WO2024190045A1 - Power generation turbine - Google Patents

Abstract

This power generation turbine includes: a rotary shaft; a generator including a rotor provided on one side of the rotary shaft and a stator disposed on an inner circumferential side of the rotor; a turbine rotor blade provided more to the other side of the rotary shaft than the 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 generator housing space which communicates with the gap and houses the generator; and an outer casing that is disposed on an outer circumferential side of the inner casing and that forms, in a space 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 includes a 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 housing space.

Description

Power generation turbines

The present disclosure relates to turbines for power generation.
This application claims priority based on Japanese Patent Application No. 2023-040211, filed with the Japan Patent Office on March 15, 2023, the contents of which are incorporated herein by reference.

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

The ORC (Organic Rankine Cycle) is known as a cold energy power generation cycle that uses liquefied natural gas. In the ORC, 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 this steam is introduced into a cold energy power generation turbine to generate power.

Patent Document 1 discloses a cold energy power generation turbine in which two radial turbines and a generator are arranged coaxially within 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 located in the center of the shaft, and radial turbines are located at both ends of the shaft.

Japanese Patent Application Publication No. 8-218816

Generators require cooling because they rotate at high speeds, 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 the equipment required for cooling and cooling channels. For this reason, there is a concern that the cold energy power generation device will become complicated and large.

In view of the above, at least one embodiment of the present disclosure aims to provide a power generation turbine that can cool a generator while minimizing the complexity and size of the structure.

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, the inner casing 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.

At least one embodiment of the present disclosure provides a power generation turbine that can cool a generator while minimizing the complexity and size of the structure.

1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. 1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. 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. 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. 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. 1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. 1 is a schematic cross-sectional axial view of a power generating turbine according to an embodiment of the present disclosure; FIG. 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. FIG. 1 is a schematic diagram of a power generation system including a power generating turbine according to an 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.

(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 a certain direction.

As shown in Figures 1 and 2, the power generation turbine 1 according to some embodiments comprises the rotating shaft 2, a generator 3 including a rotor 31 provided on one axial side (left side in the figure) of the rotating shaft 2 and a stator 32 provided on the inner circumferential side (radially inward) of the rotor 31, and at least one turbine blade 4 provided on the other axial side (right side in the figure) of the rotating shaft 2 relative to the generator 3. In this 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.

(Generator)
The rotor 31 includes a magnet support portion 311 that is cantilevered on the one end portion 21 of the rotating shaft 2, and a permanent magnet 312 that is supported from the outer periphery (radially outward) by the magnet support portion 311. The stator 32 has a stationary coil portion 321 that is disposed on the inner periphery side of the permanent magnet 312 so as to face the inner periphery side of the permanent magnet 312 with an inner periphery side gap S21 therebetween.

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

The permanent magnet 312 is supported on the inner circumferential side of the axially extending portion 314. The stator 32 is disposed on the one side in the axial direction of the one end 21 of the rotating shaft 2, and is fixed 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 circumferential side.

(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 made small, thereby improving the performance of the power generation turbine 1.

Each of the one-side rotor blade 41 and the other-side rotor blade 42 includes a disk portion 43, 45 whose inner circumferential end is attached to the other end of the rotating shaft 2 in the axial direction, protruding radially outward in a disk shape, and a blade portion 44, 46 provided on the outer periphery of the disk portion 43, 45.

(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 periphery (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 therein a generator housing space S2 that houses the generator 3.

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.

(Bearings)
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.

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

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 a second-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.

(Outer casing)
1 to 3, the outer casing 6 is disposed on the outer periphery (radially outer side) 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.

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

(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 accommodation space S2 is omitted. In the embodiment shown in FIGS. 1 to 3, the power generation turbine 1 includes at least one casing support 11 that extends an annular flow path S41 along the radial direction of the rotating shaft 2. One end of the casing support 11 is connected to an inner circumferential surface 61 of the outer casing 6, and the other end is connected to an outer circumferential surface 53 of the inner casing 5. The inner casing 5 is supported by the outer casing 6 by the casing support 11. The first gap S1 is connected to a working fluid flow path S4 between one end of the one rotor blade 41 and the other end of the casing support 11, and communicates with the working fluid flow path S4.

The casing support part 11 is arranged so that at least a portion of it overlaps with the generator storage 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 to promote cooling of the generator 3. It is sufficient that at least one casing support part 11 is arranged along the axial direction, and it is sufficient that at least one is also arranged in the circumferential direction.

With the above configuration, by making the generator 3 provided on the other side of the rotating shaft 2 an outer rotor type, a higher output density can be achieved and the radial size of the generator 3 and the generator housing space S2 can be reduced 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 housing space S2 can be positioned relatively radially inward, preventing the power generation turbine 1 from becoming too large.

(Through hole)
1 and 2, the above-mentioned inner casing 5 is formed with at least one (in the illustrated example, multiple) through hole 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 multiple through holes 54 are arranged at intervals from one another in the circumferential direction of the rotating shaft 2.

The shape of each of the multiple through holes 54 is not limited to the illustrated embodiment, as long as the working fluid can flow between the generator storage space S2 and the outside of the inner casing 5. In the illustrated embodiment, each of the multiple 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 one side of the axial direction of the inner casing 5, but in other embodiments, it may be formed on the outer peripheral surface 53. Also, in the illustrated embodiment, the inner opening 542 is formed on the end face on the other side of 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 storage space S2 other than the end face.

With the above configuration, a portion of the working fluid flowing through the working fluid passage S4 via the first gap S1 and the through hole 54 can be extracted into the generator housing space S2, and after cooling the generator 3, it can be discharged from the generator housing space S2. Because the generator 3 can be cooled with such a simple structure, the complexity of the power generation turbine 1 can be suppressed.

As shown in Figs. 1 and 2, the power generating turbine 1 according to some embodiments includes at least one magnetic bearing 7 arranged 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 above-mentioned bearing housing space S3 formed between the generator housing space S2 in the axial direction and the first gap S1, and connected to the generator housing space S2 and the first gap S1 to house the rotating shaft 2 and the magnetic bearing 7.

With the above configuration, the generator housing space S2 and the first gap S1 can allow the working fluid (bleed air) to flow through the bearing housing space S3, which houses the magnetic bearing 7 that does not require lubricating oil. In this case, there is no need to provide a separate flow path for the working fluid to flow between the generator housing space S2 and the first gap S1, which prevents the power generation turbine 1 from becoming larger and more complicated.

As shown in FIG. 1, the power generation turbine 1 according to some embodiments is configured so that the working fluid flows through the working fluid flow path 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 path S4. The other-side rotor blade 42 is the first stage rotor blade, and the one-side rotor blade 41 is the second stage rotor blade.

In the illustrated embodiment, the power generation turbine 1 includes a first-side stator vane (second stage stator vane) 81 provided between the first-side rotor blade 41 and the second-side rotor blade 42, and a second-side stator vane (first stage stator vane) 82 provided on the other side in the axial direction of the second-side rotor blade 42. Each of the first-side stator vane 81 and the second-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.

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

With the above configuration, the bleed air, which is part of the working fluid that has passed through the turbine rotor blades 4, can flow into the generator housing space S2 through the first gap S1. The working fluid that flows into the generator housing space S2 expands and drops in temperature as it passes through the turbine rotor blades 4, so the generator 3 can be effectively cooled by the working fluid.

In some embodiments, the power generation turbine 1 described above further includes a resistor 12 that generates a pressure loss and 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 housing space S3.

In the illustrated embodiment, the casing support 11 also functions as a resistor 12. Measures for increasing the pressure loss in the working fluid flow path S4 using the casing support 11 include, for example, increasing the number or thickness of the casing support 11, or shifting one end of the casing support 11 in the axial direction in the circumferential direction relative to the other end. The resistor 12 may be a throttle section or the like that is provided in the working fluid flow path S4 and reduces the opening area of the working fluid flow path S4.

According to the above configuration, by providing a 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 greater 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 due to the pressure difference, and the working fluid can be discharged from the generator housing 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 housing space S2, an increase in the number of pieces of equipment 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.

As shown in FIG. 2, the power generation turbine 1 according to some embodiments is configured so that the working fluid flows through the working fluid flow path 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 path S4. The one-side rotor blade 41 is the first stage rotor blade, and the other-side rotor blade 42 is the second stage rotor blade.

In the illustrated embodiment, the power generation turbine 1 includes a first-side stator vane (first stage stator vane) 81A provided on the one side of the first-side rotor blade 41 in the axial direction, and a second-side stator vane (second stage stator vane) 82A provided between the first-side rotor blade 41 and the second-side rotor blade 42. The first-side stator vane 81A includes a blade portion 83A supported from the radial outside by the inner circumferential surface 61 of the outer casing 6 and supported from the radial inside by the outer circumferential surface 53 of the inner casing 5. The second-side stator vane 82A includes a blade portion 84A supported from the radial outside 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 radial inside.

In the embodiment shown in FIG. 2, the main stream of the working fluid flowing through the working fluid flow path S4 flows in the order of the one-side columnar flow path S42, the annular flow path S41, and the other-side columnar flow path S43. The bleed air, which is part of the working fluid flowing through the working fluid flow path S4, flows in the order of the through hole 54, the generator housing space S2, the bearing housing space S3, the first gap S1, and the other-side columnar flow path S43.

With the above configuration, the generator 3 can be cooled by allowing a portion of the working fluid before being introduced into the turbine rotor blades 4 to flow into the generator housing space S2 through the through holes 54. Then, by mixing the working fluid (bleed air) that has recovered thermal energy from the generator 3 and has increased enthalpy 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.

(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, the generator 3, the turbine rotor blade 4, the inner casing 5, and the 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 accommodation space S3 to the first gap S1 flows in.

In the embodiment shown in FIG. 4, the working fluid (bleed air) guided from the bearing housing 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.

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

In some embodiments, as shown in FIG. 5, the disk portion 43 of the one-side rotor blade 41 has a first balance hole 48 penetrating in the axial direction, and the disk portion 45 of the other-side rotor blade 42 has a second balance hole 49 penetrating in the axial direction. The first balance hole 48 is configured to receive the working fluid (bleed air) guided from the bearing accommodating space S3 to the first gap S1. The second balance hole 49 is formed radially outward of the rotating shaft 2 from the first balance hole 48, and is configured to receive the working fluid that has passed through the first balance hole 48.

In the embodiment shown in FIG. 5, the working fluid (bleed air) guided from the bearing housing 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 rotor blade 42 in the other columnar flow passage S43.

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. The 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 radially outward of the rotating shaft 2 from the first balance hole 48 and is formed radially inward of the rotating shaft 2 from the second balance hole 49. The first balance hole 48 described above passes through the gap between the outer peripheral surface 471 and the inner peripheral surface 851A, and then passes through the second balance hole 49.

With the above configuration, the working fluid (bleed air) that passes through the first balance hole 48 is pushed outward in the radial direction of the rotating shaft 2 due to the rotation of the rotating shaft 2. By forming the second balance hole 49 further outward in the radial direction of the rotating shaft 2 than the first balance hole 48, the working fluid (bleed air) that passes through the first balance hole 48 is more likely to flow into the second balance hole 49. By passing the working fluid (bleed air) guided from the bearing accommodation space S3 to the first gap S1 through not only the first balance hole 48 but also the second balance hole 49, the pressure loss when the bleed air and the main flow are mixed can be further reduced.

6 and 7 are schematic cross-sectional views along the axial direction of a power generation turbine 1 according to one embodiment of the present disclosure. In some embodiments, as shown in FIGS. 6 and 7, the power generation turbine 1 described above includes the rotating shaft 2, generator 3, turbine rotor blades 4, inner casing 5, and 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 at least one through hole 54 described above.

In the embodiment shown in Figures 6 and 7, the bleed line 9 has an internal flow passage 90 therein through which the working fluid flows. The outer openings 541 of each of the multiple through holes 54 are connected together 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 from the generator accommodating space S2 through the through holes 54 and into the bleed line 9. The working fluid (bleed air) flowing through the through holes 54 and the bleed line 9 is not mixed with the working fluid (main flow) flowing through the one-side columnar flow passage S42.

With the above configuration, by connecting one end 91 of the extraction line 9 to the outer opening 541 of at least one through hole 54, the working fluid (extracted air) with 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 (extracted air) can be used for a variety of purposes.

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

6 and 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 object to be cooled is cooled by recovering thermal energy to the working fluid in the heat exchanger 94. 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 housed 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.

(Bleed hole)
In the power-generating turbine 1 according to some embodiments, as shown in Fig. 6, the rotating shaft 2 has the thrust disk portion 22. The magnetic bearing 7 includes the other-side thrust bearing 72. The inner casing 5 has at least one bleed hole 10. The bleed hole 10 has an outer opening 10A formed in the outer circumferential surface 53 that forms the annular flow path S41 (working fluid flow path 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.

The bleed hole 10 is not limited to the embodiment shown in the figure, as long as the working fluid can flow between the annular flow passage S41 and the bearing housing space S3. In the embodiment shown in the figure, the bleed hole 10 is formed in a straight line along the radial direction from the outer opening 10A to the inner opening 10B, but is not limited to this shape.

A portion of the working fluid (main flow) introduced into the turbine rotor blade 4 can be made to flow into the bearing housing space S3 through the bleed hole 10. The working fluid (bleed air) that flows 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 the other-side bleed air that flows through the bearing housing space S3 toward the other side in the axial direction.

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.

By driving the turbine blades 4 of the power generation turbine 1, a thrust force acts on the rotating shaft 2 that supports the turbine blades 4 from one side toward the other side in the axial direction.

The above configuration allows a portion of the working fluid (main flow) introduced into the turbine rotor blades 4 to flow into the generator housing 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 housing space S2 from the other side to the one side in the axial direction, thereby reducing the thrust force on the rotating shaft 2.

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 arranged on the one side in the axial direction from 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 from 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.

When the other end 92 (92B) of the extraction line 9 is connected to the first space S44, the working fluid (extracted air) with increased enthalpy due to thermal energy recovery from the generator 3 and heat exchanger 94 is mixed with the working fluid (main flow) introduced to the turbine rotor blades 4 in the first space S44 through the extraction line 9, thereby increasing the power recovery in the turbine rotor blades 4 and increasing the output of the power generating turbine 1.

In addition, 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 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 when the bleed air is mixed with the main flow introduced into the turbine rotor blade 4.

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.

In the embodiment shown in FIG. 7, since the inner casing 5 does not have an air bleed hole 10, a portion 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 housing space S3, the generator housing 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.

With 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 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 when the bleed air is mixed with the main flow introduced into the turbine rotor blade 4.

(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. Although the first throttling portion A1 and the second throttling portion A2 are depicted in Fig. 8, 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 has the thrust disk portion 22, 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 and the inner surface 58 of the inner casing 5 that faces the outer circumferential surface 221 with a gap therebetween.

According to the above configuration, by providing the first throttling portion A1, the thrust disk portion 22 is pushed from the other side to the one side by the pressure difference generated between the one side and the other side in the axial direction of the first throttling portion A1 of the bearing housing space S3, thereby reducing the thrust force on the rotating shaft 2. By providing the first throttling portion A1 upstream of the generator housing 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.

In some embodiments of the power generation turbine 1, 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 and the inner surface (inner peripheral surface) 56A of the inner casing 5 that faces the outer peripheral surface 33 with a gap therebetween.

In order for the rotor 31 of the generator 3 to rotate 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.

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 the 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 peripheral gap S22), thereby reducing the thrust force on 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.

In some embodiments, as shown in Figures 1, 2, 6 and 7, the inner casing 5 of the power generation 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 the 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, further than 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 of the inner circumferential gap S21. The other side space S24 is formed by the rotor 31 and the stator support part 51. The inner opening 542 of each of the plurality of through holes 54 described above is connected to the other side space S24.

With the above configuration, the working fluid (bleed air) introduced into the generator housing space S2 passes through the outer peripheral gap S22, the one-side space S23, the inner peripheral 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 housing space S2.

(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.

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.

(Heat medium circulation line)
The heat medium circulation line 101 is configured to circulate a heat medium having a lower freezing point than water. Hereinafter, liquefied natural gas (LNG) will be used as a specific example of a liquefied gas, and propane will be 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.

(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.

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.

Then, 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, and is supplied as fuel to an engine (not shown) installed downstream of the condenser 103.

(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.

The cold/heat pump 105 may be of any type as long as it can boost the pressure of the heat medium. For example, a turbo pump (centrifugal pump, mixed flow pump, axial flow pump, etc.), a positive displacement pump (reciprocating pump, rotary pump), a special pump (submersible motor pump), or other type may be appropriately selected according to the embodiment.

(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.

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

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. The heating fluid is cooled by heat exchange inside the evaporator 106, flows through the heat medium heating side pipe 106B, and then flows again through the heating fluid supply line 104, and is discharged outside the power generation system 100.

The above-mentioned "heating fluid" may be any fluid that heats the heat medium circulating in 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.

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 with the gaseous heat medium generated in the evaporator 106. The gaseous heat medium that drives the power generation turbine 1 flows through the heat medium circulation line 101 toward the condenser 103 described above, which is installed downstream of the power generation turbine 1.

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 circulating through the heat medium circulation line 101 and introduced into the power generation turbine 1 is at a relatively low temperature due to the recovery of 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.

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 can be 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.

This disclosure is not limited to the above-described embodiments, but also includes modifications to 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 power generating 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, 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).

According to the configuration of 1) above, by making the generator (3) provided on the other side of the rotating shaft (2) an outer rotor type, a higher power density can be achieved and the radial size of the generator (3) and the generator housing space (S2) can be reduced compared to when it is an inner rotor type. This allows the working fluid flow path (S4) formed on the outer periphery of the generator housing space (S2) to be positioned relatively radially inward, thereby preventing the power generation turbine (1) from becoming too large.

Furthermore, according to the configuration of 1) above, a portion of the working fluid flowing through the working fluid passage (S4) can be bled into the generator housing space (S2) via the first gap (S1) and the through hole (54), and can be discharged from the generator housing space (S2) after cooling the generator (3). Since the generator (3) can be cooled by such a simple structure, the complexity of the power generation turbine (1) can be suppressed.

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 formed between the generator accommodating space (S2) and the first gap (S1) in the axial direction, and a bearing accommodating space (S3) is formed which is connected to the generator accommodating space (S2) and the first gap (S1) and accommodates the rotating shaft (2) and the at least one magnetic bearing (7).

According to the configuration of 2) above, the generator housing space (S2) and the first gap (S1) can allow the working fluid (bleed air) to flow through the bearing housing space (S3), which houses the magnetic bearing (7) that does not require lubrication. In this case, there is no need to provide a separate flow path for the working fluid to flow between the generator housing space (S2) and the first gap (S1), which prevents the power generation turbine (1) from becoming larger and more complicated.

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

According to the configuration of 3) above, a portion of the working fluid that has passed through the turbine rotor blades (4) can be made to flow into the generator housing space (S2) through the first gap (S1). The working fluid that flows into the generator housing space (S2) expands and has a lowered temperature as it passes through the turbine rotor blades (4), so the generator (3) can be effectively cooled by the working fluid.

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

According to the configuration of 4) above, the generator (3) can be cooled by allowing a portion of the working fluid before being introduced into the turbine rotor blades (4) to flow into the generator housing space (S2) through the through hole (54). Then, by mixing the working fluid with increased enthalpy as a result of recovering thermal energy from the generator (3) with the working fluid 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.

5) In some embodiments, the power generating turbine (1) according to 3) above,
The rotor blade (4) is provided with a resistor (12) for generating a pressure loss, the resistor (12) being provided on one side of the at least one turbine blade (4) in the axial direction in the working fluid flow path (S4), and for making 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).

According to the configuration of 5) above, a resistor (12) is provided in the working fluid flow path (S4) and the pressure of the working fluid flow path between the resistor (12) and the turbine rotor blades (4) is made higher than the pressure in the bearing housing space (S3), so that 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, since there is no need to separately provide a fan or the like for circulating the working fluid in the generator housing space (S2), it is possible to suppress an increase in the number of pieces of equipment in the power generation turbine (1) and also suppress an increase in the power consumption of the power generation turbine (1).

6) In some embodiments, the power generating turbine (1) according to 4) above,
the disk portion (43) of the at least one turbine 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.

According to the configuration of 6) above, the working fluid (bleed air) guided from the bearing housing space (S3) to the first gap (S1) passes through the first balance hole (48) and is mixed with the working fluid (main flow) that has passed through the turbine rotor blade (4) in which the first balance hole (48) is formed, downstream of the turbine rotor blade (4) in which the first balance hole (48) is formed in the flow direction of the working fluid. 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 housing 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).

7) In some embodiments, the power generating turbine (1) according to 6) above,
The at least one turbine blade (4) comprises:
A 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).

According to the configuration of 7) above, the working fluid (bleed air) that has passed through the first balance hole (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 hole (49) further outward in the radial direction of the rotating shaft (2) than the first balance hole (48), the working fluid (bleed air) that has passed through the first balance hole (48) is more likely to flow into the second balance hole (49). By passing the working fluid (bleed air) guided from the bearing accommodation space (S3) to the first gap (S1) through not only the first balance hole (48) but also the second balance hole (49), the pressure loss when the bleed air and the main flow are mixed can be further reduced.

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

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

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 bleed hole (10) having an outer opening (10A) formed in an outer peripheral surface (53) which 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) which forms the bearing accommodating space (S3) on the other side in the axial direction relative to the other-side thrust bearing (72).

According to the configuration of 9) above, a portion of the working fluid introduced into the turbine rotor blades (4) can be made to flow into the generator housing 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 housing space (S2) from the other side to the one side in the axial direction, thereby reducing the thrust force applied to the rotating shaft (2).

10) In some embodiments, the power generating turbine (1) according to 9) above,
The at least one turbine blade (4) comprises:
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:
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),
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).

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) with increased enthalpy as a result of 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), thereby increasing the power recovery in the turbine rotor blades (4) and increasing the output of the power generating turbine (1).

Furthermore, according to the configuration of 10) 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 when the bleed air is mixed with the main flow introduced into the turbine rotor blade (4).

11) In some embodiments, the power generating turbine (1) according to 8) above,
The at least one turbine blade (4) comprises:
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:
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),
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).

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 when the bleed air is mixed with the main flow introduced into the turbine rotor blade (4).

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 section (A1) that narrows the flow path of the working fluid is provided between an outer peripheral surface (221) of the thrust disk section (22) and an inner surface (58) of the inner casing (5) that faces the outer peripheral surface (221) of the thrust disk section (22) with a gap therebetween.

According to the configuration of 12) above, by providing the first throttling portion (A1), the thrust disk portion (22) is pushed from the other side to the one side by the pressure difference generated between the one side and the other side in the axial direction of the first throttling portion (A1) of the bearing accommodation space (S3), thereby reducing the thrust force on the rotating shaft (2). By providing the first throttling portion (A1) upstream of the generator accommodation 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).

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 the outer peripheral surface (33) of the rotor (31) and the inner surface (56A) of the inner casing (5) that faces the outer peripheral surface (33) of the rotor (31) with a gap therebetween.

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 the 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 peripheral 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 when the first throttling portion (A1) is provided, thereby preventing the power generation turbine (1) from becoming larger.

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).

According to the configuration of 14) above, the working fluid (bleed air) introduced into the generator housing space (S2) passes through the outer circumferential gap (S22), the one-side space (S23), the inner circumferential 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 housing space (S2).

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

According to the configuration of 15) above, 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 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.

Reference Signs List 1 Power generation turbine 2 Rotating shaft 3 Generator 4 Turbine rotor blade 5 Inner casing 6 Outer casing 7 Bearing 9 Extraction line 10 Extraction hole 11 Casing support portion 21 One side end portion 22 Thrust disk portion 31 Rotor 32 Stator 41 One side rotor blade 42 Other side rotor blade 43, 45 Disk portion 44, 46 Blade portion 51 Stator support portion 52 Opposing surface 53 Outer peripheral surface 54 Through hole 55 Outer surface 56 Inner surface 61 Inner peripheral surface 71, 72 Thrust bearing 73, 74 Journal bearing 81, 81A One side stator blade 82, 82A Other side stator blade 83, 83A, 84A Blade portion 84, 85A Inner stator blade support portion 311 Magnet support portion 312 Permanent magnet 313 Radial extension portion 314 Axial extension portion 315 Inclined portion 321 Stationary coil portion 541 Outer opening 542 Inner opening CA Central axis S1 First gap S2 Generator housing space S3 Bearing housing space S4 Working fluid flow path S21 Inner circumference side gap S22 Outer circumference side gap S23 One side space S24 Other side space S41 Annular flow path S42 One side columnar flow path S43 Other side columnar flow path

Claims (15)

1. 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, the inner casing 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 provided with at least one through hole having an outer opening formed on an outer surface that forms the working fluid flow path and an inner opening formed on an inner surface that forms the generator accommodating space;
   Power generating turbine.
2. and at least one magnetic bearing disposed axially between the generator and the at least one turbine blade and configured to rotatably support the rotating shaft;
   The inner casing has a bearing accommodating space between the generator accommodating space and the first gap in the axial direction, the bearing accommodating space being connected to the generator accommodating space and the first gap and accommodating the rotating shaft and the at least one magnetic bearing.
   2. The power generating turbine of claim 1.
3. The working fluid is configured to flow through the working fluid flow path from the other side to the one side in the axial direction.
   3. The power generating turbine of claim 2.
4. The working fluid is configured to flow through the working fluid flow path from the one side to the other side in the axial direction.
   3. The power generating turbine of claim 2.
5. the turbine rotor blade further includes a resistor for generating a pressure loss, the resistor being provided in the working fluid flow path on the one side in the axial direction of the at least one turbine rotor blade, the resistor making a pressure in the working fluid flow path between the resistor and the at least one turbine rotor blade greater than a pressure in the bearing accommodating space,
   4. The power generating turbine of claim 3.
6. the disk portion of the at least one turbine blade facing the opposing surface of the inner casing across the first gap has a first balance hole penetrating therethrough in the axial direction,
   The first balance hole is configured so that the working fluid guided from the bearing accommodating space to the first gap flows into the first balance hole.
   5. The power generating turbine of claim 4.
7. The at least one turbine blade comprises:
   one rotor blade having the first balance hole;
   a second rotor blade provided on the second side in the axial direction relative to the first rotor blade,
   the disk portion of the other rotor blade has a second balance hole penetrating therethrough in the axial direction,
   The second balance hole is formed on the outer side of the first balance hole in the radial direction of the rotating shaft, and is configured so that the working fluid that has passed through the first balance hole flows into the second balance hole.
   7. The power generating turbine of claim 6.
8. a bleed line having one end connected to the outer opening of the at least one through hole;
   5. The power generating turbine of claim 4.
9. the rotating shaft has a thrust disk portion protruding radially outward of the rotating shaft in the bearing accommodating space,
   the at least one magnetic bearing includes a second-side thrust bearing that is disposed on the second side of the thrust disk portion in the axial direction of the rotating shaft and faces the thrust disk portion with a gap therebetween;
   the inner casing is provided with at least one bleed hole having an outer opening formed in an outer peripheral surface that forms the working fluid flow path on the outer peripheral side of the bearing accommodating space, and an inner opening formed in an inner surface that forms the bearing accommodating space on the other side in the axial direction relative to the other-side thrust bearing,
   9. The power generating turbine of claim 8.
10. The at least one turbine blade comprises:
    One rotor blade;
    a second rotor blade provided on the second side in the axial direction relative to the first rotor blade,
    The power generating turbine comprises:
    a one-side stator vane arranged on the one side in the axial direction relative to the one-side rotor blade and the first gap,
    the other end of the extraction line is connected to either a first space between the one-side stator vane and the one-side rotor blade in the working fluid flow path, or a second space on the other side of the other-side rotor blade.
    10. The power generating turbine of claim 9.
11. The at least one turbine blade comprises:
    One rotor blade;
    a second rotor blade provided on the second side in the axial direction relative to the first rotor blade,
    The power generating turbine comprises:
    a one-side stator vane arranged on the one side in the axial direction relative to the one-side rotor 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 rotor blade in the working fluid flow path.
    9. The power generating turbine of claim 8.
12. the rotating shaft has a thrust disk portion protruding radially outward of the rotating shaft in the bearing accommodating space,
    a first throttle portion for narrowing a flow path of the working fluid is provided between an outer circumferential surface of the thrust disk portion and an inner surface of the inner casing facing the outer circumferential surface of the thrust disk portion with a gap therebetween;
    12. A power generating turbine as claimed in any one of claims 8 to 11.
13. a second throttle portion for narrowing a flow path of the working fluid is provided between an outer circumferential surface of the rotor and an inner surface of the inner casing that faces the outer circumferential surface of the rotor with a gap therebetween;
    12. A power generating turbine as claimed in any one of claims 8 to 11.
14. the inner casing includes a stator support portion that supports the stator from an inner circumferential side,
    The generator accommodating space is
    an outer circumferential gap formed between an outer circumferential surface of the rotor and an inner surface of the inner casing that faces the outer circumferential surface of the rotor with a gap on the outer circumferential side;
    an inner peripheral gap formed between the rotor and the stator;
    a one-side space connected to the outer circumferential side gap and the inner circumferential side gap on the one side in the axial direction relative to the inner circumferential side gap;
    a second-side space connected to the inner-periphery-side gap at a position on the other side in the axial direction relative to the inner-periphery-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.
    12. A power generating turbine as claimed in any preceding claim.
15. The power generation turbine according to claim 1 , wherein the power generation turbine is provided in a heat medium circulation line configured to circulate a heat medium for heating a liquefied gas.

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