A one-way poppet valve simulator

Abstract

The utility model discloses a single -flow direction explosion valve simulation spare, including the tubular casing that is internally equipped with the reducing flow channel, the tubular casing is along the inside structure and has reducing flow channel, and reducing flow channel is sequentially provided with inlet section, taper section, minimum through -flow section, outlet section along its inside fluid's flow direction, minimum through -flow section is circumferentially provided with at least one diaphragm simulation spare, and diaphragm simulation spare is configured to be located on the arc convex block of minimum flow cross section, and the both sides of arc convex block are smoothly transitioned with minimum flow cross section and are integrated, along fluid flow direction, the cross -sectional area of arc convex block gradually reduces, through simulating the asymmetric flow field of explosion valve diaphragm after explosion, effectively overcome the flow distortion problem of existing center symmetry simulation spare, and the accuracy and reliability of flow resistance measurement of nuclear power plant safety injection pipeline debugging stage are improved.

Description

Technical Field

[0001] This utility model relates to a flow resistance simulation device, and more particularly to a unidirectional burst valve simulation device. Background Technology

[0002] The rupture valve flow resistance simulator is a test device used during the commissioning phase of a passive core cooling system in a nuclear power plant. Its function is to simulate the flow resistance characteristics of a real rupture valve in the pipeline without damaging it, and to accurately measure the flow parameters of the pipeline. Since the real rupture valve is a one-time opening device during nuclear power plant operation and cannot be reused during commissioning, the flow resistance simulator, with the same structural dimensions and equivalent flow resistance performance, replaces the real valve in the test pipeline, ensuring the integrity and sealing of the pipeline system, while simultaneously measuring the flow resistance of the safety injection line.

[0003] As shown in Chinese patent (CN113252298A), this type of simulation component is typically forged as a single piece, sequentially designed with an inlet section, a converging section, a flow passage section, a bell mouth, and an outlet. Its purpose is to meet the actual implementation requirements of the PXS system commissioning tests in CAP series nuclear power plants, ensuring accurate measurement and acquisition of test parameters for various nuclear safety-related pipelines. Combined with the power plant system design test and design parameter requirements, it satisfies the unidirectional flow resistance measurement for subsequent direct safety injection pipeline flow resistance tests between the IRWST water tank outlet and the reactor core in the CAP series nuclear power plant PXS system. However, the impact of the residual portion formed after the diaphragm in the flow passage section ruptures is still not adequately considered. Summary of the Invention

[0004] The purpose of this invention is to overcome the limitations of existing unidirectional flow simulation components with a centrally symmetrical cross-section structure. During fluid measurement, the unidirectional flow of this flow channel cross-section is difficult to be symmetrical with the burst valve diaphragm after bursting, thus reducing the simulation differences caused by this structure.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows: A unidirectional burst valve simulator includes a tubular shell with an internal flow channel. The tubular shell has a variable diameter flow channel along its interior. The variable diameter flow channel has an inlet section, a narrowing section, a minimum flow section, and an outlet section arranged sequentially along the flow direction of the fluid inside. At least one diaphragm simulator is arranged circumferentially in the minimum flow section. The diaphragm simulator is constructed as an arc-shaped protrusion located on the cross-section of the minimum flow section. The two sides of the arc-shaped protrusion are smoothly transitioned to and integrated with the minimum flow section. The cross-sectional area of ​​the arc-shaped protrusion gradually decreases along the fluid flow direction. Pressure taps are arranged circumferentially on the tubular shell.

[0006] As a preferred technical solution, the arc-shaped protrusion has a recess at one end near the inlet section and facing the outlet section, and the recess constitutes a flow resistance simulation cavity.

[0007] As a preferred technical solution, the depth of the pit is 10%-20% of the diameter of the minimum flow section.

[0008] As a preferred technical solution, the arc-shaped protrusions are distributed circumferentially on the cross-section of the tubular shell in 2-4 shapes.

[0009] As a preferred technical solution, the cross-section of the arc-shaped protrusion is the middle section of one side of the major axis of the virtual ellipse, and the included angle between the line connecting the center of two adjacent virtual ellipses and the center of the cross-section of the tubular shell is between 30° and 180°.

[0010] As a preferred technical solution, the cross-sectional areas of at least two of the arc-shaped protrusions on the same cross section are not equal.

[0011] As a preferred technical solution, the ratio of the radius of curvature of the arc-shaped protrusion to the diameter of the minimum flow section is 1:3 to 1:5.

[0012] As a preferred technical solution, the tubular shell is provided with connecting flanges at both ends.

[0013] As a preferred technical solution, at least one of the pressure tapping holes is configured to penetrate the arc-shaped protrusion and communicate with the variable diameter flow channel.

[0014] The advantages and beneficial effects of this invention are as follows: By setting an arc-shaped protrusion as a diaphragm simulator in the minimum flow section, the simulation discrepancy caused by the asymmetry between the existing centrally symmetrical simulator and the actual flow after the burst valve diaphragm bursts is effectively solved. The arc-shaped protrusion design mimics the asymmetric flow characteristics after the burst valve opens. Combined with the variable diameter flow channel and pressure tap, it can more accurately simulate the real flow resistance, improve the accuracy and reliability of pipeline flow parameter measurement, and ensure the integrity and sealing of the pipeline system during commissioning, meeting the requirements of flow resistance testing for nuclear power plant safety injection pipelines. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the longitudinal section structure of this utility model; Figure 2 This is a schematic diagram of the cross-sectional structure of this utility model; Figure label: 1-Tube shell, 2-Variable diameter flow channel, 3-Arc-shaped protrusion, 4-Pressure tap, 5-Dent, 6-Virtual ellipse, 7-Connecting flange. Detailed Implementation

[0016] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0017] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0018] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly or implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0019] Please see Figures 1-2 The technical solution provided in this embodiment includes a unidirectional burst valve simulator. Its basic structure consists of a tubular shell 1 with an internal flow channel. The tubular shell 1 has a variable-diameter flow channel 2 internally, which sequentially includes an inlet section, a converging section, a minimum flow section, and an outlet section along the fluid flow direction. At least one diaphragm simulator is circumferentially located in the minimum flow section. This diaphragm simulator is constructed as an arc-shaped protrusion 3 located on the cross-section of the minimum flow section. The two sides of the arc-shaped protrusion 3 smoothly transition into and are integrated with the minimum flow section. The cross-sectional area of ​​the arc-shaped protrusion 3 gradually decreases along the fluid flow direction. Simultaneously, pressure taps 4 are circumferentially distributed in the tubular shell 1. When the fluid flows through the minimum flow section, the asymmetric structure of the arc-shaped protrusion 3 disturbs the flow field, generating local flow separation and eddies, effectively simulating the non-uniform characteristics of the actual flow after the burst valve diaphragm bursts. The variable-diameter flow channel 2 guides the fluid through a smooth transition, reducing energy loss. The pressure taps 4 are used to collect pressure data at key locations, thereby more accurately reproducing the flow resistance performance of the real valve.

[0020] Specifically, the arc-shaped protrusion 3 is used to simulate the flow resistance caused by the residual structure after the diaphragm bursts during the operation of the explosion valve. Its asymmetrical arrangement is used to simulate the local obstacles formed after the real diaphragm tears and curls at a specific location. When high-speed fluid impacts the frontal surface of the arc-shaped protrusion 3, it will produce flow separation and vortex shedding phenomena similar to those caused by impacting the remnants of a real diaphragm. Its backal surface forms a low-pressure wake region, which together constitute a throttling and disturbance effect on the main flow field.

[0021] To generate local turbulence and enhance flow field non-uniformity in the minimum flow section, the technical solution provided in this embodiment includes a recess 5 formed at one end of the arc-shaped protrusion 3 near the inlet section and extending towards the outlet section. This recess 5 constitutes a flow resistance simulation cavity. The depth of the recess 5 is preferably 10%-20% of the diameter of the minimum flow section. When the fluid flows through the recess 5, a recirculation zone and low-pressure vortices are formed within the recess. These vortices interact with the main flow, more realistically simulating the complex flow field conditions at the moment the burst valve opens, effectively overcoming the flow resistance deviation of traditional simulation components.

[0022] In order to optimize the distribution and geometry of the diaphragm simulation components and ensure comprehensive simulation of asymmetric flow, the technical solution provided in this embodiment includes 2-4 arc-shaped protrusions 3 distributed circumferentially on the cross-section of the tubular shell 1.

[0023] Specifically, the geometry of the arc-shaped protrusion 3 is precisely defined by a "virtual ellipse 6". The major axis of the virtual ellipse 6 is parallel to the axis of the tubular shell 1, and its minor axis is set to 0.4 to 0.6 times the diameter of the minimum flow passage. The center of the virtual ellipse 6 is located on the inner wall contour line of the minimum flow passage. The cross-section of the arc-shaped protrusion 3 is the arc segment of the virtual ellipse 6 located on one side of its major axis, and its arc length ranges from 15% to 30% of the circumference of the virtual ellipse 6, thus forming a smooth protrusion structure similar to a teardrop.

[0024] The cross-section of the arc-shaped protrusion 3 is the middle section of one side of the major axis of the virtual ellipse 6, and its shape resembles a teardrop-shaped protrusion embedded in the inner wall of the tubular shell. The ratio of its radius of curvature to the diameter of the minimum flow section is 1:3 to 1:5. The angle between the line connecting the center of two adjacent virtual ellipses 6 and the center of the cross-section of the tubular shell 1 is in the range of 30°-180°. When the fluid passes through the minimum flow section, it experiences multi-directional disturbances, generating asymmetric shear layers and vortex streets, thus improving the fidelity of the flow resistance simulation.

[0025] To further enhance the asymmetric effect and adapt to different flow conditions, the technical solution provided in this embodiment includes at least two arc-shaped protrusions 3 with unequal cross-sectional areas on the same cross section. The simulator can accurately simulate the dynamic flow resistance characteristics of a real valve in unidirectional flow tests, reducing simulation errors. On the same cross section, the minor axis lengths of the virtual ellipses 6 corresponding to each arc-shaped protrusion 3 are different, or the lengths of their arc segments differ. For example, in a preferred embodiment, the minor axis of one of the two opposing arc-shaped protrusions 3 is 0.5 times the diameter of the minimum flow section, while the other is 0.4 times, resulting in different projected areas at the same axial position.

[0026] To facilitate installation and sealing, and ensure the integration of the simulator with the piping system, the technical solution provided in this embodiment includes connecting flanges 7 at both ends of the tubular shell 1. The connecting flanges 7 are connected to the external pipeline by bolts, providing mechanical strength and sealing assurance, enabling the simulator to operate stably under high pressure, while also facilitating disassembly and replacement, meeting the high-efficiency testing requirements of the nuclear power plant commissioning phase.

[0027] To directly monitor the flow pressure near the diaphragm simulator and obtain detailed flow field data, the technical solution provided in this embodiment includes at least one pressure tap 4 that penetrates the arc-shaped protrusion 3 and connects to the variable-diameter flow channel 2. The pressure tap 4 is located on the surface of the arc-shaped protrusion 3 or in the area of ​​the recess 5, directly sensing the pressure pulsation and eddy current effect of the fluid under the asymmetric structure; these data are collected by external sensors and used to simulate and calculate the flow resistance value to facilitate the analysis of turbulence characteristics.

[0028] It should be noted that the geometry, spatial distribution, and quantity of the arc-shaped protrusions 3 can be determined by inversion optimization based on transient fluid dynamics (CFD) numerical simulation and particle image velocimetry (PIV) experimental data of the actual diaphragm opening process of the burst valve. Through CFD simulation analysis of the unsteady flow behavior at the moment of diaphragm bursting, it was found that the diaphragm debris forms multiple asymmetric disturbance sources in the flow channel, inducing local flow separation and vortex shedding. Combined with the visual measurement of the flow structure by the PIV experiment, the key vortex core locations, shear layer evolution, and velocity distribution characteristics were identified. Based on the above fluid dynamics mechanism, parameters such as the radius of curvature, axial contraction gradient, and circumferential distribution angle of the arc-shaped protrusions were optimized in multiple rounds to ensure that the disturbance mode generated under steady-state flow conditions is consistent with the main characteristics of the actual burst transient flow, thereby achieving the reproduction of asymmetric flow resistance characteristics in the simulation.

[0029] The working principle of this invention is as follows: When fluid flows in from the inlet section of the tubular shell 1, it is accelerated through the converging section and enters the minimum flow section. The asymmetrically arranged arc-shaped protrusions 3 disturb the flow field, generating local flow separation and eddies, simulating the non-uniform flow state after the diaphragm of a real burst valve ruptures. The recess 5, as a flow resistance simulation cavity, further generates backflow and turbulence, increasing the complexity of the flow field. The gradient change of the variable diameter channel 2 reduces abrupt flow changes, and the pressure taps 4 collect pressure data at key locations for calculating flow resistance characteristics. Throughout the process, through the asymmetrical design of the arc-shaped protrusions, the turbulence mechanism of the recess, and the synergistic effect of the pressure taps, the actual flow resistance performance of the burst valve is accurately reproduced, providing an efficient and reliable testing method for unidirectional flow tests of nuclear power plant safety injection pipelines. The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A unidirectional burst valve simulation component, comprising a tubular shell (1) internally configured as a flow channel, wherein the tubular shell (1) has a variable diameter flow channel (2) internally configured, and the variable diameter flow channel (2) is sequentially provided with an inlet section, a converging section, a minimum flow section, and an outlet section along the flow direction of the fluid inside; characterized in that, At least one diaphragm simulation element is provided circumferentially in the minimum flow section. The diaphragm simulation element is constructed as an arc-shaped protrusion (3) located on the cross-section of the minimum flow section. The two sides of the arc-shaped protrusion (3) are smoothly transitioned and connected to the minimum flow section. Along the fluid flow direction, the cross-sectional area of ​​the arc-shaped protrusion (3) gradually decreases. The tubular shell (1) is provided with pressure tapping holes (4) circumferentially.

2. The unidirectional burst valve simulator according to claim 1, characterized in that, The arc-shaped protrusion (3) has a recess (5) at one end near the inlet section and extending toward the outlet section, and the recess (5) constitutes a flow resistance simulation cavity.

3. The unidirectional burst valve simulator according to claim 2, characterized in that, The depth of the pit (5) is 10%-20% of the diameter of the minimum flow section.

4. The unidirectional burst valve simulator according to claim 1, characterized in that, The arc-shaped protrusions (3) are distributed in 2-4 circles on the cross-section of the tubular shell (1).

5. The unidirectional burst valve simulator according to claim 4, characterized in that, The cross section of the arc-shaped protrusion (3) is the middle section of one side of the major axis of the virtual ellipse (6), and the angle between the line connecting the center of two adjacent virtual ellipses (6) and the center of the cross section of the tubular shell (1) is between 30° and 180°.

6. The unidirectional burst valve simulator according to claim 4 or 5, characterized in that, At least two of the arc-shaped protrusions (3) have unequal cross-sectional areas on the same cross section.

7. The unidirectional burst valve simulator according to claim 1, characterized in that, The ratio of the radius of curvature of the arc-shaped protrusion (3) to the diameter of the minimum flow section is 1:3 to 1:

5.

8. The unidirectional burst valve simulator according to claim 1, characterized in that, The tubular shell (1) is provided with connecting flanges (7) at both ends.

9. The unidirectional burst valve simulator according to claim 1, characterized in that, At least one of the pressure taps (4) is connected to the arc-shaped protrusion (3) and the variable diameter flow channel (2).

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