Nuclear reactor primary circuit water injection method and device

Abstract

This application provides a method and apparatus for water injection in the primary loop of a nuclear reactor, belonging to the field of nuclear control. The method includes: obtaining the original enthalpy and residual enthalpy of the reactor core; obtaining the critical time for successful water injection and the critical time for unsuccessful water injection corresponding to the primary loop of the reactor core; determining the critical total flow rate for successful water injection in the primary loop based on the critical time for successful water injection, the original enthalpy and the residual enthalpy, and the energy conservation principle of the reactor core; and determining the critical total flow rate for unsuccessful water injection in the primary loop based on the critical time for unsuccessful water injection, the original enthalpy and the residual enthalpy, and the energy conservation principle of the primary loop; and controlling the total flow rate of water injection in the primary loop based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection. This application embodiment can improve the efficiency of primary loop water injection.

Description

Technical Field

[0001] This application relates to the field of nuclear control technology, and in particular to a method and apparatus for injecting water into the primary loop of a nuclear reactor. Background Technology

[0002] After a nuclear power plant accident, the core temperature gradually rises because the decay heat cannot be continuously removed, eventually leading to a core meltdown. Water injection in the primary coolant loop can effectively remove heat from the core, thus preventing further escalation of the nuclear accident and protecting lives and property. Therefore, in severe accident management procedures, to prevent core meltdown, it is necessary to establish and implement measures to ensure the integrity of the core by guaranteeing water injection in the primary coolant loop.

[0003] Currently, in the research and analysis of severe accident management strategies in nuclear power plants, phenomena such as plant-wide power outages coupled with small-break water loss exceeding design baselines are often quite complex, involving numerous influencing factors. This introduces significant uncertainty when implementing primary loop water injection, often requiring calculation and analysis using severe accident mechanism programs. However, such calculations are complex, time-consuming, and have limitations. Therefore, a universal and efficient primary loop water injection method is needed. Summary of the Invention

[0004] The main objective of this application is to provide a method and apparatus for primary loop water injection in a nuclear reactor, aiming to improve the efficiency of primary loop water injection.

[0005] To achieve the above objectives, a first aspect of this application proposes a primary loop water injection method, the method comprising:

[0006] The original enthalpy and residual enthalpy of the reactor core are obtained; the original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat, and the stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core; the residual enthalpy is the enthalpy after successful water injection into the reactor core, and successful water injection into the reactor core indicates that the reactor core is submerged in coolant and cooled to the saturation temperature;

[0007] Obtain the critical time for successful water injection and the critical time for unsuccessful water injection corresponding to the primary loop of the reactor core;

[0008] Based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core, the critical total flow rate for successful water injection in the primary loop is determined; and based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop, the critical total flow rate for unsuccessful water injection in the primary loop is determined.

[0009] The total water injection flow rate of the first loop is controlled based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection.

[0010] In some embodiments, the step of determining the critical total flow rate for successful water injection of the reactor core based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core; and the step of determining the critical total flow rate for unsuccessful water injection of the primary loop based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop, includes:

[0011] Based on the principle of energy conservation in the reactor core, the energy conservation calculation formula for the reactor core is determined; the energy conservation calculation formula is as follows:

[0012] E in -E out =E fill -(E store +E ox +E decay )

[0013] Among them, E in E is the injection enthalpy of the reactor core. out E is the effluent enthalpy of the reactor core. fill E is the residual enthalpy value. store +E ox +E decay The original enthalpy value;

[0014] An equivalent water injection method is used to determine the formulas for calculating the injection enthalpy and the outflow enthalpy of the reactor core; both the injection enthalpy and outflow enthalpy calculation formulas include the water injection duration of the primary loop and the total water injection flow rate of the primary loop.

[0015] Based on the energy conservation calculation formula, the injection enthalpy calculation formula, and the outflow enthalpy calculation formula, the total water injection flow rate calculation formula for the primary loop is determined.

[0016] Substituting the critical time for successful water injection, the original enthalpy value, and the remaining enthalpy value into the formula for calculating the total water injection flow rate, the critical total water injection flow rate for successful water injection of the reactor core is obtained.

[0017] Substituting the critical time of unsuccessful water injection, the original enthalpy value, and the remaining enthalpy value into the formula for calculating the total water injection flow rate, the critical total flow rate of the reactor core in case of unsuccessful water injection is obtained.

[0018] In some embodiments, the step of determining the injection enthalpy and effluent enthalpy calculation formulas of the reactor core using an equivalent water injection method includes:

[0019] Obtain the equivalent water injection specific enthalpy and equivalent water injection density of the primary loop, as well as the coolant charge and steam specific enthalpy under saturated conditions when the reactor core is submerged, wherein the saturated state is the state corresponding to the saturation temperature;

[0020] The formula for calculating the injection enthalpy is determined based on the equivalent injection density and the equivalent injection ratio enthalpy; the formula for calculating the injection enthalpy is as follows:

[0021] E in =Q v,in ρ in,eq H in,eq t inj

[0022] The formula for calculating the outflow enthalpy is determined based on the equivalent water injection density, the coolant charge, and the specific enthalpy of the steam; the formula for calculating the outflow enthalpy is as follows:

[0023] E out =Q m,out H g t inj

[0024] in, Q v,in ρ is the total flow rate of the primary loop water injection. in,eq Let m be the equivalent water injection density of the first loop. fill The coolant charge (t) during reactor core flooding. inj Q is the water injection duration of the first loop. m,out is the mass flow rate out of the reactor core; is the specific enthalpy of steam under saturated conditions; E in H is the injection enthalpy value. in,eq The equivalent water injection enthalpy of the first loop is given.

[0025] In some embodiments, the step of determining the total injection flow rate of the primary loop based on the energy conservation calculation formula, the injection enthalpy calculation formula, and the outflow enthalpy calculation formula includes:

[0026] Substituting the injection enthalpy calculation formula and the outflow enthalpy calculation formula into the energy conservation calculation formula, the total injection flow rate of the first loop is calculated; the total injection flow rate of the first loop is calculated as follows:

[0027]

[0028] Among them, Q v,in The total water injection flow rate of the first loop is given.

[0029] In some embodiments, the step of controlling the total injection flow rate of the primary loop based on the critical total flow rate for successful injection and the critical total flow rate for unsuccessful injection includes:

[0030] Based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection, the system is divided into a successful water injection zone, an unsuccessful water injection zone, and an uncertain water injection zone. The successful water injection zone is the area where the total water injection flow rate of the first loop is greater than the critical total flow rate for successful water injection. The unsuccessful water injection zone is the area where the total water injection flow rate of the first loop is less than the critical total flow rate for unsuccessful water injection. The uncertain water injection zone is the area where the total water injection flow rate of the first loop is less than the critical total flow rate for successful water injection but greater than the critical total flow rate for unsuccessful water injection.

[0031] The total water injection flow rate of the first loop is controlled to fall into the successful water injection zone.

[0032] In some embodiments, the step of obtaining the original enthalpy and residual enthalpy of the reactor core includes:

[0033] To obtain the total energy of the reactor core, including stored energy, oxidation energy, and decay heat.

[0034] The original enthalpy value is determined by summing the energy stored in the reactor core, the oxidation energy, and the total decay heat energy.

[0035] Obtain the void fraction during reactor core flooding, the volume of the reactor core, and the density of water under saturation conditions;

[0036] The coolant volume when the reactor core is submerged is obtained by multiplying the difference between the cavitation fraction when the reactor core is submerged and the volume of the reactor core.

[0037] The coolant loading amount during reactor core flooding is obtained by multiplying the coolant volume during reactor core flooding by the density of water under saturation.

[0038] Obtain the specific enthalpy of water under the saturated state;

[0039] The residual enthalpy is obtained by multiplying the coolant charge of the submerged core by the enthalpy of water under saturation.

[0040] In some embodiments, the step of obtaining the total energy of the reactor core, including stored energy, oxidation energy, and decay heat, includes:

[0041] Obtain the total mass and specific heat of the reactor core;

[0042] The heat capacity is obtained by multiplying the total mass of the reactor core by the specific heat of the core.

[0043] The energy storage capacity of the reactor core is obtained by multiplying the heat capacity by the difference between the current temperature of the reactor core and the saturation temperature of the reactor core.

[0044] Obtain the total mass of metallic zirconium in the reactor core, the molar mass of zirconium, the oxidation ratio of metallic zirconium in the reactor core, and the energy released by the oxidation of one mole of metallic zirconium.

[0045] The number of moles of zirconium is obtained by dividing the total mass of metallic zirconium in the reactor core by the molar mass of zirconium.

[0046] The oxidation energy is obtained by multiplying the number of moles of zirconium by the oxidation ratio of metallic zirconium in the reactor core and the energy released by the oxidation of one mole of metallic zirconium.

[0047] Obtain the power linearity coefficient, power exponential coefficient, and the time interval from reactor shutdown to the start of water injection;

[0048] Based on the power linearity coefficient, the power exponential coefficient, and the time interval from reactor shutdown to the start of water injection, a formula for calculating the total decay heat energy is determined; wherein, the formula for calculating the total decay heat energy is:

[0049]

[0050] Where α is the power linearity coefficient, β is the power exponential coefficient, 0 < β < 1, t start E is the interval between reactor shutdown and water injection. decay This represents the total energy of decay heat.

[0051] Substituting the critical time for successful water injection or the critical time for unsuccessful water injection into the calculation formula for the total decay heat energy, the total decay heat energy is obtained.

[0052] To achieve the above objectives, a second aspect of this application provides a primary-loop water injection device, the device comprising:

[0053] An enthalpy acquisition module is used to acquire the original enthalpy and remaining enthalpy of the reactor core. The original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat. The stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core. The remaining enthalpy is the enthalpy after successful water injection into the reactor core. Successful water injection into the reactor core indicates that the reactor core has been submerged in coolant and cooled to the saturation temperature.

[0054] The time acquisition module is used to acquire the critical time for successful water injection and the critical time for unsuccessful water injection corresponding to the primary loop of the reactor core.

[0055] The determining module is used to determine the critical total flow rate for successful water injection of the primary loop based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core; and to determine the critical total flow rate for unsuccessful water injection of the primary loop based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop.

[0056] The control module is used to control the total water injection flow rate of the primary loop based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection.

[0057] To achieve the above objectives, a third aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect.

[0058] To achieve the above objectives, a fourth aspect of the present application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0059] The method and apparatus for injecting water into the primary loop of a nuclear reactor proposed in this application obtain the original enthalpy and the remaining enthalpy of the reactor core. The original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat. The stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core. The remaining enthalpy is the enthalpy after successful water injection into the reactor core. Successful water injection into the reactor core indicates that the reactor core is submerged in coolant and cooled to the saturation temperature. Secondly, the method and apparatus for injecting water into the primary loop of the reactor core are obtained. The corresponding critical times for successful and unsuccessful water injection are determined. Then, based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core, the critical total flow rate for successful water injection in the primary loop is determined. Similarly, based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop, the critical total flow rate for unsuccessful water injection in the primary loop is determined. Finally, the total flow rate of water injection in the primary loop is controlled based on these two values. In other words, the critical total flow rate for unsuccessful and successful water injection in the primary loop is determined based on the critical time, the original enthalpy value, and the remaining enthalpy value, thereby controlling the total flow rate of water injection in the primary loop. In this way, by controlling the total flow rate of water injection in the primary loop, the reactor core is effectively cooled, preventing further deterioration of a nuclear accident and improving the efficiency of water injection in the primary loop. Attached Figure Description

[0060] Figure 1 This is a flowchart of the primary loop water injection method provided in the embodiments of this application;

[0061] Figure 2 This is a schematic diagram of the primary loop water injection device provided in the embodiments of this application;

[0062] Figure 3 This is a schematic diagram of the hardware structure of the electronic device provided in an embodiment of the present application. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0064] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0066] The primary loop water injection method, apparatus, electronic device, and storage medium provided in this application are specifically described through the following embodiments. First, the primary loop water injection method in this application is described.

[0067] The one-loop water injection method provided in this application relates to the field of computer technology. The one-loop water injection method provided in this application can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, etc.; the server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms; the software can be an application implementing the one-loop water injection method, but is not limited to the above forms.

[0068] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0069] Figure 1 This is an optional flowchart of the primary loop water injection method provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps S101 to S104.

[0070] Step S101: Obtain the original enthalpy and remaining enthalpy of the reactor core; the original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat, the stored energy being determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core; the remaining enthalpy is the enthalpy after successful water injection into the reactor core, successful water injection into the reactor core indicating that the reactor core is submerged in coolant and cooled to the saturation temperature;

[0071] Step S102: Obtain the critical time for successful water injection and the critical time for unsuccessful water injection corresponding to the primary loop of the reactor core;

[0072] Step S103: Determine the critical total flow rate for successful water injection of the primary loop based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core; and determine the critical total flow rate for unsuccessful water injection of the primary loop based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop.

[0073] Step S104: Control the total water injection flow rate of the first loop based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection.

[0074] Steps S101 to S104, as illustrated in this embodiment, involve obtaining the original enthalpy and remaining enthalpy of the reactor core. The original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat. The stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core. The remaining enthalpy is the enthalpy after successful water injection into the reactor core. Successful water injection indicates that the reactor core is submerged in coolant and cooled to the saturation temperature. Next, the primary loop pressure of the reactor core is obtained... The primary loop is first determined by identifying the critical time for successful water injection and the critical time for unsuccessful water injection. Then, based on the successful water injection critical time, the original enthalpy, the remaining enthalpy, and the energy conservation principle of the reactor core, the critical total flow rate for successful water injection in the primary loop is determined. Similarly, based on the unsuccessful water injection critical time, the original enthalpy, the remaining enthalpy, and the energy conservation principle of the primary loop, the critical total flow rate for unsuccessful water injection in the primary loop is determined. Finally, the total water injection flow rate of the primary loop is controlled based on these two values. In other words, the critical total flow rate for unsuccessful water injection and the critical total flow rate for successful water injection in the primary loop are determined based on the critical time, the original enthalpy, and the remaining enthalpy, thereby controlling the total water injection flow rate of the primary loop. In this way, by controlling the total water injection flow rate of the primary loop, the reactor core is effectively cooled, preventing further deterioration of a nuclear accident and improving the efficiency of water injection in the primary loop.

[0075] In step S103 of some embodiments, the critical total flow rate of the primary loop for successful and unsuccessful water injection is calculated based on the time points of successful and unsuccessful water injection, combined with the original enthalpy value and the remaining enthalpy value, using the principle of energy conservation.

[0076] In step S104 of some embodiments, the total water injection flow rate of the primary loop is adjusted according to the calculated critical total flow rate for successful and unsuccessful water injection to ensure the safety and stability of the reactor core.

[0077] It should be noted that enthalpy can be a physical quantity in thermodynamics representing the energy state of a system. The original enthalpy can be the energy state during the core cooling process, including stored energy, oxidation energy, and total decay heat energy. The total decay heat energy can be calculated by replacing the water injection duration in the formula with the critical time for successful water injection corresponding to the primary loop of the reactor core, or by replacing the water injection duration in the formula with the critical time for unsuccessful water injection.

[0078] Saturation temperature can be the temperature at which liquid and vapor coexist under a given pressure. The critical time for successful water injection is the time within which water injection can be completed and the reactor core can be successfully cooled. The critical time for unsuccessful water injection is the time beyond which water injection fails and the reactor core cannot be effectively cooled. The principle of conservation of energy can be a physical law stating that energy in a closed system cannot be created or destroyed, but can only be converted from one form to another.

[0079] It should be noted that the critical time for successful water injection and the critical time for unsuccessful water injection in the primary loop of the reactor core can be obtained in the following ways: 1. By modeling the reactor core and then simulating it; 2. By statistically analyzing a large amount of primary loop water injection data collected from the reactor core.

[0080] For example, suppose a reactor core needs rapid cooling in an emergency. Its original enthalpy is 1000 J, and the remaining enthalpy after successful water injection is 500 J. The critical time for successful water injection is 30 minutes, and the critical time for unsuccessful water injection is 45 minutes. Based on the principle of energy conservation, the critical total flow rate for successful water injection is calculated to be 100 m³ / s. 3 / h, the critical total flow rate for unsuccessful water injection is 80m³ / h. 3 / h. The total flow rate of the primary circuit can be adjusted to ensure it exceeds 100 m³ / h. 3 / h can prevent core overheating.

[0081] In some embodiments, the steps described above—determining the critical total flow rate for successful water injection of the reactor core based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core; and determining the critical total flow rate for unsuccessful water injection of the primary loop based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop—include:

[0082] Based on the principle of energy conservation in the reactor core, the energy conservation calculation formula for the reactor core is determined; the energy conservation calculation formula is as follows:

[0083] E in -E out =E fill -(E store +E ox +E decay )

[0084] Among them, E in E is the injection enthalpy of the reactor core. out E is the effluent enthalpy of the reactor core. fill E is the remaining enthalpy value. store +Eox +E decay The original enthalpy value;

[0085] An equivalent water injection method is used to determine the formulas for calculating the injection enthalpy and the outflow enthalpy of the reactor core; both the injection enthalpy and outflow enthalpy calculation formulas include the water injection duration of the primary loop and the total water injection flow rate of the primary loop.

[0086] Based on the energy conservation calculation formula, the injection enthalpy calculation formula, and the outflow enthalpy calculation formula, the total water injection flow rate calculation formula for the primary loop is determined.

[0087] Substituting the critical time for successful water injection, the original enthalpy value, and the remaining enthalpy value into the formula for calculating the total water injection flow rate, the critical total water injection flow rate for successful water injection of the reactor core is obtained.

[0088] Substituting the critical time of unsuccessful water injection, the original enthalpy value, and the remaining enthalpy value into the formula for calculating the total water injection flow rate, the critical total flow rate of the reactor core in case of unsuccessful water injection is obtained.

[0089] In this embodiment, firstly, based on the principle of energy conservation, a calculation formula is established that relates the injection enthalpy, outflow enthalpy, residual enthalpy, and original enthalpy. Secondly, an equivalent water injection method is used to simplify the water injection system model, determining the calculation formulas for the injection and outflow enthalpies, both of which include the water injection duration and total water injection flow rate. Thirdly, combining the energy conservation calculation formula, the injection enthalpy calculation formula, and the outflow enthalpy calculation formula, the calculation formula for the total water injection flow rate is derived. Finally, substituting the critical time for successful and unsuccessful water injection, the original enthalpy, and the residual enthalpy into the total water injection flow rate calculation formula, the critical total flow rates for successful and unsuccessful water injection are obtained respectively. Determining the critical flow rates for successful and unsuccessful water injection helps in developing emergency measures and improving reactor safety. Simultaneously, by accurately calculating the total water injection flow rate, it is possible to ensure that the reactor core receives appropriate cooling and avoids overheating. Furthermore, calculations based on the principle of energy conservation can optimize water injection operations, reduce resource waste, and improve efficiency.

[0090] It should be noted that the injection enthalpy can be the energy carried by the coolant when it is injected into the reactor core during the water injection process. The outflow enthalpy can be the energy carried by the liquid flowing out of the reactor core during the water injection process.

[0091] In some embodiments, the step of determining the injection enthalpy and effluent enthalpy calculation formulas of the reactor core using an equivalent water injection method, as described above, includes:

[0092] Obtain the equivalent water injection specific enthalpy and equivalent water injection density of the primary loop, as well as the coolant charge and steam specific enthalpy under saturated conditions when the reactor core is submerged, wherein the saturated state is the state corresponding to the saturation temperature;

[0093] The formula for calculating the injection enthalpy is determined based on the equivalent injection density and the equivalent injection ratio enthalpy; the formula for calculating the injection enthalpy is as follows:

[0094] E in =Q v,in ρ in,eq H in,eq t inj

[0095] The formula for calculating the outflow enthalpy is determined based on the equivalent water injection density, the coolant charge, and the specific enthalpy of the steam; the formula for calculating the outflow enthalpy is as follows:

[0096] E out =Q m,out H g t inj

[0097] in, Q v,in ρ is the total flow rate of the primary loop water injection. in,eq Let m be the equivalent water injection density of the first loop. fill The coolant charge (t) during reactor core flooding. inj Q is the water injection duration of the first loop. m,out H is the mass flow rate of the reactor core outflow. g E is the specific enthalpy of vapor under saturated conditions. in H is the injection enthalpy value. in,eq The equivalent water injection ratio enthalpy of the first loop is given.

[0098] In this embodiment, firstly, the equivalent injection enthalpy and equivalent injection density of the primary coolant loop need to be obtained. Then, using the total injection flow rate, equivalent injection density, and equivalent injection enthalpy of the primary coolant loop, combined with the injection duration, a formula for calculating the injection enthalpy is determined. Secondly, the total amount of coolant in the reactor core when it is submerged is obtained, i.e., the coolant charge. Then, combining the total injection flow rate of the primary coolant loop, the equivalent injection density, the coolant charge during core submersion, and the injection duration, a formula for calculating the outflow mass flow rate from the core is obtained. Thirdly, the enthalpy of steam under saturated conditions is obtained. Finally, using the outflow mass flow rate from the core, the enthalpy of steam under saturated conditions, and the injection duration, a formula for calculating the outflow enthalpy is determined. Thus, by determining the calculation formulas for injection and outflow enthalpies, operators can optimize the water injection operation to cool the reactor core most effectively and prevent further deterioration of a nuclear accident.

[0099] It should be noted that the equivalent water injection enthalpy can be the thermal energy possessed by a unit mass of coolant during the water injection process. The equivalent water injection density can be the density of the coolant during the water injection process. The injection enthalpy can be the total thermal energy carried by the coolant when it is injected into the reactor core. The outflow enthalpy can be the total thermal energy carried by the liquid flowing out of the reactor core. The mass flow rate can be the mass passing through a certain cross section per unit time, usually expressed in kilograms per second (kg / s). The saturated steam enthalpy can be the thermal energy per unit mass of steam at saturated temperature and pressure.

[0100] For example, when the master controller implements the primary loop water injection strategy, systems or equipment that may be injected with water are taken into consideration, including the safety injection system and the core water injection system. Different water injection systems may have different flow rates and water sources, thus their water injection effects will also differ. This application embodiment calculates the core injection enthalpy value using an equivalent water injection flow rate.

[0101] Assuming that all the primary coolant flow enters the pressure vessel for core cooling, the enthalpy entering the core when multiple injection systems simultaneously inject water into the primary coolant is:

[0102]

[0103] in,

[0104] t inj Water injection duration (s),

[0105] Q v,in,i The flow rate (m³) of the primary loop water injection into system i 3 / s),

[0106] ρ in,i The water density of the primary loop injection water in system i (kg / m³) 3 ),

[0107] H in,i The specific enthalpy (J / kg) of the water injected into the primary loop of system i.

[0108] Calculate the equivalent water injection enthalpy (J / kg):

[0109]

[0110] Assuming a constant injection mass flow rate, the equivalent injection density (kg / m³) can be calculated. 3 ):

[0111]

[0112] in,

[0113] Q v,in Q is the total injection flow rate of the primary loop.v,in =∑ i Q v,in,i .

[0114] The injection enthalpy can then be calculated using the total injection flow rate, equivalent injection density, and equivalent injection ratio enthalpy.

[0115] E in =Q v,in ρ in,eq H in,eq t inj

[0116] in,

[0117] Q v,in The total flow rate of the primary circuit water injection (m³) 3 / s),

[0118] ρ in,eq Equivalent water injection density (kg / m³) 3 ),

[0119] H in,eq The equivalent water injection specific enthalpy (J / kg)

[0120] t inj The duration of water injection is in seconds.

[0121] For example, after the primary coolant is injected, assume that the primary coolant remains saturated. The injected coolant floods the reactor core, and the excess coolant outside the core flows out of the core as saturated steam. The mass flow rate of the core outflow is:

[0122]

[0123] in,

[0124] Q v,in The total flow rate of the primary circuit water injection (m³) 3 / s),

[0125] ρ in,eq Equivalent water injection density (kg / m³) 3 ),

[0126] m fill The coolant charge (kg) during reactor core flooding.

[0127] t inj The duration of water injection is in seconds.

[0128] After absorbing core heat (including core energy storage, core oxidation energy, and core decay heat), the enthalpy of the saturated steam flowing out of the core is:

[0129] E out =Qm,out H g t inj

[0130] Among them, H g Enthalpy of vapor under saturated conditions (J / kg).

[0131] In some embodiments, the step of determining the total injection flow rate of the primary loop based on the energy conservation calculation formula, the injection enthalpy calculation formula, and the outflow enthalpy calculation formula includes:

[0132] Substituting the injection enthalpy calculation formula and the outflow enthalpy calculation formula into the energy conservation calculation formula, the total injection flow rate of the first loop is calculated; the total injection flow rate of the first loop is calculated as follows:

[0133]

[0134] Among them, Q v,in The total water injection flow rate of the first loop is given.

[0135] In this embodiment, substituting the injection enthalpy calculation formula and the outflow enthalpy calculation formula into the energy conservation calculation formula yields a primary loop injection total flow rate calculation formula that includes the total injection flow rate, coolant charge, steam specific enthalpy under saturation, injection duration, equivalent injection density, equivalent injection specific enthalpy, original enthalpy, and remaining enthalpy. This precise calculation formula allows for accurate control of the primary loop injection total flow rate, ensuring proper core cooling. Furthermore, the calculation formula optimizes the injection operation, reducing water waste and improving resource utilization efficiency.

[0136] It should be noted that the total water injection flow rate of the primary loop can be the total flow rate of coolant injected into the reactor core through the primary loop system within a certain time period. The coolant charge during reactor core flooding can be the total amount of coolant when the reactor core is completely flooded. The specific enthalpy of steam under saturated conditions can be the thermal energy per unit mass of steam at saturated temperature and pressure. The water injection duration of the primary loop can be the total time from the start of water injection to the end of water injection.

[0137] For example, the time required for the primary circuit to flood the reactor core is particularly important. If the flooding time is too long, it may lead to cooling failure, which in turn may result in core meltdown or degradation.

[0138] Assume t succ The critical time for successful water injection, i.e., if the primary water injection time is less than t. succ If so, water injection will definitely be successful and can cool the reactor core. Assume t fail This is the critical time for unsuccessful water injection, i.e., if the primary water injection time exceeds t. failIf the water injection fails, the reactor core cannot be cooled. If the water injection time is greater than t... succ And less than t fail If not, it is uncertain whether the water injection was successful.

[0139] According to the principle of conservation of core energy, the difference between the injected enthalpy and the discharged enthalpy is equal to the change in core enthalpy, that is, the difference between the remaining enthalpy and the original enthalpy, as shown in the following equation:

[0140] E in -E out =E fill -(E store +E ox +E decay )

[0141] Substituting the injection enthalpy calculation formula and the outflow enthalpy calculation formula into the energy conservation calculation formula, we obtain the calculation formula for the total injection flow rate of the first loop; the calculation formula for the total injection flow rate of the first loop is:

[0142]

[0143] Success time t succ With t fail Substitute t inj This allows for the calculation of the critical flow rates for a guaranteed successful injection and the critical flow rates for a guaranteed unsuccessful injection. The current primary circuit pressure is P. prim Under these conditions, the critical flow rate for successful water injection is:

[0144]

[0145] The critical flow rate at which water injection will definitely fail is:

[0146]

[0147] In some embodiments, the step of controlling the total injection flow rate of the primary loop based on the critical total flow rate for successful injection and the critical total flow rate for unsuccessful injection includes:

[0148] Based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection, the system is divided into a successful water injection zone, an unsuccessful water injection zone, and an uncertain water injection zone. The successful water injection zone is the area where the total water injection flow rate of the first loop is greater than the critical total flow rate for successful water injection. The unsuccessful water injection zone is the area where the total water injection flow rate of the first loop is less than the critical total flow rate for unsuccessful water injection. The uncertain water injection zone is the area where the total water injection flow rate of the first loop is less than the critical total flow rate for successful water injection but greater than the critical total flow rate for unsuccessful water injection.

[0149] The total water injection flow rate of the first loop is controlled to fall into the successful water injection zone.

[0150] In this embodiment, based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection, the primary loop's total water injection flow rate control area is divided into three parts: the successful water injection zone, the unsuccessful water injection zone, and the uncertain water injection zone. Furthermore, by controlling the primary loop's total water injection flow rate to fall within the successful water injection zone, effective core cooling is ensured. Precise control of the total water injection flow rate prevents further deterioration of a nuclear accident, ensures effective core cooling, avoids overheating, and improves reactor safety. Secondly, a clearly defined flow rate control area helps operators make quick decisions, optimize water injection operations, and reduce resource waste.

[0151] It should be noted that the critical total flow rate for successful water injection is the minimum total flow rate required to ensure effective core cooling. The critical total flow rate for unsuccessful water injection is the total flow rate at which the core cannot receive sufficient cooling. The successful water injection zone is the area where the total flow rate is greater than the critical total flow rate for successful water injection, and the core cooling effect is guaranteed. The unsuccessful water injection zone is the area where the total flow rate is less than the critical total flow rate for unsuccessful water injection, and the core cooling effect cannot be guaranteed. The uncertain water injection zone is the area where the total flow rate is between the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection, and the core cooling effect is uncertain.

[0152] It should be noted that if the total water injection flow rate of the primary loop falls into the unsuccessful zone, a prompt message can be output to suggest that more nuclear power plant systems or equipment be put into operation to increase the water injection flow rate of the primary loop; if the total water injection flow rate of the primary loop falls into the successful zone, a prompt message can be output to stop water injection; if the total water injection flow rate of the primary loop falls into the uncertain zone, a prompt message can be output to conduct on-site observation, and then corresponding operations can be performed based on the observation results.

[0153] In some implementations, firstly, based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection, the total water injection flow rate control area of ​​the primary loop is divided into three parts: a successful water injection zone, an unsuccessful water injection zone, and an uncertain water injection zone. Then, it is determined which zone the total water injection flow rate of the primary loop falls into, and the total water injection flow rate of the primary loop is controlled accordingly.

[0154] In other embodiments, the total water injection flow rate of the first loop is compared with these two total flow rates. If the total water injection flow rate of the first loop is greater than the critical total flow rate for successful water injection, then the water injection of the first loop is determined to be successful.

[0155] If the total water injection flow rate of the first loop is less than the critical flow rate for water injection that will definitely fail, then the water injection of the first loop will definitely fail.

[0156] If the total water injection flow rate of the first loop is between the critical flow rate for a certain degree of success and the critical flow rate for a certain degree of failure, then it is determined that the success of the first loop water injection is uncertain.

[0157] For example, after an accident, when the primary circuit pressure is P prim If the water injection flow rate Q v,in Greater than Q v,in,succ If the water injection flow rate Q is [missing information], then it will definitely succeed. v,in Less than Q v,in,fail If the water injection rate Q is unsuccessful, the injection will fail. v,in In Q v,in,fail With Q v,in,succ Between these two points, it is uncertain whether success will be achieved, that is:

[0158]

[0159] In some embodiments, the steps of obtaining the original enthalpy and residual enthalpy of the reactor core described above include:

[0160] To obtain the total energy of the reactor core, including stored energy, oxidation energy, and decay heat.

[0161] The original enthalpy value is determined by summing the energy stored in the reactor core, the oxidation energy, and the total decay heat energy.

[0162] Obtain the void fraction during reactor core flooding, the volume of the reactor core, and the density of water under saturation conditions;

[0163] The coolant volume when the reactor core is submerged is obtained by multiplying the difference between the cavitation fraction when the reactor core is submerged and the volume of the reactor core.

[0164] The coolant loading amount during reactor core flooding is obtained by multiplying the coolant volume during reactor core flooding by the density of water under saturation.

[0165] Obtain the specific enthalpy of water under the saturated state;

[0166] The residual enthalpy is obtained by multiplying the coolant charge of the submerged core by the enthalpy of water under saturation.

[0167] In this embodiment, firstly, data on stored energy, oxidation energy, and decay heat in the reactor core are collected. These three energies are added together to determine the original enthalpy of the reactor core. Secondly, the void fraction, core volume, and water density under saturation are collected during reactor core flooding. The coolant volume during core flooding is obtained by calculating the difference between the void fraction and the core volume. Multiplying the coolant volume by the water density under saturation yields the coolant charge during core flooding, i.e., the mass of water in the core. Thirdly, the specific enthalpy data of water under saturation is collected. Multiplying the coolant charge of the flooded core by the specific enthalpy of water under saturation yields the residual enthalpy of the reactor core. In other words, by calculating the original and residual enthalpy values, the heat changes in the reactor core can be accurately understood, enabling effective heat management. Furthermore, the above calculation formulas can help operators optimize water injection operations, cooling the core most effectively, thereby improving the primary coolant injection efficiency.

[0168] It should be noted that stored energy can be the heat generated by nuclear fission in a nuclear reactor. Oxidation energy can be the heat generated during the oxidation of the nuclear fuel rod cladding. Decay heat can be the heat released during the decay of radioactive nuclides. Void fraction can be the volume ratio of steam or gas in the reactor core. Coolant charge can be the mass of coolant (usually water) in the reactor core. The specific enthalpy of water at saturation can be the thermal energy of water at saturation temperature and pressure.

[0169] For example, when injecting water into the reactor core in the primary coolant loop, the amount of water injected should be sufficient to submerge the core for the injection to be considered successful. When the core is submerged in coolant, a certain amount of cavitation exists; therefore, the amount of coolant used to submerge the core is:

[0170] m fill =(1-α)V core ρ f

[0171] in,

[0172] α represents the void fraction during reactor core flooding.

[0173] V core The reactor core volume (m³) 3 ),

[0174] ρ f The density of water under saturated conditions (kg / m³) 3 ).

[0175] If the coolant temperature is at its saturation temperature after the reactor core is submerged, then the enthalpy of the water after the reactor core is submerged is:

[0176] E fill =m fill H f

[0177] in,

[0178] m fill The coolant charge (kg) during core flooding.

[0179] H f The specific enthalpy of water under saturated conditions (J / kg).

[0180] For example, suppose a reactor core has a stored energy of 500 J, an oxidation energy of 100 J, a decay heat of 200 J, a void fraction of 0.2, and a core volume of 100 m³. 3 The density of water in a saturated state is 1000 kg / m³. 3 The specific enthalpy of water under saturation is 1800 kJ / kg.

[0181] Calculate the original enthalpy: Original enthalpy = 500J + 100J + 200J = 800J;

[0182] Calculate the coolant volume: Coolant volume = (1 - 0.2) × 100 m³ 3 =80m 3 ;

[0183] Calculate the coolant charge: Coolant charge = 80m 3 ×1000kg / m 3 =80000kg;

[0184] Calculate the residual enthalpy: Residual enthalpy = 80000kg × 1800kJ / kg = 144000000kJ.

[0185] These calculations allow operators to understand the energy changes in the reactor core and adjust water injection operations accordingly to ensure the safety and stability of the core.

[0186] In some embodiments, the steps described above for obtaining the total energy of the reactor core, including energy storage, oxidation energy, and decay heat, include:

[0187] Obtain the total mass and specific heat of the reactor core;

[0188] The heat capacity is obtained by multiplying the total mass of the reactor core by the specific heat of the core.

[0189] The energy storage capacity of the reactor core is obtained by multiplying the heat capacity by the difference between the current temperature of the reactor core and the saturation temperature of the reactor core.

[0190] Obtain the total mass of metallic zirconium in the reactor core, the molar mass of zirconium, the oxidation ratio of metallic zirconium in the reactor core, and the energy released by the oxidation of one mole of metallic zirconium.

[0191] The number of moles of zirconium is obtained by dividing the total mass of metallic zirconium in the reactor core by the molar mass of zirconium.

[0192] The oxidation energy is obtained by multiplying the number of moles of zirconium by the oxidation ratio of metallic zirconium in the reactor core and the energy released by the oxidation of one mole of metallic zirconium.

[0193] Obtain the power linearity coefficient, power exponential coefficient, and the time interval from reactor shutdown to the start of water injection;

[0194] Based on the power linearity coefficient, the power exponential coefficient, and the time interval from reactor shutdown to the start of water injection, a formula for calculating the total decay heat energy is determined; wherein, the formula for calculating the total decay heat energy is:

[0195]

[0196] Where α is the power linearity coefficient, β is the power exponential coefficient, 0 < β < 1, t start E is the interval between reactor shutdown and water injection. decay This represents the total energy of decay heat.

[0197] Substituting the critical time for successful water injection or the critical time for unsuccessful water injection into the calculation formula for the total decay heat energy, the total decay heat energy is obtained.

[0198] In this embodiment, firstly, the core's heat capacity is calculated using the total core mass and specific heat. Then, the core's stored energy is obtained by multiplying the heat capacity by the difference between the current core temperature and the saturation temperature. The number of moles of zirconium is obtained by dividing the total mass of zirconium in the core by its molar mass. Next, the oxidation energy is obtained by multiplying the number of moles of zirconium by the oxidation ratio and the energy released per mole of zirconium oxidation. Using given power linearity coefficients, power exponential coefficients, the time interval from shutdown to the start of water injection, and the primary loop water injection duration, the total decay heat energy is determined using the formula for calculating total decay heat energy. That is, determining the reactor core's stored energy, oxidation energy, and total decay heat energy, through accurate energy calculations, helps prevent the core temperature from continuously rising and further deterioration of a nuclear accident, improving the safety of the nuclear reactor. Simultaneously, it assists operators in core cooling and improves the efficiency of primary loop water injection.

[0199] It should be noted that heat capacity can be the heat absorbed or released by a substance when its temperature changes, usually expressed as the product of mass, specific heat, and temperature change. Stored energy can be the heat stored in the reactor core due to temperature changes. Oxidation energy can be the energy released during the oxidation of zirconium. Total decay heat energy can be the total heat released during the decay of a radioactive nuclide. The power linearity coefficient can be a coefficient linearly related to the reactor power, used to calculate decay heat. The power exponent coefficient can be a coefficient related to the reactor power exponent, used to calculate decay heat. The shutdown-to-water injection interval can be the time interval between reactor shutdown and the start of water injection.

[0200] For example, in the event of a core loss-of-coolant accident at a nuclear power plant, the primary coolant exists in both liquid and gas phases simultaneously, and the primary coolant and the core as a whole are in a saturated state. Water injected into the core will cool the core to its saturation temperature and absorb the core's stored energy, core oxidation energy, and core decay heat. Simultaneously, some of the coolant will vaporize into saturated steam and be discharged from the core. In the event of a nuclear power plant accident, the operator can read the primary coolant pressure in the main control room; therefore, this patent assumes that the known primary coolant pressure is P. prim If the primary coolant injection can submerge and cool the reactor core, the core temperature can be reduced to the primary coolant pressure P. prim The corresponding saturation temperature.

[0201] During the core cooling process, the energy stored in the reactor core is:

[0202] E store =m core C p,core (T core -T sat )

[0203] in,

[0204] m core The total mass of the reactor core (kg)

[0205] C p,core The specific heat of the reactor core (J / (kg·K))

[0206] T core The current core temperature (K)

[0207] T sat For P prim Saturation temperature (K) under pressure.

[0208] After primary coolant injection is implemented, the coolant enters the reactor core and comes into contact with the metallic zirconium, which may trigger an oxidation reaction and release oxidation energy. This portion of the core oxidation energy also needs to be carried away by the cooling water. Therefore, the oxidation energy during the core cooling process is:

[0209]

[0210] in,

[0211] m Zr This represents the total mass (kg) of metallic zirconium in the reactor core.

[0212] M Zr Here is the molar mass of zirconium (kg / mol).

[0213] R ox This represents the oxidation ratio of metallic zirconium in the reactor core.

[0214] E Zr The energy released per mole of zirconium oxide (J / mol).

[0215] After the reactor is shut down, the decay of fission products generates heat, and the decay heat power (W) can be considered as a function of time:

[0216] q decay (t)=αt -β

[0217] in,

[0218] α is the power linearity coefficient.

[0219] β is the power exponent coefficient, 0 < β < 1.

[0220] Assuming a downtime of t start Start filling with water, the filling time is t inj Then the total decay heat energy (J) after water injection is:

[0221]

[0222] Please see Figure 2 This application also provides a primary loop water injection device that can implement the above-described primary loop water injection method. The device includes:

[0223] The enthalpy acquisition module 201 is used to acquire the original enthalpy and the remaining enthalpy of the reactor core; the original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat, and the stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core; the remaining enthalpy is the enthalpy after successful water injection into the reactor core, and successful water injection into the reactor core indicates that the reactor core has been submerged in coolant and cooled to the saturation temperature;

[0224] The time acquisition module 202 is used to acquire the critical time for successful water injection and the critical time for unsuccessful water injection corresponding to the primary loop of the reactor core.

[0225] The determining module 203 is used to determine the critical total flow rate for successful water injection of the primary loop based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core; and to determine the critical total flow rate for unsuccessful water injection of the primary loop based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop.

[0226] The control module 204 is used to control the total water injection flow of the primary loop based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection.

[0227] The specific implementation method of the primary loop water injection device is basically the same as the specific implementation method of the primary loop water injection described above, and will not be repeated here.

[0228] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the aforementioned one-loop water injection method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0229] Please see Figure 3 , Figure 3 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes:

[0230] The processor 301 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0231] The memory 302 can be implemented as a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 302 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 302 and is called and executed by the processor 301 using the first-loop water injection method of the embodiments of this application.

[0232] Input / output interface 303 is used to implement information input and output;

[0233] The communication interface 304 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0234] Bus 305 transmits information between various components of the device (e.g., processor 301, memory 302, input / output interface 303, and communication interface 304);

[0235] The processor 301, memory 302, input / output interface 303, and communication interface 304 are connected to each other within the device via bus 305.

[0236] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned primary-loop water injection method.

[0237] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0238] The primary loop water injection method, device, electronic equipment, and storage medium provided in this application embodiment obtain the original enthalpy and residual enthalpy of the reactor core. The original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat. The stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core. The residual enthalpy is the enthalpy after successful water injection into the reactor core. Successful water injection into the reactor core indicates that the reactor core is submerged in coolant and cooled to the saturation temperature. Secondly, the method obtains the original enthalpy and residual enthalpy of the reactor core's stored energy. The reactor core's primary loop is divided into two parts: a critical time for successful water injection and a critical time for unsuccessful water injection. Then, based on the successful water injection critical time, the original enthalpy, the remaining enthalpy, and the energy conservation principle of the reactor core, the critical total flow rate for successful water injection in the primary loop is determined. Similarly, based on the unsuccessful water injection critical time, the original enthalpy, the remaining enthalpy, and the energy conservation principle of the primary loop, the critical total flow rate for unsuccessful water injection in the primary loop is determined. Finally, the total water injection flow rate of the primary loop is controlled based on these two values. In other words, the critical total flow rate for unsuccessful water injection and the critical total flow rate for successful water injection in the primary loop are determined based on the critical time, the original enthalpy, and the remaining enthalpy, thereby controlling the total water injection flow rate of the primary loop. In this way, by controlling the total water injection flow rate of the primary loop, the reactor core is effectively cooled, preventing further deterioration of a nuclear accident and improving the efficiency of primary loop water injection.

[0239] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0240] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0241] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0242] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0243] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0244] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0245] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0246] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0247] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0248] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0249] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for water injection in the primary loop of a nuclear reactor, characterized in that, The method includes: Obtain the original enthalpy and remaining enthalpy of the reactor core; the original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat, wherein the stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core; the remaining enthalpy is the enthalpy after successful water injection into the reactor core, where successful water injection indicates that the reactor core is submerged in coolant and cooled to the saturation temperature; Obtain the critical time for successful water injection and the critical time for unsuccessful water injection corresponding to the primary loop of the reactor core; Based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core, the critical total flow rate for successful water injection in the primary loop is determined; and based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop, the critical total flow rate for unsuccessful water injection in the primary loop is determined. The total water injection flow rate of the first loop is controlled based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection. The method for determining the total energy of the decay heat includes: Obtain the power linearity coefficient, power exponential coefficient, time interval from reactor shutdown to start water injection, and water injection duration of the primary loop; The total decay heat energy is determined based on the power linearity coefficient, the power exponential coefficient, the time interval from reactor shutdown to the start of water injection, the water injection duration of the primary loop, and the critical time for successful water injection; or, The total decay heat energy is determined based on the power linearity coefficient, the power exponential coefficient, the time interval from reactor shutdown to the start of water injection, the water injection duration of the primary loop, and the critical time for unsuccessful water injection.

2. The method according to claim 1, characterized in that, The steps of determining the critical total flow rate for successful water injection of the reactor core based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core; and determining the critical total flow rate for unsuccessful water injection of the primary loop based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop, include: Based on the principle of energy conservation in the reactor core, the energy conservation calculation formula for the reactor core is determined; the energy conservation calculation formula is as follows: AND in -AND out =And fill -(AND store +E ox +E decay ) Among them, E in E is the injection enthalpy of the reactor core. out E is the effluent enthalpy of the reactor core. fill E is the remaining enthalpy value. store +E ox +E decay The original enthalpy value; An equivalent water injection method is used to determine the formulas for calculating the injection enthalpy and the outflow enthalpy of the reactor core; both the injection enthalpy and outflow enthalpy calculation formulas include the water injection duration of the primary loop and the total water injection flow rate of the primary loop. Based on the energy conservation calculation formula, the injection enthalpy calculation formula, and the outflow enthalpy calculation formula, the total water injection flow rate calculation formula for the primary loop is determined. Substituting the critical time for successful water injection, the original enthalpy value, and the remaining enthalpy value into the formula for calculating the total water injection flow rate, the critical total water injection flow rate for successful water injection of the reactor core is obtained. Substituting the critical time of unsuccessful water injection, the original enthalpy value, and the remaining enthalpy value into the formula for calculating the total water injection flow rate, the critical total flow rate of the reactor core in case of unsuccessful water injection is obtained.

3. The method according to claim 2, characterized in that, The steps for determining the injection enthalpy and effluent enthalpy calculation formulas of the reactor core using the equivalent water injection method include: Obtain the equivalent water injection specific enthalpy and equivalent water injection density of the primary loop, as well as the coolant charge and steam specific enthalpy under saturated conditions when the reactor core is submerged, wherein the saturated state is the state corresponding to the saturation temperature; The formula for calculating the injection enthalpy is determined based on the equivalent injection density and the equivalent injection ratio enthalpy; the formula for calculating the injection enthalpy is as follows: E in =Q v,in ρ in,eq H in,eq t inj The formula for calculating the outflow enthalpy is determined based on the equivalent water injection density, the coolant charge, and the specific enthalpy of the steam; the formula for calculating the outflow enthalpy is as follows: E out =Q m,out H g t inj in, Q v,in ρ is the total flow rate of the primary loop water injection. in,eq Let m be the equivalent water injection density of the first loop. fill The coolant charge (t) during reactor core flooding. inj Q is the water injection duration of the first loop. m,out H is the mass flow rate of the reactor core outflow. g E is the specific enthalpy of vapor under saturated conditions. in H is the injection enthalpy value. in,eq The equivalent water injection ratio enthalpy of the first loop is given.

4. The method according to claim 3, characterized in that The step of determining the total injection flow rate of the primary loop based on the energy conservation calculation formula, the injection enthalpy calculation formula, and the outflow enthalpy calculation formula includes: Substituting the injection enthalpy calculation formula and the outflow enthalpy calculation formula into the energy conservation calculation formula, the total injection flow rate of the first loop is calculated; the total injection flow rate of the first loop is calculated as follows: Among them, Q v,in The total water injection flow rate of the first loop is given.

5. The method according to claim 1, wherein The step of controlling the total water injection flow rate of the primary loop based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection includes: Based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection, the system is divided into a successful water injection zone, an unsuccessful water injection zone, and an uncertain water injection zone. The successful water injection zone is the area where the total water injection flow rate of the first loop is greater than the critical total flow rate for successful water injection. The unsuccessful water injection zone is the area where the total water injection flow rate of the first loop is less than the critical total flow rate for unsuccessful water injection. The uncertain water injection zone is the area where the total water injection flow rate of the first loop is less than the critical total flow rate for successful water injection but greater than the critical total flow rate for unsuccessful water injection. The total water injection flow rate of the first loop is controlled to fall into the successful water injection zone.

6. The method according to claim 1, characterized in that, The steps for obtaining the original enthalpy and residual enthalpy of the reactor core include: To obtain the total energy of the reactor core, including stored energy, oxidation energy, and decay heat. The original enthalpy value is determined by summing the energy stored in the reactor core, the oxidation energy, and the total decay heat energy. Obtain the void fraction during reactor core flooding, the volume of the reactor core, and the density of water under saturation conditions; The coolant volume when the reactor core is submerged is obtained by multiplying the difference between the cavitation fraction when the reactor core is submerged and the volume of the reactor core. The coolant loading amount during reactor core flooding is obtained by multiplying the coolant volume during reactor core flooding by the density of water under saturation. Obtain the specific enthalpy of water under the saturated state; The residual enthalpy is obtained by multiplying the coolant charge of the submerged core by the enthalpy of water under saturation.

7. The method according to claim 6, characterized in that, The steps for obtaining the total energy of the reactor core, including energy storage, oxidation energy, and decay heat, include: Obtain the total mass and specific heat of the reactor core; The heat capacity is obtained by multiplying the total mass of the reactor core by the specific heat of the core. The energy storage capacity of the reactor core is obtained by multiplying the heat capacity by the difference between the current temperature of the reactor core and the saturation temperature of the reactor core. Obtain the total mass of metallic zirconium in the reactor core, the molar mass of zirconium, the oxidation ratio of metallic zirconium in the reactor core, and the energy released by the oxidation of one mole of metallic zirconium. The number of moles of zirconium is obtained by dividing the total mass of metallic zirconium in the reactor core by the molar mass of zirconium. The oxidation energy is obtained by multiplying the number of moles of zirconium by the oxidation ratio of metallic zirconium in the reactor core and the energy released by the oxidation of one mole of metallic zirconium. The formula for calculating the total decay heat energy is determined based on the power linearity coefficient, the power exponential coefficient, the time interval from reactor shutdown to the start of water injection, and the water injection duration of the primary loop; wherein, the formula for calculating the total decay heat energy is: Where α is the power linearity coefficient, β is the power exponential coefficient, 0 < β < 1, t start E is the interval between reactor shutdown and water injection. decay The total energy of decay heat, t inj The water injection duration of the first loop; Substituting the critical time for successful water injection or the critical time for unsuccessful water injection into the calculation formula for the total decay heat energy, the total decay heat energy is obtained.

8. A primary-loop water injection device, characterized in that, The device includes: An enthalpy acquisition module is used to acquire the original enthalpy and remaining enthalpy of the reactor core. The original enthalpy includes the total energy of the reactor core's stored energy, oxidation energy, and decay heat. The stored energy is determined based on the current temperature of the reactor core and the saturation temperature corresponding to the primary loop pressure of the reactor core. The remaining enthalpy is the enthalpy after successful water injection into the reactor core. Successful water injection into the reactor core indicates that the reactor core has been submerged in coolant and cooled to the saturation temperature. The time acquisition module is used to acquire the critical time for successful water injection and the critical time for unsuccessful water injection corresponding to the primary loop of the reactor core. The determining module is used to determine the critical total flow rate for successful water injection of the primary loop based on the critical time for successful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the reactor core; and to determine the critical total flow rate for unsuccessful water injection of the primary loop based on the critical time for unsuccessful water injection, the original enthalpy value, the remaining enthalpy value, and the energy conservation principle of the primary loop. The control module is used to control the total water injection flow of the first loop based on the critical total flow rate for successful water injection and the critical total flow rate for unsuccessful water injection. The enthalpy acquisition module is also used for: Obtain the power linearity coefficient, power exponential coefficient, time interval from reactor shutdown to start water injection, and water injection duration of the primary loop; The total decay heat energy is determined based on the power linearity coefficient, the power exponential coefficient, the time interval from reactor shutdown to the start of water injection, the water injection duration of the primary loop, and the critical time for successful water injection; or, The total decay heat energy is determined based on the power linearity coefficient, the power exponential coefficient, the time interval from reactor shutdown to the start of water injection, the water injection duration of the primary loop, and the critical time for unsuccessful water injection.

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