Mass evaporation rate calculation method and device of boiling environment and readable medium

Abstract

The invention provides a mass evaporation rate calculation method and device of a boiling environment and a readable medium. The mass evaporation rate calculation method comprises the following steps: carrying out node division on a pressurized water reactor coolant system; for each node, whether the dirt thickness of the current node is larger than a critical value or not is judged, if yes, the current node is the dirt surface, the mass evaporation rate of the node is calculated based on a porous sediment boiling module, and if not, the current node is the clean cladding surface, and the mass evaporation rate of the node is calculated based on the boiling heat flow and the mass evaporation module. According to the method, clean and dirty cladding surfaces are respectively considered, a group of mass evaporation rate calculation formulas are established, the mass evaporation rates of the reactor core and each node of the steam generator are calculated in detail according to information input by a user, and the calculated mass evaporation rates are more accurate and accord with actual scenes.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of nuclear reactors, and in particular to a method for calculating the mass evaporation rate in a boiling environment, a calculation device and a readable medium. Background Art

[0002] When the reactor is in operation, the corrosion products (nickel, iron, etc.) on the pipes of the pressurized water reactor coolant system of the pressurized water reactor nuclear power plant will be released into the coolant and deposited on the high heat flux density fuel assembly where supercooled nucleate boiling occurs to form scale. Boron and lithium hydroxides accumulate in the pores of the scale. When boron accumulates to a certain extent, it will precipitate on the scale, which will cause the power of the upper part of the fuel assembly to decrease, and the power peak will move downward, that is, the scale-induced axial power shift (CIPS) will occur. If the scale deposition is thick in the local position, the coolant will not be able to flow through the scale and cool the surface of the fuel cladding, which will cause the temperature of the fuel cladding to be too high. If the fuel cladding is at a very high temperature for a long time, it will accelerate the corrosion and failure of the fuel cladding, resulting in scale-induced localized cladding corrosion (CILC).

[0003] CIPS and CILC will affect the safety and economy of reactor operation. The risk assessment of reactor core fouling is one of the important issues of nuclear safety in the future. The mass evaporation rate refers to the mass evaporated per unit area per unit time. The accumulation of fouling will reduce the heat transfer efficiency, thereby reducing the mass evaporation rate. The mass evaporation rate is one of the important indicators for assessing the risk of reactor core fouling. Therefore, it is necessary to establish a mass evaporation rate calculation method for fouling risk analysis to assess CIPS and CILC risks. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a mass evaporation rate calculation method, a calculation device and a readable medium in a boiling environment, so as to solve the current lack of a mass evaporation rate calculation method for fouling risk analysis calculation.

[0005] To solve the above technical problems, the present invention provides a method for calculating the mass evaporation rate in a boiling environment, comprising: dividing a pressurized water reactor coolant system into nodes; for each node, determining whether the dirt thickness of the current node is greater than a critical value, if so, the current node is a dirty surface, and the mass evaporation rate of the node is calculated based on a porous sediment boiling module; if not, the current node is a clean cladding surface, and the mass evaporation rate of the node is calculated based on a boiling heat flow and a mass evaporation module.

[0006] Optionally, calculating the mass evaporation rate of the node based on the porous sediment boiling module includes: dividing the grid nodes in sequence from the dirt surface to the wall surface; setting the interior of the dirt to a capillary porous structure, and setting the parameter boundary value of the dirt surface; constructing the energy equation and heat transfer equation of the dirt, and inputting the parameter boundary value of the dirt surface into the energy equation and the heat transfer equation to calculate the mass evaporation rate of each grid node.

[0007] Optionally, the parameter boundary values ​​of the dirt surface include the temperature of the dirt surface and the mass evaporation rate gradient of the dirt surface.

[0008] Optionally, calculating the mass evaporation rate of each grid node includes: calculating the mass evaporation rate of the dirt surface based on the heat flux transferred by heat conduction on the dirt surface and the heat flux on the wall; calculating the temperature gradient of each grid node based on the energy equation, and calculating the temperature of each grid node based on the temperature of the dirt surface and the temperature gradient; calculating the mass evaporation rate gradient of each grid node based on the heat transfer equation and the temperature of each grid node; calculating the mass evaporation rate of each grid node based on the mass evaporation rate of the dirt surface, the mass evaporation rate gradient of the dirt surface and the mass evaporation rate gradient of each grid node.

[0009] Optionally, the mass evaporation rate of the dirt surface is calculated by the following formula:

[0010]

[0011] in, is the vapor phase enthalpy of the dirt surface, is the liquid phase enthalpy of the dirt surface, is the heat flow transferred by heat conduction on the dirt surface, is the heat flux on the wall, and G(1) is the mass evaporation rate of the dirt surface.

[0012] Optionally, the energy equation is:

[0013]

[0014] in, is the heat flux transferred by heat conduction at the n+1th grid node, is the thermal conductivity of the dirt, is the temperature gradient of the n+1th grid node.

[0015] Optionally, the heat transfer equation is:

[0016]

[0017] in, is the volume heat transfer coefficient of phase change, is the saturation temperature of the liquid inside the dirt, is the temperature of the grid node, is the latent heat of vaporization, is the mass evaporation rate gradient.

[0018] Optionally, calculating the mass evaporation rate of the node based on the boiling heat flux and mass evaporation module includes: calculating the wall temperature considering only forced convection heat transfer and the wall temperature at the boiling starting point; judging whether the wall temperature considering only forced convection heat transfer is greater than the wall temperature at the boiling starting point, and if so, calculating the heat flux density component through the supercooled boiling equation; and calculating the mass evaporation rate according to the heat flux density component and the latent heat of vaporization.

[0019] Optionally, the wall temperature considering only forced convection heat transfer is calculated by the following formula:

[0020]

[0021] in, is the wall temperature considering only forced convection heat transfer, is the fluid temperature, is the forced convection heat transfer coefficient, and q is the heat flux density.

[0022] Optionally, the boiling starting point wall temperature is calculated by the following formula:

[0023]

[0024] in, is the wall temperature at the boiling starting point, is the fluid temperature, is the heat flux component at the boiling starting point, is the heat transfer coefficient at the boiling onset.

[0025] Optionally, the subcooled boiling equation is:

[0026]

[0027] Where q is the heat flux, is the saturated boiling heat flux component, is the heat flux component at the boiling starting point, is the forced convection heat flux component.

[0028] Alternatively, the mass evaporation rate is calculated by the following formula:

[0029]

[0030] in, is the mass evaporation rate, is the latent heat of vaporization.

[0031] Optionally, the method further includes: if the wall temperature considering only forced convection heat transfer is less than or equal to the wall temperature at the boiling starting point, the mass evaporation rate is zero.

[0032] To solve the above technical problems, the present invention provides a computing device, comprising: at least one processor; and at least one memory on which instructions are stored, and when the instructions are executed by the at least one processor individually or collectively, the computing device executes the method as described above.

[0033] To solve the above technical problem, the present invention provides a computer-readable medium, on which instructions are stored. When the instructions are executed individually or collectively by at least one processor of a computing device, the computing device executes the above method.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] The mass evaporation rate calculation method, calculation device and readable medium of the boiling environment of the present invention respectively consider the clean and dirty cladding surfaces, establish a set of mass evaporation rate calculation formulas, and calculate the mass evaporation rate of each node of the core and steam generator in detail according to user input information. The calculated mass evaporation rate is more accurate and conforms to the actual scenario. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0037] Figure 1 The figure is a flow chart of a method for calculating the mass evaporation rate in a boiling environment according to an embodiment of the present disclosure.

[0038] Figure 2 yes Figure 1 Flow chart of an embodiment of step S3 in FIG.

[0039] Figure 3 It is a schematic diagram of the node division of the dirt grid according to an embodiment of the present disclosure.

[0040] Figure 4 Schematic diagram of a capillary porous body structure according to an embodiment of the present disclosure.

[0041] Figure 5 yes Figure 1 Flow chart of an embodiment of step S4 in FIG.

[0042] Figure 6 is a system block diagram of a computing device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0044] The present invention provides a method for calculating the mass evaporation rate in a boiling environment. The method considers the clean and dirty cladding surfaces respectively, establishes a set of mass evaporation rate calculation formulas, and calculates the mass evaporation rate of each node of the core and the steam generator in detail according to user input information, which is used for CIPS and CILC risk analysis.

[0045] Figure 1 FIG. 1 is a flow chart of a method for calculating the mass evaporation rate of a boiling environment according to an embodiment of the present disclosure. Figure 1 As shown, the mass evaporation rate calculation method 100 of a boiling environment includes:

[0046] Step S1: divide the pressurized water reactor coolant system into nodes.

[0047] The reactor coolant system in a nuclear power plant is also called the primary circuit system. The coolant system consists of a reactor coolant pump, a reactor and a steam generator, and corresponding pipelines. For the reactor coolant system, the core and steam generator are divided into model calculation nodes according to the calculation requirements.

[0048] Step S2: for each node, determine whether the dirt thickness of the current node is greater than the critical value, if yes, proceed to step S3, if yes, proceed to step S4.

[0049] Among them, the critical value can be set as needed, and this application does not impose any restrictions on this.

[0050] Step S3: The current node is a fouled surface, and the mass evaporation rate of the node is calculated based on the porous sediment boiling module.

[0051] Taking the critical value of 500nm as an example, it is determined whether the dirt thickness of the current node is greater than 500nm. If it is greater, the current node is a dirt surface, and the mass evaporation rate of the node is calculated based on the porous sediment boiling module.

[0052] Figure 2 yes Figure 1 Flow chart of step S3 in an embodiment. Figure 2 As shown, step S3 includes:

[0053] Step S31: Divide grid nodes sequentially from the fouling surface towards the wall surface.

[0054] Figure 3 It is a schematic diagram of fouling grid node division according to an embodiment of the present disclosure. As Figure 3 shown, the grid is evenly divided according to the given fouling thickness δ, and the grid size is dx. Nodes are sequentially divided from the fouling surface (close to the fluid side) towards the wall surface, denoted as x(1), x(2), …, x(n), x(n + 1) respectively. x(n) represents the nth fouling layer. In particular, x(1) represents the first fouling layer, also known as the fouling surface. Among them is the heat flux of the wall surface, transferring in the fluid direction, is the heat flux of the fluid.

[0055] Step S32: Set the interior of the fouling as a capillary porous structure and set the parameter boundary values of the fouling surface.

[0056] The present disclosure sets the interior of the fouling as a capillary porous structure. Figure 4 It is a schematic diagram of the capillary porous structure according to an embodiment of the present disclosure. As Figure 4 shown, there is a group of interconnected pores in the porous body of this structure. These pores or porous bodies can be divided into clusters of vertical pores and interconnected side pores. Assume that the larger vertical pores (r > critical effective radius R*) are filled with vapor, and the smaller pores (r < R*) are filled with liquid. For the side pores with a critical effective radius of R*, a dynamic equilibrium state is maintained between the liquid phase and the vapor.

[0057] Parameter boundary values refer to the boundaries of the effective range of input parameters and the values near them. These values usually include the minimum value, maximum value of the parameter, and the neighboring values of these values. For example, if the value range of a parameter is [1, 100], then the minimum value is 1, and the maximum value is 100. Then the effective boundary values are 1 and 100. The invalid boundary values are 0 and 101. The neighboring values are 2 and 99. Boundary value analysis is based on the assumption that instances often occur near the boundaries of the input range rather than in the middle. Optionally, the parameter boundary values of the fouling surface include but are not limited to the temperature of the fouling surface 、critical pore radius 、critical pore radius gradient 、mass evaporation rate gradient .

[0058] Step S33: Construct the energy equation and heat transfer equation of the fouling, and input the parameter boundary values of the fouling surface into the energy equation and heat transfer equation to calculate the mass evaporation rate of each grid node.

[0059] Optionally, calculating the mass evaporation rate of each grid node includes:

[0060] Step S331: Calculate the mass evaporation rate of the dirt surface according to the heat flux transferred by heat conduction on the dirt surface and the heat flux on the wall.

[0061] Mass evaporation rate of dirt surface According to "the heat flux transferred by heat conduction on the dirt surface must be equivalent to the heat flux on the wall " is obtained, and their mutual relationship is as follows shown.

[0062] (1)

[0063] Where: —Vapor phase enthalpy of dirt surface, in J / kg, where v represents the vapor phase;

[0064] —Enthalpy of liquid phase on dirt surface, in J / kg, where l represents liquid phase;

[0065] The heat flux transferred by heat conduction on the dirt surface, in W / m 2 .

[0066] Step S332: Calculate the temperature gradient of each grid node according to the energy equation, and calculate the temperature of each grid node according to the temperature of the dirt surface and the temperature gradient;

[0067] The present application considers that for steady-state conditions, the energy transferred out of the fouling layer by heat conduction is equal to the net energy transferred into the fouling layer by convection of liquid and steam. The energy conservation equation is expressed as As shown. Combined with Fourier's law, as shown in the relation As shown:

[0068] (2)

[0069] Where: —Heat flow under the heat conduction of the n+1th layer, in W / m 2 ;

[0070] is the heat flux under the heat conduction of the nth layer, in W / m 2 ;

[0071] is the mass evaporation rate of the n+1th layer, in kg / m 2 ·s;

[0072] is the mass evaporation rate of the nth layer, in kg / m 2 ·s;

[0073] is the vapor phase enthalpy of the dirt surface, is the liquid phase enthalpy of the dirt surface.

[0074] (3)

[0075] (4)

[0076] Where: k is the thermal conductivity of the n+1th layer, and the subscripts crud, l, v, and s represent the dirt layer, the liquid phase in the dirt layer, the vapor phase in the dirt layer, and the solid phase in the dirt layer, respectively.

[0077] —porosity of the n+1th layer;

[0078] —The proportion of the liquid phase in the n+1th layer to the dirt layer;

[0079] is the temperature gradient of the n+1th layer.

[0080] At a known dirt surface temperature and temperature gradient In the case of and Enter the formula , get the temperature of the second layer ,according to and The temperature of the third layer can be calculated , and so on, the temperature of the n+1th layer can be calculated.

[0081] Step S333: Calculate the mass evaporation rate gradient of each grid node according to the heat transfer equation and the temperature of each grid node;

[0082] The equation for heat transfer between phases in the gap is as follows:

[0083] (5)

[0084] in, is the volume heat transfer coefficient of phase change, is the saturation temperature of the liquid inside the dirt, is the temperature of the grid node, is the latent heat of vaporization, is the mass evaporation rate gradient.

[0085] Step S334: Calculate the mass evaporation rate of each grid node according to the mass evaporation rate of the dirt surface, the mass evaporation rate gradient of the dirt surface and the mass evaporation rate gradient of each grid node.

[0086] Evaporation rate according to surface mass , mass evaporation rate gradient of dirt surface and the n+1 layer mass evaporation rate gradient The mass evaporation rate of the n+1 layer can be calculated. For example, the surface mass evaporation rate and mass evaporation rate gradient enter = , output ; Then according to the mass evaporation rate and the calculated mass evaporation rate gradient Calculate , and so on, we get the mass evaporation rate of the n+1th layer .

[0087] When the solution of the relation (5) converges, it is determined whether the evaporation point is reached. If so, the calculation is terminated.

[0088] Step S4: The current node is a clean cladding surface, and the mass evaporation rate of the node is calculated based on the boiling heat flux and mass evaporation module.

[0089] Taking the critical value of 500nm as an example, we determine whether the dirt thickness of the current node is greater than 500nm. If it is less than or equal to 500nm, the current node is a clean shell surface. The mass evaporation rate of the node is calculated based on the boiling heat flux and mass evaporation module.

[0090] Figure 5 yes Figure 1 Flow chart of step S4 in an embodiment. Figure 4 As shown, step S4 includes:

[0091] Step S41: Calculate the wall temperature considering only forced convection heat transfer.

[0092] Alternatively, the wall temperature considering only forced convection heat transfer can be calculated using the following formula:

[0093] (6)

[0094] in, is the wall temperature considering only forced convection heat transfer, is the fluid temperature, is the forced convection heat transfer coefficient, and q is the heat flux density.

[0095] Step S42: Calculate the wall temperature at the boiling starting point.

[0096] (7)

[0097] in, is the wall temperature at the boiling starting point, is the fluid temperature, is the heat flux component at the boiling starting point, is the heat transfer coefficient at the boiling onset.

[0098] Step S43: Determine whether the wall temperature considering only forced convection heat transfer is greater than the wall temperature at the boiling starting point. If yes, proceed to step S44; if not, proceed to step S46.

[0099] Step S44: Calculate the heat flux component by the subcooled boiling equation.

[0100] (8)

[0101] Where q is the heat flux, is the saturated boiling heat flux component, is the heat flux component at the boiling starting point, is the forced convection heat flux component.

[0102] Step S45: Calculate the mass evaporation rate according to the heat flux density component and the latent heat of vaporization.

[0103] (9)

[0104] in, is the mass evaporation rate, is the latent heat of vaporization.

[0105] Step S46: The mass evaporation rate is zero.

[0106] Right now, .

[0107] The present application also includes a computing device, including a memory and a processor, wherein the memory is used to store instructions executable by the processor; the processor is used to execute the instructions to implement the mass evaporation rate calculation method of the boiling environment described above.

[0108] Figure 6 is a system block diagram of a computing device according to an embodiment of the present disclosure. Figure 6As shown, the computing device 600 may include an internal communication bus 601, a processor 602, a read-only memory (ROM) 603, a random access memory (RAM) 604, and a communication port 605. When applied to a personal computer, the computing device 600 may also include a hard disk 606. The internal communication bus 601 can realize data communication between the components of the computing device 600. The processor 602 can make judgments and issue prompts. In some embodiments, the processor 602 can be composed of one or more processors. The communication port 605 can realize data communication between the computing device 600 and the outside. In some embodiments, the computing device 600 can send and receive information and data from the network through the communication port 605. The computing device 600 may also include different forms of program storage units and data storage units, such as a hard disk 606, a read-only memory (ROM) 603 and a random access memory (RAM) 604, which can store various data files used for computer processing and / or communication, and possible program instructions executed by the processor 602. The processor executes these instructions to implement the main part of the method. The processing result of the processor is transmitted to the user device through the communication port and displayed on the user interface.

[0109] The above-mentioned operation method can be implemented as a computer program, stored in the hard disk 606, and loaded into the processor 602 for execution, so as to implement the mass evaporation rate calculation method of the boiling environment of the present application.

[0110] The present application also includes a computer-readable medium storing a computer program code, which, when executed by a processor, implements the mass evaporation rate calculation method for a boiling environment as described above.

[0111] When the mass evaporation rate calculation method of a boiling environment is implemented as a computer program, it can also be stored in a computer-readable storage medium as a product. For example, a computer-readable storage medium may include, but is not limited to, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic strip), an optical disk (e.g., a compact disk (CD), a digital versatile disk (DVD)), a smart card, and a flash memory device (e.g., an electrically erasable programmable read-only memory (EPROM), a card, a stick, a key drive). In addition, the various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media (and / or storage media) that can store, contain and / or carry code and / or instructions and / or data.

[0112] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0113] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0114] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0115] As shown in this application, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0116] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0117] Some aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor may be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, various aspects of the present application may be represented as computer products located in one or more computer-readable media, which include computer-readable program codes. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes ...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs ...), smart cards, and flash memory devices (e.g., cards, sticks, key drives ...).

[0118] A computer-readable medium may include a propagated data signal containing computer program code, such as in baseband or as part of a carrier wave. The propagated signal may have a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium, which may be connected to an instruction execution system, device or apparatus to communicate, propagate or transmit a program for use. The program code on the computer-readable medium may be propagated via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above mediums.

[0119] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of the present application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the subject of the present application requires more features than the features mentioned. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.

[0120] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used for the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification are approximate values, which can be changed according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the method of general digit retention. Although the numerical domains and parameters used to confirm the breadth of the range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0121] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present application, they will fall within the scope of the present application.

Claims

1. A method for calculating the mass evaporation rate of a boiling environment, characterized in that: include: Node division of the PWR coolant system; For each node, determine whether the dirt thickness of the current node is greater than the critical value. If so, the current node is a dirty surface, and the mass evaporation rate of the node is calculated based on the porous sediment boiling module. If not, the current node is a clean cladding surface, and the mass evaporation rate of the node is calculated based on the boiling heat flow and mass evaporation module.

2. The mass evaporation rate calculation method according to claim 1, characterized in that: The mass evaporation rate of the node is calculated based on the porous sediment boiling module including: Divide the mesh nodes sequentially from the dirt surface to the wall; Set the dirt interior to a capillary porous structure and set the parameter boundary value of the dirt surface; The energy equation and heat transfer equation of the dirt are constructed, and the parameter boundary values ​​of the dirt surface are input into the energy equation and the heat transfer equation to calculate the mass evaporation rate of each grid node.

3. The mass evaporation rate calculation method according to claim 2, characterized in that: The parameter boundary values ​​of the fouling surface include the temperature of the fouling surface and the mass evaporation rate gradient of the fouling surface.

4. The mass evaporation rate calculation method according to claim 3, characterized in that: Calculating the mass evaporation rate for each grid node involves: The mass evaporation rate of the dirt surface is calculated based on the heat flux transferred by heat conduction on the dirt surface and the heat flux on the wall; Calculate the temperature gradient of each grid node according to the energy equation, and calculate the temperature of each grid node according to the temperature of the fouling surface and the temperature gradient; Calculate the mass evaporation rate gradient of each grid node according to the heat transfer equation and the temperature of each grid node; The mass evaporation rate of each grid node is calculated according to the mass evaporation rate of the dirt surface, the mass evaporation rate gradient of the dirt surface and the mass evaporation rate gradient of each grid node.

5. The mass evaporation rate calculation method according to claim 3, characterized in that: The mass evaporation rate of the dirt surface is calculated by the following formula: in, is the vapor phase enthalpy of the dirt surface, is the liquid phase enthalpy of the dirt surface, is the heat flow transferred by heat conduction on the dirt surface, is the heat flux on the wall, and G(1) is the mass evaporation rate of the dirt surface.

6. The mass evaporation rate calculation method according to claim 4, characterized in that: The energy equation is: in, is the heat flux transferred by heat conduction at the n+1th grid node, is the thermal conductivity of the dirt, is the temperature gradient of the n+1th grid node.

7. The mass evaporation rate calculation method according to claim 4, characterized in that: The heat transfer equation is: in, is the volume heat transfer coefficient of phase change, is the saturation temperature of the liquid inside the dirt, is the temperature of the grid node, is the latent heat of vaporization, is the mass evaporation rate gradient.

8. The mass evaporation rate calculation method according to claim 1, characterized in that: Calculating the mass evaporation rate of the node based on the boiling heat flux and mass evaporation module includes: The calculation only considers the wall temperature of forced convection heat transfer and the wall temperature at the boiling start point; Determine whether the wall temperature considering only forced convection heat transfer is greater than the wall temperature at the boiling starting point, and if so, calculate the heat flux density component by the subcooled boiling equation; The mass evaporation rate is calculated based on the heat flux density component and the latent heat of vaporization.

9. The mass evaporation rate calculation method according to claim 8, characterized in that: The wall temperature considering only forced convection heat transfer is calculated by the following formula: in, is the wall temperature considering only forced convection heat transfer, is the fluid temperature, is the forced convection heat transfer coefficient, and q is the heat flux density.

10. The mass evaporation rate calculation method according to claim 8, characterized in that: The boiling starting point wall temperature is calculated by the following formula: in, is the wall temperature at the boiling starting point, is the fluid temperature, is the heat flux component at the boiling starting point, is the heat transfer coefficient at the boiling onset.

11. The mass evaporation rate calculation method according to claim 8, characterized in that: The subcooled boiling equation is: Where q is the heat flux, is the saturated boiling heat flux component, is the heat flux component at the boiling starting point, is the forced convection heat flux component, and n is the preset weight value.

12. The mass evaporation rate calculation method according to claim 11, characterized in that: The mass evaporation rate is calculated by the following formula: in, is the mass evaporation rate, is the latent heat of vaporization.

13. The mass evaporation rate calculation method according to claim 8, characterized in that: Also includes: If the wall temperature considering only forced convection heat transfer is less than or equal to the wall temperature at the boiling starting point, the mass evaporation rate is zero.

14. A computing device, characterized in that: include: at least one processor; as well as At least one memory having instructions stored thereon, wherein when the instructions are executed individually or collectively by the at least one processor, the computing device executes the method as claimed in any one of claims 1 to 13.

15. A computer readable medium, characterized in that The computer-readable medium stores instructions, which, when executed individually or collectively by at least one processor of a computing device, cause the computing device to perform the method as claimed in any one of claims 1 to 13.

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