A pressure-reducing valve circuit structure at a pipeline valve

Abstract

This invention relates to the field of nuclear power plant turbine reheat piping technology, specifically to a pressure-reducing valve circuit structure at a pipeline valve, comprising: a pressure-reducing circuit pipe, a guide impeller assembly, a drive assembly, and two steam regulating valves. When the upstream and downstream pressure difference at the connection port between the pressure-reducing valve assembly and the pressure-reducing circuit pipe drives the valve core of the pressure-reducing valve assembly to open, the valve core triggers the switching component of the drive assembly to open, and the drive assembly operates to drive the guide impeller assembly. When there is no upstream and downstream pressure difference at the connection port between the pressure-reducing valve assembly and the pressure-reducing circuit pipe, the valve core closes, the switching component closes, and the drive assembly stops operating. This device effectively reduces eddy currents in the flow field, thereby improving the pressure-reducing efficiency of the pressure-reducing valve assembly; ultimately ensuring the stable operation of the pressure-reducing valve circuit and the optimization of steam flow, thereby improving the operating efficiency and safety of the entire steam system.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant turbine reheat pipeline technology, specifically to a pressure-reducing valve circuit structure at a pipeline valve. Background Technology

[0002] The reheat piping of the turbine in a conventional island nuclear power plant is a key component of the secondary loop system. In a nuclear power plant, steam is generated in the nuclear island and then enters the turbine in the conventional island to perform work. To improve the efficiency of steam in the turbine, a portion of the exhaust steam from the high-pressure cylinder is sent to the reheater for reheating; this process is achieved through the reheat piping. This allows for more efficient utilization of the steam's thermal energy, thereby improving the turbine's thermal efficiency and power generation efficiency. Furthermore, the reheat piping helps reduce the humidity of the turbine exhaust steam, minimizing erosion of the turbine blades and extending equipment life, thus ensuring the stable operation of the nuclear power plant.

[0003] The reheat piping system typically includes a cold reheat section and a hot reheat section steam system. The cold reheat steam system refers to the steam piping and branch pipes from the exhaust port of the high-pressure cylinder of the steam turbine to the inlet header of the boiler reheater; the hot reheat steam system refers to the steam piping and branch pipes from the outlet header of the boiler reheater to the inlet valve of the intermediate-pressure cylinder of the steam turbine. These two systems together constitute the complete system of the steam turbine reheat piping.

[0004] In the actual operation of a nuclear power plant, the high-temperature, high-pressure steam generated by the MSR (Main Steam Reheater) must be smoothly introduced into the turbine for energy conversion through a precisely designed reheat steam pipeline. During this process, the reheat regulating valve plays a crucial role, responsible for precisely controlling the steam flow to ensure stable turbine operation. However, as the opening of the reheat regulating valve gradually decreases, a significant phenomenon emerges: a sudden increase in pressure in a localized area upstream of the valve, far exceeding the pressure level of the mainstream flow in the pipeline. This abnormal increase in localized pressure not only seriously threatens the safety performance of the reheat steam valve but also significantly shortens its service life. More seriously, the increased pressure upstream of the valve can also significantly interfere with the mainstream steam flow, and in extreme cases, may even trigger backflow within the pipeline, posing a potential risk to the overall operation of the nuclear power plant.

[0005] Therefore, a pressure-reducing valve circuit structure at the pipeline valve is needed to solve the above problems. Summary of the Invention

[0006] This invention provides a pressure-reducing valve circuit structure at a pipeline valve to address a significant phenomenon that arises when the opening of the reheat regulating valve gradually decreases: a sudden increase in pressure in a localized area upstream of the valve, far exceeding the pressure level of the mainstream flow in the pipeline. This abnormal increase in localized pressure not only seriously threatens the safety performance of the reheat steam valve but also significantly shortens its service life. More seriously, the increased pressure upstream of the valve can also significantly interfere with the mainstream steam flow, and in extreme cases, may even trigger backflow within the pipeline, posing a potential risk to the overall operation of the nuclear power plant.

[0007] The present invention provides a pressure-reducing valve circuit structure at a pipeline valve, which adopts the following technical solution, including: Two steam regulating valves are installed at intervals within the main reheat steam pipeline; The pressure-reducing loop pipeline has one end connected to the side wall of the reheat steam main pipeline between two steam regulating valves via a pressure-reducing valve assembly, and is connected to the reheat steam main pipeline. The other end is connected to the reheat steam main pipeline from the upstream side wall of the reheat steam main pipeline. The guide impeller assembly is installed inside the pressure reduction circuit pipeline; And a drive assembly for driving the flow guide impeller assembly to rotate and guide the medium in the pressure reduction circuit pipeline; Specifically, when the upstream and downstream pressure difference at the connection port between the pressure reducing valve assembly and the pressure reducing circuit pipeline drives the valve core of the pressure reducing valve assembly to open, the valve core triggers the switching component of the drive assembly to open, and the drive assembly works to drive the guide impeller assembly to work; when there is no pressure difference between the upstream and downstream at the connection port between the pressure reducing valve assembly and the pressure reducing circuit pipeline, the valve core closes, the switching component closes, and the drive assembly stops working.

[0008] Preferably, the pressure reducing valve assembly includes: The pressure-reducing pipeline connects the end of the pressure-reducing loop pipeline to the reheat steam main pipeline. It contains a channel with a gradually decreasing diameter, which gradually decreases in diameter from the reheat steam main pipeline to the end of the pressure-reducing loop pipeline. The support plate is located inside the port of the pressure-reducing circuit pipeline. A valve core is connected to the end of the support plate facing the pressure-reducing pipeline via an elastic component. The valve core is used to block the small port of the channel. An airflow channel for steam to pass through is provided on the support plate. And the valve stem, which is mounted on the support plate, with one end vertically connected to the valve core and the other end used to trigger the switch assembly to open or close.

[0009] Preferably, the switching assembly includes: A switch trigger rod has a hinged ball in its middle. The hinged ball is rotatably mounted on a pressure-reducing circuit pipe connected to the end of the pressure-reducing pipe. A sealing ball sleeve is provided between the hinged ball and the inner wall of the ball hole on the pressure-reducing circuit pipe. One end of the switch trigger rod is located inside the pressure-reducing circuit pipe, and the other end of the switch trigger rod is located outside the pressure-reducing circuit pipe. A switch fixing rod is horizontally fixed to the outer wall of the step-down circuit pipeline, and a first reset spring is provided between the switch fixing rod and the switch trigger rod outside the step-down circuit pipeline; A conductor is disposed between the ends of the switch fixing rod and the switch trigger rod away from the step-down circuit pipe. One conductor is connected to the power supply via a wire, and the other conductor is connected to the power input terminal of the drive component via a wire. The power supply is also connected to the power input terminal of the drive component. Under differential pressure, the valve core moves upward, driving the valve stem to move upward and push the switch trigger rod to rotate around the hinge ball, causing the two conductors on the switch fixing rod and the switch trigger rod to contact, and the drive assembly starts to work. When there is no differential pressure, the valve core closes, and under the action of the first return spring, the switch fixing rod and the switch trigger rod reset, the two conductors separate, and the drive assembly stops working.

[0010] Preferably, the elastic component includes a plurality of second return springs, which are evenly distributed around the center of the valve core. A plurality of first spring seats are evenly distributed around the center of the valve core, and a plurality of second spring seats corresponding to the first spring seats are provided on the support plate. Each second return spring is connected between the corresponding first spring seat and the second spring seat.

[0011] Preferably, the guide impeller assembly includes: a guide fan concentrically disposed within the pressure reduction circuit pipe, the center of which is connected to the output end of the drive assembly, wherein the drive assembly includes: a drive motor, the output shaft of which is horizontally inserted into the pressure reduction circuit pipe and then concentrically fixed with the guide fan.

[0012] Preferably, the steam regulating valve facing upstream of the reheat steam main pipeline is the main steam regulating valve, and the steam regulating valve facing downstream of the reheat steam main pipeline is the auxiliary steam regulating valve. The main steam regulating valve is used to control the total opening of the reheat steam main pipeline, and the auxiliary steam regulating valve is used to adjust the opening of the reheat steam main pipeline downstream of the main steam regulating valve when the pressure is reduced, so that a pressure difference is generated between the upstream and downstream of the pressure reducing valve assembly and the pressure reducing loop pipeline connection port. The main steam regulating valve is located in the reheat steam main pipeline between the two side wall connection ports of the reheat steam main pipeline.

[0013] Preferably, the inner wall of the channel is an inwardly convex arc surface.

[0014] Preferably, a liquid accumulation zone is formed between the outer wall of the channel and the inner wall of the pressure-reducing pipeline, and a drain hole for discharging liquid from the liquid accumulation zone is provided on the pressure-reducing pipeline.

[0015] Preferably, the ports of the pressure-reducing pipeline and the pressure-reducing loop pipeline, the ports of the pressure-reducing pipeline and the ports located on the side wall of the reheat steam main pipeline, and the ports of the pressure-reducing loop pipeline and the ports located on the side wall of the reheat steam main pipeline are all connected by connecting flanges.

[0016] Preferably, the middle part of the support plate is an airflow channel, and a connecting block is coaxially arranged in the airflow channel. The guide hole is opened on the connecting block, and the area of ​​the connecting block is smaller than that of the airflow channel.

[0017] The beneficial effects of this invention are: This invention optimizes fluid dynamics by installing a pressure-reducing circuit pipeline on the main steam pipeline and connecting it to the main steam pipeline via a pressure-reducing valve assembly. The gradually decreasing diameter channel within the pressure-reducing pipeline of the pressure-reducing valve assembly is utilized. Two steam regulating valves are installed within the main steam pipeline. The downstream steam regulating valve's throttling effect causes a corresponding increase in local pressure upstream of the downstream valve. This creates a significant pressure difference between the local pressure at the location of the downstream steam regulating valve and the main steam pressure downstream of it. This pressure difference forces the valve core to open, allowing steam to enter the pressure-reducing circuit through the airflow channel of the pressure-reducing valve assembly's support plate. Simultaneously, when the valve core opens, it triggers the switching component of the drive assembly to open, causing the drive assembly to rotate. As the guide impeller assembly rotates, the steam flow direction at this location shifts from the rear to the front of the guide impeller assembly, thus optimizing the steam flow in the pressure-reducing valve circuit. Furthermore, the low-pressure zone formed at the rear of the guide impeller assembly promotes rapid fluid flow from the inlet to the outlet of the pressure-reducing valve assembly, effectively reducing eddy currents in the flow field and improving the pressure-reducing efficiency of the valve assembly. Ultimately, this ensures stable operation of the pressure-reducing valve circuit and optimized steam flow, thereby improving the overall operating efficiency and safety of the steam system.

[0018] Secondly, by setting a limiting guide rod on the valve core, the present invention guides and positions the valve core, thereby ensuring that the valve core of the pressure reducing valve assembly will not undergo lateral displacement during the opening and closing process, and can always maintain a safe distance from the inner wall of the pressure reducing pipeline, avoiding any potential friction or collision, thereby ensuring the stability and reliability of the system. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of a pressure-reducing valve circuit at a pipeline valve according to the present invention; Figure 2 for Figure 1 A schematic diagram of the switch assembly in the diagram; Figure 3 for Figure 1 A schematic diagram of the valve core structure; Figure 4 for Figure 3 A schematic diagram of the support plate in the diagram.

[0021] In the diagram: 1. Channel; 2. Valve core; 3. Second return spring; 4. Valve stem; 5. Support plate; 6. Switch fixing rod; 7. First conductor; 8. Second conductor; 9. Second return spring; 10. Switch trigger rod; 11. Hinge ball; 12. Drive motor; 13. Motor insulation layer; 14. Power supply insulation layer; 15. Power supply; 16. Output shaft; 17. Guide fan; 18. Pressure reducing valve circuit pipeline; 19. Reheat steam main pipeline; 20. Main steam regulating valve; 21. Auxiliary steam regulating valve; 101. Small port; 201. Drain hole; 31. First spring seat; 51. Second spring seat; 52. Airflow channel; 53. Guide hole. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] An embodiment of the pressure-reducing valve circuit structure at a pipeline valve according to the present invention is as follows: Figure 1As shown, the system includes: a pressure-reducing loop pipe 18, a guide impeller assembly, a drive assembly, and two steam regulating valves. The two steam regulating valves are spaced apart within the reheat steam main pipe 19. One end of the pressure-reducing loop pipe 18 is connected to the side wall of the reheat steam main pipe 19 between the two steam regulating valves via the pressure-reducing valve assembly, and is connected to the reheat steam main pipe 19. The other end of the pressure-reducing loop pipe 18 is connected to the upstream side wall of the reheat steam main pipe 19. The guide impeller assembly is disposed within the pressure-reducing loop pipe 18. The drive assembly is used to drive the guide impeller assembly to rotate and guide the medium in the pressure-reducing loop pipe 18. When the upstream and downstream pressure difference at the connection port between the pressure-reducing valve assembly and the pressure-reducing loop pipe 18 drives the valve core 2 of the pressure-reducing valve assembly to open, the valve core 2 triggers the switch assembly of the drive assembly to open, and the drive assembly drives the guide impeller assembly to work. When there is no upstream and downstream pressure difference at the connection port between the pressure-reducing valve assembly and the pressure-reducing loop pipe 18, the valve core 2 closes, the switch assembly closes, and the drive assembly stops working.

[0024] For example, in one specific embodiment, the pressure reducing valve assembly includes: a pressure reducing pipeline, a support plate 5, and a valve stem 4. The pressure reducing pipeline is connected between the end of the pressure reducing loop pipe 18 and the reheat steam main pipe 19. A channel 1 with a gradually decreasing diameter is provided in the pressure reducing pipeline. The diameter of the channel 1 gradually decreases from the reheat steam main pipe 19 to the end of the pressure reducing loop pipe 18. The arrangement of the channel 1 with a gradually decreasing diameter optimizes the hydrodynamic performance. The support plate 5 is disposed in the port of the pressure reducing loop pipe 18. A valve core 2 is connected to the end of the support plate 5 facing the pressure reducing pipeline through an elastic component 3. The valve core 2 is used to block the small port 101 of the channel 1. An airflow channel 52 for steam to pass through is provided on the support plate 5. The valve stem 4 passes through the support plate 5. One end of the valve stem 4 is perpendicularly connected to the valve core 2. The other end of the valve stem 4 is used to trigger the switch assembly to open or close. The first purpose of setting the valve stem 4 is to further and more accurately position the valve core 4 of the pressure reducing valve assembly, that is, to guide it so that the valve core 4 can be accurately blocked on the small port 101.

[0025] For example, in one specific embodiment, in order to further accurately position the valve core 4 of the pressure reducing valve assembly, the valve core 3 is provided with a positioning protrusion that mates with the small port 101, wherein, as shown... Figure 4As shown, the middle part of the support plate 4 is the airflow channel 52. A connecting block is coaxially arranged in the airflow channel 52. The guide hole 53 is opened on the connecting block, and the area of ​​the connecting block is smaller than that of the airflow channel 52. It should be noted that the cooperation structure between the valve stem 4 and the guide hole 53 effectively prevents the valve core 3 from lateral displacement that may occur during operation. That is, it ensures that the valve core 3 can always maintain a safe distance from the inner wall of the pressure reducing pipeline 2 during the dynamic process of opening and closing, avoiding any potential friction or collision, thereby completely eliminating safety hazards. This ensures that the valve core 4 can accurately cover the small port 101, guaranteeing the stability and reliability of the system.

[0026] For example, in one specific embodiment, such as Figure 1 and 2 As shown, the switch assembly includes: a switch trigger rod 10, a switch fixing rod 6, a first conductor 7, and a second conductor 8. A hinged ball 11 is disposed in the middle of the switch trigger rod 10. The hinged ball 11 is rotatably mounted on a step-down circuit pipe 18 connected to the end of the step-down pipe. A sealing ball sleeve is provided between the hinged ball 11 and the inner wall of the ball hole on the step-down circuit pipe 18. One end of the switch trigger rod 10 is located inside the step-down circuit pipe 18, and the other end is located outside the step-down circuit pipe 18. The switch fixing rod 6 is horizontally fixed to the outer wall of the step-down circuit pipe 18, and a first return spring 9 is provided between the switch fixing rod 6 and the switch trigger rod 10 outside the step-down circuit pipe 18. The first conductor 7 is disposed on the switch fixing rod 6, and the second conductor 8 is disposed on the switch trigger rod 10. The first conductor 7 is disposed at the end of the switch fixing rod 6 away from the step-down circuit pipe 18, and the second conductor 8 is disposed at the end of the switch trigger rod 10 away from the step-down circuit pipe 18. The first conductor 7 and the first conductor 8 are arranged opposite each other. After the switch trigger rod 10 rotates and comes into contact with the switch trigger rod 10, the first conductor 7 and the first conductor 8 are energized. The first conductor 7 is connected to the power supply 15 through a wire, and the first conductor 8 is connected to the power input terminal of the drive assembly through a wire. The power supply 15 is also connected to the power input terminal of the drive assembly. It should be noted that in this embodiment, when a pressure difference is generated upstream and downstream at the connection port between the pressure reducing valve assembly and the pressure reducing circuit pipeline 18, the pressure difference drives the medium to move the valve core 2 upward. The valve core 2 drives the valve stem 4 upward to push the switch trigger rod 10 to rotate around the hinge ball 11, so that the switch fixing rod 6 of the switch assembly and the two conductors on the switch trigger rod 10 come into contact, that is, the switch assembly is turned on and the drive assembly starts to work. When there is no pressure difference, the valve core 2 is closed. Under the action of the first return spring 9, the switch fixing rod 6 and the switch trigger rod 10 are reset, the two conductors separate, and the switch assembly is turned off, and the drive assembly stops working.

[0027] For example, in one specific embodiment, such as Figure 1 , Figure 3 and Figure 4As shown, the elastic component 3 includes multiple second return springs, which are evenly distributed around the center of the valve core 2. Multiple first spring seats 31 are evenly distributed around the center of the valve core 2. Multiple second spring seats 51 corresponding to the first spring seats 31 are provided on the support plate 5. Each second return spring is connected between the corresponding first spring seat 31 and the second spring seat 51.

[0028] For example, in one specific embodiment, such as Figure 1 As shown, the guide impeller assembly includes: a guide fan 17 concentrically disposed within the step-down circuit pipe 18, with its center connected to the output end of the drive assembly. The drive assembly includes: a drive motor, the output shaft 16 of which is horizontally inserted into the step-down circuit pipe 18 and concentrically fixed with the guide fan 17. A motor insulation layer 13 is provided between the drive motor and the outer wall of the step-down circuit pipe 18, and a power supply insulation layer 14 is provided between the power supply 15 and the outer wall of the step-down circuit pipe 18 to prevent the heat generated by the drive motor and the power supply 15 from affecting the medium inside the step-down circuit pipe 18.

[0029] For example, in one specific embodiment, such as Figure 1 As shown, the steam regulating valve upstream of the reheat steam main pipeline 19 is the main steam regulating valve 20, and the steam regulating valve downstream of the reheat steam main pipeline 19 is the auxiliary steam regulating valve 21. The main steam regulating valve 20 is used to control the total opening of the reheat steam main pipeline 19, and the auxiliary steam regulating valve 21 is used to adjust the opening of the reheat steam main pipeline 19 downstream of the main steam regulating valve 20 when pressure is reduced, so that a pressure difference is generated upstream and downstream at the connection port of the pressure reducing valve assembly and the pressure reducing loop pipeline 18. The main steam regulating valve 20 is located in the reheat steam main pipeline 19 between the two side wall connection ports. That is, when the fluid passes through the auxiliary steam regulating valve 21 of the reheat steam main pipeline 19, the local pressure upstream of the auxiliary steam regulating valve 21 will rise accordingly due to the throttling effect of the auxiliary steam regulating valve 21. At this time, a significant pressure difference is formed between the local pressure at the location of the auxiliary steam regulating valve 21 and the main steam pressure downstream of the auxiliary steam regulating valve 21. This pressure difference is the key power source for driving the pressure reducing valve to open and close.

[0030] like Figure 1As shown, the inner wall of channel 1 is an inwardly convex arc surface. A liquid accumulation zone is formed between the outer wall of channel 1 and the inner wall of pressure reducing pipeline 2. In order to avoid the accumulation of liquid in these liquid accumulation zones during the operation of the pressure reducing valve circuit device, which may cause safety hazards, this embodiment provides a drain hole 201 for draining liquid from the liquid accumulation zone on the pressure reducing pipeline 2. When the pressure reducing valve circuit device stops operating, the liquid can be drained through these drain holes 201 to ensure that the inside of the pressure reducing pipeline 2 remains dry and clean. This design not only effectively maintains the safe and stable operation of the pipeline system, but also greatly simplifies the subsequent maintenance work and improves the reliability and service life of the overall system.

[0031] For example, in one specific embodiment, the ports of the pressure-reducing pipeline 2 and the pressure-reducing loop pipeline 18, the ports of the pressure-reducing pipeline 2 and the ports provided on the side wall of the reheat steam main pipeline 19, and the ports of the pressure-reducing loop pipeline 18 and the ports provided on the side wall of the reheat steam main pipeline 19 are all connected by connecting flanges.

[0032] Working principle In use, the throttling effect of the auxiliary steam regulating valve 21 causes a corresponding increase in the local pressure upstream of the auxiliary steam regulating valve 21. At this time, a significant pressure difference is formed between the local pressure at the location of the auxiliary steam regulating valve 21 and the main steam pressure downstream of the auxiliary steam regulating valve 21. This pressure difference force drives the valve core 3 to open automatically, i.e. Figure 1As shown, the upward movement of the valve core 3 drives the valve stem 4 to move upward. When the valve stem 4 is raised to a certain distance, it pushes the switch trigger rod 10 to rotate around the hinge ball 11, so that the end of the switch trigger rod 10 located outside the pressure reducing valve circuit pipe 18 moves closer to the switch fixing rod 6 until the first conductor 7 on the switch fixing rod 6 and the second conductor 8 on the switch trigger rod 10 come into contact. At this time, the switch assembly is turned on, the drive motor 12 starts to work, and the output shaft 16 of the drive motor 12 drives the guide fan 17 in the pressure reducing valve circuit pipe 18 to rotate. When the guide fan 17 rotates, the steam flow direction in this part flows from the rear of the guide fan 17 to the front of the guide fan 17, which optimizes the steam flow in the pressure reducing valve circuit pipe 18 and improves the pressure reducing efficiency of the pressure reducing valve assembly. The structure of the pressure reducing valve assembly causes vortices in the flow field at this location. The presence of the guide fan 17 inside the pipe plays a role in planning the flow path of the pressure reducing valve loop pipe 18. When the guide fan 17 is working, a low-pressure zone is formed behind the guide fan. The presence of the low-pressure zone promotes the fluid at the inlet of the pressure reducing valve assembly to flow better through the pressure reducing valve assembly and out of the pressure reducing valve assembly outlet. The rapid passage of steam fluid through the pressure reducing valve assembly effectively reduces the occurrence of vortices in the flow field at this location. Ultimately, steam enters the pressure reducing loop pipe from the airflow channel of the support plate of the pressure reducing valve assembly. After being driven by the guide fan 17, the steam flows back from the pressure reducing loop pipe to the pressure reducing loop pipe, thereby reducing the pressure of the reheat steam main pipe 19 and improving the operating efficiency and safety of the entire steam system.

[0033] When the pressure reducing valve assembly stops working, the valve core 2 begins to move downward under the action of the second reset spring, and the valve stem 4 moves downward accordingly. The valve stem 4 disengages from the switch trigger rod 10. Under the action of the second reset spring of the motor switch, the switch assembly disengages from the switch trigger rod 10 and the switch fixing rod 6. At this time, the motor switch assembly is closed, the motor is powered off and stops working, and the guide fan 13 stops rotating.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressure-reducing valve circuit structure at a pipeline valve, characterized in that, include: Two steam regulating valves are installed at intervals within the main reheat steam pipeline; The pressure-reducing loop pipeline has one end connected to the side wall of the reheat steam main pipeline between two steam regulating valves via a pressure-reducing valve assembly, and is connected to the reheat steam main pipeline. The other end is connected to the reheat steam main pipeline from the upstream side wall of the reheat steam main pipeline. The guide impeller assembly is installed inside the pressure reduction circuit pipeline; And a drive assembly for driving the flow guide impeller assembly to rotate and guide the medium in the pressure reduction circuit pipeline; Specifically, when the upstream and downstream pressure difference at the connection port between the pressure reducing valve assembly and the pressure reducing circuit pipeline drives the valve core of the pressure reducing valve assembly to open, the valve core triggers the switching component of the drive assembly to open, and the drive assembly works to drive the guide impeller assembly to work; when there is no pressure difference between the upstream and downstream at the connection port between the pressure reducing valve assembly and the pressure reducing circuit pipeline, the valve core closes, the switching component closes, and the drive assembly stops working.

2. The pressure-reducing valve circuit structure at a pipeline valve according to claim 1, characterized in that, The pressure reducing valve assembly includes: The pressure-reducing pipeline connects the end of the pressure-reducing loop pipeline to the reheat steam main pipeline. It contains a channel with a gradually decreasing diameter, which gradually decreases in diameter from the reheat steam main pipeline to the end of the pressure-reducing loop pipeline. The support plate is located inside the port of the pressure-reducing circuit pipeline. A valve core is connected to the end of the support plate facing the pressure-reducing pipeline via an elastic component. The valve core is used to block the small port of the channel. An airflow channel for steam to pass through is provided on the support plate. And the valve stem, which is mounted on the support plate, with one end vertically connected to the valve core and the other end used to trigger the switch assembly to open or close.

3. The pressure-reducing valve circuit structure at a pipeline valve according to claim 2, characterized in that, The switch assembly includes: A switch trigger rod has a hinged ball in its middle. The hinged ball is rotatably mounted on a pressure-reducing circuit pipe connected to the end of the pressure-reducing pipe. A sealing ball sleeve is provided between the hinged ball and the inner wall of the ball hole on the pressure-reducing circuit pipe. One end of the switch trigger rod is located inside the pressure-reducing circuit pipe, and the other end of the switch trigger rod is located outside the pressure-reducing circuit pipe. A switch fixing rod is horizontally fixed to the outer wall of the step-down circuit pipeline, and a first reset spring is provided between the switch fixing rod and the switch trigger rod outside the step-down circuit pipeline; A conductor is disposed between the ends of the switch fixing rod and the switch trigger rod away from the step-down circuit pipe. One conductor is connected to the power supply via a wire, and the other conductor is connected to the power input terminal of the drive component via a wire. The power supply is also connected to the power input terminal of the drive component. Under differential pressure, the valve core moves upward, driving the valve stem to move upward and push the switch trigger rod to rotate around the hinge ball, causing the two conductors on the switch fixing rod and the switch trigger rod to contact, and the drive assembly starts to work. When there is no differential pressure, the valve core closes, and under the action of the first return spring, the switch fixing rod and the switch trigger rod reset, the two conductors separate, and the drive assembly stops working.

4. The pressure-reducing valve circuit structure at a pipeline valve according to claim 2, characterized in that, The elastic component includes multiple second return springs, which are evenly distributed around the center of the valve core. Multiple first spring seats are evenly distributed around the center of the valve core. Multiple second spring seats corresponding to the first spring seats are provided on the support plate. Each second return spring is connected between the corresponding first spring seat and the second spring seat.

5. The pressure-reducing valve circuit structure at a pipeline valve according to claim 1, characterized in that, The guide impeller assembly includes: a guide fan concentrically arranged inside the step-down circuit pipe, the center of which is connected to the output end of the drive assembly. The drive assembly includes: a drive motor, the output shaft of which is horizontally inserted into the step-down circuit pipe and then concentrically fixed with the guide fan.

6. The pressure-reducing valve circuit structure at a pipeline valve according to claim 1, characterized in that, The steam regulating valve facing upstream of the reheat steam main pipeline is the main steam regulating valve, and the steam regulating valve facing downstream of the reheat steam main pipeline is the auxiliary steam regulating valve. The main steam regulating valve is used to control the total opening of the reheat steam main pipeline, and the auxiliary steam regulating valve is used to adjust the opening of the reheat steam main pipeline downstream of the main steam regulating valve when the pressure is reduced, so that a pressure difference is generated between the upstream and downstream of the pressure reducing valve assembly and the pressure reducing loop pipeline connection port. The main steam regulating valve is located in the reheat steam main pipeline between the two side wall connection ports of the reheat steam main pipeline.

7. The pressure-reducing valve circuit structure at a pipeline valve according to claim 1, characterized in that, The inner wall of the channel is an inwardly convex arc surface.

8. The pressure-reducing valve circuit structure at a pipeline valve according to claim 1, characterized in that, A liquid accumulation zone is formed between the outer wall of the channel and the inner wall of the pressure-reducing pipeline, and a drain hole is provided on the pressure-reducing pipeline for the liquid to be discharged from the liquid accumulation zone.

9. The pressure-reducing valve circuit structure at a pipeline valve according to claim 1, characterized in that, The ports of the pressure-reducing pipeline and the pressure-reducing loop pipeline, the ports of the pressure-reducing pipeline and the ports located on the side wall of the reheat steam main pipeline, and the ports of the pressure-reducing loop pipeline and the ports located on the side wall of the reheat steam main pipeline are all connected by connecting flanges.

10. The pressure-reducing valve circuit structure at a pipeline valve according to claim 1, characterized in that, The middle part of the support plate is an airflow channel, and a connecting block is coaxially arranged in the airflow channel. The guide hole is opened on the connecting block, and the area of ​​the connecting block is smaller than that of the airflow channel.

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