JP7594042B2 - Compressor housing, compressor and turbocharger - Google Patents

Description

This disclosure relates to a compressor housing that houses a compressor impeller, and a compressor and a turbocharger that include the compressor housing.

When the engine is started, there is little exhaust gas flowing from the engine to the turbocharger, and due to the inertia of the turbocharger's rotor, the turbocharger does little work, and the amount of compressed air sent from the turbocharger to the engine is small, which can result in black smoke being emitted from the engine. In order to reduce this type of black smoke emission and improve the turbocharger's load response (speed-up) at engine start-up and thereby improve turbocharger efficiency, there is a method of injecting compressed gas into the impeller blades of the compressor impeller from injection holes provided in the air guide tube of the compressor casing.

Patent document 1 describes how, when increasing the engine load, a target supercharged air pressure is obtained by supplying compressed air (compressed gas) to the impeller blades of the compressor impeller from a large number of injection holes provided around the entire outer periphery of the compressor impeller in the supercharger.

Japanese Unexamined Patent Publication No. 132721/1986

When compressed gas is injected near the outlet of the compressor impeller (the outer periphery of the compressor impeller) as in the configuration described in Patent Document 1, a large moment is obtained to assist the rotation of the compressor impeller when the engine load is relatively small, such as when the engine is started. Compared to the configuration described in Patent Document 1, there is a demand for further improvement in the load responsiveness (speed increase) of the turbocharger when the engine is started.

In view of the above, at least one embodiment of the present disclosure aims to provide a compressor housing that can effectively support the rotation of a compressor impeller, and a compressor and a turbocharger that include the compressor housing.

A compressor housing according to at least one embodiment of the present disclosure includes:
A compressor housing configured to rotatably accommodate a compressor impeller having a hub and a plurality of vanes provided on an outer surface of the hub,
a shroud portion having a shroud surface that is convexly curved to face the plurality of blades;
At least one injection hole is provided in the shroud portion for injecting water or a mixture of water and air toward the compressor impeller.

In accordance with at least one embodiment of the present disclosure, a compressor includes:
The compressor housing and the compressor impeller are provided.

A turbocharger according to at least one embodiment of the present disclosure includes the compressor.

At least one embodiment of the present disclosure provides a compressor housing that can effectively support the rotation of a compressor impeller, and a compressor and a turbocharger that include the compressor housing.

1 is a schematic configuration diagram illustrating a configuration of an engine system equipped with a turbocharger according to an embodiment of the present disclosure. FIG. FIG. 1 is a schematic cross-sectional view taken along a central axis of a turbocharger according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view taken along a central axis of a compressor side of a turbocharger according to an embodiment of the present disclosure. FIG. 4 is an explanatory diagram for explaining an arrangement of injection holes in one embodiment of the present disclosure.

Below, several embodiments of the present disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present disclosure and are merely illustrative examples.

(Engine System)
1 is a schematic diagram illustrating the configuration of an engine system 1 equipped with a turbocharger 2 according to an embodiment of the present disclosure. The turbocharger 2 according to some embodiments of the present disclosure is installed in the engine system 1 including an engine 11 as shown in FIG.

As shown in FIG. 1, the engine system 1 includes an engine (engine body) 11 configured to generate power by burning fuel inside, a combustion gas supply line 12 for compressing and supplying the combustion gas to be used for combustion inside the engine 11, a supercharger 2 including a compressor (centrifugal compressor) 21 provided on the combustion gas supply line 12, and a cooler (intercooler) 13 provided downstream of the compressor 21 on the combustion gas supply line 12. The compressor 21 is configured to compress and pressurize the combustion gas. The cooler 13 is a heat exchanger configured to cool the combustion gas heated and pressurized by the compressor 21. Examples of fuel for the engine 11 include gas fuels such as liquefied natural gas and liquid fuels such as fuel oil. Examples of the combustion gas for the engine 11 include air.

The engine 11 includes at least one cylinder 111 and at least one piston 112 accommodated in the at least one cylinder 111 so as to be capable of reciprocating along the axial direction of the cylinder 111. The engine 11 has a combustion chamber 113 therein that is partitioned by the cylinder 111 and the piston 112.

The combustion gas supply line 12 includes a flow path 12A for guiding the combustion gas to the compressor 21, a flow path 12B for guiding the combustion gas discharged from the compressor 21 to the cooler 13, and a flow path 12C for guiding the combustion gas discharged from the cooler 13 to the combustion chamber 113. Each of the flow paths 12A, 12B, and 12C is formed, for example, by piping. The combustion chamber 113 is connected to the flow path 12C downstream of the cooler 13 of the combustion gas supply line 12, and the combustion gas flows in from the combustion gas supply line 12.

As shown in FIG. 1, the engine system 1 further includes an exhaust gas line 14 for guiding exhaust gas discharged from the engine 11, and a fuel injection valve 15 configured to inject fuel into the engine 11. The turbocharger 2 described above further includes a turbine 22 provided in the exhaust gas line 14. The exhaust gas line 14 includes a flow path 14A for guiding exhaust gas discharged from the combustion chamber 113 to the turbine 22. The flow path 14A is formed by, for example, piping. The combustion chamber 113 is connected to the flow path 14A of the exhaust gas line 14, and exhausts exhaust gas generated by combustion in the combustion chamber 113 into the exhaust gas line 14.

The fuel injection valve 15 is configured to inject fuel into either the combustion chamber 113 or the flow path 12C formed inside the engine 11. The fuel injected from the fuel injection valve 15 into the combustion chamber 113 or the flow path 12C is mixed with the combustion gas sent to the combustion chamber 113 through the flow path 12C, and then combusts in the combustion chamber 113. The exhaust gas after combustion in the combustion chamber 113 passes through the exhaust gas line 14 and is discharged to the outside of the engine system 1.

(Turbocharger)
2 is a schematic cross-sectional view taken along a central axis CA of a turbocharger 2 according to an embodiment of the present disclosure. As shown in Fig. 1 and Fig. 2, the turbocharger 2 includes the above-mentioned compressor 21 that compresses a combustion gas (e.g., air) to be supplied to the engine 11, the above-mentioned turbine 22 that is driven by the energy of exhaust gas discharged from the engine 11, and a rotating shaft 23.

The compressor 21 includes a compressor impeller 3 provided in the combustion gas supply line 12 described above, and a compressor housing 4 that rotatably houses the compressor impeller 3. The turbine 22 includes a turbine wheel 24 provided in the exhaust gas line 14 described above, and a turbine housing 25 that rotatably houses the turbine wheel 24. The compressor impeller 3 is mechanically connected to one side of the rotating shaft 23, and the turbine wheel 24 is mechanically connected to the other side of the rotating shaft 23.

The combustion gas that has passed through the compressor impeller 3 is led to the combustion chamber 113 of the engine 11 through the combustion gas supply line 12, and is used for combustion in the combustion chamber 113 together with fuel injected from the fuel injection valve 15. The exhaust gas generated by the combustion in the combustion chamber 113 is led to the turbine wheel 24 through the exhaust gas line 14. The supercharger 2 is configured to rotate the turbine wheel 24 by the energy of the exhaust gas discharged from the engine 11. The compressor impeller 3 is mechanically connected to the turbine wheel 24 via the rotating shaft 23, so it rotates in conjunction with the rotation of the turbine wheel 24. The supercharger 2 is configured to compress the combustion gas passing through the compressor impeller 3 by the rotation of the compressor impeller 3, increase the density of the combustion gas, and send it to the engine 11.

As shown in FIG. 2, the turbocharger 2 further includes a bearing 26 that rotatably supports the rotating shaft 23 between the compressor impeller 3 and the turbine wheel 24, and a bearing stand 27 that is disposed between the compressor housing 4 and the turbine housing 25 and supports the bearing 26.

The compressor housing 4 has a gas introduction passage forming section 42 that extends along the axial direction of the rotating shaft 23 and forms a gas introduction passage 41 for guiding the combustion gas to the compressor housing 4, and a scroll passage forming section 44 that is provided on the outer periphery of the compressor impeller 3 and forms a spiral scroll passage 43 that extends along the circumferential direction of the rotating shaft 23. The turbine housing 25 has a scroll passage forming section 252 that is provided on the outer periphery of the turbine wheel 24 and forms a spiral scroll passage 251 that extends along the circumferential direction of the rotating shaft 23, and an exhaust gas exhaust passage forming section 254 that extends along the axial direction of the rotating shaft 23 and forms an exhaust gas exhaust passage 253 for exhausting the exhaust gas that has passed through the turbine wheel 24.

(Compressor)
3 is a schematic cross-sectional view along the central axis CA of the compressor 21 side of the turbocharger 2 according to an embodiment of the present disclosure. As shown in FIG. 3, the compressor impeller 3 has a hub 31 attached to the one side of the rotating shaft 23 and a plurality of blades 33 provided to protrude from an outer surface 32 of the hub 31. Since the hub 31 is mechanically fixed to the one side of the rotating shaft 23, the hub 31 and the plurality of blades 33 can rotate integrally with the rotating shaft 23. The compressor impeller 3 is a centrifugal impeller configured to guide the combustion gas introduced from one side (left side in FIG. 3) in the axial direction in which the central axis CA of the compressor impeller 3 (turbocharger 2) extends to the outside in the radial direction of the turbocharger 2. In the illustrated embodiment, the outer surface 32 of the hub 31 is formed in a concave curved shape in which the distance from the central axis CA of the turbocharger 2 (rotating shaft 23) increases as the axial direction of the turbocharger 2 moves from the one side to the other side (right side in FIG. 3).

As shown in FIG. 3, the compressor housing 4 further has a shroud portion (air guide tube) 46 having a shroud surface 45 that is convexly curved to face the plurality of blades 33 with a gap therebetween. Each of the plurality of blades 33 has a tip side edge 34 that extends from the outer circumferential end of the leading edge 331 of the blade 33 to the outer circumferential end of the trailing edge and faces the shroud surface 45 with a gap therebetween. Each of the shroud surface 45 and the tip side edge 34 is formed in a curved shape such that the distance from the central axis CA of the turbocharger 2 increases from the one side toward the other side in the axial direction of the turbocharger 2.

In the illustrated embodiment, the shroud portion 46 is configured in a cylindrical shape to surround the compressor impeller 3. The inner and outer diameters of the shroud portion 46 expand toward the other side in the axial direction of the turbocharger 2 from the leading edge 331 of the compressor impeller 3.

As shown in FIG. 3, the compressor housing 4 is provided in the shroud portion 46 and has at least one injection hole 5 for injecting water W or a mixed fluid MF of water and air toward the compressor impeller 3. Each of the at least one injection hole 5 is configured to inject water W or a mixed fluid MF of water and air toward the negative pressure surface (blade surface) 330 of the blade 33 of the compressor impeller 3. The negative pressure surface 330 is located on an extension line of the central axis LA of each of the at least one injection hole 5. The water W or mixed fluid MF injected from the at least one injection hole 5 collides with the negative pressure surface 330, thereby supporting the rotation of the compressor impeller 3.

In the illustrated embodiment, a cylindrical nozzle 50 is fitted into a through hole 461 that penetrates from the outer peripheral surface of the shroud portion 46 to the inner peripheral surface (shroud surface 45). The above-mentioned injection hole 5 is formed on the inner surface of the cylindrical nozzle 50. In the embodiment shown in FIG. 3, the through hole 461 penetrates the shroud portion 46 in a straight line. The injection hole 5 is connected to a space formed inside the compressor housing 4 that houses the compressor impeller 3.

In the illustrated embodiment, an annular space 47 is formed between the outer peripheral surface of the shroud portion 46 and the scroll flow passage forming portion 44, and a fluid introduction line 51 passes through the annular space 47. The end of the nozzle 50 away from the space housing the compressor impeller 3 is connected to one end of a fluid introduction line 51 for guiding the water W or mixed fluid MF to be injected to the injection hole 5, and the water W or mixed fluid MF is guided from the fluid introduction line 51 to the injection hole 5. Note that the fluid introduction line 51 is not limited to the configuration described above or below as long as it is capable of guiding the water W or mixed fluid MF to the injection hole 5.

According to the above configuration, water is an incompressible fluid and does not cause choked flow, so there is no need to restrict the flow rate to prevent the choked flow. Therefore, the flow rate of the water W or mixed fluid MF injected from the at least one injection hole 5 can be increased compared to when air is injected. By injecting the water W or mixed fluid MF toward the compressor impeller 3, the rotation of the compressor impeller 3 can be supported more effectively than when air is injected, and thus the rotation of the compressor impeller 3 can be improved to follow the rotation of the engine 11.

In addition, with the above configuration, the water injected from at least one of the injection holes 5 can cool the combustion gas, which is the intake air passing through the compressor impeller 3, thereby improving the efficiency of the compressor 21 and the engine system 1 equipped with the compressor 21.

The present disclosure is applicable to both cases where the engine 11 runs on liquid fuel and cases where it runs on gas fuel, but is particularly suitable for cases where the engine 11 runs on gas fuel, which has a relatively large load fluctuation. Examples of engines 11 that run on gas fuel include main engines for ships and power generation engines installed on land.

In some embodiments, as shown in FIG. 3, each of the above-mentioned multiple injection holes 5 is configured to inject the mixed fluid MF or water W to the outer periphery side of the compressor impeller 3. In the embodiment shown in FIG. 3, the position of the central axis CA of the compressor impeller 3 is defined as 0% in the radial position of the compressor impeller 3, and the position 35 of the maximum outer diameter of the hub 31 is defined as 100%. Each of the above-mentioned multiple injection holes 5 is configured so that a straight line extending from the central axis LA intersects with the negative pressure surface (blade surface) 330 on the outer periphery side of the compressor impeller 3, that is, at a radial position of 50% to 100% of the compressor impeller 3. It is preferable that the straight line extending from the central axis LA intersects with the negative pressure surface 330 at a radial position of 60% to 100% of the compressor impeller 3.

According to the above configuration, by injecting the mixed fluid MF or water W onto the outer periphery of the compressor impeller 3, the torque acting on the compressor impeller 3 due to the collision of the mixed fluid MF or water W can be increased compared to when the mixed fluid MF or water W is injected onto the inner periphery of the compressor impeller 3, and the rotation of the compressor impeller 3 can be effectively supported.

Fig. 4 is an explanatory diagram for explaining the arrangement of the injection holes 5 in one embodiment of the present disclosure. Fig. 4 shows a schematic view of the compressor impeller 3 as viewed from one side in the axial direction. The symbol R in Fig. 4 indicates the rotation direction of the compressor impeller 3.
4, each of the above-mentioned multiple injection holes 5 is configured to inject the mixed fluid MF or water W along a tangential direction T with respect to the rotation direction R of the compressor impeller 3. Each of the multiple injection holes 5 injects the mixed fluid MF or water W along a direction toward the downstream side of the rotation direction R of the compressor impeller 3, among the tangential directions T with respect to the rotation direction R of the compressor impeller 3.

According to the above configuration, by injecting the mixed fluid MF or water W along the tangential direction T relative to the rotation direction R of the compressor impeller 3, the collision force of the mixed fluid MF or water W acts effectively on the compressor impeller 3, thereby effectively supporting the rotation of the compressor impeller 3.

In some embodiments, the above-mentioned multiple injection holes 5 include at least one water injection hole 6 configured to inject only water W, of the water W or the mixed fluid MF, into the compressor impeller 3, as shown in Figures 1 and 4. In some embodiments, all of the multiple injection holes 5 may be water injection holes 6.

According to the above configuration, the water W is an incompressible fluid and does not cause choked flow, so there is no need to restrict the flow rate to prevent the choked flow. By injecting the water W toward the compressor impeller 3, the rotation of the compressor impeller 3 can be more effectively supported than when the mixed fluid MF is injected.

In some embodiments, the above-mentioned multiple injection holes 5 include at least one mixed fluid injection hole 7 configured to inject only the mixed fluid MF, of the water W or the mixed fluid MF, into the compressor impeller 3, as shown in Figures 1 and 4. In some embodiments, all of the multiple injection holes 5 may be mixed fluid injection holes 7.

According to the above configuration, by injecting the mixed fluid MF toward the compressor impeller 3, the water W contained in the mixed fluid MF can be diffused over a relatively wide area, so that the supply air passing through the compressor impeller 3 can be effectively cooled. In addition, when the mixed fluid MF is injected toward the compressor impeller 3, the amount of drainage can be reduced compared to when water W is injected.

In some embodiments, the at least one injection hole 5 described above includes a plurality of injection holes 5 spaced apart in the circumferential direction of the compressor impeller 3, as shown in Figs. 1 and 4. The plurality of injection holes 5 includes at least one water injection hole 6 configured to inject only the water W of the water W or the mixed fluid MF into the compressor impeller 3, and at least one mixed fluid injection hole 7 configured to inject only the mixed fluid MF of the water W or the mixed fluid MF into the compressor impeller 3.

According to the above configuration, the rotation of the compressor impeller 3 can be effectively supported by injecting water W from the water injection holes 6 toward the compressor impeller 3. In addition, the supply air passing through the compressor impeller 3 can be effectively cooled by injecting the mixed fluid MF toward the compressor impeller 3 from the mixed fluid injection holes 7.

In some embodiments, as shown in FIG. 4, the at least one water injection hole 6 includes a first water injection hole 6A and a second water injection hole 6B arranged at a circumferentially opposite position to the first water injection hole 6A across the central axis CA of the compressor impeller 3. The at least one mixed fluid injection hole 7 includes a first mixed fluid injection hole 7A arranged between the first water injection hole 6A and the second water injection hole 6B in the circumferential direction of the compressor impeller 3, and a second mixed fluid injection hole 7B arranged at a circumferentially opposite position to the first mixed fluid injection hole 7A across the central axis CA of the compressor impeller 3. In the embodiment shown in FIG. 4, the compressor housing 4 includes two water injection holes 6A, 6B and two mixed fluid injection holes 7A, 7B, but the number of water injection holes 6 and mixed fluid injection holes 7 provided in the compressor housing 4 is not limited to this.

As shown in FIG. 4, when viewed from one side in the axial direction of the compressor impeller 3, if the circumferential position of the central axis LA of a certain injection hole 5 is defined as 0°, being located at opposing circumferential positions across the central axis CA means being located within a circumferential range of 90° to 270°.

In the embodiment shown in FIG. 4, when viewed from one side in the axial direction of the compressor impeller 3, the circumferential position of the central axis LA of the first water injection hole 6A is defined as 0°, and the circumferential angle θ is defined with the rotation direction R of the compressor impeller 3 as the positive direction. The second water injection hole 6B is arranged within a circumferential range of 90° to 270°. The second water injection hole 6B is preferably arranged within a circumferential range of 120° to 240°, and more preferably within a circumferential range of 150° to 210°.

The first mixed fluid injection hole 7A is preferably arranged within a circumferential range of 30° to 150°, and more preferably within a circumferential range of 60° to 120°. The second mixed fluid injection hole 7B is preferably arranged within a circumferential range of 210° to 330°, and more preferably within a circumferential range of 240° to 300°.

According to the above configuration, by arranging the water injection holes 6A, 6B and the mixed fluid injection holes 7A, 7B relatively evenly in the circumferential direction, it is possible to prevent the collision force of the mixed fluid or water from acting unevenly on a part of the circumferential direction of the compressor impeller 3, and the rotation of the compressor impeller 3 can be effectively supported by the collision force.

(Water and mixed fluid supply systems)
1, the other end of the fluid introduction line 51 is connected to a water storage tank 52 as a supply source of water W. The water storage tank 52 is configured to store water at room temperature (0°C to 40°C), for example. The fluid introduction line 51 is provided with a pump 53 for pressurizing the water W flowing through the fluid introduction line 51. The water W injected from the injection hole 5 is pressurized by the pump 53. The fluid introduction line 51 may be provided with a valve for controlling the supply of water W from the water storage tank 52.

The fluid introduction line 51 branches into multiple lines 51A, 51B at a branching point P1 located on the other end side of the pump 53. Of the multiple branching lines 51A, 51B, the line connected to the water injection hole 6 is the water introduction line 51A, and the line connected to the mixed fluid injection hole 7 is the mixed fluid introduction line 51B. The mixed fluid introduction line 51B is adapted to merge with the compressed air introduction line 54, through which compressed air A flows, at a merging point P2.

Water W is introduced into the water injection hole 6 via the pump 53 side of the branching point P1 of the fluid introduction line 51 and the water introduction line 51A. A mixed fluid MF, which is a mixture of water W and compressed air A, is introduced into the mixed fluid injection hole 7 via the pump 53 side of the branching point P1 of the fluid introduction line 51, the mixed fluid introduction line 51B, and the compressed air introduction line 54.

The compressed air introduction line 54 may be connected to the flow path 12C on the upstream side, and a portion of the air flowing through the flow path 12C may be drawn off to the compressed air introduction line 54. In this case, the air flowing through the flow path 12C is pressurized by the compressor 21, so that a pump for sending the compressed air A to the mixed fluid injection hole 7 is not required. The water storage tank 52 may be configured to store engine cooling water for cooling the engine 11, and the fluid introduction line 51 may share a line from the water storage tank 52 to the branch point P3 with the cooling water introduction line 55 for leading the engine cooling water from the water storage tank 52 to the engine 11.

(Drain water discharge system)
The cooler 13 is equipped with a mechanism for discharging drain water generated by condensation of the combustion gas, and when the water W ejected from the injection hole 5 flows downstream of the compressor impeller 3 (towards the engine 11), it is recovered in the cooler 13.

As shown in FIG. 3, the compressor housing 4 may have a recess 48 formed vertically downward on the vertical lower side of the shroud portion 46, capable of storing water W. The recess 48 may have a water discharge hole 49 formed therein, extending vertically downward from the recess 48 to the outer surface of the compressor housing 4. The water W ejected from the injection hole 5 falls from the compressor impeller 3 and accumulates in the recess 48. The water W accumulated in the recess 48 is discharged to the outside of the compressor housing 4 via the water discharge hole 49.

As shown in FIG. 1, the turbocharger 2 according to some embodiments includes a compressor 21 having the compressor impeller 3 and compressor housing 4 described above.

According to the above configuration, by injecting water W or mixed fluid MF toward the compressor impeller 3, the rotation of the compressor impeller 3 can be effectively supported, thereby improving the efficiency of the compressor 21. In addition, the water W injected toward the compressor impeller 3 can cool the supply air passing through the compressor impeller 3, thereby improving the efficiency of the compressor 21. By improving the efficiency of the compressor 21, the efficiency of the turbocharger 2 can be improved.

In this specification, expressions expressing relative or absolute configuration, such as "in a certain direction,""along a certain direction,""parallel,""orthogonal,""center,""concentric," or "coaxial," do not only strictly express such a configuration, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained.
For example, expressions indicating that things are in an equal state, such as "identical,""equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained.
Furthermore, in this specification, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained.
In addition, in this specification, the expressions "comprise,""include," or "have" a certain element are not exclusive expressions that exclude the presence of other elements.

The present disclosure is not limited to the above-described embodiments, but also includes variations of the above-described embodiments and appropriate combinations of these embodiments.

The contents described in the above-mentioned embodiments can be understood, for example, as follows:

1) A compressor housing (4) according to at least one embodiment of the present disclosure comprises:
A compressor housing (4) configured to rotatably accommodate a compressor impeller (3) having a hub (31) and a plurality of vanes (33) provided on an outer surface (32) of the hub (31),
a shroud portion (46) having a shroud surface (45) curved convexly to face the plurality of blades (4);
and at least one injection hole (5) provided in the shroud portion (46) for injecting water or a mixture of water and air toward the compressor impeller (3).

According to the configuration of 1) above, since water has a higher density than air, the energy required to rotate the compressor impeller (3) is less than that of air. In addition, since water is an incompressible fluid and does not cause choked flow, there is no need to restrict the flow rate to prevent the choked flow. Therefore, the flow rate of the water or mixed fluid injected from the at least one injection hole (5) can be increased compared to the case where air is injected. By injecting water or mixed fluid toward the compressor impeller (3), the rotation of the compressor impeller (3) can be more effectively supported than when air is injected, and thus the rotation of the compressor impeller (3) can be improved to follow the rotation of the engine (11).

In addition, according to the configuration of 1) above, the water injected from the at least one injection hole (5) can cool the intake air passing through the compressor impeller (3), thereby improving the efficiency of the compressor (21) and the engine system (1) equipped with the compressor (21).

2) In some embodiments, the compressor housing (4) according to 1) above,
The at least one injection hole (5) is configured to inject the mixed fluid or the water onto the outer circumferential side of the compressor impeller (3).

According to the configuration of 2) above, by injecting the mixed fluid or water onto the outer periphery of the compressor impeller (3), the torque acting on the compressor impeller (3) due to the collision of the mixed fluid or water can be increased compared to when the mixed fluid or water is injected onto the inner periphery of the compressor impeller (3), and the rotation of the compressor impeller (3) can be effectively supported.

3) In some embodiments, the compressor housing (4) according to 1) or 2) above,
The at least one injection hole (5) is configured to inject the mixed fluid or the water along a tangential direction (T) relative to a rotation direction (R) of the compressor impeller (3).

According to the configuration of 3) above, by injecting the mixed fluid or water along the tangential direction (T) relative to the rotation direction (R) of the compressor impeller (3), the collision force of the mixed fluid or water acts effectively on the compressor impeller (3), thereby effectively supporting the rotation of the compressor impeller (3).

4) In some embodiments, the compressor housing (4) according to any one of 1) to 3) above,
The at least one injection hole (5) includes at least one water injection hole (6) configured to inject only the water of the water or the mixed fluid into the compressor impeller (3).

According to the configuration of 4) above, since water has a higher density than the mixed fluid, less energy is required to rotate the compressor impeller (3). By injecting water toward the compressor impeller (3), the rotation of the compressor impeller (3) can be more effectively supported than in the case of injecting a mixed fluid.

5) In some embodiments, the compressor housing (4) according to any one of 1) to 3) above,
The at least one injection hole (5) includes at least one mixed fluid injection hole (7) configured to inject only the mixed fluid, of the water or the mixed fluid, into the compressor impeller (3).

According to the configuration of 5) above, by injecting the mixed fluid toward the compressor impeller (3), the water contained in the mixed fluid can be dispersed over a relatively wide area, so that the supply air passing through the compressor impeller (3) can be effectively cooled. In addition, when the mixed fluid is injected toward the compressor impeller (3), the amount of drainage can be reduced compared to when water is injected.

6) In some embodiments, the compressor housing (4) according to any one of 1) to 3) above,
The at least one injection hole (5) includes a plurality of injection holes (5) spaced apart in a circumferential direction of the compressor impeller (3),
The plurality of injection holes (5)
At least one water injection hole (6) configured to inject only the water of the water or the mixed fluid into the compressor impeller (3);
and at least one mixed fluid injection hole (7) configured to inject only the mixed fluid, out of the water or the mixed fluid, into the compressor impeller (3).

According to the configuration of 6) above, the rotation of the compressor impeller (3) can be effectively assisted by injecting water from the water injection holes (6) toward the compressor impeller (3). In addition, the supply air passing through the compressor impeller (3) can be effectively cooled by injecting the mixed fluid from the mixed fluid injection holes (7) toward the compressor impeller (3).

7) In some embodiments, the compressor housing (4) according to 6) above,
The at least one water injection hole (6)
A first water injection hole (6A);
and a second water injection hole (6B) arranged at a position opposite to the first water injection hole (6A) in the circumferential direction across a central axis (CA) of the compressor impeller (3),
The at least one mixed fluid injection hole (7) is
a first mixed fluid injection hole (7A) arranged between the first water injection hole (6A) and the second water injection hole (6B) in the circumferential direction;
and a second mixed fluid injection hole (7B) arranged at a position opposite to the first mixed fluid injection hole (7A) in the circumferential direction across the central axis (CA) of the compressor impeller (3).

According to the configuration of 7) above, by arranging the water injection holes (6A, 6B) and the mixed fluid injection holes (7A, 7B) relatively evenly in the circumferential direction, it is possible to prevent the collision force of the mixed fluid or water from acting unevenly on a part of the circumferential direction of the compressor impeller (3), and the rotation of the compressor impeller (3) can be effectively supported by the collision force.

8) The compressor (21) according to at least one embodiment of the present disclosure comprises:
A compressor housing (4) according to any one of 1) to 7) above;
The compressor impeller (3).

According to the configuration of 8) above, the rotation of the compressor impeller (3) can be effectively assisted by injecting water or a mixed fluid toward the compressor impeller (3), thereby improving the efficiency of the compressor (21). In addition, the water injected toward the compressor impeller (3) can cool the supply air passing through the compressor impeller (3), thereby improving the efficiency of the compressor (21).

9) The turbocharger (2) according to at least one embodiment of the present disclosure is
The compressor (21) described in 8) above is provided.

According to the configuration of 9) above, the efficiency of the compressor (21) can be improved, thereby improving the efficiency of the turbocharger (2).

1 Engine system 2 Turbocharger 3 Compressor impeller 4 Compressor housing 5 Injection holes 6, 6A, 6B Water injection holes 7, 7A, 7B Mixed fluid injection holes 11 Engine 12 Combustion gas supply line 13 Cooler 14 Exhaust gas line 15 Fuel injection valve 21 Compressor 22 Turbine 23 Rotating shaft 24 Turbine wheel 25 Turbine housing 26 Bearing 27 Bearing stand 31 Hub 32 Outer surface 33 Blade 34 Tip side edge 45 Shroud surface 46 Shroud portion 50 Nozzle 51 Fluid introduction line 51A Water introduction line 51B Mixed fluid introduction line 52 Water storage tank 53 Pump 54 Compressed air introduction line 55 Cooling water introduction line A Compressed air CA Central axis LA Central axis MF Mixed fluid R Rotation direction W Water

Claims (10)

A compressor housing configured to rotatably accommodate a compressor impeller having a hub and a plurality of vanes provided on an outer surface of the hub,
a shroud portion having a shroud surface that is convexly curved to face the plurality of blades;
At least one injection hole provided in the shroud portion for injecting water or a mixed fluid of water and air toward an outer circumferential side of the compressor impeller,
In the radial position of the compressor impeller, when the position of the central axis of the compressor impeller is defined as 0% and the position of the maximum outer diameter of the hub is defined as 100%,
The at least one injection hole is configured so that an extension line of a central axis of the at least one injection hole intersects with a suction surface of the blade of the compressor impeller at a radial position of 50% or more and 100% or less of the compressor impeller.
Compressor housing. The at least one injection hole is configured to inject the mixed fluid or the water along a tangential direction to a rotation direction of the compressor impeller.
The compressor housing of claim 1 . The at least one injection hole includes at least one water injection hole configured to inject only the water of the water or the mixed fluid into the compressor impeller.
A compressor housing according to claim 1 or 2 . The at least one injection hole includes at least one mixed fluid injection hole configured to inject only the mixed fluid, of the water or the mixed fluid, into the compressor impeller.
A compressor housing according to claim 1 or 2 . A recess is provided on a lower side of the shroud portion in the vertical direction, the recess being recessed vertically downward,
A water drain hole is formed in the recess, the water drain hole extending from the recess toward the downward side in the vertical direction to an outer surface of the compressor housing.
A compressor housing according to claim 1 or 2 . A compressor housing configured to rotatably accommodate a compressor impeller having a hub and a plurality of vanes provided on an outer surface of the hub,
a shroud portion having a shroud surface that is convexly curved to face the plurality of blades;
At least one injection hole provided in the shroud portion for injecting water or a mixture of water and air toward the compressor impeller,
The at least one injection hole includes a plurality of injection holes spaced apart in a circumferential direction of the compressor impeller,
The plurality of injection holes include
At least one water injection hole configured to inject only the water of the water or the mixed fluid into the compressor impeller;
At least one mixed fluid injection hole configured to inject only the mixed fluid of the water or the mixed fluid onto the compressor impeller.
Compressor housing. The at least one water injection hole is
A first water injection hole;
a second water injection hole arranged at a position opposite to the first water injection hole in the circumferential direction across a central axis of the compressor impeller,
The at least one mixed fluid injection hole is
a first mixed fluid injection hole disposed between the first water injection hole and the second water injection hole in the circumferential direction;
a second mixed fluid injection hole disposed at a position facing the first mixed fluid injection hole in the circumferential direction across the central axis of the compressor impeller,
The compressor housing of claim 6 . A compressor housing configured to rotatably accommodate a compressor impeller having a hub and a plurality of vanes provided on an outer surface of the hub,
a shroud portion having a shroud surface that is convexly curved to face the plurality of blades;
at least one injection hole provided in the shroud portion for injecting water or a mixed fluid of water and air toward the compressor impeller, and supporting rotation of the compressor impeller by causing the injected water or the mixed fluid to collide with a negative pressure surface of the blade;
A recess is provided on a lower side of the shroud portion in the vertical direction, the recess being recessed vertically downward,
A water drain hole is formed in the recess, the water drain hole extending from the recess toward the downward side in the vertical direction to an outer surface of the compressor housing .
Compressor housing. A compressor housing according to any one of claims 1 , 2, 6, 7 and 8 ;
The compressor impeller,
Compressor. A turbocharger comprising the compressor according to claim 9 .

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