An assembled double split-flow turbine nozzle chamber

Abstract

The utility model relates to a steam turbine technical field, concretely relates to a kind of assembly type double split-flow steam turbine nozzle chamber.The utility model provides an assembly type double split-flow steam turbine nozzle chamber, including cylinder, flow guide ring, two valve seat mounting pieces and two nozzles;The cylinder includes the upper cylinder and lower cylinder connected, the nozzle includes upper half nozzle and lower half nozzle, the flow guide ring includes upper ring and lower ring;The upper half nozzle is connected in the upper cylinder, and the lower half nozzle is connected in the lower cylinder;Two first partition ribs for separating chamber are integrally formed on the inner wall of the upper cylinder.The flow guide ring can be casted, heat treated and roughly processed separately, fully release casting stress and heat treatment stress, maximum reduce the distortion caused by uneven wall thickness and cooling rate difference.

Description

Technical Field

[0001] This utility model relates to the field of steam turbine technology, specifically to an assembled double-flow steam turbine nozzle chamber. Background Technology

[0002] Traditional industrial steam turbines are generally unidirectional flow turbines, with the nozzle chamber and cylinder cast as a single piece. Several mutually separated chambers are formed by ribs, and an arc-shaped slot for mounting nozzles is formed on one side of each chamber. However, the nozzle chamber of a dual-flow steam turbine requires a guide ring structure on its inner wall to divide and guide the steam flow. Furthermore, because the steam flow is split into two streams, arc-shaped slots for mounting nozzle assemblies need to be created on both sides of the nozzle chamber. If a single-piece casting design is also used, the following problems will arise:

[0003] (1) During the cooling process of large castings, the intermediate guide ring is prone to twisting and deformation due to differences in wall thickness and uneven cooling rate, which destroys the geometric symmetry of the design; (2) The inner surface of the guide ring is located in a closed cavity and cannot be machined (such as boring or grinding). It can only rely on the surface precision of the casting, which is difficult to meet the requirements of the steam flow channel for roughness, affecting the bidirectional uniform distribution of steam and causing friction leading to energy loss; (3) The guide ring is wrapped inside the casting. Conventional detection methods (such as X-ray and ultrasound) cannot effectively detect internal defects (porosity, shrinkage, cracks) due to structural obstruction; (4) The two side walls of the steam chamber along the axial direction are provided with arc-shaped slots, cutting off the continuous structure of the two side walls. The annular guide ring structure is only connected to the inner wall of the steam chamber by the partition, which significantly reduces the material bearing section and forms a stress concentration area. This causes the side wall bending stiffness and overall pressure bearing strength of the guide ring to decrease significantly when it is subjected to water pressure test or steam pressure. Utility Model Content

[0004] (I) The problem to be solved by this utility model is to solve the problems pointed out in the background art above.

[0005] (II) Technical Solution

[0006] A prefabricated dual-flow steam turbine nozzle chamber includes a cylinder, a guide ring, two valve seat mounting components, and two nozzles. The cylinder includes an upper cylinder and a lower cylinder connected to each other. The nozzle includes an upper nozzle and a lower nozzle. The guide ring includes an upper ring and a lower ring. The upper nozzle is engaged with the upper cylinder, and the lower nozzle is engaged with the lower cylinder. Two first ribs for separating the chambers are integrally formed on the inner wall of the upper cylinder, and two second ribs for separating the chambers are integrally formed on the inner wall of the lower cylinder. The upper ring and the two first ribs are detachably connected by a first connector, and the lower ring and the two second ribs are detachably connected by a second connector. The two valve seat mounting components are detachably installed between the guide ring and the cylinder, and the valve seats are mounted on the valve seat mounting components.

[0007] According to one embodiment of the present invention, the inner wall of the upper cylinder is provided with an arc groove for installing the upper half nozzle, and the inner wall of the lower cylinder is provided with an arc groove for installing the lower half nozzle.

[0008] The upper nozzle has a hook on its inner wall and the upper ring has a hook groove on its outer circumferential surface that matches the hook.

[0009] The lower nozzle has a hook on its inner wall and a hook groove on its outer circumference that matches the hook.

[0010] According to one embodiment of the present invention, the first connecting member includes a connecting plate and at least one third screw; at least one first threaded hole is provided on the circumferential surface of the upper ring opposite to the first partition rib; the connecting plate is slidably installed between the two nozzles; along the radial direction of the upper ring, the connecting plate is located between the first threaded hole and the first partition rib; the third screw is threaded into the first threaded hole; the connecting plate is pushed towards the first partition rib by the third screw, so that the connecting plate is tightly attached to the first partition rib.

[0011] According to one embodiment of the present invention, the second connecting member includes a connecting plate and at least one third screw; at least one second threaded hole is provided on the circumferential surface of the lower ring at a position opposite to the second partition rib; the connecting plate is slidably installed between the two nozzles; along the radial direction of the lower ring, the connecting plate is located between the second threaded hole and the second partition rib; the third screw is threadedly connected to the second threaded hole.

[0012] According to one embodiment of the present invention, a first slot corresponding to the first partition rib is provided on the outer peripheral surface of the upper ring, and the connecting plate of the first connector is inserted into the first slot of the upper ring; a first slot corresponding to the second partition rib is provided on the outer peripheral surface of the lower ring, and the connecting plate of the second connector is inserted into the first slot of the lower ring.

[0013] According to one embodiment of the present invention, the nozzle is provided with a plurality of limiting grooves, and the connecting plate is slidably installed between the limiting grooves of two of the nozzles.

[0014] According to one embodiment of the present invention, the upper ring and the lower ring are respectively provided with notches at both ends. When the upper ring and the lower ring are combined together, the two notches at the same end of the upper ring and the lower ring are combined to form a second slot. The bottom sides of the upper cylinder and the top sides of the lower cylinder are respectively provided with grooves. When the upper cylinder and the lower cylinder are assembled together, the two grooves on the same side of the upper cylinder and the lower cylinder are combined to form a retaining groove.

[0015] According to one embodiment of the present invention, the valve seat mounting component includes an upper partition plate, a lower partition plate, a valve seat sleeve, a plurality of second screws, and a clamping mechanism; the first ends of the upper partition plate and the lower partition plate are both inserted into the second slot of the guide ring, and the second ends of the upper partition plate and the lower partition plate are both inserted into the slot of the cylinder; one end of the upper partition plate is fixed to the notch of the upper ring by a second screw, and one end of the lower partition plate is fixed to the notch of the lower ring by a second bolt; the upper partition plate is located above the lower partition plate, the upper partition plate has a first circular hole, and the lower partition plate has a second circular hole, the first circular hole and the second circular hole being coaxial; the bottom surface of the upper partition plate has a circular groove, the circular groove being coaxial with the first circular hole, and the diameter of the circular groove being larger than the diameter of the first circular hole; the clamping mechanism is used to fasten the valve seat sleeve to the inner top wall of the circular groove.

[0016] According to one embodiment of the present invention, the clamping mechanism includes a first screw and a limiting pressure plate. A groove adapted to the limiting pressure plate is formed on the circumferential surface of the valve seat sleeve near its bottom. One end of the limiting pressure plate is inserted into the groove. The limiting pressure plate is fixed to the upper partition plate by the first screw.

[0017] According to one embodiment of the present invention, a pressing groove is provided on the inner wall of both the upper and lower nozzles. The upper partition plate is pressed against the inner top wall of the pressing groove of the upper nozzle by a pressing member, and the lower partition plate is pressed against the inner bottom wall of the pressing groove of the lower nozzle by a pressing member.

[0018] The beneficial effects of this utility model are:

[0019] First, the guide ring can be cast, heat treated and rough machined separately, which fully releases casting stress and heat treatment stress, and minimizes torsional deformation caused by uneven wall thickness and different cooling rates.

[0020] Secondly, as independent upper and lower ring components, the guide ring can be machined separately (such as turning, boring, grinding, and polishing) before assembly, which can precisely control the profile accuracy and surface roughness of the guide ring surface, significantly reduce the friction loss of steam flow, and improve the efficiency of the steam turbine.

[0021] Third, key components such as flow guide rings and valve seat mounting parts can be used as independent parts before assembly, which facilitates comprehensive inspection using conventional non-destructive testing methods (such as X-ray, ultrasonic, and penetrant testing). This avoids the obstruction of testing rays and interference of ultrasonic wave propagation by the traditional closed chamber structure, and can effectively detect defects such as porosity, shrinkage, and cracks inside the casting, ensuring that the quality of the parts meets the requirements.

[0022] Fourth, breaking down large and complex integral castings into multiple small and medium-sized components greatly reduces the difficulty and cost of casting, machining, and heat treatment, and improves manufacturing feasibility, making it particularly suitable for large steam turbine units;

[0023] Fifth, the nozzle chamber is designed as an assembled structure, and the force borne by the original side wall ribs can be borne by the entire nozzle ring, which solves the problem of deformation and insufficient pressure bearing caused by only the ribs as the load-bearing section in the one-piece casting design. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 A perspective view provided for an embodiment of this utility model;

[0026] Figure 2 A longitudinal sectional view of a steam turbine provided for an embodiment of this utility model;

[0027] Figure 3 A transverse sectional view of the turbine blade provided in an embodiment of this utility model;

[0028] Figure 4 Provided for the embodiments of this utility model Figure 3 Sectional view of AA;

[0029] Figure 5 Provided for the embodiments of this utility model Figure 3 Enlarged view of section B;

[0030] Figure 6 A schematic diagram showing the lower partition plate installed on the lower cylinder according to an embodiment of this utility model;

[0031] Figure 7 Provided for the embodiments of this utility model Figure 6 Enlarged view of section C;

[0032] Figure 8 A schematic diagram showing the connection of the upper partition plate, lower partition plate, upper nozzle, and lower nozzle provided in an embodiment of this utility model;

[0033] Figure 9 A perspective view of the flow guide ring provided in an embodiment of this utility model;

[0034] Figure 10A structural diagram of the upper partition plate provided in an embodiment of this utility model;

[0035] Figure 11 A structural diagram of the lower partition plate provided in an embodiment of this utility model;

[0036] Figure 12 A structural diagram of the valve seat sleeve provided in an embodiment of this utility model;

[0037] Figure 13 This is a structural diagram of the connecting plate provided in an embodiment of the present utility model.

[0038] Icons: 1. Upper cylinder; 101. First baffle; 102. Chamber 1; 103. Chamber 2; 104. Chamber 3; 105. First valve seat port; 106. Second valve seat port; 107. Third valve seat port; 108. Fourth valve seat port; 109. Fifth valve seat port; 2. Lower cylinder; 201. Second baffle; 202. Chamber 4; 203. Chamber 5; 204. Hollow chamber; 3. Guide ring; 301. Hook groove; 302. First slot; 303. Second slot; 4. Nozzle; 401, Hook; 5, Valve seat four; 6, Valve seat five; 7, First connecting piece; 701, Connecting plate; 702, T-slot; 8, Upper partition plate; 801, First step groove; 802, First mounting hole; 803, Arc groove; 9, Lower partition plate; 901, Second step groove; 902, Second mounting hole; 10, Valve seat sleeve; 1001, Groove; 11, First screw; 12, Limiting pressure plate; 13, Second screw; 14, Third screw; 15, Fixing pressure plate; 16, Fourth screw. Detailed Implementation

[0039] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0040] like Figures 1-13As shown, one embodiment of this utility model provides an assembled dual-flow turbine nozzle chamber, including a cylinder, a guide ring 3, two valve seat mounting components, and two nozzles 4; the cylinder includes an upper cylinder 1 and a lower cylinder 2 connected to each other, the nozzle 4 includes an upper nozzle and a lower nozzle, and the guide ring 3 includes an upper ring and a lower ring; the upper nozzle is snapped into the upper cylinder 1, and the lower nozzle is snapped into the lower cylinder 2; two first ribs 101 for separating the chambers are integrally formed on the inner wall of the upper cylinder 1, and two second ribs 201 for separating the chambers are integrally formed on the inner wall of the lower cylinder 2; the upper ring and the two first ribs 101 are detachably connected by a first connector 7, and the lower ring and the two second ribs 201 are detachably connected by a second connector; the two valve seat mounting components are detachably installed between the guide ring 3 and the cylinder, and the valve seats are installed on the valve seat mounting components.

[0041] In this embodiment, as Figure 1 As shown, the cylinder includes an upper cylinder 1 and a lower cylinder 2. The end faces of the upper cylinder 1 and the lower cylinder 2 are connected by multiple fastening bolts to form a cylinder.

[0042] like Figure 2 As shown, there are two nozzles 4, each consisting of a semi-circular upper nozzle and a lower nozzle. A nozzle groove, which is semi-circular, is formed on the inner wall of the upper cylinder 1 on both sides of its vertical center line; similarly, a nozzle groove is formed on the inner wall of the lower cylinder 2 on both sides of its vertical center line. The upper nozzle is fitted into the nozzle groove of the upper cylinder 1, and the lower nozzle is fitted into the nozzle groove of the lower cylinder 2.

[0043] In this embodiment, as Figure 9 As shown, the guide ring 3 consists of two semi-circular upper and lower rings. A hook groove 301 is provided on each side of the outer circumference of the upper ring, and similarly, a hook groove 301 is provided on each side of the outer circumference of the lower ring. It should be noted that the hook groove 301 on the outer circumference of the upper ring has the same circumference as the upper ring, and the hook groove 301 on the outer circumference of the lower ring has the same circumference as the lower ring. When the upper and lower rings are assembled together, the two opposing hook grooves 301 on the upper and lower rings form a circular groove.

[0044] Furthermore, such as Figure 2 and Figure 4 As shown, a hook 401 is provided on the inner wall of the upper nozzle, and similarly, a hook 401 is also provided on the inner wall of the lower nozzle. The upper ring and the upper nozzle, as well as the lower ring and the lower nozzle, are connected by the hook 401 and the hook groove 301.

[0045] Specifically, when installing the upper ring, bring the end of the upper ring close to the hook 401 of the upper nozzle, aligning one end of the hook groove 301 of the upper ring with the hook 401 of the upper nozzle. Then rotate the upper ring so that the hook 401 of the upper nozzle screws into the hook groove 301 of the upper ring. This allows for a quick connection between the upper nozzle and the upper ring, facilitating installation and disassembly. The connection steps between the lower nozzle and the lower ring are as described above and will not be repeated here.

[0046] In some embodiments, the hook 401 is arc-shaped with an L-shaped cross-section, and the perimeter of the hook 401 is the same as the perimeter of the upper or lower nozzle. It should be noted that the L-shaped cross-section of the hook 401 can improve the connection strength between the nozzle 4 and the guide ring 3, making it less likely for the nozzle 4 and the guide ring 3 to detach.

[0047] In this embodiment, as Figure 3 As shown, one valve seat mounting component is detachably installed between the left side of the guide ring 3 and the inner wall of the left side of the cylinder, and another valve seat mounting component is detachably installed between the right side of the guide ring 3 and the inner wall of the right side of the cylinder. Valve seat four 5 and valve seat five 6 are respectively installed on the two valve seat mounting components. Due to the presence of the guide ring 3, the first partition 101, the second partition 201, and the two valve seat mounting components, chambers 102, 103, 104, 202, 203, and 204 are formed inside the turbine. Chamber 102 is located between the two first partitions 101. Valve seat four 5 and chamber 203 are connected, and valve seat five 6 is connected to chamber 202. Chamber 204 is located between the two first partitions 101.

[0048] Five valve seat ports are formed on the top of the upper cylinder 1. For ease of description, these five valve seat ports are named in sequence as the first valve seat port 105, the second valve seat port 106, the third valve seat port 107, the fourth valve seat port 108, and the fifth valve seat port 109.

[0049] Specifically, chamber 102 is connected to the third valve seat port 107. The first valve seat port 105 and the second valve seat port 106 are both located above chamber 2 103, and the fourth valve seat port 108 and the fifth valve seat port 109 are both located above chamber 3 104. The top of valve seat 5 6 is fitted into the first valve seat port 105, and the top of valve seat 4 5 is fitted into the fifth valve seat port 109.

[0050] In this embodiment, the first connector 7 includes a connecting plate 701 and at least one third screw 14.

[0051] like Figure 9As shown, four first slots 302 are formed on the outer circumferential surface of the guide ring 3, two of which are located on the upper ring and the other two on the lower ring. The two first slots 302 on the upper ring are respectively opposite to two first partitions 101 for insertion of the first partitions 101. The two first slots 302 on the lower ring are respectively opposite to two second partitions 201 for insertion of the second partitions 201. Furthermore, two first threaded holes are formed on the inner wall of the first slots 302 on the upper ring, and two second threaded holes are formed on the inner wall of the first slots 302 on the lower ring.

[0052] like Figure 4 As shown, the connecting plate 701 is a rectangular plate, which is slidably installed between the two nozzles 4. Along the radial direction of the upper ring, the connecting plate 701 is located between the first slot 302 and the first partition 101. Two T-shaped grooves 702 are opened at one end of the connecting plate 701 facing the guide ring 3. Figure 4 As shown, the end of the third screw 14 has a T-shaped columnar structure that is adapted to the T-slot 702.

[0053] In some embodiments, a limiting groove is formed on the nozzle 4 along the radial direction of the nozzle 4, and the two ends of the connecting plate 701 are slidably fitted into the limiting grooves of the two nozzles 4. In this way, when the third screw 14 pushes the connecting plate 701 to move towards the first rib 101, the limiting groove can limit and guide the connecting plate 701, preventing the connecting plate 701 from shifting.

[0054] It should be noted that after assembling the upper ring of the guide ring 3 onto the two upper nozzles, the upper ring and the two upper nozzles are removed from the upper cylinder 1. Then, the third screw 14 is suspended in the T-slot 702 of the connecting plate 701. The connecting plate 701 is then placed between the two upper nozzles, with both sides of the connecting plate 701 inserted into the limiting slots of the two upper nozzles. The connecting plate 701 is then pushed so that the end of the third screw 14 on the connecting plate 701 is close to the first threaded hole of the upper ring. The third screw 14 is then tightened with a tool. The third screw 14 is threadedly connected to the first threaded hole of the upper ring and gradually moves downward toward the upper ring until the bottom end of the third screw 14 passes through the first threaded hole of the upper ring.

[0055] Subsequently, the upper nozzle, upper ring, and connecting plate 701 are reassembled into the upper cylinder 1, with the two connecting plates 701 aligned with the two first partitions 101 inside the upper cylinder 1. Then, the third screw 14 is rotated using a tool, moving it closer to the first partition 101, thereby pushing the connecting plates 701 closer to the first partition 101 until they are firmly pressed against it. Later, when disconnecting the upper ring of the guide ring 3 from the first partition 101, simply loosen the third screw 14. Because the T-shaped columnar structure at the end of the third screw 14 engages in the T-groove 702 of the connecting plate 701, the third screw 14 pulls the connecting plate 701 away from the first partition 101, thus removing the connection plate 701 from the first partition 101. This allows for a quick connection between the upper ring of the guide ring 3 and the first partition 101, and subsequent contact connections are also very convenient.

[0056] Since the two sides of the connecting plate 701 are respectively limited by the limiting grooves of the two upper nozzles, and one end of the connecting plate 701 along the radial direction of the nozzle 4 is inserted into the first slot 302 of the upper ring of the guide ring 3, all three sides of the connecting plate 701 are limited, which can greatly improve the stability of the connecting plate 701. In addition, the limiting grooves of the upper nozzles can also guide the connecting plate 701.

[0057] In this embodiment, as Figure 3 As shown, the two second partitions 201 on the inner wall of the lower cylinder 2 are connected to the lower ring of the guide ring 3 by a second connector. The second connector and the first connector 7 have the same structure. Since the upper ring and the first partition 101, as well as the lower ring and the second partition 201, are connected by the aforementioned connecting plate 701 and the third screw 14, to avoid redundancy, the connection method of the lower ring and the second partition 201 will not be described in detail here. For details, please refer to the connection method between the upper ring and the first partition 101.

[0058] In this embodiment, as Figure 9 As shown, the upper ring and the lower ring have notches at both ends. When the upper and lower rings are joined together, the two notches at the same end of the upper and lower rings merge to form a second slot 303. That is, along the midpoint of the guide ring 3, second slots 303 are formed on both sides of the outer periphery of the guide ring 3.

[0059] like Figure 3As shown, grooves are provided on both sides of the bottom of the upper cylinder 1 and on both sides of the top of the lower cylinder 2. Specifically, the grooves on the upper cylinder 1 are located on the inner wall of the upper cylinder 1 near its bottom, and the grooves on the lower cylinder 2 are located on the inner wall of the lower cylinder 2 near its top. When the upper cylinder 1 and the lower cylinder 2 are assembled together, the two grooves on the same side of the upper cylinder 1 and the lower cylinder 2 merge together to form a slot. The center of this slot is located on the turbine's split plane, that is, the grooves on the upper cylinder 1 and the lower cylinder 2 are symmetrical about the turbine's horizontal split plane.

[0060] In this embodiment, specifically, such as Figure 3 As shown, one valve seat mounting component is installed between the second slot 303 on the left side of the guide ring 3 and the slot on the inner wall of the left side of the cylinder, and another valve seat mounting component is installed between the second slot 303 on the right side of the guide ring 3 and the slot on the inner wall of the right side of the cylinder. Valve seat four 5 is installed on the valve seat mounting component on the right side of the guide ring 3, and the top end of valve seat four 5 extends into the fifth valve seat port 109. Valve seat four 5 is located in the third chamber 104 and is connected to the fifth chamber 203. Valve seat five 6 is located in the second chamber 103 and is installed on the valve seat mounting component located on the left side of the guide ring 3. The top end of valve seat five 6 extends into the first valve seat port 105, and valve seat five 6 is connected to the fourth chamber 202.

[0061] In some embodiments, such as Figure 5 As shown, the valve seat mounting assembly includes an upper partition plate 8, a lower partition plate 9, a valve seat sleeve 10, multiple second screws 13, and a clamping mechanism. Both the upper partition plate 8 and the lower partition plate 9 are rectangular plates. Figure 10 As shown, a first circular hole is formed on the upper partition plate 8, and a circular groove is formed on the upper partition plate 8. The circular groove is coaxial with the first circular hole, and the diameter of the circular groove is larger than the diameter of the first circular hole. Figure 11 As shown, a second circular hole is provided on the lower partition plate 9, and the diameter of the second circular hole is smaller than the diameter of the first circular hole.

[0062] Furthermore, a first mounting hole 802 and a second mounting hole 902 are respectively provided on the same side of the upper partition plate 8 and the lower partition plate 9. In addition, screw holes are respectively provided on the inner top wall and inner bottom wall of the second slot 303 of the guide ring 3.

[0063] Thus, when installing the upper partition plate 8, both ends of the upper partition plate 8 can be inserted into the notch of the upper ring and the groove of the upper cylinder 1 respectively, so that the first mounting hole 802 at the end of the upper partition plate 8 and the screw hole in the notch of the upper ring are aligned. Then, the second screw 13 is inserted into the first mounting hole 802 at the end of the upper partition plate 8 and tightened, thus achieving quick installation of the upper partition plate 8.

[0064] When installing the lower partition plate 9, insert both ends of the lower partition plate 9 into the notch of the lower ring and the groove of the lower cylinder 2 respectively. Then, use the second screw 13 to insert into the second mounting hole 902 at the end of the lower partition plate 9 and tighten it.

[0065] In this embodiment, the second screw 13 is a countersunk screw, which ensures that the upper partition plate 8 and the lower partition plate 9 can fit together.

[0066] In this embodiment, as Figure 12 As shown, the valve seat sleeve 10 includes an integrally formed inner tube and an outer ring. The lower surfaces of the inner tube and the outer ring are flush, and the length of the outer ring is less than the length of the inner tube.

[0067] In this embodiment, as Figure 5 As shown, the clamping mechanism is used to fix the valve seat sleeve 10 to the upper partition plate 8. Specifically, the clamping mechanism includes a first screw 11 and a limiting pressure plate 12. Figure 10 As shown, an arc groove 803 is provided on the upper partition plate 8, and the arc groove 803 is connected to the circular groove of the upper partition plate 8.

[0068] like Figure 12 As shown, a groove 1001 adapted to the limiting pressure plate 12 is provided on the circumferential surface of the outer ring of the valve seat sleeve 10, and a threaded hole matching the first screw 11 is provided in the arc groove 803 of the upper partition plate 8.

[0069] like Figure 5 As shown, during the actual installation of the valve seat sleeve 10, the limiting pressure plate 12 is first inserted into the groove 1001 of the valve seat sleeve 10. Then, the valve seat sleeve 10 is passed through the first circular hole on the upper partition plate 8, and the outer ring of the valve seat sleeve 10 fits against the circular groove of the upper partition plate 8. At this time, the limiting pressure plate 12 is located in the arc groove 803 of the upper partition plate 8. Then, the first screw 11 is passed through the hole on the limiting pressure plate 12, so that the first screw 11 enters the threaded hole of the arc groove 803 of the upper partition plate 8. Finally, the first screw 11 is tightened to fix the valve seat sleeve 10 on the upper partition plate 8.

[0070] In this embodiment, as Figure 10 and Figure 11 As shown, a first step groove 801 is provided on both sides of the upper partition plate 8 in the width direction, and a second step groove 901 is provided on both sides of the lower partition plate 9 in the width direction.

[0071] Furthermore, such as Figure 6 , Figure 7 and Figure 8 As shown, two nozzles are formed on the split surface of the upper nozzle.

[0072] Two clamping grooves are located at both ends of the upper nozzle, and screw holes are formed on the inner top wall of the two clamping grooves. Two clamping grooves are formed on the middle surface of the lower nozzle, located at both ends of the lower nozzle, and two screw holes are formed on the inner bottom wall of the two clamping grooves. The two ends of the upper partition plate 8 are fixed to the inner top wall of the clamping groove of the upper nozzle by clamping members, and the two ends of the lower partition plate 9 are fixed to the inner bottom wall of the clamping groove of the lower nozzle by clamping members.

[0073] In some embodiments, the clamping element is such as Figure 8 As shown, it includes a fixed pressure plate 15 and a fourth screw 16, and the fixed pressure plate 15 is provided with a countersunk hole.

[0074] This section uses the installation of the lower partition plate 9 as an example. When connecting the lower partition plate 9 to the lower half nozzle, after placing the lower partition plate 9 onto the clamping groove of the lower half nozzle, place the fixing plate 15 onto the clamping groove of the lower half nozzle, ensuring that the end of the fixing plate 15 presses against the second stepped groove 901 of the lower partition plate 9. Then, insert the fourth screw 16 into the countersunk hole of the fixing plate 15 and tighten it. The fourth screw 16 is threaded into the screw hole of the clamping groove of the lower half nozzle. The end of the fourth screw 16 presses down on the fixing plate 15. At the same time, since the fixing plate 15 acts on the second stepped groove 901 of the lower partition plate 9, it also presses down on the lower partition plate 9, thus fixing the lower partition plate 9 onto the lower half nozzle. Since the principle of installing the upper partition plate 8 onto the upper half nozzle is the same as the principle of installing the lower partition plate 9 onto the lower half nozzle, it will not be described here to avoid redundancy.

[0075] The specific assembly process is as follows:

[0076] Steam turbine assembly:

[0077] The first step is to pre-install the valve seat assembly (valve seat one to valve seat five 6) into the corresponding valve seat ports of the steam turbine casing 1, and then invert the upper cylinder.

[0078] The second step is to place the upper nozzle into the nozzle groove of the upper cylinder 1, align the upper ring of the guide ring 3 with the hook 401 of the upper nozzle, and then rotate the upper ring to install the upper ring onto the upper nozzle.

[0079] Third, attach both ends of the upper partition plate 8 to the groove on the split surface of the upper cylinder 1 and the notch on the end face of the upper ring of the guide ring 3, respectively. Then, use the second screw 13 to fix one end of the upper partition plate 8 that extends into the upper ring to the upper ring of the guide ring 3. Then, remove the assembled upper nozzle, the upper ring of the guide ring 3, and the upper partition plate 8 from the upper cylinder 1.

[0080] Fourth step, the third screw 14 is suspended in the T-slot 702 of the connecting plate 701. Then the connecting plate 701 is placed between the two upper nozzles, and the two sides of the connecting plate 701 are inserted into the limiting slots of the two upper nozzles. Then the connecting plate 701 is pushed so that the end of the third screw 14 on the connecting plate 701 is close to the first threaded hole of the upper ring. Then the third screw 14 is tightened with a tool. The third screw 14 is threadedly connected to the first threaded hole of the upper ring and gradually moves downwards towards the upper ring until the bottom end of the third screw 14 passes through the first threaded hole of the upper ring.

[0081] The fifth step is to put the assembled upper nozzle, the upper ring of the guide ring 3, and the two connecting plates 701 back into the nozzle slot in the upper cylinder 1.

[0082] The sixth step is to insert the limiting pressure plate 12 into the groove 1001 of the valve seat sleeve 10, and then put the two valve seat sleeves 10 onto the valve seat 4 5 and the valve seat 5 6 respectively. At this time, the valve seat sleeve 10 falls on the inner bottom wall of the circular groove of the upper partition plate 8, and the limiting pressure plate 12 enters the arc groove 803 of the upper partition plate 8. Then, screw in the first screw 11 to fix the limiting pressure plate 12 on the upper partition plate 8, thereby fastening the valve seat sleeve 10 on the upper partition plate 8.

[0083] Step 7: Use the fixing plate 15 and the fourth screw 16 to fix the upper partition plate 8 to the upper nozzle.

[0084] The eighth step is to finally tighten the third screw 14 on the upper half ring so that the connecting plate 701 presses against the first rib 101 on the inner wall of the upper cylinder 1.

[0085] Steam turbine assembly:

[0086] First, place the lower nozzle into the nozzle groove of the lower cylinder 2, align the lower ring of the guide ring 3 with the hook 401 of the lower nozzle, and then rotate the lower ring to install the lower ring onto the lower nozzle.

[0087] The second step involves attaching both ends of the lower partition plate 9 to the groove on the split surface of the lower cylinder 2 and the notch on the end face of the lower ring of the guide ring 3, respectively. Then, using the second screw 13, one end of the lower partition plate 9 that extends into the lower ring is fixed to the lower ring of the guide ring 3. Finally, the assembled lower half nozzle, the lower ring of the guide ring 3, and the lower partition plate 9 are removed from the lower cylinder 2 as a whole.

[0088] The third step is to use the third screw 14 to fix the two connecting plates 701 into the first slot 302 of the lower ring of the guide ring 3.

[0089] The fourth step is to put the assembled lower nozzle, the lower ring of the guide ring 3, and the connecting plate 701 back into the nozzle slot.

[0090] Fifth step, use the fixing plate 15 and the fourth screw 16 to fix the lower partition plate 9 to the lower half nozzle.

[0091] Step 7: Finally, tighten the third screw 14 to make the connecting plate 701 press against the second partition 201.

[0092] After the upper and lower steam turbines are assembled, the upper cylinder 1 is placed on the lower cylinder 2, and finally the upper cylinder 1 and the lower cylinder 2 are fixed together with bolts.

[0093] In summary, this prefabricated double-flow steam turbine nozzle chamber has the following advantages:

[0094] First, the guide ring 3 can be cast, heat treated and rough machined independently, fully releasing casting stress and heat treatment stress, and minimizing torsional deformation caused by uneven wall thickness and different cooling rates.

[0095] Secondly, as independent upper and lower ring components, the guide ring 3 can be machined separately (such as turning, boring, grinding, and polishing) before assembly. This allows for precise control of the profile accuracy and surface roughness of the guide ring 3, significantly reducing frictional losses in steam flow and improving turbine efficiency.

[0096] Third, key components such as the flow guide ring 3 and valve seat mounting parts can be used as independent parts before assembly, which facilitates comprehensive inspection using conventional non-destructive testing methods (such as X-ray, ultrasonic, and penetrant testing). This avoids the obstruction of testing rays and interference of ultrasonic wave propagation by the traditional closed chamber structure, and can effectively detect defects such as porosity, shrinkage, and cracks inside the casting, ensuring that the quality of the components meets the requirements.

[0097] Fourth, breaking down large and complex integral castings into multiple small and medium-sized components greatly reduces the difficulty and cost of casting, machining, and heat treatment, and improves manufacturing feasibility, making it particularly suitable for large steam turbine units.

[0098] Fifth, the nozzle chamber is designed as an assembled structure, and the force borne by the original side wall ribs can be borne by the entire ring of nozzles 4, which solves the problem of deformation and insufficient pressure bearing caused by only the ribs as the bearing section in the one-piece casting design.

[0099] In the description of this utility model, it should be noted that the terms "upper" and "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0100] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0101] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A prefabricated double-flow steam turbine nozzle chamber, characterized in that, The system includes a cylinder, a guide ring (3), two valve seat mounting pieces, and two nozzles (4); the cylinder includes an upper cylinder (1) and a lower cylinder (2) connected to each other, the nozzle (4) includes an upper nozzle and a lower nozzle, and the guide ring (3) includes an upper ring and a lower ring; the upper nozzle is engaged in the upper cylinder (1), and the lower nozzle is engaged in the lower cylinder (2); two first ribs (101) for separating chambers are integrally formed on the inner wall of the upper cylinder (1), and two second ribs (201) for separating chambers are integrally formed on the inner wall of the lower cylinder (2); the upper ring and the two first ribs (101) are detachably connected by a first connector, and the lower ring and the two second ribs (201) are detachably connected by a second connector; the two valve seat mounting pieces are detachably installed between the guide ring (3) and the cylinder, and the valve seats are installed on the valve seat mounting pieces.

2. An assembled double-flow steam turbine nozzle chamber according to claim 1, characterized in that The inner wall of the upper cylinder (1) is provided with a semi-circular groove for installing the upper half nozzle, and the inner wall of the lower cylinder (2) is provided with a semi-circular groove for installing the lower half nozzle. The upper nozzle has a hook on its inner wall and the upper ring has a hook groove (301) that matches the hook. The lower nozzle has a hook on its inner wall and a hook groove (301) on its outer circumferential surface that is adapted to the hook.

3. An assembled double-flow steam turbine nozzle chamber according to claim 2, characterized in that The first connector includes a connecting plate (701) and at least one third screw (14); at least one first threaded hole is provided on the circumferential surface of the upper ring opposite to the first partition (101); the connecting plate (701) is slidably mounted between the two nozzles (4); along the radial direction of the upper ring, the connecting plate (701) is located between the first threaded hole and the first partition (101); the third screw (14) is threaded into the first threaded hole; the connecting plate (701) is pushed towards the first partition (101) by the third screw (14) so ​​that the connecting plate (701) is tightly attached to the first partition (101).

4. An assembled double-flow steam turbine nozzle chamber according to claim 3, characterized in that The second connector includes a connecting plate (701) and at least one third screw (14); at least one second threaded hole is provided on the circumferential surface of the lower ring opposite to the second partition (201); the connecting plate (701) is slidably installed between the two nozzles (4); along the radial direction of the lower ring, the connecting plate (701) is located between the second threaded hole and the second partition (201); the third screw (14) is threaded into the second threaded hole.

5. An assembled double-flow steam turbine nozzle chamber according to claim 4, characterized in that The outer circumferential surface of the upper ring is provided with a first slot (302) corresponding to the first partition rib (101) one by one, and the connecting plate (701) of the first connector is inserted into the first slot (302) of the upper ring; the outer circumferential surface of the lower ring is provided with a first slot (302) corresponding to the second partition rib (201) one by one, and the connecting plate (701) of the second connector is inserted into the first slot (302) of the lower ring.

6. An assembled double-flow steam turbine nozzle chamber according to claim 5 or 4, characterized in that The nozzle (4) is provided with multiple limiting grooves, and the connecting plate (701) is slidably installed between the limiting grooves of two nozzles (4).

7. An assembled double-flow steam turbine nozzle chamber according to claim 6, characterized in that The upper ring and the lower ring are provided with notches at both ends. When the upper ring and the lower ring are combined, the two notches at the same end of the upper ring and the lower ring are combined to form a second slot (303). The bottom sides of the upper cylinder (1) and the top sides of the lower cylinder (2) are provided with grooves. When the upper cylinder (1) and the lower cylinder (2) are assembled together, the two grooves on the same side of the upper cylinder (1) and the lower cylinder (2) are combined to form a slot.

8. An assembled double-flow steam turbine nozzle chamber according to claim 7, characterized in that The valve seat mounting component includes an upper partition plate (8), a lower partition plate (9), a valve seat sleeve (10), multiple second screws (13), and a clamping mechanism; the first ends of the upper partition plate (8) and the lower partition plate (9) are both inserted into the second slot (303) of the guide ring (3), and the second ends of the upper partition plate (8) and the lower partition plate (9) are both inserted into the slot of the cylinder; one end of the upper partition plate (8) is fixed to the notch of the upper ring by the second screws (13), and one end of the lower partition plate (9) is fixed to the notch of the upper ring by the second screws (13). The second screw (13) is fixed in the notch of the lower ring; the upper partition plate (8) is located above the lower partition plate (9), the upper partition plate (8) has a first circular hole, the lower partition plate (9) has a second circular hole, the first circular hole and the second circular hole are coaxial; the bottom surface of the upper partition plate (8) has a circular groove, the circular groove is coaxial with the first circular hole, and the diameter of the circular groove is larger than the diameter of the first circular hole; the clamping mechanism is used to fasten the valve seat sleeve (10) to the inner top wall of the circular groove.

9. An assembled double-flow steam turbine nozzle chamber according to claim 8, characterized in that The clamping mechanism includes a first screw (11) and a limiting pressure plate (12). The valve seat sleeve (10) has a groove (1001) on its circumferential surface near its bottom that is adapted to the limiting pressure plate (12). One end of the limiting pressure plate (12) is inserted into the groove (1001). The limiting pressure plate (12) is fixed to the upper partition plate (8) by the first screw (11).

10. An assembled double-flow steam turbine nozzle chamber according to claim 9, characterized in that Both the upper and lower nozzles have clamping grooves on their inner walls. The upper partition plate (8) is clamped to the inner top wall of the clamping groove of the upper nozzle by a clamping member, and the lower partition plate (9) is clamped to the inner bottom wall of the clamping groove of the lower nozzle by a clamping member.

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