CN-122000101-A - System and method for measuring cavitation share of cross section of rod bundle

CN122000101ACN 122000101 ACN122000101 ACN 122000101ACN-122000101-A

Abstract

The invention discloses a system and a method for measuring cavitation share of a cross section of a rod bundle. The measuring system for the cavitation share of the cross section of the rod bundle comprises a tube body, a rod bundle assembly, a two-phase flow device, a first detecting component, a second detecting component and an image pickup component, wherein the rod bundle assembly is arranged in the tube body, the two-phase flow device is used for configuring gas-liquid two-phase flow substances and conveying the gas-liquid two-phase flow substances into a first cavity, the first detecting component is used for detecting pressure at a plurality of pressure measuring points in the first cavity and pressure difference between at least part of the pressure measuring points, the second detecting component is used for identifying the cavitation share of the cross section of the first cavity corresponding to the second detecting component, and the image pickup component is used for shooting the gas-liquid two-phase flow substances of a part of sections in the first cavity. The invention can simulate the flow characteristic of the steam-water flowing through the reactor core, and acquire parameters through various detection means, so as to further study the flow shape of the two-phase flow, calculate the section air content and qualitatively evaluate the friction pressure drop, and provide important support for measuring the cavitation share of the two-phase flow.

Inventors

LI HUIHUI
FAN PUCHENG
YANG FUMING
YUAN HAOWEI
FEI LIKAI
Peng Minyang
Fan guanhua
ZHANG SHUMING

Assignees

国家电投集团科学技术研究院有限公司
国电投科技孵化有限公司

Dates

Publication Date: 20260508
Application Date: 20241029

Claims (10)

1.A cavitation share measurement system for a cross-section of a bundle of rods, comprising: a tube having a first lumen, the tube extending in a first direction; a bundle assembly disposed within the first cavity; The outlet end of the two-phase flow device is communicated with the first cavity, and the two-phase flow device is used for configuring gas-liquid two-phase flow substances and conveying the gas-liquid two-phase flow substances into the first cavity; a first detection member coupled to the tubular body, the first detection member configured to detect a pressure at a plurality of pressure taps and a pressure differential between at least a portion of the pressure taps in the first cavity; A second detection component connected with the pipe body, the second detection component being used for identifying a section void fraction at the first cavity section corresponding to the second detection component; and the image pickup component is used for shooting the gas-liquid two-phase flow substance of a partial section in the first cavity so as to acquire a two-phase flow manifold.
2. The system for measuring void fraction of a cross-section of a bundle of rods of claim 1, wherein the bundle of rods comprises a spacer grid and a plurality of bundles of rods arranged in parallel and spaced apart relation, the bundles of rods extending in a first direction, the bundles of rods being connected to the tube through the spacer grid.
3. The share measurement system for a cross-section of a bundle of rods of claim 2, wherein each of the spacer grids is provided with pressure taps on both sides in the first direction; And/or the cross section of the first cavity is square, and a plurality of the bundles are arranged in a rectangular array of N x N; and/or the second detection part is arranged at the middle part or the middle lower part of the first cavity; And/or, the tube body is transparent.
4. A cavitation share measurement system for a rod bundle section according to any one of claims 1 to 3, wherein the first detection means is a differential pressure sensor having a plurality of stations arranged in a first direction within the first chamber to detect pressure at an inlet end of the first chamber and differential pressure between adjacent stations; and/or the second detection component is a line array sensor; and/or, the shooting component comprises a light source and a shooting instrument, and the light source and the shooting instrument are oppositely arranged.
5. The cavitation share measuring system for a rod cluster cross section of claim 1 wherein the first direction is vertical, the upper portion of the tube is provided with a first inlet, and the lower portion of the tube is provided with a first outlet.
6. The cavitation share measurement system for a rod cluster cross section of claim 1, wherein the two-phase flow device comprises: the outlet end of the mixer is connected with the inlet end of the pipe body, and the mixer is used for mixing gas-liquid two-phase substances; The gas supply assembly is connected with the mixer and is used for conveying gas into the mixer; And the liquid supply assembly is connected with the mixer and is used for conveying liquid into the mixer.
7. The cavitation share measurement system for a rod cluster cross section of claim 6, wherein the air supply assembly includes an air compressor, a gas line, and a first adjustment member provided on the gas line; The liquid supply assembly comprises a water tank, a water conveying pipeline, a first pump and a second adjusting part, wherein the first pump and the second adjusting part are arranged on the water conveying pipeline, and a water return pipeline is arranged between the outlet end of the pipe body and the water tank.
8. The cavitation share measurement system for a rod cluster cross section of claim 7, wherein the first adjustment component includes a pressure reducing valve, a gas flow meter, a gas flow rate adjustment valve and a first thermometer disposed on the gas line, the gas flow meter and gas flow rate adjustment valve being one or more groups disposed in parallel on the gas line; and/or the second regulating component comprises a first valve, a liquid flowmeter, a liquid flow regulating valve and a second thermometer which are arranged on the water conveying pipeline, wherein the liquid flowmeter and the liquid flow regulating valve are arranged in one group or in a plurality of groups which are arranged on the water conveying pipeline in parallel; and/or, the hydraulic pipeline further comprises a check valve, and the check valve is arranged on the hydraulic pipeline; And/or, the device further comprises a branch pipeline, wherein the branch pipeline is arranged between the liquid outlet end of the first pump and the water tank, and a second valve is arranged on the branch pipeline; And/or a baffle is arranged in the water tank to divide the inner cavity of the water tank into two water cavities, the upper parts of the two water cavities are communicated, an air outlet, a water inlet and a feeding port are arranged on the water tank, and a water outlet is arranged at the bottom of the water tank.
9. The cavitation share measurement system for a cross-section of a rod bundle of claim 1, further comprising a data acquisition and processing system coupled to the two-phase flow device, the first detection component, the second detection component, and the camera component to acquire acquisition data and process the data.
10. A method for measuring the cavitation share of a cross section of a bundle of rods, comprising the steps of: arranging the cavitation share measuring system for a cross section of a bundle of rods according to any one of claims 1 to 9, the tube extending in a vertical direction, the gas-liquid two-phase flow substance within the first cavity flowing from top to bottom; Configuring operation parameters of the two-phase flow device, and starting operation; Based on the formulas Δp=Δp fu +Δp a +Δp g and Δp g ＝-ρ m gh＝-[ρ g α+(1-α)ρ l ] gh, where Δp is the total pressure drop of the pipeline, Δp fu is the friction pressure drop in the vertical drop section, Δp a is the acceleration pressure drop, and Δp a ＝0,Δp g is the gravity pressure drop, ρ g is the gas phase density, ρ is the liquid phase density, ρ m is the two-phase flow average density, α is the section void fraction, as can be seen: Acquiring the total pressure drop delta p of the pipeline based on the detection data of the first detection component; The method comprises the steps of identifying a two-phase flow manifold based on the image pickup component, and obtaining friction pressure drop delta p fu in a vertical descending section by combining a first empirical relation, and/or adjusting the extending direction of the pipe body to a second direction which is orthogonal to the first direction, collecting detection data under the working condition and obtaining friction pressure drop delta p fu in the vertical descending section to verify the first warp customs examination system; The cross-sectional cavity fraction α is detected and compared with the cross-sectional cavity fraction detected by the second detection element.

Description

System and method for measuring cavitation share of cross section of rod bundle Technical Field The invention belongs to the technical field of nuclear power, and particularly relates to a system and a method for measuring cavitation share of a cross section of a rod bundle. Background The large break accident is a design benchmark accident of the nuclear power plant and is also one of key accidents required to be analyzed by the safety analysis software of the nuclear power plant. In order to fully mine the safety margin of the nuclear power plant design, the method generally adopts the best estimation and uncertainty to carry out the safety analysis of the large break accident, and a large number of tests are required to be carried out aiming at each stage of the large break accident to estimate and quantify the uncertainty. However, some of the test data may be obtained through collaborative approaches, but some key data is not available, affecting verification and popularization of the safety analysis software of the nuclear power plant. Disclosure of Invention The present invention has been made based on the findings and knowledge of the inventors regarding the following facts and problems: The inventors have recognized that when a large breach event occurs, the core fluid may quickly assume a two-phase state due to coolant loss, decreased flow rates, system depressurization, and the like. Analysis and research on two-phase flow and heat exchange phenomena of a typical pressurized water reactor core and accurate measurement on related parameters are key to acquiring verification and popularization data of nuclear power design safety analysis software. The inventor also realizes that the gas-liquid flow direction of the test section of the two-phase flow test device in the related art is from bottom to top, and mainly adopts the section cavitation share of a differential pressure measurement method, but when the two-phase flow flows from top to bottom in the test section, because of lack of knowledge of flow shape, when the cavitation share is calculated by adopting a differential pressure method, effective support is lacking. The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, embodiments of the present invention propose a cavitation share measurement system for a rod-bundle section that can be used for simulation and investigation of two-phase flow manifolds. According to an embodiment of the invention, a cavitation share measurement system for a cross section of a bundle of rods comprises: a tube having a first lumen, the tube extending in a first direction; a bundle assembly disposed within the first cavity; The outlet end of the two-phase flow device is communicated with the first cavity, and the two-phase flow device is used for configuring gas-liquid two-phase flow substances and conveying the gas-liquid two-phase flow substances into the first cavity; a first detection member coupled to the tubular body, the first detection member configured to detect a pressure at a plurality of pressure taps and a pressure differential between at least a portion of the pressure taps in the first cavity; A second detection component connected with the pipe body, the second detection component being used for identifying a section void fraction at the first cavity section corresponding to the second detection component; and the image pickup component is used for shooting the gas-liquid two-phase flow substance of a partial section in the first cavity so as to acquire a two-phase flow manifold. The cavitation share measuring system for the cross section of the rod bundle can simulate the flow characteristic of steam-water flowing through a reactor core, obtain parameters through various detection means, further study on two-phase flow manifold, calculation of cross section air content and qualitative assessment of friction pressure drop, and provide important support for cavitation share measurement of two-phase flow. In some embodiments, the bundle assembly includes a spacer grid and a plurality of bundles, the bundles being arranged in parallel and spaced apart relation, the bundles extending in a first direction, the bundles being connected to the tube through the spacer grid. In some embodiments, each of the spacer grids is provided with a pressure measurement point on both sides in the first direction; And/or the cross section of the first cavity is square, and a plurality of the bundles are arranged in a rectangular array of N x N; and/or the second detection part is arranged at the middle part or the middle lower part of the first cavity; And/or, the tube body is transparent. In some embodiments, the first detection component is a differential pressure sensor having a plurality of stations arranged in a first direction within the first cavity to detect a pressure at an inlet end of the first cavity and a pressure differential between adj