Performance test method and system for nuclear reactor coolant pump

Abstract

The embodiment of the invention discloses a performance test method and system for a nuclear reactor coolant pump, and relates to the technical field of nuclear reactors, and the method comprises the steps: obtaining a first measurement value sequence of a main pump in a nuclear reactor in a power-off state, and a second measurement value of the main pump in a power-off instant state, the first measurement value sequence comprises a plurality of first measurement values; determining an initial descent curve of the coolant flow in the loop according to the first measured value sequence and the second measured value; determining a target descent curve according to the initial descent curve and the coolant steady-state flow of each coolant loop in the loop of the nuclear reactor working under different powers; according to the target descent curve, the first preset running-down flow curve and the second preset running-down flow curve, whether the performance test result of the main pump meets the safety analysis requirement or not is determined, and the accuracy of the running-down performance test of the main pump can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear reactors, and particularly relates to a performance test method and system for a nuclear reactor coolant pump. BACKGROUND

[0002] The coolant pump in a nuclear reactor is a key device for ensuring the circulation of the reactor core coolant, and the coastdown performance of the coolant pump directly affects the ability of the reactor core to discharge residual heat after shutdown. However, the coastdown test acceptance criteria and acceptance strategies in the related art are not comprehensive for testing the coastdown performance of the coolant pump, which leads to low accuracy of the coastdown performance test of the coolant pump and the inability to reflect whether the actual coastdown performance of the coolant pump meets the requirements of safety analysis.

[0003] CONTENT

[0004] Therefore, one of the purposes of the present application is to provide a performance test method and system for a nuclear reactor coolant pump, which can improve the accuracy of the coastdown performance test of the main pump.

[0005] To achieve the above-mentioned purposes, the technical solution of the present application is as follows:

[0006] In a first aspect, the embodiments of the present application provide a performance test method for a nuclear reactor coolant pump, which comprises:

[0007] obtaining a first measurement value sequence of the main pump in a nuclear reactor under a power-off state and a second measurement value of the main pump under a power-off instant state, the first measurement value sequence comprising a plurality of first measurement values, and the main pump being a coolant pump in the nuclear reactor;

[0008] determining an initial decline curve of the coolant flow in the primary loop according to the first measurement value sequence and the second measurement value;

[0009] determining a target decline curve according to the initial decline curve and the coolant steady-state flow of each coolant loop in the primary loop of the nuclear reactor under different power;

[0010] determining a performance test result of the main pump according to the target decline curve, a first preset coastdown flow curve and a second preset coastdown flow curve, the first preset coastdown flow curve and the second preset coastdown flow curve being obtained based on a preset safety analysis result, and the first preset coastdown flow curve and the second preset coastdown flow curve being used to indicate whether the performance test result meets the safety analysis requirement.

[0011] In a possible implementation, the first measurement value is a measurement value of the coolant flow in the primary loop under the power-off state, and the second measurement value is a measurement value of the coolant flow in the primary loop under the power-off instant state.

[0012] Alternatively, the first measurement value is a measurement value of the rotating speed of the main pump in a power-off state, and the second measurement value is a measurement value of the rotating speed of the main pump in a power-off instant state.

[0013] In a possible implementation, the initial descending curve includes a sub-descending curve corresponding to each coolant loop in the primary loop.

[0014] According to the initial descending curve and the coolant steady flow of each coolant loop in the primary loop under different power operations of the nuclear reactor, the target descending curve is determined, including:

[0015] According to the heat balance method, the absolute value of the coolant steady flow of each coolant loop and the flow uncertainty value are determined.

[0016] According to the sub-descending curve corresponding to each coolant loop, the coolant steady flow, the flow uncertainty value, and the design flow of the nuclear reactor, the target descending curve is determined.

[0017] In a possible implementation, after the initial descending curve of the coolant flow in the primary loop is determined according to the first measurement value sequence and the second measurement value, the method further includes:

[0018] The response time of a detector in the nuclear reactor is obtained.

[0019] The initial descending curve is updated according to the response time of the detector, to obtain an updated initial descending curve.

[0020] According to the initial descending curve and the coolant steady flow of each coolant loop in the primary loop under different power operations of the nuclear reactor, the target descending curve is determined, including:

[0021] According to the updated initial descending curve and the coolant steady flow of each coolant loop in the primary loop under different power operations of the nuclear reactor, the target descending curve is determined.

[0022] In a possible implementation, the target descending curve includes a first target descending curve, and the design flow includes a thermal design flow.

[0023] According to the sub-descending curve corresponding to each coolant loop, the coolant steady flow, the flow uncertainty value, and the design flow of the nuclear reactor, the target descending curve is determined, including:

[0024] For each coolant loop in all coolant loops, the sub-descending curve corresponding to the coolant loop is updated according to the coolant steady flow corresponding to the coolant loop, to obtain a plurality of intermediate descending curves corresponding to all coolant loops, and the coolant loop and the intermediate descending curve correspond to each other.

[0025] According to the plurality of intermediate descent curves, the flow uncertainty value, and the design flow rate, a first target descent curve is determined.

[0026] In a possible implementation, the target descent curve includes a second target descent curve, and the design flow rate includes a mechanical design flow rate.

[0027] According to the plurality of intermediate descent curves, the flow uncertainty value, and the design flow rate, a first target descent curve is determined.

[0028] For each of the plurality of coolant loops, according to the coolant steady-state flow rate corresponding to the coolant loop, the sub-descent curve corresponding to the coolant loop is updated to obtain a plurality of intermediate descent curves corresponding to the plurality of coolant loops, the coolant loop and the intermediate descent curve corresponding to the coolant loop in one-to-one correspondence.

[0029] According to the plurality of intermediate descent curves, the flow uncertainty value, and the mechanical design flow rate, a second target descent curve is determined.

[0030] In a possible implementation, the performance test result of the main pump is determined according to the target descent curve, a first preset coast-down flow rate curve, and a second preset coast-down flow rate curve, including:

[0031] If the value of the first target descent curve is greater than the value corresponding to the first preset coast-down flow rate curve, and the value of the second target descent curve is less than the value corresponding to the second preset coast-down flow rate curve at the same time node, it is determined that the performance test result is qualified.

[0032] In a possible implementation, before the performance test result of the main pump is determined according to the target descent curve, the first preset coast-down flow rate curve, and the second preset coast-down flow rate curve, the method further includes:

[0033] A first assumed uncertainty parameter range corresponding to the moment of inertia of the main pump is obtained.

[0034] Based on the first assumed uncertainty parameter range, probabilistic safety analysis and thermal-hydraulic simulation are performed on a shutdown condition of the main pump to determine a plurality of transient events corresponding to the design reference condition of the nuclear reactor, a frequency of occurrence of each transient event, and a deviation from nucleate boiling risk value corresponding to each transient event, the shutdown condition being a condition corresponding to a state of the main pump after power failure;

[0035] According to the frequency of occurrence of each transient event and the deviation from nucleate boiling risk value corresponding to each transient event, a first target transient event is determined from the plurality of transient events, the condition corresponding to the first target transient event being a first target condition.

[0036] In a case where the deviated nucleate boiling risk value corresponding to the first target working condition is greater than a first preset safety threshold, a first initial uncertainty parameter range is determined;

[0037] Based on the first initial uncertainty parameter range, a working condition simulation is performed on the first preset working condition to obtain a first target uncertainty parameter range;

[0038] Based on the first target uncertainty parameter range, a simulation is performed on the first target working condition to obtain a first preset coast-down flow curve.

[0039] In a possible implementation, before the performance test result of the main pump is determined according to the target drop curve, the first preset coast-down flow curve and the second preset coast-down flow curve, the method further includes:

[0040] A second assumed uncertainty parameter range corresponding to the moment of inertia of the main pump is obtained;

[0041] Based on the second assumed uncertainty parameter range, a probabilistic safety analysis and thermal-hydraulic simulation are performed on a shutdown working condition of the main pump to determine a plurality of transient events corresponding to a load working condition in the nuclear reactor, occurrence frequencies of the transient events, and overpressure risk values corresponding to the transient events, the shutdown working condition being a working condition corresponding to a state of the main pump after power failure;

[0042] According to the occurrence frequencies of the transient events and the overpressure risk values corresponding to the transient events, a second target transient event is determined from the plurality of transient events, a working condition corresponding to the second target transient event being a second target working condition;

[0043] In a case where the overpressure risk value corresponding to the second target working condition is less than a second preset safety threshold, a second initial uncertainty parameter range is determined;

[0044] Based on the second initial uncertainty parameter range, a simulation is performed on the second preset working condition to obtain a second target uncertainty parameter range;

[0045] Based on the second target uncertainty parameter range, a simulation is performed on the second target working condition to obtain a second preset coast-down flow curve.

[0046] In a second aspect, an embodiment of the present application provides a performance test system of a nuclear reactor coolant pump, which comprises:

[0047] An acquisition module is configured to acquire a first measurement value sequence of a main pump in a state after power failure in a nuclear reactor and a second measurement value of the main pump in a state at a power failure moment, the first measurement value sequence comprising a plurality of first measurement values, and the main pump being a coolant pump in the nuclear reactor;

[0048] A first determination module is configured to determine an initial drop curve of coolant flow in a primary loop according to the first measurement value sequence and the second measurement value.

[0049] a second determining module configured to determine a target descent curve according to the initial descent curve and coolant steady-state flow rates of each coolant loop in the primary loop of the nuclear reactor at different power operations;

[0050] a third determining module configured to determine a performance test result of the main pump according to the target descent curve, a first preset coast-down flow rate curve and a second preset coast-down flow rate curve, the first preset coast-down flow rate curve and the second preset coast-down flow rate curve being obtained based on a preset safety analysis result, and the first preset coast-down flow rate curve and the second preset coast-down flow rate curve being used to indicate whether the performance test result meets the safety analysis requirement.

[0051] The performance test method of the nuclear reactor coolant pump provided by the embodiment of the present application can obtain a first measurement value sequence of the main pump in the nuclear reactor in a state after power failure and a second measurement value of the main pump in a state at the moment of power failure, and then determine an initial descent curve of coolant flow rate in the primary loop. Subsequently, a target descent curve can be determined according to the initial descent curve and coolant steady-state flow rates of each coolant loop in the primary loop of the nuclear reactor at different power operations. Finally, whether the performance test result of the main pump meets the safety analysis requirement can be determined according to the target descent curve, the first preset coast-down flow rate curve and the second preset coast-down flow rate curve, so that the accuracy of the coast-down performance test of the main pump can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. It should be understood that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0053] Figure 1 A flowchart of a performance test method of a nuclear reactor coolant pump provided by an embodiment of the present application;

[0054] Figure 2 A preset coast-down flow rate curve determination flowchart included in a performance test method of a nuclear reactor coolant pump provided by an embodiment of the present application;

[0055] Figure 3 A comparison schematic diagram related to a performance test method of a nuclear reactor coolant pump provided by an embodiment of the present application;

[0056] Figure 4 Another comparison schematic diagram related to a performance test method of a nuclear reactor coolant pump provided by an embodiment of the present application;

[0057] Figure 5A functional module schematic diagram of a performance test system of a nuclear reactor coolant pump provided by an embodiment of the present application is shown in FIG. 5.

[0058] Figure 6 An internal structure diagram of an electronic device provided by an embodiment of the present application is shown in FIG. 6.

[0059] Label explanation:

[0060] 500, a performance test system of a nuclear reactor coolant pump;

[0061] 510, an acquisition module;

[0062] 520, a first determination module;

[0063] 530, a second determination module;

[0064] 540, a third determination module. DETAILED DESCRIPTION

[0065] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0066] Therefore, the detailed description of the embodiments of the present application provided in the drawings below is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0067] It should be noted that: similar labels and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0068] In various embodiments of the present application, the expression "or" or "at least one of A or / and B" includes any combination or all combinations of the listed terms. For example, the expression "A or B" or "at least one of A or / and B" can include A, can include B, or can include both A and B.

[0069] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship of the product in use, only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0070] In addition, if the terms "first", "second" and the like appear, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0071] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0072] Also, in the embodiments of the present application, the term "connection" can mean "electrical connection", and can also mean "direct connection". "Electrical connection" can mean that two components are directly electrically connected, or that two components are electrically connected via one or more other components such as normally open tubes.

[0073] In order to better understand the scheme of the embodiments of the present application, first, the related art and the corresponding background art will be introduced.

[0074] A primary loop of a nuclear reactor includes a plurality of loops, each of which is provided with a coolant pump, hereinafter referred to as "main pump", which can be used to drive the coolant to circulate in the reactor coolant system (RCP) to continuously transfer the heat generated in the core to the secondary side feedwater of the steam generator. The main pump needs to ensure that an appropriate amount of coolant flows through the core to maintain the departure from nucleate boiling ratio (DNBR) greater than the designed allowable value. In the event of a power failure of the main pump, the nuclear reactor is shut down. After shutdown, the residual power of the nuclear reactor decreases exponentially, so a relatively high coolant flow through the core of the nuclear reactor needs to be maintained in a short time.

[0075] The main pump is provided with a heavy inertia flywheel fixed at the shaft end of the motor in the nuclear reactor, which can increase the rotational inertia of the main pump and prolong the inertia time of the pump. The applicant found through research that, in the case of inertia rotation of the main pump after power failure, if the primary coolant drops too quickly, the residual heat of the core cannot be taken out by the coolant, which is easy to cause the fuel rod cladding surface to deviate from nucleate boiling (Departure from Nucleate Boiling, DNB), thereby burning the fuel cladding and damaging the first safety barrier of the nuclear reactor. If the primary coolant drops too slowly, the “low main pump speed” or “low reactor coolant flow” shutdown signal is reached late, and the core is at a high power level for a long time, which is easy to cause the primary system to overpressure. At the same time, the heat of the core at a high power level is transmitted to the secondary circuit, which may cause the secondary system to overpressure.

[0076] The inertia test of the main pump can verify whether the decay of the coolant flow in the primary loop meets the safety analysis requirements during the hot shutdown of the pre-critical period and when part or all of the main pumps are shut down at the same time. The corresponding test acceptance criteria can be referred to as safety criteria. As described above, too fast a drop in the primary coolant is easy to cause DNB, and too slow a drop in the primary coolant is easy to cause overpressure in the primary loop, so the inertia test of the main pump is needed to ensure that the primary coolant flow meets the fast decay criterion and the slow decay criterion, and to avoid DNB in the core and overpressure in the primary system and the secondary system.

[0077] The primary loop system generally refers to the RCP. The RCP, also known as the primary loop system, is the reactor coolant system in the nuclear power plant system.

[0078] The secondary loop system, also referred to as the steam and energy conversion system, is a secondary coolant circulation system in the nuclear power plant that receives the heat of the core taken out by the reactor coolant and utilizes it (generates power or supplies heat).

[0079] In order to improve the accuracy of the inertia performance test of the main pump, the embodiments of the present application provide a performance test method of a nuclear reactor coolant pump, a performance test system of a nuclear reactor coolant pump, an electronic device, a computer readable storage medium and a computer program product. First, the performance test method of the nuclear reactor coolant pump provided by the embodiments of the present application will be introduced.

[0080] Please refer to Figure 1 , Figure 1 The flowchart of the performance test method of the nuclear reactor coolant pump provided by the embodiments of the present application. The performance test method of the nuclear reactor coolant pump can be applied to the performance test system of the nuclear reactor coolant pump in the following embodiments or the electronic device, wherein the electronic device includes personal computers, servers, mobile devices, cloud computing platforms and supercomputers, etc.

[0081] The performance test method of the nuclear reactor coolant pump will be introduced below, which specifically includes the following steps:

[0082] In step 110, a first measurement value sequence of the main pump in a state after power failure and a second measurement value of the main pump in a state at the moment of power failure are obtained, the first measurement value sequence includes a plurality of first measurement values, and the main pump is a coolant pump in the nuclear reactor.

[0083] In step 120, an initial drop curve of coolant flow in the primary loop is determined according to the first measurement value sequence and the second measurement value.

[0084] In step 130, a target drop curve is determined according to the initial drop curve and coolant steady-state flow of each coolant loop in the primary loop of the nuclear reactor under different power operations.

[0085] In step 140, a performance test result of the main pump is determined according to the target drop curve, a first preset coast-down flow curve and a second preset coast-down flow curve, the first preset coast-down flow curve and the second preset coast-down flow curve are obtained based on a preset safety analysis result, and the first preset coast-down flow curve and the second preset coast-down flow curve are used to indicate whether the performance test result meets the safety analysis requirement.

[0086] The performance test method of the nuclear reactor coolant pump provided by the embodiment can obtain a first measurement value sequence of the main pump in a state after power failure and a second measurement value of the main pump in a state at the moment of power failure, and then determine an initial drop curve of coolant flow in the primary loop. Subsequently, a target drop curve can be determined according to the initial drop curve and coolant steady-state flow of each coolant loop in the primary loop of the nuclear reactor under different power operations. Finally, whether the performance test result of the main pump meets the safety analysis requirement can be determined according to the target drop curve, a first preset coast-down flow curve and a second preset coast-down flow curve, which can improve the accuracy of the coast-down performance test of the main pump.

[0087] The various steps of the method will be described in detail below. Figure 1

[0088] In step 110, the electronic device can obtain a first measurement value sequence of the main pump in a state after power failure and a second measurement value of the main pump in a state at the moment of power failure, and the first measurement value sequence and the second measurement value can be used to determine a target drop curve in the following embodiments.

[0089] The first measurement value sequence can be used to represent the change of coolant flow in the primary loop with time in the power failure state of the main pump.

[0090] The second measurement value can be used to represent the coolant flow in the primary loop in the state at the moment of power failure of the main pump.​

[0091] According to the centrifugal pump similarity law, for the same main pump, the ratio of the coolant flow rate in the loop is proportional to the ratio of the rotation speed of the main pump. In a possible implementation, the first measurement value is the measurement value of the coolant flow rate in the loop in the post-power-off state, and the second measurement value is the measurement value of the coolant flow rate in the loop in the power-off instant state;

[0092] Alternatively, the first measurement value is the rotation speed measurement value of the main pump in the post-power-off state, and the second measurement value is the rotation speed measurement value of the main pump in the power-off instant state.

[0093] If t=0 represents the power-off instant state, the post-power-off state can be represented by t>0, and t in this embodiment can represent the power-off time.

[0094] In step 120, after obtaining the first measurement value sequence and the second measurement value, the electronic device can further determine an initial drop curve of the coolant flow rate in the loop.

[0095] The initial drop curve can be used to represent the change curve of the coolant flow rate in the loop within a time period under the condition that the main pump is powered off, for example, the initial drop curve can include the change curve of the coolant flow rate in the loop within 20s after the main pump is powered off, the horizontal axis of the initial drop curve can represent time such as 1s to 20s, and the vertical axis of the initial drop curve can represent the coolant flow rate proportion.

[0096] In some embodiments, if the first measurement value sequence includes 20 measurement values of the coolant flow rate in the loop within 20s after the main pump is powered off, and the second measurement value includes the measurement value of the coolant flow rate in the loop in the power-off instant state, the 20 measurement values of the coolant flow rate in the loop within 20s after the main pump is powered off can be sequentially divided by the measurement value of the coolant flow rate in the loop in the power-off instant state according to the time node, to obtain the drop curve of the coolant flow rate in the main pump within 20s after the main pump is powered off, that is, the initial drop curve.

[0097] Taking one of the loops in the loop as an example, the first measurement value sequence includes 20 measurement values of the coolant flow rate in the loop in which the main pump is located within 20s after the main pump is powered off q i (1),q i (2),…,q i (20) ], i represents the loop number in which the main pump is located. The second measurement value is the measurement value q i (0) of the coolant flow rate in the loop in the power-off instant state, and i also represents the loop number in which the main pump is located. Accordingly, according to q i (1) / q i (0), …, qi (20) / q i (0), 20 calculation values can be determined, and based on the 20 calculation values, the decline curve of the coolant flow in the i loop of the main pump within 20s after the power-off can be determined.

[0098] In some embodiments, if the first sequence of measurement values includes 20 rotation speed measurement values of the main pump within 20s after the power-off, and the second measurement value is the rotation speed measurement value of the main pump in the power-off instant state, the 20 rotation speed measurement values of the main pump within 20s after the power-off can be sequentially divided by the rotation speed measurement value of the main pump in the power-off instant state according to the time nodes, to obtain the decline curve of the coolant flow of the main pump within 20s after the power-off, that is, the initial decline curve described above.

[0099] In combination with the above example, if the first sequence of measurement values and the second measurement value are both rotation speed measurement values, similarly, the 20 rotation speed measurement values [RPM i (1), RPM i (2), …, RPM i (20)] in the power-off state, and the rotation speed measurement value RPM i (0) in the power-off instant state. Accordingly, according to RPM i (1) / RPM i (0), …, RPM i (20) / RPM i (0), 20 calculation values can be determined, and based on the 20 calculation values, the decline curve of the coolant flow in the i loop of the main pump within 20s after the power-off can be determined.

[0100] The decline curve of the coolant flow in the i loop of the above-mentioned loop α i (t) can be represented as follows, t represents time:

[0101]

[0102] In some embodiments, after the electronic device determines the decline curves of the coolant flows in the loops in the loop, the electronic device can determine the initial decline curve of the coolant flow in the loop according to the decline curves of the coolant flows in all the loops in the loop. For example, the loop includes 3 loops, and the corresponding decline curves of the coolant flows are α1(t), α2(t) and α3(t), and the initial decline curve α(t) of the coolant flow in the loop can be determined according to α1(t), α2(t) and α3(t).

[0103] In step 130, after the electronic device determines the initial decline curve of the coolant in the loop according to the above-mentioned embodiments, the electronic device can further determine the target decline curve in combination with the steady-state coolant flows of the coolant loops in the loop under different power of the nuclear reactor.

[0104] The coolant steady-state flow rate can represent the flow rate of the coolant in each loop of the loop system in a stable operation state. The coolant steady-state flow rate is an important parameter for the operation of the nuclear reactor. By monitoring the coolant steady-state flow rate in real time, it can be determined whether an abnormal situation occurs during the operation of the nuclear reactor.

[0105] For example, the coolant steady-state flow rate can be represented by Q ij , where i represents the number of the loop, and j represents the power platform, and different values of j correspond to different power levels.

[0106] The electronic device determines the target drop curve based on the initial drop curve a(t) including a1(t), a2(t), and a3(t) and the absolute values of the coolant steady-state flow rates Q ij ( e.g., Q 1j , Q 2j , and Q 3j ) of the coolant in each loop.

[0107] In some embodiments, the electronic device can multiply each value in the drop curve a1(t) of the coolant in loop 1 in the loop by Q 1j to update the drop curve of the coolant, and after the drop curves of the coolants in all loops are updated, the target drop curve can be determined based on the updated drop curves of the coolants in all loops.

[0108] Multiplying each value in the drop curve a1(t) of the coolant in loop 1 by Q 1j , the absolute value of the flow rate of the coolant at each time in the drop curve of the coolant in loop 1 can be obtained. Using the absolute value of the flow rate of the coolant can improve the accuracy and reliability of the determined target drop curve, and thus the accuracy and reliability of the performance test of the main pump.

[0109] In step 140, the electronic device can compare the target drop curve obtained in the above embodiments with the first preset drop curve and the second preset drop curve, and thus the performance test result of the main pump can be determined.

[0110] The first preset drop curve and the second preset drop curve correspond to the fast decay criterion and the slow decay criterion, respectively. That is, the first preset drop curve can be regarded as the fast decay criterion, and the second preset drop curve can be regarded as the slow decay criterion.

[0111] The target drop curve can be regarded as the drop curve of the flow rate of the coolant in the loop during the actual outage of the main pump.

[0112] Specifically, the electronic device can determine whether the DNBR of the reactor system exceeds the limit value after the main pump is powered off according to the first target drop curve and the first preset coast-down flow curve.

[0113] The electronic device can determine whether the primary loop system and the secondary loop system will appear overpressure after the main pump is powered off according to the second target drop curve and the second preset coast-down curve.

[0114] The electronic device can determine that the coast-down performance of the main pump is qualified according to the first target drop curve being higher than the first preset coast-down flow curve and the second target drop curve being lower than the second preset coast-down flow curve, and otherwise, the electronic device can determine that the coast-down performance of the main pump is unqualified.

[0115] In a possible implementation, after the initial drop curve of the coolant flow in the primary loop is determined according to the first sequence of measurement values and the second measurement value, the method further includes:

[0116] obtaining a detector response time in the nuclear reactor;

[0117] updating the initial drop curve according to the detector response time to obtain an updated initial drop curve;

[0118] determining a target drop curve according to the initial drop curve and the steady-state flow of the coolant in each coolant loop in the primary loop of the nuclear reactor under different power operations, including:

[0119] determining the target drop curve according to the updated initial drop curve and the steady-state flow of the coolant in each coolant loop in the primary loop of the nuclear reactor under different power operations.

[0120] The embodiments of the present application can further improve the accuracy and reliability of the determined target drop curve by considering the hysteresis of the detector response time and updating the initial drop curve according to the detector response time.

[0121] Exemplarily, the updated initial drop curve α'(t) can be represented as follows:

[0122] α i ′(t)=α i (t+τ) (2);

[0123] wherein, α i ′(0)=α i (0)=1, and τ represents the detector response time.

[0124] Correspondingly, in the case of three loops, the updated initial drop curve α'(t) includes the following sub-drop curves α1'(t), α2'(t) and α3'(t) corresponding to the three loops.

[0125] In a possible implementation, the initial descending curve includes a sub-descending curve corresponding to each coolant loop in the primary loop;

[0126] According to the initial descending curve and the coolant steady flow of each coolant loop in the primary loop under different power of the nuclear reactor, the target descending curve is determined, including:

[0127] According to the heat balance method, the absolute value of the coolant steady flow of each coolant loop and the flow uncertainty value are determined;

[0128] According to the sub-descending curve corresponding to each coolant loop, the coolant steady flow, the flow uncertainty value, and the design flow of the nuclear reactor, the target descending curve is determined.

[0129] The embodiments of the present application can further improve the test reliability of the idling performance test of the main pump by determining the flow uncertainty value corresponding to the steady flow of each loop and participating in the determination process of the target descending curve.

[0130] The initial descending curve includes a sub-descending curve corresponding to each coolant loop (i.e., each loop) in the primary loop. For details, refer to the foregoing embodiments. For example, the primary loop includes three loops as shown in the foregoing embodiments, and the sub-descending curves corresponding to the three loops are α1(t), α2(t), and α3(t).

[0131] The coolant steady flow can refer to the foregoing embodiments, and details are not repeated here.

[0132] The flow uncertainty value refers to the error range that cannot be ignored due to measurement error, system complexity, and other factors when calculating the coolant steady flow. In some embodiments, the electronic device can determine the flow uncertainty value based on the measurement parameters of the nuclear reactor.

[0133] The heat balance method is based on the law of conservation of energy (the heat released by the core plus the heat generated by the main pump is equal to the heat taken away by the secondary loop). For details of determining the absolute value of the coolant steady flow of each coolant loop and the flow uncertainty value according to the heat balance method, refer to related technologies, and details are not repeated here.

[0134] In some embodiments, the electronic device can determine the flow uncertainty value of each loop when the main pump of each loop is idling according to the updated sub-descending curve of each loop and the coolant steady flow and the flow uncertainty value of each loop.

[0135] Taking the updated sub-descending curve α i ′(t) of the i-th loop as an example, the flow uncertainty value ΔQ ej of the j-th power platform can be represented as follows:

[0136]

[0137] wherein, AQ ij represents the flow uncertainty value of the i-loop j power platform (which can actually refer to the steady-state flow measurement uncertainty value).

[0138] Based on the above formula, the total flow uncertainty value of all loops in the primary pump idle loop can be determined.

[0139] In some embodiments, the target descent curve is determined according to the corresponding sub-descent curve of each coolant loop, the steady-state flow of the coolant, the flow uncertainty value, and the design flow of the nuclear reactor, comprising:

[0140] The target descent curve is determined according to the updated sub-descent curve of each coolant loop, the steady-state flow of the coolant, the flow uncertainty value, and the design flow of the nuclear reactor.

[0141] Exemplarily, the target descent curve α''(t) can be represented as follows:

[0142]

[0143] wherein, Q represents the design flow.

[0144] In one possible implementation, the target descent curve includes a first target descent curve, and the design flow includes a thermal design flow;

[0145] The target descent curve is determined according to the corresponding sub-descent curve of each coolant loop, the steady-state flow of the coolant, the flow uncertainty value, and the design flow of the nuclear reactor, comprising:

[0146] For each of all coolant loops, the sub-descent curve corresponding to the coolant loop is updated according to the steady-state flow of the coolant corresponding to the coolant loop, to obtain a plurality of intermediate descent curves corresponding to all coolant loops, the coolant loop and the intermediate descent curve corresponding one-to-one;

[0147] The first target descent curve is determined according to all intermediate descent curves, the flow uncertainty value, and the thermal design flow.

[0148] As described above, the first target descent curve α''1(t) can be obtained by updating formula (4) in the above embodiments, and is represented as follows:

[0149]

[0150] wherein, Q TH represents the above thermal design flow.

[0151] In a possible implementation, the target decrease curve includes a second target decrease curve, and the design flow rate includes a mechanical design flow rate.

[0152] The target decrease curve is determined according to the sub-decrease curve corresponding to each coolant loop, the coolant steady-state flow rate, the flow rate uncertainty value, and the design flow rate of the nuclear reactor, and includes:

[0153] For each of the coolant loops in all the coolant loops, the sub-decrease curve corresponding to the coolant loop is updated according to the coolant steady-state flow rate corresponding to the coolant loop, to obtain a plurality of intermediate decrease curves corresponding to all the coolant loops, the coolant loop and the intermediate decrease curve corresponding to each other;

[0154] The second target decrease curve is determined according to all the intermediate decrease curves, the flow rate uncertainty value, and the mechanical design flow rate.

[0155] As described above, the formula (4) in the above embodiment is updated to obtain the second target decrease curve α''2(t) as follows:

[0156]

[0157] Wherein, Q ME The mechanical design flow rate is indicated above.

[0158] In a possible implementation, before the performance test result of the main pump is determined according to the target decrease curve, the first preset coast-down flow rate curve, and the second preset coast-down flow rate curve, the method further includes:

[0159] A first assumed uncertainty parameter range corresponding to the moment of inertia of the main pump is obtained;

[0160] The off-site probabilistic safety analysis and thermal-hydraulic simulation are performed on the shutdown condition of the main pump based on the first assumed uncertainty parameter range, to determine a plurality of transient events corresponding to the design reference condition in the nuclear reactor, the occurrence frequency of each transient event, and the deviation from nucleate boiling risk value corresponding to each transient event, the shutdown condition being a condition corresponding to a state of the main pump after power failure;

[0161] The first target transient event is determined from the plurality of transient events according to the occurrence frequency of each transient event and the deviation from nucleate boiling risk value corresponding to each transient event, the condition corresponding to the first target transient event being a first target condition;

[0162] In a case where the deviation from nucleate boiling risk value corresponding to the first target condition is greater than a first preset safety threshold, a first initial uncertainty parameter range is determined;

[0163] The first target uncertainty parameter range is obtained by performing condition simulation on the first preset condition based on the first initial uncertainty parameter range.

[0164] simulate the first target working condition based on the first target uncertainty parameter range to obtain a first preset inertia flow curve.

[0165] In the case that the moment of inertia of the main pump and the first uncertainty parameter range thereof meet the first target working condition and the first preset working condition, the inertia flow curve simulated under the first target working condition can be used as the first preset inertia flow curve, and the first preset inertia flow curve can be used as the aforementioned attenuation criterion. Using the first preset inertia flow curve in the embodiment of the present application can improve the accuracy of determining whether the main pump meets the DNB requirement after power failure, and further improve the accuracy and comprehensiveness of testing the inertia performance of the main pump.

[0166] The moment of inertia refers to the theoretical moment of inertia value of the inertia flywheel of the main pump in the design stage, and the value provided by the manufacturer of the inertia flywheel can be used. The moment of inertia can determine the rate of flow attenuation of the main pump after power failure. Generally, the greater the moment of inertia, the longer the inertia time, and the slower the flow attenuation.

[0167] In some embodiments, the electronic device can determine the moment of inertia by the geometric size and material density of the inertia flywheel.

[0168] The first uncertainty parameter range can be used to represent the fluctuation interval allowed for the moment of inertia.

[0169] The probabilistic safety analysis and thermal hydraulic simulation can refer to the introduction of related technologies, which will not be described here.

[0170] The transient event can represent an event that can cause the main pump to be completely or partially shut down under the design basis condition of the nuclear power plant. For example, short-term loss of off-site power, etc.

[0171] The occurrence frequency can represent the probability density of the transient event occurring within the operating cycle of the nuclear power plant, and the unit is the number of occurrences per reactor year.

[0172] The departure from nucleate boiling risk value can be represented by the DNBR in the foregoing embodiments, which will not be described here.

[0173] The departure from nucleate boiling risk value corresponding to the first target working condition is greater than the first preset safety threshold (or greater than the first preset safety threshold with a certain margin), which can represent that the moment of inertia of the main pump and the corresponding first uncertainty parameter range can meet the DNB safety requirement. If it does not meet the requirement, the first uncertainty parameter range can be adjusted, and whether the DNB safety requirement is met can be determined based on the adjusted first uncertainty parameter range.

[0174] In the case that the DNB safety requirement is met and a certain margin is left (i.e., the deviation from the nucleate boiling risk value corresponding to the first target working condition is greater than the first preset safety threshold), it can be further verified whether the first uncertainty parameter range meets the DNB safety requirement of the first preset working condition. If not, the corresponding first uncertainty parameter range can be adjusted, and based on the adjusted first uncertainty parameter range, it is further judged whether the DNB safety requirement is met.

[0175] Based on the above-mentioned first preset working condition, if the DNB safety requirement is still met and a certain margin is left, the first preset coastdown flow curve of the primary loop can be obtained by simulating the coastdown of the main pump based on the first uncertainty parameter range and the first target working condition.

[0176] The above-mentioned first preset coastdown flow curve can be input to an electronic device as a judgment basis for test results.

[0177] In the embodiment of the present application, the simulation of the coastdown of the main pump based on the first uncertainty parameter range and the first target working condition is actually based on the lower limit value in the first uncertainty parameter range and the first target working condition.

[0178] In a possible implementation, before determining the performance test result of the main pump according to the target drop curve, the first preset coastdown flow curve and the second preset coastdown flow curve, the method further comprises:

[0179] Obtaining a second assumed uncertainty parameter range corresponding to the moment of inertia of the main pump;

[0180] Based on the second assumed uncertainty parameter range, the shutdown working condition of the main pump is subjected to probabilistic safety analysis and thermal-hydraulic simulation to determine a plurality of transient events corresponding to the load working condition in the nuclear reactor, the occurrence frequency of each transient event, and the overpressure risk value corresponding to each transient event. The shutdown working condition is the working condition corresponding to the state of the main pump after power failure;

[0181] According to the occurrence frequency of each transient event and the overpressure risk value corresponding to each transient event, a second target transient event is determined from the plurality of transient events, and the working condition corresponding to the second target transient event is a second target working condition;

[0182] In the case that the overpressure risk value corresponding to the second target working condition is less than a second preset safety threshold, a second initial uncertainty parameter range is determined;

[0183] Based on the second initial uncertainty parameter range, the second preset working condition is simulated to obtain a second target uncertainty parameter range;

[0184] Based on the second target uncertainty parameter range, the second target working condition is simulated to obtain a second preset coastdown flow curve.

[0185] In the case that the primary pump rotational inertia and the second uncertainty parameter range satisfy the second target working condition and the second preset working condition, the second target working condition can be used as the second preset idling flow curve, and the second preset idling flow curve can be used as the slow attenuation criterion. The second preset idling flow curve in the embodiment of the present application can improve the accuracy of the judgment of whether the primary pump will cause the overpressure of the primary loop and the secondary loop after power failure, and further improve the accuracy and comprehensiveness of the idling performance test of the primary pump.

[0186] In the embodiment of the present application, the idling of the primary pump is simulated based on the second uncertainty parameter range and the second target working condition. In fact, the idling of the primary pump is simulated based on the upper limit value in the second uncertainty parameter range and the second target working condition.

[0187] The second uncertainty parameter range can refer to the introduction of the first uncertainty parameter range in the foregoing embodiment.

[0188] The probabilistic safety analysis, the thermal-hydraulic simulation, the transient event, and the occurrence frequency can refer to the introduction in the foregoing embodiment.

[0189] The process of determining the second preset idling flow curve in the embodiment can refer to the introduction of determining the first preset idling flow curve in the foregoing embodiment, which will not be described herein.

[0190] The second preset working condition includes the overpressure consequence analysis of the primary pump full stop or partial stop pump working condition in the design reference working condition and the design extension working condition.

[0191] Please refer to Figure 2 , Figure 2 The preset idling flow curve determination flowchart of the performance test method of the nuclear reactor coolant pump provided in the embodiment of the present application.

[0192] In Figure 2 The left side of the determination of the fast attenuation criterion example is shown. The uncertainty assumption of the primary pump rotational inertia in the safety analysis is determined (corresponding to the first uncertainty parameter range of the primary pump rotational inertia). The constant volume working condition corresponds to the first target working condition. The primary pump full stop or partial stop pump working condition in the design extension working condition and the design reference working condition after the superimposed loss of off-site power (LOOP) assumption (that is, assuming that the accident occurs at the same time as the loss of off-site power) correspond to the first preset working condition.

[0193] In a possible implementation, according to the target drop curve, the first preset numerical curve, and the second preset numerical curve, the performance test result of the primary pump is determined, including:

[0194] If the value of the first target drop curve is greater than the value corresponding to the first preset value curve and the value of the second target drop curve is less than the value corresponding to the second preset value curve at the same time node, it is determined that the performance test result is qualified.

[0195] Please refer to Figure 3 and Figure 4 , wherein, Figure 3 is a comparison diagram involved in a performance test method of a nuclear reactor coolant pump provided by an embodiment of the present application. Figure 4 is another comparison diagram involved in a performance test method of a nuclear reactor coolant pump provided by an embodiment of the present application. Figure 3 and Figure 4 The vertical axis can represent the proportion of coolant flow, and the horizontal axis can represent time.

[0196] In Figure 3 , the dashed line can represent the second preset idle flow curve, and the straight line can represent the second target drop curve.

[0197] In Figure 4 , the dashed line can represent the first preset idle flow curve, and the straight line can represent the first target drop curve.

[0198] In combination with Figure 3 and Figure 4 It can be found that at the same time node, the idle flow of the first target drop curve is greater than the idle flow corresponding to the first preset idle flow curve, and the idle flow of the second target drop curve is less than the idle flow corresponding to the second preset idle flow curve, so it can be determined that the idle performance of the main pump is qualified.

[0199] Corresponding to the above method embodiment, the present embodiment also provides a performance test system of a nuclear reactor coolant pump, please refer to Figure 5 , Figure 5 is a functional module diagram of a performance test system of a nuclear reactor coolant pump provided by an embodiment of the present application, wherein the performance test system 500 of the nuclear reactor coolant pump comprises:

[0200] The acquisition module 510 is configured to acquire a first measurement value sequence of a main pump in a state after power failure in a nuclear reactor and a second measurement value of the main pump in a state at the moment of power failure, the first measurement value sequence comprises a plurality of first measurement values, and the main pump is a coolant pump in the nuclear reactor.

[0201] The first determination module 520 is configured to determine an initial drop curve of coolant flow in a primary loop according to the first measurement value sequence and the second measurement value.

[0202] The second determining module 530 is configured to determine a target descent curve according to the initial descent curve and the coolant steady-state flow of each coolant loop in the primary loop at different power operations of the nuclear reactor.

[0203] The third determining module 540 is configured to determine a performance test result of the main pump according to the target descent curve, a first preset idling flow curve and a second preset idling flow curve, the first preset idling flow curve and the second preset idling flow curve being obtained based on a preset safety analysis result, and the first preset idling flow curve and the second preset idling flow curve being used to indicate whether the performance test result meets the safety analysis requirement.

[0204] The performance test system of the nuclear reactor coolant pump provided by the embodiments of the present application can achieve the various processes of the method embodiments and achieve similar or the same technical effects. To avoid repetition, details are not described herein. Figure 1

[0205] In a possible implementation, the first measurement value is a measurement value of the coolant flow in the primary loop in a post-power-off state, and the second measurement value is a measurement value of the coolant flow in the primary loop in a power-off instant state.

[0206] Alternatively, the first measurement value is a measurement value of the rotating speed of the main pump in the post-power-off state, and the second measurement value is a measurement value of the rotating speed of the main pump in the power-off instant state.

[0207] In a possible implementation, the initial descent curve includes a plurality of sub-descent curves corresponding to the coolant loops in the primary loop.

[0208] The second determining module 530 is further configured to:

[0209] determine the absolute value of the coolant steady-state flow and the flow uncertainty value of each coolant loop according to the heat balance method;

[0210] determine the target descent curve according to the sub-descent curve corresponding to each coolant loop, the coolant steady-state flow, the flow uncertainty value, and the design flow of the nuclear reactor.

[0211] In a possible implementation, the target descent curve includes a first target descent curve, and the design flow includes a thermal design flow.

[0212] The second determining module 530 includes a first determining sub-module, which is configured to:

[0213] for each coolant loop in all the coolant loops, update the sub-descent curve corresponding to the coolant loop according to the coolant steady-state flow corresponding to the coolant loop, to obtain a plurality of intermediate descent curves corresponding to all the coolant loops, the coolant loop and the intermediate descent curve corresponding to each other. ​

[0214] determine the first target descent curve according to the all intermediate descent curves, the flow uncertainty value and the thermal design flow.

[0215] In a possible implementation, the target descent curve comprises a second target descent curve, and the design flow comprises a mechanical design flow.

[0216] The second determining module 530 comprises a second determining sub-module, which is configured to:

[0217] For each of the coolant loops, update the sub-descent curve corresponding to the coolant loop according to the coolant steady-state flow corresponding to the coolant loop, to obtain a plurality of intermediate descent curves corresponding to the all coolant loops, the coolant loop and the intermediate descent curve corresponding to each other;

[0218] determine the second target descent curve according to the all intermediate descent curves, the flow uncertainty value and the mechanical design flow.

[0219] In a possible implementation, the performance test system 500 of the nuclear reactor coolant pump further comprises an updating module, which is configured to:

[0220] obtain a detector response time in the nuclear reactor;

[0221] update the initial descent curve according to the detector response time, to obtain an updated initial descent curve;

[0222] The second determining module 530 is further configured to:

[0223] determine the target descent curve according to the updated initial descent curve and the coolant steady-state flow of each of the coolant loops in the primary loop of the nuclear reactor under different power operations.

[0224] In a possible implementation, the performance test system 500 of the nuclear reactor coolant pump further comprises a first analyzing module, which is configured to:

[0225] obtain a first assumed uncertainty parameter range corresponding to the moment of inertia of the main pump;

[0226] perform probabilistic safety analysis and thermal-hydraulic simulation on the outage condition of the main pump based on the first assumed uncertainty parameter range, to determine a plurality of transient events corresponding to the design reference condition in the nuclear reactor, the occurrence frequency of each transient event, and the deviation from nucleate boiling risk value corresponding to each transient event, the outage condition being a condition corresponding to the state of the main pump after power failure;

[0227] determine a first target transient event from the plurality of transient events according to the occurrence frequency of each transient event and the deviation from nucleate boiling risk value corresponding to each transient event, the working condition corresponding to the first target transient event being a first target working condition;

[0228] determine a first initial uncertainty parameter range in a case where the deviation from nucleate boiling risk value corresponding to the first target working condition is greater than a first preset safety threshold value;

[0229] perform working condition simulation on the first preset working condition based on the first initial uncertainty parameter range to obtain a first target uncertainty parameter range;

[0230] simulate the first target working condition based on the first target uncertainty parameter range to obtain a first preset coastdown flow curve.

[0231] In a possible implementation, the performance test system 500 of the nuclear reactor coolant pump further includes a second analysis module configured to:

[0232] obtain a second assumed uncertainty parameter range corresponding to the moment of inertia of the main pump;

[0233] perform probabilistic safety analysis and thermal-hydraulic simulation on the shutdown working condition of the main pump based on the second assumed uncertainty parameter range to determine a plurality of transient events corresponding to the load working condition of the nuclear reactor, the occurrence frequency of each transient event, and the overpressure risk value corresponding to each transient event, the shutdown working condition being a working condition corresponding to a state of the main pump after power failure;

[0234] determine a second target transient event from the plurality of transient events according to the occurrence frequency of each transient event and the overpressure risk value corresponding to each transient event, the working condition corresponding to the second target transient event being a second target working condition;

[0235] determine a second initial uncertainty parameter range in a case where the overpressure risk value corresponding to the second target working condition is less than a second preset safety threshold value;

[0236] simulate the second preset working condition based on the second initial uncertainty parameter range to obtain a second target uncertainty parameter range;

[0237] simulate the second target working condition based on the second target uncertainty parameter range to obtain a second preset coastdown flow curve.

[0238] In a possible implementation, the third determination module 540 is specifically configured to:

[0239] If the value of the first target falling curve is greater than the value corresponding to the first preset value curve and the value of the second target falling curve is less than the value corresponding to the second preset value curve at the same time node, it is determined that the performance test result is qualified.

[0240] The embodiment of the present application further provides an electronic device, and the present application further provides an electronic device, please refer to Figure 6 , Figure 6 An internal structure diagram of an electronic device provided by the embodiment of the present application is shown in the figure. The electronic device includes a processor, a memory and a network interface connected through a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the electronic device stores an operating system, and can also store a computer program. When the computer program is executed by the processor, the processor can implement the performance test method of the nuclear reactor coolant pump applied to the electronic device in the above embodiment. The internal memory can also store a computer program. When the computer program is executed by the processor, the processor can execute the performance test method of the nuclear reactor coolant pump. Those skilled in the art can understand that the structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the electronic device to which the scheme of the present application is applied. The specific electronic device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement. Figure 6

[0241] The embodiment of the present application further discloses a computer readable storage medium, and the computer readable storage medium stores a computer program. When the computer program is executed by the processor, the performance test method of the nuclear reactor coolant pump in the method embodiment is implemented.

[0242] The embodiment of the present application provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement each process of the embodiment of the performance test method of the nuclear reactor coolant pump, and can achieve similar or the same technical effects. To avoid repetition, details are not described here.

[0243] ​Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiment methods. Any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0244] The technical features of the above embodiments can be combined in any manner. In order to make the description simple, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present disclosure.

Claims

1. A performance testing method for a nuclear reactor coolant pump, characterized in that: The method comprises: Acquire a first measurement value sequence of a main pump in a nuclear reactor after power failure, and a second measurement value of the main pump at the moment of power failure, wherein the first measurement value sequence includes a plurality of first measurement values, and the main pump is a coolant pump in the nuclear reactor; determining an initial drop curve of the coolant flow in the primary circuit based on the first measurement value sequence and the second measurement value; determining a target descent curve based on the initial descent curve and the coolant steady-state flow rates of each coolant loop in the primary circuit when the nuclear reactor operates at different powers; The performance test result of the main pump is determined based on the target descent curve, the first preset idling flow curve and the second preset idling flow curve, the first preset idling flow curve and the second preset idling flow curve are obtained based on the preset safety analysis results, and the first preset idling flow curve and the second preset idling flow curve are used to indicate whether the performance test result meets the safety analysis requirements.

2. The method according to claim 1, characterized in that The first measurement value is a measurement value of the coolant flow rate in the primary circuit in the state after the power failure, and the second measurement value is a measurement value of the coolant flow rate in the primary circuit in the state at the moment of the power failure; Alternatively, the first measurement value is a rotational speed measurement value of the main pump in the state after the power failure, and the second measurement value is a rotational speed measurement value of the main pump in the state at the moment of the power failure.

3. The method according to claim 1, characterized in that The initial decline curve includes sub-decline curves corresponding to each coolant loop in the primary circuit; Determining a target descent curve based on the initial descent curve and the coolant steady-state flow rates of each coolant loop in the primary circuit when the nuclear reactor operates at different powers includes: Determining the absolute value of the coolant steady-state flow rate and the flow rate uncertainty value of each coolant loop according to the heat balance method; The target descent curve is determined according to the sub-descent curves corresponding to each coolant loop, the coolant steady-state flow rate, the flow rate uncertainty value, and the design flow rate of the nuclear reactor.

4. The method according to claim 3, characterized in that After determining an initial drop curve of the coolant flow rate in the primary circuit based on the first measurement value sequence and the second measurement value, the method further includes: Obtaining a detector response time in the nuclear reactor; updating the initial descent curve according to the detector response time to obtain an updated initial descent curve; Determining a target descent curve based on the initial descent curve and the coolant steady-state flow rates of each coolant loop in the primary circuit when the nuclear reactor operates at different powers includes: A target descent curve is determined according to the updated initial descent curve and the coolant steady-state flow rates of each coolant loop in the primary circuit when the nuclear reactor operates at different powers.

5. The method according to claim 3, characterized in that The target descent curve includes a first target descent curve, and the design flow rate includes a thermal design flow rate; Determining the target descent curve according to the sub-descent curves corresponding to each coolant loop, the coolant steady-state flow rate, the flow rate uncertainty value, and the design flow rate of the nuclear reactor includes: For each of the coolant loops in all the coolant loops, updating the sub-decline curve corresponding to the coolant loop according to the coolant steady-state flow rate corresponding to the coolant loop, thereby obtaining a plurality of intermediate decline curves corresponding to all the coolant loops, wherein the coolant loops correspond to the intermediate decline curves one-to-one; The first target descent curve is determined according to all the intermediate descent curves, the flow uncertainty value and the thermal design flow.

6. The method according to claim 5, characterized in that The target descent curve includes a second target descent curve, and the design flow rate includes a mechanical design flow rate; Determining the target descent curve according to the sub-descent curves corresponding to each coolant loop, the coolant steady-state flow rate, the flow rate uncertainty value, and the design flow rate of the nuclear reactor includes: For each of the coolant loops in all the coolant loops, updating the sub-decline curve corresponding to the coolant loop according to the coolant steady-state flow rate corresponding to the coolant loop, thereby obtaining a plurality of intermediate decline curves corresponding to all the coolant loops, wherein the coolant loops correspond to the intermediate decline curves one-to-one; The second target descent curve is determined according to all the intermediate descent curves, the flow uncertainty value and the mechanical design flow.

7. The method according to claim 6, characterized in that Determining the performance test result of the main pump according to the target descent curve, the first preset idling flow curve, and the second preset idling flow curve includes: If at the same time node, the value of the first target descent curve is greater than the value corresponding to the first preset idling flow curve, and the value of the second target descent curve is less than the value corresponding to the second preset idling flow curve, the performance test result is determined to be qualified.

8. The method according to claim 1, characterized in that Before determining the performance test result of the main pump according to the target descent curve, the first preset idling flow curve, and the second preset idling flow curve, the method further includes: Obtaining a first assumed uncertainty parameter range corresponding to the moment of inertia of the main pump; Based on the first assumed uncertainty parameter range, a probabilistic safety analysis and thermal-hydraulic simulation are performed on the shutdown operating condition of the main pump to determine a plurality of transient events corresponding to the design baseline operating condition in the nuclear reactor, the frequency of occurrence of each of the transient events, and a deviation from nucleate boiling risk value corresponding to each of the transient events, wherein the shutdown operating condition is the operating condition corresponding to the main pump in the state after the power failure; determining a first target transient event from the plurality of transient events according to the occurrence frequency of each transient event and the deviation from nucleate boiling risk value corresponding to each transient event, wherein the operating condition corresponding to the first target transient event is the first target operating condition; determining a first initial uncertainty parameter range when the deviation from nucleate boiling risk value corresponding to the first target operating condition is greater than a first preset safety threshold; Based on the first initial uncertainty parameter range, performing an operating condition simulation on a first preset operating condition to obtain a first target uncertainty parameter range; Based on the first target uncertainty parameter range, the first target operating condition is simulated to obtain the first preset idling flow curve.

9. The method according to claim 1, characterized in that Before determining the performance test result of the main pump according to the target descent curve, the first preset idling flow curve, and the second preset idling flow curve, the method further includes: Obtaining a second assumed uncertainty parameter range corresponding to the moment of inertia of the main pump; Based on the second assumed uncertainty parameter range, a probabilistic safety analysis and thermal-hydraulic simulation are performed on the shutdown operating condition of the main pump to determine a plurality of transient events corresponding to the load condition in the nuclear reactor, the frequency of occurrence of each of the transient events, and an overpressure risk value corresponding to each of the transient events, wherein the shutdown operating condition is the operating condition corresponding to the main pump in the state after the power failure; determining a second target transient event from the plurality of transient events according to the occurrence frequency of each of the transient events and the overpressure risk value corresponding to each of the transient events, wherein the operating condition corresponding to the second target transient event is the second target operating condition; determining a second initial uncertainty parameter range when the overpressure risk value corresponding to the second target operating condition is less than a second preset safety threshold; Based on the second initial uncertainty parameter range, simulating a second preset operating condition to obtain a second target uncertainty parameter range; Based on the second target uncertainty parameter range, the second target operating condition is simulated to obtain the second preset idling flow curve.

10. A performance test system for a nuclear reactor coolant pump, characterized in that: The system comprises: an acquisition module, configured to acquire a first measurement value sequence of a main pump in a nuclear reactor after power failure, and a second measurement value of the main pump at the moment of power failure, wherein the first measurement value sequence includes a plurality of first measurement values, and the main pump is a coolant pump in the nuclear reactor; a first determining module, configured to determine an initial drop curve of the coolant flow in the primary circuit based on the first measurement value sequence and the second measurement value; a second determining module, configured to determine a target descent curve based on the initial descent curve and the coolant steady-state flow rates of each coolant loop in the primary circuit under different operating powers of the nuclear reactor; A third determination module is used to determine the performance test result of the main pump based on the target descent curve, a first preset idling flow curve, and a second preset idling flow curve, wherein the first preset idling flow curve and the second preset idling flow curve are obtained based on a preset safety analysis result, and the first preset idling flow curve and the second preset idling flow curve are used to indicate whether the performance test result meets the safety analysis requirements.

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