Water capture device of steam turbine and steam turbine

Abstract

The present application provides a steam turbine water-collecting device and a steam turbine, wherein the water-collecting device comprises an annular water-collecting cover plate, the water-collecting cover plate is used to be arranged between the partition plates of two adjacent stages of stationary blade assemblies, the water-collecting cover plate is provided with a plurality of through grooves distributed along the circumferential direction and penetrating along the inside and outside; a plurality of grooves are also provided on the inner side of the water-collecting cover plate between two adjacent through grooves, the grooves are connected to the through grooves, and the grooves are arranged obliquely relative to the circumferential direction of the water-collecting cover plate. The water-collecting device can improve the efficiency of hydrophobic dehumidification.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbines, and in particular to a water capture device of a steam turbine and a steam turbine. Background Art

[0002] The last two blades of the low-pressure flow of the steam turbine usually work in the wet steam area. The steam contains water. Long-term operation will cause corrosion and wear on the blade surface, which will have an adverse effect on the safety and economy of the blade. In order to avoid the above hazards, a variety of active and passive protection measures can be taken. The moisture that needs to be drained in the low-pressure flow of the steam turbine is mainly the water film attached to the metal wall outside the flow and the water droplets mixed in the steam. The water droplets move to the periphery of the flow under the inertial force of the impeller rotation. At present, the dehumidification ring is mainly used for dehumidification and drainage, but the efficiency is low. Summary of the invention

[0003] The purpose of the present application is to provide a water capture device for a steam turbine and a steam turbine, which can improve the efficiency of water drainage and dehumidification.

[0004] The present application provides a water-catching device for a steam turbine, the water-catching device comprising an annular water-catching cover plate, the water-catching cover plate being used to be arranged between partitions of two adjacent stages of stationary blade assemblies, the water-catching cover plate being provided with a plurality of through grooves distributed along the circumferential direction and penetrating inside and outside; a plurality of grooves are further provided on the inner side of the water-catching cover plate between two adjacent through grooves, the grooves being connected to the through grooves, and the grooves being arranged obliquely relative to the circumferential direction of the water-catching cover plate.

[0005] Optionally, the inner side of the water-catching cover plate is provided with a first annular groove on one axial side and a second annular groove on the other axial side; one end of the through groove is connected to the first annular groove, and the other end of the through groove is connected to the second annular groove;

[0006] Along the axial direction, the groove located in the middle area between two adjacent through grooves is connected to one through groove at one end and connected to another adjacent through groove at the other end; the groove located in the end area on the steam inlet side or the end area on the steam outlet side between two adjacent through grooves is connected to one through groove at one end and connected to the corresponding first annular groove or the second annular groove at the other end.

[0007] Optionally, the through groove extends from one axial side of the water-catching cover plate to the other axial side, and the extending direction of the through groove is perpendicular to the circumferential direction of the water-catching cover plate.

[0008] Optionally, the water-catching cover plate is used to enclose a wall to form the through groove, including a first side wall and a second side wall arranged opposite to each other in the circumferential direction, and the first side wall is perpendicular to the inner surface of the water-catching cover plate;

[0009] The second side wall has an acute angle with the inner surface of the water-catching cover plate; or, the second side wall includes a second side wall inner section and a second side wall outer section distributed from the inside to the outside, the second side wall outer section has a first angle with the inner surface of the water-catching cover plate, the second side wall inner section has a second angle with the inner surface of the water-catching cover plate, the first angle is an acute angle, and the second angle is greater than the first angle and not greater than 90°.

[0010] Optionally, the water-catching cover plate is an arched structure that is concave from the outside to the inside.

[0011] Optionally, the radial dimension of the water-catching cover plate gradually increases in the axial direction, and the width of the through groove increases as the radial dimension increases.

[0012] Optionally, flanges are provided on both sides of the water-catching cover plate along the axial direction, and the flanges are used to be connected and fixed to the corresponding partition plates.

[0013] Optionally, the water-catching covering plate comprises a first covering plate section and a second covering plate section, and the first covering plate section and the second covering plate section are butted together along the circumferential direction to form the water-catching covering plate;

[0014] The flange corresponds to the part of the first covering plate section and the corresponding partition, one of which is provided with a dovetail protrusion, and the other is provided with a dovetail groove matching with the dovetail protrusion; the flange corresponds to the part of the second covering plate section and the corresponding partition, one of which is provided with a convex stopper, and the other is provided with a concave stopper matching with the dovetail protrusion.

[0015] Optionally, it also includes an annular hydrophobic covering plate, which is used to be arranged on the inner side of the partition of the upstream stationary blade assembly in two adjacent stages of stationary blade assemblies and faces the shroud of the moving blade assembly; the inner side of the hydrophobic covering plate is provided with a plurality of circumferentially distributed hydrophobic grooves, and the hydrophobic grooves are inclined relative to the hydrophobic covering plate.

[0016] Optionally, in the axial direction, a side of the hydrophobic cover plate close to the water-catching cover plate has an annular slope surface, and the hydrophobic grooves are all connected to the slope surface.

[0017] Optionally, the slope surface is flush with the inner surface of the water-catching cover plate.

[0018] The present application also provides a steam turbine, comprising a moving blade assembly and a stationary blade assembly, and also comprising a water capture device for the steam turbine as described in any of the above items, wherein the water capture cover plate of the water capture device has an acute angle with the steam inlet direction and the rotation direction of the moving blade assembly.

[0019] Optionally, the water-catching cover plate is provided with a first flange on one side along the axial direction and a second flange on the other side along the axial direction, and the first flange and the second flange are respectively used to be connected and fixed to the corresponding partition; the outer annular surfaces of the first flange and the second flange are inclined surfaces, which cooperate with the corresponding partition to form an annular drainage groove.

[0020] After the water-catching cover plate of the present application is set to the steam turbine, the grooves set on the inner side of the water-catching cover plate can collect the accumulated water relatively efficiently, and the surface tension of the liquid film attached to the water-catching cover plate makes the liquid phase water flow into the back of the water-catching cover plate through the through grooves on the water-catching cover plate. The back of the water-catching cover plate is a space that will not be torn and atomized by the mainstream steam, thereby improving the effect of water capture and drainage, and achieving a better dehumidification purpose. Especially in the case of heat recovery steam extraction, the heat recovery steam extraction can further improve the ability of liquid phase water to pass through the water-catching cover plate, and the drainage efficiency can reach 46% when there is heat recovery steam extraction. Compared with the general drainage efficiency of steam turbines, which is only a few percent at most, the improvement is relatively large. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the position of the water capture device in the steam turbine in the embodiment of the present application, which only illustrates half of the radial direction;

[0022] Figure 2 for Figure 1 A magnified view of the middle A area;

[0023] Figure 3 for Figure 2 Enlarged view of the B area;

[0024] Figure 4 for Figure 3 The view of the water-catching cover plate in the middle along the P direction;

[0025] Figure 5 for Figure 4 Enlarged view of the B area;

[0026] Figure 6 for Figure 4 Middle AA section view;

[0027] Figure 7 for Figure 4 Middle BB view;

[0028] Figure 8 for Figure 7 Enlarged view of the middle I part;

[0029] Fig. 9 for Figure 4 Middle CC section view;

[0030] Fig.10It is a schematic diagram of the connection between the second part of the first flange and the second part of the second flange and the partition;

[0031] Fig.11 for Figure 3 The view of the hydrophobic cover along the Q direction, that is, Figure 3 Bottom view of the hydrophobic cover plate.

[0032] The description of the reference numerals in the above drawings is as follows:

[0033] 100-first stationary blade assembly; 101-first partition plate; 102-first stationary blade;

[0034] 200 - second stationary blade assembly; 201 - second partition plate; 202 - second stationary blade;

[0035] 301-water-catching cover plate; 301a-groove; 301b-through groove; 301c-first annular groove; 301d-second annular groove; 301e-second side wall; 301e1-inner section of second side wall; 301e2-outer section of second side wall; 301f-first side wall;

[0036] 302-hydrophobic cover plate; 302a-hydrophobic groove; 302b-third annular groove; 302c-slope surface;

[0037] 303-first flange; 3031-first dovetail protrusion; 3032-first convex stop; 304-second flange; 3041-second dovetail protrusion; 3042-inner annular surface; 3043-second convex stop; 305-screw;

[0038] 400-steam extraction chamber;

[0039] 500-moving blade assembly; 501-shroud; 502-moving blade;

[0040] a-first drainage groove; b-second drainage groove. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0042] Please refer to Figure 1-3 , Figure 1 This is a schematic diagram of the position of the water capture device in the steam turbine in the embodiment of the present application, which only illustrates half of the radial direction; Figure 2 for Figure 1 A magnified view of the middle A area; Figure 3 for Figure 2 Magnified view of area B.

[0043] The steam turbine in this embodiment is provided with a water-catching device, which includes an annular water-catching cover plate 301. The water-catching cover plate 301 is used to be arranged between the partition plates of two adjacent stages of stationary blade assemblies. Figure 1 As shown, three stationary blade assemblies are schematically shown. Along the steam inlet direction, the two stationary blade assemblies located downstream are the first stationary blade assembly 100 and the second stationary blade assembly 200. Specifically, the first stationary blade assembly 100 is the last-stage stationary blade assembly, and the second stationary blade assembly 200 is the second-last-stage stationary blade assembly. The last-stage stationary blade assembly and the second-last-stage stationary blade assembly are the last two-stage stationary blade assemblies of the low-pressure flow of the steam turbine. The two-stage stationary blade assemblies work in the wet steam area and have a greater dehumidification demand. It can be seen that the water-catching cover plate 301 can also be set between the partitions of other adjacent stationary blade assemblies with dehumidification demands. Figure 1 Also illustrated is a moving blade assembly 500 located between two stationary blade assemblies.

[0044] The stationary blade assembly includes a plurality of stationary blades and an annular partition located outside the stationary blades, and the plurality of stationary blades are connected to the partition. Figure 1 The first stationary blade 102, the second stationary blade 202, the first partition 101, and the second partition 201 are schematically shown. The moving blade assembly 500 includes moving blades 502 and a shroud 501 located outside the plurality of moving blades 502. The plurality of moving blades 502 are connected to the shroud 501. In the axial direction, there is an annular gap between the adjacent first partitions 101 and second partitions 201. The water-catching cover plate 301 of the water-catching device is arranged at the position of the annular gap. The two sides of the water-catching cover plate 301 in the axial direction can be connected to the corresponding partition plates respectively, so as to connect the two partition plates. The two sides of the water-catching cover plate 301 in the axial direction are the steam inlet side and the steam outlet side thereof.

[0045] Please continue to refer to Figure 4-6 understand, Figure 4 for Figure 3 The view of the water-catching cover plate 301 along the P direction, that is, Figure 3 A bottom view of the middle water-catching cover plate 301; Figure 5 for Figure 4 Enlarged view of the B area; Figure 6 for Figure 4 AA section view.

[0046] As mentioned above, the water-catching cover plate 301 is an annular structure, which is coaxially arranged with the stationary blade assembly. Figure 4The diagram shows a radial projection of a section of the water-catching cover plate 301 along the circumferential direction. The circumferential direction mentioned in the present application refers to the circumferential direction. The water-catching cover plate 301 in the present embodiment is provided with a plurality of through grooves 301b distributed along the circumferential direction and penetrating inside and outside. The "inside" and "outside" mentioned in the present application are relative to the central axis. The direction close to the central axis is the inside, and the opposite direction is the outside. The "inside" and "outside" of the water-catching cover plate 301 are relative to the central axis of the water-catching cover plate 301. However, in fact, the central axis of the water-catching cover plate 301 overlaps with the central axis of the steam turbine. It can be seen that the through grooves 301b of the water-catching cover plate 301 actually penetrate along the thickness direction of the water-catching cover plate 301. In this way, after the water-catching cover plate 301 is installed between the first baffle plate 101 and the second baffle plate 201, the through grooves 301b can connect the internal flow of the steam turbine with the external steam extraction chamber 400 (shown in FIG. 1 ). Figure 1 ), the extraction chamber 400 is specifically the extraction chamber of the low-pressure cylinder of the steam turbine, and the flow passage is a channel for flowing steam in the steam turbine, and the channel includes an internal flow passage formed by a stationary blade assembly and a moving blade assembly 500.

[0047] In addition, a plurality of grooves 301a are provided on the inner side of the water-catching cover plate 301. Along the circumference of the water-catching cover plate 301, a plurality of grooves 301a are provided between two adjacent through grooves 301b. The plurality of grooves 301a between two adjacent through grooves 301b are distributed along the axial direction. The grooves 301a are connected with the through grooves 301b. The grooves 301a are inclined relative to the circumference, that is, the grooves 301a and the circumference of the water-catching cover plate 301 have an angle, and the angle is not a right angle. In this way, the rotation of the moving blades 502 can be used to drive the water film on the periphery of the flow and the water droplets thrown into the periphery of the flow into the grooves 301a for collection. It should be known that the moving blade 502 rotates in the circumferential direction, so the rotation direction of the moving blade 502 is parallel to the circumferential direction of the water-catching cover plate 301. When the water-catching cover plate 301 is installed on the steam turbine, the groove 301a has an angle with the circumferential direction of the water-catching cover plate 301, and then has an angle α with the rotation direction of the moving blade 502. Since the rotation direction of the moving blade 502 is a vector, the angle α between the groove 301a and the rotation direction of the moving blade 502 should be an acute angle. In this way, the groove 301a is inclined along the rotation direction of the moving blade 502, so that the water film, water droplets, etc. near the periphery of the flow are driven by the steam flow of the moving blade 502 to flow along the groove 301a, and enter the through groove 301b from the groove 301a, and then flow out of the flow, such as Figure 4 As shown, if the rotating blades rotate in the opposite direction, the water film, water droplets, etc. cannot enter the groove 301a under the driving of the rotating airflow. Of course, Figure 4In the embodiment, if the steam inlet direction and the rotation direction of the moving blade 502 are changed in the opposite direction at the same time, the groove 301a can still collect the accumulated water. Therefore, in fact, when the water-catching cover plate 301 is installed in the steam turbine, it is required that the groove 301a has an acute angle with the steam inlet direction and the rotation direction of the moving blade 502. The angle α between the groove 301a and the rotation direction is selected to be about 30°, for example, which is conducive to introducing the water film, water droplets, etc. near the water-catching cover plate 301 into the groove 301a under the action of the rotating airflow, and is also conducive to realizing the introduction of the accumulated water in the groove 301a into the through groove 301b.

[0048] In this embodiment, the width m of the groove 301a can be selected as 1mm-3mm, and the spacing n between two adjacent grooves 301a can be selected as 1mm-3mm, for example. The specific selection of the size can be determined according to the water content in the steam. The larger the water content, the larger the width of the groove 301a can be set, and the spacing n between each groove 301a can be set to be smaller. Conversely, the smaller the water content in the steam, the smaller the width of the groove 301a can be set, and the spacing n between each groove 301a can be set to be larger. Figure 6 As shown, the groove 301a has a depth h, which is the dimension of the groove 301a in the thickness direction of the water-catching cover plate 301. The depth h can be set to 1mm-3mm. If the groove 301a is too shallow, water will not easily enter the groove 301a. If the groove 301a is too deep, it will be difficult to flow. Of course, the depth of the groove 301a can be adjusted according to actual working conditions.

[0049] In addition, the groove 301a can be designed as a semicircular structure, that is, the cross section of the groove 301a can be a semicircular, such as Figure 6 As shown, the radius r of the groove 301a is equal to the depth h. Of course, if the groove 301a is a small semicircular structure or a large semicircular structure, the radius r and the depth h may be different. The groove 301a of this structural form has the advantages of simple design and easy processing and manufacturing, and can avoid stress concentration on the water-catching cover plate 301.

[0050] It is worth noting that in this embodiment, the inner side of the water-catching cover plate 301 is further provided with a first annular groove 301c on one axial side and a second annular groove 301d on the other axial side. Figure 4 , the two annular grooves are located on both sides of the axial direction of the water-catching cover plate 301, that is, Figure 4 One end of the through groove 301b is connected to the first annular groove 301c, and the other end of the through groove 301b is connected to the second annular groove 301d, so that the water vapor, water droplets and other accumulated water in the first annular groove 301c and the second annular groove 301d can flow to the through groove 301b.

[0051] Combination Figure 4 , 5 It is understood that, since a plurality of grooves 301a distributed along the axial direction are arranged between two adjacent through grooves 301b, and the grooves 301a are arranged at an angle, in order to arrange more grooves 301a, some grooves 301a located in the end regions on both sides of the axial direction of the water-catching cover plate 301 may not be able to communicate with two adjacent through grooves 301b at the same time. That is, the groove 301a located in the middle region between two adjacent through grooves 301b is connected to a through groove 301b at one end, and is connected to another adjacent through groove 301b at the other end; the groove 301a located in the end region between two adjacent through grooves 301b is connected to a through groove 301b at one end, and is connected to the corresponding first annular groove 301c or second annular groove 301d at the other end. Figure 5 Only one end of the groove 301a in the middle right end region is connected to a through groove 301b, and the other end is located at the right end edge of the water-catching cover plate 301, that is, at the steam outlet side edge. According to the rotation direction of the moving blade 502, the flow direction of the fluid in the groove 301a is from one end to the other end. Figure 5 From a visual perspective, that is, it flows from the left end to the right end, if no annular groove is set, some grooves 301a in the end area that are not connected to the through groove 301b will not be able to discharge the accumulated water vapor, water droplets and other accumulated water into the through groove 301b. After the annular groove is set, it can be ensured that the accumulated water in each groove 301a can be discharged.

[0052] The specific dimensions of the groove 301a mentioned above and the dimensions of the through groove 301b can also be optimized. Figure 7-9 As shown, Figure 7 for Figure 4 Middle BB view; Figure 8 for Figure 7 Enlarged view of the middle I part; Fig. 9 for Figure 4 CC section view.

[0053] The width s of the through slot 301b is the size along the circumferential direction, and the width s can be set to 5mm-10mm. Figure 4 As shown, the length L of the through groove 301b is the dimension in the axial direction. The length L of the through groove 301b can be the same as or slightly larger than the dimension of the coverage area of ​​the groove 301a in the axial direction, so as to ensure that all the accumulated water in the groove 301a can enter the steam extraction chamber 400 through the through groove 301b. Figure 5 As shown, it may be a circular structure 301 b 1 to reduce stress concentration on the water-catching cover plate 3011 .

[0054] The pitch t between each through groove 301b can be set to 50mm-100mm, and the pitch t is the distance between two adjacent through grooves 301b. As mentioned above, the water film attached to the periphery of the through flow, the water droplets mixed in the steam, etc. can flow out from the through groove 301b of the water-catching cover plate 301 under the rotation of the moving blades 502 to achieve the purpose of water capture and dehumidification. For the steam turbine that performs heat recovery steam extraction, the power of dehumidification also comes from heat recovery steam extraction, that is, steam is extracted from the through flow for use. At this time, the suction force can further strengthen the suction of the water film, water droplets, etc. attached to the metal wall surface of the through flow periphery, so that it can pass through the water-catching cover plate 301 more smoothly. The pitch t of the through groove 301b can be set according to the amount of heat recovery steam extraction. The setting of this pitch t and width s is preferably satisfied: when the maximum amount of heat recovery steam extraction flows through, the flow rate of steam passing through the through groove 301b does not exceed the predetermined speed, and the predetermined speed is, for example, 50 meters per second. The pitch t and width s will affect the speed of the extracted steam. If the width s is too large, the flow rate will be too low. If the width s is too small, the flow rate will be too fast. The pitch t is related to the number of through slots 301b, which is also related to the amount of extracted steam and the dehumidification capacity. Therefore, the predetermined speed can be set according to the speed requirements of the heat recovery extraction, and the pitch t between adjacent through slots 301b and the width s of the through slots 301b can be set accordingly.

[0055] like Figure 2 , 3 As shown, the radial dimension of the water-catching cover plate 301 gradually increases from the steam inlet side to the steam outlet side in the axial direction. Generally, the radial dimensions of the baffles of the stationary blade assemblies of two adjacent stages are different. The water-catching cover plate 301 is arranged in this way to better connect the first baffle plate 101 and the second baffle plate 201, so that the steam in the flow is smoother. That is, the water-catching cover plate 301 is a truncated cone structure, the diameter of the steam inlet side of the water-catching cover plate 301 is R1, and the diameter of the steam outlet side is R2, R2 is greater than R1, at this time, it can be considered to set the width s of the through groove 301b on the side of the diameter R2 to be larger, that is, the width s of the through groove 301b at each position in the axial direction is not completely equal, and can be increased or decreased accordingly according to the increase or decrease of the radial dimension to meet the requirements of flow rate and dehumidification.

[0056] like Figure 4 As shown, the through groove 301b in this embodiment extends from one axial side of the water-catching cover plate 301 to the other side, and the extending direction of the through groove 301b is perpendicular to the circumferential direction of the water-catching cover plate 301, so that the accumulated water in the multiple grooves 301a can be better collected. Of course, the through groove 301b and the circumferential direction may have a certain angle.

[0057] like Figure 8As shown, the water-catching cover plate 301 in this embodiment is used to enclose the wall of the through groove 301b, including a first side wall 301f and a second side wall 301e arranged opposite to each other in the circumferential direction, wherein the first side wall 301f is perpendicular to the inner side of the water-catching cover plate 301. In addition, the second side wall 301e in this embodiment includes a second side wall inner section 301e1 and a second side wall outer section 301e2 distributed from the inside to the outside, the second side wall outer section 301e2 and the inner surface of the water-catching cover plate 301 have a first angle g, the second side wall inner section 301e1 and the water-catching cover plate 301 have a second angle, the first angle g is an acute angle, and the second angle is greater than the first angle g and not greater than 90°, so that the second side wall inner section 301e1 can form a blunt edge at the inner edge of the through groove 301b, that is, the second side wall 301e is processed into a chamfer with a blunt edge. In addition, the second side wall 301e is the side facing the rotation direction, so that when steam, water film or water droplets flow out from the through groove 301b, they will impact the second side wall 301e, and the blunt edge can reduce the wear caused by the impact and extend the service life of the water-catching cover plate 301. The second side wall outer section 301e2 is set to have a first angle g with the inner side, which has a diversion effect. Of course, it is also possible for the second side wall 301e as a whole to have an acute angle with the inner surface of the water-catching cover plate 301.

[0058] like Figure 8 As shown, the height w of the second side wall inner section 301e1 as a blunt edge in the inner and outer directions can be set to 1mm, and the first angle g between the second side wall outer section 301e2 as a chamfer and the inner side of the water-catching cover plate 301 can be 30°-45°. Except for the chamfered position, the sharp angles of the edges of other positions of the through groove 301b can be retained, but burrs should be eliminated to ensure smooth flow of steam, water droplets, etc.

[0059] The thickness of the water-catching cover plate 301 can be selected according to the strength and stiffness calculation results of the steam turbine, for example, set to 5mm-10mm, which is consistent with the depth of the through groove 301b. The larger the radial dimension of the water-catching cover plate 301 is, the larger the thickness is adaptively set. The outer surface of the water-catching cover plate 301 can be a smooth surface, so that even if the discharged accumulated water falls back to the outside of the water-catching cover plate 301, it is easy to slide into the steam extraction chamber 400 below as soon as possible.

[0060] like Figure 2As shown, the water-catching cover plate 301 in this embodiment is an arched structure that is concave from the outside to the inside. When the steam turbine is working, the steam temperature will change, which will cause the axial distance between the first baffle 101 and the second baffle 201 to change. The two axial sides of the water-catching cover plate 301 of this embodiment are respectively connected to the first baffle 101 and the second baffle 201, and the water-catching cover plate 301 is set to an arched structure and is concave from the outside to the inside. When the axial distance between the first baffle 101 and the second baffle 201 becomes smaller, the axial size of the water-catching cover plate 301 will be squeezed to increase its arch; when the distance between the first baffle 101 and the second baffle 201 becomes larger, the water-catching cover plate 301 will be stretched to reduce its arch. In this way, the elastic deformation of the arched structure of the water-catching cover plate 301 eliminates the influence of the change in the axial distance between the first baffle 101 and the second baffle 201, so as to compensate for the difference between the change in the axial distance and the change in the axial expansion of the water-catching cover plate 301. The water-catching cover plate 301 may be specifically made of stainless steel, and the arched arrangement enables it to have axial deformation capability.

[0061] like Figure 2 As shown, in this embodiment, the water-catching cover plate 301 is provided with a first flange 303 on one side along the axial direction, and a second flange 304 on the other side along the axial direction. The first flange 303 and the second flange 304 are respectively used to connect and fix with the corresponding partitions, that is, the first flange 303 is connected and fixed with the first partition 101, and the second flange 304 is connected and fixed with the second partition 201. In this way, the connection and fixation are performed along the entire circumferential direction, and the connection is more reliable. It can be known that the connection method between the water-catching cover plate 301 and the partition is not limited to flange connection, and direct connection through fasteners is also possible.

[0062] The water-catching cover plate 301 in this embodiment can be composed of multiple sections, that is, the water-catching cover plate 301 is divided into at least two sections in the circumferential direction, and finally spliced ​​together during installation. Such a configuration will not affect the water-catching and hydrophobic effect, and is also conducive to compensating the radial deformation difference between the first partition plate 101 and the second partition plate 201.

[0063] For example, the water-catching cover plate 301 can be divided into two parts in the circumferential direction. In this case, the water-catching cover plate 301 includes a first cover plate section and a second cover plate section. Figure 2 The diagram shows the first covering plate section, the first covering plate section and the second covering plate section are semicircular arc plates, the first covering plate section and the second covering plate section are butted together along the circumferential direction to form a complete water-catching covering plate 301, and the first flange 303 and the second flange 304 are also correspondingly provided as two parts butted together along the circumferential direction, which are correspondingly defined as the first flange section and the second flange section, as well as the first flange section and the second flange section. At this time, the first flange 303 and the second flange 304 are provided with dovetail protrusions at the first flange section and the second flange section corresponding to the first covering plate section, which are respectively Figure 2The first dovetail protrusion 3031 and the second dovetail protrusion 3041 shown in the figure are matched with the dovetail groove of the partition plate, as shown in FIG. Figure 2 As shown, the steam inlet side end face of the first partition 101 and the steam outlet side end face of the second partition 201 are both provided with dovetail grooves. The partition is generally also divided into two parts along the circumferential direction. One part of the partition can be defined as the first partition part, and the other part can be defined as the second partition part. The first partition part and the second partition part are semicircular arc-shaped. When installing, the first partition part of the first partition 101 and the second partition 201 can be put in place first. Specifically, the first partition part is arranged with the arc opening facing upward. At this time, the first flange part, the second flange part and the first cover plate part are already connected together. Then, the dovetail protrusions on the first flange part and the second flange part are embedded in the dovetail grooves of the corresponding partition part, and gradually slide in along the circumferential direction until the first cover plate part, the first flange part and the second flange part of the water-catching cover plate 301 are all installed in place. It can be seen that it is also possible to set a dovetail boss on the partition and a dovetail groove on the flange.

[0064] The installation methods of the first flange part and the second flange part are different, such as Fig.10 As shown, Fig.10 It is a schematic diagram of the connection between the first flange part 2 and the second flange part 2 and the partition.

[0065] At this time, the first flange part 2 and the second flange part 2 can be provided with convex stoppers, which are Fig.10 The first convex stop 3032 and the second convex stop 3043 shown in the figure match with the corresponding concave stop of the second partition. When installing, first put the second partition of the first partition 101 and the second partition 201 in place and fix them on the first partition, then drop the second cover plate section until the end face convex stops of the first flange section and the second flange section on both sides of the second cover plate section are pressed on the concave stop used for positioning of the second partition, and the convex stop and the concave stop are step structures, so that the convex stop and the concave stop can be overlapped in one direction, which is convenient for disassembling the second cover plate section and the second partition, and is convenient for replacement and maintenance.

[0066] When the convex stopper and the concave stopper are matched, the first flange 303 and the second flange 304 of the water-catching cover plate 301 can be fastened to the corresponding steam inlet side end surface of the first partition plate 101 and the steam outlet side end surface of the second partition plate 201 by using multiple screws 305 evenly distributed around the circumference. In order to prevent the hydrophobicity from scouring the heads of the screws 305, the first flange 303 and the second flange 304 can be provided with a recessed groove, such as Figure 2 , 10 As shown, the head of the screw 305 can lie in a recessed groove provided on the flange for protection.

[0067] Please continue to refer to Figure 3 , and combined with Fig.11 understand, Fig.11 for Figure 3 The view of the hydrophobic cover plate 302 along the Q direction, that is, Figure 3 Bottom view of the hydrophobic cover plate 302.

[0068] The water-catching device in this embodiment further includes an annular hydrophobic cover plate 302, which is used to be arranged on the inner side of the partition plate of the upstream stationary blade assembly in two adjacent stages of stationary blade assemblies, and in this embodiment, is arranged on the inner side of the second partition plate 201 as the second-last stage partition plate, and faces the shroud 501 of the moving blade assembly 500. The inner side of the hydrophobic cover plate 302 is provided with a plurality of hydrophobic grooves 302a distributed along the circumferential direction, and the hydrophobic grooves 302a are arranged obliquely relative to the circumferential direction of the hydrophobic cover plate 302, that is, the hydrophobic grooves 302a and the circumferential direction of the hydrophobic cover plate 301 have a non-right angle. It can be seen that the hydrophobic cover plate 302 has a substantially same structure as the above-mentioned water-catching cover plate 301, but does not have a through groove 301b. After the hydrophobic cover plate 302 is installed on the inner side of the partition of the stationary blade assembly, the hydrophobic groove 302a of the hydrophobic cover plate 302 has an angle β with the rotation direction of the moving blade 502. The rotation direction of the moving blade 502 is parallel to the circumferential direction. The rotation direction is a vector. Here, the angle β between the hydrophobic cover plate 302 and the rotation direction and the angle with the steam inlet direction are both acute angles. In this way, the hydrophobic groove 302a is inclined along the rotation direction of the moving blade 502, so that under the steam flow of the moving blade 502, the water vapor, water droplets, etc. near the periphery of the flow can flow along the hydrophobic groove 302a, and flow from the hydrophobic groove 302a to the water-catching cover plate 301, and then enter the through groove 301b and flow out of the flow. The angle β between the hydrophobic groove 302a and the rotation direction is the same as the angle α between the groove 301a and the rotation direction, and can also be selected to be about 30°. On the one hand, the inclination angle allows the collected accumulated water to flow toward the downstream water-catching cover plate 301. On the other hand, due to the inclined setting of the drain groove 302a, which also has an inclination angle with the axial direction, it can increase the resistance to the steam leaking from the shroud 501 of the moving blade assembly 500, thereby reducing steam leakage.

[0069] In this embodiment, the width y of the drain groove 302a and the width m of the groove 301a can be set to be the same, that is, 1mm-3mm is selected, the spacing x between adjacent drain grooves 302a and the spacing n between adjacent grooves 301a can be the same, for example, 1mm-3mm is selected, and the specific selection of the size of the drain groove 302a can be determined according to the water content ratio carried in the steam. The larger the water content ratio, the larger the width of the drain groove 302a can be set, and the smaller the spacing between each drain groove 302a can be set. Conversely, the smaller the water content ratio in the steam, the smaller the width of the drain groove 302a can be set, and the larger the spacing between each drain groove 302a can be set. The depth of the drain groove 302a can also be set with reference to the depth h of the groove 301a, which will not be repeated.

[0070] like Figure 3As shown, in the axial direction, one end of the hydrophobic cover plate 302 close to the water-catching cover plate 301 is an annular slope 302c, that is, the slope 302c is located on the steam outlet side of the hydrophobic cover plate 302. The hydrophobic grooves 302a are all connected to the slope 302c, and the hydrophobic grooves 302a can pass through the slope 302c, so that the slope 302c can drain the accumulated water in the hydrophobic grooves 302a into the water-catching cover plate 301, which is conducive to completely draining the accumulated water in all the hydrophobic grooves 302a. The steam inlet side of the hydrophobic cover plate 302 is provided with a third annular groove 302b that connects all the hydrophobic grooves 302a, which is conducive to the gathering of hydrophobic water.

[0071] The slope 302c of the hydrophobic cover plate 302 may be arranged to be flush with the inner surface of the water-catching cover plate 301 to reduce the resistance to steam flow. Figure 3 As shown in FIG. 1 , the inner annular surface 3042 of the second flange 304 on the steam inlet side of the water-catching cover plate 301 is flush with the slope surface 302c, and the inner annular surface 3042 of the second flange 304 is also flush with the inner side surface of the water-catching cover plate 301. After the water-catching cover plate 301 is installed, its inner side surface is also substantially flush with the outer peripheral surface of the flow passage, as shown in FIG. Figure 2 As shown, the inner surface of the water-catching cover plate 301 is flush with the inner annular surface of the first flange 303 and the inner surface of the first partition plate 101, thereby playing a good flow-guiding role and preventing additional eddy current losses from occurring.

[0072] The inner side of the second partition plate 201 may be provided with a dovetail groove, and the outer side of the hydrophobic cover plate 302 may be provided with a dovetail boss, and the two are plugged and positioned to connect the hydrophobic cover plate 302 to the second partition plate 201. This matching connection method does not occupy the setting area of ​​the hydrophobic groove 302a. Of course, the hydrophobic cover plate 302 is provided with a dovetail groove, and the inner side of the second partition plate 201 is provided with a dovetail boss. It can be known that the connection method of the hydrophobic cover plate 302 and the second partition plate 201 is not limited to this, for example, they can also be connected by fasteners.

[0073] This embodiment also provides a steam turbine, including the water capture device described in any of the above embodiments, which has the same technical effects and will not be discussed again.

[0074] like Figure 2 As shown, the first flange 303 and the second flange 304 at both ends of the water-catching cover plate 301 are respectively connected and fixed to the corresponding first baffle 101 and the second baffle 201. At this time, the outer annular surfaces of the first flange 303 and the second flange 304 can be set as inclined surfaces, so that they can cooperate with the corresponding baffles to form an annular drainage groove, that is, Figure 2 The first drainage groove a and the second drainage groove b are shown in the figure. Figure 2In the embodiment, the outer peripheral wall of the first baffle 101 near the steam inlet side forms a sharp angle and a V-shaped groove, which can be matched with the outer annular surface of the first flange 303 to deepen the depth of the V-shaped groove. The outer peripheral wall of the second baffle 201 near the steam outlet side is relatively flat, but the edge is also a slope to form a sharp angle, and the outer annular surface of the second flange 304 can also increase the depth of the slope, so that the first drainage groove a and the second drainage groove b can be formed. The first drainage groove a and the second drainage groove b can guide the water trapped by the water-catching cover plate 301 into the steam extraction chamber 400 below the cylinder, and at the same time prevent the water from rebounding back into the throughflow.

[0075] After research, it is found that when the water-catching cover plate 301 in this embodiment is not provided, when the liquid phase water reaches the sharp corner between the first baffle plate 101 and the second baffle plate 102 on the steam inlet side or the steam outlet side of the baffle plate, it will be torn and atomized again by the mainstream steam, resulting in a reduced hydrophobic effect. After the water-catching cover plate 301 is provided, the groove 301a provided on the inner side of the water-catching cover plate 301 can efficiently collect the accumulated water, and the surface tension of the liquid film attached to the water-catching cover plate 301 allows the liquid phase water to flow into the back of the water-catching cover plate 301 relatively smoothly through the through groove 301b on the water-catching cover plate 301. The back of the water-catching cover plate 301 is a space that will not be torn and atomized by the mainstream steam, thereby improving the effect of water-catching and hydrophobic, and achieving a better dehumidification purpose. Especially in the case of heat recovery steam extraction, heat recovery steam extraction can further improve the ability of liquid phase water to pass through the water-catching cover plate 301, and the hydrophobic efficiency can reach 46% when there is heat recovery steam extraction. Compared with the hydrophobic efficiency of a general steam turbine, which is only a few percent at most, the improvement is relatively large.

[0076] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. Water capture device of steam turbine, It is characterized in that The water-catching device comprises an annular water-catching cover plate, the water-catching cover plate is used to be arranged between the partition plates of two adjacent stages of stationary blade assemblies, the water-catching cover plate is provided with a plurality of through grooves distributed along the circumferential direction and penetrating along the inside and outside; a plurality of grooves are further provided on the inner side of the water-catching cover plate between two adjacent through grooves, the grooves are connected to the through grooves, and the grooves are arranged obliquely relative to the circumferential direction of the water-catching cover plate; The inner side of the water-catching cover plate is provided with a first annular groove on one axial side and a second annular groove on the other axial side; one end of the through groove is connected to the first annular groove, and the other end of the through groove is connected to the second annular groove; Along the axial direction, the groove located in the middle area between two adjacent through grooves is connected to one through groove at one end and connected to another adjacent through groove at the other end; the groove located in the end area on the steam inlet side or the end area on the steam outlet side between two adjacent through grooves is connected to one through groove at one end and connected to the corresponding first annular groove or the second annular groove at the other end.

2. The water capture device for a steam turbine according to claim 1, It is characterized in that The through groove extends from one axial side of the water-catching cover plate to the other axial side, and the extending direction of the through groove is perpendicular to the circumferential direction of the water-catching cover plate.

3. The water capture device for a steam turbine according to claim 2, It is characterized in that The water-catching cover plate is used to enclose a wall of the through groove, including a first side wall and a second side wall arranged opposite to each other in the circumferential direction, wherein the first side wall is perpendicular to the inner surface of the water-catching cover plate; The second side wall has an acute angle with the inner surface of the water-catching cover plate; or, the second side wall includes a second side wall inner section and a second side wall outer section distributed from the inside to the outside, the second side wall outer section has a first angle with the inner surface of the water-catching cover plate, the second side wall inner section has a second angle with the inner surface of the water-catching cover plate, the first angle is an acute angle, and the second angle is greater than the first angle and not greater than 90°.

4. The water capture device for a steam turbine according to claim 1, It is characterized in that The water-catching cover plate is an arched structure that is concave from the outside to the inside.

5. The water capture device for a steam turbine according to claim 1, It is characterized in that The radial dimension of the water-catching cover plate gradually increases in the axial direction, and the width of the through groove increases as the radial dimension increases.

6. The water capture device for a steam turbine according to any one of claims 1 to 5, It is characterized in that Flanges are provided on both sides of the water-catching cover plate along the axial direction, and the flanges are used to be connected and fixed with the corresponding partition plates.

7. The water capture device for a steam turbine according to claim 6, It is characterized in that The water-catching cover plate comprises a first cover plate section and a second cover plate section, wherein the first cover plate section and the second cover plate section are butted together along the circumferential direction to form the water-catching cover plate; The flange corresponds to a portion of the first cover plate section and the corresponding partition, one of which is provided with a dovetail protrusion and the other is provided with a dovetail groove matching the dovetail protrusion; or, the flange corresponds to a portion of the second cover plate section and the corresponding partition, one of which is provided with a convex stopper and the other is provided with a concave stopper matching the dovetail protrusion.

8. The water capture device for a steam turbine according to any one of claims 1 to 5, It is characterized in that It also includes an annular hydrophobic cover plate, which is used to be arranged on the inner side of the partition of the upstream static blade assembly in two adjacent stages of static blade assemblies and faces the shroud of the moving blade assembly; the inner side of the hydrophobic cover plate is provided with a plurality of circumferentially distributed hydrophobic grooves, and the hydrophobic grooves are inclined relative to the hydrophobic cover plate.

9. The water capture device for a steam turbine according to claim 8, It is characterized in that In the axial direction, the side of the hydrophobic cover plate close to the water-catching cover plate has an annular slope surface, and the hydrophobic grooves are all connected to the slope surface.

10. The water capture device for a steam turbine according to claim 9, It is characterized in that The slope surface is flush with the inner surface of the water-catching cover plate.

11. Steam turbine, It is characterized in that It comprises a moving blade assembly and a stationary blade assembly, and also comprises a water-catching device for a steam turbine as described in any one of claims 1 to 10, wherein the groove of the water-catching cover plate of the water-catching device has an acute angle with both the steam inlet direction and the rotation direction of the moving blade assembly.

12. The steam turbine according to claim 11, It is characterized in that The water-catching cover plate is provided with a first flange on one side along the axial direction, and a second flange on the other side along the axial direction, and the first flange and the second flange are respectively used to be connected and fixed with the corresponding partition; the outer annular surfaces of the first flange and the second flange are inclined surfaces, and cooperate with the corresponding partition to form an annular drainage groove.

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