A method and system for automatic low-pressure full-speed cooling of nuclear power plant units

Abstract

The present invention relates to a method and system for automatic low-pressure full-speed cooling of a nuclear power plant unit, comprising: obtaining the unit operating parameters of the nuclear power unit and the state parameters of important safety equipment; the unit operating parameters include: the water loading amount of a primary circuit and the residual heat extraction state function parameters; the state parameters of important safety equipment include: the state parameters of medium-pressure injection and the state parameters of a steam generator; performing logical calculations according to the unit operating parameters and the state parameters, and outputting the logical processing results; triggering an automatic low-pressure full-speed cooling signal according to the logical processing results; and executing automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal. Based on the logical processing results, the present invention can monitor the accident condition of a large breach in a primary circuit superimposed with a failure of medium-pressure injection, and can automatically execute the action of low-pressure full-speed cooling when the accident condition is monitored, quickly alleviate the accident condition, avoid human-caused execution risks, and improve the safety margin of the unit under the accident condition.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plants, and more particularly to an automatic low-pressure full-speed cooling method and system for nuclear power plant units. Background Art

[0002] In order to ensure that the reactor can be withdrawn to a safe shutdown state under accident conditions, when a pressurized water reactor nuclear power plant has a "large breach in the primary circuit superimposed on the failure of medium-pressure safety injection" accident, the safety injection signal will trigger the automatic action of medium-pressure rapid cooling. After the medium-pressure rapid cooling is completed, the operator is required to manually fully open the steam atmosphere discharge system valve to cool the primary circuit at the maximum rate. The purpose is to quickly reduce the primary circuit pressure to below the low-pressure safety injection injection pressure head when the medium-pressure safety injection function fails, so as to inject cooling water into the primary circuit through low-pressure safety injection and restore the primary circuit water device. Therefore, the operator's manual execution of low-pressure full-speed cooling has become an important safety action to mitigate the accident of "large breach in the primary circuit superimposed on the failure of medium-pressure safety injection".

[0003] The current third-generation pressurized water reactor nuclear power generally adopts state-oriented or symptom-oriented accident procedures, which adopt a "cyclic" execution structure. In each procedure execution cycle, the operator executes the accident operation procedure sequentially, lacking emergency response to specific accident conditions. This makes it easy for the execution time of the important accident safety action "low-pressure full-speed cooling" to exceed its available time window requirements under the accident condition of "large breach superposition failure in the primary circuit". Once the execution time of this action exceeds the limit, it will cause the reactor core condition to continue to deteriorate, and even cause core damage, which has a great human execution risk. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for automatic low-pressure full-speed cooling of nuclear power plant units in view of the defects of the prior art.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing a method for automatic low-pressure full-speed cooling of a nuclear power plant unit, comprising the following steps:

[0006] Obtaining the unit operating parameters of the nuclear power unit and the state function parameters of important safety equipment; the unit operating parameters include: the primary circuit water loading and waste heat extraction state function parameters; the state parameters of the important safety equipment include: the state parameters of the medium pressure injection and the state parameters of the steam generator;

[0007] Performing logic calculations according to the unit operating parameters and the state parameters, and outputting logic processing results;

[0008] triggering an automatic low-pressure full-speed cooling signal according to the logic processing result;

[0009] Automatic low-pressure full-speed cooling is performed according to the automatic low-pressure full-speed cooling signal.

[0010] In the method for automatic low-pressure full-speed cooling of nuclear power plant units described in the present invention, the primary circuit water loading includes: pressure vessel liquid level data; the residual heat extraction state function parameters include: containment pressure data, primary circuit pressure data and primary circuit temperature data;

[0011] The pressure vessel liquid level data is monitored and output in real time through the pressure vessel liquid level instrument; the containment pressure data is monitored and output in real time through the containment pressure instrument; the primary circuit pressure data is monitored and output in real time through the primary circuit pressure instrument; the primary circuit temperature data is monitored and output in real time through the primary circuit temperature instrument;

[0012] The state parameters of the medium-pressure safety injection include: a safety injection signal, a valve position signal of the medium-pressure safety injection, a pump state signal of the medium-pressure safety injection, and an injection flow signal of the medium-pressure safety injection;

[0013] The state parameters of the steam generator include: liquid level data of the steam generator, pressure data of the steam generator and radioactivity data inside the steam generator.

[0014] In the method for automatic low-pressure full-speed cooling of a nuclear power plant unit described in the present invention, the logical calculation according to the unit operation parameters and the state parameters comprises:

[0015] Analyzing and processing the water loading amount of the primary circuit or the residual heat removal state function parameter, and outputting a first logical result;

[0016] Analyzing and processing the state parameters of the medium pressure injection, and outputting a second logic result;

[0017] Performing analysis and processing according to the state parameters of the steam generator and outputting a third logical result;

[0018] A logic calculation is performed according to the first logic result, the second logic result and the third logic result, and the logic processing result is output.

[0019] In the method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to the present invention, the analyzing and processing of the primary circuit water loading amount or the residual heat removal state function parameter and outputting a first logical result includes:

[0020] Determining whether the water filling amount of the primary circuit is degraded according to the pressure vessel liquid level data, and outputting a determination result of the degraded water filling amount of the primary circuit;

[0021] Performing a primary circuit subcooling logic calculation according to the containment pressure data, the primary circuit pressure data and the primary circuit temperature data, and outputting the subcooling data;

[0022] Determining whether the residual heat extraction state function parameter is degraded according to the supercooling degree data, and outputting a residual heat extraction state function parameter degradation determination result;

[0023] Based on the first-circuit water capacity degradation judgment result and the waste heat extraction state function parameter degradation judgment result, an OR logic calculation is performed, and the OR logic calculation result is output; the OR logic calculation result is the first logic result.

[0024] In the method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to the present invention, the analyzing and processing of the state parameters of the medium-pressure injection and outputting a second logical result comprises:

[0025] Performing logic calculation based on the valve position signal, the pump status signal and the injection flow rate to obtain the operation status result of the medium-pressure injection;

[0026] A logic calculation is performed according to the injection signal and the operation status result to obtain the second logic result.

[0027] In the method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to the present invention, the step of analyzing and processing the state parameters of the steam generator and outputting a third logical result comprises:

[0028] Comparing the liquid level data of the steam generator with a liquid level threshold, and outputting a liquid level comparison result;

[0029] Comparing the pressure data of the steam generator with a pressure threshold, and outputting a pressure comparison result;

[0030] Comparing the radioactivity data inside the steam generator with a radioactivity threshold value, and outputting a radioactivity comparison result;

[0031] A logic calculation is performed according to the liquid level comparison result, the pressure comparison result, the radioactivity comparison result and the medium-pressure rapid cooling signal, and the third logic result is output.

[0032] In the method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to the present invention, performing logical calculation according to the first logical result, the second logical result and the third logical result, and outputting the logical processing result comprises:

[0033] Perform an AND logic calculation according to the first logic result and the second logic result to obtain an AND logic calculation result;

[0034] Determine whether the primary circuit large breach superimposed medium-pressure safety injection failure accident occurs according to the AND logic calculation result, and output the primary circuit large breach superimposed medium-pressure safety injection failure accident diagnosis result;

[0035] A logical calculation is performed based on the primary circuit large breach superimposed on the medium-pressure injection failure accident diagnosis result and the third logical result, and the logical processing result is output to trigger an automatic low-pressure full-speed cooling signal for the unit.

[0036] In the method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to the present invention, performing automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal comprises:

[0037] The automatic low-pressure full-speed cooling signal drives the execution device to automatically act or stop the action.

[0038] In the method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to the present invention, after performing automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal, the method further comprises:

[0039] Continuously monitor the post-trigger pressure of the primary circuit;

[0040] Determining whether the post-trigger pressure reaches a set value;

[0041] If yes, cancel the mandatory signal.

[0042] The present invention also provides a nuclear power plant unit automatic low-pressure full-speed cooling system, comprising:

[0043] An acquisition unit is used to acquire the unit operation parameters of the nuclear power unit and the state parameters of important safety equipment; the unit operation parameters include: the water loading amount of the primary circuit of the pressurized water reactor and the residual heat extraction state function parameters; the state parameters of the important safety equipment include: the state parameters of the medium pressure injection and the state parameters of the steam generator;

[0044] A logic calculation unit, which performs logic calculation according to the unit operation parameters and the state parameters, and outputs the logic processing result;

[0045] A trigger unit, used for triggering an automatic low-pressure full-speed cooling signal according to the logic processing result;

[0046] An execution unit is used to execute the automatic low-pressure full-speed cooling function according to the automatic low-pressure full-speed cooling signal.

[0047] The method and system for automatic low-pressure full-speed cooling of nuclear power plant units implemented in the present invention have the following beneficial effects: including: obtaining the unit operating parameters of the nuclear power unit and the status parameters of important safety equipment; the unit operating parameters include: the water loading capacity of the primary circuit and the residual heat extraction status function parameters; the status parameters of important safety equipment include: the status parameters of the medium-pressure injection and the status parameters of the steam generator; performing logical calculations according to the unit operating parameters and status parameters, and outputting the logical processing results; triggering an automatic low-pressure full-speed cooling signal according to the logical processing results; and executing automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal. Based on the logical processing results, the present invention can monitor the accident condition of a large breach in the primary circuit superimposed with the failure of the medium-pressure injection, and can automatically execute the low-pressure full-speed cooling action when the accident condition is monitored, quickly alleviate the accident condition, avoid human-caused execution risks, and improve the safety margin of the unit under the accident condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0049] Figure 1 It is a schematic flow chart of a method for automatic low-pressure full-speed cooling of a nuclear power plant unit provided by an embodiment of the present invention;

[0050] Figure 2 It is a logic diagram of a method for automatic low-pressure full-speed cooling of a nuclear power plant unit provided by an embodiment of the present invention;

[0051] Figure 3 is a logic diagram of a second logic result provided by an embodiment of the present invention;

[0052] Figure 4 is a logic diagram of a third logic result provided by an embodiment of the present invention;

[0053] Figure 5 It is a logic diagram of automatic low-pressure full-speed cooling signal triggering provided by an embodiment of the present invention;

[0054] Figure 6 It is a schematic diagram of the execution flow after the automatic low-pressure full-speed cooling signal is triggered provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0056] The present invention continuously monitors the important unit operating parameters of the nuclear power unit and the status of important safety equipment, and obtains corresponding characteristic parameters through relevant logical configuration to diagnose the accident condition of "a large rupture in the primary circuit superimposed on the failure of medium-pressure safety injection", and after monitoring the accident condition, it can automatically execute the low-pressure full-speed cooling action to quickly alleviate the accident condition and improve the safety margin of the nuclear power unit under the accident condition.

[0057] Specifically, refer to Figure 1 , which is a flow chart of an optional embodiment of the automatic low-pressure full-speed cooling method for a nuclear power plant unit provided by the present invention.

[0058] like Figure 1 As shown, the automatic low-pressure full-speed cooling method for a nuclear power plant unit includes the following steps:

[0059] Step S101, obtaining the unit operating parameters of the nuclear power unit and the status parameters of important safety equipment. The unit operating parameters include: primary circuit water loading and waste heat extraction status function parameters; the status parameters of important safety equipment include: medium pressure injection status parameters and steam generator status parameters.

[0060] Optionally, in an embodiment of the present invention, the water filling amount of a primary circuit includes: pressure vessel liquid level data; the residual heat extraction state functional parameters include: containment pressure data, primary circuit pressure data and primary circuit temperature data.

[0061] Among them, the pressure vessel liquid level data is monitored and output in real time through the pressure vessel liquid level instrument; the containment pressure data is monitored and output in real time through the containment pressure instrument; the primary circuit pressure data is monitored and output in real time through the primary circuit pressure instrument; the primary circuit temperature data is monitored and output in real time through the primary circuit temperature instrument.

[0062] Optionally, in an embodiment of the present invention, the state parameters of the medium-pressure safety injection include: an injection signal, a valve position signal of the medium-pressure safety injection, a pump state signal of the medium-pressure safety injection, and an injection flow signal of the medium-pressure safety injection.

[0063] The status parameters of the steam generator include: liquid level data of the steam generator, pressure data of the steam generator and radioactivity data inside the steam generator.

[0064] Step S102: perform logic calculations based on the unit operation parameters and state parameters, and output the logic processing results.

[0065] In some embodiments, logical calculations based on the unit operating parameters and state parameters include: analyzing and processing a circuit water capacity or waste heat extraction state function parameters, and outputting a first logical result; analyzing and processing the state parameters of the medium pressure injection, and outputting a second logical result; analyzing and processing the state parameters of the steam generator, and outputting a third logical result; and performing logical calculations based on the first logical result, the second logical result, and the third logical result.

[0066] Optionally, in some embodiments, the parameters of the water filling amount in a first circuit or the residual heat export status function are analyzed and processed, and a first logical result is output, including: judging whether the water filling amount in a first circuit is degraded according to the liquid level data of the pressure vessel, and outputting the judgment result of the degradation of the water filling amount in a first circuit; performing a logical calculation of the supercooling degree of a first circuit according to the containment pressure data, the pressure data of the first circuit, and the temperature data of the first circuit, and outputting the supercooling data; judging whether the residual heat export status function is degraded according to the supercooling data, and outputting the judgment result of the degradation of the residual heat export status function; performing an OR logical calculation based on the judgment result of the degradation of the water filling amount in a first circuit and the judgment result of the degradation of the residual heat export status function, and outputting the OR logical calculation result; the OR logical calculation result is the first logical result.

[0067] Specifically, judging whether the water filling amount of the primary circuit is degraded according to the pressure vessel liquid level data can be judged by comparing the pressure vessel liquid level data with the bottom liquid level data of the primary circuit heat pipe section. When the pressure vessel liquid level data is less than the bottom liquid level data of the primary circuit heat pipe section, it can be judged that the water filling amount of the primary circuit is degraded.

[0068] In the embodiment of the present invention, the subcooling data can be calculated by configuring and calculating using the calculation method of the existing pressurized water reactor unit.

[0069] Among them, judging whether the residual heat export state function parameter is degraded according to the supercooling data can be done by comparing the supercooling data with the supercooling low threshold value. If the supercooling data is less than the supercooling low threshold value (-∑), it is judged that the residual heat export state function parameter is degraded.

[0070] Optionally, in an embodiment of the present invention, if Figure 2 As shown, the first logic result can be obtained by performing a logical OR calculation on the primary circuit water capacity degradation judgment result and the residual heat extraction state function degradation judgment result. The first logic result is 1 or 0. That is, when the primary circuit water capacity is degraded, the residual heat extraction state function parameter is degraded, or both the primary circuit water capacity and the residual heat extraction state function parameter are degraded, the first logic result is 1, and when neither the primary circuit water capacity nor the residual heat extraction state function parameter is degraded, the first logic result is 0.

[0071] In some embodiments, the state parameters of the medium-pressure injection are analyzed and processed, and the second logical result is output, including: performing logical calculations based on the valve position signal, the pump state signal, and the injection flow signal to obtain the operating state result of the medium-pressure injection; performing logical calculations based on the injection signal and the operating state result to obtain the second logical result.

[0072] Specifically, Figure 3 As shown, the status monitoring of medium-pressure safety injection is carried out by monitoring whether the large break superimposed on the medium-pressure safety injection in a circuit is in operation when the safety injection signal exists.

[0073] Among them, when the injection signal exists, it is judged whether the valve is operating correctly based on the valve position signal, whether the pump is running based on the pump status signal, and whether the injection flow meets the requirements.

[0074] like Figure 3 As shown, when the injection signal exists, but the three MHSIs are not running (that is, the MHSI related valves fail to operate correctly, the MHSI pumps are not running, and the MHSI injection flow rate fails to meet the requirements), it indicates that all three MHSIs have failed. At this time, the second logical result obtained is MHSI failure.

[0075] In some embodiments, analysis and processing are performed based on the state parameters of the steam generator, and outputting a third logical result includes: comparing the liquid level data of the steam generator with the liquid level threshold, and outputting the liquid level comparison result; comparing the pressure data of the steam generator with the pressure threshold, and outputting the pressure comparison result; comparing the internal radioactivity data of the steam generator with the radioactivity threshold, and outputting the radioactivity comparison result; performing logical calculations based on the liquid level comparison result, the pressure comparison result, the radioactivity comparison result and the medium-pressure rapid cooling signal, and outputting the third logical result.

[0076] Specifically, in the embodiment of the present invention, the third logic result is the state monitoring result of the steam generator, wherein the state monitoring result of the steam generator includes: usable and unusable.

[0077] like Figure 4 As shown, the liquid level data of the steam generator is represented by (LSG), and the pressure data of the steam generator is represented by (PSG).

[0078] like Figure 4As shown, when the medium-pressure rapid cooling signal exists, the primary circuit performs a rapid cooling action through the steam generator (SG) and the steam atmospheric discharge system (VDA) and a certain cooling rate. At this time, the low-pressure full-speed cooling cannot be performed through the steam generator and the steam atmospheric discharge system; when the liquid level data of the steam generator is less than the low liquid level set value, or the pressure data of the steam generator is greater than the high pressure set value, the primary circuit heat cannot be exported through the steam generator. At this time, the steam generator cannot be used, that is, the third logic result is a steam generator unusable signal; when the radioactivity inside the steam generator is high, in order to ensure radioactivity containment, at this time, the steam generator cannot be used, that is, the third logic result is a steam generator unusable signal. Only when the pressure data of the steam generator is less than the high pressure set value, the liquid level data of the steam generator is greater than the low liquid level set value and the high radioactivity alarm inside the steam generator does not exist, the steam generator can be used, that is, the third logic result is a steam generator usable signal.

[0079] In some embodiments, performing logical calculations based on the first logical result, the second logical result, and the third logical result, and outputting the logical processing results includes: performing an AND logical calculation based on the first logical result and the second logical result to obtain the AND logical calculation result; judging whether a large break in a single circuit superimposed on a medium-pressure safety injection failure accident has occurred based on the AND logical calculation result, and outputting a diagnosis result of a large break in a single circuit superimposed on a medium-pressure safety injection failure accident; performing logical calculations based on the diagnosis result of a large break in a single circuit superimposed on a medium-pressure safety injection failure accident and the third logical result, and outputting the logical processing result to trigger an automatic low-pressure full-speed cooling signal for the unit.

[0080] Specifically, Figure 2 As shown, when the first logic result is 1 and the second logic result is a medium-pressure safety injection failure signal, it can be judged that the AND logic calculation result is 1. At this time, it can be diagnosed that a large circuit rupture superimposed on a medium-pressure safety injection failure accident has occurred in the unit, and the third logic result is combined with the AND logic calculation to obtain the logic processing result.

[0081] Step S103: triggering an automatic low-pressure full-speed cooling signal according to the logic processing result.

[0082] Optionally, in the embodiment of the present invention, the logic processing result includes 1 or 0. When the logic processing result is 1, the automatic low-voltage full-speed cooling signal is triggered; when the logic processing result is 0, the automatic low-voltage full-speed cooling signal is not triggered.

[0083] In a specific embodiment, Figure 5 As shown, taking a pressurized water reactor nuclear power plant as an example, the automatic low-pressure full-speed cooling signal triggering of the nuclear power plant is explained. Figure 5In the figure, L RPV is used to indicate the primary circuit liquid level data, B1HL is used to indicate the primary circuit pipe bottom liquid level, △Tsat is used to indicate the primary circuit subcooling data, -∑ is used to indicate the subcooling threshold, and P HL indicates the low-pressure injection pressure data.

[0084] like Figure 5 As shown in the figure, by real-time monitoring of the accident condition of "large breach in the primary circuit superimposed on failure of medium-pressure safety injection", it is necessary to ensure that during operation, at least one steam generator and its corresponding steam atmospheric discharge system can operate correctly to export the heat of the primary circuit. At the same time, the purpose of this automatic action is to ensure that the low-pressure safety injection injects cooling water into the primary circuit to restore the water volume of the primary circuit and ensure the continuous export of residual heat from the core. Therefore, when the pressure of the primary circuit is lower than the injection pressure threshold of the low-pressure safety injection, the low-pressure safety injection can be injected normally, and there is no need to perform the low-pressure full-speed cooling action.

[0085] Step S104, executing the automatic low-pressure full-speed cooling function according to the automatic low-pressure full-speed cooling signal.

[0086] In some embodiments, performing automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal includes: driving the execution device to automatically act or stop the action according to the automatic low-pressure full-speed cooling signal.

[0087] The actuator can be a valve for the steam atmosphere discharge system. Figure 2 As shown, when the automatic low-pressure full-speed cooling signal is triggered, the device driver module can drive the relevant valves of the steam atmosphere discharge system to perform automatic action or stop action to complete the automatic low-pressure full-speed cooling. Figure 2 As shown, automatic low-pressure full-speed cooling is achieved by driving the A-row pipeline valves, the B-row pipeline valves and the C-row pipeline valves of the steam atmosphere discharge system to automatically operate or stop operating.

[0088] Further, in some embodiments, after performing automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal, the method further includes:

[0089] Step S601, continuously monitoring the post-trigger pressure of a circuit.

[0090] Step S602: Determine whether the pressure after triggering reaches the set value.

[0091] Step S603: If yes, cancel the forced signal.

[0092] Specifically, when the automatic low-pressure full-speed cooling signal is triggered, the device action is driven by the device driver module. When the primary circuit pressure reaches below the low-pressure injection pressure, the cut-off module is activated to stop the low-pressure full-speed cooling function. After that, the primary circuit state can be manually controlled by the operator in the main control room.

[0093] like Figure 6 In the figure, a pressurized water reactor nuclear power plant is taken as an example to illustrate the automatic low-pressure full-speed cooling and cut-off logic of the nuclear power plant.

[0094] Among them, the steam atmosphere discharge system of the pressurized water reactor nuclear power plant is equipped with 3 rows of steam atmosphere discharge valves, and each row of steam atmosphere discharge valves is arranged on the main steam pipeline corresponding to the three steam generators. After receiving the automatic low-pressure full-speed cooling signal, the 3 rows of steam atmosphere discharge valves are forced to the automatic open position and no longer receive the operator's manual adjustment signal. Continuously monitor the pressure of the primary circuit. When the pressure of the primary circuit reaches the set value, stop the automatic low-pressure full-speed cooling, that is, automatically cancel the forced signal of all steam atmosphere discharge system pipelines, and accept the operator's manual adjustment. In addition, the operator can also be set to manually cut off the low-pressure full-speed cooling function of the unit, that is, cancel the automatic low-pressure full-speed cooling action of the unit when the operator needs to intervene urgently.

[0095] Furthermore, after the automatic low-pressure full-speed cooling of the nuclear power unit is triggered, the sound and light alarm system in the main control room can remind the operator of the automatic action triggering, so that the operator can call up the relevant display screen, check the correct operation of the relevant equipment, and monitor the status of the primary circuit parameters.

[0096] The automatic low-pressure full-speed cooling method for a nuclear power plant unit in an embodiment of the present invention can automatically perform a low-pressure full-speed cooling function under the design expansion accident condition of "large breach in the primary circuit superimposed on medium-pressure rapid cooling failure" of a pressurized water reactor nuclear power unit. The method can realize automatic diagnosis of the design expansion condition accident through real-time monitoring of the unit state, and immediately take mitigation actions for the accident through relevant safety facilities, such as quickly restoring the primary circuit water loading, quickly reducing the primary circuit pressure to below the injection pressure of the low threshold, and injecting the core emergency cooling water into the reactor coolant system faster. At the same time, the method can also significantly improve the operator's response efficiency to the accident condition, meet the available time window of low-pressure full-speed cooling response to the accident, avoid core damage due to exceeding the available time window of important mitigation actions, and can also reduce the operator's workload and avoid human risks. In addition, this has great positive significance for timely mitigating the deterioration of the unit state parameters caused by the accident and improving the safety margin of the pressurized water reactor nuclear power unit in the accident situation.

[0097] In addition, the above-mentioned nuclear power plant unit accident condition monitoring, automatic operation and sound and light alarm will help further improve the intelligence and automation level of nuclear power plants.

[0098] The present invention also provides an automatic low-pressure full-speed cooling system for a nuclear power plant unit, which can be used to implement the automatic low-pressure full-speed cooling method for a nuclear power plant unit disclosed in an embodiment of the present invention.

[0099] Specifically, the automatic low-pressure full-speed cooling system of nuclear power plant units includes:

[0100] The acquisition unit is used to obtain the unit operation parameters of the nuclear power unit and the status parameters of important safety equipment. The unit operation parameters include: the water loading of the primary circuit of the pressurized water reactor and the residual heat extraction status function parameters; the status parameters of important safety equipment include: the status parameters of the medium pressure injection and the status parameters of the steam generator.

[0101] The logic calculation unit performs logic calculations based on the unit's operating parameters and status parameters, and outputs the logic processing results.

[0102] The trigger unit is used to trigger the automatic low-pressure full-speed cooling signal according to the logic processing result.

[0103] The execution unit is used to execute the automatic low-pressure full-speed cooling function according to the automatic low-pressure full-speed cooling signal.

[0104] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0105] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0106] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0107] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot limit the scope of protection of the present invention. All equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for automatic low-pressure full-speed cooling of nuclear power plant units. It is characterized in that The following steps are involved: Obtain the unit operating parameters of the nuclear power unit and the status parameters of important safety equipment; The unit operation parameters include: primary circuit water loading and waste heat extraction state function parameters; the state parameters of the important safety equipment include: medium pressure injection state parameters and steam generator state parameters; Performing logic calculations according to the unit operating parameters and the state parameters, and outputting logic processing results; According to the logic processing result, an automatic low-pressure full-speed cooling signal is triggered; the logic processing result includes 1 or 0; when the logic processing result is 1, an automatic low-pressure full-speed cooling signal is triggered; Execute the automatic low-pressure full-speed cooling function according to the automatic low-pressure full-speed cooling signal; The performing of automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal comprises: driving an execution device to automatically act or stop acting according to the automatic low-pressure full-speed cooling signal; the execution device comprises: a steam atmosphere discharge system valve.

2. The automatic low-pressure full-speed cooling method for a nuclear power plant unit according to claim 1, It is characterized in that The primary circuit water filling volume includes: pressure vessel liquid level data; the residual heat extraction state function parameters include: containment pressure data, primary circuit pressure data and primary circuit temperature data; The pressure vessel liquid level data is monitored and output in real time through the pressure vessel liquid level instrument; the containment pressure data is monitored and output in real time through the containment pressure instrument; the primary circuit pressure data is monitored and output in real time through the primary circuit pressure instrument; the primary circuit temperature data is monitored and output in real time through the primary circuit temperature instrument; The state parameters of the medium-pressure safety injection include: a safety injection signal, a valve position signal of the medium-pressure safety injection, a pump state signal of the medium-pressure safety injection, and an injection flow signal of the medium-pressure safety injection; The state parameters of the steam generator include: liquid level data of the steam generator, pressure data of the steam generator and radioactivity data inside the steam generator.

3. The automatic low-pressure full-speed cooling method for a nuclear power plant unit according to claim 2, It is characterized in that The performing logical calculation according to the unit operation parameter and the state parameter and outputting the logical processing result comprises: Analyzing and processing the water loading amount of the primary circuit or the residual heat removal state function parameter, and outputting a first logical result; Analyzing and processing the state parameters of the medium pressure injection, and outputting a second logic result; Performing analysis and processing according to the state parameters of the steam generator and outputting a third logical result; A logic calculation is performed according to the first logic result, the second logic result and the third logic result, and the logic processing result is output.

4. The method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to claim 3, It is characterized in that The analyzing and processing the primary circuit water loading amount or the residual heat removal state function parameter and outputting a first logic result includes: Determining whether the water filling amount of the primary circuit is degraded according to the pressure vessel liquid level data, and outputting a determination result of the degraded water filling amount of the primary circuit; Performing a primary circuit subcooling logic calculation according to the containment pressure data, the primary circuit pressure data and the primary circuit temperature data, and outputting the subcooling data; Determining whether the residual heat extraction state function parameter is degraded according to the supercooling degree data, and outputting a residual heat extraction state function parameter degradation determination result; Based on the first-circuit water capacity degradation judgment result and the waste heat extraction state function parameter degradation judgment result, an OR logic calculation is performed, and the OR logic calculation result is output; the OR logic calculation result is the first logic result.

5. The automatic low-pressure full-speed cooling method for a nuclear power plant unit according to claim 3, It is characterized in that The analyzing and processing the state parameters of the medium pressure injection and outputting a second logic result comprises: Performing logic calculation based on the valve position signal, the pump status signal and the injection flow rate signal to obtain the operation status result of the medium-pressure injection; A logic calculation is performed according to the injection signal and the operation status result to obtain the second logic result.

6. The method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to claim 3, It is characterized in that The performing analysis and processing according to the state parameter of the steam generator and outputting a third logical result comprises: Comparing the liquid level data of the steam generator with a liquid level threshold, and outputting a liquid level comparison result; Comparing the pressure data of the steam generator with a pressure threshold, and outputting a pressure comparison result; Comparing the radioactivity data inside the steam generator with a radioactivity threshold value, and outputting a radioactivity comparison result; A logic calculation is performed according to the liquid level comparison result, the pressure comparison result, the radioactivity comparison result and the medium-pressure rapid cooling signal, and the third logic result is output.

7. The method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to claim 3, It is characterized in that The performing logic calculation according to the first logic result, the second logic result and the third logic result, and outputting the logic processing result comprises: Perform an AND logic calculation according to the first logic result and the second logic result to obtain an AND logic calculation result; Determine whether the primary circuit large breach superimposed medium-pressure safety injection failure accident occurs according to the AND logic calculation result, and output the primary circuit large breach superimposed medium-pressure safety injection failure accident diagnosis result; A logical calculation is performed based on the primary circuit large breach superimposed on the medium-pressure injection failure accident diagnosis result and the third logical result, and the logical processing result is output to trigger an automatic low-pressure full-speed cooling signal for the unit.

8. The method for automatic low-pressure full-speed cooling of a nuclear power plant unit according to claim 1, It is characterized in that After performing automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal, the method further includes: Continuously monitor the post-trigger pressure of the primary circuit; Determining whether the post-trigger pressure reaches a set value; If yes, cancel the mandatory signal.

9. An automatic low-pressure full-speed cooling system for nuclear power plant units. It is characterized in that include: An acquisition unit, used to acquire the unit operating parameters of the nuclear power unit and the status parameters of important safety equipment; The operating parameters of the unit include: the primary coolant inventory of the pressurized water reactor and the functional parameters of the residual heat removal status; the status parameters of the important safety equipment include: the status parameters of the medium-pressure safety injection and the status parameters of the steam generator; A logic calculation unit performs logic calculations based on the operating parameters of the unit and the status parameters, and outputs a logic processing result; A trigger unit is used to trigger an automatic low-pressure full-speed cooling signal according to the logic processing result; the logic processing result includes 1 or 0; when the logic processing result is 1, the automatic low-pressure full-speed cooling signal is triggered; An execution unit is used to execute the automatic low-pressure full-speed cooling function according to the automatic low-pressure full-speed cooling signal; the execution of the automatic low-pressure full-speed cooling according to the automatic low-pressure full-speed cooling signal includes: driving the execution equipment to automatically act or stop acting according to the automatic low-pressure full-speed cooling signal; the execution equipment includes: the steam atmospheric discharge system valve.

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