Fuel valve and engine including the same

Abstract

A fuel valve (30) for injecting fuel into a large two-stroke turbocharged straight-flow scavenging internal combustion engine has an axially displaceable valve needle (35) cooperating with a valve seat (36) in a valve body, a cylindrical distal end section (39) of the valve needle (35) being located in a nozzle (40), the cylindrical distal end section (39) being provided with a sealing ring (52).

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. Background Technology

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

[0003] These engines' cylinders are equipped with: a single exhaust valve centrally located within the cylinder head cover, i.e., at the top of the cylinder; and a ring of piston-controlled scavenging ports in the lower region of the cylinder liner. Therefore, the gas is always transported through the cylinder from bottom to top, hence the term direct-flow scavenging. The scavenging ports are angled to create vortices in the gas within the combustion chamber.

[0004] In the cylinder head cover, two or three fuel valves are arranged around a centrally located exhaust valve, with nozzles for these valves extending into the combustion chamber. The fuel valves are circumferentially (i.e., not centrally) positioned within the cylinder head cover, and the nozzle orifices generally point towards the swirl, away from the cylinder wall and towards the combustion chamber. Occasionally, a single nozzle orifice points in the opposite direction to the swirl within 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 that protrudes from the upper surface of the cylinder cover at the proximal or rear end, and the elongated fuel valve housing extends through the cylinder cover, with a nozzle at the front or rear end of the elongated fuel valve housing extending into the combustion chamber.

[0006] Known nozzles for large, crosshead-type two-stroke diesel engines typically have an elongated nozzle body comprising a cylindrical section with straight main orifices extending from the base of the nozzle at the proximal end of the nozzle body to nozzle openings located near the distal end of the nozzle body. Since the nozzle openings cannot point downwards towards 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 distal end of the nozzle), the distal end can be rounded or flat, but is closed. Therefore, the nozzle openings are primarily laterally oriented relative to the main axis of the nozzle / fuel valve and are typically almost perpendicular to the main axis of the engine cylinder. Typically, each nozzle has three to seven nozzle openings, all of which connect to the main orifice.

[0007] Typically, known fuel valves for injecting liquid fuel are equipped with an axially displaceable valve needle that cooperates with a conical valve seat to control the flow rate of fuel toward the nozzle. Furthermore, the front section of the valve needle includes a distal cylindrical section that is tightly received within the main orifice, and this distal cylindrical section acts as a sliding valve to close the nozzle orifice when the valve needle is in the closed position, thereby significantly reducing the so-called sac volume, i.e., the volume of fuel remaining in the space within the nozzle formed by the main orifice. Without this sliding valve device, the residual volume of fuel in the main orifice (and nozzle orifice) would drip into the combustion chamber after the fuel injection event, which would adversely affect fuel consumption, reliability, and emissions.

[0008] Because the nozzle body extends into the combustion chamber, it is exposed to the hot gases in the combustion chamber, and therefore, certain parts of the nozzle body will reach a relatively high temperature of about 400°C.

[0009] DK181704B1 discloses a fuel valve for injecting fuel into a large two-stroke turbocharged direct-flow scavenging internal combustion engine. The fuel valve includes: a fuel valve housing having an axis, a proximal end, and a distal end; an axially displaceable valve needle having a closed position and an open position, wherein in the closed position the valve needle rests on a valve seat and in the open position the valve needle is lifted from the valve seat; and an atomizing nozzle disposed at the distal end of the elongated valve housing. The atomizing nozzle has a nozzle body extending along the axis from a base at a proximal end of the nozzle body to a closed distal end of the nozzle body, and the atomizing nozzle includes: a generally cylindrical portion extending between the base and the closed distal end; an inlet opening leading to the base for receiving liquid fuel from the fuel valve; a plurality of straight nozzle openings, each opening opening opening to an outer surface of the nozzle body at a different radial angle; a single straight main opening extending longitudinally from the inlet to the nozzle body, the straight nozzle openings being connected to the straight main opening via respective supply channels, each supply channel being angled to the straight main opening and the associated straight nozzle opening; and a valve needle including a distal section with a cylindrical end section carried by a shank, the distal section being journal-connected in a close-fitting manner within the straight main opening when the valve needle is in the closed position, so as to disconnect the respective supply channels from the straight main opening.

[0010] This known design works well with conventional fuels such as fuel oil. However, to reduce or even avoid carbon dioxide emissions, different types of fuel components, such as ammonia, have been used. Tests have shown that this conventional design is not suitable for ammonia or other low-viscosity fuels for the following reasons: When the fuel valve is closed and ammonia is not supported to enter the combustion chamber, the low viscosity of ammonia, coupled with the rapid heating and boiling of the ammonia stagnating above the distal column section due to heat conduction from the combustion chamber to the nozzle, creates pressure that forces the ammonia through the distal column section and into the combustion chamber. Therefore, when operating with ammonia, the barrier created by the distal column section, tightly contained within the main opening, is insufficient. This, in turn, results in underburned or unburned ammonia entering the emission system, a highly undesirable situation. Summary of the Invention

[0011] In view of the above, the objective 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 above-mentioned problems.

[0012] The above and other objectives are achieved by the features in the independent claims. Further implementations are readily apparent from the dependent claims, the specification, and the drawings.

[0013] According to a first aspect, a fuel valve is provided for injecting liquid fuel into a large, two-stroke, turbocharged, direct-flow scavenging internal combustion engine having a crosshead, the fuel valve comprising: The elongated fuel valve housing has a longitudinal axis, a proximal end, and a distal end. An axially displaceable valve needle has a closed position and an open position. In the closed position, the valve needle rests on the valve seat; in the open position, the valve needle is lifted off the valve seat. The atomizing nozzle is located at the far end of the elongated valve body. The atomizing nozzle has a nozzle body that extends along a longitudinal axis from a base at a proximal end to a closed distal end of the nozzle body, the base being attached to the distal end of the fuel valve housing. The nozzle body includes: The elongated portion, preferably a cylindrical elongated portion, extends between the base and the closed distal end. The inlet, which leads to the base, is used to receive liquid fuel from the fuel valve. Multiple nozzle openings, The main opening extends longitudinally from the inlet into the nozzle body. The valve needle includes a cylindrical distal section carried by the shank. When the valve needle is in the closed position, the distal section of the cylindrical part is journaled in a tight fit with the distal portion of the main orifice, thereby disconnecting the nozzle orifice from the fluid in the main orifice. The distal section of the cylindrical section is provided with a circumferential groove, within which a sealing ring is maintained. In the closed position of the valve needle, the main opening has a continuous cylindrical surface facing the sealing ring, and In the open position of the valve needle, the main opening has a discontinuous cylindrical surface facing the sealing ring, and the discontinuity in the discontinuous cylindrical surface is formed by a plurality of circumferentially spaced axial grooves.

[0014] By providing a sealing ring and an intermittent surface that accommodates the sealing ring in a circumferential groove when the valve needle is in the open position while allowing fuel to pass through the groove, the fuel valve can be equipped with a sealing ring in the distal cylindrical section capable of sealing low-viscosity fuels, thereby preventing fuel leakage into the combustion chamber when the fuel valve is closed. This, in turn, reduces unintended emissions.

[0015] According to a possible implementation of the first aspect, the main opening has a larger first diameter near the end of the axial groove, and a smaller second diameter in the region of the axial groove and at the location where the main opening forms a continuous cylindrical surface facing the sealing ring in the closed position of the valve needle.

[0016] According to a possible implementation of the first aspect, the handle has a smaller cross-sectional area than the distal section of the column.

[0017] According to a possible implementation of the first aspect, when the valve needle is in the closed position, the cylindrical distal section disconnects the opening of the nozzle orifice from the portion of the main orifice near the cylindrical distal section.

[0018] According to a possible implementation of the first aspect, when the valve needle is in the open position, the cylindrical distal section connects the opening of the nozzle orifice with the portion of the main orifice near the cylindrical distal section.

[0019] According to a possible implementation of the first aspect, an axially displaceable valve needle is slidably received in a longitudinal opening in an elongated valve housing, the valve needle resting on a valve seat in the closed position, preferably resting on a tapered valve seat in the closed position, the valve needle being lifted from the valve seat in the open position, and preferably, the valve needle being biased toward the closed position in an elastic and / or fluid manner, and preferably, a fuel chamber surrounding the valve needle and leading to the valve seat.

[0020] According to a possible implementation of the first aspect, the fuel valve includes a fuel inlet port in an elongated fuel valve housing for connection to a liquid fuel source.

[0021] According to the possible implementation of the first aspect, the nozzle orifice points in a generally radial direction.

[0022] According to a possible implementation of the first aspect, each nozzle orifice has a nozzle axis, and the nozzle axis of each nozzle orifice in the nozzle orifice is set at an obtuse angle α with the longitudinal axis X.

[0023] According to a possible implementation of the first aspect, the radial components of each nozzle axis relative to the longitudinal axis are distributed on a circular sector with an arc of less than 120 degrees. Preferably, the radial components of each nozzle axis relative to the longitudinal axis are distributed approximately evenly on a circular sector with an arc of less than 120 degrees. More preferably, the radial components of each nozzle axis relative to the longitudinal axis are distributed on a circular sector with an arc of less than 110 degrees. More preferably, the radial components of each nozzle axis relative to the longitudinal axis are distributed approximately evenly on a circular sector with an arc of less than 110 degrees. Even more preferably, the radial components of each nozzle axis relative to the longitudinal axis are distributed on a circular sector with an arc of less than 100 degrees. Even more preferably, the radial components of each nozzle axis relative to the longitudinal axis are distributed approximately evenly on a circular sector with an arc of less than 100 degrees.

[0024] According to the possible implementation of the first aspect, the fuel valve includes three to twelve axial grooves.

[0025] According to the possible implementation of the first aspect, the circumferential groove retains two or more sealing rings.

[0026] According to a possible implementation of the first aspect, the sealing ring includes a ring-shaped partition portion, preferably, the sealing ring includes a leak-proof ring-shaped partition portion.

[0027] According to a second aspect, a large two-stroke turbocharged direct-flow scavenging internal combustion engine with a crosshead is provided, including a fuel valve according to the first aspect and any implementation thereof.

[0028] These and other aspects will become apparent from the examples and implementations described below. Attached Figure Description

[0029] In the following detailed sections of this disclosure, the invention will be described in more detail with reference to the exemplary embodiments shown in the figures, wherein: Figure 1 This is a top view showing the front end and one side of a large two-stroke unit-sweeped turbocharged engine according to an exemplary embodiment. Figure 2 It shows Figure 1A top view of the rear end and the other side of the engine. Figure 3 It is based on Figure 1 A schematic diagram of the engine and its intake and exhaust systems. Figure 4 Is Figures 1 to 3 A side view of an embodiment of the fuel valve used in an engine. Figure 5 yes Figure 4 A cross-sectional view of the fuel valve. Figure 6 yes Figure 4 and Figure 5 A cross-sectional view of the nozzle of the fuel valve. Figure 7 yes Figure 6 A top view of the nozzle. Figure 8 yes Figure 4 and Figure 5 fuel valve and Figure 6 and Figure 7 Cross-sectional views of different front sections of the nozzle. Figure 9 It runs through Figure 8 The cross-sectional view of the nozzle shown illustrates the circumferentially distributed longitudinal recesses. Figure 10 It runs through Figure 8 Another cross-sectional view of the nozzle shown illustrates the sealing ring. Figure 11 yes Figure 8 Another cross-sectional view of the front section of the fuel valve. Figure 12 yes Figure 8 Another cross-sectional view of the front section of the fuel valve. Figure 13 yes Figure 8 Detailed cross-sectional view of the nozzle of the fuel valve. Figure 14 This is a top view of the distal section of the valve needle with the sealing ring. Figure 15 This is a top view of the sealing ring, and Figure 16 This was observed from the piston side. Figure 5 A schematic diagram showing the position of the fuel valve nozzle in the cylinder cover, and illustrating the nozzle opening and the orientation of the resulting fuel jet. Detailed Implementation

[0030] 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 3A large, low-speed turbocharged two-stroke internal combustion engine with crankshaft 22 and crosshead 23 is shown. Figure 3 A schematic diagram of a large, low-speed turbocharged two-stroke internal combustion engine and its intake and exhaust systems is shown. In this exemplary embodiment, the engine has six inline cylinders (formed by cylinder liners 1). Large turbocharged two-stroke internal combustion engines typically have between five and sixteen inline cylinders, supported by an engine frame 24. The engine can be used, for example, as a main engine in ocean-going vessels or as a stationary engine operating generators in power plants. For example, the total output power of the engine can be in the range of 5,000 kW to 110,000 kW.

[0031] The engine can be a two-stroke direct-flow diesel (compression ignition) engine, which has: a scavenging port 19, which is in the form of a piston-controlled port in the lower region of the cylinder liner 1; and an exhaust valve 4 located at the top of the cylinder liner 1. Therefore, the flow in the combustion chamber is always from bottom to top, hence the engine is a so-called direct-flow engine. 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, and fuel is injected via nozzles of two or three fuel valves 30 located in the cylinder cover 26. Combustion then occurs, producing exhaust gases. When the exhaust valve 4 is open, the exhaust gases flow through the exhaust pipe 20 connected to the exhaust gas receiver 3 associated with the cylinder 1, and forward through the first exhaust line 18 to the turbine 6 of the turbocharger 5, from which the exhaust gases exit through the second exhaust line 7. Turbine 6 drives compressor 9 via shaft 8, and compressor 9 is supplied with air by air inlet 10.

[0032] Compressor 9 delivers pressurized filling air to filling air line 11, which leads to filling air receiver 2. The scavenging air in line 11 passes through intercooler 12 to cool the filling air. The cooled filling air is then delivered to filling air receiver 2 via auxiliary blower 16 driven by electric motor 17, which pressurizes the filling air flow under low or partial load conditions. Under higher load conditions, turbocharger compressor 9 delivers fully compressed scavenging air, and then auxiliary blower 16 is bypassed via check valve 15.

[0033] The cylinder is formed by a cylinder liner 1. The cylinder liner 1 is supported by a cylinder frame 25, which is supported by an engine frame 24.

[0034] Figures 4 to 15An embodiment of one of two or three fuel valves 30 is shown, which is mounted in a through-hole in the cylinder cover 26 of each cylinder. The rear end 32 of the fuel valve 30 protrudes from the upper side of the cylinder cover 26, and the distal end (slight end) of the nozzle 40 protrudes slightly into the combustion chamber. The fuel valve 30 includes an elongated fuel valve body 32, which has a nozzle retainer at its distal end (front end) 33. The nozzle retainer connects the nozzle 40 to the elongated fuel valve body 32. Liquid fuel (e.g., ammonia, ethanol, methanol, diesel, heavy fuel oil) is delivered to the combustion chamber 14 in a controlled and timed manner through the fuel valve 30 and the nozzle 40. Figure 4 The fuel valve 30 shown has an elongated outer housing 32 with a head at its proximal end 31. The fuel valve 30 can be mounted in the cylinder cover 26 in a known manner through this head and connected to the fuel pump (not shown) of the internal combustion engine.

[0035] The head at the proximal end 31 includes a fuel inlet, which is in fluid communication with a conduit extending through the valve body 32. An axially displaceable valve needle 35 is journal-connected to the valve housing 32 and has an open position and a closed position. In the open position, the valve needle 35 is raised from a preferably tapered valve seat 36; in the closed position, the mating section of the valve needle 35 rests sealingly on the valve seat 36. The valve needle 35 is elastically biased toward the closed position by an elastic device, in this embodiment, formed by a helical spring 83. The lifting of the valve needle 35 against the bias of the helical spring 83 is caused by the pressure of fuel supplied to the fuel valve 30, which acts on the surface of the valve needle 35 or on the surface of a piston or plunger operably connected to the valve needle 35. The fuel valve 30 carries a nozzle 40 at its distal end 33. The nozzle 40 is configured such that when the fuel valve 30 is mounted on the cylinder cover 26, the nozzle 40 extends into the combustion chamber 14 of the engine cylinder liner 1.

[0036] In this embodiment, the fuel valve 30 includes an axially movable valve needle 35, which includes a tapered section that cooperates with a tapered seat 36 in the longitudinal housing 32 of the fuel valve 30. Figure 16 The diagram illustrates how the nozzle 40 is circumferentially positioned within the cylinder cover 26, and shows the direction of the fuel jet (corresponding to the directions of axes I, II, III, IV, and V of the nozzle orifice 45 in the nozzle 40). The direction of the gas vortex in the combustion chamber is indicated by curved, discontinuous arrows 66.

[0037] The fuel valve 30 includes an optional booster pump to amplify the pressure of the fuel supplied to the fuel valve 30. The main component of the booster pump is the booster plunger 80.

[0038] Figures 6 to 11 The distal sections of nozzle 40 and valve needle 35 are shown in more detail. The nozzle 40 has a nozzle body that extends from a base 42 at a proximal end to a closed distal end 44, which forms the distal end 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 as is well known in the art, such as a suitable alloy (e.g., tool steel).

[0039] Inlet 48 leads to base 42 for receiving liquid fuel from fuel valve 30 when valve needle 35 is in the open position. Main opening 50 extends longitudinally from inlet 48 into nozzle body. The closed distal end (slight end portion) 44 includes a substantially flat end surface 47 having a circular or elliptical profile. The end surface 47 connects to the cylindrical portion via a curved or circular transition surface.

[0040] The nozzle 40 is provided with a plurality of (preferably straight) openings 45. The nozzle 40 is provided with any desired number of nozzle openings 45, preferably between three and seven, even more preferably between three and six, and most preferably five or six nozzle openings 45. The nozzle 40 according to this embodiment is provided with six nozzle openings 45.

[0041] Each nozzle orifice 45 extends towards the outer surface of the nozzle body 43 at a different radial angle to deliver a fan-shaped fuel jet (e.g., when the fuel valve 30 is open). Figure 16 (As shown) is injected into the combustion chamber. Each nozzle orifice 45 opens to the outer surface of the nozzle body at a different radial angle. Preferably, the nozzle orifice 45 opens to the cylindrical surface 43 and / or the transition surface. Each of the nozzle orifices 45 has nozzle axes I, II, III, IV and V ( Figure 16The nozzle axes I, II, III, IV, and V of each of the nozzles in orifice 45 are set at an obtuse angle α with respect to the main axis X. The obtuse angle α can be different for each nozzle orifice 45. The radial components of each nozzle axis I, II, III, IV, and V relative to the main axis X are distributed on a circular sector with an arc of less than 120 degrees. Preferably, the radial components of each nozzle axis I, II, III, IV, and V relative to the main axis X are distributed on a circular sector with an arc of less than 110 degrees. Even more preferably, the radial components of each nozzle axis I, II, III, IV, and V relative to the main axis X are distributed on a circular sector with an arc of less than 100 degrees. The radial components of each nozzle axis (I, II, III, IV, and V) relative to the main axis X are distributed substantially uniformly on a circular cross-section to maximize the amount of nozzle body material between the individual nozzle orifices 45.

[0042] The base 42 is provided with an inlet port 48 for receiving fuel from the fuel valve 30. A main opening 50 extends from the inlet port 48 into the nozzle body and the cylindrical portion 43 along the main axis X, and extends to a position near the distal end 44 of the nozzle body. The main opening 50 connects to a plurality of nozzle openings 45.

[0043] In this embodiment, the inlet port 48 is formed by an opening with a diameter larger than that of the main opening 50. Alternatively, the inlet port 48 may have the same diameter as the main opening.

[0044] The valve needle 35 includes a distal section comprising a cylindrical distal section 39 carried by a shank 38, preferably having a diameter / cross-sectional area smaller than that of the cylindrical distal section 39.

[0045] When the valve needle 35 is in the closed position, the cylindrical distal section 39 is journal-connected to the distal portion of the main opening 50 in a tight fit, thereby fluidly disconnecting the nozzle opening 45 from the main opening 50.

[0046] The distal cylindrical section 39 is provided with a circumferential groove 54 in which a sealing ring 52 is held. The sealing ring 52 is made of a suitable alloy suitable for high temperature and high pressure and has a ring-shaped partition 53. The piston ring may be coated with a diamond-like carbon (DLC) coating. In the closed position of the valve needle 35, the main opening 50 has a continuous cylindrical surface facing the sealing ring 52. The sealing ring 52 abuts against this continuous cylindrical surface to seal and prevent fuel (also a low-viscosity fuel) from leaking through the distal cylindrical section 39.

[0047] In the open position of the valve needle 35, the opening 50 has a discontinuous cylindrical surface facing the sealing ring 52. The discontinuities in the discontinuous cylindrical surface are formed by a plurality of circumferentially spaced axial grooves 63. In this embodiment, there are six axial grooves, but there may be as few as three or as many as twelve. The discontinuous cylindrical surface keeps the sealing ring 52 compressed within the circumferential grooves 54 while allowing fuel to flow through the axial grooves 63. Keeping the sealing ring 52 compressed is advantageous; otherwise, the sealing ring 52 or the moving surface on which it acts might be damaged when the valve needle 35 moves between the open and closed positions.

[0048] Therefore, when the valve needle 35 is in the closed position, the cylindrical distal section 39 and its sealing ring 52 fluidly disconnect the nozzle opening 45 from the main opening 50. Thus, when the valve needle 35 is in the closed position, any fuel in the space between the valve seat 36 and the distal end of the main opening 50 is prevented from leaking into the combustion chamber 14.

[0049] Therefore, when the valve needle 35 is in the open position, the cylindrical distal section 39 allows fuel to flow through the axial groove 63 to the nozzle orifice.

[0050] The main opening has a larger first diameter near the end of the axial groove 63 and a smaller second diameter in the region of the axial groove 63 and at the location where the main opening forms a continuous cylindrical surface facing the sealing ring 52 in the closed position of the valve needle 35.

[0051] An axially displaceable valve needle 35 is slidably received in a longitudinal opening 64 in an elongated valve housing 32. The valve needle 35 rests on a valve seat 36, preferably a tapered valve seat, in the closed position, and is lifted from the valve seat 35 in the open position. A fuel chamber 68 surrounds the valve needle 35 and leads to the valve seat 36. One or more lines 61 supply fuel to the fuel chamber 68. A sealing fluid line 65 supplies pressurized sealing fluid with a pressure higher than the fuel pressure to the opening where the valve needle 35 is journal-connected.

[0052] The nozzle orifice 45 points in a roughly radial direction.

[0053] In this embodiment, the circumferential groove 54 holds two or more sealing rings 52 to improve sealing efficiency.

[0054] In this embodiment, the ring-type partition 53 is a leak-proof ring-type partition to improve sealing efficiency.

[0055] This invention has been described in conjunction with various embodiments. However, by studying the drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed embodiments in practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "the" do not exclude multiple. The fact that certain measures are described in different dependent claims does not in itself indicate that these measures cannot be combined to achieve better results. 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 a large two-stroke turbocharged direct-flow scavenging internal combustion engine having a crosshead, the fuel valve (30) comprising: An elongated fuel valve housing (32) having a longitudinal axis (X), a proximal end (31) and a distal end (33). An axially displaceable valve needle (35) has a closed position and an open position. In the closed position, the valve needle (35) rests on a valve seat (36), and in the open position, the valve needle (35) is lifted off the valve seat (36). Atomizing nozzle (40) is disposed at the distal end (33) of the elongated valve housing (32). The atomizing nozzle (40) has a nozzle body that extends along the longitudinal axis (X) from a base (42) at a 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 housing (32). The nozzle body includes: The elongated portion (43), preferably, is a cylindrical elongated portion, extending between the base (42) and the closed distal end (44). Inlet (48), which leads to the base (42), for receiving liquid fuel from the fuel valve (30), Multiple nozzle openings (45). A main opening (50) extends longitudinally from the inlet (48) into the nozzle body. The valve needle (35) includes a cylindrical distal section (39) carried by the shank (38). When the valve needle (35) is in the closed position, the cylindrical distal section (39) is journal-connected to the distal portion of the main opening (50) in a tight-fitting manner, thereby fluidly disconnecting the nozzle opening (45) from the main opening (50). The feature is that the cylindrical distal section (39) is provided with a circumferential groove (54), and a sealing ring (52) is maintained in the circumferential groove (54). In the closed position of the valve needle (35), the main opening (50) has a continuous cylindrical surface facing the sealing ring (52), and In the open position of the valve needle (35), the main opening (50) has a discontinuous cylindrical surface facing the sealing ring (52), and the discontinuity in the discontinuous cylindrical surface is formed by a plurality of circumferentially spaced axial grooves (63).

2. The fuel valve (30) according to claim 1, wherein, The main opening has a larger first diameter near the axial groove (63) and a smaller second diameter in the region of the axial groove (63) and at the location where the main opening forms the continuous cylindrical surface facing the sealing ring (52) at the closed position of the valve needle (35).

3. The fuel valve (30) according to claim 1 or 2, wherein, The handle (38) has a smaller cross-sectional area than the cylindrical distal section (39).

4. The fuel valve (30) according to any one of claims 1 to 3, wherein, When the valve needle (35) is in the closed position, the cylindrical distal section (39) disconnects the opening of the nozzle orifice (45) from the portion of the main orifice (50) near the cylindrical distal section (39).

5. The fuel valve (30) according to any one of claims 1 to 4, wherein, When the valve needle (35) is in the open position, the cylindrical distal section (39) connects the opening of the nozzle orifice (45) with the portion of the main orifice (50) near the cylindrical distal section (39).

6. The fuel valve (30) according to any one of claims 1 to 5, wherein, The axially displaceable valve needle (35) is slidably received in a longitudinal opening (64) in the elongated valve housing (32), the valve needle (32) resting on the valve seat (36) in the closed position, preferably the valve needle (32) resting on the conical valve seat in the closed position, the valve needle (35) being lifted from the valve seat (36) in the open position, and preferably the valve needle (35) being biased toward the closed position in an elastic and / or fluid manner, and preferably the fuel chamber (68) surrounding the valve needle (35) and opening to the valve seat (36).

7. The fuel valve (30) according to any one of claims 1 to 6, wherein the fuel valve (30) includes a fuel inlet port in the elongated fuel valve housing (32) for connection to a liquid fuel source.

8. The fuel valve (30) according to any one of claims 1 to 7, wherein, The nozzle opening (45) points in a generally radial direction.

9. The fuel valve (30) according to any one of claims 1 to 8, wherein, Each of the nozzle openings (45) has a nozzle axis (I, II, III, IV, V), and the nozzle axis (I, II, III, IV, V) of each nozzle opening in the nozzle opening (45) is set to form an obtuse angle α with the longitudinal axis (X).

10. The fuel valve (30) according to claim 9, wherein, The radial components of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) are distributed on a circular sector with an arc of less than 120 degrees. Preferably, the radial components of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) are distributed approximately uniformly on a circular sector with an arc of less than 120 degrees. Preferably, the radial components of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) are distributed on a circular sector with an arc of less than 110 degrees. Preferably, the nozzle... The radial components of each nozzle axis in the nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) are distributed approximately uniformly on a circular sector with an arc of less than 110 degrees. More preferably, the radial components of each nozzle axis in the nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) are distributed on a circular sector with an arc of less than 100 degrees. More preferably, the radial components of each nozzle axis in the nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) are distributed approximately uniformly on a circular sector with an arc of less than 100 degrees.

11. The fuel valve (30) according to any one of claims 1 to 10, wherein the fuel valve (30) comprises three to twelve axial grooves (63).

12. The fuel valve (30) according to any one of claims 1 to 11, wherein, The circumferential groove (54) holds two or more sealing rings (52).

13. The fuel valve (30) according to any one of claims 1 to 11, wherein, The sealing ring (52) includes a ring-shaped partition (53), preferably, the sealing ring (52) includes a leak-proof ring-shaped partition.

14. A large two-stroke turbocharged direct-flow scavenging internal combustion engine with a crosshead, comprising a fuel valve (30) according to any one of claims 1 to 13.

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