Turbine through-flow auxiliary flow guide device

Abstract

The invention provides a steam turbine through-flow auxiliary flow guiding device, and relates to the field of steam turbines. The steam turbine through-flow auxiliary flow guiding device comprises a shell, a fixed ring is fixedly connected to the interior of the shell, a movable ring used for moving relative to the fixed ring is installed on the inner wall of the shell, a plurality of flow guiding channels used for stretching are fixedly connected between the movable ring and the fixed ring, and the flow guiding channels are of a gradually-shrinking and gradually-expanding structure; according to the steam turbine through-flow auxiliary flow guide device, by arranging the gradually-shrunk and gradually-expanded flow guide channels, steam is evenly distributed in the circumferential direction, the separation and vortex probability is reduced in cooperation with the flow guide plates, the steam can evenly act on blades of a steam turbine, the situation that local flow of the blades is too large or too small is avoided, and the flow of the blades is increased along with increase of steam kinetic energy. And the inclination angle of the flow guide plate and the aperture of the flow guide channel are also increased, so that the conveying capacity of steam is improved, the flow resistance of the steam is reduced, and the effective energy utilization rate of the steam is improved.

Description

Technical Field

[0001] The present invention relates to the field of steam turbines, and specifically to a through-flow auxiliary flow guiding device for a steam turbine. Background Art

[0002] A steam turbine is a rotary prime mover that converts the thermal energy of steam into mechanical energy. It includes a fixed part: a cylinder serves as the outer shell to form a steam space, nozzles convert the thermal energy of steam into kinetic energy, diaphragms fix the stationary blades and separate the spaces, and steam seals prevent steam leakage; a rotating part: a rotor composed of a main shaft, impellers, and moving blades is responsible for converting the kinetic energy of steam into mechanical energy, and there is also a coupling for connecting the rotors of other devices; auxiliary devices: bearings support the rotor, a regulating system controls the steam flow rate and speed, and a lubrication system provides lubrication and cooling; the steam turbine mainly converts the thermal energy of steam into kinetic energy and then into mechanical energy. When steam with a certain pressure and speed enters the moving blade passage, due to the shape and direction of the moving blade passage, the steam will change its flow direction. According to the momentum theorem, the momentum of the steam changes, generating an impact force on the moving blade, which pushes the moving blade to rotate and converts the kinetic energy of the steam into mechanical energy. In an impulse steam turbine, the steam completes the entire expansion and acceleration process in the nozzles and only changes the flow direction in the moving blades without further expansion and acceleration.

[0003] During the operation of traditional steam turbines, within the spatial region where steam flows, complex changes are likely to occur. For example, due to the structural characteristics of the through-flow part of the steam turbine, such as bends and variable cross-sections, the steam will generate turbulence and vortices when flowing through these regions, making it difficult for the steam to evenly impact the blades. As a result, local regions of the blades will bear excessive steam forces, and over time, the blades are prone to damage and require maintenance, which is rather troublesome. Therefore, there is an urgent need for a through-flow auxiliary flow guiding device that can optimize the steam flow and make the blades evenly stressed. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a through-flow auxiliary flow guiding device for a steam turbine, which solves the problem that it is difficult for steam to evenly impact the blades.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A through-flow auxiliary flow guiding device for a steam turbine includes a housing. A fixed ring is fixedly connected inside the housing. A movable ring for moving relative to the fixed ring is installed on the inner wall of the housing. A plurality of stretching flow guiding channels are fixedly connected between the movable ring and the fixed ring. The flow guiding channels are of a gradually shrinking and then expanding structure. A telescopic mechanism for controlling the movement of the movable ring is installed on the movable ring. A transmission mechanism is installed inside the fixed part of the telescopic mechanism. The fixed part is fixed relative to the fixed ring. A plurality of inclined flow guiding plates are provided on the outer side of the fixed part. When the flow guiding plates rotate, the free end of the telescopic mechanism is controlled to move through the transmission mechanism.

[0006] A number of groups of air holes are provided inside both the fixed ring and the movable ring. After the steam flows through the air holes inside the fixed ring, the diversion channel and the air holes inside the movable ring in sequence, it directly flows towards the deflector. The inclination angle of the deflector is adjusted by the driving force generated by the steam.

[0007] Preferably, one end of the outer shell is conical in shape, and a conical cover is fixedly connected inside the fixed ring. The outer shell and the conical cover are concentrically arranged.

[0008] Preferably, the diversion channel is made of a ceramic matrix composite material.

[0009] Preferably, the telescopic mechanism further includes a sliding member, a sleeve, a plug rod and a spring. The sliding member is rotationally and slidably connected to the fixed member. The plug rod is inserted into the sleeve. The two ends of the spring are respectively fixedly connected to the fixed member and the sleeve. The sleeve is rotationally connected to the sliding member. The movable ring is fixedly connected to the sleeve.

[0010] Preferably, the transmission mechanism includes a rotating member, a cam and a fixed shaft. A chute is provided inside the sliding member. The fixed shaft is slidably connected to the chute. One end of the rotating member is rotationally connected to the fixed member, and the other end is fixedly connected to the deflector. One end of the cam is fixedly connected to the rotating member, and the other end is rotationally connected to the fixed shaft.

[0011] Preferably, a connecting rod is fixedly connected between the fixed member and the conical cover. The movable ring is slidably connected to the connecting rod.

[0012] Preferably, a number of card slots are provided inside the sleeve. A convex block is clamped inside one of the card slots. An elastic sheet is fixedly connected between the convex block and the plug rod.

[0013] Preferably, the sizes of the number of card slots increase in sequence, and each card slot is arc-shaped.

[0014] Preferably, a number of the deflectors are arranged in a circular pattern, and the contact surface with the steam is a curved surface.

[0015] Preferably, each group of the diversion channels is a number of them, and each group of the diversion channels is arranged in a circular pattern.

[0016] Compared with the prior art, the present invention has the following beneficial effects: By setting one end of the outer shell to be conical and cooperating with a conical cover, the steam is guided to flow along the arc surface, so that it uniformly converges into the middle channel and then diffuses around, laying a foundation for subsequent stable diversion. By setting a diverging and converging diversion channel, the steam is evenly distributed in the circumferential direction. Cooperating with the diversion plate, the probability of separation and vortex is reduced, and the steam can uniformly act on the blades of the steam turbine, avoiding the situation of excessive or too small local flow rate on the blades. Moreover, as the kinetic energy of the steam increases, the inclination angle of the diversion plate increases, and the aperture of the diversion channel also increases accordingly, more effectively guiding the steam to impact the impeller, improving the efficiency of converting kinetic energy into mechanical energy, and improving the steam transportation capacity. The increase in the aperture of the diversion channel reduces the flow resistance of the steam in the diversion channel, reduces the pressure drop and energy loss caused by the resistance, and improves the effective energy utilization rate of the steam. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the outer shell of the present invention;

[0018] Figure 2 is a cross-sectional view of the front view of the outer shell of the present invention;

[0019] Figure 3 is a schematic structural diagram of the interior of the outer shell of the present invention;

[0020] Figure 4 is a cross-sectional view of the front view of the telescopic mechanism of the present invention;

[0021] Figure 5 For the present invention Figure 4 is an enlarged schematic diagram of the structure at A in;

[0022] Figure 6 is a cross-sectional view of the side view of the telescopic mechanism of the present invention;

[0023] Figure 7 is a cross-sectional view of the side view of the diversion channel of the present invention;

[0024] Figure 8 is a top view of the diversion plate of the present invention;

[0025] Figure 9 is a cross-sectional view of the top view of the diversion plate of the present invention;

[0026] Figure 10 is a schematic structural diagram of the fixing member of the present invention;

[0027] Figure 11 is a schematic structural diagram of the diversion plate and the transmission mechanism of the present invention.

[0028] Wherein: 1. Outer shell; 2. Fixed ring; 3. Movable ring; 4. Flow guiding channel; 5. Telescopic mechanism; 501. Fixed part; 502. Sliding part; 503. Sleeve; 504. Insert rod; 6. Transmission mechanism; 601. Rotating part; 602. Cam; 603. Fixed shaft; 7. Flow guiding plate; 8. Air hole; 9. Chute; 10. Connecting rod; 11. Card slot; 12. Convex block; 13. Elastic piece; 14. Conical cover. Detailed implementation mode

[0029] As Figures 1 - 11 shown, a steam turbine flow-through auxiliary flow guiding device includes an outer shell 1. A fixed ring 2 is fixedly connected inside the outer shell 1. One end of the outer shell 1 is conical. A conical cover 14 is fixedly connected inside the fixed ring 2. The outer shell 1 and the conical cover 14 are concentrically arranged. A movable ring 3 for moving relative to the fixed ring 2 is installed on the inner wall of the outer shell 1. A plurality of flow guiding channels 4 for stretching are fixedly connected between the movable ring 3 and the fixed ring 2. The flow guiding channels 4 are made of ceramic matrix composite materials, so that the flow guiding channels 4 not only have elasticity and toughness, but also are high temperature resistant. The flow guiding channels 4 are of a gradually shrinking and expanding structure. Each group of flow guiding channels 4 consists of several, and each group of flow guiding channels 4 is arranged in a circular pattern. A telescopic mechanism 5 for controlling the movement of the movable ring 3 is installed on the movable ring 3. The telescopic mechanism 5 further includes a sliding part 502, a sleeve 503, an insert rod 504 and a spring. The sliding part 502 is rotationally and slidably connected with the fixed part 501. The insert rod 504 is inserted into the sleeve 503. The two ends of the spring are respectively fixedly connected with the fixed part 501 and the sleeve 503. The sleeve 503 is rotationally connected with the sliding part 502. The movable ring 3 is fixedly connected with the sleeve 503. A connecting rod 10 is fixedly connected between the fixed part 501 and the conical cover 14. The movable ring 3 is slidably connected with the connecting rod 10. On the one hand, it ensures the relative fixation between the fixed part 501 and the conical cover 14, and on the other hand, it ensures the stable sliding of the movable ring 3. A plurality of card slots 11 are formed inside the sleeve 503. A convex block 12 is clamped in one of the card slots 11. An elastic piece 13 is fixedly connected between the convex block 12 and the insert rod 504. The sizes of the plurality of card slots 11 increase in sequence, and each card slot 11 is arc-shaped. A transmission mechanism 6 is installed inside the fixed part 501 of the telescopic mechanism 5. The transmission mechanism 6 includes a rotating part 601, a cam 602 and a fixed shaft 603. A chute 9 is formed inside the sliding part 502. The fixed shaft 603 is slidably connected with the chute 9. One end of the rotating part 601 is rotationally connected with the fixed part 501, and the other end is fixedly connected with the flow guiding plate 7. One end of the cam 602 is fixedly connected with the rotating part 601, and the other end is rotationally connected with the fixed shaft 603. The fixed part 501 is fixed relative to the fixed ring 2. A plurality of inclined flow guiding plates 7 are arranged on the outer side of the fixed part 501. When the flow guiding plate 7 rotates, the free end of the telescopic mechanism 5 is controlled to move through the transmission mechanism 6.

[0030] A number of groups of air holes 8 are provided inside both the fixed ring 2 and the movable ring 3. After the steam flows through the air holes 8 inside the fixed ring 2, the diversion channel 4 and the air holes 8 inside the movable ring 3 in sequence, it directly flows towards the deflector 7. The inclination angle of the deflector 7 is adjusted by the driving force generated by the steam. A number of deflectors 7 are arranged in a circular pattern, and the contact surface with the steam is a curved surface.

[0031] During use, the outer shell 1 is fixed inside the moving blade passage and is located in front of the rotating part of the steam turbine. Moreover, the outer shell 1, the main shaft of the rotating part of the steam turbine, and the impeller are on the same axis, enabling the steam to enter the outer shell 1. Since one end of the outer shell 1 is conical and is matched with the conical cover 14, when the steam flows from the intake end of the outer shell 1 to the other end, the steam converges into the channel in the middle along the arc surface of the outer shell 1 and then uniformly diffuses around along the arc surface of the conical cover 14. At this time, the steam is at the fixed ring 2. After the steam flows through the air holes 8 inside the fixed ring 2, the diversion channel 4 and the air holes 8 inside the movable ring 3 in sequence, it directly flows towards the deflector 7. Through the provision of a number of groups of diversion channels 4 arranged in a circular pattern, each diversion channel 4 has a gradually shrinking and then expanding structure, and a number of diversion channels 4 should be equally spaced. The circular arrangement can make the steam evenly distributed in the circumferential direction. Each diversion channel 4 can guide the steam, enabling the steam to flow in a predetermined direction, improving the accuracy and efficiency of diversion, and helping the steam to be evenly distributed. The diversion channel 4 is set to have a gradually shrinking and then expanding structure. In the gradually shrinking section, the steam velocity gradually increases, which can effectively avoid the occurrence of low-velocity areas and eddies in the steam, reducing energy loss. In the gradually expanding section, the steam velocity gradually decreases again, enabling the steam to flow out of the diversion channel 4 smoothly, improving the stability of the entire flow field. Moreover, when the steam flows through the diversion channel 4, it can improve the conversion effect of pressure energy and kinetic energy. In the gradually shrinking section, the pressure energy is gradually converted into kinetic energy. In the gradually expanding section, part of the kinetic energy can be converted back into pressure energy. This energy conversion process helps to improve the energy utilization efficiency of the steam turbine, enhancing the work capacity of the steam. And the gradually shrinking and then expanding structure of the diversion channel 4 can make the steam flow more smoothly inside the channel, reducing the energy loss caused by flow separation and eddy phenomena, thereby further improving the energy conversion efficiency of the steam turbine.

[0032] Subsequently, the steam moves along several guide vanes 7 and finally contacts the impeller of the steam turbine. The impact force of the steam will drive the impeller to rotate, thereby converting the kinetic energy of the steam into mechanical energy. Since several guide vanes 7 are arranged in a circular pattern, the incoming steam can be evenly distributed in all directions, enabling the steam to be more uniformly distributed within the circular range. As a result, the steam can flow evenly towards the impeller of the steam turbine, causing the blades of the impeller to be evenly stressed and avoiding situations where the local flow rate of the blades is too large or too small. Due to the curved surface and inclined initial angle of the guide vane 7, the flow direction of the steam can be guided, causing the steam to flow along a predetermined path, reducing the flow resistance and air flow disorder. Moreover, the steam can be smoothly guided, enabling the steam to better conform to the surface of the guide vane 7 during the flow process, thereby reducing the probability of steam separation and vortex formation.

[0033] Subsequently, as Figure 4 and Figure 5 shown, due to the curved surface and inclined setting of the guide vane 7, when the kinetic energy of the steam increases, the force exerted by the steam on the guide vane 7 also increases accordingly. The guide vane 7 begins to rotate, driving the rotating member 601 to rotate. The rotating member 601 drives the cam 602 to rotate, the cam 602 drives the fixed shaft 603 to rotate, the fixed shaft 603 drives the sliding member 502 to move, the sliding member 502 drives the sleeve 503 to move, and the sleeve 503 drives the movable ring 3 to move. The movable ring 3 pulls one end of the diversion channel 4 to move away from the fixed ring 2, causing the diversion channel 4 to deform. For the deformed diversion channel 4, the diameter of its smaller internal aperture begins to increase, increasing the flow area of the channel and enabling the diversion channel 4 to allow a larger amount of steam to pass through, improving the steam transportation capacity. Moreover, the increase in the aperture of the diversion channel 4 reduces the flow resistance of the steam within the diversion channel 4, reducing the pressure drop and energy loss caused by the resistance and improving the effective energy utilization rate of the steam. When the guide vane 7 rotates, its inclination angle also increases. As the inclination angle of the guide vane 7 increases, the steam will obtain acting forces in different directions and magnitudes when flowing through the guide vane 7, enabling the flow direction of the steam to be better guided and making more full use of the kinetic energy of the steam. A reasonable increase in the angle of the guide vane 7 can enable the steam to more effectively impact the impeller, converting the kinetic energy of the steam into the mechanical energy of the impeller more efficiently and improving the power generation efficiency of the steam turbine.

[0034] Finally, through a plurality of arranged card slots 11, bumps 12 and elastic sheets 13, and the sizes of the plurality of card slots 11 increase in sequence. In the initial position, the bump 12 should be located in the card slot 11 with the smallest size. As the steam pressure increases, when the plug 504 moves, it overcomes the resistance between the bump 12 and this card slot 11, and makes the bump 12 move into the next card slot 11, and progresses in sequence; since the contact areas between the multiple card slots 11 and the bump 12 increase in sequence, when the bump 12 progresses to the next card slot 11, the contact area between the two increases, enabling it to have a higher upper limit of friction. This enables the bump 12 and the card slot 11 to better maintain a relatively stable state when the steam pressure fluctuates continuously, effectively avoiding excessive rotation or displacement of the deflector 7 caused by instantaneous pressure fluctuations. At the same time, the increase in the contact area also enhances the positioning of the rotation angle of the deflector 7, ensuring that the deflector 7 can accurately guide the steam flow at different steam pressures; when the plug 504 moves, it compresses the spring. When the steam flow rate decreases, the elastic force of the spring can push the plug 504 to reset, thereby enabling the deflector 7 to return to its original position.

[0035] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A steam turbine flow auxiliary guide device, characterized in that: The invention comprises a shell (1), wherein a fixed ring (2) is fixedly connected to the inside of the shell (1), a movable ring (3) for moving relative to the fixed ring (2) is installed on the inner wall of the shell (1), a plurality of guide channels (4) for stretching are fixedly connected between the movable ring (3) and the fixed ring (2), the guide channels (4) are of a gradually contracting and expanding structure, a telescopic mechanism (5) for controlling the movement of the movable ring (3) is installed on the movable ring (3), a transmission mechanism (6) is installed in a fixing member (501) of the telescopic mechanism (5), the fixing member (501) is fixed relative to the fixed ring (2), a plurality of inclined guide plates (7) are arranged on the outer side of the fixing member (501), and when the guide plates (7) rotate, the free end of the telescopic mechanism (5) is controlled to move through the transmission mechanism (6); A plurality of groups of air holes (8) are provided inside the fixed ring (2) and the movable ring (3). Steam flows through the air holes (8) in the fixed ring (2), the guide channel (4) and the air holes (8) in the movable ring (3) in sequence, and then flows directly to the guide plate (7). The inclination angle of the guide plate (7) is adjusted by the driving force generated by the steam.

2. The auxiliary flow guiding device for steam turbine according to claim 1, characterized in that: One end of the outer shell (1) is in a cone shape, a cone cover (14) is fixedly connected to the interior of the fixing ring (2), and the outer shell (1) and the cone cover (14) are concentrically arranged.

3. The auxiliary flow guiding device for steam turbine according to claim 1, characterized in that: The flow guide channel (4) is made of a ceramic-based composite material.

4. The auxiliary flow guiding device for steam turbine according to claim 1, characterized in that: The telescopic mechanism (5) further comprises a sliding member (502), a sleeve (503), an insertion rod (504) and a spring. The sliding member (502) is rotatably and slidably connected to the fixing member (501), the insertion rod (504) is plugged into the sleeve (503), two ends of the spring are respectively fixedly connected to the fixing member (501) and the sleeve (503), the sleeve (503) is rotatably connected to the sliding member (502), and the movable ring (3) is fixedly connected to the sleeve (503).

5. The auxiliary flow guiding device for steam turbine according to claim 4, characterized in that: The transmission mechanism (6) comprises a rotating member (601), a cam (602) and a fixed shaft (603); a sliding groove (9) is provided inside the sliding member (502); the fixed shaft (603) is slidably connected to the sliding groove (9); one end of the rotating member (601) is rotatably connected to the fixed member (501), and the other end is fixedly connected to the guide plate (7); one end of the cam (602) is fixedly connected to the rotating member (601), and the other end is rotatably connected to the fixed shaft (603).

6. The auxiliary flow guiding device for steam turbine according to claim 2, characterized in that: A connecting rod (10) is fixedly connected between the fixing member (501) and the conical cover (14), and the movable ring (3) is slidably connected to the connecting rod (10).

7. The auxiliary flow guiding device for steam turbine according to claim 4, characterized in that: The sleeve (503) is provided with a plurality of slots (11) inside, wherein a protrusion (12) is clamped inside one of the slots (11), and an elastic sheet (13) is fixedly connected between the protrusion (12) and the insertion rod (504).

8. The auxiliary flow guiding device for steam turbine according to claim 7, characterized in that: The sizes of the plurality of slots (11) increase in sequence, and each slot (11) is in an arc shape.

9. The steam turbine flow auxiliary guide device according to claim 1, characterized in that: The guide plates (7) are arranged in a circle, and the contact surface with the steam is a curved surface.

10. The steam turbine flow auxiliary guide device according to claim 1, characterized in that: Each group of the guide channels (4) comprises a plurality of guide channels (4), and each group of the guide channels (4) are arranged in a circular pattern.

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