Method for determining hot, cold volume ratio of reactor coolant system

Abstract

The application provides a method for determining the volume ratio of hot and cold areas of a reactor coolant system, and relates to the technical field of overall process design of the reactor coolant system, and the method comprises the following steps: defining the cold area overall volume, the hot area overall volume, the cold section temperature, the hot section temperature and the reactor power of a preset loop of the reactor coolant system; determining the total mass of the hot and cold areas according to the cold area overall volume, the hot area overall volume and the corresponding water density; controlling the total mass to be constant in the process of changing the reactor power, and combining the change trend curve of the water density with the temperature to determine the relationship between the volume ratio of the hot and cold areas and the cold section temperature, the hot section temperature and the reactor power; determining the volume ratio of the hot and cold areas according to the relationship, and generating the arrangement strategy of the reactor coolant system. In this way, by maintaining the total mass of the reactor coolant system to be constant in the regulation range of the power, the volume demand of the pressurizer can be reduced, and the stability of the system operation is enhanced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of overall process design of reactor coolant system, and particularly relates to a method for determining the volume ratio of hot region to cold region of a reactor coolant system. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art known to those skilled in the art.

[0003] When a nuclear power plant participates in grid peak shaving for load regulation, different parts of the primary loop will simultaneously contract and expand, and the volume of the primary loop itself cannot completely accommodate the volume change, so the volume change needs to be accommodated by the volume of the pressurizer, and if the capacity of the pressurizer is not enough, the volume control needs to be performed by the charging and discharging of the containment system.

[0004] Generally, the reactor pressure vessel, the main pipe and the steam generator have no special relevance in volume design, but if the volume ratio of the cold region to the hot region of the controllable system is controlled, when the reactor power changes, the expansion amount of the hot region can just compensate for the contraction amount of the cooling, so that the capacity requirement of the pressurizer can be reduced, and during normal load regulation, the liquid level and pressure of the pressurizer hardly change or change, which has good operation stability. Therefore, how to determine the volume ratio of the hot region to the cold region of the reactor coolant system is a problem to be solved at present. SUMMARY

[0005] In order to solve the above problems, the present application provides a method for determining the volume ratio of the hot region to the cold region of a reactor coolant system, under the action of a reactor average temperature control system during power regulation, the volume ratio of the selected system hot region to cold region is designed to maintain the total mass of the reactor coolant system constant within the power regulation range, so as to reduce the volume requirement of the pressurizer and enhance the stability of system operation.

[0006] In order to achieve the above purpose, the present application mainly includes the following aspects:

[0007] In a first aspect, the present application provides a method for determining the volume ratio of the hot region to the cold region of a reactor coolant system, comprising:

[0008] defining the total volume of the cold region, the total volume of the hot region, the cold section temperature, the hot section temperature and the reactor power of a preset loop of the reactor coolant system;

[0009] determining total mass of hot and cold regions according to the total volume of the cold region, the total volume of the hot region and the corresponding water density; controlling the total mass to be constant during the change of the reactor power, and determining the relationship between the volume ratio of the hot and cold regions and the cold section temperature, the hot section temperature and the reactor power in combination with the trend curve of the water density with temperature;

[0010] determining the volume ratio of the hot and cold regions according to the relationship, and generating the arrangement strategy of the reactor coolant system.

[0011] In a possible implementation, the total mass of the hot and cold regions is the sum of the mass of the hot region and the mass of the cold region, the mass of the hot region is the product of the total volume of the hot region and the water density, and / or the mass of the cold region is the product of the total volume of the cold region and the water density.

[0012] In a possible implementation, the total mass is controlled to be constant during the change of the reactor power, and the following relationship is obtained:

[0013] ;

[0014] After transformation, the following is obtained:

[0015] ;

[0016] wherein, , k is the volume ratio of the hot and cold regions, V cold is the total volume of the cold region, V hot is the total volume of the hot region, p cold is the density of the cold fluid, p hot is the density of the hot fluid, and C is a constant.

[0017] In a possible implementation, under the premise that the pressure of the reactor coolant system is maintained constant during normal operation, the water density is obtained according to the water property table according to the known temperature, the trend curve of the water density with temperature is fitted, the derivative of the temperature is obtained, and the following is obtained:

[0018] ;

[0019] wherein, a , b is a constant, T is the temperature, p is the water density.

[0020] In a possible implementation, the derivative of the reactor power P is obtained on both ends of the relationship, and multiplied by at the same time, and the following is obtained:

[0021] ;

[0022] And transform it to get:

[0023] ;

[0024] Thus, the relationship between the volume ratio of the hot region and the cold region and the temperature of the cold section, the temperature of the hot section and the reactor power is determined.

[0025] In a possible implementation, when a pressurized water reactor nuclear power plant is designed, the volume ratio of the hot region and the cold region is controlled at a value k, so that the reactor coolant system is stably operated.

[0026] In a possible implementation, the arrangement strategy includes adjusting the length of the equipment design or the pipe in the reactor coolant system.

[0027] In a second aspect, an embodiment of the present application provides a system for determining the volume ratio of the hot region and the cold region of a reactor coolant system, comprising:

[0028] A definition module is configured to define the total volume of the cold region, the total volume of the hot region, the temperature of the cold section, the temperature of the hot section and the reactor power of a preset loop of the reactor coolant system.

[0029] A determination module is configured to determine the total mass of the hot region and the cold region according to the total volume of the cold region, the total volume of the hot region and the corresponding water density, control the total mass to be constant during the change of the reactor power, and determine the relationship between the volume ratio of the hot region and the cold region and the temperature of the cold section, the temperature of the hot section and the reactor power in combination with the trend curve of the change of the water density with the temperature.

[0030] A generation module is configured to determine the volume ratio of the hot region and the cold region according to the relationship and generate an arrangement strategy of the reactor coolant system.

[0031] In a third aspect, an embodiment of the present application provides a computer device, comprising a processor, a memory and a bus, the memory stores machine readable instructions executable by the processor, when the computer device is running, the processor and the memory communicate through the bus, and the machine readable instructions are executed by the processor to perform the steps of the method for determining the volume ratio of the hot region and the cold region of the reactor coolant system as described in the first aspect and any possible implementation of the first aspect.

[0032] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by the processor to perform the steps of the method for determining the volume ratio of the hot region and the cold region of the reactor coolant system as described in the first aspect and any possible implementation of the first aspect.

[0033] The above one or more technical solutions have the following beneficial effects:

[0034] The method for determining the volume ratio of the hot region to the cold region of the reactor coolant system provided by the application determines the relationship between the volume ratio of the hot region to the cold region, the cold section temperature, the hot section temperature and the reactor power by controlling the total mass constant during the change of the reactor power and combining the water density change trend curve with the temperature, thereby determining the volume ratio of the hot region to the cold region and generating the arrangement strategy of the reactor coolant system. Through the reactor coolant system designed by the method, when the reactor power changes, the expansion amount of the hot region can just compensate the shrinkage amount of the cooling, which can reduce the capacity requirement of the pressurizer, and the liquid level and pressure of the pressurizer will hardly change during the normal load adjustment, thereby having good operation stability. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application. The embodiments of these drawings illustrate one or more aspects of the application and, together with their description, serve to explain the application.

[0036] Figure 1 is a flowchart of the method for determining the volume ratio of the hot region to the cold region of the reactor coolant system provided by the first embodiment of the application;

[0037] Figure 2 is a structural schematic diagram of the reactor coolant system provided by the first embodiment of the application;

[0038] Figure 3 is a water density change trend curve diagram provided by the first embodiment of the application;

[0039] Figure 4 is a typical temperature change graph with power provided by the first embodiment of the application. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with the drawings and embodiments.

[0041] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs.

[0042] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0043] Embodiment one

[0044] When a nuclear power plant participates in grid peak shaving for load adjustment, the hot region and the cold region of the primary loop will simultaneously shrink and expand. If the volume of the loop itself cannot completely accommodate this volume change, the volume of the surge tank needs to be used to accommodate this volume change. If the surge tank capacity is insufficient, the charging and discharging of the volume control system also needs to be used for volume control. Figure 1 As shown in the figure, taking a typical dispersed two-loop reactor coolant system as an example, the reactor coolant system includes a reactor core, a main pump, a surge tank and a steam generator, the total volume of the cold region Vcold = (V1+V2) loop1 +(V1+V2) loop2 +V3+V4+ V5, the total volume of the hot region Vhot = V6 + V7 loop1 + V7 loop2 .

[0045] When load adjustment is performed, the hot region and the cold region will simultaneously shrink and expand. If the expansion amount of the hot region can exactly compensate for the shrinkage amount of the cold region during normal load adjustment, the liquid level and the pressure of the surge tank will hardly change, and the reactor coolant system has good operation stability.

[0046] Based on this, the embodiment of the present application provides a method for determining the volume ratio of the hot region and the cold region of a reactor coolant system, as shown in the figure, the method specifically includes the following steps: Figure 2

[0047] S201: Defining the total volume of the cold region, the total volume of the hot region, the cold section temperature, the hot section temperature and the reactor power of a preset loop of a reactor coolant system.

[0048] In a specific implementation, taking a nuclear power plant reactor primary loop as an example, the total volumes of the cold region (cold pipe section, pressure vessel descending section, lower head, main pump, steam generator outlet chamber) and the hot region (hot pipe section, reactor core outlet to hot pipe section joint nozzle, steam generator inlet chamber) of the reactor primary loop are defined as V cold and V hot , the cold section temperature is denoted as T cold , and the hot section temperature is denoted as T hot ​, the reactor power is P. For other different reactors (integrated, compact small reactor), V cold is the volume of the area through which the cold fluid flows, V hot is the volume of the area through which the hot fluid flows, here, cold and hot are relative to the average temperature.

[0049] S202: According to the total volume of the cold region, the total volume of the hot region and the corresponding water density, the total mass of the hot and cold regions is determined; during the change of the reactor power, the total mass is controlled to be constant, and the relationship between the volume ratio of the hot and cold regions, the cold section temperature, the hot section temperature and the reactor power is determined in combination with the temperature change trend curve of the water density.

[0050] In specific implementation, during the power increase process, in order to achieve the purpose that the volume expansion amount of the hot section can exactly compensate the volume shrinkage amount of the cold section, the total mass of this part should also be controlled to be approximately constant. Optionally, the total mass of the hot and cold regions is the sum of the mass of the hot region and the mass of the cold region, the mass of the hot region is the product of the total volume of the hot region and the water density; and / or, the mass of the cold region is the product of the total volume of the cold region and the water density.

[0051] During the change of the reactor power (P1~P2, P1

[0052] ;

[0053] After transformation, we get:

[0054] ;

[0055] wherein, , k is the volume ratio of the hot and cold regions, p cold is the density of the cold fluid, p hot is the density of the hot fluid, and C is a constant.

[0056] Since the normal operating pressure of the reactor coolant system is maintained unchanged, under the premise of considering the unchanged pressure, the density of water can be obtained according to the water property table according to the known temperature, the change trend curve of the water density with temperature is fitted, as shown in Figure 3 , and the derivative of the temperature is obtained:

[0057] ;

[0058] wherein, a , b is a constant, T is the temperature, p is the water density, Figure 3 in the interval shown,a = -0.0232, b = 4.9.

[0059] Deriving the two ends of the relationship respectively to the reactor power P, and multiplying by , we get:

[0060] ;

[0061] And transforming it to get:

[0062] ;

[0063] Thus the relationship between the hot and cold region volume ratio and the cold section temperature, the hot section temperature and the reactor power is determined.

[0064] From the perspective of engineering implementation, P1~P2 is the range where power regulation is relatively frequent, and the cold and hot section temperature changes can be approximately considered as linear changes, as shown in Figure 4 Considering certain approximation, we can get:

[0065] .

[0066] S203: determining the hot and cold region volume ratio according to the relationship, and generating a layout strategy of the reactor coolant system.

[0067] In specific implementation, when a pressurized water reactor nuclear power plant is designed, the volume ratio of the hot region to the cold region is controlled at a value k, so that the reactor coolant system can be stably operated. Optionally, the layout strategy includes adjusting the design of equipment in the reactor coolant system or the length of pipes. That is, in the process of designing the system equipment and layout, the volume ratio of the hot region to the cold region can be adjusted by adjusting the design of equipment or the length of pipes, so that the volume ratio of the hot region to the cold region is the same as or as close as possible to the result of the following formula:

[0068]

[0069] In this way, when the reactor power changes, the expansion amount of the hot region can just compensate for the contraction amount of the cooling, which can reduce the capacity requirement of the pressurizer, and the liquid level and pressure of the pressurizer will hardly change during normal load regulation, thus having good operation stability.

[0070] Embodiment Two

[0071] The embodiment of the present application also provides a system for determining the volume ratio of the hot region to the cold region of a reactor coolant system, comprising:

[0072] The definition module is configured to define a cold region total volume, a hot region total volume, a cold section temperature, a hot section temperature and a reactor power of a reactor coolant system preset loop;

[0073] The determination module is configured to determine a hot region total mass and a cold region total mass according to the cold region total volume, the hot region total volume and a corresponding water density, and determine a relationship between a hot region volume ratio and a cold region volume ratio and the cold section temperature, the hot section temperature and the reactor power by controlling the total mass to be constant during a change of the reactor power and combining a change trend curve of the water density with the temperature.

[0074] The generation module is configured to determine the hot region volume ratio and the cold region volume ratio according to the relationship and generate a layout strategy of the reactor coolant system.

[0075] The determination system of the hot region volume ratio and the cold region volume ratio of the reactor coolant system provided by the embodiment is used to implement the determination method of the hot region volume ratio and the cold region volume ratio of the reactor coolant system, and the specific implementation manners of the determination system of the hot region volume ratio and the cold region volume ratio of the reactor coolant system can be found in the embodiment part of the determination method of the hot region volume ratio and the cold region volume ratio of the reactor coolant system in the foregoing, and will not be described here again.

[0076] Embodiment three

[0077] The embodiment of the present application further provides a computer device, which comprises a processor, a memory and a bus.

[0078] The memory stores machine readable instructions executable by the processor, and the processor and the memory communicate through the bus when the computer device is running. Figure 2 The machine readable instructions are executed by the processor to perform the steps of the determination method of the hot region volume ratio and the cold region volume ratio of the reactor coolant system in the method embodiment, and the specific implementation manners can be found in the method embodiment, and will not be described here again.

[0079] Embodiment four

[0080] Based on the same inventive concept, the embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program performs the steps of the determination method of the hot region volume ratio and the cold region volume ratio of the reactor coolant system in the method embodiment when executed by the processor.

[0081] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, the program can include the processes of the above-mentioned embodiment methods. The storage medium can be a magnetic disc, an optical disc, a read-only memory (ROM), a random access memory (RAM), or the like.

[0082] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for determining the volume ratio of hot and cold zones in a reactor coolant system, characterized in that, include: Define the total volume of the cold zone, the total volume of the hot zone, the cold zone temperature, the hot zone temperature, and the reactor power of the preset loop of the reactor coolant system; Based on the total volume of the cold zone, the total volume of the hot zone, and the corresponding water density, the total mass of the hot and cold zones is determined; during the process of reactor power change, the total mass is kept constant, and the relationship between the volume ratio of the hot and cold zones and the cold section temperature, the hot section temperature, and the reactor power is determined by combining the water density change trend curve with temperature. The total mass of the hot and cold regions is the sum of the masses of the hot and cold regions, and the mass of the hot region is the product of the total volume of the hot region and the density of water; and / or, the mass of the cold region is the product of the total volume of the cold region and the density of water. By keeping the total mass constant during reactor power variation, the following relationship is obtained: ; By transforming it, we get: ; in, , k The ratio of hot to cold zone volume. V cold For the total volume of the cold zone, V hot For the total volume of the hot zone, ρ cold For cold fluid density, ρ hot Where C is the density of the thermal fluid and C is a constant; Assuming the pressure remains constant during normal operation of the reactor coolant system, and given the temperature, the water density is obtained from the water property table. By fitting a curve showing the change in water density with temperature and taking the derivative with respect to temperature, we obtain: ;in, a , b It is a constant. T For temperature, ρ The density of water; For the aforementioned relation Differentiate both ends of the equation with respect to the reactor power P, and multiply by the derivative. ,get: ; And by transforming it, we get: ; This establishes the relationship between the volume ratio of the hot and cold zones and the temperatures of the cold and hot zones, as well as the reactor power. Based on the aforementioned relationship, the volume ratio of the hot and cold zones is determined, and a layout strategy for the reactor coolant system is generated.

2. The method for determining the volume ratio of the hot and cold zones in a reactor coolant system as described in claim 1, characterized in that, When designing a pressurized water reactor nuclear power plant, the volume ratio of the hot zone to the cold zone is controlled at a value of k to ensure the stable operation of the reactor coolant system.

3. The method for determining the volume ratio of the hot and cold zones in a reactor coolant system as described in claim 1, characterized in that, The layout strategy includes adjusting the design of equipment or the length of piping in the reactor coolant system.

4. A system for determining the volume ratio of hot and cold zones in a reactor coolant system, characterized in that, include: The definition module is used to define the total volume of the cold zone, the total volume of the hot zone, the cold zone temperature, the hot zone temperature, and the reactor power of the preset loop of the reactor coolant system; The determination module is used to determine the total mass of the hot and cold regions based on the total volume of the cold region, the total volume of the hot region, and the corresponding water density; during the reactor power change process, the total mass is kept constant, and the relationship between the volume ratio of the hot and cold regions and the cold section temperature, the hot section temperature, and the reactor power is determined by combining the water density change trend curve with temperature; the total mass of the hot and cold regions is the sum of the mass of the hot region and the mass of the cold region, the mass of the hot region is the product of the total volume of the hot region and the water density; and / or, the mass of the cold region is the product of the total volume of the cold region and the water density; By keeping the total mass constant during reactor power variation, the following relationship is obtained: ; By transforming it, we get: ; in, , k The ratio of hot to cold zone volume. V cold For the total volume of the cold zone, V hot For the total volume of the hot zone, ρ cold For cold fluid density, ρ hot Where C is the density of the thermal fluid and C is a constant; Assuming the pressure remains constant during normal operation of the reactor coolant system, and given the temperature, the water density is obtained from the water property table. By fitting a curve showing the change in water density with temperature and taking the derivative with respect to temperature, we obtain: ;in, a , b It is a constant. T For temperature, ρ The density of water; For the aforementioned relation Differentiate both ends of the equation with respect to the reactor power P, and multiply by the derivative. ,get: ; And by transforming it, we get: ; This establishes the relationship between the volume ratio of the hot and cold zones and the temperatures of the cold and hot zones, as well as the reactor power. The generation module is used to determine the volume ratio of hot and cold zones based on the relationship and to generate a layout strategy for the reactor coolant system.

5. A computer device, characterized in that, include: The system includes a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the computer device is running, the processor communicates with the memory via the bus. When the machine-readable instructions are executed by the processor, they perform the steps of the method for determining the hot and cold zone volume ratio of a reactor coolant system as described in any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the method for determining the hot and cold zone volume ratio of a reactor coolant system as described in any one of claims 1 to 3.

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