Silencing device for atmospheric emission system of nuclear power plant

Abstract

A silencer for an atmospheric emission system of a nuclear power plant belongs to the technical field of steam silencing, and comprises a mounting base, a shell connected and arranged above the mounting base, a resistance structure connected and fixed in the shell and arranged above the mounting base, and a resistive structure arranged at the top of the resistance structure; the resistant structure is communicated with an atmospheric discharge valve of an external main steam system; a gap is formed between the resistive structure and the reactive structure; after airflow noise in the main steam system is suppressed by the resistance structure and the resistive structure in sequence, water vapor is discharged from the top of the shell. The resistance structure and the resistive structure are arranged, so that composite noise can be effectively restrained, simultaneous connection of a plurality of loop drain valves can be achieved on the same mounting platform, the function that a plurality of atmosphere drain valves discharge steam at the same time is achieved, and interference can be effectively prevented from being formed when a plurality of loops discharge steam at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of steam silencing, and relates to a steam silencing device for the atmospheric discharge of nuclear power plants. Specifically, it relates to a high-performance silencing device suitable for the atmospheric discharge valve of the main steam system of nuclear power plants. Background Art

[0002] The power of the nuclear power plant reactor cannot be changed as quickly as the load of the steam turbine generator. When the load of the steam turbine drops significantly, the steam turbine bypass system directly discharges the main steam into the condenser, thereby providing an "artificial" load for the reactor and reducing the transient change range of temperature and pressure in the nuclear steam supply system. When the steam turbine bypass system cannot be used, during the startup and shutdown of the nuclear power plant, the power increase and decrease, and after the relevant predicted operating events and design basis accidents, the atmospheric discharge system discharges the steam in the secondary circuit to the atmosphere to reduce the temperature and pressure of the secondary circuit, preventing overpressure and excessive temperature rise of the reactor coolant system.

[0003] As the main equipment for reducing noise in the current atmospheric discharge system, the atmospheric discharge valve silencer mainly plays the role of reducing the discharge noise. Its working principle is that the silencer is connected to the high-pressure steam pipeline. Through multiple layers of orifice plates and resistive silencing elements, using the resistive or reactive silencing principle, the flow rate and pressure are gradually reduced, and the impact noise generated by gas expansion is reduced. However, with the development of nuclear power technology, the improvement of reactor types and the research and development of new reactor types have continuously increased the requirements for equipment. Each traditional silencer can only be targeted at one loop. Therefore, multiple silencers need to be used to form connections with each loop respectively. Since each silencer requires a mounting platform, multiple silencers require multiple mounting platforms, resulting in a large space occupancy rate and high manufacturing costs. In addition, when the maximum discharge flow rate appears in the loop, for safety reasons, each single silencer needs to meet the safety requirements of the maximum flow rate discharge, and the cylinder body design is relatively large.

[0004] Summary of the Invention Aiming at the deficiencies of the prior art, the invention provides a silencing device for the atmospheric discharge system of nuclear power plants. This device has a small space occupancy rate. The discharge valves of multiple loops of the atmospheric discharge system can be simultaneously connected to this silencing device. Different chambers are formed between the reactive sections by partitions so as not to generate backpressure interference with each other, meeting the system function requirements, reducing the noise during the exhaust process of the atmospheric discharge valve, having a good noise reduction effect, especially having a significant effect on suppressing composite noise, and reducing the noise pollution of nuclear power plants.

[0005] The silencing device for the atmospheric discharge system of nuclear power plants provided by this application adopts the following technical solutions: A silencing device for the atmospheric discharge system of nuclear power plants includes a mounting base and a housing connected and arranged above the mounting base. It is characterized in that the device further includes: The resistance structure is connected and fixed inside the housing and placed above the mounting base. The resistance structure is communicated with the atmospheric discharge valve of the external main steam system. The resistance structure is connected and fixed inside the housing and placed on top of the resistance structure. There is a gap between the resistance structure and the resistance structure.

[0006] By adopting the above technical solution, after the airflow noise in the main steam system is successively suppressed by the resistance structure and the resistance structure, the water vapor is discharged from the top of the housing, and the composite noise suppression effect is remarkable, reducing the noise pollution of the nuclear power plant.

[0007] Furthermore, the resistance structure is composed of a bottom plate, a resistance cylinder, and a connecting pipe. The bottom plate is connected and fixed to the inner wall of the housing. The resistance cylinder is fixedly installed on the bottom plate, and there is a gap between the bottom plate and the mounting base. The connecting pipe is placed in the gap. One end of the connecting pipe is communicated with the bottom of the resistance cylinder, and the other end passes through the housing and is connected to the atmospheric discharge pipe of the main steam system.

[0008] By adopting the above technical solution, when the main steam system discharges high-temperature steam, due to the high airflow speed, the impact and pressure fluctuation of the two-phase fluid inside the steam generator are relatively large, which intensifies the low-frequency vibration of the pipeline and the shell. The resistance structure can effectively suppress the low-frequency noise, play a role in reducing pressure and shifting frequency, and enhance the sound absorption effect of the resistance section.

[0009] Furthermore, the number of the resistance cylinders is 3, and a flow channel partition plate is provided between adjacent two resistance cylinders to form independent resistance chambers.

[0010] By adopting the above technical solution, a flow channel partition plate is arranged between the resistance cylinders, effectively preventing interference when multiple loops discharge simultaneously.

[0011] Furthermore, a pedestrian passage is connected to the top of the flow channel partition plate, and a ladder connected to each resistance chamber is provided on one side of the pedestrian passage.

[0012] By adopting the above technical solution, the setting of the pedestrian passage is conducive to the maintenance personnel to inspect or maintain each resistance chamber.

[0013] Furthermore, the resistance cylinder is composed of multiple levels of coaxial diffusion cylinders from the inside to the outside. The central diffusion cylinder is communicated with the exhaust valve of the main steam system through a connecting pipe, and a head is connected to the top of the whole resistance cylinder.

[0014] By adopting the above technical solution, using the multi-level diffusion cylinder structure, the high-speed airflow is decelerated step by step, reducing the impact and noise when the gas is ejected. Further, when the three loops do not discharge simultaneously, the discharging loop can utilize the resistive section flow-through channel shared by the three loops to effectively reduce the flow rate, thereby better reducing noise.

[0015] Further, the resistive structure is composed of sleeves arranged coaxially in multiple stages and fixed steel connections. There is a gap between each stage of sleeves, and each stage of sleeve is fixed by fixed steel and connected and fixed to the shell.

[0016] By adopting the above technical solution, the sleeves arranged in multiple stages can convert the acoustic wave energy into heat energy. When the acoustic wave penetrates the material, the air molecules in the gap rub against the sleeve wall to generate viscous resistance, which can effectively reduce the high-frequency noise of the gas jet in the steam generator in the secondary circuit. At the same time, part of the condensed water can also be formed when the steam contacts the sleeve.

[0017] Further, a first maintenance port and a second maintenance port communicating with the inside of the shell are provided on the shell. The first maintenance port is flush with the pedestrian passage, and the second maintenance port is communicated and arranged at the gap formed between the resistive structure and the mounting base.

[0018] By adopting the above technical solution, the resistive cylinder is maintained by using the first maintenance port, and the connecting pipe is maintained by using the second maintenance port.

[0019] Further, the mounting base is composed of a mounting plate, a seat cylinder, a water collecting plate and bolt seats connected. The seat cylinder is connected and fixed to the mounting plate, the water collecting plate is arranged on the seat cylinder, and the bolt seats are distributed along the circumferential direction of the mounting plate and are connected and fixed to the seat cylinder.

[0020] By adopting the above technical solution, the setting of the water collecting plate is beneficial to the condensation of water vapor into liquid water at the end of the exhaust pipe. The drain hole can discharge the accumulated water in time to avoid the risk of internal corrosion or freezing and cracking of the muffler due to long-term accumulation; the bolt seats distributed in the circumferential direction are beneficial to the connection and fixation of the entire muffling device to the buried bolts on the installation platform.

[0021] Further, the water collecting plate is in a conical structure, a water collecting hole is provided at the center, and drain holes are provided on the outer wall of the seat cylinder, and the drain holes are communicated with the water collecting hole.

[0022] By adopting the above technical solution, the conical water collecting plate is more beneficial to the aggregation of condensed water, and the setting of the water collecting hole is beneficial to the real-time discharge of the condensed accumulated water.

[0023] In summary, the present invention includes at least one of the following beneficial technical effects: (1) In the present invention, by setting the resistive structure, the impact and pressure of the two-phase fluid inside the steam generator can be reduced, and the low-frequency noise can be effectively suppressed.

[0024] (2) In the present invention, by providing a resistive structure, when sound waves penetrate the material, the air molecules in the pores will generate viscous resistance due to friction with the resistive body, which can effectively reduce the high-frequency noise of gas jets in the steam generator, steam turbine generator set, and condenser in the secondary loop.

[0025] (3) In the present invention, by providing a flow channel partition plate between the reactive cylinders, it can effectively prevent interference when multiple loops discharge simultaneously.

[0026] (4) The device structure of the present invention is novel. Multiple loop discharge valves can be simultaneously connected on one installation platform. The device has a small space occupancy rate, meets the function of discharging steam by multiple atmosphere discharge valves simultaneously, reduces the construction quantity of the installation platforms for traditional single mufflers, and reduces the operation cost.

[0027] (5) A pedestrian passage and a ladder are provided in the device of the present invention, which is beneficial for maintenance personnel to conduct inspections on each reactive chamber, improving the later inspection and maintenance efficiency. Description of the Drawings

[0028] Figure 1 is a schematic diagram of the overall structure of the present invention from the first angle.

[0029] Figure 2 is a schematic diagram of the overall structure of the present invention from the second angle.

[0030] Figure 3 is a schematic diagram of the installation structure of the base and the housing in the present invention.

[0031] Figure 4 is a schematic diagram of the exploded structure of the overall structure of the present invention.

[0032] Figure 5 is a schematic diagram of the overall top view structure of the present invention.

[0033] Figure 6 is Figure 5 the schematic diagram of the A-A full-section structure in

[0034] Figure 7 is a schematic diagram of the resistive structure and the installation base in the present invention.

[0035] Figure 8 is a schematic diagram of the external structure of the reactive cylinder in the present invention.

[0036] Figure 9 is a schematic diagram of the full-section structure of the reactive cylinder in the present invention.

[0037] In the figure: mounting base 1, mounting plate 1-1, seat cylinder 1-2, water collecting plate 1-3, water collecting hole 1-4, drain hole 1-5, bolt seat 1-6, connecting pipe 2, housing 3, drain flange 3-1, resistive structure 4, sleeve 4-1, fixed section steel 4-2, first inspection opening 5, second inspection opening 6, reactive structure 7, bottom plate 8, reactive cylinder 9, central diffuser 9-1, primary diffuser 9-2, secondary diffuser 9-3, tertiary diffuser 9-4, head 9-5, diffuser hole 9-6, flow path partition plate 10, pedestrian passage 11, ladder 12. Detailed implementation manners

[0038] The present invention will be further clarified below in conjunction with the accompanying drawings and specific implementation manners. It should be understood that these implementation manners are only used to illustrate the invention patent and not to limit the scope of the invention patent. After reading the invention patent, various equivalent modifications made by those skilled in the art fall within the scope defined by the appended claims of this application.

[0039] Embodiment 1 As Figures 1-4 shown, a silencing device for a nuclear power plant atmospheric emission system is composed of a mounting base 1, a housing 3 connected and arranged above the mounting base 1, a reactive structure 7 connected and fixed inside the housing 3 and placed above the mounting base 1, and a resistive structure 4 connected and fixed inside the housing 3 and placed on top of the reactive structure 7; the reactive structure 7 is communicated with the atmospheric emission valve of the external main steam system; there is a gap between the resistive structure 4 and the reactive structure 4; after the airflow noise in the main steam system passes through the reactive structure 7 and the resistive structure 4 for suppression in sequence, the saturated water vapor is discharged from the top of the housing 3.

[0040] In order to effectively suppress the impact and pressure fluctuation of the two-phase fluid inside the steam generator, and the low-frequency vibration of the pipeline and the outer shell when the main steam system discharges high-temperature steam, a reactive structure is adopted in this embodiment. Specifically, as Figure 4 , Figure 6 , Figure 7 shown, the reactive structure 7 is composed of a bottom plate 8, a reactive cylinder 9, and a connecting pipe 2; the bottom plate 8 is connected and fixed to the inner wall of the housing 3, the reactive cylinder 9 is fixedly installed on the bottom plate 8, and there is a gap between the bottom plate 8 and the mounting base 1. The connecting pipe 2 is placed in the gap. One end of the connecting pipe 2 is communicated with the bottom of the reactive cylinder 9, and the other end passes through the housing 3 and is connected to the atmospheric discharge pipe of the main steam system. A drain flange 3-1 is provided on the outer wall of the bottom of the reactive cylinder 9 to facilitate the discharge of the condensed water above the bottom plate 8.

[0041] In order to effectively reduce the high-frequency noise of the gas jet in the steam generator, the steam turbine generator set, and the condenser in the secondary loop, a resistive structure is adopted in this embodiment. Specifically, as Figure 4 , Figure 5As shown, the resistive structure 4 is composed of a multi-stage coaxially arranged sleeve 4-1 and a fixed steel bar 4-2. There is a gap between each stage of the sleeve 4-1. Each stage of the sleeve 4-1 is fixed by the fixed steel bar 4-2 and is fixedly connected to the housing 3. The acoustic energy is converted into heat energy. When the sound wave penetrates the material, the air molecules in the gap rub against the sleeve wall to generate viscous resistance, which can effectively reduce the high-frequency noise of the gas jet in the steam generator in the secondary loop. At the same time, when the steam contacts the sleeve, partial condensate can also be formed.

[0042] Through the combined action of the above-mentioned reactive structure and resistive structure, it can adapt to the noise elimination requirements of different frequencies and has a significant effect on suppressing composite noise.

[0043] Embodiment 2 In order to enable multiple loop discharge valves to be connected to the device for noise reduction simultaneously, in this embodiment, it is achieved by setting multiple reactive cylinders 9. Specifically, as Figure 4 、 Figure 7 shown, three reactive cylinders 9 are fixedly arranged on the bottom plate 8; in order to effectively prevent interference when multiple loops discharge simultaneously, in this embodiment, a flow channel partition plate 10 is arranged between the reactive cylinder 9 and the reactive cylinder 9. Specifically, as Figure 7 shown, the flow channel partition plate 10 is in a Y shape, so that each reactive cylinder 9 forms an independent reactive chamber.

[0044] In order to facilitate the inspection or maintenance personnel to inspect each reactive chamber, in this embodiment, a pedestrian passage 11 is arranged in the housing 3. Specifically, as Figure 7 shown, the pedestrian passage 11 is installed on the top of the flow channel partition plate 10 and is also in a Y shape; in order to facilitate the inspection or maintenance personnel to enter the reactive chamber to inspect the reactive cylinder, in this embodiment, a ladder 12 is arranged in each reactive cavity, so that the operator can use the ladder 12 to inspect the reactive cylinder 9.

[0045] In order to facilitate the maintenance of the reactive cylinder and the connecting pipe, in this embodiment, two inspection openings are arranged on the housing. Specifically, as Figure 6 shown, the first inspection opening is located between the reactive structure and the resistive structure and is flush with the pedestrian passage, so that after the operator enters from the first inspection opening, he can directly stand on the pedestrian passage for quick inspection; in order to facilitate the inspection of the connecting pipe 2, in this embodiment, it is achieved by setting a second inspection opening 6. Specifically, as Figure 6 shown, the second inspection opening 6 is arranged at the gap formed between the reactive structure 7 and the mounting base 1, so as to facilitate the inspection of the connection between this device and the atmospheric discharge valve pipeline in the main steam system.

[0046] Embodiment 3 In order to gradually decelerate the high-speed air flow discharged from the main steam system, in this embodiment, a multi-stage diffuser tube structure is adopted. Specifically, asFigure 8 , 9 As shown in 9 , the resistant cylinder body 9 is composed of multiple levels of coaxial diffusion cylinders from the inside out. The central diffusion cylinder 9-1 is connected to the exhaust valve of the main steam system through the connecting pipe 2. The first-stage diffusion cylinder 9-2, the second-stage diffusion cylinder 9-3, and the third-stage diffusion cylinder 9-4 are sequentially arranged outside the central diffusion cylinder. Diffusion holes 9-6 are evenly distributed on the cylinder wall of each stage of the diffusion cylinder. A head 9-5 is connected to the top of the entire resistant cylinder body 9, and the impact and noise during gas ejection are gradually reduced through multiple levels of diffusion cylinders.

[0047] In order to enable the condensed liquid water at the end of the exhaust pipe to be discharged in time and avoid the risk of internal corrosion or freezing and cracking of the muffler due to long-term accumulation, the structure of the installation base is improved in this embodiment. Specifically, as Figure 4 , Figure 6 shown in Figure 6 , the installation base 1 is connected and composed of an installation plate 1-1, a seat cylinder 1-2, a water collecting plate 1-3, and a bolt seat 1-6; the seat cylinder 1-2 is fixedly connected to the installation plate 1-1, the water collecting plate 1-2 is arranged on the seat cylinder 1-2, and the bolt seats 1-6 are distributed along the circumferential direction of the installation plate 1-1 and are fixedly connected to the seat cylinder 1-2. The water collecting plate 1-3 is in a conical structure, a water collecting hole 1-4 is provided at the center, a drain hole 1-5 is provided on the outer wall of the seat cylinder 1-2, and the drain hole 1-5 is communicated with the water collecting hole 1-4. The drain hole 1-5 can discharge the accumulated water in time, and the circumferentially distributed bolt seats 1-6 are beneficial to the connection and fixation of the entire muffler device to the buried bolts on the installation platform.

Claims

1. A silencing device for an atmospheric emission system of a nuclear power plant, comprising a mounting base (1) and a shell (3) connected to and arranged above the mounting base (1); characterized in that: The device also includes: A resistance structure (7) connected and fixed inside the shell (3) and placed above the mounting base (1), wherein the resistance structure (7) is connected to an atmospheric discharge valve of an external main steam system; The resistive structure (4) is connected and fixed inside the housing (3) and is placed on top of the reactive structure (7), with a gap being provided between the resistive structure (4); After the airflow noise in the main steam system is suppressed by the resistive structure (7) and the resistive structure (4) in sequence, the saturated water vapor is discharged from the top of the shell (3).

2. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 1, characterized in that: The resistance structure (7) is composed of a base plate (8), a resistance cylinder (9), and a connecting pipe (2); the base plate (8) is connected and fixed to the inner wall of the shell (3), the resistance cylinder (9) is fixedly installed on the base plate (8), and a gap is provided between the base plate (8) and the mounting base (1), and the connecting pipe (2) is placed in the gap, one end of the connecting pipe (2) is connected to the bottom of the resistance cylinder (9), and the other end passes through the shell (3) and is connected to the atmospheric discharge pipe of the main steam system.

3. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 2, characterized in that: The number of the resistant cylinders (9) is not less than 2, and a flow channel partition plate (10) is provided between two adjacent resistant cylinders (9) to form an independent resistant chamber.

4. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 3, characterized in that: A pedestrian passage (11) is connected to the top of the flow channel partition plate (10), and a ladder (12) connected to each resistance chamber is provided on one side of the pedestrian passage (11).

5. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 3, characterized in that: The resistance cylinder (9) is composed of multiple coaxial diffusion cylinders from the inside to the outside. The central diffusion cylinder (9-1) is connected to the exhaust valve of the main steam system through a connecting pipe (2). The top of the entire resistance cylinder (9) is connected with a head (9-5).

6. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 1, characterized in that: The resistive structure (4) is composed of multiple stages of coaxially arranged sleeves (4-1) and fixed steel sections (4-2) connected together, with gaps provided between each stage of sleeves (4-1), and each stage of sleeves (4-1) being fixed by the fixed steel sections (4-2) and connected and fixed to the housing (3).

7. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 1, characterized in that: The shell (3) is provided with a first inspection opening (5) and a second inspection opening (6) which are communicated with the interior of the shell (3); the first inspection opening (5) is arranged flush with the pedestrian passage (11); and the second inspection opening (6) is arranged in communication with the gap formed by the resistance structure (7) and the mounting base (1).

8. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 1, characterized in that: The mounting base (1) is composed of a mounting plate (1-1), a seat tube (1-2), a water collecting plate (1-3) and a bolt seat (1-6) connected together; the seat tube (1-2) is connected and fixed to the mounting plate (1-1), the water collecting plate (1-2) is arranged on the seat tube (1-2), and the bolt seats (1-6) are distributed along the circumferential direction of the mounting plate (1-1) and are connected and fixed to the seat tube (1-2).

9. A silencing device for an atmospheric emission system of a nuclear power plant according to claim 8, characterized in that: The water collecting plate (1-3) is in a conical structure, with a water collecting hole (1-4) provided at the center, and a drainage hole (1-5) is provided on the outer wall of the seat tube (1-2), and the drainage hole (1-5) is connected to the water collecting hole (1-4).

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