Fuel valve for injecting fuel into cylinder of large turbocharged two-stroke uniflow scavenging internal combustion engine and engine having such fuel valve

Abstract

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

Description

Technical Field

[0001] The present disclosure relates to a fuel valve for injecting liquid fuel into the cylinders of a large turbocharged two-stroke uniflow-scavenged internal combustion engine and an engine having such a fuel valve. Background Art

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

[0003] The cylinders of these engines are equipped with a single discharge valve which is placed centrally in the cylinder head, i.e. at the top of the cylinder, and which is equipped with a circle of piston-controlled scavenge ports at the lower area of ​​the cylinder liner. The direction of delivery of the gases through the cylinder is therefore always from bottom to top, hence the term direct scavenging. The scavenge ports are inclined to create a swirl in the gases in the combustion chamber.

[0004] Two or three fuel valves are arranged in the cylinder head around a centrally placed discharge valve, wherein the nozzles of the fuel valves protrude into the combustion chamber. The fuel valves are arranged peripherally (i.e. not centrally) in the cylinder head, wherein the nozzle bores of the nozzles are generally directed away from the cylinder wall and into the combustion chamber with the vortex. Sometimes, a single nozzle bore of the nozzle is directed toward the vortex in the combustion chamber.

[0005] The nozzle is attached to the front end or the distal end of the fuel valve. The fuel valve includes an elongated housing, wherein the proximal end or the 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 protrudes into the combustion chamber at the front end or the distal end of the elongated fuel valve housing.

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

[0007] Typically, known fuel valves for injecting liquid fuels are provided with an axially displaceable valve needle which cooperates with a conical valve seat for controlling the fuel flow to the nozzle. In addition, the forward section of the valve needle comprises a distal cylindrical piece which is tightly received in the main bore and which acts as a slide valve for shutting off the nozzle bore when the valve needle is in the closed position, thereby significantly reducing the so-called sac volume, i.e. the residual fuel volume in the space formed by the main bore in the nozzle. Without such a slide valve arrangement, the residual fuel volume in the main bore (and the nozzle bore) would drip into the combustion chamber after the fuel injection event has been completed, which has an adverse effect on fuel consumption, reliability and emissions.

[0008] KR102057802 discloses a fuel valve for a dual-fuel engine, the fuel valve comprising: a valve body, the valve body comprising: a fuel channel, the fuel is supplied through the fuel channel; a main injection hole, the main injection hole is connected to the fuel channel; and a pilot injection hole; a valve part, the valve part has a single valve needle, the single valve needle is elastically supported in the valve body and moves in the valve body, and the valve part selectively turns on and off the main injection hole and the pilot injection hole according to the fuel supply mode. The moving distance of the valve part is determined by the pressure applied to the inside of the valve body. When the fuel supply mode is the diesel mode, the valve needle turns on the main injection hole and the pilot injection hole at the same time; and when the fuel supply mode is the gas mode, the valve needle turns on only the pilot injection hole. The stroke that limits only the pilot injection is obtained by applying high-pressure hydraulic oil to the displaceable blocking plunger in the fuel valve. Therefore, this known fuel valve needs to be connected to a high-pressure hydraulic system in addition to the fuel supply system, and therefore requires that the engine be provided with such a hydraulic system, and that each of the three or four fuel valves of the cylinder is connected to the high-pressure hydraulic system via a double-walled pipe, and each fuel valve is connected to a valve block comprising a hydraulic valve that can handle the high-pressure hydraulic oil. In such valves, it is necessary to ensure that the hydraulic oil does not mix with the fuel or that the fuel does not mix with the hydraulic oil, and therefore, it is necessary to provide measures against such contamination in the fuel valve, such as seals or pressure barriers. These requirements make the fuel valve itself more expensive, the engine more expensive due to the need for additional equipment, and its reliability is lower due to the constant risk of mixing of fuel and hydraulic oil.

[0009] US4285471A discloses a fuel injection nozzle for an internal combustion engine, which includes: a nozzle body having a first group of fuel injection openings and a fuel inlet device, the fuel inlet device being used to apply pressurized fuel to the first group of injection openings; a slidable valve needle in the nozzle body; a device for applying a closing force to the valve needle, the valve needle being opened against the closing force so that the valve needle moves into a closed relationship with the first group of injection openings; a control piston, which is slidably arranged in the nozzle body and is used to act on the valve needle at one side; a spring chamber in the nozzle body; an inlet device in the nozzle body, the inlet device being used to apply pressurized control fluid from a related fluid pressure source on the side of the spring chamber facing the valve needle to the control piston; and a device for controlling the pressure of the control fluid independently of the fuel discharged from the fuel injection nozzle through the first group of injection openings. Summary of the invention

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

[0011] The above and other objects are achieved by the features of the independent claims. Further implementations are evident from the dependent claims, the description and the drawings.

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

[0013] - fuel inlet port,

[0014] -Fuel control port,

[0015] - one or more main nozzle holes,

[0016] - one or more pilot nozzle holes,

[0017] - a valve member displaceable between a closed position and an open position, and

[0018] The valve member has an intermediate position between a closed position and an open position,

[0019] wherein the valve member is resiliently biased toward a closed position and hydraulically urged toward an open position by fuel pressure from a fuel inlet port acting on a first surface of the valve member,

[0020] wherein the valve member shuts off fuel flow to one or more main nozzle holes and shuts off fuel flow to one or more pilot nozzle holes in the closed position,

[0021] wherein the valve member shuts off the fuel flow to one or more main nozzle holes and switches on the fuel flow to one or more pilot nozzle holes when in the intermediate position,

[0022] wherein the valve member, in the open position, enables fuel flow to one or more main nozzle holes and enables fuel flow to one or more pilot nozzle holes,

[0023] - means for selectively blocking displacement of the valve member from the intermediate position to the open position,

[0024] The device comprises:

[0025] a blocking member having a second surface exposed to the fuel pressure in the first fuel chamber,

[0026] - an electronically controlled valve, preferably, the electronically controlled valve is a solenoid valve, the electronically controlled valve has at least a first position and a second position, the electronically controlled valve is configured to:

[0027] - in the first position, the electronically controlled valve causes fuel pressure from the fuel supply port to be present in the first fuel chamber, and

[0028] - in the second position, the electronically controlled valve causes the fuel pressure of the fuel control port to be present in the first fuel chamber,

[0029] The blocking member is displaceable between a blocking position and a non-blocking position, wherein the blocking member blocks the displacement of the valve member from the intermediate position to the open position, and the non-blocking position does not block the displacement of the valve member from the intermediate position to the open position.

[0030] Wherein, the blocking member is configured as follows:

[0031] - moving the blocking member to the blocking position when the fuel pressure of the fuel supply port is present in the first fuel chamber, and

[0032] - moving the blocking member to the non-blocking position when fuel pressure from the fuel control port is present in the first fuel chamber.

[0033] The fuel valve allows precise control of the injection of pilot and main fuel into the combustion chamber of large two-stroke turbocharged uniflow-scavenged internal combustion engines with crosshead. This ensures optimum fuel-air mixing and combustion efficiency, resulting in improved engine performance and reduced emissions.

[0034] The device for selectively blocking the displacement of the valve member provides enhanced control of the fuel injection process. By blocking the movement of the valve member from the intermediate position to the closed position, the fuel valve can deliver an accurate pilot injection (a small amount), thereby ensuring accurate timing and duration of fuel injection.

[0035] The electronically controlled valve (preferably, the electronically controlled valve is a solenoid valve) allows fast and precise switching between the first position and the second position (i.e., between the pilot injection and the average injection). This enables a seamless transition between the pilot injection only and the main injection, thereby facilitating efficient fuel injection control.

[0036] The fuel valve uses fuel only as a pressure medium for obtaining the lift of the valve member / valve needle, and uses fuel for the following device: the device opens the valve member to a position that can provide only a pilot injection through a smaller pilot nozzle opening or a position that provides injection through a larger main nozzle opening. Since the fuel is the only hydraulic medium, there is no risk of mixing another pressure medium (such as hydraulic oil) with the fuel oil. This significantly reduces the need for measures to prevent the mixing of fuel oil and hydraulic oil, thereby greatly simplifying the construction of the need to create a barrier between the two pressure media. In addition, the fuel valve does not require an external control valve for startup, does not require a double-walled hydraulic pipe for the hydraulic medium, does not require a hydraulic control block associated with the hydraulic medium, and the fuel valve itself does not require internal seals, detection between media, and components specifically suitable for hydraulic oil. Therefore, the fuel valve itself and its installation in the engine are significantly simplified. It only requires a cable connection for installation, without a hydraulic control valve, and does not require a double-walled pipe for the hydraulic medium.

[0037] The resilient bias of the fuel valve towards the closed position ensures that the valve member remains shut off to the fuel flow to the main and pilot nozzle orifices when not in use. This prevents fuel leakage and potential safety hazards.

[0038] The valve member is hydraulically urged to the open position by the fuel pressure at the fuel inlet port allowing for smooth and controlled opening of the valve. This ensures a continuous and reliable flow of fuel to the main and pilot nozzle orifices during operation.

[0039] The ability of the valve member to switch on fuel flow to both the main and pilot nozzle orifices and to switch on fuel flow through only the pilot nozzle orifice when in the open position provides flexibility in fuel injection strategy and enables the fuel injection valve to be used for pilot injection only, such as when the main fuel is a different fuel (dual fuel engine), such as natural gas, which is delivered to the combustion chamber through a separate fuel valve specifically designed to deliver the other (main) fuel. This allows the combustion characteristics to be optimized based on the engine operating conditions, thereby improving performance and fuel efficiency.

[0040] In a possible implementation of the first aspect, the first fuel chamber is permanently connected to the fuel inlet port via a line, the line comprising a flow restriction, and wherein the electronically controlled valve connects the first fuel chamber to the fuel control port in the second position.

[0041] The fluid connection of the first fuel chamber to the fuel inlet port and the fluid connection between the first fuel chamber and the fuel control port ensures efficient fuel supply and fuel control. This eliminates the need for additional fuel lines or connections, thereby simplifying the fuel valve design and reducing potential failure points.

[0042] A permanent connection between the first fuel chamber and the fuel inlet port via a conduit including a flow restriction allows the pressure in the first fuel chamber to be changed to the pressure of the fuel control port by opening the conduit that establishes a fluid connection with the fluid control port, because the flow restriction 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 of the fuel supply port in the first fuel chamber.

[0043] The ability of the electronically controlled valve to connect the first fuel chamber to the fuel control port when in the second position provides precise control of the fuel pressure in the first fuel chamber. This allows the operation of the fuel valve to be adjusted for either a pilot injection or a main injection.

[0044] In a possible implementation of the first aspect, the electronically controlled valve connects the first fuel chamber to the fuel inlet port when in the first position, and connects the first fuel chamber to the fuel control port when in the second position.

[0045] The ability of the electronically controlled valve 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 results in the pressure in the fuel supply port causing the blocking member to move to a position where the blocking member limits movement of the valve member to the intermediate position and blocks movement of the valve member to the open position.

[0046] The ability of the electronically controlled valve 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 causes the pressure in the first fuel chamber to correspond to the pressure in the fuel control port. Due to the different selection of the pressure in the fuel control port, preferably the pressure in the fuel control port is low compared to the pressure in the fuel supply port, which causes the blocking member to move to a position that does not block the displacement of the valve member to the open position, thereby allowing the main nozzle opening to open.

[0047] The size 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 lifting to the open position when the fuel pressure in the fuel supply port exists in the first fuel chamber, thereby ensuring the pilot injection.

[0048] In a possible implementation manner of the first aspect, a size of the first surface of the valve member is smaller than a size of the second surface of the blocking member.

[0049] The ability of the fuel valve to selectively block displacement of the valve member from the intermediate position to the closed position provides control over the operating mode of the fuel valve, i.e., control over pilot injection or main injection. This allows the fuel valve to be used as a pilot fuel valve for assisting the ignition of a main fuel delivered by a separate fuel valve dedicated to delivering the main fuel, and also allows the fuel valve to be used as a main fuel valve for liquid fuel. Thus, the present fuel valve is particularly suitable for dual fuel engines, wherein the fuel valve can be used for both injection of liquid fuel and main injection of liquid fuel.

[0050] Movement of the blocking member to the blocking position when the fuel pressure of the fuel supply port is present in the first fuel chamber ensures reliable blocking of the valve member.

[0051] Movement of the blocking member to the non-blocking position allows for unobstructed displacement of the valve member when fuel pressure from the fuel control port is present in the first fuel chamber.

[0052] In a possible implementation of the first aspect, the blocking member includes a plunger, which is received in the hole in a close-fitting manner, the blocking member has a third surface, which is arranged opposite to the second surface, and wherein the valve member has a fourth surface, which is opposite to the first surface and on the opposite side of the third surface.

[0053] The tight fit between the plunger and the bore of the blocking member ensures a safe and secure blocking position, preventing any leakage or accidental movement.

[0054] 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 proper operation of the valve system.

[0055] In the open position and in the intermediate position, the lifting of the displaceable valve member due to the valve seat allows controlled actuation of the flow of liquid fuel.

[0056] In a possible implementation manner of the first aspect, when the blocking member is in the blocking position and the valve member is in the intermediate position, the fourth surface is adjacent to the third surface.

[0057] Attaching the base of the nozzle body to the distal end of the fuel valve provides a secure and stable connection, minimizing the risk of falling out or leaking during operation.

[0058] In a possible implementation of the first aspect, the displaceable valve member rests on a valve seat in the closed position, and the displaceable valve member has a lift due to the valve seat in the open position and in the intermediate position.

[0059] The use of a plunger received in a close-fitting manner in the bore of the blocking member ensures a safe and secure blocking position, thereby preventing any leakage or accidental movement.

[0060] The arrangement of the third surface on the blocking member and the fourth surface on the valve member allows for a precise and stable abutment when the blocking member is in the blocking position and the valve member is in the intermediate position, thereby ensuring proper operation of the fuel valve.

[0061] In a possible embodiment of the first aspect, the nozzle comprises a nozzle body extending along a longitudinal axis from a base at a proximal end of the nozzle body to a closed distal end of the nozzle body, preferably the base is attached to the distal end of the fuel valve.

[0062] Attaching the base of the nozzle body to the distal end of the fuel valve provides a secure and stable connection, minimizing the risk of falling out or leaking during operation.

[0063] In a possible implementation of the first aspect, the nozzle body includes:

[0064] an elongate portion, preferably a barrel portion, extending between a base and a closed distal end,

[0065] an inlet opening to the base for receiving liquid fuel from the fuel valve, and

[0066] A single straight main bore extends longitudinally from the inlet into the nozzle body.

[0067] The tight fit between the plunger and the bore of the blocking member ensures a safe and secure blocking position, preventing any leakage or accidental movement.

[0068] The arrangement of the third surface on the blocking member and the fourth surface on the valve member allows for a precise and stable abutment when the blocking member is in the blocking position and the valve member is in the intermediate position, thereby ensuring proper operation of the valve system.

[0069] In a possible implementation of the first aspect, the displaceable valve member comprises a distal end section having a barrel end section carried by a rod and mounted in a close-fitting manner in the straight main bore, so as to:

[0070] fluidly disconnecting the main nozzle bore from the straight main bore and fluidly disconnecting the pilot nozzle bore from the straight main bore when the displaceable valve member is in the closed position,

[0071] When the displaceable valve member is in the intermediate position, the main nozzle bore is fluidly disconnected from the straight main bore and the pilot nozzle bore is fluidly connected to the straight main bore,

[0072] When the displaceable valve member is in the open position, the main nozzle bore is fluidly connected with the straight main bore and the pilot nozzle bore is fluidly connected with the straight main bore.

[0073] In a possible implementation of the first aspect, the end section of the barrel is hollow to form a fluid channel, preferably, the fluid channel opens to the outside of the shaft at the proximal end, and preferably, the fluid channel opens at the distal end in the axial direction.

[0074] In a possible implementation manner of the first aspect, a cross-sectional area of ​​the pilot nozzle hole is smaller than a cross-sectional area of ​​the main nozzle hole.

[0075] In a possible implementation manner of the first aspect, the main nozzle hole and / or the pilot nozzle hole is a hole.

[0076] In a possible implementation of the first aspect, the main nozzle hole and the pilot nozzle hole are connected to the main hole at axially spaced positions.

[0077] - This configuration allows precise control of fluid flow through the nozzle system since the main and pilot nozzle orifices can be adjusted independently.

[0078] By connecting the main and pilot nozzle holes at axially spaced locations, the degree of lift of the valve member determines whether there is no injection at all, injection only through the pilot nozzle hole, or injection through both the pilot and main nozzle holes.

[0079] In a possible implementation of the first aspect, the displaceable valve member comprises a distal end section having a barrel end section carried by the rod and mounted in a close-fitting manner in the straight main bore.

[0080] - The tight fit between the barrel end section and the main bore ensures a safe and secure connection, preventing any leakage or loss of fluid during operation.

[0081] - This design also allows smooth and precise movement of the displaceable valve member, thereby ensuring accurate control of fluid flow through the nozzle system.

[0082] In a possible implementation of the first aspect, the end section of the barrel is hollow to form a fluid channel, preferably, the fluid channel opens to the outside of the shaft at the proximal end, and preferably, the fluid channel opens at the distal end in the axial direction.

[0083] - The hollow barrel end section provides a dedicated fluid passage that allows efficient and controlled flow of fluid through the nozzle system.

[0084] - With the fluid passage opening proximally to the exterior of the shaft and the fluid passage opening distally in the axial direction, the fluid can be precisely directed to a desired location, thereby enhancing the overall performance and functionality of the nozzle system.

[0085] In a possible implementation manner of the first aspect, a cross-sectional area of ​​the pilot nozzle hole is smaller than a cross-sectional area of ​​the main nozzle hole.

[0086] - This configuration allows precise control of a small fuel flow for pilot injection through the nozzle system, since the cross-sectional area of ​​the pilot nozzle holes is smaller compared to the main nozzle holes, thus restricting the flow.

[0087] - By having different cross-sectional areas for the pilot and main nozzle holes, the fuel flow rate can be selected, providing flexibility and versatility in various applications, particularly in dual fuel engines.

[0088] In a possible implementation manner of the first aspect, the main nozzle hole and / or the pilot nozzle hole is a hole.

[0089] - Using holes for the main nozzle holes and / or the pilot nozzle holes can ensure smooth and consistent flow of fluid through the nozzle system.

[0090] - Hole-based nozzle orifices also provide greater control over flow characteristics, resulting in more accurate and efficient operation of the nozzle system.

[0091] In a possible implementation of the first aspect, the main nozzle hole and the pilot nozzle hole are connected to the main hole at axially spaced positions.

[0092] By connecting the main nozzle bore and the pilot nozzle bore at axially spaced-apart locations, the size of the fuel flow for the pilot injection or the main injection can be selected.

[0093] In a possible implementation of the first aspect, the displaceable valve member comprises a distal end section having a barrel end section carried by the rod and mounted in a close-fitting manner in the straight main bore.

[0094] - The tight fit between the barrel end section and the main bore ensures safe and reliable operation, preventing any leakage or loss of fluid during operation.

[0095] - This design also allows smooth and precise movement of the displaceable valve member, thereby ensuring accurate control of fluid flow through the nozzle system.

[0096] In a possible implementation of the first aspect, the end section of the barrel is hollow to form a fluid channel, preferably, the fluid channel opens to the outside of the shaft at the proximal end, and preferably, the fluid channel opens at the distal end in the axial direction.

[0097] - The hollow barrel end section provides a dedicated fluid passage that allows efficient and controlled flow of fluid through the nozzle system.

[0098] By having the fluid channel open to the outside of the shaft at the proximal end and having the fluid channel open in the axial direction at the distal end, the fluid can be accurately guided to a desired location.

[0099] In a possible implementation form of the first aspect, the valve member is a valve needle, which is slidably received in a longitudinal hole of an elongated valve body, the displaceable valve member rests on a valve seat in a closed position, and the valve needle has a lift caused by the valve seat in an open position and an intermediate position.

[0100] The use of a valve needle as a valve member allows precise control of fuel flow in an engine because the valve needle can be easily adjusted to vary the lift due to the valve seat in the open position and in the intermediate position.

[0101] By arranging the valve seat and / or the fuel chamber in the elongated valve body, the overall size and complexity of the fuel injection system can be reduced, thereby saving manufacturing and maintenance costs.

[0102] Ensuring that all of the primary nozzle holes have substantially equal major cross-sectional areas or diameters, and preferably also substantially equal lengths, promotes even distribution of fuel flow over the nozzle holes, thereby improving engine performance and efficiency.

[0103] In a possible implementation manner of the first aspect, the valve seat and / or the fuel chamber are arranged in the elongated valve body.

[0104] In a possible implementation of the first aspect, all of the main nozzle holes have substantially equal main cross-sectional areas or diameters, and preferably, all of the main nozzle holes also have substantially equal lengths.

[0105] In a possible implementation manner of the first aspect, the main nozzle hole and / or the pilot nozzle hole is open to a surface of the elongated portion. Preferably, the elongated portion is a cylindrical member portion.

[0106] In a possible implementation of the first aspect, the electronically controlled valve is a slide valve. Preferably, the electronically controlled valve is a sliding slide valve. More preferably, the electronically controlled valve is a sliding slide valve type solenoid valve.

[0107] In a possible implementation of the first aspect, the fuel valve comprises a preferably rounded transition surface between the substantially barrel portion of the nozzle body and the flat distal end surface.

[0108] In a possible implementation manner of the first aspect, the straight nozzle holes each have a nozzle axis, wherein the nozzle axis of each of the nozzle holes is arranged to form an obtuse angle α with the main direction X.

[0109] 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 less than 120 degrees. Preferably, the radial component of each nozzle axis relative to the longitudinal axis (X) is roughly evenly distributed on a circular sector with an arc less than 120 degrees.

[0110] According to a second aspect, there is provided a large two-stroke turbocharged uniflow-scavenged internal combustion engine with a crosshead, the large two-stroke turbocharged uniflow-scavenged internal combustion engine comprising a fuel valve according to the first aspect and any possible implementation thereof.

[0111] These and other aspects of the invention will become apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] In the following detailed portion of the present disclosure, the present invention will be explained in more detail with reference to exemplary embodiments shown in the accompanying drawings, in which:

[0113] Figure 1 is an elevation view of a front end end and one lateral side of a large two-stroke unit-flow scavenged turbocharged engine according to an exemplary embodiment;

[0114] Figure 2 yes Figure 1 An elevation view of the rear end portion and another lateral side of the engine;

[0115] Figure 3 is based on Figure 1 A schematic diagram of an engine having an intake system and an exhaust system;

[0116] Figure 4 is used in Figures 1 to 3 A cross-sectional view of an embodiment of a fuel valve used in an engine of prior to a fuel injection event, wherein the valve member is in a closed position;

[0117] Figure 5 yes Figure 4 a cross-sectional view of a fuel valve during fuel injection, wherein the valve member is in an open position and the blocking member is in a non-blocking position;

[0118] Figure 6 yes Figure 4 A more detailed cross-sectional view of the nozzle of the fuel valve in FIG.

[0119] Figure 7 yes Figure 5 A more detailed cross-sectional view of the nozzle of the fuel valve in FIG.

[0120] Figure 8 shows the Figure 4 a fuel valve in which the valve member is in a closed position;

[0121] Fig. 9 yes Figure 4 a cross-sectional view of a fuel valve during fuel injection, wherein the valve member is in an open position and the blocking member is in a blocking position;

[0122] Fig.10 yes Figure 8 A more detailed cross-sectional view of the nozzle of the fuel valve in FIG.

[0123] Fig.11 yes Fig. 9 A more detailed cross-sectional view of the nozzle of the fuel valve in FIG.

[0124] Fig.12 yes Figure 4 An elevation view of the tip of the nozzle of the fuel valve in FIG.

[0125] Fig.13 and Fig.14 yes Fig.12 a transparent view of the tip of the nozzle; and

[0126] Fig.15 Seen from the side of the piston Figure 4 A schematic diagram of the location of a fuel valve nozzle in a cylinder head of an engine and showing the orientation of the nozzle hole and the resulting fuel spray. DETAILED DESCRIPTION

[0127] 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 is shown having a crankshaft 22 and a crosshead 23 . Figure 3A schematic diagram of a large low-speed turbocharged two-stroke internal combustion engine with an intake system and an 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, the engine can be used as a main engine for an ocean-going vessel, or as a stationary engine for operating a generator in a power station. The total output of the engine can be, for example, in the range of 5,000 kW to 110,000 kW.

[0128] The engine may be a two-stroke direct-flow type diesel (compression ignition) engine, which has a scavenging port 19 in the form of an annular piston-controlled port at 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 therefore, the engine is of the so-called direct-flow type. The scavenging air is delivered from the scavenging air receiver 2 to the scavenging air port 19 of each cylinder formed by the cylinder liner 1. The reciprocating piston 21 in the cylinder liner 1 compresses the scavenging air; the fuel is injected via the nozzles of two or three fuel valves 30 arranged in the cylinder head 26. Combustion then occurs, and exhaust gas is produced. When the exhaust valve 4 is opened, the exhaust gas flows through the exhaust duct 20 associated with the relevant cylinder 1 to the exhaust gas receiver 3, and the exhaust gas advances to the turbine 6 of the turbocharger 5 through the first exhaust line 18, and the exhaust gas flows away from the turbine 6 through the second exhaust line 7. The turbine 6 drives a compressor 9 via a shaft 8 , which is supplied via an air inlet 10 .

[0129] The compressor 9 delivers pressurized charge air to a charge air line 11 leading to a charge air receiver 2. The scavenging air in the line 11 passes through an intercooler 12 for cooling the charge air. The cooled charge air is passed via an auxiliary blower 16 driven by an electric motor 17, which, under low or part load conditions, pressurizes the charge air flow to the charge air receiver 2. At higher loads, the turbocharger compressor 9 delivers sufficient compressed scavenging air, and then the auxiliary blower 16 is bypassed via a check valve 15.

[0130] The cylinder is formed in the cylinder liner 1. The cylinder liner 1 is carried by a cylinder frame 25, which is supported by an engine frame 24.

[0131] Fig.15 shows how the nozzle 40 is positioned in the cylinder head 26 peripherally around the discharge valve 4, and Fig.15The direction of fuel injection is shown (which corresponds to the direction of the axes I, II, II, IV and V of the main nozzle holes 45 in the nozzle 40). There are typically at least four main nozzle holes 45 and typically one or two pilot nozzle holes 46. The direction of fuel injection from the pilot nozzle holes 46 is similar to the direction of fuel injection from the main nozzle holes 45. Typically, three (as shown) or four fuel valves 30 are provided per cylinder. In a dual-fuel engine, there will be another 3 or 4 fuel valves (not shown), which are used to inject other fuels; when the other fuel valves are working, the present fuel valve 30 is only used for pilot fuel injection. When other fuels are not used, the present fuel valve 30 is used for main fuel injection. The direction of the vortex of the gas in the combustion chamber is indicated by the curved dashed arrow 96. The cross-sectional area of ​​the pilot nozzle holes 46 is smaller than the cross-sectional area of ​​the main nozzle holes 45, and the number of pilot nozzle holes 46 is typically less than the number of main nozzle holes 45, so the amount of fuel injected through the pilot nozzle holes 46 alone at a given fuel injection pressure is significantly less than the amount of fuel injected through the combined pilot nozzle holes 46 and main nozzle holes 45. Preferably, all of the main nozzle holes in the main nozzle holes 45 have substantially equal major cross-sectional areas or diameters and preferably also substantially equal lengths, and preferably all of the pilot nozzle holes in the pilot nozzle holes 46 have substantially equal pilot cross-sectional areas or diameters and preferably also substantially equal lengths. The major cross-sectional area or diameter of the main nozzle holes 45 is greater than the pilot cross-sectional area or diameter of the pilot nozzle holes 46.

[0132] Figures 4 to 11 An embodiment is shown having two to four fuel valves 30 which are mounted in through holes of the cylinder head 26 of each cylinder, wherein a rear end end 31 of the fuel valve 30 protrudes from an upper side of the cylinder head 26 and wherein a distal end (tip) of the nozzle 40 protrudes slightly into the combustion chamber.

[0133] Figure 12 to Figure 14 The distal end of the nozzle 40 is shown in greater detail.

[0134] The fuel valve 30 comprises an elongated fuel valve body 32 having a nozzle 40 at a distal end (front end) 33. Liquid fuel (e.g. ethanol, methanol, diesel, heavy fuel oil) is delivered to the combustion chamber 14 via the nozzle 40 by the fuel valve 30 in a controlled and timed manner. The fuel valve 30 has an elongated body 32 having a head at its proximal end 31, by which the fuel valve 30 can be mounted in a known manner in the cylinder head 26 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 reduces the pressure. A typical maximum fuel injection pressure is above 200 bar, preferably, the maximum fuel injection pressure is above 300 bar.

[0135] The head at the proximal end 31 comprises a fuel inlet port 83 which is fluidly connected to the conduit 62 extending through the valve body 32. An axially displaceable valve member 35, preferably a valve needle, is journaled in the valve housing 32 and has an open position in which the valve member 35 has a lift due to a preferably conical 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 a mating section of the valve member 35 rests on the valve seat 36 in a sealing manner. The valve needle is resiliently biased towards the closed position by resilient means, which in the present embodiment is formed by a coil spring 87. The lift of the valve needle 35 against the bias of the coil spring 87 is caused by the pressure of the fuel supplied to the fuel supply port 83 acting on the first surface of the valve member 35. In the present embodiment, the pressure in the second fuel chamber 68 acts on the first surface of the valve member 35 to move the valve member 35 toward the open position.

[0136] The fuel valve 30 carries a nozzle 40 at its distal end 33. The nozzle 40 is arranged to protrude into the combustion chamber 14 of the engine cylinder liner 1 through five nozzle holes 46 or through both a pilot nozzle hole 46 and a main nozzle hole 45.

[0137] In the present embodiment, the fuel valve 30 comprises an axially movable valve member 35 in the form of a needle, which comprises a tapered section cooperating with a tapered seat 36 in the longitudinal body 32 of the fuel valve 30, the valve seat 36 opening into a second fuel chamber 68 surrounding an axial portion of the valve member 35 and accommodating a coil spring 87. The fuel conduit 62 connects the fuel inlet port 83 to the second fuel chamber 68.

[0138] A fuel control port 85, which opens to a surface of the body of the fuel valve 30 (preferably near its rearmost or proximal end), receives a reference fuel pressure or a control fuel pressure (by connecting to a substantially constant fuel pressure source). In the present 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, the two positions are an open position or a 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 slide valve, preferably, the electronically controlled valve 60 is a sliding slide valve, and more preferably, the electronically controlled valve 60 is a sliding slide valve type solenoid valve.

[0139] The first fuel chamber 81 is connected to the fuel inlet port 83 by a conduit 67 including a restriction device 64 (e.g., in the form of an orifice or other suitable device) to ensure that when the electronically controlled valve 60 is in the open position, 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. A displaceable blocking member 80 in the form of a plunger is received in a hole in the valve body 32 in a close-fitting manner to allow the displaceable blocking member 80 to be axially displaced between a blocking position and a non-blocking position. The first fuel chamber 81 is formed in the hole in the valve body, and the blocking member has a second (axially facing) surface that is exposed to the fuel pressure in the first fuel chamber 81. Opposite to the second surface, the blocking member has a reduced diameter section that is received in a matching hole 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 that is arranged opposite to the second surface. The most proximal end section of the valve member 35 is provided with a fourth surface, 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, so when the first surface and the third surface are both 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 abuts the third surface, as shown in FIG. Fig. 9 As shown, the valve member 35 is thereby blocked from moving from the intermediate position to the open position.

[0140] The electronically controlled valve 60 is configured such that: when the electronically controlled valve 60 is in the closed position, the electronically controlled valve 60 allows the fuel pressure of the fuel supply port 83 to exist in the first fuel chamber 81, and when the electronically controlled valve 60 is in the open position, the electronically controlled valve 60 allows the fuel pressure of 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 displacement of the valve member 35 from the intermediate position to the open position, and in the non-blocking position, the blocking member 80 does not block the displacement of the valve member 35 from the intermediate position to the open position. When the fuel pressure of the fuel supply port 83 exists in the first fuel chamber 81, that is, when the electronically controlled valve 60 is in the open position, the blocking member 80 moves to Fig. 9 The blocking position shown in the figure, and when the fuel pressure of the fuel control port 85 is present in the first fuel chamber 81, that is, 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.

[0141] Figure 12 to Figure 14 The distal end section of the valve needle 35 and the nozzle 40 are shown in more detail.

[0142] The nozzle 40 has a nozzle body extending along a longitudinal axis (X) from a base 42 at a proximal end 41 to a closed distal end 44 forming the tip of the nozzle 40. A barrel portion 43 of the nozzle body extends from the base to the distal end 44. The nozzle body is made of a suitable material, such as a suitable alloy as is known in the art.

[0143] When the valve needle 35 is in the intermediate or open position, the inlet 48 opens to the base 42 for receiving liquid fuel from the fuel valve 30. A straight main bore 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 is connected to the barrel portion via a curved or rounded transition surface 49.

[0144] 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 .

[0145] When the fuel valve 30 is in the open position, each main nozzle hole 45 opens to the outer surface of the nozzle body 43 at a different radial angle so that the fuel ray fan (eg Fig.14 43 and 49). The pilot nozzle hole 46 is opened to the outer surface of the nozzle body at a different radial angle. Preferably, the main nozzle hole 45 is opened to the barrel surface 43 and / or the transition surface 49. Similarly, the pilot nozzle hole 46 is opened to the barrel surface 43 and / or the transition surface 49 at an appropriate radial angle.

[0146] The base 42 is provided with an inlet port 48 for receiving fuel from the fuel valve body 32. The main bore 50 extends from the inlet port 48 into the nozzle body and extends in the direction of the main axis X into the barrel portion 43 to a position close to 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 is connected to the main nozzle bore 45 at a first axial distance from the distal end 44, and is connected to the pilot nozzle bore 46 at a second axial distance from the distal end 44. The second axial distance is smaller than the first axial distance, so that the flow from the main bore 50 to the pilot nozzle bore 46 can be achieved with a small lift / small axial displacement of the valve member 35 in the direction of the open position, while the flow from the main bore 50 to the main nozzle bore 46 is only allowed when the valve member 35 has a large lift or a large axial displacement in the direction toward the open position. Fig.14 Compared to the shorter double arrow in Fig.13 The longer double arrow in FIG. 3 shows the difference in lift of the valve member 35 and its barrel portion 39, wherein Fig.13 The valve member 35 is shown in an open position, and Fig.14 The valve member 35 is shown in an intermediate position.

[0147] The valve needle 35 includes a distal end section including a barrel end section 39 carried by a shank 38. The barrel end section 39 is hollow to form a fluid passage 71 for fuel from the proximal side of the barrel end section 39 to the distal side of the barrel end section 39. The fluid passage 71 opens at the proximal end to the outside of the shank 38, and the fluid passage 71 opens at the distal end in the axial direction.

[0148] The cartridge end section 39 is mounted in a close-fitting manner in the straight main bore 50 to fluidically disconnect the pilot nozzle bore 46 from the straight main bore 50 and to fluidly disconnect the main nozzle bore 45 from the straight main bore 50 when the valve needle 35 is in the closed position, as shown in FIG. Figure 4 , Figure 6 and Fig.10As shown, when the valve needle 35 is in the closed position, the barrel end section 39 covers the openings of the pilot nozzle hole 46 and the main nozzle hole 45 to the main hole 50. Therefore, when the valve member 35 is in the closed position, any fuel in the space between the valve seat 36 and the distal end of the main hole 50 can be prevented from leaking into the combustion chamber 14.

[0149] In the intermediate position of the valve member 35, lifting / axial movement toward the open position of the valve member causes the barrel portion 39 to cover only the opening of the main nozzle hole 45 to the main bore, thereby allowing fuel to be injected into the combustion chamber via the pilot nozzle hole 46, but not through the main nozzle hole 45 into the combustion chamber, as shown in FIG. Fig. 9 and Fig.11 shown.

[0150] When the valve member 35 is in the open position, the barrel end section 39 fluidly connects the opening of the pilot nozzle bore 46 to the straight main bore 50 and the opening of the main nozzle bore 45 to the straight main bore 50, as shown in FIG. Figure 5 and Figure 7 As shown, by leaving the barrel end section 39 uncovered from the opening of any of the nozzle bores 45, 46 toward the straight main bore 50, fuel is allowed to be injected into the combustion chamber through both the pilot nozzle bore 46 and the main nozzle bore 45 for a main fuel injection event.

[0151] In an embodiment of the fuel valve 30 (not shown), the electronically controlled valve 60 connects the first fuel chamber 81 to the fuel inlet port 83 when in the first position, and the electronically controlled valve 60 connects the first fuel chamber 81 to the fuel control port 85 when in the second position, and there is no need to restrict the fluid connection between the fuel inlet port and the first pressure chamber.

[0152] The invention has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments may be understood and effected by those skilled in the art in practicing the claimed invention 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 article "a" or "an" does not exclude a plurality. Merely because certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be fully utilized. The reference signs used in the claims should not be construed as limiting the scope.

Claims

1. A fuel valve (30) for injecting liquid fuel into a combustion chamber of a large two-stroke turbocharged uniflow scavenged internal combustion engine having a crosshead, the fuel valve (30) comprising: - a fuel inlet port (83), - fuel control port (85), - one or more main nozzle holes (45), - one or more pilot nozzle holes (46), a valve member (35) which is displaceable between a closed position and an open position and which has an intermediate position between the closed position and the open position, wherein the valve member (35) is resiliently biased toward the closed position and hydraulically urged toward the open position by the fuel pressure of the fuel inlet port (83) acting on the first surface of the valve member (35), wherein the valve member (35) shuts off the fuel flow to one or more of the main nozzle holes (45) and shuts off the fuel flow to one or more of the pilot nozzle holes (46) in the closed position, wherein the valve member (35) shuts off the fuel flow to one or more of the main nozzle holes (45) and connects the fuel flow to one or more of the pilot nozzle holes (46) when in the intermediate position, wherein the valve member (35) enables fuel flow to one or more of the main nozzle holes (45) and enables fuel flow to one or more of the pilot nozzle holes (46) in the open position, Features - means for selectively blocking displacement of the valve member (35) from the intermediate position to the open position, Wherein, the device comprises: a blocking member (80) having a second surface which is exposed to the fuel pressure in the first fuel chamber (81), - an electronically controlled valve (60), preferably, the electronically controlled valve (60) is a solenoid valve, the electronically controlled valve (60) has at least a first position and a second position, and the electronically controlled valve (60) is configured to: - in the first position, the electronically controlled valve (60) causes the fuel pressure of the fuel supply port (83) to be present in the first fuel chamber (81), and - in the second position, the electronically controlled valve (60) causes the fuel pressure at the fuel control port (85) to be present 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 displacement 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 displacement of the valve member (35) from the intermediate position to the open position. Wherein, the blocking member (80) is configured as follows: - moving the blocking member (80) to the blocking position when the fuel pressure of the fuel supply port (83) is present in the first fuel chamber (81), and - moving the blocking member (80) to the non-blocking position when fuel pressure from the fuel control port (85) is present in the first fuel chamber (81).

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 line (67), the line (67) including a flow restriction (64), and wherein the electronically controlled valve (60) connects the first fuel chamber (81) to the fuel control port (85) when in the second position.

4. The fuel valve (30) according to any one of claims 1 to 3, wherein: The electronically controlled valve (60) connects the first fuel chamber (81) to the fuel inlet port (83) when in the first position, and connects the first fuel chamber (81) to the fuel control port (85) when in the second position.

5. The fuel valve (30) according to any one of the preceding claims, wherein: The first surface of the valve member (35) has a size smaller than the second surface of the blocking member (80).

6. A fuel valve (30) according to any one of the preceding claims, wherein: The blocking member (80) includes a plunger received in the hole in a close-fitting manner, the blocking member (80) having 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 on the opposite side to the third surface.

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

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

9. A fuel valve (30) according to any one of claims 1 to 5, comprising 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 valve body (32).

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

11. The fuel valve (30) according to claim 10, wherein: The nozzle body comprises: an elongated portion, preferably a barrel portion (43), extending between the base (42) and the closed distal end (44), an inlet (48) opening into the base (42), the base (42) being adapted to receive liquid fuel from the fuel valve (30), and A single straight main bore (50) extends longitudinally from the inlet (48) into the nozzle body.

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

13. The fuel valve (30) according to claim 11 or 12, wherein: The displaceable valve member (35) comprises a distal end section having a barrel end section (39) carried by a rod (38) and mounted in a close-fitting manner in the straight main bore (50) to: When the displaceable valve member (35) is in the closed position, the main nozzle bore (45) is fluidly disconnected from the straight main bore (50) and the main nozzle bore (45) is fluidly disconnected from the pilot nozzle bore (46), When the displaceable valve member (35) is in the intermediate position, the main nozzle hole (45) is fluidly disconnected from the straight main hole (50) and the pilot nozzle hole (46) is fluidly connected to the straight main hole (50), When the displaceable valve member (35) is in the open position, the main nozzle bore (45) is fluidly connected with the straight main bore (50) and the pilot nozzle bore (46) is fluidly connected with the straight main bore (50).

14. The fuel valve (30) according to claim 13, wherein: The barrel end section (39) is hollow to form a fluid passage (71), preferably, the fluid passage (71) opens proximally to the exterior of the shaft (38), and preferably, the fluid passage (71) opens distally in an axial manner.

15. A fuel valve (30) according to any one of the preceding claims, in, The cross-sectional area of ​​the pilot nozzle hole (46) is smaller than the cross-sectional area of ​​the main nozzle hole (45).

16. A fuel valve (30) according to any one of the preceding claims, wherein: The main nozzle hole (45) and / or the pilot nozzle hole (46) are holes.

17. The fuel valve (30) according to any one of claims 1 to 16, wherein: The valve member (35) is a valve needle, which is slidably received in a longitudinal hole (64) in the elongated valve body (32), the valve member (35) rests on a valve seat (36) in the closed position, and the valve needle (35) has a lift caused by the valve seat (36) in the open position and the intermediate position.

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

19. The fuel valve (30) according to claim 17 or 18, wherein: The valve seat (36) and / or the second fuel chamber (68) are arranged in the elongated valve body (32).

20. The fuel valve (30) according to any one of claims 1 to 19, wherein: All of the primary nozzle holes (45) have substantially equal major cross-sectional areas or diameters, and preferably all of the primary nozzle holes (45) also have substantially equal lengths.

21. The fuel valve (30) according to any one of claims 1 to 20, wherein: All of the pilot nozzle holes (46) have substantially equal pilot cross-sectional areas or diameters, and preferably all of the pilot nozzle holes (46) also have substantially equal lengths.

22. The fuel valve (30) according to claim 20 or 21, wherein: The major cross-sectional area or diameter is greater than the pilot cross-sectional area or diameter.

23. The fuel valve (30) according to any one of claims 11 to 22, wherein: The main nozzle hole (45) and / or the pilot nozzle hole (46) are open to the surface of the elongated portion, preferably, the elongated portion is a barrel portion.

24. The fuel valve (30) according to any one of claims 1 to 23, wherein: The electronically controlled valve (60) is a slide valve. Preferably, the electronically controlled valve (60) is a sliding slide valve. More preferably, the electronically controlled valve (60) is a sliding slide valve type solenoid valve.

25. A large two-stroke turbocharged uniflow-scavenged internal combustion engine with a crosshead, comprising a fuel valve (30) according to any one of claims 1 to 24.

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