Overvoltage protection design method for irradiation test loop

Abstract

The invention provides an overpressure protection design method for an irradiation test loop, and belongs to the technical field of research reactor irradiation, and the overpressure protection design method for the irradiation test loop comprises the steps: constructing a first model of the irradiation test loop, and constructing a second model of the irradiation test loop; assuming a starting condition causing overpressure protection and a boundary condition of the overpressure protection device, when the leakage detection system is overpressure, the pressure of the leakage detection system does not exceed the pressure bearing limit of the heat insulation pipe by adjusting the sectional area of the spraying section and the spraying starting time of the overpressure protection device; the appropriate overpressure protection device is selected according to the calculated spraying sectional area size and the calculated spraying delay starting time, pressure relief is carried out on an irradiation test loop in time, the pressure of a leakage detection system is prevented from exceeding the pressure bearing limit of a heat insulation pipe, and the leakage detection reliability of the heat insulation pipe is improved. And the working safety and reliability of the irradiation test loop are ensured.

Description

Technical Field

[0001] The present application belongs to the field of research reactor irradiation technology, and specifically relates to an irradiation test circuit overpressure protection design method. Background Art

[0002] As a performance verification platform for fuel elements and material elements, the irradiation test loop can provide real operating conditions of high temperature and high pressure for fuel elements and material elements. After the irradiation device of the test loop is loaded with the test object, it is inserted into the research reactor. On the one hand, it serves as the pressure boundary of the research reactor, and on the other hand, it also serves as the pressure boundary of the test loop. Once a leak occurs on the high-pressure side of the test loop, it will affect the safe operation of the research reactor. It is necessary to establish an overpressure protection facility in the irradiation test loop. Whether the capacity of the overpressure protection facility can meet the needs under various working conditions affects the safety and reliability of the operation of the irradiation test system. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] In view of this, according to an embodiment of the present application, a method for designing overpressure protection of an irradiation test circuit is proposed, including:

[0005] Construct the first model of the irradiation test circuit and determine the installation location of the overpressure protection device;

[0006] Determine the initial boundary conditions of the overpressure protection device and select the initiating event that causes overpressure protection;

[0007] Calculate the spraying cross-sectional area of ​​the overpressure protection device and calculate the spraying delay start time of the overpressure protection device.

[0008] In a feasible implementation, the steps of constructing a first model of the irradiation test loop include:

[0009] Determine the structural features and volumes of the circuit irradiation device, leak detection system and supporting pipelines in the irradiation test circuit;

[0010] Determine the system composition and connection method of the loop irradiation device, leak detection system and supporting pipelines, and build the second model;

[0011] Determine the main equipment, main components and main pipelines in the irradiation test circuit;

[0012] The second model is simplified according to main equipment, main components and main pipelines to obtain the first model.

[0013] In a feasible implementation manner, the steps of simplifying the second model according to the main equipment, main components and main pipelines to obtain the first model include:

[0014] Make the second model consistent with the structure of the circuit irradiation device, and make the connection relationship between the main components consistent with the connection relationship between the actual structure of the irradiation test circuit;

[0015] Simplify the off-core piping part of the main loop so that the coolant volume of the off-core piping part in the second model is the same as the coolant volume in the actual pipeline of the irradiation test loop;

[0016] Simplify other auxiliary systems and components;

[0017] The part of the extra-pile leak detection system is simplified so that the medium volume of the extra-pile leak detection system in the second model is the same as the medium volume in the actual extra-pile leak detection system of the irradiation test loop.

[0018] In a feasible implementation, the overpressure protection device is arranged on the leak detection system of the radiation test circuit, and the overpressure protection device is used to discharge the gas in the leak detection system.

[0019] In a feasible implementation manner, the step of determining the initial boundary conditions of the overpressure protection device includes:

[0020] Determine the volume of the external spraying space of the overpressure protection device and the type of medium to be sprayed externally;

[0021] Determine the initial pressure and initial temperature of the external blowdown space of the overpressure protection device.

[0022] In a feasible implementation manner, the step of selecting an initiating event that causes overpressure protection includes:

[0023] Determine the likely location of the initiating event;

[0024] Determine the possible occurrence of the initiating event;

[0025] The location and accident with the most serious consequences are selected as the initiating events that trigger overpressure protection.

[0026] In a feasible implementation manner, the step of calculating the spray cross-sectional area of ​​the overpressure protection device includes:

[0027] Selecting the cross-sectional area of ​​the smallest diameter pipe in the leak detection system as the spray cross-sectional area of ​​the overpressure protection device for analysis and calculation to obtain a first calculation result;

[0028] When the first calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, the spraying cross-sectional area of ​​the overpressure protection device is increased and iterative calculation is performed;

[0029] Until the spraying cross-sectional area meets the pressure-bearing requirements of the material used for the overpressure protection device, the cross-sectional area that meets the pressure-bearing requirements of the material used for the overpressure protection device is selected as the spraying cross-sectional area of ​​the overpressure protection device.

[0030] In a feasible implementation manner, the steps of calculating the delayed start time of the overpressure protection device include:

[0031] Selecting the first delayed start time as the spraying delayed start time of the overpressure protection device for analysis and calculation to obtain a second calculation result;

[0032] When the second calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, reducing the first delayed start time and performing iterative calculation;

[0033] Until the delayed start time of spraying meets the pressure-bearing requirements of the materials used for the overpressure protection device, the delayed start time that meets the pressure-bearing requirements of the materials used for the overpressure protection device is selected as the delayed start time of spraying of the overpressure protection device.

[0034] In a feasible implementation manner, after calculating the spraying cross-sectional area of ​​the overpressure protection device and calculating the spraying delay start time of the overpressure protection device, the method further includes:

[0035] Coupling optimization of spray cross-sectional area and spray delay start time.

[0036] In a feasible implementation manner, the steps of coupling optimization of the spray cross-sectional area and the spray delay start time include:

[0037] Determine the initial spraying cross-sectional area size and the initial spraying delay start time of the overpressure protection device, perform calculations, and obtain a third calculation result;

[0038] When the third calculation result does not meet the pressure-bearing requirements of the material used for the overpressure protection device, the size of the initial spraying cross-sectional area is kept unchanged, the spraying delay start time of the overpressure protection is adjusted, and the analysis and calculation are performed to obtain the fourth calculation result;

[0039] When the fourth calculation result does not meet the pressure-bearing requirements of the materials used for the overpressure protection device, the initial spray delay start time is kept unchanged, the spray cross-sectional area size of the overpressure protection device is adjusted, and the analysis and calculation are performed;

[0040] Repeat the above calculation steps until the obtained spray cross-sectional area and spray delay start time meet the pressure requirements of the materials used in the overpressure protection device.

[0041] Compared with the prior art, the present invention provides a method for designing an overpressure protection circuit for an irradiation test. The beneficial effects are as follows:

[0042] The embodiment of the present application provides an overpressure protection design method for an irradiation test circuit. By constructing a first model of the irradiation test circuit, it is assumed that the initial conditions causing overpressure protection and the boundary conditions of the overpressure protection device are assumed. When the leak detection system is overpressured, the pressure of the leak detection system is made not to exceed the pressure limit of the insulation pipe by adjusting the cross-sectional area of ​​the overpressure protection device and the spraying start time, thereby obtaining a spraying cross-sectional area size and a spraying delay start time of the overpressure protection device. According to the calculated spraying cross-sectional area size and the spraying delay start time, a suitable overpressure protection device is selected to relieve the pressure of the irradiation test circuit in time to prevent the pressure of the leak detection system from exceeding the pressure limit of the insulation pipe, thereby ensuring the safety and reliability of the operation of the irradiation test circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0044] Figure 1 A schematic flowchart of the steps of an overpressure protection design method for an irradiation test circuit provided in an embodiment of the present application;

[0045] Figure 2 A schematic diagram of the installation position of an overpressure protection device in an overpressure protection design method for an irradiation test circuit provided in an embodiment of the present application;

[0046] Figure 3 A schematic flowchart of the steps for constructing a first model of an irradiation test circuit in a method for designing an overpressure protection for an irradiation test circuit according to an embodiment of the present application;

[0047] Figure 4 A schematic diagram of a first model constructed in a radiation test circuit overpressure protection design method according to an embodiment of the present application;

[0048] Figure 5 A schematic flowchart of steps for determining the initial boundary conditions of an overpressure protection device in an irradiation test circuit overpressure protection design method according to an embodiment of the present application;

[0049] Figure 6 A schematic flowchart of steps for selecting an initiating event causing overpressure protection in an irradiation test circuit overpressure protection design method provided in an embodiment of the present application;

[0050] Figure 7 A schematic flowchart of the steps for calculating the spray cross-sectional area of ​​an overpressure protection device in an irradiation test circuit overpressure protection design method provided in an embodiment of the present application;

[0051] Figure 8 A schematic flowchart of the steps for calculating the delayed start time of the overpressure protection device in the overpressure protection design method for the irradiation test circuit provided in an embodiment of the present application;

[0052] Fig. 9 A schematic flowchart of the steps of an overpressure protection design method for an irradiation test circuit according to another embodiment of the present application;

[0053] Fig.10 A schematic flowchart of steps for coupling optimization of the spray cross-sectional area and the spray delay start time in an irradiation test circuit overpressure protection design method according to an embodiment of the present application;

[0054] in, Figures 1 to 10 The corresponding relationship between the reference numerals and component names in the figure is:

[0055] 001, regulating valve; 010, first overpressure protection device connection; 011, second overpressure protection device connection;

[0056] 100, descending section; 101, lower joint; 102, ascending section; 103, outlet section; 104, loop main pump; 105, main pump outlet section; 106, device inlet section; 107, annular air gap; 109, first leak detection system pipeline; 110, second leak detection system pipeline;

[0057] 111. The third leak detection system pipeline; 112. The leak detection system outlet; 113. The leak detection system safety valve; 114. The safe discharge space; 115. The first overpressure protection device; 116. The first blow-off outlet; 117. The second overpressure protection device; 118. The second blow-off outlet. DETAILED DESCRIPTION

[0058] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0060] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0061] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application.

[0062] like Figure 1 As shown, according to an embodiment of the present application, a radiation test circuit overpressure protection design method is proposed, including:

[0063] Step 100: construct a first model of the irradiation test circuit and determine the installation position of the overpressure protection device;

[0064] Step 200: Determine the initial boundary conditions of the overpressure protection device;

[0065] Step 300: Selecting an initiating event that causes overpressure protection;

[0066] Step 400: Calculate the spray cross-sectional area of ​​the overpressure protection device;

[0067] Step 500: Calculate the spray delay start time of the overpressure protection device.

[0068] The embodiment of the present application provides an overpressure protection design method for an irradiation test circuit. By constructing a first model of the irradiation test circuit, it is assumed that the initial conditions causing overpressure protection and the boundary conditions of the overpressure protection device are assumed. When the leak detection system is overpressured, the pressure of the leak detection system is made not to exceed the pressure limit of the insulation pipe by adjusting the cross-sectional area of ​​the overpressure protection device and the spraying start time, thereby obtaining a spraying cross-sectional area size and a spraying delay start time of the overpressure protection device. According to the calculated spraying cross-sectional area size and the spraying delay start time, a suitable overpressure protection device is selected to relieve the pressure of the irradiation test circuit in time to prevent the pressure of the leak detection system from exceeding the pressure limit of the insulation pipe, thereby ensuring the safety and reliability of the operation of the irradiation test circuit.

[0069] Furthermore, before constructing the first model of the irradiation test circuit, the objects to be analyzed should be clearly defined, and then the connection relationship between the objects to be analyzed should be clarified.

[0070] In some examples, such as Figure 2 As shown, the objects to be analyzed include but are not limited to the irradiation device and its supporting off-pile circuit, the leak detection system and its supporting pipeline valves. The irradiation device is connected to the supporting off-pile circuit through pipelines and flanges. The irradiation device includes: a pressure pipe, an annular air gap and an insulating pipe arranged in sequence from the inside to the outside. The annular air gap is connected to the leak detection system through a pipeline at the upper part of the insulating pipe, so that the leak detection system can detect leaks in the annular air gap.

[0071] like Figure 3 As shown, in a feasible implementation manner, the steps of constructing a first model of the irradiation test loop include:

[0072] Step 101: Determine the structural characteristics and volume of the circuit irradiation device, the leak detection system and the supporting pipelines in the irradiation test circuit;

[0073] Step 102: Determine the system composition and connection method of the loop irradiation device, the leak detection system and the supporting pipelines, and construct a second model;

[0074] Step 103: Determine the main equipment, main components and main pipelines in the irradiation test circuit;

[0075] Step 104: Simplify the second model according to the main equipment, main components and main pipelines to obtain the first model.

[0076] In this technical solution, a method for constructing a model of an irradiation test loop is further provided. First, a complete second model is constructed based on the structural characteristics and volumes of the loop irradiation device, leak detection system and supporting pipelines in the irradiation test loop, as well as the system composition and connection methods of the loop irradiation device, leak detection system and supporting pipelines. Then, the second model is simplified based on the main equipment, main components and main pipelines in the irradiation test loop to complete the construction of the first model of the irradiation test loop.

[0077] In a feasible implementation manner, the steps of simplifying the second model according to the main equipment, main components and main pipelines to obtain the first model include:

[0078] Make the second model consistent with the structure of the circuit irradiation device, and make the connection relationship between the main components consistent with the connection relationship between the actual structure of the irradiation test circuit;

[0079] Simplify the off-core piping part of the main loop so that the coolant volume of the off-core piping part in the second model is the same as the coolant volume in the actual pipeline of the irradiation test loop;

[0080] Simplify other auxiliary systems and components;

[0081] The part of the extra-pile leak detection system is simplified so that the medium volume of the extra-pile leak detection system in the second model is the same as the medium volume in the actual extra-pile leak detection system of the irradiation test loop.

[0082] In this technical solution, a method for simplifying the second model of the irradiation test loop to obtain the first model is further provided, so that the second model has the same structure as the actual irradiation test loop, and the off-core piping part of the main loop and the off-core piping part of the leak detection system are simplified, and only the coolant volume of the off-core piping part in the second model is ensured to be the same as the coolant volume in the actual system pipeline, and the medium volume of the off-core leak detection system in the second model is ensured to be the same as the medium volume in the actual off-core leak detection system, so as to obtain the first model of the irradiation test loop.

[0083] In some examples, such as Figure 4The irradiation test circuit includes an irradiation device, a main circuit of the irradiation device, an off-pile circuit of the irradiation device, a leak detection system, a first overpressure protection device 115 , a second overpressure protection device 117 , a first blowdown outlet 116 , and a second blowdown outlet 118 . The main circuit of the irradiation device includes a descending section 100, a lower joint 101, and an ascending section 102; the extra-pile circuit of the irradiation device includes an outlet section 103, a circuit main pump 104, a main pump outlet section 105, and a device inlet section 106; the leak detection system includes an annular air gap 107, a first leak detection system pipeline 109, a second leak detection system pipeline 110, and a third leak detection system pipeline 111. A regulating valve is provided on the pressure pipe between the annular air gap and the descending section to simulate a breach on the pressure pipe through the regulating valve 001, so that the coolant in the main circuit of the irradiation device can enter the leak detection system through the breach, and different breach sizes are simulated by changing the cross-sectional area of ​​the regulating valve 001, and the axial position of the breach on the pressure pipe is simulated by changing the position of the regulating valve 001 on the pressure pipe.

[0084] As a preferred solution, the coolant parameters select the maximum temperature and maximum pressure of the circuit design, and the nitrogen parameters select the pressure and temperature of the normal operation of the nitrogen leak detection system.

[0085] like Figure 4 As shown, in a feasible implementation manner, the overpressure protection device is arranged on the leak detection system of the radiation test circuit, and the overpressure protection device is used to discharge the gas in the leak detection system.

[0086] In this technical solution, an installation position of the overpressure protection device in the overpressure protection box system is provided. The overpressure protection device is installed on the leak detection system. When an overpressure accident occurs, excess gas in the leak detection system is quickly and effectively discharged to avoid damage to the insulation tube and impact of high-pressure gas on the research reactor core, thereby improving the operating safety and reliability of the irradiation device and the reactor.

[0087] In some examples, the leak detection system monitors the pressure of the air gap between the irradiation device pressure pipe (high pressure side) and the irradiation device insulation pipe (low pressure side) in the irradiation test circuit, the discharge outlet of the overpressure protection device is the external environment, and the overpressure protection device is connected to the annular gap of the leak detection system to relieve the pressure on the leak detection system.

[0088] As a preferred solution, the overpressure protection device is installed in the position that can best ensure the safety of the irradiation device. Figure 2 Three preferred locations for installing the overpressure protection device are shown. It should be noted that the location where the overpressure protection device can best protect the safety of the irradiation device is the location where the maximum pressure of the leak detection system does not exceed the pressure limit of the insulation pipe under accident conditions; the location where the overpressure protection device can best protect the safety of the irradiation device is the location where the leak detection system can respond quickly under accident conditions.

[0089] Furthermore, the leak detection system is a gas system, which generally consists of two leak detection pumps, matching pipes and valves, and an air gap between the pressure pipe and the insulation pipe. During normal operation, the two leak detection pumps fill nitrogen into the leak detection system pipeline, including the annular air gap between the pressure pipe and the insulation pipe, and continuously circulate the nitrogen in the leak detection system. Instruments are used to monitor the temperature, pressure, and humidity of the nitrogen to monitor whether the irradiation device has any abnormalities. When the pressure pipe ruptures and leaks, the coolant in the loop will leak into the leak detection system from the rupture, and the pressure, temperature, and humidity in the leak detection system will change. By designing a pressure-maintaining protection device on the leak detection system to relieve the pressure of the leak detection system, the safety of the irradiation device and the reactor can be ensured.

[0090] like Figure 5 As shown, in a feasible implementation manner, the step of determining the initial boundary conditions of the overpressure protection device includes:

[0091] Step 201: Determine the volume of the external spraying space of the overpressure protection device and the type of the externally sprayed medium;

[0092] Step 202: Determine the initial pressure and initial temperature of the external blowdown space of the overpressure protection device.

[0093] In this technical solution, specific contents for determining the initial boundary conditions of the overpressure protection device are further provided. After determining the volume and medium of the blowout outlet of the overpressure protection device, the initial pressure and initial temperature of the space outside the blowout outlet are determined, which is beneficial to improving the accuracy of subsequent calculation of the delayed start time of the blowout of the overpressure protection device.

[0094] As a preferred embodiment, the boundary conditions are room temperature and standard atmospheric pressure.

[0095] like Figure 6 As shown, in a feasible implementation manner, the step of selecting an initiating event causing overpressure protection includes:

[0096] Step 301: Determine the possible location of the initiating event;

[0097] Step 302: Determine the possible occurrence of the initiating event;

[0098] The location and accident with the most serious consequences are selected as the initiating events that trigger overpressure protection.

[0099] In this technical solution, based on the initial boundary conditions, conservative assumptions are made by selecting the accidents with the most serious consequences and their locations, to ensure that the irradiation test circuit can meet the safety requirements under other accident conditions.

[0100] Furthermore, the most serious accident location and the time of the accident are determined based on the pressure response of the leak detection system after the accident. The higher the pressure of the leak detection system, the more serious the accident and the greater the impact on the irradiation test circuit; the shorter the time it takes for the leak detection system pressure response to reach the maximum value, the more serious the accident and the greater the impact on the irradiation test circuit. According to this principle, Figure 4 , analyze and screen the accidents occurring at the bottom, middle and upper parts of the pressure pipe. Similarly, analyze the small, medium and large rupture accidents occurring at the pressure pipe and screen out the accidents with the most serious consequences.

[0101] like Figure 7 As shown, in a feasible implementation manner, the step of calculating the spray cross-sectional area of ​​the overpressure protection device includes:

[0102] Step 401: Select the cross-sectional area of ​​the smallest diameter pipe in the leak detection system as the spray cross-sectional area of ​​the overpressure protection device for analysis and calculation to obtain a first calculation result;

[0103] Step 402: when the first calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, increase the spraying cross-sectional area of ​​the overpressure protection device and perform iterative calculation;

[0104] Step 403: until the spraying cross-sectional area meets the pressure-bearing requirement of the material used for the overpressure protection device, select the cross-sectional area that meets the pressure-bearing requirement of the material used for the overpressure protection device as the spraying cross-sectional area of ​​the overpressure protection device.

[0105] In this technical solution, specific contents for determining the spraying cross-sectional area of ​​the overpressure protection device are further provided. The smallest pipe cross-sectional area in the first model is first analyzed as the initial cross-sectional area of ​​the overpressure protection device, and the maximum pressure value of the leak detection system is calculated. If the maximum pressure value exceeds the pressure limit of the insulation pipe, the spraying cross-sectional area of ​​the overpressure protection device is increased for the next iteration. The cross-sectional area of ​​the spraying section of the overpressure protection device is adjusted through iterative calculation, and then the spraying efficiency of the overpressure protection device is changed to control the pressure in the insulation pipe not to exceed the pressure requirement of the insulation pipe, thereby meeting the safety requirements of the irradiation test circuit.

[0106] Furthermore, when the iterative calculation result meets the pressure requirement of the insulation pipe or the spraying cross-sectional area reaches the equivalent diameter of the insulation pipe, the iteration is stopped.

[0107] It is understandable that the cross-sectional area of ​​the overpressure protection device should be smaller than the maximum size of the overpressure protection device that can be installed on the insulation pipe.

[0108] like Figure 8 As shown, in a feasible implementation manner, the steps of calculating the spray delay start time of the overpressure protection device include:

[0109] Step 501: Selecting a first delayed start time as a spraying delayed start time of an overpressure protection device for analysis and calculation to obtain a second calculation result;

[0110] Step 502: when the second calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, reduce the first delayed start time and perform iterative calculation;

[0111] Step 503: until the delayed start time of the spraying meets the pressure requirement of the material used for the overpressure protection device, the delayed start time that meets the pressure requirement of the material used for the overpressure protection device is selected as the delayed start time of the spraying of the overpressure protection device.

[0112] In this technical solution, specific contents for determining the delayed start time of the spraying of the overpressure protection device are further provided. The analysis starts with the first delayed start time as the initial delay time of the overpressure protection device, and the maximum pressure value of the leak detection system is calculated. If the maximum pressure value exceeds the pressure limit of the insulation pipe, the delayed start time of the spraying is reduced for the next iteration. The start delay time of the overpressure protection device is adjusted through iterative calculation, thereby changing the response pressure of the overpressure protection device in an accident situation and improving the reliability of the detection results of the leak detection system.

[0113] As a preferred solution, considering the delay performance of the overpressure protection device, the first delayed start time is 100ms. The analysis starts with 100ms as the initial delay time of the overpressure protection device, and the maximum pressure value of the leak detection system is calculated. When analyzing the accident conditions, ensure that the maximum pressure of the leak detection system under different delay conditions meets the pressure bearing capacity requirements of the system.

[0114] Furthermore, when the iterative calculation result satisfies the pressure requirement of the insulation pipe or the minimum response time of the overpressure protection device, the iteration is stopped.

[0115] It is understandable that the spray delay start time should be greater than the fastest start time of the overpressure protection device.

[0116] like Fig. 9 As shown, in a feasible implementation manner, after calculating the spraying cross-sectional area of ​​the overpressure protection device and calculating the spraying delay start time of the overpressure protection device, the following steps are then included:

[0117] Step 600: Coupling and optimizing the spray cross-sectional area and the spray delay start time.

[0118] In this technical solution, by coupling and optimizing the spray cross-sectional area and the spray delay start time, the overpressure protection setting can maximize the pressure relief efficiency of the overpressure protection device on the leak detection system without affecting the reliability of the original detection results of the leak detection system, so that the leak detection system can relieve pressure at the fastest speed.

[0119] like Fig.10As shown, in a feasible implementation manner, the steps of coupling optimization of the spray cross-sectional area and the spray delay start time include:

[0120] Step 601: determining the initial spraying cross-sectional area size and the initial spraying delay start time of the overpressure protection device, performing calculations, and obtaining a third calculation result;

[0121] Step 602: When the third calculation result does not meet the pressure bearing requirement of the material used for the overpressure protection device, the size of the initial spraying cross-sectional area is kept unchanged, the spraying delay start time of the overpressure protection is adjusted, and analysis and calculation are performed to obtain a fourth calculation result;

[0122] Step 603: when the fourth calculation result does not meet the pressure bearing requirement of the material used for the overpressure protection device, the initial spraying delay start time is kept unchanged, the spraying cross-sectional area size of the overpressure protection device is adjusted, and analysis and calculation are performed;

[0123] Step 604: Repeat the above calculation steps until the obtained spray cross-sectional area and spray delay start time both meet the pressure requirements of the materials used in the overpressure protection device.

[0124] In this technical solution, the specific contents of the coupled optimization of the spraying cross-sectional area and the spraying delayed start time are further given, and the spraying cross-sectional area size and the spraying delayed start time of the potential overpressure protection device are coupled for analysis. First, a spraying cross-sectional area that meets the requirements is selected as the initial value, and the maximum pressure reached by the leak detection system in an accident under different delay time conditions is analyzed; then a spraying delay start time that meets the requirements is selected as the initial value, and the maximum pressure reached by the leak detection system in an accident under different spraying cross-sectional conditions is analyzed. A comprehensive analysis is conducted on all combinations of spraying cross-sectional area sizes and spraying delay times that meet the conditions, and the one with the most ideal pressure relief effect on the leak detection system is selected.

[0125] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0126] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A method for designing overpressure protection of an irradiation test circuit, characterized in that: The radiation test circuit overpressure protection design method includes: Construct the first model of the irradiation test circuit and determine the installation location of the overpressure protection device; Determine the initial boundary conditions of the overpressure protection device and select the initiating event that causes the overpressure protection; The spraying cross-sectional area of ​​the overpressure protection device is calculated, and the spraying delay start time of the overpressure protection device is calculated.

2. The method for designing overpressure protection of an irradiation test circuit according to claim 1, characterized in that: The step of constructing the first model of the radiation test loop includes: Determine the structural features and volumes of the circuit irradiation device, leak detection system and supporting pipelines in the irradiation test circuit; Determine the system composition and connection method of the loop irradiation device, the leak detection system and the supporting pipelines, and construct the second model; Determine the main equipment, main components and main pipelines in the irradiation test circuit; The second model is simplified according to the main equipment, the main components and the main pipelines to obtain the first model.

3. The method for designing overpressure protection of an irradiation test circuit according to claim 2, characterized in that: The step of simplifying the second model according to the main equipment, the main components and the main pipelines to obtain the first model comprises: Make the second model consistent with the structure of the circuit irradiation device, and make the connection relationship between the main components consistent with the connection relationship between the actual structure of the irradiation test circuit; Simplifying the off-core piping portion of the main loop so that the coolant volume of the off-core piping portion in the second model is the same as the coolant volume in the actual pipeline of the irradiation test loop; Simplify other auxiliary systems and components; The ex-pile leak detection system part is simplified so that the medium volume of the ex-pile leak detection system in the second model is the same as the medium volume in the actual ex-pile leak detection system of the irradiation test loop.

4. The method for designing overpressure protection of an irradiation test circuit according to claim 1, characterized in that: The overpressure protection device is arranged on the leak detection system of the radiation test circuit, and the overpressure protection device is used to discharge the gas in the leak detection system.

5. The method for designing overpressure protection of an irradiation test circuit according to claim 1, characterized in that: The step of determining the initial boundary conditions of the overpressure protection device comprises: Determine the volume of the external spraying space of the overpressure protection device and the type of the externally sprayed medium; Determine the initial pressure and initial temperature of the external blowdown space of the overpressure protection device.

6. The method for designing overpressure protection of an irradiation test circuit according to claim 1, characterized in that: The step of selecting an initiating event causing overpressure protection comprises: Determine the likely location of the initiating event; Determine the likely occurrence of the initiating event(s); The occurrence location and the accident with the most serious consequences are selected as the initiating event causing the overpressure protection.

7. The method for designing overpressure protection of an irradiation test circuit according to claim 1, characterized in that: The step of calculating the spraying cross-sectional area of ​​the overpressure protection device comprises: Selecting the cross-sectional area of ​​the smallest diameter pipe in the leak detection system as the spray cross-sectional area of ​​the overpressure protection device for analysis and calculation to obtain a first calculation result; When the first calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, increasing the spraying cross-sectional area of ​​the overpressure protection device and performing iterative calculation; Until the spraying cross-sectional area meets the pressure-bearing requirements of the material used for the overpressure protection device, the cross-sectional area that meets the pressure-bearing requirements of the material used for the overpressure protection device is selected as the spraying cross-sectional area of ​​the overpressure protection device.

8. The method for designing overpressure protection of an irradiation test circuit according to claim 1, characterized in that: The step of calculating the delayed start time of the overpressure protection device comprises: Selecting the first delayed start time as the delayed start time of the overpressure protection device for analysis and calculation to obtain a second calculation result; When the second calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, reducing the first delayed start time and performing iterative calculation; Until the delayed start time of the spraying meets the pressure-bearing requirements of the materials used for the overpressure protection device, the delayed start time that meets the pressure-bearing requirements of the materials used for the overpressure protection device is selected as the delayed start time of the spraying of the overpressure protection device.

9. The method for designing overpressure protection of an irradiation test circuit according to claim 1, characterized in that: After calculating the spraying cross-sectional area of ​​the overpressure protection device and calculating the spraying delay start time of the overpressure protection device, the method further comprises: The spray cross-sectional area and the spray delay start time are coupled and optimized.

10. The method for designing overpressure protection of an irradiation test circuit according to claim 9, characterized in that: The step of coupling and optimizing the spray cross-sectional area and the spray delay start time comprises: Determine the initial spraying cross-sectional area size and the initial spraying delay start time of the overpressure protection device, perform calculations, and obtain a third calculation result; When the third calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, the size of the initial spraying cross-sectional area is kept unchanged, the spraying delay start time of the overpressure protection is adjusted, and the analysis and calculation are performed to obtain a fourth calculation result; When the fourth calculation result does not meet the pressure-bearing requirement of the material used for the overpressure protection device, the initial spray delay start time is kept unchanged, the spray cross-sectional area size of the overpressure protection device is adjusted, and the analysis and calculation are performed; The above calculation steps are repeated until the obtained spray cross-sectional area and the spray delay start time both meet the pressure-bearing requirements of the materials used for the overpressure protection device.

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