Nano-water droplet generating device and steam turbine system

Abstract

To provide a nano-water droplet generating device and a steam turbine system, which can suppress an overcooling loss in a steam turbine.SOLUTION: A nano-water droplet generating device is for supplying a mixed fluid containing nano-water droplets and a gas-phase fluid to the main steam flow passage of a steam turbine. The device comprises: a chamber that is formed with an introduction port for introducing the gas-phase fluid, a mixing space for mixing the nano-water droplets and the gas-phase fluid, and a discharge port for discharging the mixed fluid; a liquid tank configured to store liquid below the mixing space; and a vibrator unit including at least one vibrator that is configured to vibrate while being submerged in the liquid in the liquid tank, thereby generating a mist containing nano-water droplets in the mixing space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a nano-water droplet generating device and a steam turbine system. [Background technology]

[0002] Conventionally, steam turbine systems have been known that supply fluid containing fine particles to the main steam flow path in order to reduce subcooling loss in the steam turbine. The subcooling loss is reduced because the water molecules that make up the main steam can condense using the fine particles as nuclei in the main steam flow path. For example, Patent Document 1 cites nano-water droplets with a median diameter of approximately 0.05 μm as an example of the fine particles, and wet steam containing these nano-water droplets is supplied to the main steam flow path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-151056 Summary of the Invention [Problem to be solved by the invention]

[0004] The above patent document does not disclose a specific configuration for generating nanodroplets.

[0005] An object of the present disclosure is to provide a nano-water droplet generating device and a steam turbine system that can suppress subcooling loss in a steam turbine. [Means for solving the problem]

[0006] According to at least one embodiment of the present disclosure, a nano-water droplet generating device includes: 1. A nano-water droplet generating apparatus for supplying a mixed fluid including nano-water droplets and a gas-phase fluid to a main steam path of a steam turbine, comprising: a chamber in which an inlet for introducing the gas-phase fluid, a mixing space for mixing the nanodroplets and the gas-phase fluid, and an outlet for discharging the mixed fluid are formed; a liquid tank configured to store a liquid below the mixing space; a vibrator unit including at least one vibrator configured to vibrate while submerged in the liquid in the liquid tank to generate a mist containing the nanodroplets in the mixing space; Equipped with.

[0007] A steam turbine system according to at least one embodiment of the present disclosure includes: The nano-water droplet generating device, the steam turbine having the main steam flow path into which the mixed fluid flows; Equipped with. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a nano-water droplet generating device and a steam turbine system that can suppress supercooling loss in a steam turbine. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an apparatus for generating nano-water droplets according to an embodiment. [Figure 2] 1 is a schematic enlarged partial view of a nano-water droplet generating device according to an embodiment. [Figure 3] FIG. 2 is a schematic plan view of a vibrator and a first partition plate according to one embodiment. [Figure 4] FIG. 4 is a schematic plan view of a second partition plate according to one embodiment. [Figure 5] FIG. 2 is a schematic diagram of a transducer unit according to an embodiment. [Figure 6] FIG. 2 is a schematic view of a liquid tank partition according to an embodiment. [Figure 7] 1 is a schematic diagram of a steam turbine system according to a first embodiment. [Figure 8] FIG. 4 is a schematic diagram of a steam turbine system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several 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 embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state 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. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," or "have" one element are not exclusive expressions that exclude the presence of other elements. Note that the same components will be denoted by the same reference numerals and the description thereof will be omitted.

[0011] <Outline of Nano Water Droplet Generator 5> 1 is a schematic diagram of a nano-water droplet generating device 5 according to an embodiment of the present disclosure. The nano-water droplet generating device 5 is a device for supplying a mixed fluid containing nano-water droplets and a gas-phase fluid to the main steam flow path 4 of a steam turbine 3 (see FIG. 7). As the main steam (working steam) of the steam turbine 3 flows downstream through the main steam flow path 4, the water molecules constituting the main steam grow into water droplets using the nano-water droplets contained in the mixed fluid as nuclei. This reduces the subcooling loss of the steam turbine 3.

[0012] The nano-water droplet generating device 5 includes a chamber 30, a liquid tank 40, and a vibrator unit 50. In the following description, the first horizontal direction may be referred to as the "first horizontal direction" (see FIG. 1), and the second horizontal direction perpendicular to the first horizontal direction may be referred to as the "second horizontal direction" (see FIG. 3).

[0013] The chamber 30 is formed with an inlet 31 for introducing a gas-phase fluid, which may be, for example, steam or air, a mixing space 35 for mixing the nanodroplets and the gas-phase fluid, and an outlet 39 for discharging the mixed fluid. The inlet 31 and the outlet 39 are holes that penetrate a pair of sidewalls 87, which are components of the chamber 30, and the pair of sidewalls 87 face each other in a first horizontal direction with the mixing space 35 between them. The inlet 31 is located on one side in the first horizontal direction, and the outlet 39 is located on the other side in the first horizontal direction. The flow of the gas-phase fluid introduced at the inlet 31 is indicated by arrow F1, and the flow of the mixed fluid discharged from the outlet 39 is indicated by arrow F2.

[0014] The liquid tank 40 is configured to store the liquid Lq below the mixing space 35 in the chamber 30. While the liquid Lq is, for example, pure water, the present disclosure is not limited thereto, and water containing some kind of solvent or fine particles may also be used as the liquid Lq. The upper part of the liquid tank 40 in this embodiment is integrally formed with the lower part of the chamber 30, and a liquid tank space 45 formed inside the liquid tank 40 communicates with the mixing space 35 of the chamber 30. In some embodiments, the liquid tank space 45 may be divided into a settling space 451 and a drainage space 452 by a liquid tank partition 46 (details will be described later). The liquid tank 40 and the chamber 30 may also form a single sealed container.

[0015] The oscillator unit 50 includes at least one oscillator 55. The oscillator 55, which may be in the form of a plate, is configured to vibrate while submerged in the liquid Lq in the liquid tank 40, thereby generating a mist Ms containing nano-droplets in the mixing space 35. As a more specific example, the oscillator 55 applies ultrasonic vibrations to the liquid Lq, thereby forming a liquid column 9 that extends upward from the liquid surface Ls of the liquid Lq to the mixing space 35. In this example, the mist Ms is generated from the liquid column 9. Note that, by way of example only, the particle size of the nano-droplets contained in the mist Ms is 500 nm or less. The particle size is determined by the arithmetic mean D of the particle size of the droplets. 10 It is expressed by particle size.

[0016] According to the above configuration, mist Ms containing nano-water droplets generated by the vibration of oscillator 55 is mixed with gas-phase fluid introduced from inlet 31 in mixing space 35. As a result, a mixed fluid containing nano-water droplets and gas-phase fluid is generated, and flows into main steam flow path 4 of steam turbine 3 (see FIG. 7) via outlet 39. Supercooled water molecules that make up the main steam flowing through main steam flow path 4 can grow into water droplets using nano-water droplets as nuclei. Thus, nano-water droplet generating device 5 that can reduce supercooling loss in steam turbine 3 is realized.

[0017] <Details of the configuration of the nano-water droplet generating device 5> The detailed configuration of the nano-water droplet generating device 5 will be described with reference to Figures 2 to 4. Figure 2 is a schematic partial enlarged view of the nano-water droplet generating device 5 according to one embodiment of the present disclosure. The nano-water droplet generating device 5 includes a first partition plate 10 and a second partition plate 20, each extending to separate a liquid tank space 45 and a mixing space 35. The first partition plate 10 and the second partition plate 20 extend in a first horizontal direction and a second horizontal direction. The second partition plate 20 faces the first partition plate 10 from above, with a gap therebetween.

[0018] The first partition plate 10 includes a first main body portion 19 and a first opening 11 formed in the first main body portion 19, and the second partition plate 20 includes a second main body portion 28 and a second opening 22 formed in the second main body portion 28. Both the first opening 11 and the second opening 22 are holes that are open in the vertical direction. The liquid tank space 45 and the mixing space 35 communicate with each other via the first opening 11 and the second opening 22. In addition, the liquid column 9 generated by the vibrator 55 passes through the first opening 11 and the second opening 22.

[0019] A plurality of first drain holes (not shown) are further formed in the first main body portion 19 of the first partition plate 10, and similarly, a plurality of second drain holes (not shown) are further formed in the second main body portion 28 of the second partition plate 20. After the liquid Lq constituting the liquid column 9 in the mixing space 35 reaches a predetermined height, it falls toward the liquid tank 40. The liquid Lq first falls to the second partition plate 20. The liquid Lq on the second partition plate 20 falls from the second drain holes to the first partition plate 10. The liquid Lq on the first partition plate 10 falls from the first drain holes to the liquid level Ls.

[0020] In some embodiments, first body portion 19 is preferably slightly inclined with respect to the first horizontal direction and the second horizontal direction so that at least one first drain hole is located below first opening hole 11. Similarly, second body portion 28 is preferably slightly inclined with respect to the first horizontal direction and the second horizontal direction so that at least one second drain hole is located below second opening hole 22. This makes it possible to prevent liquid Lq from accumulating without falling in each of first partition plate 10 and second partition plate 20.

[0021] In this embodiment, a plurality of oscillators 55 are arranged from one side to the other in the first horizontal direction, and a plurality of first opening holes 11 and a plurality of second opening holes 22 are arranged in the same number as the oscillators 55. Each oscillator 55 is plate-shaped and inclined with respect to the first horizontal direction, and in the example of Fig. 2, it is inclined downward as it approaches one side in the first horizontal direction. As a result, the liquid column 9 generated by the vibration of the oscillator 55 is inclined with respect to the vertical direction, and extends toward one side as it approaches the top.

[0022] 3 is a schematic plan view of a vibrator 55 and a first partition plate 10 according to an embodiment of the present disclosure. The vibrator 55 in this example has two rows of vibrators 55 aligned from one side to the other. A plurality of first opening holes 11 and a plurality of second opening holes 22 (see FIG. 3) are arranged corresponding to the plurality of vibrators 55 aligned in the two rows.

[0023] In a plan view, the center C1 of the first opening hole 11 is shifted from the center Cv of the transducer 55 corresponding to the first opening hole 11. More specifically, the center C1 is located on one side in the first horizontal direction with respect to the center Cv.

[0024] 4 is a schematic plan view of a second partition plate 20 according to an embodiment of the present disclosure. In the drawing, the first openings 11 of the first partition plate 10 are indicated by two-dot chain lines. In plan view, the centers C2 of the second openings 22 are offset from the centers C1 of the first openings 11 corresponding to the second openings 22. More specifically, the centers C2 are located on one side of the centers C1 in the first horizontal direction.

[0025] As described above, the centers Cv, C1, and C2 are offset from one another in plan view, which allows the liquid column 9, which extends from the liquid level Ls at an angle relative to the vertical direction, to pass through the first opening 11 and the second opening 22 without hitting the first main body portion 19 and the second main body portion 28 (see FIG. 2).

[0026] The technical advantages obtained from the nano-water droplet generating device 5 described above will now be explained. Dimension D in FIG. 2 indicates the depth at which the oscillator 55 is disposed in the liquid Lq. According to the findings of the inventors of the present application, if the oscillator 55 is disposed too deep, most of the vibrations of the oscillator 55 are absorbed by the liquid Lq, and mist Ms containing nano-water droplets is not generated. Conversely, if the oscillator 55 is disposed too shallow, there is a risk that the vibrations of the oscillator 55 will damage the oscillator unit 50. Therefore, it is preferable that the depth at which the oscillator 55 is disposed in the liquid Lq be a value within a predetermined range.

[0027] In this regard, according to the above-described configuration, the first partition plate 10 extends in the first horizontal direction so as to separate the liquid tank space 45 and the mixing space 35, thereby preventing the liquid Lq constituting the liquid column 9 in the mixing space 35 from directly falling onto the liquid level Ls. The force exerted by the falling liquid Lq on the liquid level Ls is alleviated, thereby preventing rippling of the liquid level Ls. Alternatively, if the gas-phase fluid introduced through the inlet 31 is, for example, a compressed gas-phase fluid delivered by the compressor 13 (see FIG. 7 ), the first partition plate 10 can prevent the flow of the compressed gas-phase fluid in the mixing space 35 from affecting the liquid level Ls. This prevents rippling of the liquid level Ls. The suppression of rippling of the liquid level Ls prevents fluctuations in the depth of the oscillator 55 in the liquid Lq. Therefore, the oscillator 55 can stably generate a mist Ms containing nano-water droplets, and the nano-water droplets are stably supplied to the main steam flow path 4.

[0028] 2, the liquid column 9, which extends upward from the liquid level Ls so as to be inclined relative to the vertical direction, reaches a predetermined height and then falls toward the liquid tank space 45. Here, because the center C1 of the first opening hole 11 is offset from the center Cv of the oscillator 55 in a plan view, the liquid Lq constituting the liquid column 9 can fall onto the first main body portion 19 of the first partition plate 10. Since the liquid Lq is prevented from falling directly onto the liquid level Ls, rippling of the liquid level Ls can be further prevented.

[0029] Furthermore, with a configuration in which a plurality of oscillators 55 are arranged from one side to the other in the first horizontal direction and a plurality of first opening holes 11 corresponding to the respective oscillators 55 are arranged, mist Ms is generated over a certain range in the flow direction of the gas-phase fluid in the mixing space 35. As the gas-phase fluid flows from the inlet 31 toward the outlet 39, the gas-phase fluid and the nano-water droplets can be well mixed. This allows a stable supply of nano-water droplets in an amount necessary to reduce supercooling loss into the main steam flow path 4.

[0030] Furthermore, in the above configuration, the second partition plate 20 protects the liquid surface Ls in addition to the first partition plate 10, thereby further suppressing rippling of the liquid surface Ls. Furthermore, because the center C2 of the second opening hole 22 is offset to one side from the center C1 of the first opening hole 11 in a plan view, the liquid Lq of the liquid column 9 that passes through the first opening hole 11 and the second opening hole 22 and reaches a predetermined height first falls into the second main body portion 28 of the second partition plate 20, and then falls into the first main body portion 19 of the first partition plate 10. This further prevents the liquid Lq from falling directly onto the liquid surface Ls.

[0031] Returning to Figure 2, we will continue to explain the configuration of the nanodroplet generating device 5 in detail. The liquid tank 40 includes a bottom wall portion 44, which has an inlet hole 41 for the liquid Lq and an outlet hole 49 for the liquid Lq formed in it. One end of a supply pipe 71 for the liquid Lq is disposed in the inlet hole 41, and one end of a drain pipe 79 for the liquid Lq is disposed in the outlet hole 49. In this example, while the vibrator 55 is vibrating, the liquid Lq is supplied from the supply pipe 71 to the inlet hole 41, and the liquid Lq is discharged from the outlet hole 49 to the drain pipe 79.

[0032] According to the above configuration, while the oscillator 55 is vibrating, it is possible to cause the liquid Lq to continuously flow in and out of the liquid tank 40, and the oscillator 55 can vibrate within the flowing liquid Lq. This prevents the temperature of the oscillator 55 from exceeding the upper limit temperature, allowing the oscillator 55 to stably generate the mist Ms. More specifically, if the oscillator 55 is made of a magnetic material, the oscillator 55 cannot vibrate if its temperature exceeds the Curie temperature. In this regard, in the present example, because the oscillator 55 vibrates within the flowing liquid Lq, the temperature of the oscillator 55 can be kept below the Curie temperature, allowing the oscillator 55 to stably generate the mist Ms.

[0033] <Transducer unit 50> 5 is a schematic diagram of a vibrator unit 50 according to one embodiment of the present disclosure. The vibrator unit 50 further includes a mounting base 57 on which a vibrator 55 is mounted, and a plurality of legs 58 protruding downward from the mounting base 57. The mounting base 57 extends perpendicular to the first horizontal direction and the second horizontal direction, and is formed of a thermoplastic resin such as polycarbonate.

[0034] In this embodiment, the amount of protrusion of each leg 58 (dimension Lp in FIG. 3) is adjustable. More specifically, a plurality of screw holes 59 are formed in the installation base 57, and a portion of each leg 58 is screwed into each screw hole 59. The amount of protrusion of the leg 58 is adjusted by rotating the leg 58. Note that the screw holes 59 illustrated in FIG. 3 are open in the vertical direction, and the leg 58 can be rotated by inserting a screwdriver into the screw hole 59 from above.

[0035] According to the above configuration, multiple legs 58 can be arranged on the bottom wall 44 (see FIG. 2) of the liquid tank 40, so that the vibrator 55 can be arranged at a predetermined depth range in the liquid Lq. Therefore, the vibrator 55 can stably generate a mist Ms containing nano-droplets. Furthermore, because the protrusion amount of the legs 58 can be adjusted, the depth of the vibrator 55 can be set to a desired depth. This allows the vibrator 55 to generate the mist Ms even more stably.

[0036] 2, the inlet hole 41 of the liquid tank 40 is formed in the bottom wall portion 44 below the installation base 57. In other words, the inlet hole 41 communicates with the liquid tank space 45 below the installation base 57. The inlet hole 41 is arranged so as to overlap with the installation base 57 in a plan view.

[0037] According to the above configuration, the liquid Lq flowing in from the inlet 41 flows in a manner that bypasses the installation base 57 before reaching the liquid level Ls (arrow Q in FIG. 2). The momentum of the flow of the liquid Lq weakens during the bypass process. Therefore, rippling of the liquid level Ls can be suppressed compared to when the liquid Lq that passes through the inlet 41 reaches the liquid level Ls without bypassing it. Note that, in order to facilitate bypassing of the liquid Lq, it is preferable that the end of the installation base 57 abuts against the inner wall of the liquid vat 40 in the second horizontal direction.

[0038] <Liquid tank partition 46> As shown in FIG. 2, the liquid tank 40 further includes a liquid tank partition 46 that stands upright from the bottom wall 44. The liquid tank partition 46 is arranged to divide the liquid tank space 45 within the liquid tank 40 into a settling space 451 and a drainage space 452. The settling space 451 is a space in which the transducer unit 50 is submerged in the liquid Lq, and the drainage space 452 is a space in which the liquid Lq that overflows the liquid tank partition 46 flows out through the outflow holes 49. The liquid level in the settling space 451 is higher than the liquid level in the drainage space 452. In this embodiment, the vertical length of the liquid tank partition 46 (dimension Lp in FIG. 2) is adjustable. The specific configuration is as follows.

[0039] FIG. 6 is a schematic diagram of a liquid tank divider 46 according to one embodiment of the present disclosure. The liquid tank divider 46 includes a fixed divider plate 461 fixed to the bottom wall 44 (see FIG. 2), a movable divider plate 462 protruding above the fixed divider plate 461, and a fastening member 463. The fastening member 463, which may be a bolt, is inserted into a vertically elongated hole 462a formed in the movable divider plate 462 and is threaded into a screw hole 461a formed in the fixed divider plate 461. The operator loosens the fastening member 463 and then slides the movable divider plate 462 relative to the fixed divider plate 461. After adjusting the height of the movable divider plate 462, the fastening member 463 is retightened, completing the length adjustment of the liquid tank divider 46.

[0040] According to the above configuration, the upper end of the movable partition plate 462 is approximately the same height as the liquid level Ls in the settling space 451. By setting the liquid tank partition 46 to a predetermined vertical length, it is possible to set the liquid level Ls in the settling space 451 to a desired height. This allows the vibrator 55 to be positioned at a desired depth in the liquid Lq. Furthermore, by making the vertical length of the liquid tank partition 46 adjustable, the height of the liquid level Ls can be adjusted. This makes it even easier to set the depth of the vibrator 55 to a desired value.

[0041] <Steam Turbine System 1> 7 is a schematic diagram of a steam turbine system 1A (1) according to a first embodiment. The steam turbine system 1A includes a nano-water droplet generation device 5 and a steam turbine 3 to which a mixed fluid discharged from the nano-water droplet generation device 5 is supplied. The steam turbine 3 includes a rotor 2, a plurality of moving blades 6 fixed to the outer peripheral surface of the rotor 2, and an inner casing (not shown) that houses the rotor 2 and the plurality of moving blades 6. A plurality of stator vanes 7 are fixed to the inner peripheral side of the inner casing (not shown). The inner casing also defines a main steam flow path 4 for main steam (working steam) supplied to the steam turbine 3 from a boiler (not shown).

[0042] In this example, a plurality of moving blades 6 arranged in the circumferential direction on the outer peripheral surface of the rotor 2 and a plurality of stator vanes 7 arranged in the circumferential direction are alternately arranged along the axial direction of the rotor 2. A plurality of stator vanes 7 and a plurality of moving blades 6 adjacent to each other in the axial direction constitute a turbine stage 15. In a single turbine stage 15, the plurality of moving blades 6 are located downstream of the plurality of stator vanes 7 in the flow direction of the main steam. The steam turbine 3 in this example has a plurality of turbine stages 15 arranged therein.

[0043] In the steam turbine 3 having the above configuration, the main steam flowing through the main steam flow path 4 expands and increases in speed as it passes through the stationary blades 7, and performs work on the rotor blades 6. This rotates the rotor 2. The steam (wet steam) that has completed its work and is discharged from the steam turbine 3 is condensed in a condenser 8, which is a component of the steam turbine system 1, and then returned to the boiler.

[0044] In the nano-water droplet generating device 5 illustrated in FIG. 7, a liquid tank 40 and a chamber 30 cooperate to form a sealed container (note that the first partition plate 10 and the second partition plate 20 are not shown in the figure). Gas delivered by a compressor 13 is supplied as a gas-phase fluid to an inlet 31 of the sealed container. The gas compressed by the compressor 13 may be superheated steam generated by a boiler. Inside the chamber 30 that constitutes the sealed container, the nano-water droplets mix with the gas-phase fluid to generate a mixed fluid. The high-pressure mixed fluid is supplied to the inlet 3a of a steam turbine 3.

[0045] 7 includes a supply tank 101 that stores the liquid Lq to be supplied, and a drain tank 102 that stores the liquid Lq discharged from the chamber 30. A supply pipe 71 connects the supply tank 101 to the liquid tank 40, and a drain pipe 79 connects the liquid tank 40 to the drain tank 102. In addition, a supply pump 103 is disposed in the supply pipe 71 to supply the liquid Lq in the supply tank 101 to the liquid tank 40.

[0046] Furthermore, the nanodroplet generating device 5 includes a flow regulation valve 88 disposed in each of the supply pipe 71 and the drain pipe 79, a temperature sensor 89 for measuring the temperature of the liquid Lq in the liquid tank 40, and a controller 90. In this example, the temperature sensor 89 is configured to measure the temperature of the liquid Lq in the settling space 451. The controller 90 is configured to feedback-control the opening of each flow regulation valve 88 so that the temperature measured by the temperature sensor 89 falls within an allowable range. As a more specific example, when the temperature measured by the temperature sensor 89 exceeds a target temperature, the controller 90 sends a command to each flow regulation valve 88 to increase the opening of the flow regulation valve 88.

[0047] According to the above configuration, the temperature of the liquid Lq in the settling space 451 of the liquid tank 40 can be kept within an allowable range, thereby preventing the temperature of the oscillator 55 from exceeding the upper limit temperature. Therefore, the oscillator 55 can stably generate the mist Ms, and the nano-water droplet generator 5 can stably supply nano-water droplets to the main steam flow path 4 of the steam turbine 3. Note that the flow adjustment valve 88 may be disposed only in either the supply pipe 71 or the drain pipe 79. Even in this case, the above technical advantages can be obtained.

[0048] Fig. 8 is a schematic diagram of a steam turbine system 1B(1) according to a second embodiment. In Fig. 8, the same components as those in the first embodiment are denoted by the same reference numerals as in Fig. 7, and the description thereof may be omitted or simplified below.

[0049] Atmospheric air is supplied to the inlet 31 of the nanodroplet generating device 5 shown in Fig. 8. A vacuum pump 105 is also provided to make the internal pressure of the drainage tank 102 a negative pressure lower than atmospheric pressure. When the vacuum pump 105 is operated, the liquid Lq in the supply tank 101 is supplied to the liquid tank 40 and then flows to the drainage tank 102.

[0050] In the steam turbine system 1B, the relatively low-pressure mixed fluid discharged from the nano-water droplet generator 5 is supplied between two adjacent turbine stages 15 in the main steam flow path 4. The supply position of the mixed fluid in the main steam flow path 4 is upstream of the supercooling region where the supercooling phenomenon of the main steam occurs.

[0051] In the second embodiment, the air contained in the mixed fluid flows into the main steam flow path 4. The air is degassed in the condenser 8, or degassed by a deaerator (not shown) arranged between the condenser 8 and the boiler.

[0052] <Other> The nanodroplet generating device 5 shown in Fig. 2 does not need to include the second partition plate 20. Even in this case, the liquid Lq constituting the liquid column 9 in the mixing space 35 falls onto the first partition plate 10, making it possible to protect the liquid level Ls of the liquid Lq in the liquid tank space 45. Furthermore, the liquid column 9 does not need to extend from the liquid level Ls to the mixing space 35. The mist Ms generated from the liquid column 9 located only in the liquid tank space 45 may enter the mixing space 35 via the first opening hole 11. Even in this case, a mixed fluid containing a gas-phase fluid and nanodroplets is generated in the mixing space 35.

[0053] The controller 90 is configured by a computer and includes a processor, a memory (storage medium), and an external communication interface. The processor may be a CPU, a GPU, an MPU, a DSP, or a combination thereof. The processor according to other embodiments may be implemented by an integrated circuit such as a PLD, an ASIC, an FPGA, or an MCU. The memory is configured to temporarily or non-temporarily store various data and may be implemented by at least one of a RAM, a ROM, or a flash memory. The processor executes various control processes according to instructions from a program loaded into the memory. The controller 90 may also be a DCS panel that constitutes one of multiple control panels that constitute the steam turbine system 1.

[0054] <Summary> The contents of the above-described embodiments can be understood, for example, as follows.

[0055] 1) The nano-water droplet generating device (5) according to at least one embodiment of the present disclosure comprises: A nano-water droplet generating device for supplying a mixed fluid including nano-water droplets and a gas-phase fluid to a main steam path (4) of a steam turbine (3), comprising: a chamber (30) in which an inlet (3a) for introducing the gas-phase fluid, a mixing space (35) for mixing the nanodroplets and the gas-phase fluid, and an outlet (39) for discharging the mixed fluid are formed; a liquid tank (40) configured to store a liquid (Lq) below the mixing space; a vibrator unit (50) including at least one vibrator (55) configured to vibrate while submerged in the liquid in the liquid tank, thereby generating a mist (Ms) containing the nanodroplets in the mixing space; Equipped with.

[0056] According to the configuration of 1) above, the mist generated by the vibration of the oscillator and the gas-phase fluid introduced through the inlet are mixed in the mixing space. This generates a mixed fluid containing nanodroplets and the gas-phase fluid, which flows into the main steam flow path of the steam turbine via the outlet. The supercooled water molecules that make up the main steam flowing through the main steam flow path can grow into water droplets using the nanodroplets as nuclei. This realizes a nanodroplet generating device that can reduce the supercooling loss of the steam turbine.

[0057] 2) In some embodiments, the nanodroplet generating device described in 1) above is The apparatus further includes a first partition plate (10) that extends along a first horizontal direction to separate the liquid tank space (45) in the liquid tank from the mixing space in the chamber, and that has a first opening hole (11) that is open in the vertical direction.

[0058] According to the configuration of 2) above, the liquid column or mist generated by the oscillator can pass through the first opening, generating mist in the mixing space. Furthermore, because the first partition plate extends in the first horizontal direction to separate the liquid tank space from the mixing space, the liquid surface in the liquid tank space is protected. This prevents the liquid surface from rippling, and prevents fluctuations in the depth of the oscillator in the liquid. Therefore, the oscillator can stably generate mist containing nanodroplets, and the nanodroplet generator can stably supply nanodroplets to the main steam flow path.

[0059] 3) In some embodiments, the nanodroplet generating device according to 2) above, the at least one oscillator is formed in a plate shape inclined with respect to the first horizontal direction, and is configured to generate a liquid column (9) passing through the first opening by applying vibration to the liquid, The center (C1) of the first opening hole is offset from the center (Cv) of the vibrator in a plan view.

[0060] According to the configuration 3) above, the liquid column generated by the vibration of the oscillator extends upward from the liquid surface at an incline relative to the vertical direction and passes through the first opening. When the liquid in the liquid column reaches a predetermined height, it falls toward the liquid tank space. Because the center of the first opening 11 is offset from the center of the oscillator, the liquid falls toward the first main body portion (19) of the first partition plate. This prevents the liquid that constitutes the liquid column from falling directly onto the liquid surface, further preventing the liquid surface from rippling.

[0061] 4) In some embodiments, the nano-water droplet generating device according to 3) above, the inlet is disposed on one side in the first horizontal direction, and the outlet is disposed on the other side in the first horizontal direction; The plurality of vibrators (55) as the at least one vibrator are arranged from the one side to the other side, The first partition plate has a plurality of first openings formed therein, each corresponding to one of the plurality of vibrators.

[0062] According to the configuration of 4) above, mist is generated in the mixing space over a certain range in the flow direction of the gas-phase fluid. As the gas-phase fluid flows from the inlet to the outlet, the gas-phase fluid and the nano-water droplets can be mixed well. This allows the amount of nano-water droplets required to reduce subcooling loss to be stably supplied to the main steam flow path.

[0063] 5) In some embodiments, the nanodroplet generating device according to any one of 2) to 4) above, The storage tank further includes a second partition plate (20) facing the first partition plate from above with a gap therebetween, The second partition plate is formed with a second opening (22) that opens in the vertical direction, The center (C2) of the second opening hole is offset from the center of the first opening hole in a plan view.

[0064] According to the above configuration 5), the second partition plate protects the liquid surface in addition to the first partition plate, which further suppresses rippling of the liquid surface. Also, in an embodiment in which the liquid column passes through both the first opening and the second opening, it is possible to further suppress the liquid column from directly falling onto the liquid surface.

[0065] 6) In some embodiments, the nanodroplet generating device according to any one of 1) to 5) above, The liquid tank is formed with an inlet (41) for the liquid and an outlet (49) for the liquid.

[0066] According to the configuration of 6) above, while the oscillator is vibrating, it is possible to continuously cause the inflow and outflow of liquid into the liquid tank, allowing the oscillator to vibrate within the flowing liquid. This prevents the oscillator's temperature from exceeding the upper limit temperature, allowing the oscillator to stably generate a mist containing nanodroplets. Therefore, the nanodroplet generator can stably supply nanodroplets to the main steam flow path.

[0067] 7) In some embodiments, the nanodroplet generating device described in 6) above is The vibrator unit includes an installation base (57) on which the vibrator is installed and which extends perpendicularly to the vertical direction; A leg portion (58) protruding downward from the installation base; Further includes:

[0068] According to the configuration of 7) above, the legs can be placed on the bottom wall of the liquid tank, so the vibrator can be placed at a predetermined depth in the liquid, allowing the vibrator to stably generate a mist containing nanodroplets.

[0069] 8) In some embodiments, the nanodroplet generating device according to 7) above, The inlet hole communicates with a liquid tank space (45) in the liquid tank below the installation base.

[0070] According to the configuration of 8) above, the liquid flowing in from the inlet flows around the installation base before reaching the liquid surface. The momentum of the liquid flow weakens during the detouring process. Therefore, compared to when the liquid passes through the inlet and reaches the liquid surface without detouring, rippling of the liquid surface can be suppressed.

[0071] 9) In some embodiments, the nanodroplet generating device according to 7) or 8) above, The legs are configured so that the amount of protrusion of the legs is adjustable.

[0072] According to the configuration of 9), the oscillator can be placed at a desired depth in the liquid, which allows the oscillator to stably generate a mist containing nanodroplets, and the nanodroplet generator can stably supply nanodroplets to the main steam flow path.

[0073] 10) In some embodiments, the nanodroplet generating device according to any one of 7) to 9) above, The liquid tank is a bottom wall portion (44) in which the inlet hole and the outlet hole are formed; a liquid tank partition (46) extending upward from the bottom wall between the inlet and outlet holes; further comprising The liquid tank partition is arranged to divide the liquid tank space (45) in the liquid tank into a settling space (451) in which the vibrator unit is submerged in the liquid, and a drainage space (452) in which the liquid overflowing the liquid tank partition flows out from the outflow hole.

[0074] According to the configuration of 10) above, the upper end of the liquid tank partition is approximately the same as the liquid level in the settling space. By setting the liquid tank partition to a predetermined vertical length, the liquid level can be adjusted to a desired height. This allows the vibrator to be placed at a desired depth in the liquid.

[0075] 11) In some embodiments, the nano-water droplet generating device according to 10) above, The liquid tank partition is configured so that the vertical length of the liquid tank partition is adjustable.

[0076] According to the above configuration 11), the liquid level can be adjusted, so that it becomes easier to set the depth of the vibrator to a desired value.

[0077] 12) In some embodiments, the nanodroplet generating device according to any one of 6) to 11) above, a supply pipe (71) for the liquid connected to the inlet; a drain pipe (79) for the liquid connected to the outlet hole; a flow regulation valve (88) disposed in at least one of the supply pipe or the drain pipe; a temperature sensor (89) for measuring the temperature of the liquid in the liquid tank; a controller (90) for feedback controlling the opening of the flow regulation valve so that the temperature measured by the temperature sensor falls within an allowable range; Further provided are:

[0078] The configuration of 12) above keeps the temperature in the liquid tank within an allowable range, preventing the oscillator temperature from exceeding the upper limit. As a result, the oscillator can stably generate a mist of nanodroplets, and the nanodroplet generator can stably supply nanodroplets to the main steam flow path.

[0079] 13) A steam turbine system (1) according to at least one embodiment of the present disclosure includes: A nano-water droplet generating device (5) according to any one of 1) to 12) above; the steam turbine (3) having the main steam flow path (4) into which the mixed fluid flows.

[0080] The configuration 13) above provides the same technical advantages as the configuration 1). [Explanation of symbols]

[0081] 1A, 1B(1): Steam turbine system 3: Steam turbine 3a: Entrance 4: Main steam flow path 5: Nano water droplet generator 6: Moving blade 7: Stator blade 8: Condenser 9:Liquid column 10: First partition plate 11: 1st opening hole 13: Compressor 15: Turbine section 19: First main body part 20: Second partition 22:Second opening hole 28: Second main body part 30: Chamber 31: Entrance 35: Mixed space 39: Outlet 40:Liquid tank 41:Inflow hole 44: Bottom wall 45:Liquid tank space 46: Liquid tank partition 49:Outflow hole 50: Transducer unit 55: Vibrator 57: Installation stand 58: Legs 59: Screw hole 71: Supply pipe 79: Drainage tube 87: Side wall 88: Flow adjustment valve 89: Temperature sensor 90: Controller 101: Supply tank 102: Drainage tank 103: Supply pump 105: Vacuum pump 451: Settling space 452: Drainage space 461: Fixed partition board 461a: screw hole 462: Movable partition 462a: Long hole 463: Fastening members C1,C2,Cv: Center Lq: Liquid Ls:Liquid level Ms: Fog

Claims

1. 1. A nano-water droplet generating apparatus for supplying a mixed fluid including nano-water droplets and a gas-phase fluid to a main steam path of a steam turbine, comprising: a chamber in which an inlet for introducing the gas-phase fluid, a mixing space for mixing the nanodroplets and the gas-phase fluid, and an outlet for discharging the mixed fluid are formed; a liquid tank configured to store a liquid below the mixing space; a vibrator unit including at least one vibrator configured to vibrate while submerged in the liquid in the liquid tank to generate a mist containing the nanodroplets in the mixing space; A nano-water droplet generating device comprising:

2. The mixing chamber further includes a first partition plate extending along a first horizontal direction to separate a liquid tank space in the liquid tank from the mixing space in the chamber, and having a first opening hole formed therein that is open in the vertical direction. The nano-water droplet generating device according to claim 1 .

3. the at least one oscillator is formed in a plate shape inclined with respect to the first horizontal direction, and is configured to generate a liquid column passing through the first opening by applying vibration to the liquid, The center of the first opening hole is offset from the center of the vibrator in a plan view. The nano-water droplet generating device according to claim 2 .

4. the inlet is disposed on one side in the first horizontal direction, and the outlet is disposed on the other side in the first horizontal direction; the plurality of vibrators as the at least one vibrator are arranged from the one side to the other side, The first partition plate has a plurality of first openings formed therein, each corresponding to one of the plurality of vibrators. The nano-water droplet generating device according to claim 3 .

5. Further provided is a second partition plate facing the first partition plate from above with a gap therebetween, The second partition plate has a second opening formed therein that is open in the vertical direction, The center of the second opening is offset from the center of the first opening in a plan view. The nano-water droplet generating device according to any one of claims 2 to 4.

6. The liquid tank has an inlet hole for the liquid and an outlet hole for the liquid. The nano-water droplet generating device according to any one of claims 1 to 3.

7. The vibrator unit includes a mounting base on which the vibrator is mounted and which extends perpendicularly to the up-down direction; a leg portion protruding downward from the installation base; Also includes The nano-water droplet generating device according to claim 6.

8. The inlet hole communicates with a liquid tank space in the liquid tank below the installation base. The nano-water droplet generating device according to claim 7 .

9. The leg portions are configured so that the amount of protrusion of the leg portions is adjustable. The nano-water droplet generating device according to claim 7 .

10. The liquid tank is a bottom wall portion in which the inlet hole and the outlet hole are formed; a liquid tank partition portion standing upright from the bottom wall portion between the inlet and outlet holes; Further including, The liquid tank partitioning portion is disposed so as to divide the liquid tank space in the liquid tank into a settling space in which the transducer unit is submerged in the liquid, and a drainage space in which the liquid overflowing the liquid tank partitioning portion flows out from the outflow hole. The nano-water droplet generating device according to claim 7 .

11. The liquid tank partition is configured so that the vertical length of the liquid tank partition is adjustable. The nano-water droplet generating device according to claim 10.

12. a supply pipe for the liquid connected to the inlet; a drain tube for the liquid connected to the outlet hole; a flow regulation valve disposed in at least one of the supply pipe and the drain pipe; a temperature sensor for measuring the temperature of the liquid in the liquid tank; a controller for feedback-controlling the opening degree of the flow regulation valve so that the temperature measured by the temperature sensor falls within an allowable range; The nano-water droplet generating device according to claim 6 , further comprising:

13. A nano-water droplet generating device according to any one of claims 1 to 3; the steam turbine having the main steam flow path into which the mixed fluid flows; A steam turbine system comprising:

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