (30) according to claim 24, wherein, The electronically controlled valve (60) is a sliding valve.

26. The fuel valve (30) according to claim 24, wherein, The electronically controlled valve (60) is a sliding solenoid valve.

27. A large two-stroke turbocharged direct-scavenging internal combustion engine with a crosshead, the large two-stroke turbocharged direct-scavenging internal combustion engine comprising a fuel valve (30) according to any one of claims 1 to 26.

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