An experimental system and method for transient characteristics of key physical phenomena in a continuous analog core makeup water tank

Abstract

The present invention discloses an experimental system and method for continuously simulating the transient characteristics of key physical phenomena of a continuous makeup tank (CMT), including a pressurizer and a CMT simulator; the bottom of the pressurizer is connected to the top of the CMT simulator through a connecting pipeline; an electric heating element is installed in the pressurizer; a balance valve is installed on the connecting pipeline; the bottom of the CMT simulator is connected with a drainage pipeline, and an orifice plate and a quick-opening valve are installed on the drainage pipeline. The experimental system of the present invention can continuously and sequentially simulate the transient characteristics of the key physical phenomena of the CMT, namely, the mixing of hot and cold water under high temperature and high pressure, the direct contact condensation of high temperature and high pressure saturated steam-water, and the steam wall condensation phenomenon. At the same time, it has the function of studying the influence of different initial pressures, initial water temperatures, and initial drainage volumes on the key physical phenomena of the CMT, and has the characteristics of flexibility, convenience, economy, high efficiency, and complete functions.

Description

Technical Field

[0001] The present invention relates to the technical field of experimental research equipment related to nuclear reactor safety. Specifically, it relates to an experimental system and method for continuously simulating the transient characteristics of key physical phenomena in a core makeup tank. Background Art

[0002] With the rapid development of nuclear power technology, the passive safety injection system, as a new design concept, has been widely applied in civil nuclear power plants to cope with loss-of-coolant accidents. The core makeup tank (CMT) is a key device of the passive safety injection system. Its top pressure balance pipeline is connected to the cold leg, and the outlet pipeline is connected to the direct injection pipeline of the reactor pressure vessel. It plays an important safety guarantee role when a loss-of-coolant accident occurs in the reactor. When the cold leg is full of water, the CMT conducts safety injection in a water-water circulation mode. Hot water enters from the top of the CMT, and cold water flows out from the bottom of the CMT. High-temperature and high-pressure hot water and cold water are mixed inside the CMT. When the water inventory in the primary loop system decreases and the cold leg is emptied, steam enters the CMT through the pressure balance pipeline, then it is in a steam-water circulation mode. At this time, high-temperature and high-pressure saturated steam contacts and condenses with the wall and water inside the CMT. Whether it is the cold and hot water mixing phenomenon in the water-water circulation mode or the steam condensation phenomenon in the steam-water circulation mode, both have an important impact on the safety injection characteristics of the CMT.

[0003] Therefore, it is very important to study the influence law of the key physical phenomena inside the CMT on its safety injection characteristics. At present, the existing methods need to simulate the reactor pressure vessel and the passive safety injection system to study the key physical phenomena inside the CMT and its safety injection characteristics, which are costly and complex to operate.

[0004] In view of this, the present application is specifically proposed. Summary of the Invention

[0005] The problem of the existing technology is that currently, it is necessary to simulate the reactor pressure vessel and the passive safety injection system to study the key physical phenomena inside the CMT and its safety injection characteristics, which are costly and complex to operate. The purpose of the present invention is to provide an experimental system and method for continuously simulating the transient characteristics of key physical phenomena in a core makeup tank, which can continuously and sequentially simulate the transient characteristics of key physical phenomena in the CMT, such as high-temperature and high-pressure cold and hot water mixing, high-temperature and high-pressure saturated steam-water direct contact condensation, and steam wall condensation phenomena. At the same time, it has the function of studying the influence of different initial pressures, initial water temperatures, and initial drainage volumes on the key physical phenomena in the CMT, and has the characteristics of flexibility, convenience, economy, high efficiency, and complete functions.

[0006] The present invention is realized through the following technical solutions:

[0007] The present invention provides an experimental system for continuously simulating the transient characteristics of key physical phenomena in a core makeup tank, including a pressurizer and a core makeup tank simulator; the bottom of the pressurizer is connected to the top of the core makeup tank simulator through a connecting pipeline; an electric heating element is installed inside the pressurizer; a balance valve is installed on the connecting pipeline; a drain pipeline is connected to the bottom of the core makeup tank simulator.

[0008] In the experimental system of the present invention, first, the pressurizer is equipped with an electric heating element. Before the start of the transient experiment, a pressurizer space with hot water at the bottom and steam at the top can be established. Second, the structure of connecting the bottom of the pressurizer to the top of the core makeup tank simulator is adopted. In this way, at the start of the transient experiment, the heated hot water and the generated water vapor in the pressurizer can enter the top of the core makeup tank simulator in sequence from the bottom of the pressurizer. The hot water at the bottom of the pressurizer first enters the simulator to cause cold-hot water mixing, and then the steam in the pressurizer enters the simulator to cause steam condensation. It can continuously and sequentially simulate the cold-hot water mixing, steam-water direct contact condensation, and steam-wall condensation phenomena inside the CMT, so as to realize the research on the safety injection characteristics of the water-water circulation mode and the steam-water circulation mode inside the CMT.

[0009] Furthermore, a throttle orifice plate is detachably installed on the drain pipeline. By installing and replacing throttle orifice plates of different models, the adjustment and control of different initial drainage flows can be realized, and experiments with different initial drainage flows can be carried out, so as to study the influence of different initial drainage flows on the key physical phenomena of the CMT.

[0010] Furthermore, a quick-opening valve is also installed on the drain pipeline, which can conveniently control the discharge of the liquid at the bottom of the core makeup tank simulator.

[0011] Furthermore, a pressure measuring device, a temperature measuring device, and a liquid level measuring device are installed on the core makeup tank simulator, which can capture the characteristic parameters of the key physical phenomena inside the core makeup tank simulator.

[0012] Furthermore, an electric heating element is also installed on the core makeup tank simulator, which can adjust and control the initial water temperature inside the core makeup tank simulator through the electric heating element. Experiments with different initial water temperatures can be carried out, so as to study the influence of different initial water temperatures on the key physical phenomena of the CMT.

[0013] Furthermore, the pressurizer has a cylindrical barrel structure.

[0014] Furthermore, both the pressurizer and the core makeup tank simulator are connected to an external water replenishment system. Water is injected into the pressurizer and the core makeup tank simulator through the external water replenishment system to control the initial pressure inside both of them. Experiments with different initial pressures can be carried out, so as to study the influence of different initial pressures on the key physical phenomena of the CMT.

[0015] The present invention also provides an experimental method for continuously simulating the transient characteristics of key physical phenomena of a core makeup tank, comprising the following steps:

[0016] 1) Install an orifice plate with a specific size on the drain pipeline to simulate a specific initial drainage flow rate;

[0017] 2) Use an external water replenishing system to add water to the pressurizer and the core makeup tank simulator, raise the pressure to the target pressure, and open the pressure balance valve on the connecting pipeline to balance the pressure between the pressurizer and the core makeup tank simulator;

[0018] 3) Turn on the electric heating element of the pressurizer to heat the water in the pressurizer and establish a steam space in the pressurizer;

[0019] 4) Turn on the electric heating element of the core makeup tank simulator and heat the water temperature in the simulator to the target water temperature;

[0020] 5) Open the quick-opening valve on the drain pipeline, the pressure of the experimental system decreases, the hot water at the bottom of the pressurizer enters the core makeup tank simulator under the action of the pressure difference, a cold and hot water mixing process occurs, and the cold water at the bottom of the core makeup tank simulator gradually drains out from the drain pipeline to ensure that the medium in the core makeup tank simulator is always at a full liquid level;

[0021] 6) When the liquid in the pressurizer is emptied, the steam enters the core makeup tank simulator through the connecting pipeline, steam-water contact condensation occurs, the liquid level of the core makeup tank simulator gradually decreases, steam continuously enters the core makeup tank simulator, and steam wall condensation phenomenon occurs until the liquid in the core makeup tank simulator is emptied and the experiment ends.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] 1. For the experimental system and method for continuously simulating the transient characteristics of key physical phenomena of a core makeup tank provided in the embodiment of the present invention, the pressurizer is equipped with an electric heating element. Before the transient experiment starts, a pressurizer space with hot water at the bottom and steam at the top can be established. Secondly, a structure in which the bottom of the pressurizer is connected to the top of the core makeup tank simulator is adopted. In this way, at the beginning of the transient experiment, the heated hot water and the generated water vapor in the pressurizer can sequentially enter the top of the core makeup tank simulator from the bottom of the pressurizer, and the transient characteristics of the high-temperature and high-pressure cold and hot water mixing, high-temperature and high-pressure saturated steam-water direct contact condensation, and steam wall condensation phenomena, which are the key physical phenomena of the CMT, can be continuously simulated in sequence;

[0024] 2. An experimental system and method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to an embodiment of the present invention. A throttle orifice plate is detachably installed on the drain pipeline. By installing and replacing throttle orifice plates of different models, the regulation and control of different initial drainage flows can be achieved, and experiments with different initial drainage flows can be carried out, so as to study the influence of different initial drainage flows on the key physical phenomena of the CMT.

[0025] 3. An experimental system and method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to an embodiment of the present invention. An electric heating element is also installed in the core makeup water tank simulator, and the initial water temperature in the core makeup water tank simulator can be adjusted and controlled through the electric heating element. Experiments with different initial water temperatures can be carried out, so as to study the influence of different initial water temperatures on the key physical phenomena of the CMT.

[0026] 4. An experimental system and method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to an embodiment of the present invention. Water is injected into the pressurizer and the core makeup water tank simulator through an external makeup water system to control the initial pressure inside both of them. Experiments with different initial pressures can be carried out, so as to study the influence of different initial pressures on the key physical phenomena of the CMT.

[0027] 5. An experimental system and method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to an embodiment of the present invention. It has the function of studying the influence of different initial pressures, initial water temperatures, and initial drainage volumes on the key physical phenomena of the CMT, and has the characteristics of flexibility, convenience, economy, high efficiency, and complete functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a schematic structural diagram of the experimental system provided by an embodiment of the present invention.

[0030] Reference numerals and corresponding component names:

[0031] 1 - Pressurizer, 2 - Connecting pipeline, 3 - Balance valve, 4 - CMT simulator, 5 - Drain pipeline, 6 - Throttle orifice plate, 7 - Quick - opening valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those of ordinary skill in the art that: the present invention may be practiced without these specific details. In other instances, well-known structures, materials, or methods have not been specifically described in order to avoid obscuring the present invention.

[0034] Throughout the specification, references to "one embodiment", "an embodiment", "one example" or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, the phrases "one embodiment", "an embodiment", "one example" or "an example" appearing throughout the specification do not necessarily all refer to the same embodiment or example. Additionally, the specific features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art should understand that the diagrams provided herein are for illustrative purposes only and are not necessarily drawn to scale. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0035] In the description of the present invention, the orientation or positional relationships indicated by the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention.

[0036] Embodiment 1

[0037] As Figure 1 shown, the embodiment of the present invention provides an experimental system for continuously simulating the transient characteristics of key physical phenomena of a core makeup tank, including a pressurizer 1 and a core makeup tank simulator 4; the bottom of the pressurizer is connected to the top of the core makeup tank simulator through a connecting pipeline 2; an electric heating element is installed in the pressurizer; a balance valve 3 is installed on the connecting pipeline; and a drainage pipeline 5 is connected to the bottom of the core makeup tank simulator.

[0038] The experimental system of the present invention is as follows: First, the pressure regulator is equipped with an electric heating element. Before the transient experiment starts, it can establish a pressure regulator space with hot water at the bottom and steam at the top. Second, a structure is adopted where the bottom of the pressure regulator is connected to the top of the simulated core makeup tank. In this way, when the transient experiment starts, the heated hot water and the generated water vapor in the pressure regulator can sequentially enter the top of the simulated core makeup tank from the bottom of the pressure regulator. The hot water at the bottom of the pressure regulator first enters the simulator and mixes with cold water, and then the steam in the pressure regulator enters the simulator and condenses. It can continuously and sequentially simulate the phenomena of cold and hot water mixing, steam-water direct contact condensation, and steam-wall condensation inside the CMT, so as to realize the research on the safety injection characteristics of the water-water circulation mode and the steam-water circulation mode inside the CMT.

[0039] Preferably, a throttle orifice plate 6 is detachably installed on the drain pipeline. By installing and replacing throttle orifice plates of different models, the adjustment and control of different initial drainage flows can be realized, and experiments with different initial drainage flows can be carried out, so as to study the influence of different initial drainage flows on the key physical phenomena of the CMT.

[0040] Preferably, a quick-opening valve 7 is also installed on the drain pipeline, which can conveniently control the discharge of the liquid at the bottom of the simulated core makeup tank.

[0041] Preferably, the simulated core makeup tank is equipped with a pressure measuring device, a temperature measuring device, and a liquid level measuring device, which can capture the characteristic parameters of the key physical phenomena inside the simulated core makeup tank.

[0042] Preferably, the simulated core makeup tank is also equipped with an electric heating element, which can adjust and control the initial water temperature inside the simulated core makeup tank through the electric heating element. Experiments with different initial water temperatures can be carried out, so as to study the influence of different initial water temperatures on the key physical phenomena of the CMT.

[0043] Preferably, the pressure regulator has a cylindrical barrel structure.

[0044] Preferably, both the pressure regulator and the simulated core makeup tank are connected to an external water supply system. Water is injected into the pressure regulator and the simulated core makeup tank through the external water supply system to control the initial pressure inside both of them. Experiments with different initial pressures can be carried out, so as to study the influence of different initial pressures on the key physical phenomena of the CMT.

[0045] Example 2

[0046] The embodiment of the present invention provides an experimental method for continuously simulating the transient characteristics of the key physical phenomena of the core makeup tank, including the following steps:

[0047] 1) Install a throttle orifice plate with a specific size on the drain pipeline to simulate a specific initial drainage flow;

[0048] 2) Use an external water supply system to add water to the pressurizer and the simulated accumulator to raise the pressure to the target pressure. Open the pressure balance valve on the connecting pipeline to balance the pressure between the pressurizer and the simulated accumulator;

[0049] 3) Turn on the electric heating element of the pressurizer to heat the water in the pressurizer and establish a steam space in the pressurizer;

[0050] 4) Turn on the electric heating element of the simulated accumulator and heat the water temperature in the simulator to the target water temperature;

[0051] 5) Open the quick-opening valve on the drain pipeline. The pressure of the experimental system decreases. The hot water at the bottom of the pressurizer enters the simulated accumulator under the action of the pressure difference, and a cold-hot water mixing process occurs. The cold water at the bottom of the simulated accumulator gradually drains out from the drain pipeline to ensure that the medium in the simulated accumulator is always at the full liquid level;

[0052] 6) When the liquid in the pressurizer is emptied, the steam enters the simulated accumulator through the connecting pipeline, and steam-water contact condensation occurs. The liquid level of the simulated accumulator gradually decreases, and the steam continuously enters the simulated accumulator, and steam-wall condensation occurs until the liquid in the simulated accumulator is emptied and the experiment ends.

[0053] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank, characterized in that, It is carried out using an experimental system, and the experimental system includes a pressurizer (1) and a simulated core makeup water tank (4); The bottom of the pressurizer (1) is connected to the top of the simulated core makeup water tank (4) through a connecting pipeline (2); An electric heating element is installed in the pressurizer (1); a balance valve (3) is installed on the connecting pipeline (2); A drain pipeline (5) is connected to the bottom of the simulated core makeup water tank (4); It includes the following steps: 1) Install an orifice plate with a specific size on the drain pipeline to simulate a specific initial drainage flow rate; 2) Use an external makeup water system to add water to the pressurizer and the simulated core makeup water tank to raise the pressure to the target pressure, and open the pressure balance valve on the connecting pipeline to balance the pressure between the pressurizer and the simulated core makeup water tank; 3) Turn on the electric heating element of the pressurizer to heat the water in the pressurizer and establish a steam space in the pressurizer; 4) Turn on the electric heating element of the simulated core makeup water tank to heat the water temperature in the simulated tank to the target water temperature; 5) Open the quick-opening valve on the drain pipeline, the pressure of the experimental system decreases, the hot water at the bottom of the pressurizer enters the simulated core makeup water tank under the action of the pressure difference, and a cold and hot water mixing process occurs. The cold water at the bottom of the simulated core makeup water tank gradually drains out from the drain pipeline to ensure that the medium in the simulated core makeup water tank is always at a full liquid level; 6) When the liquid in the pressurizer is emptied, the steam enters the simulated core makeup water tank through the connecting pipeline, and steam-water contact condensation occurs. The liquid level of the simulated core makeup water tank gradually decreases, and the steam continuously enters the simulated core makeup water tank, and steam-wall condensation occurs until the liquid in the simulated core makeup water tank is emptied, and the experiment ends.

2. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 1, characterized in that, An orifice plate (6) is detachably installed on the drain pipeline (5).

3. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 1, characterized in that, A quick-opening valve (7) is also installed on the drain pipeline (5).

4. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 1, characterized in that, The simulated core makeup water tank (4) is equipped with a pressure measuring device.

5. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 1, characterized in that, The simulated core makeup water tank (4) is equipped with a temperature measuring device.

6. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 1, characterized in that, The simulated core makeup water tank (4) is also equipped with a liquid level measuring device.

7. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 1, characterized in that, The simulated core makeup water tank (4) is also equipped with an electric heating element.

8. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 7, characterized in that, The pressurizer (1) has a cylindrical barrel structure.

9. The experimental method for continuously simulating the transient characteristics of key physical phenomena in a core makeup water tank according to claim 5, characterized in that, Both the pressurizer (1) and the simulated core makeup water tank (4) are connected to an external makeup water system.

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