Power generation turbine

Abstract

To provide a power generation turbine capable of cooling a power generator while suppressing an increase in complexity and size of the structure.SOLUTION: A power generation turbine comprises: a rotating shaft; a power generator that includes a rotor provided on one side of the rotating shaft and a stator disposed on an inner peripheral side of the rotor; a turbine rotor blade provided closer to the other side of the rotating shaft than the power generator; an inner casing that has an opposing surface opposing a disk portion of the turbine rotor blade with a gap therebetween, and that forms a power generator housing space which communicates with the gap and houses the power generator; and an outer casing that is disposed on an outer peripheral side of the inner casing and that forms, between the outer casing and the inner casing, a working fluid flow path which communicates with the gap and through which working fluid of the turbine rotor blade flows. The inner casing is formed with a through-hole having an outer opening that is formed on an outer surface forming the working fluid flow path, and an inner opening that is formed on an inner surface forming the power generator housing space.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to turbines for power generation. [Background technology]

[0002] Liquefied gas (for example, liquefied natural gas) is liquefied for the purpose of transportation and storage, and when it is supplied to a destination such as city gas or thermal power generation, it is heated and vaporized using a heat medium such as seawater. When vaporizing liquefied gas, there is a type of cold energy power generation in which the cold energy is recovered as electricity rather than being dumped into seawater.

[0003] ORC (Organic Rankine Cycle) is a known cold energy power generation cycle that uses liquefied natural gas. ORC is a cycle process in which a low-temperature working fluid with a boiling point lower than that of water circulating in a closed loop is cooled and condensed with liquefied natural gas in a condenser, then pressurized by a pump, heated and evaporated in an evaporator using seawater or other heat sources, and the resulting steam is introduced into a cold energy power generation turbine to generate power.

[0004] Patent Document 1 discloses a cold energy power generation turbine in which two radial turbines and generators are arranged coaxially in the same casing in order to reduce the size of the cold energy power generation device. In this cold energy power generation turbine, the generator is arranged in the center of the shaft, and radial turbines are arranged on both ends of the shaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-218816 Summary of the Invention [Problem to be solved by the invention]

[0006] Since generators rotate at high speeds, they require cooling, and water cooling is the most common cooling method. With the technology disclosed in Patent Document 1, it is necessary to secure a cooling source (cooling water) to cool the generator, and it is necessary to provide a cooling mechanism such as equipment required for cooling and a cooling flow path. For this reason, there is a concern that the cold energy power generation device will become complicated and large in size.

[0007] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to provide a power-generating turbine capable of cooling a generator while suppressing an increase in the complexity and size of the structure. [Means for solving the problem]

[0008] In accordance with at least one embodiment of the present disclosure, a power generating turbine includes: A rotating shaft; a generator including a rotor provided on one side of the rotating shaft in an axial direction and a stator disposed on an inner peripheral side of the rotor; at least one turbine blade provided on the other side of the rotating shaft in the axial direction relative to the generator; an inner casing configured to rotatably accommodate the rotating shaft, the inner casing having an opposing surface that faces a disk portion of the at least one turbine blade with a first gap therebetween, and forming a generator accommodating space that communicates with the first gap and accommodates the generator; an outer casing disposed on an outer circumferential side of the inner casing, communicating with the first gap between the outer casing and the inner casing to form a working fluid flow passage through which a working fluid of the turbine rotor blade flows; The inner casing is formed with at least one through hole having an outer opening formed on an outer surface that defines the working fluid flow path and an inner opening formed on an inner surface that defines the generator accommodating space. Effect of the Invention

[0009] According to at least one embodiment of the present disclosure, a power generation turbine capable of cooling a generator while suppressing an increase in complexity and size of the structure is provided. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. [Diagram 2] 1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. [Diagram 3] 1 is a schematic cross-sectional view, perpendicular to the axial direction, of a power generating turbine according to an embodiment of the present disclosure; FIG. [Figure 4] 1 is a schematic cross-sectional view along an axial direction near a turbine rotor blade of a power generating turbine according to an embodiment of the present disclosure; FIG. [Diagram 5] 1 is a schematic cross-sectional view along an axial direction near a turbine rotor blade of a power generating turbine according to an embodiment of the present disclosure; FIG. [Figure 6] 1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. [Figure 7] 1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. [Figure 8] 1 is a schematic cross-sectional view along the axial direction of a generator housing space and a bearing housing space of a power generating turbine according to an embodiment of the present disclosure. FIG. [Figure 9] FIG. 1 is a schematic diagram of a power generation system including a power generating turbine according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.

[0012] (Power generation turbines) 1 and 2 are schematic cross-sectional views along the axial direction of a power generation turbine 1 according to an embodiment of the present disclosure. Hereinafter, the direction in which the central axis CA of a rotating shaft 2 of the power generation turbine 1 extends is defined as the axial direction of the rotating shaft 2, the direction perpendicular to the central axis CA is defined as the radial direction of the rotating shaft 2, and the circumferential direction around the central axis CA is defined as the circumferential direction of the rotating shaft 2. In this disclosure, the axial direction, radial direction, and circumferential direction of the rotating shaft 2 may be simply referred to as the axial direction, radial direction, and circumferential direction, respectively. Note that "along a certain direction" in this disclosure includes not only a certain direction, but also a direction inclined within a range of ±15° relative to the certain direction.

[0013] 1 and 2, a power-generating turbine 1 according to some embodiments includes the above-mentioned rotating shaft 2, a generator 3 including a rotor 31 provided on one axial side (left side in the figures) of the rotating shaft 2 and a stator 32 provided on the inner peripheral side (radially inward) of the rotor 31, and at least one turbine blade 4 provided on the other axial side (right side in the figures) of the generator 3. In the present disclosure, the one axial side and the other axial side of the rotating shaft 2 may be simply referred to as the one side and the other side, respectively.

[0014] (Generator) The rotor 31 includes a magnet support part 311 supported in a cantilever manner on the one end part 21 of the rotating shaft 2, and a permanent magnet 312 supported from the outer circumferential side (radially outward) by the magnet support part 311. The stator 32 has a stationary coil part 321 arranged to face the inner circumferential side of the permanent magnet 312 with an inner circumferential gap S21 therebetween.

[0015] In the illustrated embodiment, the magnet support portion 311 includes a disk-shaped radially extending portion 313 whose inner end is mechanically connected to the one end 21 of the rotating shaft 2 by fitting or the like and extending along the radial direction, and a cylindrical axially extending portion 314 that extends along the axial direction from the outer end of the radially extending portion 313 toward the one side in the axial direction. The radially extending portion 313 may at least partially include an inclined portion 315 that is inclined so as to shift toward the one side in the axial direction as it moves radially outward.

[0016] The permanent magnet 312 is supported on the inner peripheral side of the axially extending portion 314. The stator 32 is disposed on the one axial side of the one end portion 21 of the rotating shaft 2, and is provided immovable relative to the rotation of the rotating shaft 2. The inner casing 5 includes a stator support portion 51 that supports the stator 32 from the inner peripheral side.

[0017] (Turbine blades) In the illustrated embodiment, the at least one turbine rotor blade 4 includes a first rotor blade 41 and a second rotor blade 42 provided on the other axial side of the rotating shaft 2 relative to the first rotor blade 41. The first rotor blade 41 and the second rotor blade 42, which are supported on the other side of the rotating shaft 2, have a short inter-blade distance, so that the pressure loss occurring between the rotor blades can be reduced, thereby improving the performance of the power generation turbine 1.

[0018] Each of the one-side rotor blade 41 and the other-side rotor blade 42 has an inner circumferential end attached to the other end of the rotating shaft 2 in the axial direction, and includes a disk portion 43, 45 that protrudes radially outward in a circular plate shape, and a wing portion 44, 46 provided on the outer periphery of the disk portion 43, 45.

[0019] (inner casing) 1 to 3, the power-generating turbine 1 further includes an inner casing 5 configured to rotatably house the rotating shaft 2, and an outer casing 6 arranged on the outer circumferential side (radially outward) of the inner casing 5. The inner casing 5 has an opposing surface 52 that faces the disk portion 43 of the one rotor blade 41 with a first gap S1 therebetween. The inner casing 5 forms a generator housing space S2 therein that houses the generator 3.

[0020] In the illustrated embodiment, the inner casing 5 is provided on one side of the rotating shaft 2 in the axial direction relative to the one-side rotor blade 41, and the opposing surface 52 is the end face of the inner casing 5 on the other side in the axial direction.

[0021] (Bearings) As shown in Figs. 1 to 3, the power-generating turbine 1 further includes at least one bearing 7 (in the illustrated example, a plurality of bearings) that are disposed between the generator 3 and the one rotor blade 41 in the axial direction of the rotating shaft 2 and rotatably support the rotating shaft 2. Each of the plurality of bearings 7 is made of a magnetic bearing that does not require lubricating oil, and is supported by the inner casing 5. The inner casing 5 defines therein a bearing accommodating space S3 that accommodates the rotating shaft 2 and the plurality of bearings 7, between the generator 3 and the one rotor blade 41 in the axial direction of the rotating shaft 2. The bearing accommodating space S3 is connected to the first gap S1 and the generator accommodating space S2, and communicates with the first gap S1 and the generator accommodating space S2.

[0022] In the illustrated embodiment, the rotating shaft 2 has a thrust disk portion 22 that protrudes radially outward in the bearing accommodating space S3 of the rotating shaft 2. The multiple bearings 7 include a one-side thrust bearing 71 that is arranged on one axial side of the rotating shaft 2 relative to the thrust disk portion 22 and faces the thrust disk portion 22 with a gap therebetween, and a second-side thrust bearing 72 that is arranged on the other axial side of the rotating shaft 2 relative to the thrust disk portion 22 and faces the thrust disk portion 22 with a gap therebetween.

[0023] In the illustrated embodiment, the multiple bearings 7 further include a one-side journal bearing 73 arranged between the generator 3 and the one-side thrust bearing 71 in the axial direction of the rotating shaft 2, and an other-side journal bearing 74 arranged between the other-side thrust bearing 72 and the one-side rotor blade 41 in the axial direction of the rotating shaft 2.

[0024] (Outer casing) 1 to 3, the outer casing 6 is disposed on the outer periphery (radially outside) of the inner casing 5, and forms a working fluid flow path S4 between the outer casing 6 and the inner casing 5, through which the working fluid of the turbine rotor blades 4 flows. The working fluid flow path S4 is formed by an inner circumferential surface 61 of the outer casing 6 and an outer circumferential surface 53 of the inner casing 5. The working fluid flowing through the working fluid flow path S4 is in a gaseous state.

[0025] In the illustrated embodiment, the working fluid passage S4 includes an annular passage S41 that is annularly shaped and surrounds the outer periphery of the generator accommodation space S2 and the bearing accommodation space S3, a columnar one-side columnar passage S42 that is formed on the one side in the axial direction from the annular passage S41 and extends along the axial direction, and a columnar other-side columnar passage S43 that is formed on the other side in the axial direction from the annular passage S41 and extends along the axial direction. Each of the one-side columnar passage S42 and the other-side columnar passage S43 is connected to the annular passage S41 and communicates with the annular passage S41.

[0026] (Casing support part) FIG. 3 is a schematic cross-sectional view perpendicular to the axial direction of the power generation turbine 1 according to an embodiment of the present disclosure. In FIG. 3, the inside of the generator housing space S2 is omitted. In the embodiment shown in FIGS. 1 to 3, the power generation turbine 1 includes at least one casing support part 11 that extends through the annular flow passage S41 along the radial direction of the rotating shaft 2. One end of the casing support part 11 is connected to the inner circumferential surface 61 of the outer casing 6, and the other end is connected to the outer circumferential surface 53 of the inner casing 5. The inner casing 5 is supported by the outer casing 6 by the casing support part 11. The first gap S1 is connected to the working fluid flow passage S4 between one end of the one-side rotor blade 41 and the other end of the casing support part 11, and communicates with the working fluid flow passage S4.

[0027] The casing support part 11 is disposed so as to overlap at least a portion with the generator accommodating space S2 in the axial direction, and is connected to the outer peripheral surface 53 of the inner casing 5, so that it also functions as a cooling fin for promoting cooling of the generator 3. It is sufficient that at least one casing support part 11 is disposed along the axial direction, and it is sufficient that at least one is also disposed in the circumferential direction.

[0028] According to the above configuration, by making the generator 3 provided on the other side of the rotating shaft 2 an outer rotor type, it is possible to achieve a higher power density and reduce the radial size of the generator 3 and the generator accommodating space S2 compared to when it is an inner rotor type. As a result, the working fluid flow path S4 formed on the outer periphery of the generator accommodating space S2 can be disposed relatively inward in the radial direction, which makes it possible to prevent the power generation turbine 1 from becoming large.

[0029] (Through hole) 1 and 2, the above-mentioned inner casing 5 has at least one (in the illustrated example, a plurality of) through holes 54 formed therein, the through holes 54 having an outer opening 541 formed in an outer surface 55 that forms the working fluid flow path S4 and an inner opening 542 formed in an inner surface 56 that forms the generator accommodating space S2. The plurality of through holes 54 are disposed at intervals from one another in the circumferential direction of the rotating shaft 2.

[0030] The shape of each of the plurality of through holes 54 is not limited to the illustrated embodiment, and may be any shape that allows the working fluid to flow between the generator accommodating space S2 and the outside of the inner casing 5. In the illustrated embodiment, each of the plurality of through holes 54 is formed in a straight line from the outer opening 541 to the inner opening 542, but is not limited to this shape. In the illustrated embodiment, the outer opening 541 is formed on the end face on the one side in the axial direction of the inner casing 5, but in other embodiments, it may be formed on the outer peripheral surface 53. In the illustrated embodiment, the inner opening 542 is formed on the end face on the other side in the axial direction of the stator support part 51 extending along the axial direction, but it may be formed on a surface forming the generator accommodating space S2 other than the end face.

[0031] According to the above configuration, a portion of the working fluid flowing through the working fluid passage S4 is bled into the generator accommodating space S2 via the first gap S1 and the through hole 54, and can be discharged from the generator accommodating space S2 after cooling the generator 3. Because the generator 3 can be cooled by such a simple structure, the power generation turbine 1 can be prevented from becoming complicated.

[0032] 1 and 2, the power-generating turbine 1 according to some embodiments includes at least one magnetic bearing 7 disposed between the generator 3 and one rotor blade 41 in the axial direction and configured to rotatably support the rotating shaft 2. The inner casing 5 described above has the bearing accommodating space S3, which is connected to the generator accommodating space S2 and the first gap S1 and accommodates the rotating shaft 2 and the magnetic bearing 7, formed between the generator accommodating space S2 in the axial direction and the first gap S1.

[0033] According to the above configuration, the working fluid (bleed air) can flow between the generator accommodating space S2 and the first gap S1 through the bearing accommodating space S3 that accommodates the magnetic bearing 7 that does not require lubricating oil. In this case, since there is no need to provide a separate flow path for the working fluid to flow between the generator accommodating space S2 and the first gap S1, it is possible to suppress the power generation turbine 1 from becoming larger and more complicated.

[0034] 1, a power-generating turbine 1 according to some embodiments is configured so that a working fluid flows through a working fluid flow passage S4 from the other side to the one side in the axial direction. The blade portions 44, 46 of the one-side rotor blade 41 and the other-side rotor blade 42 are arranged in the working fluid flow passage S4. The other-side rotor blade 42 is a first stage rotor blade, and the one-side rotor blade 41 is a second stage rotor blade.

[0035] In the illustrated embodiment, the power-generating turbine 1 includes a one-side stator vane (second stage stator vane) 81 provided between the one-side rotor blade 41 and the other-side rotor blade 42, and a other-side stator vane (first stage stator vane) 82 provided on the other side in the axial direction of the other-side rotor blade 42. Each of the one-side stator vane 81 and the other-side stator vane 82 includes blade portions 83, 85 supported from the radially outer side by the inner circumferential surface 61 of the outer casing 6, and annular inner stator vane support portions 84, 86 that support the blade portions 83, 85 from the radially inner side.

[0036] 1, the main flow of the working fluid flowing through the working fluid passage S4 flows in the order of the other-side columnar passage S43, the annular passage S41, and the one-side columnar passage S42. The bleed air, which is a part of the working fluid flowing through the working fluid passage S4, flows in the order of the first gap S1, the bearing accommodating space S3, the generator accommodating space S2, the through hole 54, and the one-side columnar passage S42.

[0037] According to the above configuration, the bleed air, which is a part of the working fluid that has passed through the turbine rotor blades 4, can be caused to flow into the generator accommodating space S2 through the first gap S1. Since the working fluid that flows into the generator accommodating space S2 expands and has a lowered temperature when passing through the turbine rotor blades 4, the generator 3 can be effectively cooled by the working fluid.

[0038] In some embodiments, the above-described power generating turbine 1 further includes a resistor 12 for generating a pressure loss, which is provided on the one axial side of the one rotor blade 41 in the working fluid flow path S4, as shown in Fig. 1. The resistor 12 generates a pressure loss in the working fluid flow path S4, thereby making the pressure in the working fluid flow path S4 between the resistor 12 and the one rotor blade 41 greater than the pressure in the bearing accommodating space S3.

[0039] In the illustrated embodiment, the above-mentioned casing support parts 11 also function as resistors 12. Measures for increasing the pressure loss in the working fluid flow path S4 by the casing support parts 11 include, for example, increasing the number or thickness of the casing support parts 11, or shifting one end of the casing support parts 11 in the axial direction relative to the other end in the circumferential direction. The resistors 12 may be, for example, a throttle part provided in the working fluid flow path S4 to reduce the opening area of ​​the working fluid flow path S4.

[0040] According to the above configuration, by providing the resistor 12 in the working fluid flow path S4 and making the pressure in the working fluid flow path S4 between the resistor 12 and the one rotor blade 41 higher than the pressure in the bearing accommodating space S3, it is possible to guide the working fluid to the generator accommodating space S2 through the first gap S1 due to the pressure difference, and to discharge the working fluid from the generator accommodating space S2 through the through hole 54. In this case, since there is no need to separately provide a fan or the like for circulating the working fluid in the generator accommodating space S2, an increase in the number of devices in the power generation turbine 1 can be suppressed, and an increase in the power consumption of the power generation turbine 1 can also be suppressed.

[0041] As shown in Fig. 2, the power generation turbine 1 according to some embodiments is configured so that the working fluid flows through a working fluid flow passage S4 from the one side to the other side in the axial direction. The blade portions 44, 46 of the one-side rotor blade 41 and the other-side rotor blade 42 are arranged in the working fluid flow passage S4. The one-side rotor blade 41 is a first stage rotor blade, and the other-side rotor blade 42 is a second stage rotor blade.

[0042] In the illustrated embodiment, the power-generating turbine 1 includes a one-side stator vane (first stage stator vane) 81A provided on the one side in the axial direction relative to the one-side rotor blade 41, and a other-side stator vane (second stage stator vane) 82A provided between the one-side rotor blade 41 and the other-side rotor blade 42. The one-side stator vane 81A includes a blade portion 83A supported from the radially outer side by the inner circumferential surface 61 of the outer casing 6, and supported from the radially inner side by the outer circumferential surface 53 of the inner casing 5. The other-side stator vane 82A includes a blade portion 84A supported from the radially outer side by the inner circumferential surface 61 of the outer casing 6, and an annular inner stator vane support portion 85A that supports the blade portion 84A from the radially inner side.

[0043] 2, the main flow of the working fluid flowing through the working fluid flow passage S4 flows in the order of the one-side columnar flow passage S42, the annular flow passage S41, and the other-side columnar flow passage S43. The bleed air, which is a part of the working fluid flowing through the working fluid flow passage S4, flows in the order of the through hole 54, the generator accommodating space S2, the bearing accommodating space S3, the first gap S1, and the other-side columnar flow passage S43.

[0044] According to the above configuration, the generator 3 can be cooled by causing a portion of the working fluid before being introduced into the turbine rotor blades 4 to flow into the generator accommodating space S2 through the through-holes 54. Then, by mixing the working fluid (bleed air) whose enthalpy has been increased by recovering thermal energy from the generator 3 with the working fluid (main flow) introduced into the turbine rotor blades 4 through the first gap S1, the recovered power in the turbine rotor blades 4 can be increased, and the output of the power-generating turbine 1 can be increased.

[0045] (Balance Hall) Each of Fig. 4 and Fig. 5 is a schematic cross-sectional view along the axial direction near the turbine rotor blade 4 of the power generation turbine 1 according to one embodiment of the present disclosure. As shown in Fig. 2, the power generation turbine 1 according to some embodiments includes the above-mentioned rotating shaft 2, generator 3, turbine rotor blade 4, inner casing 5, and outer casing 6, and the working fluid of the power generation turbine 1 is configured to flow through the working fluid flow path S4 from the one side to the other side in the axial direction. As shown in Fig. 4, the disk portion 43 of the one-side rotor blade 41 described above has a first balance hole 48 penetrating in the axial direction. The first balance hole 48 is configured so that the working fluid (bleed air) guided from the bearing housing space S3 to the first gap S1 flows into it.

[0046] In the embodiment shown in FIG. 4, the working fluid (bleed air) guided from the bearing accommodating space S3 to the first gap S1 passes through the first balance hole 48, and then mixes with the working fluid (main flow) that has passed through the one-side rotor blade 41 between the one-side rotor blade 41 and the other-side rotor blade 42.

[0047] According to the above configuration, the working fluid (bleed air) guided from the bearing accommodation space S3 to the first gap S1 passes through the first balance holes 48, and is mixed with the working fluid (main flow) that has passed through the one rotor blade 41, downstream in the flow direction of the working fluid from the one rotor blade 41 in which the first balance holes 48 are formed. In this case, the pressure loss when the bleed air and the main flow are mixed can be reduced compared to the case where the working fluid (bleed air) guided from the bearing accommodation space S3 to the first gap S1 is mixed with the working fluid introduced into the one rotor blade 41 through the first gap S1.

[0048] 5, in some embodiments, the disk portion 43 of the one rotor blade 41 has a first balance hole 48 penetrating in the axial direction, and the disk portion 45 of the other rotor blade 42 has a second balance hole 49 penetrating in the axial direction. The first balance hole 48 is configured so that the working fluid (bleed air) guided from the bearing accommodating space S3 to the first gap S1 flows in. The second balance hole 49 is formed outside the first balance hole 48 in the radial direction of the rotating shaft 2, and is configured so that the working fluid that has passed through the first balance hole 48 flows in.

[0049] In the embodiment shown in FIG. 5, the working fluid (bleed air) guided from the bearing accommodating space S3 to the first gap S1 passes through the first balance hole 48 and the second balance hole 49, and then mixes with the working fluid (main flow) that has passed through the other-side rotor blade 42 in the other-side columnar flow passage S43.

[0050] In the embodiment shown in FIG. 5, the turbine rotor blade 4 further includes a connecting portion 47 having one end connected to the disk portion 43 of the one rotor blade 41 and the other end connected to the disk portion 45 of the other rotor blade 42. An outer peripheral surface 471 of the connecting portion 47 faces the inner peripheral surface 851A of the inner stator vane support portion 85A described above with a gap therebetween. A seal structure 13 for sealing the gap between the outer peripheral surface 471 and the inner peripheral surface 851A is provided between the outer peripheral surface 471 of the connecting portion 47 and the inner peripheral surface 851A of the inner stator vane support portion 85A. In the illustrated embodiment, the seal structure 13 is a labyrinth seal formed on the inner peripheral surface 851A. The gap between the outer peripheral surface 471 and the inner peripheral surface 851A is formed outside the first balance hole 48 in the radial direction of the rotating shaft 2 and inside the second balance hole 49 in the radial direction of the rotating shaft 2. The above-mentioned first balance hole 48 passes through the second balance hole 49 after passing through the gap between the outer circumferential surface 471 and the inner circumferential surface 851A.

[0051] According to the above configuration, the working fluid (bleed air) that has passed through the first balance holes 48 is pushed outward in the radial direction of the rotating shaft 2 by the rotation of the rotating shaft 2. By forming the second balance holes 49 further outward in the radial direction of the rotating shaft 2 than the first balance holes 48, the working fluid (bleed air) that has passed through the first balance holes 48 easily flows into the second balance holes 49. By making the working fluid (bleed air) that is guided from the bearing accommodation space S3 to the first gap S1 pass not only through the first balance holes 48 but also through the second balance holes 49, it is possible to further reduce the pressure loss when the bleed air and the mainstream are mixed.

[0052] Each of Figures 6 and 7 is a schematic cross-sectional view along the axial direction of a power generation turbine 1 according to an embodiment of the present disclosure. In some embodiments, as shown in Figures 6 and 7, the power generation turbine 1 described above includes the rotating shaft 2, the generator 3, the turbine rotor blades 4, the inner casing 5, and the outer casing 6 described above, and the working fluid of the power generation turbine 1 is configured to flow through the working fluid flow path S4 from the one side to the other side in the axial direction. The power generation turbine 1 described above further includes an extraction line 9 having one end 91 connected to the outer opening 541 of the at least one through hole 54 described above.

[0053] In the embodiment shown in Fig. 6 and Fig. 7, the bleed line 9 has an internal flow passage 90 therein through which the working fluid flows. The outer openings 541 of the plurality of through holes 54 are collectively connected to one end 91 arranged in the one-side columnar flow passage S42 and communicate with the internal flow passage 90. The working fluid (bleed air) introduced into the generator accommodating space S2 flows into the bleed air line 9 from the generator accommodating space S2 through the through holes 54. The working fluid (bleed air) flowing through the through holes 54 and the bleed air line 9 is not mixed with the working fluid (main flow) flowing through the one-side columnar flow passage S42.

[0054] According to the above configuration, by connecting one end 91 of the extraction line 9 to the outer opening 541 of at least one of the through holes 54, the working fluid (bleed air) whose enthalpy has been increased by recovering thermal energy from the generator 3 can be recovered by the extraction line 9, and the enthalpy of the recovered working fluid (bleed air) can be used for various purposes.

[0055] 6 and 7, the power generation turbine 1 may include a flow rate control valve 93 that is provided in the extraction line 9 and configured to be able to adjust the flow rate of the working fluid flowing through the extraction line 9. The flow rate control valve 93 may be an on-off valve that can adjust the opening degree to fully closed and fully open, or may be an opening degree control valve that can adjust the opening degree to fully closed, fully open, and at least one intermediate opening degree between them.

[0056] As shown in Fig. 6 and Fig. 7, the power generation turbine 1 may include a heat exchanger 94 provided in the extraction line 9 and configured to recover thermal energy to the working fluid flowing through the extraction line 9. The heat exchanger 94 recovers thermal energy to the working fluid, thereby cooling an object to be cooled. The object to be cooled by the heat exchanger 94 may be, for example, a power electronics component 95 of the generator 3. In the illustrated embodiment, the heat exchanger 94 and the power electronics component 95 are accommodated in an internal space 960 of a casing 96, and thermal energy generated by the power electronics component 95 is recovered to the working fluid in the heat exchanger 94.

[0057] (Bleed hole) In the power-generating turbine 1 according to some embodiments, as shown in Fig. 6, the rotating shaft 2 described above has the thrust disk portion 22 described above. The magnetic bearing 7 described above includes the other-side thrust bearing 72 described above. The inner casing 5 described above has at least one bleed hole 10 formed therein. The bleed hole 10 has an outer opening 10A formed in the outer circumferential surface 53 that forms the annular flow passage S41 (working fluid flow passage S4) on the outer circumferential side of the bearing accommodating space S3, and an inner opening 10B formed in the inner surface 57 that forms the bearing accommodating space S3 on the other side in the axial direction than the other-side thrust bearing 72.

[0058] The bleed hole 10 is not limited to the illustrated embodiment, and may be any shape that allows the working fluid to flow between the annular passage S41 and the bearing accommodating space S3. In the illustrated embodiment, the bleed hole 10 is formed linearly along the radial direction from the outer opening 10A to the inner opening 10B, but is not limited to this shape.

[0059] A portion of the working fluid (main flow) introduced into the turbine rotor blade 4 can be caused to flow into the bearing housing space S3 through the bleed hole 10. The working fluid (bleed air) that has flowed into the bearing housing space S3 is divided into one-side bleed air that flows through the bearing housing space S3 toward the one side in the axial direction, and another-side bleed air that flows through the bearing housing space S3 toward the other side in the axial direction.

[0060] In the illustrated embodiment, the one-side bleed air flows in the following order: the one side in the axial direction from the bleed hole 10 of the bearing accommodation space S3, the generator accommodation space S2, the through hole 54, and the bleed line 9. In the illustrated embodiment, the other-side bleed air flows in the following order: the other side in the axial direction from the bleed hole 10 of the bearing accommodation space S3, the first gap S1, and the first space S44 between the one-side stator vane 81A and the one-side rotor blade 41 in the working fluid flow path S4.

[0061] By driving the turbine rotor blades 4 of the power-generating turbine 1, a thrust force acts on the rotating shaft 2 supporting the turbine rotor blades 4 from the one side toward the other side in the axial direction.

[0062] According to the above configuration, a part of the working fluid (main flow) introduced into the turbine rotor blade 4 can be made to flow into the generator accommodating space S2 through the bleed hole 10 located upstream of the first gap S1 in the flow direction of the working fluid flow passage S4. In this case, the thrust disk portion 22 is pushed from the other side to the one side by the working fluid (one-side bleed) flowing through the generator accommodating space S2 from the other side to the one side in the axial direction, so that the thrust force applied to the rotating shaft 2 can be reduced.

[0063] In the power generation turbine 1 according to some embodiments, as shown in FIG. 6, the at least one turbine rotor blade 4 includes the one-side rotor blade 41 and the other-side rotor blade 42. The power generation turbine 1 further includes a one-side stator blade 81A disposed on the one side in the axial direction relative to the one-side rotor blade 41 and the first gap S1, and the other end 92 (92A, 92B) of the above-mentioned extraction line 9 is connected to either the first space S44 between the one-side stator blade 81A and the one-side rotor blade 41 in the working fluid flow path S4, or the second space S45 on the other side relative to the other-side rotor blade 42 in the working fluid flow path S4. The other end 92 (92A, 92B) of the extraction line 9 is connected to the first space S44 or the second space S45 from the outside in the radial direction. The working fluid (bleed air) introduced into the extraction line 9 is led to the first space S44 or the second space S45.

[0064] When the other end 92 (92B) of the extraction line 9 is connected to the first space S44, the working fluid (extracted air) whose enthalpy has been increased by recovering thermal energy from the generator 3 and the heat exchanger 94 is mixed with the working fluid (main flow) introduced into the turbine rotor blades 4 in the first space S44 through the extraction line 9, thereby increasing the recovered power in the turbine rotor blades 4 and increasing the output of the power generation turbine 1.

[0065] Furthermore, when the other end 92 (92A) of the bleed line 9 is connected to the second space S45, the working fluid (bleed air) that has cooled the generator 3 is mixed in the second space S45 with the working fluid (main flow) that has passed through the other rotor blade 42. In this case, the pressure loss when the bleed air and the main flow are mixed can be reduced compared to when the bleed air is mixed with the main flow introduced into the turbine rotor blade 4.

[0066] In the power generation turbine 1 according to some embodiments, as shown in Fig. 7, the at least one turbine rotor blade 4 described above includes the one-side rotor blade 41 described above and the other-side rotor blade 42 described above. The power generation turbine 1 further includes a one-side stator vane 81A arranged on the one side in the axial direction relative to the one-side rotor blade 41 and the first gap S1, and the other end 92 (92A) of the above-mentioned extraction line 9 is connected to the second space S45 on the other side of the other-side rotor blade 42 in the working fluid flow path S4. The other end 92 (92A) of the extraction line 9 is connected to the second space S45 from the outside in the radial direction. The working fluid (bleed air) introduced into the extraction line 9 is led to the second space S45.

[0067] 7, since the inner casing 5 is not formed with the bleed hole 10, a part of the working fluid (bleed air) flowing through the working fluid flow passage S4 flows in the order of the first gap S1, the bearing accommodating space S3, the generator accommodating space S2, and the bleed air line 9. The working fluid (bleed air) introduced into the bleed air line 9 is led to the second space S45.

[0068] According to the above configuration, when the other end 92 of the bleed line 9 is connected to the second space S45, the working fluid (bleed air) that has cooled the generator 3 is mixed in the second space S45 with the working fluid (main flow) that has passed through the other rotor blade 42. In this case, the pressure loss when the bleed air and the main flow are mixed can be reduced compared to the case where the bleed air is mixed with the main flow introduced into the turbine rotor blade 4.

[0069] (First throttle section) Fig. 8 is a schematic cross-sectional view along the axial direction near the generator housing space S2 and the bearing housing space S3 of the power generation turbine 1 according to one embodiment of the present disclosure. In Fig. 8, the first throttling portion A1 and the second throttling portion A2 are depicted, but it is sufficient if either the first throttling portion A1 or the second throttling portion A2 is present. In the power generation turbine 1 according to some embodiments, as shown in Fig. 8, the rotating shaft 2 described above has the thrust disk portion 22 described above, and the first throttling portion A1 that narrows the flow path of the working fluid is provided between the outer circumferential surface 221 of the thrust disk portion 22 described above and the inner surface 58 of the inner casing 5 that faces the outer circumferential surface 221 with a gap therebetween.

[0070] According to the above configuration, by providing the first throttle portion A1, the thrust disk portion 22 is pushed from the other side to the one side by a pressure difference generated between the one side and the other side in the axial direction of the first throttle portion A1 of the bearing accommodating space S3, thereby reducing the thrust force applied to the rotating shaft 2. By providing the first throttle portion A1 upstream of the generator accommodating space S2 in the flow direction of the bleed air, the rotor 31 of the generator 3 rotates in a relatively low pressure field, thereby reducing windage loss of the rotor 31.

[0071] In the power generation turbine 1 according to some embodiments, as shown in FIG. 8, a second throttling section A2 that narrows the flow path of the working fluid is provided between the outer peripheral surface 33 of the rotor 31 described above and the inner surface (inner peripheral surface) 56A of the inner casing 5 that faces the outer peripheral surface 33 with a gap therebetween.

[0072] In order to rotate the rotor 31 of the generator 3 in a relatively low pressure field, it is preferable that the second throttling portion A2 is provided on the other side in the axial direction. In the illustrated embodiment, the second throttling portion A2 is provided on the other side in the axial direction relative to the permanent magnet 312.

[0073] According to the above configuration, by providing the second throttling portion A2, the rotor 31 is pushed from the other side to the one side by a pressure difference generated between the one side and the other side in the axial direction through the second throttling portion A2 of the gap (outer periphery side gap S22), thereby reducing the thrust force applied to the rotating shaft 2. Furthermore, according to the above configuration, the thrust bearing can be made smaller than when the first throttling portion A1 is provided, thereby preventing the power generation turbine 1 from becoming larger.

[0074] In some embodiments, as shown in Figs. 1, 2, 6 and 7, the inner casing 5 of the power generating turbine 1 includes the stator support portion 51 that supports the stator 32 from the inner circumferential side. The generator accommodating space S2 includes an outer circumferential gap S22, an inner circumferential gap S21, a one-side space S23 and an other-side space S24. The outer circumferential gap S22 is formed between the outer circumferential surface 33 of the rotor 31 and an inner surface 56A of the inner casing 5 that faces the outer circumferential surface 33 with a gap on the outer circumferential side. The inner circumferential gap S21 is formed between the rotor 31 and the stator 32. The one-side space S23 is connected to the outer circumferential gap S22 and the inner circumferential gap S21 on the one side in the axial direction relative to the inner circumferential gap S21. The one-side space S23 is formed by the inner surface on the one side that forms the generator accommodating space S2 of the inner casing 5. The other-side space S24 is connected to the inner circumferential gap S21 on the other side in the axial direction relative to the inner circumferential gap S21. The other-side space S24 is formed by the rotor 31 and the stator support portion 51. The inner openings 542 of each of the plurality of through holes 54 described above are connected to the other-side space S24.

[0075] According to the above configuration, the working fluid (bleed air) introduced into the generator accommodating space S2 passes through the outer peripheral side gap S22, the one side space S23, the inner peripheral side gap S21 and the other side space S24 in that order or in reverse order, so that the rotor 31 and the stator 32 can be effectively cooled as they pass through the generator accommodating space S2.

[0076] (Power generation system) 9 is a schematic diagram of a power generation system 100 including a power generation turbine 1 according to an embodiment of the present disclosure. The power generation system 100 is for recovering cold energy contained in the liquefied gas as electric power via a heat medium for heating the liquefied gas. When the liquefied gas is vaporized, the cold energy is recovered as electric power by the power generation turbine 1 mounted on the power generation system 100.

[0077] The power generation system 100 includes a power generation turbine 1, a heat medium circulation line 101, a liquefied gas supply line 102, a condenser 103, a heating fluid supply line 104, a cold heat pump 105, and an evaporator 106. The power generation turbine 1, the condenser 103, the cold heat pump 105, and the evaporator 106 are each connected to the heat medium circulation line 101. The liquefied gas supply line 102 is connected to the condenser 103. The heating fluid supply line 104 is connected to the evaporator 106. Each of the heat medium circulation line 101, the liquefied gas supply line 102, and the heating fluid supply line 104 includes a flow path, such as a pipe, through which a fluid flows. The power generation system 100 is configured to be driven by the heat medium circulating in the heat medium circulation line 101 while changing its state to liquid or gas.

[0078] (Heat medium circulation line) The heat medium circulation line 101 is configured to circulate a heat medium having a lower freezing point than water. In the following, liquefied natural gas (LNG) is used as a specific example of a liquefied gas, and propane is used as a specific example of a heat medium flowing through the heat medium circulation line 101. However, the present disclosure is also applicable to liquefied gases other than liquefied natural gas (such as liquefied hydrogen), and is also applicable to cases where a heat medium other than propane, such as R1234yf or R1234ze, is used as a heat medium flowing through the heat medium circulation line 101.

[0079] (Condenser) The condenser 103 is configured to condense the working fluid by heat exchange between the heat medium and the liquefied gas. Inside the condenser 103, there are provided a heating side pipe 103A connected to the heat medium circulation line 101 and into which the heat medium circulating through the heat medium circulation line 101 flows, and a heated side pipe 103B connected to the liquefied gas supply line 102 and into which the liquefied gas flowing through the liquefied gas supply line 102 flows. The heat medium flowing through the heating side pipe 103A and the liquefied gas flowing through the heated side pipe 103B are configured to exchange heat. In the condenser 103, the heat medium is cooled and condensed by the heat exchange, and the liquefied gas is heated.

[0080] The liquefied gas supply line 102 upstream of the condenser 103 is connected to a liquefied gas pump 102A, and the further upstream side of the liquefied gas pump 102A is connected to a liquefied gas storage device 102B. When the liquefied gas pump 102A is driven, the liquid liquefied gas stored in the liquefied gas storage device 102B is sent to the liquefied gas supply line 102, flows through the liquefied gas supply line 102 from the upstream side to the downstream side, and is supplied to the condenser 103.

[0081] The liquefied gas vaporized by heat exchange inside the condenser 103 flows through the heated side pipe 103B, and then flows again through the liquefied gas supply line 102 to be supplied as fuel to an engine (not shown) installed downstream of the condenser 103.

[0082] (Heat and cold pump) The cold heat pump 105 is configured to boost the pressure of the heat medium supplied from the condenser 103. When the cold heat pump 105 connected to the heat medium circulation line 101 is driven, the heat medium circulates through the heat medium circulation line 101. The heat medium flows from the condenser 103 to the cold heat pump 105, from the cold heat pump 105 to the evaporator 106, from the evaporator 106 to the power generation turbine 1, and from the power generation turbine 1 to the condenser 103.

[0083] The cold pump 105 may be of any type as long as it can boost the pressure of the heat medium. For example, a turbo pump (such as a centrifugal pump, a mixed flow pump, or an axial flow pump), a positive displacement pump (such as a reciprocating pump or a rotary pump), or a special pump (such as a submersible motor pump) may be used depending on the embodiment.

[0084] (Evaporator) The evaporator 106 is configured to evaporate the heat medium by heat exchange between the heat medium pressurized by the cold heat pump 105 and the heating fluid introduced from outside the power generation system 100. Inside the evaporator 106, there are a heat medium heated side pipe 106A into which the heat medium pressurized by the cold heat pump 105 flows and which is connected to the heat medium circulation line 101, and a heat medium heating side pipe 106B into which the heating fluid introduced from outside the power generation system 100 flows, which is connected to the heating fluid supply line 104. The heat medium flowing through the heat medium heated side pipe 106A and the heating fluid flowing through the heat medium heating side pipe 106B are configured to exchange heat. In the evaporator 106, the heat medium is heated and evaporated by the heat exchange, and the heating fluid is cooled.

[0085] The heating fluid supply line 104 upstream of the evaporator 106 is connected to a heating fluid pump 104A. The heating fluid supply line 104 further upstream of the heating fluid pump 104A is connected to a heating fluid supply source so that heating fluid is introduced from outside the power generation system 100.

[0086] By driving the heating fluid pump 104A, the heating fluid is sent from the heating fluid supply source to the heating fluid supply line 104, flows through the heating fluid supply line 104 from the upstream side to the downstream side, and is supplied to the evaporator 106. Then, the heating fluid cooled by heat exchange inside the evaporator 106 flows through the heat medium heating side pipe 106B, and then flows through the heating fluid supply line 104 again, and is discharged to the outside of the power generation system 100.

[0087] The above-mentioned “heating fluid” may be any fluid that heats the heat medium circulating through the heat medium circulation line 101 as a heat medium in the evaporator 106, and may be steam, hot water, seawater, engine cooling water, or water at room temperature.

[0088] The power generation turbine 1 is configured to be driven by the gaseous heat medium generated in the evaporator 106. The power generation turbine 1 has the generator 3 described above. The power generation turbine 1 is configured to drive the generator 3 by rotating the rotating shaft 2 of the power generation turbine 1 by the gaseous heat medium generated in the evaporator 106. The gaseous heat medium that has driven the power generation turbine 1 flows through the heat medium circulation line 101 toward the condenser 103 described above that is installed downstream of the power generation turbine 1.

[0089] The power generation turbine 1 is provided in a heat medium circulation line 101 configured to circulate a heat medium for heating the liquefied gas. In this case, the heat medium circulated through the heat medium circulation line 101 and introduced into the power generation turbine 1 is at a relatively low temperature by recovering the cold energy of the liquefied gas. By using the heat medium as the working fluid of the power generation turbine 1, a relatively low-temperature working fluid is introduced into the generator housing space S2, so that the generator 3 is effectively cooled.

[0090] 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 represent such a configuration, but also represent 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.

[0091] The present disclosure is not limited to the above-described embodiments, and includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0092] The contents described in the above-mentioned embodiments can be understood, for example, as follows.

[0093] 1) A power generation turbine (1) according to at least one embodiment of the present disclosure comprises: A rotating shaft (2); a generator (3) including a rotor (31) provided on one side of the rotating shaft (2) in the axial direction and a stator (32) arranged on an inner peripheral side of the rotor (31); at least one turbine blade (4) provided on the other side of the rotating shaft (2) in the axial direction relative to the generator (3); an inner casing (5) configured to rotatably accommodate the rotating shaft (2), the inner casing (5) having an opposing surface (52) opposing a disk portion (43) of the at least one turbine rotor blade (4) with a first gap (S1) therebetween, and the inner casing (5) forming a generator accommodating space (S2) communicating with the first gap (S1) and accommodating the generator (3); an outer casing (6) disposed on an outer circumferential side of the inner casing (5) and communicating with the first gap (S1) between the outer casing (6) and the inner casing (5) to form a working fluid flow path (S4) through which a working fluid of the turbine rotor blades (4) flows; The inner casing (5) is formed with at least one through hole (54) having an outer opening (541) formed in an outer surface (55) forming the working fluid flow path (S4) and an inner opening (542) formed in an inner surface (56) forming the generator accommodating space (S2).

[0094] According to the above configuration 1), by making the generator (3) provided on the other side of the rotating shaft (2) an outer rotor type, it is possible to achieve a higher power density and reduce the radial size of the generator (3) and the generator accommodating space (S2) compared to the case where the generator (3) is an inner rotor type. As a result, the working fluid flow path (S4) formed on the outer periphery of the generator accommodating space (S2) can be disposed relatively radially inward, thereby preventing the power generation turbine (1) from becoming large.

[0095] According to the above configuration 1), a part of the working fluid flowing through the working fluid passage (S4) can be bled into the generator accommodating space (S2) via the first gap (S1) and the through hole (54) and discharged from the generator accommodating space (S2) after cooling the generator (3). Since the generator (3) can be cooled by such a simple structure, the power generation turbine (1) can be prevented from becoming complicated.

[0096] 2) In some embodiments, the power generating turbine (1) according to 1) above, at least one magnetic bearing (7) arranged between the generator (3) and the at least one turbine blade (4) in the axial direction and configured to rotatably support the rotating shaft (2); The inner casing (5) is provided between the generator accommodating space (S2) and the first gap (S1) in the axial direction, with a bearing accommodating space (S3) connected to the generator accommodating space (S2) and the first gap (S1) to accommodate the rotating shaft (2) and the at least one magnetic bearing (7).

[0097] According to the above configuration 2), the working fluid (bleed air) can flow between the generator housing space (S2) and the first gap (S1) through the bearing housing space (S3) that houses the magnetic bearing (7) that does not require lubricating oil. In this case, it is not necessary to provide a separate flow path for the working fluid to flow between the generator housing space (S2) and the first gap (S1), so that the power generation turbine (1) can be prevented from becoming large and complicated.

[0098] 3) In some embodiments, the power generating turbine (1) according to 2) above, The working fluid was configured to flow through the working fluid flow path (S4) from the other side to the one side in the axial direction.

[0099] According to the above configuration 3), a part of the working fluid that has passed through the turbine rotor blades (4) can be made to flow into the generator accommodating space (S2) through the first gap (S1). Since the working fluid that flows into the generator accommodating space (S2) expands and has a lowered temperature when passing through the turbine rotor blades (4), the generator (3) can be effectively cooled by the working fluid.

[0100] 4) In some embodiments, the power generating turbine (1) according to 2) above, The working fluid was configured to flow through the working fluid flow path (S4) from the one side to the other side in the axial direction.

[0101] According to the above configuration 4), the generator (3) can be cooled by causing a part of the working fluid before being introduced into the turbine rotor blades (4) to flow into the generator accommodating space (S2) through the through hole (54). Then, the working fluid having increased enthalpy by recovering thermal energy from the generator (3) is mixed with the working fluid introduced into the turbine rotor blades (4) through the first gap (S1), thereby increasing the power recovered in the turbine rotor blades (4) and increasing the output of the power-generating turbine (1).

[0102] 5) In some embodiments, the power generating turbine (1) according to 3) above, The compressor further includes a resistor (12) that generates a pressure loss and is provided on one side of the at least one turbine blade (4) in the axial direction in the working fluid flow path (S4), and the resistor (12) is configured to make the pressure in the working fluid flow path between the resistor (12) and the at least one turbine blade (4) greater than the pressure in the bearing accommodating space (S3).

[0103] According to the above configuration 5), by providing the resistor (12) in the working fluid flow path (S4) and making the pressure of the working fluid flow path between the resistor (12) and the turbine rotor blades (4) higher than the pressure in the bearing housing space (S3), the working fluid can be guided to the generator housing space (S2) through the first gap (S1) by the pressure difference, and the working fluid can be discharged from the generator housing space (S2) through the through hole (54). In this case, there is no need to separately provide a fan or the like for circulating the working fluid in the generator housing space (S2), so that an increase in the number of devices in the power generation turbine (1) can be suppressed, and an increase in the power consumption of the power generation turbine (1) can also be suppressed.

[0104] 6) In some embodiments, the power generating turbine (1) according to 4) above, the disk portion (43) of the at least one rotor blade (4) facing the opposing surface (52) of the inner casing (5) across the first gap (S1) has a first balance hole (48) penetrating therethrough in the axial direction, The first balance hole (48) is configured so that the working fluid introduced from the bearing accommodating space (S3) to the first gap (S1) flows into it.

[0105] According to the above configuration 6), the working fluid (bleed air) guided from the bearing accommodation space (S3) to the first gap (S1) passes through the first balance holes (48), and is mixed with the working fluid (main flow) that has passed through the rotor blade (4) in which the first balance holes (48) are formed, downstream in the flow direction of the working fluid from the rotor blade (4) in which the first balance holes (48) are formed. In this case, the pressure loss when the bleed air and the main flow are mixed can be reduced compared to the case where the working fluid (bleed air) guided from the bearing accommodation space (S3) to the first gap (S1) is mixed with the working fluid introduced into the turbine rotor blade (4) through the first gap (S1).

[0106] 7) In some embodiments, the power generating turbine (1) according to 6) above, The at least one rotor blade (4) is a rotor blade (41) on one side having the first balance hole (48); a second rotor blade (42) provided on the second side in the axial direction relative to the first rotor blade (41), the disk portion (45) of the other rotor blade (42) has a second balance hole (49) penetrating therethrough in the axial direction, The second balance hole (49) is formed radially outward of the rotating shaft (2) relative to the first balance hole (48) and is configured so that the working fluid that has passed through the first balance hole (48) flows into the second balance hole (49).

[0107] According to the above configuration 7), the working fluid (bleed air) that has passed through the first balance holes (48) is pushed outward in the radial direction of the rotating shaft (2) by the rotation of the rotating shaft (2). By forming the second balance holes (49) on the outer side of the first balance holes (48) in the radial direction of the rotating shaft (2), the working fluid (bleed air) that has passed through the first balance holes (48) is more likely to flow into the second balance holes (49). By making the working fluid (bleed air) that has been guided from the bearing accommodation space (S3) to the first gap (S1) pass not only through the first balance holes (48) but also through the second balance holes (49), it is possible to further reduce the pressure loss when the bleed air and the mainstream are mixed.

[0108] 8) In some embodiments, the power generating turbine (1) according to 4) above, The at least one through hole (54) further includes an exhaust line (9) having one end (91) connected to the outer opening (541) of the at least one through hole (54).

[0109] According to the above configuration 8), by connecting one end (91) of the extraction line (9) to the outer opening (541) of at least one of the through holes (54), the working fluid (bleed air) having increased enthalpy as a result of recovering thermal energy from the generator (3) can be recovered by the extraction line (9), and the enthalpy of the recovered working fluid (bleed air) can be used for various purposes.

[0110] 9) In some embodiments, the power generating turbine (1) according to 8) above, And, the rotating shaft (2) has a thrust disk portion (22) protruding radially outward of the rotating shaft (2) in the bearing accommodating space (S3), the at least one magnetic bearing (7) includes a second-side thrust bearing (72) that is disposed on the second side in the axial direction of the rotating shaft (2) relative to the thrust disk portion (22) and faces the thrust disk portion (22) with a gap therebetween, The inner casing (5) is formed with at least one air bleed hole (10) having an outer opening (10A) formed in an outer peripheral surface (53) that forms the working fluid flow path (S4) on the outer peripheral side of the bearing accommodating space (S3), and an inner opening (10B) formed in an inner surface (57) that forms the bearing accommodating space (S3) on the other side in the axial direction relative to the other-side thrust bearing (72).

[0111] According to the above configuration 9), a part of the working fluid introduced into the turbine rotor blades (4) can be made to flow into the generator accommodating space (S2) through the bleed hole (10) located upstream of the first gap (S1) in the flow direction of the working flow passage. In this case, the thrust disk portion (22) is pushed from the other side to the one side by the working fluid (bleed air) flowing through the generator accommodating space (S2) from the other side to the one side in the axial direction, so that the thrust force applied to the rotating shaft (2) can be reduced.

[0112] 10) In some embodiments, the power generating turbine (1) according to 9) above, The at least one rotor blade (4) is One rotor blade (41), a second rotor blade (42) provided on the second side in the axial direction relative to the first rotor blade (41), The power generating turbine (1) comprises: the one-side stator vane (81A) is arranged on the one side in the axial direction relative to the one-side rotor blade (41) and the first gap (S1), The other end (92) of the extraction line (9) is connected to either a first space (S44) between the one-side stator vane (81A) and the one-side rotor blade (41) in the working fluid flow path (S4), or a second space (S45) on the other side of the other-side rotor blade (42).

[0113] According to the configuration of 10) above, when the other end (92) of the extraction line (9) is connected to the first space (S44), the working fluid (extracted air) having increased enthalpy by recovering thermal energy from the generator (3) is mixed with the working fluid (main flow) introduced into the turbine rotor blades (4) in the first space (S44) through the extraction line (9). This makes it possible to increase the power recovered in the turbine rotor blades (4) and to increase the output of the power-generating turbine (1).

[0114] According to the configuration of 10), when the other end (92) of the bleed line (9) is connected to the second space (S45), the working fluid (bleed air) that has cooled the generator (3) is mixed with the working fluid (main flow) that has passed through the other rotor blade (42) in the second space (S45). In this case, the pressure loss caused when the bleed air and the main flow are mixed can be reduced compared to the case where the bleed air is mixed with the main flow introduced into the turbine rotor blade (4).

[0115] 11) In some embodiments, the power generating turbine (1) according to 8) above, The at least one rotor blade (4) is One rotor blade (41), a second rotor blade (42) provided on the second side in the axial direction relative to the first rotor blade (41), The power generating turbine (1) comprises: the one-side stator vane (81A) is arranged on the one side in the axial direction relative to the one-side rotor blade (41) and the first gap (S1), The other end (92) of the extraction line (9) is connected to a second space (S45) on the other side of the other rotor blade (42) in the working fluid flow path (S4).

[0116] According to the configuration of 11) above, when the other end (92) of the bleed line (9) is connected to the second space (S45), the working fluid (bleed air) that has cooled the generator (3) is mixed with the working fluid (main flow) that has passed through the other rotor blade (42) in the second space (S45). In this case, the pressure loss when the bleed air and the main flow are mixed can be reduced compared to the case where the bleed air is mixed with the main flow introduced into the turbine rotor blade (4).

[0117] 12) In some embodiments, the power generation turbine (1) according to any one of 8) to 11) above, the rotating shaft (2) has a thrust disk portion (22) protruding radially outward of the rotating shaft (2) in the bearing accommodating space (S3), A first throttling portion (A1) that narrows the flow path of the working fluid is provided between an outer peripheral surface (221) of the thrust disk portion (22) and an inner surface (58) of the inner casing (5) that faces the outer peripheral surface (221) of the thrust disk portion (22) with a gap therebetween.

[0118] According to the configuration of 12), by providing the first throttle portion (A1), the thrust disk portion (22) is pushed from the other side to the one side by a pressure difference generated between the one side and the other side in the axial direction of the first throttle portion (A1) of the bearing accommodating space (S3), thereby reducing the thrust force applied to the rotating shaft (2). By providing the first throttle portion (A1) upstream of the generator accommodating space (S2) in the flow direction of the bleed air, the rotor (31) of the generator (3) rotates in a relatively low-pressure field, thereby reducing windage loss of the rotor (31).

[0119] 13) In some embodiments, the power generation turbine (1) according to any one of 8) to 11) above, A second throttling section (A2) that narrows the flow path of the working fluid is provided between an outer peripheral surface (33) of the rotor (31) and an inner surface (56A) of the inner casing (5) that faces the outer peripheral surface (33) of the rotor (31) with a gap therebetween.

[0120] According to the configuration of 13) above, by providing the second throttling portion (A2), the rotor (31) is pushed from the other side to the one side by a pressure difference generated between the one side and the other side in the axial direction through the second throttling portion (A2) of the gap (outer circumferential gap S22), thereby reducing the thrust force applied to the rotating shaft (2). Furthermore, according to the configuration of 13) above, the thrust bearing can be made smaller than in the case where the first throttling portion (A1) is provided, thereby preventing the power generation turbine (1) from becoming large.

[0121] 14) In some embodiments, the power generating turbine (1) according to any one of 1) to 13) above, The inner casing (5) includes a stator support portion (51) that supports the stator from an inner peripheral side, The generator accommodation space (S2) is an outer circumferential gap (S22) formed between an outer circumferential surface of the rotor (31) and an inner surface of the inner casing (5) facing the outer circumferential surface of the rotor (31) with a gap on the outer circumferential side; an inner peripheral gap (S21) formed between the rotor (31) and the stator (32); a one-side space (S23) connected to the outer circumferential side gap (S22) and the inner circumferential side gap (S21) on the one side in the axial direction relative to the inner circumferential side gap (S21); a second-side space (S24) connected to the inner-periphery-side gap (S21) on the other side in the axial direction relative to the inner-periphery-side gap (S21), the second-side space (S24) being formed by the rotor (31) and the stator support portion (51), The inner opening (542) of the at least one through hole (54) is connected to the other-side space (S24).

[0122] According to the above configuration 14), the working fluid (bleed air) introduced into the generator accommodating space (S2) passes through the outer circumferential side gap (S22), the one-side space (S23), the inner circumferential side gap (S21) and the other-side space (S24) in that order or in the reverse order, so that the rotor (31) and the stator (32) can be effectively cooled while passing through the generator accommodating space (S2).

[0123] 15) In some embodiments, the power generating turbine (1) according to any one of 1) to 14) above, The power generation turbine (1) is provided in a heat medium circulation line (101) configured to circulate a heat medium for heating liquefied gas.

[0124] According to the above configuration 15), the heat medium circulating through the heat medium circulation line (101) and introduced into the power generation turbine (1) is at a relatively low temperature by recovering cold energy from the liquefied gas. By using the heat medium as the working fluid of the power generation turbine (1), a relatively low-temperature working fluid is introduced into the generator housing space (S2), and therefore the generator (3) is effectively cooled. [Explanation of symbols]

[0125] 1. Power generating turbines 2 Rotating shaft 3. Generator 4 Turbine blades 5 Inner casing 6 Outer casing 7. Bearings 9 Extraction Line 10 Bleed hole 11 Casing support 21 One end 22 Thrust disk section 31 Rotor 32 Stator 41 One side rotor blade 42 Other side rotor blade 43,45 Disc section 44,46 Wings 51 Stator support 52 Opposite Surface 53 Outer surface 54 Through hole 55 External surface 56 Inside 61 Inner surface 71,72 Thrust bearings 73,74 Journal bearings 81,81A One side stator vane 82, 82A Other side stator vane 83,83A,84A wing section 84,85A Inner stationary blade support part 311 Magnet support 312 Permanent Magnets 313 Radial extension 314 Axial extension 315 Slope 321 Static coil section 541 External opening 542 Inner opening CA center axis S1 First gap S2 Generator housing space S3 Bearing accommodation space S4 Working fluid flow path S21 Inner circumference clearance S22 Outer gap S23 One-sided space S24 Other side space S41 Annular flow path S42 One-side columnar channel S43 Other side column channel

Claims

1. A rotating shaft, a generator including a rotor provided on one axial side of the rotating shaft and a stator disposed on the inner peripheral side of the rotor, at least one turbine blade provided on the other axial side of the rotating shaft than the generator, an inner casing configured to rotatably accommodate the rotating shaft, having an opposing surface facing the disk portion of the at least one turbine blade with a first gap therebetween, and forming a generator accommodation space communicating with the first gap and accommodating the generator; an outer casing disposed on the outer peripheral side of the inner casing and forming an operating fluid flow path communicating with the first gap between the inner casing and the operating fluid flowing through the turbine blade, the power generation turbine comprising: The inner casing is formed with at least one through hole having an outer opening formed on an outer surface forming the operating fluid flow path and an inner opening formed on an inner surface forming the generator accommodation space, The power generation turbine further includes at least one magnetic bearing disposed between the generator and the at least one turbine blade in the axial direction and configured to rotatably support the rotating shaft, The inner casing forms a bearing accommodation space that is connected to the generator accommodation space and the first gap between the generator accommodation space and the first gap in the axial direction and accommodates the rotating shaft and the at least one magnetic bearing, The working fluid is configured to flow from the other axial side to the one axial side through the working fluid flow path, The power generation turbine further includes a resistor that causes a pressure loss and is provided on the one axial side of the at least one turbine blade in the working fluid flow path, and the pressure in the working fluid flow path between the resistor and the at least one turbine blade is made greater than the pressure in the bearing accommodation space. Power generation turbine.

2. A rotating shaft, a generator including a rotor provided on one axial side of the rotating shaft and a stator disposed on the inner peripheral side of the rotor, at least one turbine blade provided on the other axial side of the rotating shaft than the generator, An inner casing configured to rotatably accommodate the rotating shaft, having opposing surfaces facing the disk portion of the at least one turbine moving blade with a first gap therebetween, and forming a generator accommodation space that communicates with the first gap and accommodates the generator. A power generation turbine comprising an outer casing disposed on the outer peripheral side of the inner casing and forming a working fluid flow path that communicates with the first gap and through which the working fluid of the turbine moving blade flows between the inner casing and the outer casing. The inner casing is formed with at least one through hole having an outer opening formed on an outer surface forming the working fluid flow path and an inner opening formed on an inner surface forming the generator accommodation space. The power generation turbine further includes at least one magnetic bearing disposed between the generator in the axial direction and the at least one turbine moving blade and configured to rotatably support the rotating shaft. The inner casing forms a bearing accommodation space that is connected to the generator accommodation space and the first gap between the generator accommodation space in the axial direction and the first gap and accommodates the rotating shaft and the at least one magnetic bearing. The working fluid is configured to flow through the working fluid flow path from one side in the axial direction to the other side. The disk portion of the at least one moving blade facing the opposing surface of the inner casing with the first gap therebetween has a first balance hole penetrating in the axial direction. The first balance hole is configured such that the working fluid led from the bearing accommodation space to the first gap flows in. Power generation turbine.

3. The at least one turbine moving blade One-sided moving blades having the first balance hole, And the other-sided moving blades provided on the other side in the axial direction than the one-sided moving blades, The disk portion of the other-sided moving blade has a second balance hole penetrating in the axial direction. The second balance hole is formed on the outer side in the radial direction of the rotating shaft than the first balance hole and is configured such that the working fluid that has passed through the first balance hole flows in. The power generation turbine according to claim 2.

4. A rotating shaft, A generator including a rotor provided on one side in the axial direction of the rotating shaft and a stator disposed on the inner peripheral side of the rotor. At least one turbine moving blade provided on the other side in the axial direction of the rotating shaft with respect to the generator; An inner casing configured to rotatably accommodate the rotating shaft, having an opposing surface facing the disk portion of the at least one turbine moving blade with a first gap therebetween, and forming a generator accommodation space that communicates with the first gap and accommodates the generator; An outer casing disposed on the outer peripheral side of the inner casing, and forming an operating fluid flow path that communicates with the first gap and through which the operating fluid of the turbine moving blade flows between the outer casing and the inner casing; a power generation turbine comprising: The inner casing is formed with at least one through hole having an outer opening formed on an outer surface forming the operating fluid flow path and an inner opening formed on an inner surface forming the generator accommodation space; The power generation turbine further includes at least one magnetic bearing disposed between the generator and the at least one turbine moving blade in the axial direction and configured to rotatably support the rotating shaft; The inner casing forms a bearing accommodation space that is connected to the generator accommodation space and the first gap between the generator accommodation space and the first gap in the axial direction and accommodates the rotating shaft and the at least one magnetic bearing; The operating fluid is configured to flow through the operating fluid flow path from the one side in the axial direction toward the other side; The power generation turbine further includes an extraction line having one end connected to the outer opening of the at least one through hole; The at least one turbine moving blade includes: A one-side moving blade; And the other-side moving blade provided on the other side in the axial direction with respect to the one-side moving blade; The power generation turbine includes: Further includes a one-side stationary blade disposed on the one side in the axial direction with respect to the one-side moving blade and the first gap; The other end of the extraction line is connected to a second space on the other side of the other-side moving blade in the operating fluid flow path; Power generation turbine.

5. The rotating shaft has a thrust disk portion protruding radially outward of the rotating shaft in the bearing accommodation space; A first throttle portion for narrowing the flow path of the working fluid is provided between the outer peripheral surface of the thrust disk portion and the inner surface of the inner casing facing the outer peripheral surface of the thrust disk portion with a gap therebetween; The power generation turbine according to claim 4.

6. A second throttle portion for narrowing the flow path of the working fluid is provided between the outer peripheral surface of the rotor and the inner surface of the inner casing that faces the outer peripheral surface of the rotor with a gap on the outer peripheral side thereof. The turbine for power generation according to claim 4.

7. The inner casing includes a stator support portion that supports the stator from the inner peripheral side. The generator accommodation space includes an outer peripheral side gap formed between the outer peripheral surface of the rotor and the inner surface of the inner casing that faces the outer peripheral surface of the rotor with a gap on the outer peripheral side thereof, an inner peripheral side gap formed between the rotor and the stator, a one-side space connected to the outer peripheral side gap and the inner peripheral side gap on one side in the axial direction with respect to the inner peripheral side gap, and a the other-side space connected to the inner peripheral side gap on the other side in the axial direction with respect to the inner peripheral side gap, and formed by the rotor and the stator support portion. The inner opening of the at least one through hole is connected to the other-side space. The inner opening of the at least one through hole is connected to the other-side space. The turbine for power generation according to any one of claims 1 to 4.

8. The turbine for power generation is provided in a heat medium circulation line configured to circulate a heat medium for heating liquefied gas. The turbine for power generation according to any one of claims 1 to 4.

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