Overpressure protection method, device and equipment for main steam system and storage medium

Abstract

The invention discloses an overpressure protection method, device and equipment of a main steam system and a storage medium, relates to the technical field of nuclear power plants, and aims to provide effective and reasonable overpressure protection of the main steam system for a nuclear power plant and avoid overpressure conditions of the main steam system under various working conditions. The method comprises the steps of obtaining overpressure protection strategies triggered by a main steam system when a nuclear power plant is in different abnormal working conditions; in the process that the main steam system uses different overpressure protection strategies, the preset working condition of triggering overpressure protection by the main steam system is determined according to the pressure rising condition of the main steam system; according to the classification condition corresponding to the preset working condition, determining an acceptance criterion of the preset working condition; and on the basis that the acceptance criterion is met, capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working condition is determined, and overpressure protection of the main steam system is executed according to the capacity configuration information of the overpressure discharge equipment.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear power plants, and in particular to an overpressure protection method, device, equipment and storage medium for a main steam system. Background Art

[0002] The main steam system is an important heat dissipation pathway during the normal operation and accidents of nuclear power plants. The integrity of its pressure boundary is of great significance to the safe operation of nuclear power plants and the smooth removal of core heat after accidents. In order to avoid unacceptable overpressure accidents in the main steam system of pressurized water reactor nuclear power plants and thus damage the pressure boundary of the main steam system, valves for discharging steam are usually set on the main steam pipeline behind the steam generator outlet. Through these valves and the control and protection system of the nuclear power plant, the overpressure protection function of the main steam system is completed.

[0003] In the related art, the overpressure protection of the main steam system is mainly designed based on experience, resulting in an overly redundant capacity configuration, making it difficult to reasonably configure the main steam system safety valve and unable to achieve the expected overpressure protection effect. Summary of the invention

[0004] In view of this, the present application provides an overpressure protection method, device, equipment and storage medium for a main steam system, the main purpose of which is to solve the problem in the prior art that the main steam system safety valve is difficult to reasonably configure and the expected overpressure protection effect cannot be achieved.

[0005] According to a first aspect of the present application, a method for overpressure protection of a main steam system is provided, the method comprising:

[0006] Obtain the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal conditions;

[0007] When the main steam system uses different overpressure protection strategies, the preset working condition for triggering overpressure protection of the main steam system is determined according to the pressure rise of the main steam system;

[0008] Determining the acceptance criteria of the preset working condition according to the classification corresponding to the preset working condition;

[0009] On the basis of meeting the acceptance criteria, determine the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions;

[0010] Overpressure protection is provided for the main steam system according to the capacity configuration information of the overpressure relief equipment.

[0011] Furthermore, in the process of using different overpressure protection strategies for the main steam system, determining the preset working condition for triggering overpressure protection of the main steam system according to the pressure rise of the main steam system specifically includes:

[0012] In the process of using different overpressure protection strategies for the main steam system, the first operating condition for triggering overpressure protection of the main steam system is determined from the direction of core heat generation according to the pressure rise of the main steam system;

[0013] In the process of using different overpressure protection strategies for the main steam system, the second operating condition of the main steam system triggering overpressure protection is determined from the steam discharge direction according to the pressure rise of the main steam system;

[0014] The first operating condition and the second operating condition are combined to determine a preset operating condition for triggering overpressure protection of the main steam system.

[0015] Furthermore, in the process of using different overpressure protection strategies for the main steam system, determining the first operating condition for triggering overpressure protection of the main steam system from the direction of core heat generation according to the pressure rise of the main steam system specifically includes:

[0016] When using different overpressure protection strategies in the main steam system, the influence of different control rod withdrawal rates on the pressure rise of the main steam system is evaluated;

[0017] According to the evaluation results of the impact of the pressure rise in the main steam system, the control rod withdrawal situation with the largest pressure rise in the main steam system is determined as the first operating condition for triggering overpressure protection of the main steam system.

[0018] Furthermore, in the process of using different overpressure protection strategies for the main steam system, determining the second operating condition for triggering overpressure protection of the main steam system from the steam discharge direction according to the pressure rise of the main steam system specifically includes:

[0019] When using different overpressure protection strategies for the main steam system, select valves with closing functions on the normal discharge path of the main steam system;

[0020] Evaluate the pressure increase of the main steam system caused by the closing of different valves, and determine the closing moment of the valve with the largest pressure increase in the main steam system as the second operating condition for triggering overpressure protection of the main steam system.

[0021] Furthermore, the acceptance criteria of the preset working condition are determined according to the classification corresponding to the preset working condition, specifically including:

[0022] Classify the preset working conditions from the perspective of probability of occurrence to obtain the classification of the preset working conditions;

[0023] On the basis of ensuring that the indicators of the main steam system during the accident process meet the design requirements, corresponding acceptance criteria are selected according to the classification of the preset working conditions to obtain the acceptance criteria of the preset working conditions.

[0024] Furthermore, in the process of using different overpressure protection strategies for the main steam system, after determining the preset working condition for triggering overpressure protection of the main steam system according to the pressure rise of the main steam system, the method further includes:

[0025] According to the preset operating conditions, a short-term overpressure accident that poses a risk to the main steam pressure boundary is determined, and a shutdown protection signal is set according to the pressure rise caused by the development of the short-term overpressure accident. The shutdown protection signal is triggered when any of the following scenarios is met: the pressurizer pressure reaches a first preset threshold, the main steam system pressure reaches a second preset threshold, the core nuclear power reaches a third preset threshold, and the turbine shutdown and condenser discharge failure are met.

[0026] Furthermore, on the basis of satisfying the acceptance criteria, determining the capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working conditions specifically includes:

[0027] Obtain the valve characteristics of the safety valve of the main steam system during overpressure discharge;

[0028] Analyzing the preset operating condition at the design pressure according to the valve characteristics of the safety valve to determine the minimum valve displacement required to meet the acceptance criteria under a given shutdown protection signal;

[0029] On the basis of setting the valve opening pressure and the valve displacement corresponding to the pressure, the preset working condition is evaluated. If the evaluation result does not meet the acceptance criteria, the valve displacement is increased until the evaluation result meets the acceptance criteria, and the valve displacement determined to meet the acceptance criteria is used as the minimum valve displacement;

[0030] According to the minimum displacement of the valve, the minimum value between the empirical maximum displacement of the valve and the set maximum displacement of the valve is selected as the maximum displacement of the valve, the empirical maximum displacement of the valve is calculated based on the ratio of the maximum displacement of the valve to the minimum displacement of the valve not exceeding the preset value, and the set maximum displacement of the valve is the maximum displacement of the valve acceptable to the set working condition obtained by selecting the event working condition evaluation, and the event working condition includes the single valve mistakenly opened and the single valve stuck open;

[0031] According to the valve opening pressure, the maximum displacement of the valve and the minimum displacement of the valve, the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions is determined.

[0032] According to a second aspect of the present application, an overpressure protection device for a main steam system is provided, the device comprising:

[0033] An acquisition unit, used to acquire the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal operating conditions;

[0034] A first determination unit is used to determine a preset operating condition for triggering overpressure protection of the main steam system according to a pressure rise of the main steam system during the process of using different overpressure protection strategies of the main steam system;

[0035] A second determining unit, configured to determine an acceptance criterion for a preset working condition according to a classification corresponding to the preset working condition;

[0036] A third determination unit is used to determine the capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working conditions on the basis of satisfying the acceptance criteria;

[0037] The overpressure protection unit is used to provide overpressure protection for the main steam system according to the capacity configuration information of the overpressure relief equipment.

[0038] Furthermore, the first determining unit includes:

[0039] A first determination module is used to determine the first operating condition of the main steam system triggering overpressure protection from the direction of core heat generation according to the pressure rise of the main steam system during the process of using different overpressure protection strategies for the main steam system;

[0040] The second determination module determines the second operating condition of the main steam system triggering overpressure protection from the steam discharge direction according to the pressure rise of the main steam system during the process of using different overpressure protection strategies of the main steam system;

[0041] A combining module is used to combine the first operating condition and the second operating condition to determine a preset operating condition for triggering overpressure protection of the main steam system.

[0042] Furthermore, the first determining module is specifically configured to:

[0043] When using different overpressure protection strategies in the main steam system, the influence of different control rod withdrawal rates on the pressure rise of the main steam system is evaluated;

[0044] According to the evaluation results of the impact of the pressure rise in the main steam system, the control rod withdrawal situation with the largest pressure rise in the main steam system is determined as the first operating condition for triggering overpressure protection of the main steam system.

[0045] Furthermore, the second determining module is specifically configured to:

[0046] When using different overpressure protection strategies for the main steam system, select valves with closing functions on the normal discharge path of the main steam system;

[0047] Evaluate the pressure increase of the main steam system caused by the closing of different valves, and determine the closing moment of the valve with the largest pressure increase in the main steam system as the second operating condition for triggering overpressure protection of the main steam system.

[0048] Furthermore, the second determining unit is specifically configured to:

[0049] Classify the preset working conditions from the perspective of probability of occurrence to obtain the classification of the preset working conditions;

[0050] On the basis of ensuring that the indicators of the main steam system during the accident process meet the design requirements, corresponding acceptance criteria are selected according to the classification of the preset working conditions to obtain the acceptance criteria of the preset working conditions.

[0051] Furthermore, the device also includes:

[0052] A setting unit is used to determine, during the process of using different overpressure protection strategies for the main steam system, a preset operating condition for triggering overpressure protection of the main steam system according to the pressure rise of the main steam system, and then, according to the preset operating condition, determine a short-term overpressure accident that poses a risk to the main steam pressure boundary, and set a shutdown protection signal for the pressure rise caused by the development of the short-term overpressure accident. The shutdown protection signal is triggered when any of the following scenarios is met: the pressurizer pressure reaches a first preset threshold, the main steam system pressure reaches a second preset threshold, the core nuclear power reaches a third preset threshold, and the turbine shutdown and condenser discharge failure are met.

[0053] Furthermore, the third determining unit is specifically configured to:

[0054] Obtain the valve characteristics of the safety valve of the main steam system during overpressure discharge;

[0055] Analyzing the preset operating condition at the design pressure according to the valve characteristics of the safety valve to determine the minimum valve displacement required to meet the acceptance criteria under a given shutdown protection signal;

[0056] On the basis of setting the valve opening pressure and the valve displacement corresponding to the pressure, the preset working condition is evaluated. If the evaluation result does not meet the acceptance criteria, the valve displacement is increased until the evaluation result meets the acceptance criteria, and the valve displacement determined to meet the acceptance criteria is used as the minimum valve displacement;

[0057] According to the minimum displacement of the valve, the minimum value between the empirical maximum displacement of the valve and the set maximum displacement of the valve is selected as the maximum displacement of the valve, the empirical maximum displacement of the valve is calculated based on the ratio of the maximum displacement of the valve to the minimum displacement of the valve not exceeding the preset value, and the set maximum displacement of the valve is the maximum displacement of the valve acceptable to the set working condition obtained by selecting the event working condition evaluation, and the event working condition includes the single valve mistakenly opened and the single valve stuck open;

[0058] According to the valve opening pressure, the maximum displacement of the valve and the minimum displacement of the valve, the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions is determined.

[0059] According to a third aspect of the present application, a storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the overpressure protection method of the main steam system is implemented.

[0060] According to the fourth aspect of the present application, an overpressure protection device for a main steam system is provided, comprising a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor implements the above-mentioned overpressure protection method for the main steam system when executing the program.

[0061] By means of the above technical scheme, the present application provides a method, device, equipment and storage medium for overpressure protection of the main steam system. Compared with the current method of realizing overpressure protection of the main steam system based on empirical design, the present application obtains the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal working conditions. In the process of using different overpressure protection strategies in the main steam system, the preset working condition for triggering overpressure protection of the main steam system is determined according to the pressure rise of the main steam system, and the acceptance criteria of the preset working condition are determined according to the classification corresponding to the preset working condition. On the basis of meeting the acceptance criteria, the capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working condition is determined, and the overpressure protection of the main steam system is performed according to the capacity configuration information of the overpressure discharge equipment. The whole process uses the capacity configuration information of the overpressure discharge equipment to reasonably configure the safety valve of the main steam system on the basis of meeting the acceptance criteria, which can provide effective and reasonable overpressure protection of the main steam system for the nuclear power plant, avoid overpressure of the main steam system under various working conditions, and ensure that the main steam system achieves the expected overpressure protection effect.

[0062] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0064] Figure 1 is a flow chart of an overpressure protection method for a main steam system in one embodiment of the present application;

[0065] Figure 2 yes Figure 1A schematic flow chart of a specific implementation of step 102;

[0066] Figure 3 yes Figure 1 A schematic flow chart of a specific implementation of step 103;

[0067] Figure 4 yes Figure 1 A schematic flow chart of a specific implementation of step 104;

[0068] Figure 5 It is a schematic diagram of the process of capacity configuration of the overpressure discharge equipment in one embodiment of the present application;

[0069] Figure 6 is a schematic structural diagram of an overpressure protection device for a main steam system in one embodiment of the present application;

[0070] Figure 7 It is a schematic diagram of the device structure of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0071] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0072] In the related art, the overpressure protection of the main steam system is mainly designed based on experience, resulting in an overly redundant capacity configuration, making it difficult to reasonably configure the main steam system safety valve and unable to achieve the expected overpressure protection effect.

[0073] In order to solve this problem, this embodiment provides an overpressure protection method for the main steam system, such as Figure 1 As shown, the following steps are included:

[0074] 101. Obtain the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal operating conditions.

[0075] In this embodiment, the main steam engine serves as an important heat dissipation pathway during normal operation and accidents of the nuclear power plant. If the nuclear power plant is in an abnormal operating condition, the main steam engine will be triggered to start the overpressure protection strategy. The abnormal operating conditions of the nuclear power plant here mainly include but are not limited to turbine shutdown accidents, triggered reactor shutdown accidents, etc.

[0076] Considering that the steam discharge mode of the main steam system of a nuclear power plant is different under different abnormal conditions, the main steam system will trigger the overpressure protection strategy under different steam discharge modes accordingly. In one abnormal scenario, if any accident or failure occurs in the nuclear power plant, if the shutdown or shutdown is not triggered, the steam of the main steam system is discharged through the steam turbine. The accident or failure here refers to some normal operation transients or failures that will not cause shutdown, such as small abnormal changes in functional rate and small abnormal changes in compliance, etc.; in another abnormal scenario, if any accident or failure occurs in the nuclear power plant, if the shutdown is triggered, the shutdown signal triggers the turbine shutdown. After the turbine is shut down, if the valve between the inlet of the condenser of the steam main steam system is not closed, the valve opening command is sent to the condenser through the control and protection system, and the steam of the main steam system is discharged through the condenser; accordingly, if the valve between the inlet of the condenser of the steam main steam system is closed, the steam of the main steam system is discharged through the safety valve on the steam pipeline at the outlet of the steam generator. The shutdown signal here is usually issued by the reactor protection system. In some power plant designs, in addition to the reactor protection system, the shutdown signal can also be issued through a variety of protection systems. It is understandable that there may be many situations that trigger the shutdown, such as the main steam system valve being closed by mistake, the core control rod being pulled out by mistake, and some circuit flows being unexpectedly reduced. As long as the accident causes certain parameters to exceed the value set by the shutdown signal in the reactor protection system, the shutdown will be triggered, and the shutdown signal will then trigger the turbine shutdown. In addition, the turbine will not only be triggered to shut down according to the shutdown signal, but may also be triggered to shut down according to the turbine's own protection logic. In another abnormal scenario, if the steam turbine is shut down at the time of the initiating event and the valve between the main steam system and the condenser outlet is not closed, the valve opening command is sent to the condenser through the control and protection system, and the steam from the main steam system is discharged through the condenser; correspondingly, if the valve between the condenser inlet of the main steam system is closed, the control and protection system sends an emergency shutdown signal based on the valve status between the steam turbine and the steam pipeline to the condenser, and the steam from the main steam system is discharged through the safety valve on the steam pipeline at the steam generator outlet.

[0077] The executor of the embodiment of the present invention can be the overpressure protection device of the main steam system. By obtaining the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal operating conditions, the overpressure protection of the main steam system during the steam discharge process can be implemented through different overpressure protection strategies to ensure the safe operation of the nuclear power plant.

[0078] 102. When the main steam system uses different overpressure protection strategies, the preset operating conditions for triggering overpressure protection of the main steam system are determined according to the pressure rise of the main steam system.

[0079] In this embodiment, the preset operating condition refers to the operating condition that will cause the main steam system pressure to rise rapidly. There are many reasons for the rapid pressure rise. For example, the core is in a high power state, and the uncontrollable withdrawal of control rods during the steam discharge process will cause the main steam system pressure to rise rapidly.

[0080] 103. Determine the acceptance criteria for the preset working condition according to the classification corresponding to the preset working condition.

[0081] In this embodiment, the process of classifying the preset operating conditions can classify the preset operating conditions from the perspective of occurrence probability. Specifically, the operating conditions of the nuclear power plant can be divided into four categories according to the expected probability of reactor accidents and the possible radioactive consequences, namely, operating conditions I / operating conditions II / operating conditions III / operating conditions IV. For operating condition I, it refers to normal operation and operating transients, including normal startup, shutdown and steady-state operation, extreme operation with allowable deviations, and operating transients. Such operating conditions occur frequently and do not require shutdown. The control system is relied on to perform conditions to the required state and resume stable operation. For operating condition II, it refers to medium-frequency events, or expected operating events. All operating processes that are expected to deviate from normal operation once or several times during the operating life of the nuclear power plant may be shut down, but will not cause damage to the original fuel components or overpressure of the primary and secondary circuit systems. As long as the protection system can operate normally, it will not cause accident conditions. For operating condition III, it refers to rare accidents with low occurrence power. In order to prevent or limit radiation hazards to the environment, special safety facilities need to be put into operation, such as thermal rupture of a single steam generator. Condition IV refers to an extreme accident with an extremely low probability of occurrence. Once it occurs, a large amount of radioactive material will be released, so it must be taken into consideration in the design of nuclear power plants, such as a large rupture of the secondary circuit steam pipe.

[0082] Accordingly, corresponding acceptance criteria are proposed according to the classification of nuclear power plant operating conditions to ensure that the pressure of the main steam system of the nuclear power plant during an accident does not exceed a preset pressure, which is preferably 110% of the design pressure.

[0083] 104. On the basis of meeting the acceptance criteria, determine the capacity configuration information of the overpressure relief equipment of the main steam system under the preset operating conditions.

[0084] Taking into account that the main steam system performs overpressure discharge through the safety valve, the capacity configuration information of the overpressure discharge equipment of the steam system under the preset working conditions can be determined based on the valve characteristics of the safety valve. The specific valve characteristics include the valve opening set pressure and the valve discharge volume (including the maximum valve displacement and the minimum valve displacement).

[0085] Specifically, under the premise of setting the valve opening set pressure, the preset operating conditions can be analyzed for the first time to determine the minimum valve displacement required to meet the acceptance criteria. Then, under the premise of setting the valve opening pressure, the preset operating conditions can be analyzed for the second time to evaluate the preset operating conditions. The minimum valve displacement that meets the acceptance criteria can be determined based on the evaluation results, and the maximum valve displacement can be determined based on the minimum valve displacement. The capacity configuration information of the overpressure relief equipment of the main steam system under the preset operating conditions can be determined based on the valve opening set pressure, the maximum valve displacement and the minimum valve displacement.

[0086] 105. Provide overpressure protection for the main steam system according to the capacity configuration information of the overpressure relief equipment.

[0087] It is understandable that in order to allow the capacity configuration information of the overpressure relief equipment to cover more operating conditions during the operation of the nuclear power plant, in addition to the above-mentioned preset operating conditions, other operating conditions that cause the pressure of the main steam system to rise are selected for evaluation for various operating conditions of the nuclear power plant. The capacity information of the overpressure relief equipment can also be used to determine whether the overpressure protection function is met. If not, the valve displacement is further increased and re-evaluated until the overpressure protection function is met, thereby providing effective and reasonable overpressure protection for the main steam system of the nuclear power plant.

[0088] Compared with the current method of realizing overpressure protection of the main steam system based on empirical design, the overpressure protection method of the main steam system provided in the embodiment of the present application obtains the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal working conditions. In the process of using different overpressure protection strategies in the main steam system, the preset working condition for triggering overpressure protection of the main steam system is determined according to the pressure rise of the main steam system, and the acceptance criteria of the preset working condition are determined according to the classification corresponding to the preset working condition. On the basis of meeting the acceptance criteria, the capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working condition is determined, and the overpressure protection of the main steam system is performed according to the capacity configuration information of the overpressure discharge equipment. The whole process uses the capacity configuration information of the overpressure discharge equipment to reasonably configure the safety valve of the main steam system on the basis of meeting the acceptance criteria, which can provide effective and reasonable overpressure protection of the main steam system for the nuclear power plant, avoid overpressure of the main steam system under various working conditions, and ensure that the main steam system achieves the expected overpressure protection effect.

[0089] In actual application scenarios, different overpressure protection strategies under different abnormal conditions are taken into consideration. The implementation process of overpressure protection strategies under different conditions mainly includes the following two aspects: on the one hand, by setting corresponding automatic protection signals in the control and protection system, such as shutdown signal, turbine shutdown signal, and condenser steam discharge signal, the shutdown signal, turbine shutdown, and condenser steam discharge can be realized; on the other hand, by setting the safety valve of the steam pipeline at the outlet of the steam generator in the main steam system and setting the appropriate opening pressure, the valve can be opened for pressure relief and discharge when the steam pressure rises to a certain level. The actual process of the configuration of the safety valve of the main steam system mainly includes the following contents. Usually, a suitable computer program is selected to model the nuclear power plant. On the basis of meeting the acceptance criteria, the capacity configuration and accident transient evaluation of different working conditions can be carried out to determine the capacity configuration information of the overpressure discharge equipment of the main steam system under different working conditions.

[0090] Specifically, in the above embodiment, Figure 2 As shown, step 102 includes the following steps:

[0091] 201. When the main steam system uses different overpressure protection strategies, the first operating condition for triggering overpressure protection of the main steam system is determined from the direction of core heat generation according to the pressure rise of the main steam system.

[0092] 202. When the main steam system uses different overpressure protection strategies, the second operating condition for triggering overpressure protection of the main steam system is determined from the steam discharge direction according to the pressure rise of the main steam system.

[0093] 203. Combine the first operating condition and the second operating condition to determine a preset operating condition for triggering overpressure protection of the main steam system.

[0094] In this embodiment, the preset operating condition refers to the operating condition that will cause the pressure of the main steam system to rise rapidly. Considering the different reasons for the rapid pressure rise, the preset operating condition can be screened from two directions.

[0095] On the one hand, by screening the preset operating conditions from the direction of core heat generation, the influence of different control rod withdrawal rates on the pressure rise of the main steam system can be evaluated when the main steam system uses different overpressure protection strategies; according to the evaluation results of the influence of the pressure rise of the main steam system, the control rod withdrawal situation with the largest pressure increase in the main steam system is determined as the first operating condition for triggering overpressure protection of the main steam system; specifically, for such preset operating conditions, it can be assumed that the exhaust path of the main steam system is normal at the beginning, but the core power suddenly increases due to the uncontrollable withdrawal of control rods, and the influence of different control rod withdrawal rates on the pressure rise of the main steam bear is evaluated, and the withdrawal situation that causes the largest pressure increase is determined, and this situation is taken as the first operating condition.

[0096] On the other hand, by screening the preset operating conditions from the steam discharge direction, the valves with closing functions on the normal discharge path of the main steam system can be screened during the use of different overpressure protection strategies in the main steam system; the pressure increase of the main steam system caused by the closing of different valves can be evaluated, so as to determine the closing moment of the valve with the largest pressure increase in the main steam system as the second operating condition for triggering overpressure protection of the main steam system. Specifically, for such preset operating conditions, it can be assumed that the core is in a high-power state, and the valves with closing functions on the normal discharge path of the main steam system can be screened first, and the main steam pressure increase caused by the closing of different valves can be evaluated. The valve that causes the largest pressure increase is determined, and the instantaneous closing of the valve is used as the second operating condition.

[0097] Specifically, in the above embodiment, Figure 3 As shown, step 103 includes the following steps:

[0098] 301. Classify the preset working conditions from the perspective of probability of occurrence to obtain classification of the preset working conditions.

[0099] 302. On the basis of ensuring that the indicators of the main steam system during the accident process meet the design requirements, the corresponding acceptance criteria are selected according to the classification of the preset operating conditions to obtain the acceptance criteria of the preset operating conditions.

[0100] In the process of classifying the preset working conditions, the classification of the preset working conditions can be determined from the perspective of the probability of occurrence, and the corresponding acceptance criteria can be selected according to different classification situations. For example, according to the classification of the working conditions of the nuclear power plant, if it is divided into Class I / II / III / IV working conditions, it is ensured that the indicators of the main steam system of the nuclear power plant during the accident process meet the design requirements, for example, the pressure indicator of the main steam system does not exceed 110% of the design pressure.

[0101] Furthermore, considering the overpressure protection condition that may cause risks to the main steam pressure boundary, this type of overpressure protection condition can limit the pressure rise in two ways: one is to set a timely and effective shutdown signal to quickly reduce the heat generation of the core; the other is to set a sufficient steam discharge path to discharge the steam in time. Correspondingly, after step 103, the method also includes the following steps: according to the preset conditions, determine the short-term overpressure accident that causes risks to the main steam pressure boundary, set a shutdown protection signal for the pressure rise caused by the development of the short-term overpressure accident, where the shutdown protection signal is triggered when any of the following scenarios are met: the regulator pressure reaches the first preset threshold, the main steam system pressure reaches the second preset threshold, the core nuclear power reaches the third preset threshold, and the turbine shutdown and condenser discharge failure are consistent.

[0102] Specifically, in the above embodiment, Figure 4 As shown, step 104 includes the following steps:

[0103] 401. Obtain the valve characteristics of the safety valve of the main steam system during overpressure discharge.

[0104] 402. Analyze the preset operating condition under the design pressure according to the valve characteristics of the safety valve to determine the minimum valve displacement required to meet the acceptance criteria under a given shutdown protection signal.

[0105] 403. Based on the set valve opening pressure and the valve displacement corresponding to the pressure, the preset working condition is evaluated.

[0106] 404. If the evaluation result does not meet the acceptance criteria, increase the valve displacement until the evaluation result meets the acceptance criteria, and use the valve displacement determined to meet the acceptance criteria as the minimum valve displacement.

[0107] 405. According to the minimum valve displacement, a minimum value is selected between the empirical maximum valve displacement and the set maximum valve displacement as the maximum valve displacement.

[0108] 406. Determine the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions according to the valve opening pressure, the maximum displacement of the valve and the minimum displacement of the valve.

[0109] Among them, the empirical valve maximum displacement is calculated based on the ratio of the valve maximum displacement to the valve minimum displacement not exceeding the preset value, and the set valve maximum displacement is the maximum valve displacement acceptable to the set operating condition obtained by selecting the event operating condition evaluation. The event operating condition includes the accidental opening of a single valve and the stuck opening of a single valve.

[0110] In this embodiment, the capacity configuration information of the overpressure discharge related equipment mainly includes the valve opening set pressure and the valve discharge volume, and the valve discharge volume includes the maximum valve discharge volume and the minimum valve discharge volume. Figure 5 The flow diagram of overpressure relief equipment capacity configuration shown in the figure is as follows. First, it is assumed that the valve opening set pressure is the design pressure P of the main steam system. n , analyze the preset operating conditions under this pressure, and determine the minimum valve displacement Q required to meet the acceptance criteria taking into account the given shutdown protection signal min , then set the first group of valve opening pressure to (P n -ΔP), the valve displacement corresponding to this pressure is Q min / 2, set the second valve opening pressure to (P n +ΔP), the valve displacement corresponding to this pressure is Q min / 2, where ΔP is considered to be P n / 100, evaluate the preset working conditions based on the valve opening pressure and the displacement corresponding to the pressure. If the acceptance criteria are not met, increase the displacement of each group of valves until the acceptance criteria are met, and use the valve displacement as the minimum displacement requirement. After determining the minimum displacement of each group of valves, first determine the upper limit Q of the maximum displacement of the valve based on industrial experience max1 The process can be determined according to the ratio range of the maximum and minimum displacement of the valve, and then a single valve mis-opening and a single valve stuck-opening event are selected for evaluation to determine the acceptable maximum valve displacement Q under these two conditions. max2 , and finally in Q max1 and Q max2 The smaller of the two maximum displacements is selected as the maximum displacement of the safety valve.

[0111] Further, as Figure 1-Figure 4 The specific implementation of the method, the embodiment of the present application provides an overpressure protection device for a main steam system, such as Figure 6 As shown, the device includes: an acquisition unit 51, a first determination unit 52, a second determination unit 53, a third determination unit 54, and an overpressure protection unit 55.

[0112] An acquisition unit 51 is used to acquire an overpressure protection strategy triggered by a main steam system when the nuclear power plant is in different abnormal operating conditions;

[0113] A first determining unit 52 is used to determine a preset operating condition for triggering overpressure protection of the main steam system according to a pressure rise of the main steam system during the process of using different overpressure protection strategies in the main steam system;

[0114] A second determining unit 53 is used to determine the acceptance criteria of the preset working condition according to the classification corresponding to the preset working condition;

[0115] The third determination unit 54 is used to determine the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions on the basis of satisfying the acceptance criteria;

[0116] The overpressure protection unit 55 is used to provide overpressure protection for the main steam system according to the capacity configuration information of the overpressure relief equipment.

[0117] Compared with the current method of realizing overpressure protection of the main steam system based on empirical design, the overpressure protection device of the main steam system provided by the embodiment of the present invention obtains the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal working conditions. In the process of using different overpressure protection strategies in the main steam system, the preset working condition for triggering overpressure protection of the main steam system is determined according to the pressure rise of the main steam system, and the acceptance criteria of the preset working condition are determined according to the classification corresponding to the preset working condition. On the basis of meeting the acceptance criteria, the capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working condition is determined, and the overpressure protection of the main steam system is performed according to the capacity configuration information of the overpressure discharge equipment. The whole process reasonably configures the safety valve of the main steam system using the capacity configuration information of the overpressure discharge equipment on the basis of meeting the acceptance criteria, which can provide effective and reasonable overpressure protection of the main steam system for the nuclear power plant, avoid overpressure of the main steam system under various working conditions, and ensure that the main steam system achieves the expected overpressure protection effect.

[0118] In a specific application scenario, the first determining unit includes:

[0119] A first determination module is used to determine the first operating condition of the main steam system triggering overpressure protection from the direction of core heat generation according to the pressure rise of the main steam system during the process of using different overpressure protection strategies for the main steam system;

[0120] The second determination module determines the second operating condition of the main steam system triggering overpressure protection from the steam discharge direction according to the pressure rise of the main steam system during the process of using different overpressure protection strategies of the main steam system;

[0121] A combining module is used to combine the first operating condition and the second operating condition to determine a preset operating condition for triggering overpressure protection of the main steam system.

[0122] In a specific application scenario, the first determining module is specifically used to:

[0123] When using different overpressure protection strategies in the main steam system, the influence of different control rod withdrawal rates on the pressure rise of the main steam system is evaluated;

[0124] According to the evaluation results of the impact of the pressure rise in the main steam system, the control rod withdrawal situation with the largest pressure rise in the main steam system is determined as the first operating condition for triggering overpressure protection of the main steam system.

[0125] In a specific application scenario, the second determining module is specifically used to:

[0126] When using different overpressure protection strategies for the main steam system, select valves with closing functions on the normal discharge path of the main steam system;

[0127] Evaluate the pressure increase of the main steam system caused by the closing of different valves, and determine the closing moment of the valve with the largest pressure increase in the main steam system as the second operating condition for triggering overpressure protection of the main steam system.

[0128] In a specific application scenario, the second determining unit is specifically used to:

[0129] Classify the preset working conditions from the perspective of probability of occurrence to obtain the classification of the preset working conditions;

[0130] On the basis of ensuring that the indicators of the main steam system during the accident process meet the design requirements, corresponding acceptance criteria are selected according to the classification of the preset working conditions to obtain the acceptance criteria of the preset working conditions.

[0131] In a specific application scenario, the device further includes:

[0132] A setting unit is used to determine, during the process of using different overpressure protection strategies for the main steam system, a preset operating condition for triggering overpressure protection of the main steam system according to the pressure rise of the main steam system, and then, according to the preset operating condition, determine a short-term overpressure accident that poses a risk to the main steam pressure boundary, and set a shutdown protection signal for the pressure rise caused by the development of the short-term overpressure accident. The shutdown protection signal is triggered when any of the following scenarios is met: the pressurizer pressure reaches a first preset threshold, the main steam system pressure reaches a second preset threshold, the core nuclear power reaches a third preset threshold, and the turbine shutdown and condenser discharge failure are met.

[0133] In a specific application scenario, the third determining unit is specifically used to:

[0134] Obtain the valve characteristics of the safety valve of the main steam system during overpressure discharge;

[0135] Analyzing the preset operating condition at the design pressure according to the valve characteristics of the safety valve to determine the minimum valve displacement required to meet the acceptance criteria under a given shutdown protection signal;

[0136] On the basis of setting the valve opening pressure and the valve displacement corresponding to the pressure, the preset working condition is evaluated. If the evaluation result does not meet the acceptance criteria, the valve displacement is increased until the evaluation result meets the acceptance criteria, and the valve displacement determined to meet the acceptance criteria is used as the minimum valve displacement;

[0137] According to the minimum displacement of the valve, the minimum value between the empirical maximum displacement of the valve and the set maximum displacement of the valve is selected as the maximum displacement of the valve, the empirical maximum displacement of the valve is calculated based on the ratio of the maximum displacement of the valve to the minimum displacement of the valve not exceeding the preset value, and the set maximum displacement of the valve is the maximum displacement of the valve acceptable to the set working condition obtained by selecting the event working condition evaluation, and the event working condition includes the single valve mistakenly opened and the single valve stuck open;

[0138] According to the valve opening pressure, the maximum displacement of the valve and the minimum displacement of the valve, the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions is determined.

[0139] Based on the above Figure 1-Figure 4 The method shown in the embodiment of the present application accordingly provides a storage medium on which a computer program is stored, and when the program is executed by a processor, the above-mentioned Figure 1-Figure 4 The overpressure protection method of the main steam system is shown.

[0140] Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each implementation scenario of the present application.

[0141] Based on the above Figure 1-Figure 4 The method shown, and Figure 6 In order to achieve the above-mentioned purpose, the embodiment of the present application also provides a physical device for overpressure protection of the main steam system, which can be a computer, a smart phone, a tablet computer, a smart watch, a server, or a network device, etc. The physical device includes a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to achieve the above-mentioned Figure 1-Figure 4 The overpressure protection method of the main steam system is shown.

[0142] Optionally, the physical device may also include a user interface, a network interface, a camera, a radio frequency (RF) circuit, a sensor, an audio circuit, a WI-FI module, etc. The user interface may include a display, an input unit such as a keyboard, etc., and the optional user interface may also include a USB interface, a card reader interface, etc. The network interface may optionally include a standard wired interface, a wireless interface (such as a WI-FI interface), etc.

[0143] In an exemplary embodiment, see Figure 7The physical device includes a communication bus, a processor, a memory and a communication interface, and may also include an input / output interface and a display device, wherein each functional unit can communicate with each other through the bus. The memory stores a computer program, and the processor is used to execute the program stored in the memory and execute the overpressure protection method of the main steam system in the above embodiment.

[0144] Those skilled in the art will appreciate that the physical equipment structure for overpressure protection of a main steam system provided in this embodiment does not constitute a limitation on the physical equipment, and may include more or fewer components, or a combination of certain components, or different arrangements of components.

[0145] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the physical device of the overpressure protection of the main steam system, and supports the operation of the information processing program and other software and / or programs. The network communication module is used to realize the communication between the components inside the storage medium, and the communication with other hardware and software in the information processing physical device.

[0146] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform, or by hardware. By applying the technical solution of the present application, compared with the current existing methods, the present application uses the capacity configuration information of the overpressure discharge equipment to reasonably configure the main steam system safety valve on the basis of meeting the acceptance criteria, which can provide effective and reasonable overpressure protection for the main steam system of the nuclear power plant, avoid overpressure in the main steam system under various working conditions, and ensure that the main steam system achieves the expected overpressure protection effect.

[0147] Those skilled in the art will appreciate that the accompanying drawings are only schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily necessary for implementing the present application. Those skilled in the art will appreciate that the modules in the devices in the implementation scenario can be distributed in the devices of the implementation scenario according to the description of the implementation scenario, or can be changed accordingly and located in one or more devices different from the present implementation scenario. The modules of the above-mentioned implementation scenario can be combined into one module, or can be further split into multiple submodules.

[0148] The above serial numbers of this application are only for description and do not represent the advantages and disadvantages of the implementation scenarios. The above disclosure is only a few specific implementation scenarios of this application, but this application is not limited to them, and any changes that can be thought of by technicians in this field should fall within the scope of protection of this application.

Claims

1. A method for overpressure protection of a main steam system, characterized in that: include: Obtain the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal conditions; When the main steam system uses different overpressure protection strategies, the preset working condition for triggering overpressure protection of the main steam system is determined according to the pressure rise of the main steam system; Determining the acceptance criteria of the preset working condition according to the classification corresponding to the preset working condition; On the basis of meeting the acceptance criteria, determine the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions; Overpressure protection is provided for the main steam system according to the capacity configuration information of the overpressure relief equipment.

2. The method according to claim 1, characterized in that In the process of using different overpressure protection strategies for the main steam system, determining the preset working condition for triggering overpressure protection of the main steam system according to the pressure rise of the main steam system specifically includes: In the process of using different overpressure protection strategies for the main steam system, the first operating condition for triggering overpressure protection of the main steam system is determined from the direction of core heat generation according to the pressure rise of the main steam system; In the process of using different overpressure protection strategies for the main steam system, the second operating condition of the main steam system triggering overpressure protection is determined from the steam discharge direction according to the pressure rise of the main steam system; The first operating condition and the second operating condition are combined to determine a preset operating condition for triggering overpressure protection of the main steam system.

3. The method according to claim 2, characterized in that In the process of using different overpressure protection strategies for the main steam system, determining the first operating condition for triggering overpressure protection of the main steam system from the direction of core heat generation according to the pressure rise of the main steam system specifically includes: When using different overpressure protection strategies in the main steam system, the influence of different control rod withdrawal rates on the pressure rise of the main steam system is evaluated; According to the evaluation results of the impact of the pressure rise in the main steam system, the control rod withdrawal situation with the largest pressure rise in the main steam system is determined as the first operating condition for triggering overpressure protection of the main steam system.

4. The method according to claim 2, characterized in that: In the process of using different overpressure protection strategies for the main steam system, determining the second operating condition for triggering overpressure protection of the main steam system from the steam discharge direction according to the pressure rise of the main steam system specifically includes: When using different overpressure protection strategies for the main steam system, select valves with closing functions on the normal discharge path of the main steam system; Evaluate the pressure increase of the main steam system caused by the closing of different valves, and determine the closing moment of the valve with the largest pressure increase in the main steam system as the second operating condition for triggering overpressure protection of the main steam system.

5. The method according to claim 1, characterized in that Determining the acceptance criteria of the preset working condition according to the classification corresponding to the preset working condition specifically includes: Classify the preset working conditions from the perspective of probability of occurrence to obtain the classification of the preset working conditions; On the basis of ensuring that the indicators of the main steam system during the accident process meet the design requirements, corresponding acceptance criteria are selected according to the classification of the preset working conditions to obtain the acceptance criteria of the preset working conditions.

6. The method according to any one of claims 1 to 5, characterized in that In the process of using different overpressure protection strategies for the main steam system, after determining the preset working condition for triggering overpressure protection of the main steam system according to the pressure rise of the main steam system, the method further includes: According to the preset operating conditions, a short-term overpressure accident that poses a risk to the main steam pressure boundary is determined, and a shutdown protection signal is set according to the pressure rise caused by the development of the short-term overpressure accident. The shutdown protection signal is triggered when any of the following scenarios is met: the pressurizer pressure reaches a first preset threshold, the main steam system pressure reaches a second preset threshold, the core nuclear power reaches a third preset threshold, and the turbine shutdown and condenser discharge failure are met.

7. The method according to any one of claims 1 to 5, characterized in that The determination of the capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working conditions on the basis of satisfying the acceptance criteria specifically includes: Obtain the valve characteristics of the safety valve of the main steam system during overpressure discharge; Analyzing the preset operating condition at the design pressure according to the valve characteristics of the safety valve to determine the minimum valve displacement required to meet the acceptance criteria under a given shutdown protection signal; Based on the set valve opening pressure and the valve displacement corresponding to the pressure, the preset working condition is evaluated; If the evaluation result does not meet the acceptance criteria, the valve displacement is increased until the evaluation result meets the acceptance criteria, and the valve displacement determined to meet the acceptance criteria is used as the minimum valve displacement; According to the minimum displacement of the valve, the minimum value between the empirical maximum displacement of the valve and the set maximum displacement of the valve is selected as the maximum displacement of the valve, the empirical maximum displacement of the valve is calculated based on the ratio of the maximum displacement of the valve to the minimum displacement of the valve not exceeding the preset value, and the set maximum displacement of the valve is the maximum displacement of the valve acceptable to the set working condition obtained by selecting the event working condition evaluation, and the event working condition includes the single valve mistakenly opened and the single valve stuck open; According to the valve opening pressure, the maximum displacement of the valve and the minimum displacement of the valve, the capacity configuration information of the overpressure relief equipment of the main steam system under the preset working conditions is determined.

8. An overpressure protection device for a main steam system, characterized in that: include: An acquisition unit, used to acquire the overpressure protection strategy triggered by the main steam system when the nuclear power plant is in different abnormal operating conditions; A first determination unit is used to determine a preset working condition for triggering overpressure protection of the main steam system according to a pressure rise of the main steam system during the process of using different overpressure protection strategies of the main steam system; A second determination unit, configured to determine an acceptance criterion for a preset working condition according to a classification corresponding to the preset working condition; A third determination unit is used to determine the capacity configuration information of the overpressure discharge equipment of the main steam system under the preset working conditions on the basis of satisfying the acceptance criteria; The overpressure protection unit is used to provide overpressure protection for the main steam system according to the capacity configuration information of the overpressure discharge equipment.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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