Fuel valve and engine having the same

Abstract

A fuel valve for injecting fuel into a large two-stroke turbocharged uniflow-scavenged internal combustion engine, the fuel valve comprising: 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; and an atomizer nozzle arranged at the distal end of the elongated valve housing, the atomizer nozzle having a nozzle body comprising: a generally cylindrical portion; an inlet; a plurality of straight nozzle holes; a single straight main hole extending longitudinally from the inlet into the nozzle body, the straight nozzle holes being connected to the straight main hole by separate feed channels arranged at an angle to the straight main hole and the associated straight nozzle hole. The application also provides a large two-stroke turbocharged uniflow-scavenged internal combustion engine having a crosshead comprising a fuel valve.

Description

Technical Field

[0001] This disclosure relates to a fuel valve for injecting liquid fuel into the cylinder of a large turbocharged two-stroke DC scavenging internal combustion engine. Background Technology

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

[0003] These engines have a single exhaust valve in each cylinder, centrally located in the cylinder head at the top of the cylinder. The cylinder also features a piston-controlled scavenging port ring located in the lower region of the cylinder liner. Thus, the gas is always delivered from bottom to top through the cylinder, a process known as single-flow scavenging. The scavenging port is angled to create vortices in the gas within the combustion chamber.

[0004] Two or three fuel valves are arranged in the cylinder head around a centrally located exhaust valve, with the fuel valve nozzles protruding into the combustion chamber. Alternatively, the fuel valves may be arranged peripherally (i.e., not centrally) in the cylinder head, where the nozzle orifice is essentially guided by the swirl, away from the cylinder wall and into the combustion chamber. Sometimes, individual nozzle orifices may resist the swirl in the combustion chamber.

[0005] The nozzle is attached to the front or distal end of the fuel valve. The fuel valve includes an elongated housing, the proximal or distal end of which protrudes from the upper surface of the cylinder head, and the elongated fuel valve housing extends through the cylinder head, with the nozzle located at the front or distal end of the elongated fuel valve housing, thus protruding into the combustion chamber.

[0006] Known nozzles for large two-stroke diesel engines with crosshead nozzles typically have an elongated nozzle body comprising a cylindrical portion having a straight main bore extending from the base of the nozzle located at the proximal end of the nozzle body to a nozzle orifice located near the tip or distal end of the nozzle body. The tip or distal end may be rounded or flat, but must be closed, because the nozzle orifice must not point downwards toward the piston (when the piston is at top dead center, i.e., at the moment of fuel injection in a compression-ignition engine, the upper surface of the piston is very close to the tip of the nozzle). Therefore, the nozzle orifice is primarily oriented laterally relative to the main axis of the nozzle / fuel valve and is generally perpendicular to the main axis of the engine cylinder. Typically, each nozzle has three to seven nozzle orifices, all of which connect to the main bore.

[0007] Typically, known fuel valves for injecting liquid fuel are equipped with an axially displaceable valve needle that engages with a conical valve seat to control the fuel flow to the nozzle. Furthermore, the front portion of the valve needle includes a distal cylindrical section that is tightly received within the main bore and functions as a sliding valve to close the nozzle orifice when the valve needle is in the closed position. This significantly reduces the so-called needle valve pressure chamber volume—the residual volume of fuel in the space within the nozzle formed by the main bore. Without such a sliding valve arrangement, the amount of residual fuel in the main bore (and nozzle orifice) would drip into the combustion chamber after the fuel injection event, adversely affecting fuel consumption, reliability, and emissions.

[0008] Because the nozzle body protrudes into the combustion chamber, it is exposed to the hot gases, and various parts of the nozzle body thus reach relatively high temperatures, up to approximately 400°C. The incoming fuel is suitable for heavy oil engines and has a temperature of approximately 140°C. Therefore, the temperature of the incoming fuel leaving the nozzle through the nozzle orifice in the main orifice is significantly lower than the temperature of the gas surrounding the outer surface of the nozzle body. Consequently, the material of the nozzle body is exposed to a significant temperature gradient, leading to stress within the nozzle material.

[0009] Therefore, when the nozzle is exposed to the high operating temperature of the gas in the combustion chamber and the good cooling effect of the injected fuel, there is a risk of cracking in the nozzle positioning area, especially between the nozzle orifices, due to the thermal fatigue of the material.

[0010] This problem cannot be solved by simply increasing the distance between the nozzle orifices to increase the amount of material between them and reduce the temperature gradient, because increasing the nozzle diameter is highly undesirable as it could increase the heat transferred from the combustion chamber to the nozzle. Furthermore, it cannot be solved by simply increasing the radial spacing between the nozzle orifices, because the radial distribution of the nozzle orifices is limited to an angle of approximately 110° due to the two or three fuel valves positioned on the outer circumference of the cylinder head. This is especially true when a sliding valve is present in the nozzle, requiring the main orifice in the nozzle to have a certain diameter, thus limiting the wall thickness of the nozzle body. Moreover, in fuel valves with sliding valves in the nozzle body, if fuel is to be injected simultaneously from the nozzle orifices, the nozzle orifices must open at approximately the same axial distance from the base of the nozzle to the main orifice.

[0011] US5765755A discloses an injection rate shaping nozzle assembly for a fuel injector, comprising a closed nozzle valve element and a rate shaping control device including a method for overflowing a portion of the fuel to be injected to cause a predetermined time-varying change in the rate of fuel injected into the combustion chamber. An overflow circuit includes an overflow passage integrally formed in the nozzle valve element. The rate shaping control device may include an overflow acceleration chamber formed in the nozzle valve element for creating a rapid increase in the overflow flow rate. An overflow circuit purging device is provided to remove fuel from the overflow circuit and acceleration chamber between each injection event, thereby ensuring an unobstructed and efficient overflow fuel flow during the next overflow event. The purging device includes a purge passage formed by predetermined dimensions to restrict the flow of purge gases, thereby ensuring adequate removal of fuel from the injection overflow circuit while avoiding excessive purge gas flow. The purging passage may include an annular gap formed between the nozzle valve element and the nozzle housing wall, or alternatively, the purging passage may include an orifice passage formed in an internal portion of the nozzle valve element. Summary of the Invention

[0012] In view of the above, the object of the present invention is to provide a fuel valve for injecting liquid fuel into a large two-stroke single-flow scavenging internal combustion engine of the crosshead type, which overcomes or at least reduces the above-mentioned problems.

[0013] The above and other objectives are achieved by the fuel valve and engine according to embodiments of this application. Further implementations are apparent from the specification and drawings.

[0014] According to a first aspect, a fuel valve is provided for injecting liquid fuel into a large two-stroke turbocharged single-flow scavenging internal combustion engine having a crosshead, the fuel valve comprising:

[0015] The elongated fuel valve housing has a longitudinal axis, a proximal end, and a distal end.

[0016] An axially displaceable valve needle has a closed position and an open position. In the closed position, the valve needle rests on a valve seat; in the open position, the valve needle is raised from the valve seat.

[0017] The nozzle is located at the distal end of the elongated valve body.

[0018] The nozzle has a nozzle body that extends along a longitudinal axis from a base located at a proximal end of the nozzle body to a closed distal end of the nozzle body, the base being attached to a fuel valve (30).

[0019] The nozzle body includes an elongated, preferably cylindrical, portion extending between a base and a closed distal end.

[0020] The inlet, which leads to the base, is used to receive liquid fuel from the fuel valve.

[0021] Multiple straight nozzle orifices, each opening at a different radial angle to the outer surface of the nozzle body.

[0022] A single straight main bore extends longitudinally from the inlet into the nozzle body.

[0023] At least two of the straight nozzle orifices are connected to the straight main orifice via separate supply channels, the separate supply channels being arranged at an angle to the straight main orifice and the associated straight nozzle orifice.

[0024] The valve needle includes a distal portion having a cylindrical end portion carried by a shank and the cylindrical end portion being journal-connected in a tight-fitting manner to a straight main bore such that: when the valve needle is in the closed position, the separate supply channel is fluidly disconnected from the main straight bore.

[0025] By providing separate supply channels angled to the straight nozzle orifice and the main nozzle orifice, greater freedom is provided for selecting the angle of the straight nozzle orifice relative to the main axis and its position in the nozzle body material. This allows for selection of the nozzle orifice position and orientation, resulting in more nozzle body material between adjacent nozzle orifices. This reduces the thermal coefficient and thermal stress associated with crack formation without increasing the overall size of the nozzle, especially the diameter of the cylindrical portion of the nozzle.

[0026] According to a possible implementation of the first aspect, from the position where the associated individual supply channel is connected to the main orifice, the individual supply channel is guided away from the longitudinal axis at a first angle, thereby causing the "base" of the straight nozzle orifice to be arranged more radially outward, thus allowing a greater distance between adjacent straight nozzle orifices, and therefore allowing more nozzle body material between adjacent nozzle orifices. In this document, the "base" position is the location where the straight nozzle orifice is connected to the associated individual supply channel.

[0027] According to a possible implementation of the first aspect, from the position where the relevant straight nozzle orifice is connected to a separate supply channel, the straight nozzle orifice is guided to be away from the longitudinal axis at a second angle to the longitudinal axis, the second angle being greater than the first angle.

[0028] According to a possible implementation of the first aspect, the separate supply channel is a straight orifice, preferably with a rounded, i.e., spherical end, to reduce stress in the nozzle orifice material.

[0029] According to a possible implementation of the first aspect, when the valve needle is in the open position, the cylindrical end portion will have a separate supply channel fluidly connected to the main straight bore.

[0030] According to a possible implementation of the first aspect, when the valve needle is in the closed position, the cylindrical end portion covers the opening of the individual supply channel facing the straight main bore.

[0031] When the valve needle is in the open position, the cylindrical end portion does not cover the opening of the separate supply channel facing the straight main bore.

[0032] According to a possible implementation of the first aspect, a separate supply channel leads to the main bore at a given axial distance from the inlet, and the cylindrical end portion extends beyond the given axial distance in the closed position of the valve needle.

[0033] According to a possible implementation of the first aspect, an axially displaceable valve needle is slidably received in a longitudinal bore in an elongated valve housing. The valve needle rests on a valve seat in the closed position, the valve seat preferably being a conical valve seat. The valve needle is raised from the valve seat in the open position, and the valve needle is preferably biased toward the closed position. Preferably, the fuel chamber is arranged to surround the valve needle and open to the valve seat.

[0034] According to a possible implementation of the first aspect, the fuel valve includes a fuel inlet port located in an elongated fuel valve housing for connection to a liquid fuel source.

[0035] According to a possible implementation of the first aspect, the straight nozzle holes in the straight nozzle orifice have substantially equal cross-sectional areas or diameters, and preferably, all the straight nozzle holes in the straight nozzle orifice also have substantially equal lengths.

[0036] According to a possible implementation of the first aspect, the straight nozzle orifices in the straight nozzle orifice have equal diameters, and preferably, the individual supply channel has a diameter larger than the diameter of the straight nozzle orifice.

[0037] According to a possible implementation of the first aspect, a straight main bore is formed in a bushing, which is securely received in a bore in the valve body.

[0038] According to a possible implementation of the first aspect, the cylindrical end portion is hollow to form a fluid channel, which preferably extends to the outside of the handle at the proximal end and is preferably open in the axial direction at the distal end.

[0039] According to one possible implementation of the first aspect, the straight nozzle orifice leads to the cylindrical surface.

[0040] According to a possible implementation of the first aspect, a rounded transition surface is preferably arranged between the generally cylindrical surface of the nozzle body and the flat distal surface.

[0041] According to a possible implementation of the first aspect, the straight nozzle orifice leads to the cylindrical surface and / or transition surface.

[0042] According to one possible implementation of the first aspect, each of the straight nozzle orifices has a nozzle axis I, II, III, IV, V, and wherein the nozzle axes I, II, III, IV of each nozzle orifice are arranged at an obtuse angle α with the main direction X.

[0043] According to a possible implementation of the first aspect, the radial component of each of the nozzle axes I, II, III, IV, V relative to the main axis X is distributed, preferably approximately equally, on a circular sector with an arc of less than 120 degrees, the arc of which is preferably less than 110 degrees, or even more preferably less than 100 degrees.

[0044] According to a possible implementation of the first aspect, at least three of the straight nozzle holes are connected to the straight main hole via separate supply channels arranged at an angle to the straight main hole and the associated straight nozzle holes.

[0045] According to a second aspect, a large two-stroke turbocharged single-flow scavenging internal combustion engine with a crosshead is provided, the internal combustion engine including a fuel valve as described in the first aspect or any implementation thereof.

[0046] These and other aspects of the invention will become apparent from the embodiments described below. Attached Figure Description

[0047] In the following detailed sections of this disclosure, the invention will be described in more detail with reference to exemplary embodiments shown in the accompanying drawings, in which:

[0048] Figure 1 This is a front view of the front end and a side view of a large two-stroke unit-flow scavenged turbocharged engine according to an exemplary embodiment.

[0049] Figure 2 yes Figure 1 A front view of the rear end and the other side of the engine.

[0050] Figure 3 It is based on Figure 1 A schematic diagram of the engine and its intake and exhaust systems.

[0051] Figure 4 It is used in Figures 1 to 3 A cross-sectional view of an embodiment of the fuel valve in the engine used.

[0052] Figure 5 Is Figures 1 to 3 A cross-sectional view of another embodiment of the fuel valve used in an engine.

[0053] Figure 6 yes Figure 4 or Figure 5 A frontal perspective view of the nozzle of the fuel valve.

[0054] Figure 7 yes Figure 6 A cross-sectional view of the nozzle.

[0055] Figure 8 yes Figure 6 A cross-sectional view of the tip of the nozzle, wherein the distal cylindrical portion of the valve needle is in the open position.

[0056] Figure 9 yes Figure 8 The view shows the distal cylindrical portion of the valve needle in the closed position.

[0057] Figure 10 yes Figure 6 A three-dimensional view of the tip of the nozzle.

[0058] Figure 11 yes Figure 6 Another cross-sectional view of the nozzle tip, wherein the distal cylindrical portion of the valve needle is in the closed position, and

[0059] Figure 12 When viewed from the side of the piston Figure 5 The diagram illustrates the position of the fuel valve nozzle in the cylinder head, and shows the orientation of the nozzle orifice and the resulting fuel jet. Detailed Implementation

[0060] In the following detailed description, a fuel valve and a large two-stroke engine using the fuel valve will be described by way of exemplary embodiments. Figures 1 to 3 A large, low-speed turbocharged two-stroke internal combustion engine with a crankshaft 22 and a crosshead 23 is shown. Figure 3 A schematic diagram of a large, low-speed turbocharged two-stroke internal combustion engine with an intake and exhaust system is shown. In this exemplary embodiment, the engine has six cylinders arranged in a straight line (formed by cylinder liners 1). Large turbocharged two-stroke internal combustion engines typically have between five and sixteen cylinders arranged in a straight line, carried 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 for operating generators in power plants. The total output of the engine can be, for example, in the range of 5,000 kW to 110,000 kW.

[0061] The engine can be a two-stroke, single-flow diesel (compression ignition) engine, having a scavenging port 19 in the form of a piston control port located 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, making the engine a so-called unidirectional flow type. Scavenging gas flows from the scavenging receiver 2 to the scavenging ports 19 of the individual cylinders formed by the cylinder liner 1. The reciprocating piston 21 in the cylinder liner 1 compresses the scavenging gas, and fuel is injected through nozzles of two or three fuel valves 30 located in the cylinder head 26. Combustion then occurs, producing exhaust gas. When the exhaust valve 4 is open, the exhaust gas flows through the exhaust pipe 20 associated with the cylinder 1 into the exhaust gas receiver 3, and forward through the first exhaust duct 18 to the turbine 6 of the turbocharger 5, from which the exhaust gas is discharged through the second exhaust duct 7. The turbine 6 drives the compressor 9, supplied via the air inlet 10, through the shaft 8.

[0062] Compressor 9 delivers pressurized boosted air to boosted air duct 11 leading to boosted air receiver 2. Scavenging air in duct 11 passes through intercooler 12 for cooling the boosted air. The cooled boosted air then passes through auxiliary blower 16 driven by electric motor 17, which pressurizes the boosted air flow to boosted air receiver 2 under low or partial load conditions. At higher loads, turbocharger compressor 9 delivers sufficient compressed scavenging air, while auxiliary blower 16 is bypassed via check valve 15.

[0063] The cylinder is formed in the cylinder liner 1. The cylinder liner 1 is supported by the cylinder frame 25, which is supported by the engine frame 24.

[0064] Figure 4 An embodiment of one of two or three fuel valves 30 mounted in a through-hole in the cylinder head 26 of each cylinder is shown, wherein the rear end 31 of the fuel valve 30 protrudes from the upper side of the cylinder head 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., ethanol, methanol, diesel, heavy fuel oil) is delivered to the combustion chamber 14 via the nozzle 40 through the fuel valve 30 in a controlled and timed manner. Figure 4 The fuel valve 30 shown has an elongated outer housing 32, which has a head at its proximal end 31. The fuel valve 30 can be mounted in the cylinder head 26 in a known manner and connected to the fuel pump (not shown) of the internal combustion engine through this head.

[0065] The head located at the proximal end 31 includes a fuel inlet 83, which is in flow communication with a conduit extending through the valve body 32. An axially displaceable valve needle 35 is journal-connected in 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 portion of the valve needle 35 rests in a sealing manner on the valve seat 36. The valve needle is elastically biased toward the closed position by an elastic device, in this embodiment, formed by a coil spring 83. The raising of the valve needle 35 against the bias of the coil spring 83 is caused by the pressure of fuel supplied to the fuel valve 30 acting on the surface of the valve needle 35, or by the pressure of a piston or plunger operably connected to the valve needle 35. A fuel chamber 68 surrounds the valve needle 35 and opens to the valve seat 36.

[0066] The fuel valve 30 carries the nozzle 40 at its distal end 33. The nozzle 40 is configured such that the fuel valve 30 is mounted on the cylinder head 26 and the nozzle 40 protrudes into the combustion chamber 14 of the engine cylinder liner 1.

[0067] In this embodiment, the fuel valve includes an axially movable valve needle 35, which includes a tapered portion that engages with a tapered seat 36 in the longitudinal housing 32 of the fuel valve 30.

[0068] Figure 12 The diagram shows how the nozzle 40 is positioned on the outer periphery of the cylinder head 26, and the direction of fuel injection (which corresponds to the directions of axes I, II, III, IV, and V of the straight nozzle orifice 45 in the nozzle 40). The direction of the gas vortex in the combustion chamber is indicated by the curved dashed arrow 66.

[0069] Figure 5 A fuel valve 30 according to another embodiment is shown, which is similar to Figure 4 The embodiment differs in that the fuel valve 30 includes a 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. Other components of the fuel valve 30 and the nozzle 40 according to this embodiment are conceptually similar to... Figure 4 The fuel valve is the same.

[0070] Figures 6 to 11 The distal portions of nozzle 40 and valve needle 35 are shown in more detail.

[0071] The nozzle 40 has a nozzle body that extends from a base 42 at a proximal end to a closed distal end 44 forming the tip of the nozzle 40. A cylindrical portion 43 of the nozzle body extends from the base to the distal end 44. The nozzle body is made of a suitable material, for example, formed of a suitable alloy well known in the art.

[0072] Inlet 48 leads to base 42 for receiving liquid fuel from fuel valve 30 when valve needle 35 is in the open position. A single straight main bore 50 extends longitudinally from inlet 48 into the nozzle body. In this embodiment, the straight main bore 50 is formed in bushing 51, which is securely received in a bore 51 in the valve body, for example, by a shrink fitting. However, it should be understood that the nozzle can be constructed without bushing 51, such that the nozzle body is made of a single piece of material.

[0073] The closed distal end (tip end) 44 includes a generally flat end surface 47 having a circular or elliptical profile. The end surface 47 is connected to the cylindrical portion via a curved or rounded transition surface 46.

[0074] The nozzle 40 is provided with a plurality of straight nozzle holes 45. The nozzle 40 is provided with any desired number of nozzle holes 45, preferably between three and seven nozzle holes 45, even more preferably between three and six nozzle holes 45, and most preferably five or six nozzle holes 45. The nozzle 40 according to this embodiment is provided with five nozzle holes 45.

[0075] Each straight nozzle orifice 45 extends at a different radial angle toward the outer surface of the nozzle body 43 to create a fan-shaped fuel beam (e.g., when the fuel valve 30 is opened) Figure 12 (As shown) is injected into the combustion chamber. Each straight 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 to the transition surface 46.

[0076] Each of the nozzle orifices 45 has nozzle axes I, II, III, IV and V. Figure 10 The nozzle axes I, II, III, IV, and V of each of the nozzle orifices 45 are arranged at an obtuse angle α with respect to the main axis X. The obtuse angle α may be different for each of the nozzle orifices 45. The radial component of each of the nozzle axes I, II, III, IV, and V relative to the main axis X is distributed on a circular sector with an arc angle of less than 120 degrees, preferably less than 110 degrees, and even more preferably less than 100 degrees. The radial component of each of the nozzle axes (I, II, III, IV, and V) relative to the main axis X is distributed substantially uniformly on the circular sector to maximize the amount of nozzle body material between the individual nozzle orifices 45.

[0077] The base 42 is provided with an inlet port 48 for receiving fuel from the fuel valve 30. A main bore 50 extends from the inlet port 48 along the main axis X into the nozzle body and into the cylindrical portion 43, reaching a position near the distal end 44 of the nozzle body. The main bore 50 is connected to a plurality of individual supply channels 49, each supply channel 49 being connected to a nozzle orifice 45. The individual supply channels 49 are arranged at an angle to the axis of the main bore 50 and at an angle to the axis of the nozzle orifice 45, with the associated individual supply channel 49 connected to the nozzle orifice 45.

[0078] The cross-sectional area of ​​the main orifice 50 is approximately larger than the total cross-sectional area of ​​the supply channel 49. The total cross-sectional area of ​​the supply channel 49 is approximately equal to the total cross-sectional area of ​​the nozzle orifice 45.

[0079] Connecting the nozzle orifice 45 to the main orifice 50 using a separate supply channel 49 allows the nozzle orifice 45 to be arranged such that the amount of nozzle body material between the nozzle orifices 45 is maximized, while still allowing the axes I, II, III, IV and V of the nozzle orifice 45 to cover the desired circular sector with fuel jets.

[0080] In one embodiment, the inlet port 48 is formed by a hole with a diameter larger than that of the main hole 50. Alternatively, the inlet port 48 may have the same diameter as the main hole.

[0081] The nozzle 40 provides a wide distribution of nozzle orifices 45, and thus provides more nozzle material between the nozzle orifices 45, and therefore better resists crack formation. Furthermore, the nozzle 40 provides uniform inlet conditions for each nozzle orifice 45 to produce a substantially uniform fuel jet.

[0082] The valve needle 35 includes a distal portion comprising a cylindrical end portion 39 carried by a shank 38. The cylindrical end portion 39 is journal-connected in a tight-fitting manner to a straight main bore 50, so that when the valve needle 35 is in such a position... Figure 7 , Figure 9 and Figure 11 In the closed position, the individual supply channels 49 are fluidly disconnected from the main straight bore 50 because, when the valve needle 35 is in the closed position, the cylindrical end portion 39 covers the openings of each supply channel 49 toward the main straight bore 50. Therefore, when the valve needle 35 is in the closed position, any fuel leakage into the combustion chamber 14 is prevented from the space between the valve seat 36 and the distal end of the main bore 50.

[0083] The cylindrical end portion 39 is hollow to form a fluid passage 71 for fuel from the proximal side to the distal side of the cylindrical end portion 39. The fluid passage 71 opens to the outside of the handle 38 at the proximal end and opens distally in the axial direction.

[0084] When valve needle 35 is in the open position, such as Figure 8 As shown, since the cylindrical end portion 39 does not cover the opening of the separate supply channel toward the main straight hole 50, the cylindrical end portion 39 fluidly connects the separate supply channel 49 to the main straight hole 50.

[0085] A separate supply channel 49 leads to the main bore at a given axial distance from the inlet 48, and a cylindrical end portion 39 extends beyond the given axial distance in the closed position of the valve needle 35 to impede fuel flow to the separate supply channel 49.

[0086] In this embodiment, viewed from the location where the individual supply channel 49 connects to the main orifice 50, the individual supply channel 49 is directed at a first angle away from the longitudinal axis X, thereby forming a more radially outwardly positioned "base" of the straight nozzle orifice 45. This allows for a greater distance between adjacent straight nozzle orifices 45, and thus allows for more nozzle body material between adjacent straight nozzle orifices 45. In this context, the "base" location is the location where the straight nozzle orifice 45 connects to the individual supply channel 49.

[0087] In one embodiment, from the position where the associated nozzle orifice 45 is connected to the separate supply channel 49, the straight nozzle orifice 45 is guided to be at a second angle to the longitudinal axis X and away from the longitudinal axis X, the second angle being greater than the first angle.

[0088] According to a possible implementation of the first aspect, the individual supply channel 49 is a straight hole, preferably having a rounded, i.e., spherical end (“base” or near the “base”) to reduce stress in the nozzle orifice material.

[0089] This invention has been described in conjunction with various embodiments. However, those skilled in the art who practice the claimed invention will understand and implement other variations of the disclosed embodiments by studying the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. The fact that certain measures are set forth in mutually different dependent claims does not indicate that combinations of these measures cannot be used advantageously. 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 single-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, 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 raised from the valve seat (36). Atomizer nozzle (40) is disposed at the distal end (33) of the elongated fuel valve housing (32). The atomizer nozzle (40) has a nozzle body that extends along the longitudinal axis (X) from a base (42) located at a proximal end of the nozzle body to a closed distal end (44) of the nozzle body, the base (42) being attached to the fuel valve (30). The nozzle body includes: An elongated portion (43) extends between the base (42) and the closed distal end (44). An inlet (48) leading to the base (42) for receiving liquid fuel from the elongated fuel valve housing (32), Multiple straight nozzle holes (45), each straight nozzle hole (45) opening to the outer surface of the nozzle body at a different radial angle, A single straight main hole (50) extends longitudinally from the inlet (48) into the nozzle body. Its features are, At least three of the straight nozzle holes (45) are connected to the straight main hole (50) via separate supply channels (49), the separate supply channels (49) being arranged at an angle to the straight main hole (50) and the associated straight nozzle holes (45). The valve needle (35) includes a distal portion having a cylindrical end portion (39) carried by a shank (38), and the cylindrical end portion (39) is journal-connected in a tight-fitting manner to the straight main bore (50) such that: when the valve needle (35) is in the closed position, the separate supply channel (49) is fluidly disconnected from the straight main bore (50).

2. The fuel valve (30) according to claim 1, wherein, When the valve needle (35) is in the open position, the cylindrical end portion (39) fluidly connects the separate supply channel (49) to the straight main hole (50).

3. The fuel valve (30) according to claim 1 or 2, wherein, When the valve needle (35) is in the closed position, the cylindrical end portion (39) covers the opening of the separate supply channel (49) toward the straight main hole (50).

4. The fuel valve (30) according to claim 2, wherein, When the valve needle (35) is in the open position, the cylindrical end portion (39) does not cover the opening of the separate supply channel (49) toward the straight main hole (50).

5. The fuel valve (30) according to claim 1, wherein, The separate supply channel (49) leads to the straight main hole at a given axial distance from the inlet (48), and wherein the cylindrical end portion (39) extends beyond the given axial distance in the closed position of the valve needle (35).

6. The fuel valve (30) according to claim 1, wherein, An axially displaceable valve needle (35) is slidably received in a longitudinal bore (64) in the elongated fuel valve housing (32). The axially displaceable valve needle (35) rests on a valve seat (36) in the closed position, and is raised from the valve seat (36) in the open position. The axially displaceable valve needle (35) is biased toward the closed position. A fuel chamber (68) surrounds the axially displaceable valve needle (35) and opens to the valve seat (36).

7. The fuel valve (30) according to claim 1, comprising a fuel inlet port (34) located in the elongated fuel valve housing (32) for connection to a liquid fuel source.

8. The fuel valve (30) according to claim 1, wherein, All the straight nozzle holes (45) have at least one of the following: equal cross-sectional area, equal diameter and equal length.

9. The fuel valve (30) according to claim 1, wherein, The straight main hole (50) is formed in the bushing (51), which is securely received in the hole in the nozzle body.

10. The fuel valve (30) according to claim 1, wherein, The cylindrical end portion (39) is hollow to form a fluid channel (71) that opens to the outside of the handle (38) at the proximal end and opens distally in the axial direction.

11. The fuel valve (30) according to claim 1, wherein, The straight nozzle hole (45) leads to the outer surface of the elongated portion (43).

12. The fuel valve (30) according to claim 1, comprising a rounded transition surface (46) located between the outer surface of the elongated portion (43) and the flat distal surface (47) of the nozzle body.

13. The fuel valve (30) according to claim 12, wherein, The straight nozzle orifice (45) leads to the outer surface of the elongated portion (43) and / or to the transition surface (46).

14. The fuel valve (30) according to claim 1, wherein, Each of the straight nozzle holes (45) has a nozzle axis (I, II, III, IV, V), and wherein the nozzle axis (I, II, III, IV, V) of each of the straight nozzle holes (45) is arranged at an obtuse angle α with the longitudinal axis (X).

15. The fuel valve (30) according to claim 14, wherein, The radial component of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) is distributed on a circular sector with an arc of less than 120 degrees.

16. The fuel valve (30) according to claim 14, wherein, The radial component of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) is distributed on a circular sector with an arc of less than 110 degrees.

17. The fuel valve (30) according to claim 14, wherein, The radial component of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) is distributed on a circular sector with an arc of less than 100 degrees.

18. The fuel valve (30) according to claim 14 or 15, wherein, The radial component of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) is equally distributed on a circular sector with an arc of less than 120 degrees.

19. The fuel valve (30) according to any one of claims 14 to 16, wherein, The radial component of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) is equally distributed on a circular sector with an arc of less than 110 degrees.

20. The fuel valve (30) according to any one of claims 14 to 17, wherein, The radial component of each nozzle axis (I, II, III, IV, V) relative to the longitudinal axis (X) is equally distributed on a circular sector with an arc of less than 100 degrees.

21. A large two-stroke turbocharged single-flow scavenging internal combustion engine with a crosshead, comprising a fuel valve (30) according to any one of claims 1 to 20.

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