Method and system for determining protection signal of heat pipe micro-stack
By determining the safety standards and accident analysis model of heat pipe micro-releases and optimizing the protection signal list, the problem of determining protection signals of heat pipe micro-releases is solved, and the safety and accident monitoring accuracy of nuclear power plants are improved.
Patent Information
- Application Number
- CN202311503645.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-13
- Publication Date
- 2025-01-14
AI Technical Summary
The prior art lacks systematic methods to effectively determine the protection signals of heat pipe micro-releases, resulting in risks in safe operation and accident monitoring of nuclear power plants.
By obtaining safety guidelines for heat pipe micro-releases, a list of potential protection signals is determined, and combined with accident analysis models and design constraints, implementability optimization and critical accident verification are carried out to form a final protection signal list.
The comprehensive and rapid determination of heat pipe micro-release protection signals is achieved, ensuring safe operation and accident mitigation, and improving the safety and accuracy of nuclear power plants.
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Figure CN119311682A_ABST
Abstract
Description
Technical Field
[0001] The present invention mainly relates to a nuclear micro-reactor safety design, and in particular to a method and system for determining a protection signal of a heat pipe micro-reactor. Background Art
[0002] In nuclear power plants, protection signals are physical parameters used for operating status monitoring and accident condition monitoring, which activate the protection system when the change exceeds the safety setting value. In the research and development stage of new reactor types, protection signals are the prerequisite for scheme design and safety analysis. Therefore, the comprehensiveness and effectiveness of the protection signal list are crucial to the safe operation of nuclear power plants.
[0003] Heat pipe micro-reactors refer to solid-state micro-reactors in which the primary loop system of a micro-reactor does not adopt a coolant loop arrangement, but uses heat pipes to transfer the heat generated by the core to the secondary loop system or the thermoelectric conversion system. Compared with traditional pressurized water reactors, high-temperature gas-cooled reactors and other micro-reactor models, heat pipe micro-reactors have the following differences: 1) The equipment is very different, no main pump is required, and the main equipment includes fuel rods, matrix, high-temperature heat pipes, shielding, drive mechanism, dedicated exhaust system and thermodynamic conversion module, etc.; 2) The heat transfer path is very different. The fuel rod conducts heat to the matrix, and then conducts heat to the evaporation end of the high-temperature heat pipe. The heat is transferred to the condensation section of the heat pipe through the evaporation and condensation process of the working fluid inside the heat pipe, and then the heat is transferred to the hot end of the thermoelectric conversion device / secondary loop system through natural circulation. After the thermoelectric conversion device / secondary loop system converts thermal energy into electrical energy, the remaining waste heat is discharged to the final heat sink (atmosphere or environment) through the heat exchanger.
[0004] Due to the differences in the above equipment and heat transfer paths, the heat pipe micro-reactor produces new key phenomena and characteristics, resulting in a unique list of heat pipe micro-reactor protection signals, which is very different from existing reactor types. At present, there is no systematic and effective method for determining the heat pipe micro-reactor protection signals at home and abroad. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a method and system for determining a protection signal of a heat pipe micro-stack, which can comprehensively and quickly determine the protection signal of the heat pipe micro-stack.
[0006] To solve the above technical problems, the present invention provides a method for determining a protection signal of a heat pipe micro-reactor, comprising the following steps: obtaining safety criteria of a heat pipe micro-reactor, wherein each safety criterion involves at least one protection signal; determining a first potential protection signal list according to the safety criteria, the first potential protection signal list including at least one potential protection signal; obtaining a heat pipe micro-reactor accident list, the heat pipe micro-reactor accident list including at least one accident category, each accident category including one or more accidents; determining a second potential protection signal list according to the heat pipe micro-reactor accident list, the second potential protection signal list including at least one potential protection signal; optimizing the feasibility of the first potential protection signal list and the second potential protection signal list according to statutory protection signal requirements and design constraints to determine a preliminary protection signal list; and performing key accident verification on the protection signals in the preliminary protection signal list to determine the protection signal setting values that meet the safety criteria, thereby obtaining a final protection signal list.
[0007] In one embodiment of the present application, the step of obtaining the safety criteria of the heat pipe micro-rake includes: extracting the basic safety content related to reactivity control, residual heat removal and radioactive containment in the safety regulations of nuclear power plants; decomposing the basic safety content into multiple safety items; and determining the safety criteria of the heat pipe micro-rake based on the multiple safety items and the design features of the heat pipe micro-rake.
[0008] In one embodiment of the present application, the step of determining the safety criteria of the heat pipe micro-stack based on the multiple safety items and the design features of the heat pipe micro-stack includes: establishing a design feature network of the heat pipe micro-stack; screening relevant design features in the design feature network that are related to specific safety items in the multiple safety items; and determining the safety criteria of the relevant design features based on the specific safety item.
[0009] In one embodiment of the present application, the design feature network includes multiple layers of nodes, wherein the first layer of nodes includes a micro-rack system node and a thermoelectric conversion system node, the second layer of nodes includes a core node, a heat pipe node, a main heat exchanger node, a residual heat exchanger node and a stack node connected to the micro-rack system node, and a regenerator node, a turbine node, a compressor node and a motor node connected to the thermoelectric conversion system node, and the third layer of nodes includes a fuel rod node, a matrix node, a reflector node, a drum node and a safety rod node connected to the core node, and each node is a design feature.
[0010] In one embodiment of the present application, the step of determining the first potential protection signal list according to the security criteria includes: extracting keywords in each security criterion to obtain corresponding potential protection signals; and merging the potential protection signals corresponding to each security criterion into the first potential protection signal list.
[0011] In one embodiment of the present application, the step of determining a second potential protection signal list based on the heat pipe micro-reactor accident list includes: establishing an accident analysis model; for a specific accident category, using the accident analysis model to analyze the thermal-hydraulic response and potential mitigation paths after the accident; and forming potential protection signals based on the analysis results to form the second potential protection signal list.
[0012] In one embodiment of the present application, the step of optimizing the feasibility of the first potential protection signal list and the second potential protection signal list according to the statutory protection signal requirements and design constraints includes: for any potential protection signal in the first potential protection signal list and the second potential protection signal list, determining whether there is a matching preliminary protection signal for any potential protection signal; if so, placing the preliminary protection signal in the preliminary protection signal list; if not, determining whether there is an alternative preliminary protection signal for any potential protection signal; if so, placing the preliminary protection signal in the preliminary protection signal list, wherein the preliminary protection signal is a protection signal that can be implemented according to the design constraints.
[0013] In one embodiment of the present application, the step of performing critical accident verification on the preliminary protection signal in the preliminary protection signal list to determine the protection signal setting value that meets the safety criterion includes: establishing an accident analysis model; adding the preliminary protection signal to the accident analysis model and assigning an initial value; and using the accident analysis model to analyze the critical accident, and iteratively optimizing the preliminary protection signal based on the analysis result to obtain the protection signal setting value that can alleviate the critical accident as the final protection signal.
[0014] In an embodiment of the present application, the potential protection signal is a shutdown protection signal or a dedicated driving signal.
[0015] In one embodiment of the present application, the accident categories include increased heat output of the heat pipe micro-reactor system, reduced heat removal capacity of the thermoelectric conversion system, abnormal reactivity and power distribution, decreased matrix / heat pipe heat exchange capacity, and expected transients that fail to shut down the reactor urgently.
[0016] The present application also proposes a system for determining a protection signal of a heat pipe micro-stack, comprising a memory and a processor. The memory is used to store instructions executable by the processor. The processor is used to execute the instructions to implement any of the above methods.
[0017] The present application also proposes a computer storage medium storing a computer program code, wherein the computer program code implements the method as described above when executed by a processor.
[0018] Compared with the prior art, the system and method of the present invention form potential protection signal requirements from the basic safety content and the accident list, and iterate according to the regulatory requirements and specific implementation conditions to determine the preliminary protection signal list, and then verify the key accidents and iterate and optimize, and finally determine the protection signal list for comprehensive accident mitigation. The present invention is effective and simple to operate with high accuracy, and can be widely used in heat pipe micro-reactor design and accident safety evaluation. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present invention. In the accompanying drawings:
[0020] Figure 1 It is a cross-sectional view of a micro-stack system in a heat pipe micro-stack according to an embodiment of the present application.
[0021] Figure 2 It is a cross-sectional view of a thermoelectric conversion system in a heat pipe micro-stack according to an embodiment of the present application.
[0022] Figure 3 is a flow chart of a method for determining a protection signal according to an embodiment of the present application.
[0023] Figure 4 It is a flow chart of a method for obtaining safety criteria of a heat pipe micro-stack according to an embodiment of the present application.
[0024] Figure 5 It is a flow chart of a method for determining safety criteria of a heat pipe micro-stack according to an embodiment of the present application.
[0025] Figure 6 It is a schematic diagram of a design feature network according to an embodiment of the present application.
[0026] Figure 7 It is a flow chart of a method for determining a second potential protection signal list based on a heat pipe micro-reactor accident list according to an embodiment of the present application.
[0027] Figure 8 It is a flow chart of a method for performing critical accident verification on preliminary protection signals in a preliminary protection signal list to determine protection signal setting values that meet safety criteria according to an embodiment of the present application.
[0028] Fig. 9 4 is a system block diagram of determining a protection signal according to an embodiment of the present application. DETAILED DESCRIPTION
[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.
[0030] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.
[0031] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.
[0032] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.
[0033] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.
[0034] It should be understood that when a component is referred to as being "on another component," "connected to another component," "coupled to another component," or "contacting another component," it may be directly on, connected to, coupled to, or contacting the other component, or there may be intervening components. In contrast, when a component is referred to as being "directly on another component," "directly connected to," "directly coupled to," or "directly contacting" another component, there are no intervening components. Similarly, when a first component is referred to as being "electrically in contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between conductive components.
[0035] Figure 1 It is a cross-sectional view of a micro-stack system in a heat pipe micro-stack according to an embodiment of the present application. Figure 2 FIG. 1 is a cross-sectional view of a thermoelectric conversion system in a heat pipe micro-stack according to an embodiment of the present application. Figure 1 As shown, the micro-reactor system 10 of the present application includes a core 11, a heat pipe 12, a main heat exchanger 13, a residual heat exchanger (not shown) and a stack (not shown). The core 11 further includes a fuel rod 111, a substrate 112, a reflective layer 113, a drum 114 and a safety rod 115. The substrate 112 is cylindrical, and its cross-section can be rectangular, regular hexagonal or circular. A reflective layer 113 is arranged outside the substrate 112. The fuel rods 111 are distributed in the substrate 112 and are separated from each other. The drum 114 is inserted into the substrate 112 and can be rotated under the drive of the drum drive mechanism 114a to achieve the adjustment of the micro-reactor power. It can be movably inserted into the substrate 112, and can be inserted to different depths of the substrate 112 under the drive of the safety rod drive mechanism 115a to control the operation and stop of the micro-reactor. The heat pipe 12 is a core component responsible for heat transfer, connecting the core 11 and the main heat exchanger 13. The heat pipe 12 is located in the matrix 112 and is arranged between the fuel rods 111. Figure 2As shown, the thermoelectric conversion system 20 includes a regenerator 21, a gas turbine 22, a compressor 23, a motor 24, an air supply system 25 and an air outlet 26. The micro-reactor system 10 is mainly responsible for generating heat by micro-reactor fission and safely transferring the heat from the core 11 to the main heat exchanger 13. The thermoelectric conversion system 20 is responsible for converting the heat provided by the micro-reactor system 10 into electricity. The micro-reactor system 10 is connected to the thermoelectric conversion system 20 through an external pipeline.
[0036] In one embodiment, the size of the micro-stack system 10 and the thermoelectric conversion system 20 of the present application can be small enough to be placed on a container truck, forming a movable heat pipe micro-stack system.
[0037] The embodiment of the present application describes a method for systematically and effectively determining the protection signal of a heat pipe micro-reactor. Based on the overall design scheme, basic safety functions, and accident list of the heat pipe micro-reactor, combined with the feasibility of the system design, fuel material characteristics, instrumentation and control measurement scheme, etc., a protection signal for accident mitigation is determined, thereby monitoring the safe operation of the heat pipe micro-reactor core.
[0038] Figure 3 FIG. 1 is a flow chart of a method for determining a protection signal according to an embodiment of the present application. Figure 3 The method for determining the protection signal of the heat pipe micro-stack according to the present embodiment is described.
[0039] In step 301, safety criteria of the heat pipe micro-stack are obtained, wherein each safety criterion involves at least one protection signal.
[0040] In step 302, a first potential protection signal list is determined according to a safety criterion, wherein the first potential protection signal list includes at least one potential protection signal.
[0041] In step 303, a heat pipe micro-reactor accident list is obtained, where the heat pipe micro-reactor accident list includes at least one accident category, and each accident category includes one or more accidents.
[0042] In step 304, a second potential protection signal list is determined according to the heat pipe micro-reactor accident list, and the second potential protection signal list includes at least one potential protection signal.
[0043] In step 305, the feasibility of the first potential protection signal list and the second potential protection signal list is optimized according to the legal protection signal requirements and the design constraints to determine a preliminary protection signal list.
[0044] In step 306, critical accident verification is performed on the protection signals in the preliminary protection signal list to determine protection signal setting values that meet safety criteria, thereby obtaining a final protection signal list.
[0045] In the present application, the above method can be implemented using a computer in an assisted design manner, and one or more steps in the above method can be executed by a program.
[0046] In step 301, safety criteria may be obtained based on three basic safety functions in nuclear power plant safety regulations. Figure 4 FIG. 1 is a flow chart of a method for obtaining safety criteria for a heat pipe micro-stack according to an embodiment of the present application. Figure 4 The exemplary implementation details of step 301 are described as shown. In step 401, the basic safety content of reactivity control, residual heat removal and radioactive containment in the safety regulations of nuclear power plants is extracted. In this step, the basic safety content of reactivity control, residual heat removal and radioactive containment in the safety regulations of nuclear power plants can be extracted by a computer program, and the basic safety content input into the computer program by the user through the human-machine interface can also be received. In step 402, the basic safety content is decomposed into multiple safety items. In this step, the basic safety content can be identified by a natural language processing (NLP) model and decomposed into multiple safety items. For safety considerations, each safety item can be effective after being reviewed and confirmed by the user. In step 403, the safety criteria of the heat pipe micro-pile are determined based on multiple safety items and the design features of the heat pipe micro-pile. The design feature of the heat pipe micro-pile here is a node network composed of components of the heat pipe micro-pile, and the determination of the safety criteria needs to consider the design feature network represented by this node network.
[0047] Figure 5 FIG. 1 is a flow chart of a method for determining the safety criteria of a heat pipe micro-stack according to an embodiment of the present application. Figure 5 The exemplary implementation details of step 403 are shown in FIG. 5. In step 501, a design feature network of a heat pipe micro-stack is established. Figure 6As shown, the exemplary design feature network includes multiple layers of nodes, wherein the first layer of nodes includes micro-stack system nodes and thermoelectric conversion system nodes, the second layer of nodes includes core nodes, heat pipe nodes, main heat exchanger nodes, exhaust heat exchanger nodes and stack nodes connected to the micro-stack system nodes, and regenerator nodes, turbine nodes, compressor nodes and motor nodes connected to the thermoelectric conversion system nodes, and the third layer of nodes includes fuel rod nodes, matrix nodes, reflector nodes, drum nodes and safety rod nodes connected to the core nodes, and each node is a design feature. In step 502, the design feature network is screened for relevant design features related to a specific safety item in multiple safety items. In this step, the design feature network is screened for relevant design features for a specific safety item. For example, if a certain safety item involves a certain performance requirement of the core, the nodes related to the performance requirement are screened from each subnode of the core. In step 503, the safety criteria of the relevant design features are determined according to the specific safety item. After the relevant design features (i.e., the nodes in the previous text) are determined, the safety criteria of the relevant design features are determined according to the performance requirements of the specific safety item.
[0048] For example, for the safety item "Radioactive Containment of the Core", it can be seen from the analysis that in order to limit the release of radioactivity, it is necessary to ensure that all components of the core are intact. Figure 6 From the design feature network, we can see that the integrity of the fuel rods and the matrix must be ensured. Therefore, two safety criteria are obtained: using the highest cladding temperature to ensure the integrity of the fuel cladding (fuel cladding criterion); using the highest fuel temperature to ensure the integrity of the fuel pellets (fuel pellet criterion).
[0049] Following the above example, in step 302, the keywords "maximum cladding temperature" and "maximum fuel temperature" in each safety criterion, such as the fuel cladding criterion and the fuel pellet criterion, are extracted to obtain corresponding potential protection signals: fuel cladding temperature and fuel pellet temperature. The potential protection signals corresponding to each safety criterion are merged into a first potential protection signal list. In an embodiment of the present application, the potential protection signal may be a shutdown protection signal or a dedicated drive signal.
[0050] In step 303, a heat pipe micro-stack accident list input by a user may be obtained through a human-machine interface, or an external heat pipe micro-stack accident list may be received through a communication interface. An exemplary heat pipe micro-stack accident list is shown in Table 1 below.
[0051] Table 1 List of heat pipe micro-reactor accidents
[0052]
[0053] It can be understood that Table 1 only shows some categories and some accidents in the heat pipe micro-reactor accident list, and the heat pipe micro-reactor accident list of the present application may include more categories and more accidents.
[0054] Figure 7 1 is a flow chart of a method for determining a second potential protection signal list according to a heat pipe micro-reactor accident list according to an embodiment of the present application. Figure 7 The exemplary implementation details of step 304 are described as shown. In step 701, an accident analysis model is established. Specifically, a digital model is established based on the structure of the heat pipe micro-repile to simulate the cause of the accident, the evolution process of the accident, the accident phenomenon, the potential consequences of the accident and the potential mitigation path of the heat pipe micro-repile accident. In step 702, for a specific accident category (such as a category in Table 1), the accident analysis model is used to analyze the thermal-hydraulic response and potential mitigation path after the accident. Here, the thermal-hydraulic response characterizes the evolution process of the accident, the accident phenomenon, the potential consequences of the accident, etc. In step 703, a potential protection signal is formed according to the analysis results to form a second potential protection signal list. Here, the potential protection signal is a protection signal that ensures that the accident safety criteria do not exceed the limit value and the accident can be effectively mitigated.
[0055] For example, in the case of an increase in heat output accident in a heat pipe micro-reactor system, the accident analysis model shows that it will introduce positive reactivity, increase the core power, and the core heat cannot be effectively removed in time, the core heat transfer will deteriorate, and the fuel element-matrix-heat pipe temperature may exceed the specified limit, resulting in damage to the fuel element and matrix. In response to this accident, the reactor must be shut down as soon as possible and the residual heat removal system must be put into use to form a shutdown protection signal: high neutron flux positive change rate, fuel pellet temperature, fuel cladding temperature, etc.; and a dedicated drive signal: fuel pellet temperature signal, fuel cladding temperature, etc.
[0056] A similar analysis method is also used for other accident categories such as accidents involving reduced heat removal capacity of thermoelectric conversion systems to obtain corresponding potential protection signals, which will not be elaborated here.
[0057] In the aforementioned step 305, on the one hand, the protection signal is optimized according to the statutory protection signal requirements. For example, according to the "Research Reactor Design Safety Regulations" (HAF201) the design requirements for the protection system are: 1) The design of the protection system should implement the principle of diversity. If possible, each hypothetical initiating event should be detected by at least two different methods. The required protection action must be triggered automatically; 2) The protection system must have at least two sets of completely isolated and independent channels so that a single failure will not cause the loss of its function; 3) The design must ensure that there is a certain margin between the trigger point of the set value and the safety limit, that is, the action triggered by the protection system can play a role in controlling the process before reaching the safety limit. In addition, this margin must take into account the following factors: (1) instrument inaccuracy; (2) scale uncertainty; (3) instrument drift; (4) instrument and system response time. In order to increase safety, the margin can be increased. For example, according to the IAEA safety standard SSR-3, the design requirements for the protection system are: it must be ensured in the design that the set value can be determined, and its margin is between the starting value and the safety limit, so that the action initiated by the reactor protection system can control the process before the safety limit is reached. Some factors to be considered in determining this margin are: (a) the accuracy of the instrument; (b) the uncertainty in calibration; (c) the drift of the instrument; (d) the response time of the instrument and system. The reliability requirements for the instrument and control system are: the design techniques such as testability (including self-test capability when necessary), fail-safe characteristics, functional diversity, and diversity of component design and operation concepts must be used as practically as possible to prevent the loss of a certain safety function. For another example, according to the provisions on redundancy and diversity in GJB 843.11A-2006 "Design Safety Regulations for Submarine Nuclear Power Plants Part 11: Design Criteria for Protection Systems": In order for the protection system to meet the single failure criterion and provide the safety of the nuclear power plant, redundant technology must be used in the design. It includes redundancy of safety monitoring devices, redundancy of safety logic devices, or redundancy of the entire system. Diversity is a form of redundancy and should be used as much as possible in the design. Diversity generally includes functional diversity and equipment diversity. The use of the diversity principle can effectively overcome common cause failures. To this end, the protection signal can be optimized in terms of margin, margin, diversity and redundancy.
[0058] On the other hand, the protection signal is optimized according to the design constraints. A preliminary protection signal table can be established in advance as a design constraint. The preliminary protection signal in the table is a protection signal that can be implemented according to the design constraints. For a potential protection signal in the first potential protection signal list and the second potential protection signal list, by searching the preliminary protection signal table, it is determined whether the potential protection signal has a matching preliminary protection signal in the table. If so, it indicates that the potential protection signal is implementable, and the preliminary protection signal is directly placed in the preliminary protection signal list; if not, it indicates that the potential protection signal is not implementable, and further determines whether there is a replaceable preliminary protection signal for the potential protection signal. If so, it indicates that there is an implementable preliminary protection signal to replace the potential protection signal, so that the replaceable preliminary protection signal can be placed in the preliminary protection signal list. Generally speaking, the pre-established preliminary protection signal table contains preliminary protection signals that can replace potential protection signals. Otherwise, the user can input a preliminary protection signal that meets the requirements through the human-machine interface. Since the setting of the fuel micro-pile system involves a large number of personnel, the program can establish a collaborative workflow to allow multiple users to communicate on the substitutes of the potential protection signal to determine the available preliminary protection signal.
[0059] For example, the potential protection signals generated in steps 302 and 304 include: fuel pellet temperature signals and fuel cladding temperature, etc. Due to the design characteristics of the heat pipe micro-core, the core is compactly arranged, and the matrix 112 is in direct contact with the fuel rod 111 and the heat pipe 12 (refer to Figure 1 ), there is almost no air gap, and with the current measurement technology, the core block and cladding temperature of the fuel rod 111 cannot be directly monitored. Therefore, these potential protection signals are replaced with indirect signals - matrix high temperature to monitor the safety of the core 11.
[0060] Through the above-mentioned iterative optimization, a preliminary protection signal list is formed.
[0061] Figure 8 The present invention is a flowchart of a method for performing critical accident verification on a preliminary protection signal in a preliminary protection signal list to determine a protection signal setting value that meets a safety criterion according to an embodiment of the present invention. Figure 8Further details of step 306 are described as shown. In step 801, an accident analysis model is established. Specifically, a digital model is established according to the structure of the heat pipe micro-reactor and an accident analysis is performed to verify the effect of the preliminary protection signal. In step 802, the preliminary protection signal is added to the accident analysis model and an initial value is assigned. For example, the initial value of the temperature of the preliminary protection signal matrix high temperature obtained in the previous example is set as a basis for monitoring. In step 803, the key accident is analyzed using the accident analysis model, and the preliminary protection signal is iteratively optimized according to the analysis results to obtain the protection signal setting value and logic that can alleviate the key accident as the final protection signal. Here, the logic is a trigger logic related to the setting value. For example, "the matrix temperature reaches 800°C" is a protection signal, and the triggered logic includes "shutdown protection" and "triggering the residual discharge system after a certain delay".
[0062] For example, the shutdown protection signal and dedicated drive signal (such as substrate high temperature signal) were optimized and demonstrated for one of the key accidents, namely, the accident of complete loss of heat exchange capacity of multiple heat pipes in heat pipe micro-reactor. After the complete loss of heat exchange capacity of multiple heat pipes, the core heat exported outward by the heat pipes decreased, the local fuel assembly heated up, and the local temperature of the substrate continued to rise. When the substrate temperature reached the set value of substrate high 1, the shutdown was delayed for a certain time. The delay time during the shutdown process included the shutdown signal transmission time and the drum or safety rod action time. Subsequently, the power of the micro-reactor decreased. When the substrate reached the set value of substrate high 2 temperature, the dedicated system was put into use to continuously export heat after a certain delay or a certain delay after the shutdown. The delay time during the opening of the dedicated system needs to consider the transmission time of the dedicated system valve opening signal, the valve action time and the time to establish the natural signal. Subsequently, the temperature of the fuel core, cladding and substrate also decreased. The entire accident process met the safety criteria. The temperature of the fuel cladding and the temperature of the fuel core did not exceed the limit, which could effectively mitigate the accident. This shows that the substrate high temperature setting value meets the requirements and can be used as the final protection signal. Otherwise, the matrix high temperature setting value can be modified, the accident analysis model can be updated, and key accidents can be further verified to further demonstrate the safety of the heat pipe micro-reactor.
[0063] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.
[0064] Fig. 9 1 is a schematic diagram of a system implementation environment for determining a protection signal according to an example of the present application. Fig. 9 As shown, the system 900 is used to implement Figure 2The method shown may include an internal communication bus 901, a processor 902, a read-only memory (ROM) 903, a random access memory (RAM) 904, a communication port 905, and a hard disk 906. The internal communication bus 901 can implement data communication between the components of the system 900. The processor 902 can make judgments and issue prompts. In some embodiments, the processor 902 can be composed of one or more processors. The communication port 905 can implement data communication between the implementation environment 900 and the outside. In some embodiments, the implementation environment 900 can send and receive information and data from the network through the communication port 905. The implementation environment 900 can also include different forms of program storage units and data storage units, such as a hard disk 906, a read-only memory (ROM) 903 and a random access memory (RAM) 904, which can store various data files used for computer processing and / or communication, and possible program instructions executed by the processor 902. The processor executes these instructions to implement the main part of the method. The above-mentioned method for determining the protection signal may be implemented as a computer program, stored in the hard disk 906 , and loaded into the processor 902 for execution.
[0065] The present invention also includes a computer readable medium storing a computer program code, which implements the above method for determining a protection signal when executed by a processor.
[0066] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.
[0067] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.
[0068] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.
[0069] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values is as accurate as possible within the feasible range.
[0070] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.
Claims
1. A method for determining a protection signal of a heat pipe micro-stack, comprising the following steps: Obtaining safety criteria for the heat pipe micro-stack, wherein each safety criterion involves at least one protection signal; determining a first potential protection signal list according to the safety criterion, wherein the first potential protection signal list includes at least one potential protection signal; Obtaining a heat pipe micro-reactor accident list, wherein the heat pipe micro-reactor accident list includes at least one accident category, and each accident category includes one or more accidents; Determine a second potential protection signal list according to the heat pipe micro-reactor accident list, wherein the second potential protection signal list includes at least one potential protection signal; Optimize the feasibility of the first potential protection signal list and the second potential protection signal list according to the statutory protection signal requirements and design constraints, and determine a preliminary protection signal list; as well as The protection signals in the preliminary protection signal list are subjected to critical accident verification to determine the protection signal setting values that meet the safety criteria, thereby obtaining a final protection signal list.
2. The method according to claim 1, characterized in that The steps to obtain the safety criteria for the heat pipe micro-stack include: Extract the basic safety contents of nuclear power plant safety regulations regarding reactivity control, residual heat removal and radioactivity containment; Decomposing the basic security content into a plurality of security items; and A safety criterion of the heat pipe micro-stack is determined according to the plurality of safety items and design features of the heat pipe micro-stack.
3. The method according to claim 2, characterized in that The step of determining the safety criteria of the heat pipe micro-stack according to the plurality of safety items and the design features of the heat pipe micro-stack comprises: Establishing a design feature network of the heat pipe micro-stack; screening the design feature network for relevant design features related to a specific security entry among the plurality of security entries; and The safety criteria of the relevant design features are determined according to the specific safety items.
4. The method according to claim 3, characterized in that The design feature network includes multiple layers of nodes, wherein the first layer of nodes includes micro-repile system nodes and thermoelectric conversion system nodes, the second layer of nodes includes core nodes, heat pipe nodes, main heat exchanger nodes, waste heat exchanger nodes and stack nodes connected to the micro-repile system nodes, and regenerator nodes, turbine nodes, compressor nodes and motor nodes connected to the thermoelectric conversion system nodes, and the third layer of nodes includes fuel rod nodes, matrix nodes, reflector nodes, drum nodes and safety rod nodes connected to the core nodes, and each node is a design feature.
5. The method according to claim 1 or 2, characterized in that: The step of determining a first potential protection signal list according to the safety criterion comprises: extracting keywords in each security criterion to obtain corresponding potential protection signals; and The potential protection signals corresponding to the safety criteria are combined into the first potential protection signal list.
6. The method according to claim 1, characterized in that The step of determining a second potential protection signal list according to the heat pipe micro-reactor accident list comprises: Establish accident analysis model; For a specific accident category, use the accident analysis model to analyze the thermal-hydraulic response after the accident and potential mitigation paths; and A potential protection signal is formed according to the analysis result to form the second potential protection signal list.
7. The method according to claim 1, characterized in that The step of optimizing the feasibility of the first potential protection signal list and the second potential protection signal list according to the statutory protection signal requirements and the design constraints comprises: For any potential protection signal in the first potential protection signal list and the second potential protection signal list, determine whether any potential protection signal has a matching preliminary protection signal, if yes, put the preliminary protection signal into the preliminary protection signal list, if no, determine whether any potential protection signal has a replaceable preliminary protection signal, if yes, put the preliminary protection signal into the preliminary protection signal list, The preliminary protection signal is a protection signal that can be implemented according to the design constraint condition.
8. The method according to claim 1, characterized in that The step of performing critical accident verification on the preliminary protection signals in the preliminary protection signal list to determine the protection signal setting values that meet the safety criteria includes: Establish accident analysis model; Adding the preliminary protection signal to the accident analysis model and assigning an initial value; and The accident analysis model is used to analyze the critical accident, and the preliminary protection signal is iteratively optimized according to the analysis result to obtain the protection signal setting value that can alleviate the critical accident as the final protection signal.
9. The method according to claim 1, characterized in that The potential protection signal is a shutdown protection signal or a dedicated driving signal.
10. The method according to claim 1, characterized in that The accident categories include increased heat output from the heat pipe micro-reactor system, reduced heat removal capacity of the thermoelectric conversion system, abnormal reactivity and power distribution, decreased heat exchange capacity of the matrix / heat pipe, and expected transients that fail to shut down the reactor urgently.
11. A system for determining a protection signal of a heat pipe micro-stack, comprising: a memory for storing instructions executable by a processor; as well as A processor, configured to execute the instructions to implement the method according to any one of claims 1 to 10.
12. A computer storage medium storing computer program code, wherein the computer program code, when executed by a processor, implements the method according to any one of claims 1 to 10.