Test system and test method for ice plug of control rod drive wire of isotope production research reactor

Abstract

The invention provides an ice plug test system and method for a control rod drive wire of an isotope production research reactor, the test system comprises a mounting bracket and an ice plug forming mechanism, and a target test pipeline is mounted on the mounting bracket; one side of the mounting bracket is provided with a pressure pump and a water tank, one end of the pressure pump is connected with the water tank through a connecting pipeline, and the other end is communicated with a target test pipeline; the ice plug forming mechanism comprises a liquid nitrogen tank and an ice plug jacket assembly, the liquid nitrogen tank is connected with the ice plug jacket assembly through a conveying pipeline, the ice plug jacket assembly comprises a first splicing piece and a second splicing piece, and the first splicing piece and the second splicing piece are detachably clamped on the outer side of a target test pipeline; a cooling cavity is formed between the ice plug jacket assembly and the target test pipeline, and liquid nitrogen conveyed by the conveying pipeline flows through the cooling cavity to form an ice plug in the target test pipeline; the connecting pipeline is provided with a flowmeter, and the flowmeter is used for detecting the flow of water flowing out of the target test pipeline so as to determine the ice plug forming state of the target test pipeline.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear reactor maintenance, and particularly relates to an ice plug test system and test method for a control rod drive line of an isotope production research reactor. Background Art

[0002] An isotope production research reactor is a pool-type reactor that uses enriched uranium as fuel. The reactor core is placed at the bottom of the pool or suspended in the pool. When the reactor core is suspended in the pool, it can move within the pool, hence the name of the pool-type reactor.

[0003] It can be known that purified water is contained in the pool, which can be used as a moderator, coolant, reflector and part of the shielding layer material. Heavy concrete shielding layers are poured on the sides and bottom of the pool. The characteristics of the pool-type reactor are simple and economical construction, flexible and convenient use, and can meet various engineering or physical test requirements.

[0004] In such a pool-type reactor, pipelines are an important internal component, which need to withstand high temperature, high pressure and radiation environment, and are responsible for transporting reactor core cooling water, fluid media, controlling reactor operation and ensuring reactor safety.

[0005] The pipelines of this reactor mainly include control rod drive mechanism pipelines, coolant pipelines, fuel delivery pipelines, and other auxiliary pipelines, etc. These pipelines undertake different functions in the reactor. However, in order to ensure the safe and stable operation of the internal pipelines of the reactor, regular maintenance and overhaul of the pipelines are required.

[0006] When the pipelines need to be removed for maintenance, the traditional method requires isolation of the upstream and downstream or draining the liquid in the entire pipeline system or even forced shutdown of the whole plant, which brings great difficulties to maintenance and generates large economic and time costs.

[0007] With the development of cryogenic engineering technology, the ice plug freezing and plugging technology has emerged as an effective system isolation technology. Its working principle is to locally cool the system pipelines through a refrigerant, so that the liquid medium in the pipe section solidifies into ice, forming an "ice plug" that can withstand high pressure, thereby achieving isolation between the upstream and downstream.

[0008] Traditional ice plug forming devices only satisfy the formation of ice plugs in single pipes, and only use cameras to monitor the general process of ice plug formation in single pipes. At the same time, they cannot take into account various factors such as pipeline heat transfer, flow rate, temperature and energy conservation, and cannot accurately obtain the change state of the entire cycle of ice plug formation.

[0009] The control rod drive pipeline of the isotope production research reactor is different from the conventional pipeline. The pipeline is divided into a double-layer structure of an inner pipe and an outer pipe, and the nuclear reactor has high requirements for the maintenance efficiency. Therefore, it is necessary to more accurately know the formation process of the ice plug in the control rod drive pipeline under different conditions, and the existing ice plug devices cannot meet this requirement.

[0010] Based on this, the inventor of the present application proposes an ice plug test system and test method for the control rod drive line of the isotope production research reactor in order to solve the above technical problems. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to overcome the defect that the current ice plug forming device in the prior art cannot meet the monitoring of the ice plug forming process of the control rod drive pipeline, and to provide an ice plug test system for the control rod drive line of the isotope production research reactor.

[0012] The present invention solves the above technical problems through the following technical solutions:

[0013] In the first aspect of the present invention, there is provided an ice plug test system for the control rod drive line of the isotope production research reactor, which is characterized by including:

[0014] A mounting bracket on which a target test pipeline is installed;

[0015] On one side of the mounting bracket, there are a pressure pump and a water tank. One end of the pressure pump is connected to the water tank through a connecting pipeline, and the other end is communicated with the target test pipeline;

[0016] An ice plug forming mechanism, including a liquid nitrogen tank and an ice plug jacket assembly. The liquid nitrogen tank is connected to the ice plug jacket assembly through a conveying pipeline. The ice plug jacket assembly includes a first splicing part and a second splicing part. The first splicing part and the second splicing part are detachably clamped on the outside of the target test pipeline. A cooling cavity is formed between the ice plug jacket assembly and the target test pipeline. The liquid nitrogen conveyed through the conveying pipeline flows through the cooling cavity to form an ice plug in the target test pipeline; wherein,

[0017] A flow meter is provided on the connecting pipeline, and the flow meter is used to respectively detect the flow rate of the water flowing out of the target test pipeline to determine the ice plug formation state of the target test pipeline.

[0018] According to an embodiment of the present invention, the target test pipeline includes an inner pipe and an outer pipe sleeved outside the inner pipe. A flow chamber is formed between the inner pipe and the outer pipe, and one end of the connecting pipeline is respectively communicated with the inner pipe and the flow chamber.

[0019] According to an embodiment of the present invention, the connecting pipeline includes a first connecting pipe group and a second connecting pipe group. The pressure pump, the water tank, and the inner pipe are connected through the first connecting pipe group;

[0020] The pressure pump, the water tank, and the flow chamber are connected through the second connecting pipe group;

[0021] The flow meters are respectively arranged on the first connecting pipe group and the second connecting pipe group.

[0022] According to an embodiment of the present invention, the number of the pressure pumps is two, namely a first pressure pump and a second pressure pump;

[0023] The first connecting pipe group includes a first pipe, a second pipe, and a third pipe. One end of the first pipe is communicated with the water tank, and the other end is connected to the first pressure pump. One end of the second pipe is connected to the first pressure pump, and the other end is connected to the inner pipe. One end of the third pipe is connected to the inner pipe, and the other end is communicated with the water tank. Wherein, the connection position of the second pipe and the inner pipe is above the connection position of the third pipe and the inner pipe;

[0024] The second connecting pipe group includes a fourth pipe, a fifth pipe, and a sixth pipe. One end of the fourth pipe is communicated with the water tank, and the other end is connected to the second pressure pump. One end of the fifth pipe is connected to the second pressure pump, and the other end is communicated with the flow chamber. One end of the sixth pipe is communicated with the flow chamber, and the other end is communicated with the water tank. Wherein, the connection position of the fifth pipe and the outer pipe is above the connection position of the sixth pipe and the outer pipe;

[0025] The first pressure pump and the second pressure pump operate independently.

[0026] According to an embodiment of the present invention, the target test pipeline is vertically arranged on the installation bracket;

[0027] The connection position of the second pipe and the inner pipe and the connection position of the fourth pipe and the outer pipe are at least above the ice plug jacket assembly.

[0028] According to an embodiment of the present invention, the flow meters are respectively arranged on the third pipe and the sixth pipe.

[0029] According to an embodiment of the present invention, an infrared camera is further arranged on the target test pipeline. One end of the infrared camera extends into the flow chamber to monitor the formation process of the ice plug in the flow chamber.

[0030] According to an embodiment of the present invention, a control mechanism is further provided between the liquid nitrogen tank and the ice plug jacket assembly, and the control mechanism is used to control the liquid nitrogen flow rate flowing from the conveying pipeline to the ice plug jacket assembly.

[0031] According to an embodiment of the present invention, a temperature sensor is provided in the water tank to monitor the temperature of the water flowing into the target test pipeline.

[0032] The second aspect of the present invention provides an ice plug test method for the control rod drive line of an isotope production research reactor, which is implemented by using the ice plug test system for the control rod drive line of the isotope production research reactor as described above. The test method includes:

[0033] Step 1: Install the target test pipeline on the installation bracket, and install the ice plug jacket assembly outside the target test pipeline.

[0034] Step 2: Open the pressure pump to enable water circulation between the inner pipe and the circulation chamber and the water tank respectively.

[0035] Step 3: Open the liquid nitrogen tank for testing, and use a flow meter and / or an infrared camera to record the ice plug formation time in the inner pipe and the circulation chamber.

[0036] Step 4: Repeat the test by changing at least one of the water temperature in the water tank, the water flow rate and flow volume flowing through the pressure pump to the inner pipe and the circulation chamber, and the flow rate of the liquid nitrogen delivered to the ice plug jacket, so as to determine the ice plug formation time of the target test pipeline under different external conditions.

[0037] The positive and progressive effects of the present invention are as follows:

[0038] For the ice plug test system of the control rod drive line of the isotope production research reactor of the present invention, the target test pipeline is installed by using the installation bracket, and the pressure water pump, the water tank and the target test pipeline are connected through the connecting pipeline, so as to form a circulation between the target test pipeline and the water tank respectively, simulating the actual operation state of the target test pipeline.

[0039] In the test system of the present invention, the ice plug jacket assembly includes a first splicing part and a second splicing part that are detachably arranged. Thus, local cooling can be carried out on the control rod drive line of the research reactor that needs to be repaired to form an ice plug that can withstand high pressure. And a flow meter is provided on the connecting pipeline. The freezing state in the target test pipeline can be determined by the pumping speed of the pressure pump and the flow volume measured by the flow meter. This determination method can form an ice plug at the target position as needed, has a wider applicable environment, and is conducive to obtaining the ice plug formation process more accurately. Description of the Drawings

[0040] The above and other features, properties, and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings and embodiments, where:

[0041] Figure 1 is a schematic structural diagram of the ice plug test system for the control rod drive line of the isotope production research reactor of the present invention;

[0042] Figure 2 is Figure 1 a schematic layout diagram of the pressure pump, water tank, and target test pipeline at an angle in

[0043] Figure 3 is Figure 1 a simplified layout diagram of the connecting pipelines between the pressure pump, water tank, and target test pipeline in

[0044] Figure 4 is a cross-sectional view of the target test pipeline of the present invention;

[0045] Figure 5 is a flowchart of the ice plug test method for the control rod drive line of the isotope production research reactor of the present invention.

[0046] 1. Installation bracket; 11. Target test pipeline; 111. Inner pipe; 112. Outer pipe; 113. Flow-through chamber; 114. Infrared camera;

[0047] 2. Pressure pump; 21. Connecting pipeline; 211. Flowmeter; 212. First connecting pipe group; 213. Second connecting pipe group; 214. First pipeline; 215. Second pipeline; 216. Third pipeline; 217. Fourth pipeline; 218. Fifth pipeline; 219. Sixth pipeline; 22. First pressure pump; 23. Second pressure pump;

[0048] 3. Water tank; 31. Temperature sensor;

[0049] 4. Ice plug forming mechanism; 41. Liquid nitrogen tank; 42. Ice plug jacket assembly; 421. First assembled part; 422. Second assembled part; 423. Cooling chamber; 43. Delivery pipeline; 44. Control mechanism. Detailed implementation manners

[0050] The present invention will be further described below in conjunction with specific embodiments and the accompanying drawings. More details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from this description. Those skilled in the art can make similar generalizations and deductions according to the actual application situation without departing from the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0052] Please refer to Figures 1 to 4 , the present invention provides an ice plug test system for the control rod drive line of an isotope production research reactor, which includes a mounting bracket 1 and an ice plug forming mechanism 4. A target test pipeline 11 is installed on the mounting bracket 1. A pressure pump 2 and a water tank 3 are provided on one side of the mounting bracket 1. One end of a connecting pipeline 21 of the pressure pump 2 is connected to the water tank 3, and the other end is communicated with the target test pipeline 11.

[0053] The target test pipeline 11 includes an inner pipe 111 and an outer pipe 112 sleeved outside the inner pipe 111. A flow chamber 113 is formed between the inner pipe 111 and the outer pipe 112.

[0054] The ice plug forming mechanism 4 includes a liquid nitrogen tank 41 and an ice plug jacket assembly 42. The liquid nitrogen tank 41 is connected to the ice plug jacket assembly 42 through a conveying pipeline 43. The ice plug jacket assembly 42 includes a first fitting 421 and a second fitting 422. The first fitting 421 and the second fitting 422 are detachably clamped on the outside of the target test pipeline 11; a cooling chamber 423 is formed between the ice plug jacket assembly 42 and the target test pipeline 11. The liquid nitrogen conveyed through the conveying pipeline 43 flows through the cooling chamber 423 to form an ice plug in the target test pipeline 11.

[0055] The first fitting 421 and the second fitting 422 can be connected through a threaded connector, and the cooling chamber 423 is a closed chamber, thereby avoiding leakage of the filled cooling medium and improving the ice plug forming efficiency.

[0056] It should be noted that the ice plug jacket assembly 42 adopts the cooperation mode of the first fitting 421 and the second fitting 422. On the one hand, it is convenient for installation and can be installed at the required position according to requirements, with stronger flexibility. On the other hand, a cooling chamber 423 is formed between the first fitting 421 and the second fitting 422. The cooling chamber 423 can temporarily store the liquid nitrogen, slow down the flow rate of the liquid nitrogen flowing through the target test pipeline 11, quickly cool the part of the target test pipeline 11 where the ice plug jacket assembly 42 is installed, reduce the waste amount of the liquid nitrogen, have good environmental protection performance and can achieve fast and accurate isolation.

[0057] It can be known that the ice plug jacket assemblies 42 with corresponding sizes can be pre-designed for the target test pipelines 11 with different pipe diameters. A heat-conducting adhesive is also arranged at the inner end of the ice plug jacket assembly 42, and the heat-conducting adhesive is closely attached to the outer wall of the outer pipe 112 to improve the heat conduction efficiency, so that the target test pipeline 11 can be cooled quickly.

[0058] In one embodiment, a flowmeter 211 is provided on the connecting pipeline 21. The flowmeter 211 is used to detect the flow rates of the water flowing out through the inner pipe 111 and the flow chamber 113 respectively to determine the ice plug formation state of the target test pipeline 11.

[0059] The existing ice plug formation devices have relatively simple structures and are limited to forming ice plugs on single pipes. Moreover, the ice plug formation process is generally monitored by a camera. Specifically, by inserting the observation end of the camera into the pipeline, at the initial stage of ice plug formation, the images captured by the camera will be seriously interfered by water, and it is impossible to determine whether the ice plug has been formed. Only in the middle stage of ice plug formation, after the water flow rate becomes smaller, the ice plug can be clearly observed from the images taken by the camera. Therefore, using only the camera cannot completely record the complete time of ice plug formation.

[0060] In the field of nuclear reactor maintenance, especially for the control rod drive line, strictly controlling the ice plug formation time is beneficial to improving the nuclear reactor maintenance efficiency.

[0061] Based on this, the present application proposes an ice plug test system. The target test pipeline 11 is placed on the installation bracket 1 for testing, and at the same time, the flowmeter 211 is used to determine the ice plug formation state of the target test pipeline 11. Among them, the target test pipeline 11 can be pipelines made of different materials and with different pipe diameters. For example, multiple target test pipelines 11 can be manufactured in advance for testing to provide a reference for the selection of the pipeline material and pipe diameter of the control rod drive line according to the test results.

[0062] That is to say, the existing ice plug formation devices do not consider whether the stress generated during ice plug formation causes damage to the pipelines made of different materials and affects their service lives.

[0063] In the field of nuclear reactor maintenance where the present application is located, there are high requirements for the service life of pipelines. Therefore, the test system set up in the present application can test the target test pipelines 11 made of different materials and with different pipe diameters. After each test, the target test pipeline 11 can be removed and its fatigue life analyzed to determine whether the formation of the ice plug causes damage to the pipeline itself, so as to provide data reference for the selection of the pipeline material and the determination of the pipe diameter of the control rod drive line. Among them, the pipeline fatigue life analysis belongs to the commonly used life analysis means in this field and will not be elaborated here.

[0064] Please refer to Figure 4, because the control rod drive line has an inner and outer layer structure, the pressure pump 2 forms a water cycle with the inner tube 111 and the flow chamber 113 respectively through the connecting pipe 21 and the water tank 3 to monitor the ice plug formation states in the inner tube 111 and the flow chamber 113 respectively. The test state of the target test pipe 11 is consistent with the actual operating state of the control rod drive line, so the test data is more reliable.

[0065] Because the method of using a camera to monitor the ice plug formation state in the traditional ice plug formation device is not applicable to the control rod drive line of this application, and the accuracy of the camera monitoring method is very low, and the ice plug formation time cannot be accurately obtained.

[0066] Based on this, this application monitors the ice plug formation state through the flowmeter 211. That is, the icing states in the inner tube 111 and the flow chamber 113 of the target test pipe 11 can be determined by the flow rate measured by the flowmeter 211.

[0067] Alternatively, in some other embodiments, it is also possible to determine whether the target test pipe 11 is frozen by the pumping speed and flow rate of the pressure pump 2.

[0068] Traditionally, ice plugs are formed on a single pipe and monitored by a camera, which is not applicable to the monitoring of the double pipes in this application, and the camera cannot determine the entire cycle state of ice plug formation. That is, in the initial stage of ice plug formation, the images observed or taken by the camera are not much different from those without ice plug formation due to the interference of water flow, and the state changes of the ice plug from the initial stage to the completion of the entire cycle cannot be known.

[0069] In this application, the ice plug formation state is detected by flow rate. In the initial stage of ice plug formation, the flow rate will decrease until the flow stops. When the ice plug is formed, monitoring by flow rate can very intuitively determine the entire time from the initial stage to the completion of ice plug formation.

[0070] Please continue to refer to Figure 2 and Figure 3 , for the target test pipe 11 of the present invention, the connecting pipe 21 includes a first connecting pipe group 212 and a second connecting pipe group 213. The pressure pump 2, the water tank 3 and the inner tube 111 are connected through the first connecting pipe group 212; the pressure pump 2, the water tank 3 and the flow chamber 113 are connected through the second connecting pipe group 213; flowmeters 211 are respectively provided on the first connecting pipe group 212 and the second connecting pipe group 213.

[0071] It can be seen that the first connecting pipe group 212 and the second connecting pipe group 213 operate independently. The pressure pump 2, the water tank 3 and the inner tube 111 are connected through the first connecting pipe group 212, so that a water cycle can be formed in the inner tube 111 to simulate the actual operating state of the inner tube 111.

[0072] Similarly, the pressure pump 2, the water tank 3, and the circulation chamber 113 are connected by a second connecting pipe group 213, thereby forming a water cycle in the circulation chamber 113 to simulate the actual operating state of the circulation chamber 113.

[0073] Further, the number of pressure pumps 2 is two, namely the first pressure pump 22 and the second pressure pump 23 respectively; the first connecting pipe group 212 includes a first pipe 214, a second pipe 215, and a third pipe 216. One end of the first pipe 214 is communicated with the water tank 3, and the other end is connected to the first pressure pump 22. One end of the second pipe 215 is connected to the first pressure pump 22, and the other end is connected to the inner pipe 111. One end of the third pipe 216 is connected to the inner pipe 111, and the other end is communicated with the water tank 3; wherein, the connection position of the second pipe 215 and the inner pipe 111 is above the connection position of the third pipe 216 and the inner pipe 111; the second connecting pipe group 213 includes a fourth pipe 217, a fifth pipe 218, and a sixth pipe 219. One end of the fourth pipe 217 is communicated with the water tank 3, and the other end is connected to the second pressure pump 23. One end of the fifth pipe 218 is connected to the second pressure pump 23, and the other end is communicated with the circulation chamber 113. One end of the sixth pipe 219 is communicated with the circulation chamber 113, and the other end is communicated with the water tank 3; wherein, the connection position of the fifth pipe 218 and the outer pipe 112 is above the connection position of the sixth pipe 219 and the outer pipe 112; the first pressure pump 22 and the second pressure pump 23 operate independently.

[0074] That is to say, the first pressure pump 22 sucks the water in the water tank 3 through the first pipe 214, then pumps the water to the inner pipe 111 by using the second pipe 215, and the water in the inner pipe 111 flows back to the water tank 3 through the third pipe 216, thereby forming a water cycle in the inner pipe 111.

[0075] Similarly, the second pressure pump 23 sucks the water in the water tank 3 through the fourth pipe 217, then pumps the water to the circulation chamber 113 by using the fifth pipe 218, and the water in the circulation chamber 113 flows back to the water tank 3 through the sixth pipe 219, thereby forming a water cycle in the circulation chamber 113.

[0076] Through the settings of the first pressure pump 22 and the second pressure pump 23, water cycles are formed in both the inner pipe 111 and the circulation chamber 113, fully simulating the actual operating state of the control rod drive line, and enhancing the authenticity and reliability of the test.

[0077] Further, the target test pipe 11 is vertically arranged on the mounting bracket 1; the connection position of the second pipe 215 and the inner pipe 111 and the connection position of the fourth pipe 217 and the outer pipe 112 are at least above the ice plug jacket assembly 42.

[0078] Since the actual arrangement state of the control rod drive line is vertically set, the target test pipeline 11 is installed on the installation bracket 1 vertically in this application, which is consistent with the actual placement state of the control rod drive line. Moreover, the connection positions of the second pipeline 215 and the inner pipe 111 and the connection positions of the fourth pipeline 217 and the outer pipe 112 are at least above the ice plug jacket assembly 42 to ensure that water flows through the ice plug jacket assembly 42, thereby meeting the formation conditions of the ice plug.

[0079] It should be noted that the flow meters 211 are respectively arranged on the third pipeline 216 and the sixth pipeline 219.

[0080] The flow meters 211 can respectively measure the flow rate of the water flowing out of the inner pipe 111 in the third pipeline 216 and the flow rate of the water flowing out of the flow chamber 113 in the sixth pipeline 219. The formation state of the ice plug in the inner pipe 111 and the flow chamber 113 can be determined through the change value of the water flow rate.

[0081] That is, according to the flow data, this application can know the accurate time of ice plug formation, which is beneficial to improving the efficiency of nuclear reactor maintenance.

[0082] Please continue to refer to Figure 1 and Figure 2 , an infrared camera 114 is also provided on the target test pipeline 11. One end of the infrared camera 114 extends into the flow chamber 113 to monitor the formation process of the ice plug in the flow chamber 113.

[0083] The infrared camera 114 is used to monitor the formation of the ice plug inside the flow chamber 113 of the target test pipeline 11 in real time, the change of the external frost line and the temperature change. The detection results can be connected to a computer terminal, thereby effectively realizing online isolation and avoiding production losses caused by the shutdown of the pipeline system.

[0084] This application uses the infrared camera 114 and the flow meter 211 to cooperate to monitor the formation state of the ice plug, so that the formation time of the ice plug in the inner pipe 111 and the flow chamber 113 can be accurately known.

[0085] In one embodiment, a control mechanism 44 is further provided between the liquid nitrogen tank 41 and the ice plug jacket assembly 42. The control mechanism 44 is used to control the liquid nitrogen flow rate flowing from the delivery pipeline 43 to the ice plug jacket assembly 42.

[0086] That is, the control mechanism 44 can control the flow rate and flow of the liquid nitrogen to prevent safety accidents caused by excessive liquid nitrogen delivery. The control mechanism 44 can be a control valve or a control box and other structures, which are not limited here. Taking the control box as an example, the liquid nitrogen transported by the liquid nitrogen tank 41 can be redistributed in the control box, and then the flow rate is controlled and then transported to the ice plug jacket assembly 42.

[0087] In one embodiment, a temperature sensor 31 is provided in the water tank 3 to monitor the temperature of the water flowing to the target test pipeline 11.

[0088] By observing the temperature sensor 31, water at different temperatures can be injected into the water tank 3 for testing, and thus the time for ice plugs to form in the target test pipeline 11 with water at different temperatures can be obtained.

[0089] In a pool-type reactor, the pipeline is an important internal component that needs to withstand high temperature, high pressure and radiation environment, and is responsible for transporting the core cooling water, fluid medium, controlling the reactor operation and ensuring the reactor safety.

[0090] The ice plug test system proposed in this application can select target test pipelines 11 made of different materials for installation and testing as needed. According to the test results, the formation state of ice plugs under different materials and whether the ice plugs will cause damage to the pipelines themselves can be known, and thus the pipeline materials that meet the use requirements of ice plug freezing and plugging can be obtained. Among them, after each test, the fatigue life of the target test pipeline 11 can be analyzed to determine whether the formation of ice plugs causes damage to the pipeline itself.

[0091] Moreover, a flowmeter 211 and an infrared camera 114 are provided in this application. When used in cooperation, the formation state of the entire cycle of the ice plug in the inner pipe 111 and the flow chamber 113 of the target test pipeline 11 can be accurately known, including the formation time, the shape of the ice plug formed in the flow chamber 113, etc.

[0092] In addition, a control mechanism 44 is provided between the liquid nitrogen tank 41 and the ice plug jacket assembly 42. The control mechanism 44 can control and real-time monitor the delivery flow rate of liquid nitrogen, and deliver liquid nitrogen to the ice plug jacket assembly 42 to freeze the liquid in the target test pipeline 11.

[0093] By adjusting the delivery flow rate of liquid nitrogen, and using the flowmeter 211 and the infrared camera 114, the influence on the formation of ice plugs under different delivery flow rates of liquid nitrogen can be determined, and moreover, it can avoid safety accidents caused by excessive delivery of liquid nitrogen and damage to the target test pipeline 11.

[0094] Moreover, a temperature sensor 31 is provided in the water tank 3, so that tests can be carried out with different water temperatures, and then the length of the formation time of ice plugs under different water temperatures can be compared.

[0095] That is to say, the test system of this application satisfies the ice plug formation tests under different pipeline materials, pipe diameters, water temperatures, liquid nitrogen delivery flow rates, water flow directions, water pressures and other variables. The test results are beneficial to providing data support for improving the maintenance efficiency of nuclear reactors, ensuring the safety, reliability and service life of nuclear reactor equipment.

[0096] Refer to Figure 5, the present invention also provides a method for the ice plug test of the control rod drive line of an isotope production research reactor, which is realized by using the above-mentioned ice plug test system for the control rod drive line of an isotope production research reactor. The test method includes:

[0097] S1. Install the target test pipeline on the installation bracket, and install the ice plug jacket assembly outside the target test pipeline;

[0098] S2. Open the pressure pump to enable water circulation between the inner pipe and the flow chamber and the water tank respectively;

[0099] S3. Open the liquid nitrogen tank for the test, and record the ice plug formation time in the inner pipe and the flow chamber by using a flow meter and / or an infrared camera;

[0100] S4. Repeat the test by changing at least one of the water temperature in the water tank, the water flow rate and flow to the inner pipe and the flow chamber through the pressure pump, and the flow rate of the liquid nitrogen delivered to the ice plug jacket, so as to determine the ice plug formation time of the target test pipeline under different external conditions.

[0101] Through the above test method, the present application is beneficial to knowing the suitable pipeline materials for the control rod drive line that meet the ice plug sealing, and can monitor the complete cycle of ice plug formation, thereby being beneficial to improving the maintenance efficiency of the nuclear reactor and ensuring the safety, reliability and service life of the nuclear reactor equipment.

[0102] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0103] The present application uses specific words to describe the embodiments of the present application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification is not necessarily the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application can be combined appropriately.

[0104] Although the present invention is disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, all modifications, equivalent changes and decorations made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. An isotope production research reactor control rod drive line ice plug test system, characterized in that: include: A mounting bracket, on which a target test pipe is mounted; A pressure pump and a water tank are provided on one side of the mounting bracket, wherein one end of the pressure pump is connected to the water tank via a connecting pipe, and the other end is connected to the target test pipe; An ice plug forming mechanism comprises a liquid nitrogen tank and an ice plug jacket assembly, wherein the liquid nitrogen tank is connected to the ice plug jacket assembly via a delivery pipeline, the ice plug jacket assembly comprises a first assembly and a second assembly, the first assembly and the second assembly are detachably mounted on the outside of the target test pipeline, a cooling chamber is formed between the ice plug jacket assembly and the target test pipeline, and the liquid nitrogen delivered via the delivery pipeline flows through the cooling chamber to form an ice plug in the target test pipeline; wherein, A flow meter is provided on the connecting pipeline, and the flow meter is used to respectively detect the flow rate of water flowing out of the target test pipeline to determine the ice plug formation state of the target test pipeline.

2. The isotope production research reactor control rod drive line ice plugging test system according to claim 1, characterized in that: The target test pipeline includes an inner tube and an outer tube sleeved outside the inner tube, a flow chamber is formed between the inner tube and the outer tube, and one end of the connecting pipeline is connected to the inner tube and the flow chamber respectively.

3. The isotope production research reactor control rod drive line ice plugging test system according to claim 2, characterized in that: The connecting pipeline includes a first connecting pipe group and a second connecting pipe group, and the pressure pump, the water tank and the inner pipe are connected through the first connecting pipe group; The pressure pump, the water tank and the circulation chamber are connected via the second connecting pipe group; The flow meter is respectively disposed on the first connecting pipe group and the second connecting pipe group.

4. The isotope production research reactor control rod drive line ice plugging test system according to claim 3, characterized in that: The number of the pressure pumps is two, which are respectively a first pressure pump and a second pressure pump; The first connecting pipe group includes a first pipe, a second pipe and a third pipe, wherein one end of the first pipe is connected to the water tank, and the other end is connected to the first pressure pump, one end of the second pipe is connected to the first pressure pump, and the other end is connected to the inner pipe, and one end of the third pipe is connected to the inner pipe, and the other end is connected to the water tank; wherein the connection position of the second pipe and the inner pipe is above the connection position of the third pipe and the inner pipe; The second connecting pipe group includes a fourth pipe, a fifth pipe and a sixth pipe, one end of the fourth pipe is connected to the water tank, and the other end is connected to the second pressure pump, one end of the fifth pipe is connected to the second pressure pump, and the other end is connected to the flow chamber, and one end of the sixth pipe is connected to the flow chamber, and the other end is connected to the water tank; wherein the connection position of the fifth pipe and the outer pipe is above the connection position of the sixth pipe and the outer pipe; The first pressure pump and the second pressure pump operate independently of each other.

5. The isotope production research reactor control rod drive line ice plugging test system according to claim 4, characterized in that: The target test pipeline is vertically arranged on the mounting bracket; The connection position between the second pipe and the inner pipe and the connection position between the fourth pipe and the outer pipe are at least located above the ice plug jacket assembly.

6. The isotope production research reactor control rod drive line ice plugging test system according to claim 4, characterized in that: The flow meters are respectively arranged on the third pipeline and the sixth pipeline.

7. The isotope production research reactor control rod drive line ice plugging test system according to claim 2, characterized in that: The target test pipeline is also provided with an infrared camera, one end of which extends into the flow chamber to monitor the formation process of ice plugs in the flow chamber.

8. The isotope production research reactor control rod drive line ice plugging test system according to claim 1, characterized in that: A control mechanism is also provided between the liquid nitrogen tank and the ice plug jacket assembly, and the control mechanism is used to control the flow rate of liquid nitrogen from the delivery pipeline to the ice plug jacket assembly.

9. The isotope production research reactor control rod drive line ice plugging test system according to claim 1, characterized in that: A temperature sensor is disposed in the water tank to monitor the temperature of water flowing to the target test pipeline.

10. An isotope production research reactor control rod drive line ice plugging test method, characterized in that: The method is implemented by using the isotope production research reactor control rod drive line ice jam test system according to any one of claims 1 to 9, wherein the test method comprises: Step 1: Install the target test pipe on the mounting bracket, and install the ice plug jacket assembly on the outside of the target test pipe; Step 2, turning on the pressure pump to allow water to circulate between the inner tube and the circulation chamber and the water tank respectively; Step 3, opening the liquid nitrogen tank to conduct a test, and using a flow meter and / or an infrared camera to record the time when ice plugs are formed in the inner tube and the flow chamber; Step 4, repeat the test by changing at least one of the water temperature in the water tank, the water flow rate and flow rate flowing to the inner tube and the flow chamber through the pressure pump, and the flow rate of liquid nitrogen delivered to the ice plug jacket, so as to determine the ice plug formation time of the target test pipeline under different external conditions.

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