Supercharger cover device, engine system operation method, and supercharger cover device installation method
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-08-13
Smart Images
Figure JP2025043831_13082026_PF_FP_ABST
Abstract
Description
Cover device for supercharger, operation method of engine system, and installation method of cover device for supercharger
[0001] The present disclosure relates to a cover device for a supercharger used for a supercharger that can be driven by exhaust gas generated by combustion of a fuel that is lighter than air in a gaseous state, an operation method of an engine system including the supercharger provided with this cover device for a supercharger, and an installation method of this cover device for a supercharger. This application claims priority based on Japanese Patent Application No. 2025-020306 filed with the Japan Patent Office on February 10, 2025, and incorporates its content herein by reference.
[0002] In recent years, for the purpose of reducing emissions of carbon dioxide, a typical greenhouse gas, the use of decarbonized fuels that do not generate carbon dioxide even when burned instead of conventional fossil fuels has been promoted. Patent Document 1 discloses an exhaust system that sucks unburned decarbonized fuel (fuel leakage gas) leaked from a marine internal combustion engine into the inside of an exhaust duct provided above the marine engine room by a suction fan and exhausts it outside the marine engine room.
[0003] Japanese Patent Application Laid-Open No. 2023-171208
[0004] An engine system including an engine and a supercharger may adopt ammonia or hydrogen as a fuel instead of heavy oil as an alternative fuel. These have the characteristic of being lighter than air when vaporized. These fuels are difficult to completely burn in an engine, and the exhaust gas supplied to the supercharger may contain gaseous fuel (hereinafter referred to as gas fuel) vaporized in the engine as an unburned component. And when leakage of gas fuel occurs from the supercharger, for example, there is a possibility of adversely affecting the human body or the surrounding environment. However, the exhaust system described in Patent Document 1 does not cover the upper part of the supercharger with an exhaust hood (which communicates the inside of the engine room and the inside of the exhaust duct), and there is a risk that the gas fuel leaked from the supercharger will diffuse.
[0005] This disclosure has been made in view of the above-mentioned problems, and aims to provide a turbocharger cover device that can suppress diffusion when gaseous fuel leaks from the turbocharger, a method for operating an engine system equipped with a turbocharger on which this turbocharger cover device is installed, and a method for installing this turbocharger cover device.
[0006] To achieve the above objective, the turbocharger cover device according to the present disclosure is a turbocharger cover device used in a turbocharger that can be driven by exhaust gas generated by the combustion of a fuel that is lighter than air in its gaseous state, wherein the turbocharger includes a turbine including a turbine casing into which the exhaust gas flows, a compressor including a compressor casing into which intake air flows, and a silencer connected to the compressor casing for reducing noise generated when the intake air is introduced from the surroundings, wherein the turbocharger cover device is a cover that covers at least a part of the turbine casing from above, and includes a cover for defining a gas fuel retention space between the turbine casing and the gas fuel in the gaseous state where the gas fuel can be retained in the event of leakage, and is configured to draw the gas retained in the gas fuel retention space towards the silencer by the negative pressure of the compressor.
[0007] The turbocharger cover device of this disclosure can suppress the diffusion of gaseous fuel when it leaks from the turbocharger.
[0008] This is a schematic diagram showing an example of the engine system configuration. This is a schematic diagram showing the configuration of a turbocharger cover device and a turbocharger according to one embodiment. This is a diagram for explaining the first and second joints according to one embodiment. This is a diagram for explaining the third joint according to one embodiment. This is a perspective view of the turbocharger cover device according to one embodiment. This is a view of the turbocharger cover device shown in Figure 2, taken from arrow Z. This is a diagram for explaining the area over which the cover according to one embodiment covers the turbine casing. This is a schematic diagram showing the configuration of a turbocharger cover device according to several embodiments.
[0009] Hereinafter, a turbocharger cover device according to an embodiment of the present disclosure, a method of operating an engine system equipped with a turbocharger on which this turbocharger cover device is installed, and a method of installing this turbocharger cover device will be described with reference to the drawings. Such embodiments represent one aspect of the present disclosure and are not limiting, and can be modified at will within the scope of the technical idea of the present disclosure.
[0010] <Engine System> Figure 1 is a schematic diagram showing an example of the configuration of the engine system 100. Figure 2 is a schematic diagram showing the configuration of the turbocharger cover device 1 and the turbocharger 110 according to one embodiment. As illustrated in Figure 1, the engine system 100 includes a turbocharger 110, an engine 150, a control device 200, and a turbocharger cover device 1 according to one embodiment. In the embodiment illustrated in Figure 1, the engine system 100 further includes a concentration detection device 210.
[0011] <Supercharger> The supercharger 110 is configured to be driven by exhaust gas G generated by the combustion of fuel FL, which is lighter than air in its gaseous state. Fuel FL is not particularly limited as long as it is lighter than air in its gaseous state, for example, ammonia fuel or hydrogen fuel. In this disclosure, the case in which fuel FL is liquid ammonia fuel will be explained as an example. However, this disclosure does not limit fuel FL to liquid. For example, fuel FL may be ammonia gas or hydrogen gas.
[0012] As illustrated in Figures 1 and 2, the supercharger 110 includes a turbine 112, a compressor 114, a silencer 116, a rotating shaft 118, and a bearing base 120. In one embodiment, the rotating shaft 118 coaxially connects the turbine 112 (turbine rotor 122 of the turbine 112) and the compressor 114 (impeller 140 of the compressor 114), and the rotation axis O1 of the turbine 112 and the rotation axis O2 of the compressor 114 are the same straight line.
[0013] Hereinafter, the direction in which the rotation axis O1 of the turbine 112 (the rotation axis O2 of the compressor 114) extends will be defined as the axial direction D1, the direction perpendicular to the axial direction D1 and extending from the rotation axis O1 will be defined as the radial direction D2, and the direction of rotation around the rotation axis O1 will be defined as the circumferential direction D3. Of the axial direction D1, the direction from the turbine 112 side toward the compressor 114 side (the direction from top to bottom in the plane of Figure 2) will be defined as one side of the axial direction D1, and the direction from the compressor 114 side toward the turbine 112 side (the direction from bottom to top in the plane of Figure 2) will be defined as the other side of the axial direction D1. Of the radial direction D2, the direction toward the rotation axis O1 will be defined as the inside of the radial direction D2, and the direction away from the rotation axis O1 will be defined as the outside of the radial direction D2.
[0014] The turbine 112 is rotationally driven by exhaust gas G supplied from the engine 150. As illustrated in Figure 2, the turbine 112 includes a turbine rotor 122 that rotates with the energy of the exhaust gas G, and a turbine casing 124 into which the exhaust gas G flows, and which is configured to rotatably house the turbine rotor 122. In one embodiment, the turbine 112 is a radial turbine. In some embodiments, the turbine 112 is an axial turbine.
[0015] The turbine casing 124 is connected to an inlet pipe 160 through which exhaust gas G flows into the turbine casing 124, and an outlet pipe 162 through which exhaust gas G flows out of the turbine casing 124. The turbocharger 110 has a first joint 125 where the turbine casing 124 and the inlet pipe 160 are connected to each other, and a second joint 127 where the turbine casing 124 and the outlet pipe 162 are connected to each other.
[0016] Figure 3 is a diagram illustrating a first joint 125 and a second joint 127 according to one embodiment. As illustrated in Figure 3, the turbine casing 124 includes an inlet-side flange surface 130 where an inlet 121 into which exhaust gas G flows in is formed, and an outlet-side flange surface 132 where an outlet 123 into which exhaust gas G flows out is formed. An exhaust gas flow path 131 is formed inside the turbine casing 124 through which exhaust gas G flows in the order of inlet 121, turbine rotor 122, and outlet 123. The first joint 125 is formed when the inlet-side flange surface 130 and the flange surface 164 of the inlet pipe 160 on the turbine casing 124 side come into contact with each other. The second joint 127 is formed when the outlet-side flange surface 132 and the tip surface 166 of the outlet pipe 162 on the turbine casing 124 side come into contact with each other. The second joint 127 is located on the other side of the axial direction D1 than the first joint 125. In one embodiment, the first joint 125 is located below the rotation axis O1 in order to suppress interference with the supercharger cover device 1.
[0017] The turbine casing 124 is connected to the bearing base 120. The supercharger 110 has a third joint 129, which is the portion where the turbine casing 124 and the bearing base 120 are connected to each other. Figure 4 is a diagram illustrating the third joint 129 according to one embodiment. As illustrated in Figure 4, the turbine casing 124 includes a scroll section 134 which is part of the exhaust gas passage 131 and defines a vortex-shaped scroll passage 133 for guiding exhaust gas G to the turbine rotor 122. The third joint 129 is formed by the contact between the turbine-side connection surface 136 on the other side of the bearing base 120 in the axial direction D1 and the wall surface 138 on one side of the scroll section 134 of the turbine casing 124 in the axial direction D1.
[0018] As described above, the compressor 114 is connected to the turbine 112 by a rotating shaft 118, and the power of the rotationally driven turbine 112 is transmitted via the rotating shaft 118 to compress the intake air A to the engine 150. As illustrated in Figure 2, the compressor 114 includes an impeller 140 coaxially connected to the turbine rotor 122 by a rotating shaft 118, which is driven by the rotation of the turbine rotor 122 to compress the intake air A, and a compressor casing 142 into which the intake air A flows, which houses the impeller 140. The compressor casing 142 is connected to a bearing base 120 and is located on the opposite side of the bearing base 120 from the turbine casing 124 in the axial direction D1. In one embodiment, the compressor 114 is a centrifugal compressor.
[0019] As illustrated in Figure 2, the silencer 116 is connected to one side of the compressor casing 142 in the axial direction D1. The silencer 116 is fastened by the compressor casing 142. The silencer 116 has a cylindrical shape and extends along the axial direction D1. When the impeller 140 rotates, the silencer 116 takes in intake air A from the outer circumference (outside the radial direction D2). The intake air A taken into the silencer 116 then flows into the compressor casing 142. The silencer 116 is designed to reduce the noise generated when intake air A is introduced from around the silencer 116 by a silencer element (sound-absorbing material) provided inside the silencer 116.
[0020] As illustrated in Figure 2, the bearing base 120 is located between the turbine 112 and the compressor 114 and houses a bearing 144 that rotatably supports a rotating shaft 118 connecting the turbine rotor 122 of the turbine 112 and the impeller 140 of the compressor 114. The bearing base 120 is positioned at the center of gravity of the supercharger 110 in the axial direction D1. The bearing base 120 is placed on the floor surface g, which is the mounting surface on the engine, and is configured to support at least a portion of the load of the supercharger 110.
[0021] <Engine> The engine 150 is configured to perform fuel combustion operation by burning fuel FL, and discharges exhaust gas G by performing fuel combustion operation. In the embodiment illustrated in Figure 1, the engine 150 includes a cylinder 152 in which a combustion chamber 151 is formed, and a fuel injector 154 that injects fuel FL into the combustion chamber 151. The engine 150 is configured such that intake air A, compressed by the supercharger 110, flows into the combustion chamber 151. The intake air A that flows into the combustion chamber 151 is mixed with fuel FL injected from the fuel injector 154. Furthermore, in addition to fuel combustion operation, the engine 150 is configured to perform diesel operation by burning diesel fuel DF. In one embodiment, the fuel injector 154 injects diesel fuel DF instead of gaseous fuel F.
[0022] <Control Device> The control device 200 controls the operation of the engine 150. In the embodiment illustrated in Figure 1, the control device 200 is electrically connected to the engine 150 and instructs the engine 150 whether to perform fuel combustion operation or diesel operation. The engine 150 performs fuel combustion operation or diesel operation according to the instructions of the control device 200. Such a control device 200 is a computer such as an electronic control device, and includes, for example, a processor such as a CPU or GPU (not shown), memory such as ROM or RAM, and an I / O interface. The control device 200 realizes each of its functional units by having the processor operate (calculate, etc.) according to the instructions of the program loaded into memory.
[0023] <Concentration Detection Device> The concentration detection device 210 detects the concentration (ammonia concentration) of gas fuel F in the gas fuel retention space 3 (described later). In the configuration illustrated in Figure 1, the control device 200 is electrically connected to the concentration detection device 210, and can obtain the concentration of gas fuel F in the gas fuel retention space 3 from the concentration detection device 210.
[0024] <Turbocharger Cover Device> (Configuration) A turbocharger cover device 1 according to one embodiment will be described. As shown in Figure 2, the turbocharger cover device 1 includes a cover 2 that covers at least a part of the turbine casing 124 from above. Figure 5 is a perspective view of the cover 2 according to one embodiment. The cover 2 is formed by processing a metal plate such as a galvanized steel plate or an iron plate. As a specific example, the cover 2 is a welded structure formed by welding a metal plate. In one embodiment, as illustrated in Figure 5, the cover 2 protrudes in one direction and has a curved shape that curves in a convex shape so that the outer shape changes smoothly. However, this disclosure does not limit the outer shape of the cover 2 to a curved shape.
[0025] In one embodiment, as shown in Figure 2, the cover 2 includes a base end 2a located on the other side of the axial direction D1 from the turbine casing 124. The cover 2 extends from the base end 2a toward one side of the axial direction D1, defining a gas fuel retention space 3 between it and the turbine casing 124 where gas fuel F leaked from the supercharger 110 can be retained.
[0026] The turbocharger cover device 1 is configured to draw gas Ax, which is accumulating in the gas fuel retention space 3, towards the silencer 116 by the negative pressure of the compressor 114. In one embodiment, the cover 2 includes a tip 2b that is positioned to overlap with the silencer 116 in the axial direction D1. The cover 2 extends from the base end 2a on the turbine casing 124 side toward the tip 2b on the silencer 116 side, so as to cover at least a portion of the silencer 116 from above. That is, the tip 2b of the cover 2 is located directly above the silencer 116 or radially outside the silencer 116 in the direction D2. In the axial direction D1, the cover 2 covers the entire turbine casing 124, the entire bearing base 120, the entire compressor casing 142, and a portion of the silencer 116 from above.
[0027] In one embodiment, as shown in Figure 2, the cover 2 includes a base-side return portion 4 extending inward in the radial direction D2 from the base end 2a, and a tip-side return portion 6 extending inward in the radial direction D2 from the tip end 2b. Each of the base-side return portion 4 and the tip-side return portion 6 is integrally formed with the cover 2. In one embodiment, the cover 2 is attached to the bearing base 120 via a support member 40. As described above, the bearing base 120 is located at the center of gravity of the supercharger 110 in the axial direction D1 and is in contact with the floor surface g, so it is a part of the supercharger 110 that experiences relatively little vibration. The support member 40 is, for example, a rod-shaped member extending outward in the radial direction D2 from the bearing base 120.
[0028] Figure 6 is a view of the turbocharger cover device 1 (cover 2 and lagging 10) shown in Figure 2, viewed from arrow Z (the other side of the axial direction D1). In one embodiment, as shown in Figure 6, the cover 2 covers the entire upper portion 124a of the turbine casing 124 from above when viewed from the axial direction D1. In some embodiments, the cover 2 covers a portion of the upper portion 124a of the turbine casing 124 from above when viewed from the axial direction D1.
[0029] Figure 7 is a diagram illustrating the extent to which the cover 2 covers the turbine casing 124 according to one embodiment, and is a view of the cover 2 from above. In one embodiment, as illustrated in Figure 7, the cover 2 covers 10% or more of the length L in the axial direction D1 of the silencer 116 from above. More specifically, the cover 2 covers 10% or more and 50% or less of the length L in the axial direction D1 of the silencer 116 from above. In some embodiments, the cover 2 covers 10% or more and 90% or less of the length L in the axial direction D1 of the silencer 116 from above.
[0030] In one embodiment, as shown in Figure 7, when viewed from above, the turbine casing 124, the bearing base 120, and the compressor casing 142 are each located within the area 5 enclosed by the cover 2 (the area enclosed by the dashed line in Figure 7). A portion of the silencer 116 is included within the area 5 enclosed by the cover 2.
[0031] In one embodiment, as shown in Figure 7, the cover 2 covers the entire first joint 125, the entire second joint 127, and the entire third joint 129 from above. In some embodiments, the cover 2 covers at least one of the entire first joint 125, the entire second joint 127, and the entire third joint 129 from above.
[0032] In one embodiment, as shown in Figure 2, the ceiling surface 8 of the cover 2 facing the gas fuel retention space 3 has an inclined surface that slopes upward from the turbine casing 124 side toward the silencer 116 side. The entire ceiling surface 8 from the base end 2a to the tip end 2b is an inclined surface. In some embodiments, at least a portion of the ceiling surface 8 is an inclined surface.
[0033] In one embodiment, as shown in Figure 2, the supercharger cover device 1 further includes a heat-shielding lagging 10 located radially D2 inward from the cover 2 and surrounding the turbine casing 124. The lagging 10 has an opening 11 that opens upward. The opening 11 may be a slit or a hole that divides the lagging 10. The material of the lagging 10 is not particularly limited; the lagging 10 may be a hard lagging made of a hard material such as metal, or a soft lagging made of a soft material such as glass wool.
[0034] (Operation and Effects) The operation and effects of the turbocharger cover device 1 according to one embodiment will be described. High-temperature exhaust gas G (approximately 400 to 600 degrees Celsius) discharged from the engine 150 flows into the turbine casing 124 of the turbocharger 110, but the temperature of this exhaust gas G decreases (approximately 200 to 300 degrees Celsius) when it flows out of the turbine casing 124. As a result, the turbine casing 124 undergoes large changes in length and volume due to thermal expansion, which can cause leakage of exhaust gas G. In particular, there is a high possibility of exhaust gas G leakage occurring in the parts where the first joint 125, the second joint 127, and the third joint 129 are formed. Furthermore, the exhaust gas G may contain gaseous fuel F, which is vaporized fuel FL that was not completely burned in the engine 150. In other words, there is a possibility that gaseous fuel F (ammonia gas) may leak from the turbine 112.
[0035] According to one embodiment, since the cover 2 covers the entire turbine casing 124 from above, even if gaseous fuel F leaks from the turbine 112, it is retained in the gaseous fuel retention space 3, preventing the gaseous fuel F from diffusing into the external space 180 of the supercharger 110 (excluding the gaseous fuel retention space 3), such as the engine room. Furthermore, since the cover 2 covers a part of the silencer 116, the gaseous fuel F in the gaseous fuel retention space 3 is drawn into the silencer 116 as intake air A by the negative pressure of the compressor 114 and can be burned in the engine 150. In other words, the exhaust gas containing the gaseous fuel F is recirculated. Therefore, when gaseous fuel F leaks from the supercharger 110, diffusion into the external space 180 can be suppressed.
[0036] Furthermore, this disclosure is not limited to the cover 2 covering a portion of the silencer 116 from above. If the unburned gaseous fuel F in the gaseous fuel retention space 3 can be drawn into the silencer 116 by the negative pressure of the compressor 114, the tip 2b of the cover 2 may be located on the other side of the silencer 116 in the axial direction D1.
[0037] According to one embodiment, the cover 2 extends from the turbine casing 124 side toward the silencer 116 side so as to cover 10% or more of the length of the silencer 116 in the axial direction D1 from above. Therefore, without adding any members other than the cover 2, most of the gas Ax accumulating in the gas fuel retention space 3 can be drawn into the silencer 116.
[0038] According to one embodiment, since the cover 2 covers from above a portion of the silencer 116 that is 10% or more and 50% or less of the length D1 in the axial direction, it is possible to ensure that a certain amount of intake air A is drawn in from the external space 180. Since the intake air A drawn in from the external space 180 is at a lower temperature than the gas Ax that remains in the gas fuel retention space 3, it is possible to draw in most of the gas Ax that remains in the gas fuel retention space 3 into the silencer 116 while suppressing the rise in intake air temperature caused by the gas Ax that remains in the gas fuel retention space 3.
[0039] According to one embodiment, since the ceiling surface 8 of the cover 2 is an inclined surface, the gas fuel F (ammonia gas) in the gas fuel retention space 3 can be moved along the ceiling surface 8 toward the silencer 116.
[0040] According to one embodiment, since the turbocharger cover device 1 includes lagging 10, even if high-pressure gaseous fuel F leaks from the turbine 112, the lagging 10 can reduce the pressure to, for example, atmospheric pressure. Furthermore, since an opening 11 is formed in the lagging 10, the leaked gaseous fuel F can be reduced in pressure and guided into the gaseous fuel retention space 3.
[0041] According to one embodiment, the entirety of the first joint 125, the entirety of the second joint 127, and the entirety of the third joint 129, which are all likely to leak gas fuel F, are covered from above by the cover 2. This makes it possible to suppress the diffusion of gas fuel F leaked from the turbocharger 110 into the external space 180.
[0042] According to one embodiment, the cover 2 covers the entire upper portion 124a of the turbine casing 124 from above. That is, since the lower portion of the turbine casing 124 is open to the external space 180, it is possible to suppress the diffusion of the gas fuel F into the external space 180 while dissipating heat to the external space 180 (while suppressing the temperature rise of the supercharger 110). According to one embodiment, since the cover 2 includes the base end side return portion 4 and the tip end side return portion 6, it is possible to suppress the diffusion of the gas fuel F into the external space 180.
[0043] Note that the present disclosure is not limited to the cover 2 covering the entire turbine casing 124 from above. In some embodiments, the cover 2 covers at least one of the first joint portion 125, the second joint portion 127, the third joint portion 129, and the opening 11 of the lagging 10 from above. In some embodiments, the base end 2a of the cover 2 is positioned to overlap the turbine casing 124 in the axial direction D1. That is, the base end 2a of the cover 2 is positioned directly above the turbine casing 124 or outside the turbine casing 124 in the radial direction D2.
[0044] Although not shown, in some embodiments, the turbine casing 124 includes an inlet side casing connected to the inlet pipe 160 and forming a turbine chamber for housing the turbine rotor 122, and an outlet side casing connected to the outlet pipe 162 and defining a downstream side of the exhaust gas flow path 131 relative to the turbine chamber. And the cover 2 covers from above the portion where the inlet side casing and the outlet side casing are connected to each other.
[0045] In one embodiment, the cover 2 extends from the turbine casing 124 side toward the silencer 116 side so as to cover a part of the silencer 116 from above, thereby enabling the turbocharger cover device 1 to draw in gas Ax accumulating in the gas fuel retention space 3 toward the silencer 116 side by the negative pressure of the compressor 114. However, this disclosure is not limited to this embodiment. Figure 8 is a schematic diagram showing the configuration of the turbocharger cover device 1 according to several embodiments. In the embodiment illustrated in Figure 8, the tip 2b of the cover 2 is located above the bearing base 120 so as to overlap with the bearing base 120 in the axial direction D1. In other words, the cover 2 does not extend from the base end 2a to above the silencer 116. The turbocharger cover device 1 further includes a draw-in pipe 30 configured to draw in gas Ax accumulating in the gas fuel retention space 3 toward the silencer 116 side by the negative pressure of the compressor 114. The intake pipe 30 has an intake channel formed inside through which the gas Ax accumulating in the gas fuel retention space 3 flows, and it connects the gas fuel retention space 3 with the space above the silencer 116 (part of the external space 180). With this configuration, the gas Ax accumulating in the gas fuel retention space 3 can be drawn into the silencer 116 via the intake pipe 30.
[0046] <Engine System Operation Method> An example of the operation method of the engine system 100 shown in Figure 1 will be described. The operation method of the engine system 100 according to one embodiment includes a diesel operation execution step S1 in which diesel operation is performed when fuel combustion operation stops. To give a specific example, the control device 200 instructs the engine 150 to stop fuel combustion operation, and then instructs the engine 150 to perform diesel operation. In other words, the engine system 100 is configured to automatically perform diesel operation, burning oil fuel or LNG, etc., as fuel when fuel combustion operation stops.
[0047] In one embodiment, the diesel operation execution step S1 performs diesel operation until the concentration of the gaseous fuel F (ammonia concentration) detected by the concentration detection device 210 becomes equal to or less than a preset threshold value. To give a specific example, after the control device 200 instructs the engine 150 to stop the fuel combustion operation, it instructs the engine 150 to perform diesel operation until the concentration of the gaseous fuel F (ammonia concentration) in the gaseous fuel retention space 3 becomes equal to or less than the threshold value.
[0048] According to the operation method of the engine system 100 according to one embodiment, the operation of the engine system 100 can be stopped after reducing the remaining amount of the gaseous fuel F in the engine 150 and the supercharger 110. Even if the gaseous fuel F leaks from the supercharger 110, this leaked gaseous fuel F can be drawn into the engine 150 by diesel operation and burned.
[0049] According to the operation method of the engine system 100 according to one embodiment, even if the gaseous fuel F leaks from the supercharger 110, diesel operation is performed until the concentration of the gaseous fuel F (ammonia concentration) in the gaseous fuel retention space 3 becomes equal to or less than the threshold value, so that the amount of the gaseous fuel F diffusing into the external space 180 can be suppressed.
[0050] <Installation Method of Cover Device for Supercharger> The installation method of the cover device 1 for the supercharger will be described. The installation method of the cover device 1 for the supercharger according to one embodiment includes an attachment step S11 of attaching the cover 2 to the bearing base 120 via the support member 40. The support member 40 may be provided on the bearing base 120 in a detachable manner in advance, or may be provided on the cover 2 in advance.
[0051] According to the installation method of the cover device 1 for the supercharger according to one embodiment, the cover device 1 for the supercharger capable of suppressing diffusion to the external space 180 when the gaseous fuel F leaks from the turbine 112 can be easily installed on the supercharger 110. Further, according to such a method, it is easy to retrofit the cover device 1 for the supercharger to an existing engine system.
[0052] The content described in each of the above embodiments is understood as follows, for example.
[0053] [1] The turbocharger cover device (1) according to the present disclosure is a turbocharger cover device used in a turbocharger (110) that can be driven by exhaust gas (G) generated by the combustion of a fuel (FL) that is lighter than air in its gaseous state, the turbocharger includes a turbine (112) including a turbine casing (124) into which the exhaust gas flows, a compressor (114) including a compressor casing (142) into which intake air (A) flows, and a silencer (116) connected to the compressor casing for reducing noise generated when the intake air is introduced from the surroundings, the turbocharger cover device is a cover that covers at least a part of the turbine casing from above, and includes a cover (2) for defining a gas fuel retention space (3) between the turbine casing and the gaseous fuel (F) that can be retained in the event of leakage. The gas (Ax) remaining in the gas fuel retention space is configured to be drawn towards the silencer side by the negative pressure of the compressor.
[0054] According to the configuration described in [1] above, even if gas fuel leaks from the turbocharger, it is retained in the gas fuel retention space, preventing the gas fuel from diffusing. Furthermore, the gas fuel in the gas fuel retention space can be drawn into the silencer as intake air by the negative pressure of the compressor and burned. Therefore, diffusion can be suppressed when gas fuel leaks from the turbocharger.
[0055] [2] In some embodiments, in the configuration described in [1] above, the cover extends from the turbine casing side toward the silencer side so as to cover at least a portion of the silencer from above.
[0056] According to the configuration described in [2] above, since the cover extends to the silencer, it is possible to draw the gas accumulating in the gas fuel stagnation space into the silencer. Furthermore, the gas accumulating in the gas fuel stagnation space can be drawn into the silencer without adding any components other than the cover.
[0057] [3] In some embodiments, in the configuration described in [2] above, at least a portion of the ceiling surface (8) of the cover facing the gas fuel retention space has an inclined surface that slopes upward from the turbine casing side toward the silencer side.
[0058] According to the configuration described in [3] above, the gas fuel in the gas fuel retention space can be moved toward the silencer.
[0059] [4] In some embodiments, in the configuration described in [2] or [3] above, the cover covers from above a portion of the silencer that is 10% or more of the length of the compressor in the axial direction (D1).
[0060] According to the configuration described in [4] above, most of the gas remaining in the gas fuel storage space can be drawn into the silencer.
[0061] [5] In some embodiments, in the configuration described in [4] above, the cover covers from above a portion of the silencer that is 10% or more and 50% or less of the axial length of the compressor.
[0062] According to the configuration described in [5] above, it is possible to draw most of the gas remaining in the gas fuel retention space into the silencer while suppressing the rise in intake air temperature caused by the gas remaining in the gas fuel retention space.
[0063] [6] In some embodiments, in the configuration described in any one of [1] to [5] above, the supercharger further includes a rotating shaft (118) that coaxially connects the turbine and the compressor, and a bearing base (120) that houses a bearing (144) that rotatably supports the rotating shaft, wherein the turbine casing is connected to an inlet pipe (160) for introducing the exhaust gas into the turbine casing, an outlet pipe (162) for releasing the exhaust gas out of the turbine casing, and the bearing base, and the portion where the turbine casing and the inlet pipe connect to each other is designated as a first joint (125), the portion where the turbine casing and the outlet pipe connect to each other is designated as a second joint (127), and the portion where the turbine casing and the bearing base connect to each other is designated as a third joint (129), wherein the cover covers at least one of the first joint, the second joint, and the third joint from above.
[0064] According to the configuration described in [6] above, at least one of the first joint, second joint, and third joint, which are most likely to leak gas fuel, is covered from above by the cover. This makes it possible to suppress the diffusion of gas fuel leaked from the turbocharger.
[0065] [7] In some embodiments, the configuration described in [1] above, the supercharger cover device further comprises a draw-in pipe (30) configured to draw the gas remaining in the gas fuel retention space to the silencer side by the negative pressure of the compressor.
[0066] According to the configuration described in [7] above, the gas remaining in the gas fuel storage space can be drawn into the silencer via the intake pipe.
[0067] [8] A method for operating an engine system according to the present disclosure is a method for operating an engine system (100) comprising a supercharger (110), a supercharger cover device (1) described in any one of [1] to [7] above, and an engine (150) that discharges the exhaust gas flowing into the turbine casing, the method comprising step (S1) of performing a diesel operation in which diesel fuel is burned in the engine when the fuel combustion operation in which the engine burns the fuel stops.
[0068] According to the configuration described in [8] above, the engine system can be shut down after reducing the amount of gaseous fuel remaining in the engine and supercharger.
[0069] [9] In some embodiments, in the configuration described in [8] above, the engine system further comprises a concentration detection device (210) for detecting the concentration of the gas fuel in the gas fuel retention space, and the step of performing diesel operation is to perform diesel operation until the concentration of the gas fuel detected by the concentration detection device falls below a preset threshold.
[0070] According to the configuration described in [9] above, even if gas fuel leaks from the turbocharger, diesel operation is carried out until the concentration of gas fuel detected by the concentration detection device falls below a threshold, thereby suppressing the amount of gas fuel that diffuses.
[0071]
[10] A method for installing a turbocharger cover device according to the present disclosure is a method for installing a turbocharger cover device (1) used in a turbocharger (110) that can be driven by exhaust gas generated by the combustion of a fuel that is lighter than air in its gaseous state, wherein the turbocharger includes a turbine including a turbine casing into which the exhaust gas flows, a compressor including a compressor casing into which intake air flows, a silencer connected to the compressor casing for reducing noise generated when the intake air is introduced from the surroundings, a rotating shaft coaxially connecting the turbine and the compressor, and a bearing base housing a bearing that rotatably supports the rotating shaft, wherein the method for installing the turbocharger cover device includes the step (S11) of attaching a cover to the bearing base via a support member, the cover which covers at least a part of the turbine casing from above, and which defines a gas fuel retention space between the turbine casing and the gas fuel in the event of leakage of the gaseous fuel.
[0072] According to the method described in
[10] above, a turbocharger cover device capable of suppressing diffusion when gaseous fuel leaks from the turbocharger can be easily installed on the turbocharger. The turbocharger cover device according to this disclosure is more compact than the exhaust system described in Patent Document 1, and is also advantageous in that it is easy to add to an existing engine system.
[0073] 1. Supercharger cover device 2. Cover 2a. Base end 2b. Tip end 3. Gas fuel retention space 4. Base end return section 5. Area enclosed by the cover 6. Tip end return section 8. Ceiling surface 10. Lagging 11. Opening 30. Inlet pipe 40. Support member 100. Engine system 110. Supercharger 112. Turbine 114. Compressor 116. Silencer 118. Rotating shaft 120. Bearing base 121. Inlet 122. Turbine rotor 123. Outlet 124. Turbine casing 125. First joint 127. Second joint 129. Third joint 130. Inlet side flange surface 131. Exhaust gas passage 132. Outlet side flange surface 133. Scroll passage 134. Scroll section 136. Turbine side connection surface 138. Scroll section wall 140 Impeller 142 Compressor casing 144 Bearing 150 Engine 151 Combustion chamber 152 Cylinder 154 Fuel injector 160 Inlet pipe 162 Outlet pipe 164 End surface of inlet pipe 166 End surface of outlet pipe 180 External space 200 Control device 210 Concentration detection device A Intake Ax Gas D1 Axial direction D2 Radial direction D3 Circumferential direction DF Diesel fuel F Gas fuel FL Fuel G Exhaust gas O1 Rotation axis of turbine O2 Rotation axis of compressor S1 Diesel operation execution step S11 Installation step g Floor surface
Claims
1. A turbocharger cover device used in a turbocharger that can be driven by exhaust gas generated by the combustion of a fuel that is lighter than air in its gaseous state, wherein the turbocharger includes a turbine including a turbine casing into which the exhaust gas flows, a compressor including a compressor casing into which intake air flows, and a silencer connected to the compressor casing for reducing noise generated when the intake air is introduced from the surroundings, and the turbocharger cover device is a cover that covers at least a part of the turbine casing from above, and comprises a cover for defining a gas fuel retention space between the turbine casing and the gas fuel in the gaseous state where the gas fuel can be retained in the event of leakage, and is configured to draw the gas retained in the gas fuel retention space towards the silencer by the negative pressure of the compressor.
2. The turbocharger cover device according to claim 1, wherein the cover extends from the turbine casing side toward the silencer side so as to cover at least a portion of the silencer from above.
3. The turbocharger cover device according to claim 2, wherein at least a portion of the ceiling surface of the cover facing the gas fuel retention space has an inclined surface that slopes upward from the turbine casing side toward the silencer side.
4. The cover device for a supercharger according to claim 2 or 3, wherein the cover covers from above a portion of the silencer that is 10% or more of the axial length of the compressor.
5. The cover device for a supercharger according to claim 4, wherein the cover covers from above a portion of the silencer that is 10% or more and 50% or less of the axial length of the compressor.
6. The supercharger further includes a rotating shaft that coaxially connects the turbine and the compressor, and a bearing base that houses a bearing that rotatably supports the rotating shaft, wherein the turbine casing is connected to an inlet pipe for introducing the exhaust gas into the turbine casing, an outlet pipe for releasing the exhaust gas out of the turbine casing, and the bearing base, and the portion where the turbine casing and the inlet pipe connect to each other is designated as a first joint, the portion where the turbine casing and the outlet pipe connect to each other is designated as a second joint, and the portion where the turbine casing and the bearing base connect to each other is designated as a third joint, the cover covers at least one of the first joint, the second joint, and the third joint from above, the supercharger cover device according to any one of claims 1 to 3.
7. The supercharger cover device according to claim 1, further comprising a draw-in pipe configured to draw the gas accumulating in the gas fuel retention space towards the silencer side by the negative pressure of the compressor.
8. A method for operating an engine system comprising a supercharger, a supercharger cover device according to any one of claims 1 to 3, and an engine for discharging the exhaust gas flowing into the turbine casing, the method comprising the step of performing a diesel operation in which diesel fuel is burned in the engine when the fuel combustion operation in which the engine burns the fuel stops.
9. The method for operating the engine system according to claim 8, wherein the engine system further comprises a concentration detection device for detecting the concentration of the gas fuel in the gas fuel retention space, and the step of performing diesel operation is to perform diesel operation until the concentration of the gas fuel detected by the concentration detection device falls below a preset threshold.
10. A method for installing a turbocharger cover device used in a turbocharger that can be driven by exhaust gas generated by the combustion of a fuel that is lighter than air in its gaseous state, wherein the turbocharger includes a turbine including a turbine casing into which the exhaust gas flows, a compressor including a compressor casing into which intake air flows, a silencer connected to the compressor casing for reducing noise generated when the intake air is introduced from the surroundings, a rotating shaft coaxially connecting the turbine and the compressor, and a bearing base housing a bearing that rotatably supports the rotating shaft, the method for installing the turbocharger cover device comprising the step of attaching a cover that covers at least a part of the turbine casing from above, and defines a gas fuel retention space between the turbine casing and the cover, in the event of leakage of the gaseous fuel, to the bearing base via a support member, the cover being used in the method for installing the turbocharger cover device.