Water replenishing system of reactor pressure vessel

Abstract

The utility model relates to a water replenishing system of a reactor pressure vessel, which comprises a water storage tank for storing boron water to be replenished, a conveying assembly and a detection unit, the conveying assembly comprises a first conveying unit, a second conveying unit and a third conveying unit, and the detection unit is used for detecting the liquid level and the descending speed of the pressure vessel; when the detection unit detects that the liquid level of the pressure container is higher than a preset liquid level, the first conveying unit conveys boron water to be supplemented to the pressure container; when the liquid level of the pressure container drops at a speed higher than the first preset speed and lower than the second preset speed, the second conveying unit conveys the boron water to be supplemented to the pressure container; when the liquid level of the pressure container drops at a speed higher than a second preset speed, the third conveying unit conveys the to-be-supplemented boron water to the pressure container, and the second preset speed is higher than the first preset speed. The water replenishing system can improve the hysteresis quality of the water replenishing process, realizes quick and timely water replenishing for the pressure vessel, improves the safety of a nuclear reactor, and reduces the risk that maintainers are accidentally irradiated.

Description

Technical Field

[0001] The present application relates to the field of nuclear power safety technology, and in particular to a water replenishment system for a reactor pressure vessel. Background Art

[0002] Nuclear power plants use the energy generated by nuclear reactors to heat the primary coolant (the reactor coolant system in a nuclear power plant system is also called the primary system, or simply the primary loop). The primary coolant then heats the secondary water in the steam generator to generate steam, which then impulses the steam turbine generator set to generate electricity.

[0003] During maintenance of nuclear power plants, the pressure vessels in the primary circuit system need to be opened for inspection, and the liquid level on the flange surface of the pressure vessel needs to be within the normal range when the cover is opened. During inspection, due to the constant change of the liquid level, an abnormal drop in the liquid level of the pressure vessel will cause the reactor core to be exposed, and the nuclear fuel will be directly exposed to the air, which may cause serious problems such as overheating and fuel melting, and increase the risk of accidental exposure of maintenance personnel.

[0004] In the related art, when the liquid level in a circuit drops abnormally, the chemical and volume control system will automatically start the delivery pump to replenish water for the circuit. However, when the liquid level drops, there is a lag in replenishing water through the chemical and volume control system. If the replenishment time is late, the maintenance personnel are still at risk of accidental exposure. Summary of the invention

[0005] Based on this, it is necessary to provide a water replenishment system for a reactor pressure vessel in response to the above technical problems, so as to replenish water to the pressure vessel in time, improve the safety during nuclear reactor maintenance, and reduce the risk of accidental exposure to maintenance personnel.

[0006] The present application provides a water replenishment system for a reactor pressure vessel, the water replenishment system comprising: a water storage tank, the water storage tank is used to store boron water to be replenished; a conveying component, used to convey the boron water to be replenished to the pressure vessel, the conveying component comprising a first conveying unit, a second conveying unit and a third conveying unit, the first conveying unit, the second conveying unit and the third conveying unit are all connected to the water storage tank at one end and connected to the pressure vessel at the other end, the boron water conveying flow rate of the third conveying unit is greater than the boron water conveying flow rate of the second conveying unit, and the boron water conveying flow rate of the second conveying unit is greater than the boron water conveying flow rate of the first conveying unit; and a detection unit, the detection unit is used to detect the liquid level of the pressure vessel and the speed of the liquid level decrease, when the detection unit detects that the liquid level of the pressure vessel is higher than a preset liquid level, the first conveying unit conveys the boron water to be replenished to the pressure vessel; when the detection unit detects that the liquid level of the pressure vessel decreases at a speed higher than the first preset speed and lower than the second preset speed, the second conveying unit conveys the boron water to be replenished to the pressure vessel; when the detection unit detects that the liquid level of the pressure vessel decreases at a speed higher than the second preset speed, the third conveying unit conveys the boron water to be replenished to the pressure vessel, and the second preset speed is greater than the first preset speed.

[0007] In one embodiment, when the liquid level in the pressure vessel decreases at a rate higher than the first preset speed and lower than the second preset speed, the amount of liquid lost in the pressure vessel is less than the amount of boron water delivered by the second delivery unit; and when the liquid level in the pressure vessel decreases at a rate higher than the second preset speed, the amount of liquid lost in the pressure vessel is greater than the amount of boron water delivered by the second delivery unit.

[0008] In one embodiment, the first delivery unit includes a first delivery pump, a first valve and a first delivery pipeline. The first delivery pump is connected to the water tank through the first delivery pipeline, and is used to drive the boron water to be replenished into the pressure vessel along the first delivery pipeline. The first valve is connected between the first delivery pump and the pressure vessel through the first delivery pipeline, and the first valve can adjust the flow rate of the boron water to be replenished input into the pressure vessel through the first delivery pump.

[0009] In one embodiment, the second delivery unit includes a second delivery pump, a second valve and a second delivery pipeline. The second delivery pump is connected to the water tank through the second delivery pipeline and is used to drive the boron water to be replenished into the pressure vessel along the second delivery pipeline. The second valve is connected between the second delivery pump and the pressure vessel through the second delivery pipeline, and the second valve is used to control the conduction or blocking between the second delivery pump and the pressure vessel.

[0010] In one embodiment, the flow rate of the second valve is greater than the flow rate of the first valve; and / or the flow rate of the second delivery pump is greater than the flow rate of the first delivery pump.

[0011] In one embodiment, the length of the second delivery line is shorter than the length of the first delivery line.

[0012] In one embodiment, the third delivery unit includes a third delivery pump and a third delivery pipeline. The third delivery pump is connected between the water storage tank and the pressure vessel through the third delivery pipeline, and is used to drive the boron water to be replenished into the pressure vessel along the third delivery pipeline. The flow rate of the third delivery pump is greater than the flow rate of the second delivery pump.

[0013] In one embodiment, a plurality of third delivery pumps are provided, each of which is connected between the water storage tank and the pressure vessel through a third delivery pipeline, and the plurality of third delivery pumps can drive the boron water to be replenished to be input into the pressure vessel individually or simultaneously.

[0014] In one embodiment, the third delivery pump is a charging pump or a low-pressure injection pump.

[0015] In one embodiment, the first delivery unit and the second delivery unit do not deliver the boron-supplemented water to the pressure container at the same time.

[0016] The water replenishment system of the above-mentioned reactor pressure vessel replenishes water to the pressure vessel in advance before the liquid level of the pressure vessel drops to a preset liquid level through the first conveying unit, replenishes water to the pressure vessel when the liquid level of the pressure vessel drops slowly through the second conveying unit, and replenishes water to the pressure vessel when the liquid level of the pressure vessel drops quickly through the third conveying unit. The water replenishment system can improve the hysteresis of the water replenishment system in response to different liquid level conditions of the pressure vessel, realize rapid and timely water replenishment of the pressure vessel, improve the safety during nuclear reactor maintenance, and reduce the risk of accidental exposure of maintenance personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a schematic diagram of a water replenishment system for a reactor pressure vessel in an embodiment of the present application.

[0018] FIG. 2 is a schematic diagram of a conveying assembly in an embodiment of the present application.

[0019] FIG. 3 is a schematic diagram of a first conveying unit in an embodiment of the present application.

[0020] FIG. 4 is a schematic diagram of a second conveying unit in an embodiment of the present application.

[0021] FIG5 is a schematic diagram of a third delivery unit in an embodiment of the present application, wherein the third delivery pump is a charging pump.

[0022] FIG6 is a schematic diagram of a third delivery unit in an embodiment of the present application, wherein the third delivery pump is a low-pressure injection pump. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0024] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0025] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0026] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0027] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0029] Refer to Figure 1, which shows a schematic diagram of a water replenishment system for a reactor pressure vessel in an embodiment of the present application. The water replenishment system 100 provided in an embodiment of the present application is used to inject water into a pressure vessel 200 of a reactor primary loop system so that the liquid level in the pressure vessel 200 is within a normal range to ensure safety during maintenance.

[0030] The water replenishment system 100 includes a water storage tank 10, a conveying assembly 20 and a detection unit 30. The water storage tank 10 is used to store the boron water to be replenished so as to replenish the pressure vessel 200 of the primary loop system. The conveying assembly 20 is used to convey the boron water to be replenished to the pipeline of the primary loop system, and inject it into the pressure vessel 200 through the pipeline of the primary loop, so that the liquid level of the pressure vessel 200 can be maintained or restored to a preset liquid level. The detection unit 30 is used to detect the liquid level of the pressure vessel 200 and the liquid level drop speed.

[0031] It should be noted that the preset liquid level is the liquid level on the flange surface of the pressure vessel 200. The pressure vessel 200 is provided with a flange, and the flange has a certain thickness. Since the liquid level of the pressure vessel 200 is within the flange thickness range, it is called the flange surface liquid level; when the liquid level of the pressure vessel 200 is within the flange thickness range and within the preset range, it means that the flange surface liquid level of the pressure vessel 200 is within the normal range.

[0032] Specifically, in combination with Figure 2, the conveying assembly 20 includes a first conveying unit 21, a second conveying unit 22 and a third conveying unit 23. The first conveying unit 21, the second conveying unit 22 and the third conveying unit 23 are all connected to the water storage tank 10 at one end and to the pressure container 200 at the other end. The boron water conveying flow rate of the third conveying unit 23 is greater than the boron water conveying flow rate of the second conveying unit 22, and the boron water conveying flow rate of the second conveying unit 22 is greater than the boron water conveying flow rate of the first conveying unit 21.

[0033] When the detection unit 30 detects that the liquid level of the pressure vessel 200 is higher than the preset liquid level, the first conveying unit 21 conveys the boron water to be replenished to the pressure vessel 200; when the detection unit 30 detects that the liquid level of the pressure vessel 200 decreases at a speed higher than the first preset speed and lower than the second preset speed, the second conveying unit 22 conveys the boron water to be replenished to the pressure vessel 200; when the detection unit 30 detects that the liquid level of the pressure vessel 200 decreases at a speed higher than the second preset speed, the third conveying unit 23 conveys the boron water to be replenished to the pressure vessel 200, and the second preset speed is greater than the first preset speed.

[0034] It should be noted that the situation in which the liquid level of the pressure vessel 200 is higher than the preset liquid level refers to the situation in which the liquid level in the pressure vessel 200 is slightly higher than the preset liquid level. At this time, water is replenished to the pressure vessel 200 through the first conveying unit 21, which can not only ensure that the liquid level in the pressure vessel 200 is always within the normal range, but also will not affect the maintenance of the pressure vessel 200. In addition, the advance water replenishment by the first delivery pump 211 can provide an early warning for the drop in the liquid level, so that before the liquid level drops to the preset liquid level, the second conveying unit 22 and the third conveying unit 23 can be started accordingly according to the speed of the liquid level drop to replenish the pressure vessel 200 with water, thereby reducing the impact caused by the lag when switching to the second conveying unit 22 or the third conveying unit 23 for water replenishment, and providing timely and effective water replenishment for the pressure vessel 200.

[0035] The pressure vessel 200 is replenished with water in advance by the first conveying unit 21 before the liquid level of the pressure vessel 200 drops to a preset liquid level, the pressure vessel 200 is replenished with water by the second conveying unit 22 when the liquid level of the pressure vessel 200 drops slowly, and the pressure vessel 200 is replenished with water by the third conveying unit 23 when the liquid level of the pressure vessel 200 drops quickly. This can improve the hysteresis of the water replenishing system 100 in response to different liquid level conditions of the pressure vessel 200, achieve rapid and timely water replenishment of the pressure vessel 200, improve the safety during nuclear reactor maintenance, and reduce the risk of accidental exposure of maintenance personnel.

[0036] Furthermore, when the liquid level in the pressure vessel decreases at a rate higher than the first preset speed and lower than the second preset speed, the loss of liquid in the pressure vessel 200 is less than the boron water delivery amount of the second delivery unit 22; and when the liquid level in the pressure vessel decreases at a rate higher than the second preset speed, the loss of liquid in the pressure vessel 200 is greater than the boron water delivery amount of the second delivery unit 22.

[0037] When the amount of liquid loss in the pressure vessel 200 is less than the boron water delivery amount of the second delivery unit 22, the pressure vessel 200 is replenished with water through the second delivery unit 22, so that the liquid level of the pressure vessel 200 is maintained or restored to a preset liquid level; when the amount of liquid loss in the pressure vessel 200 is greater than the boron water delivery amount of the second delivery unit 22, and the water replenishment of the second delivery unit 22 cannot maintain or restore the liquid level of the pressure vessel 200 to the preset liquid level, the pressure vessel 200 is replenished with water through the third delivery unit 23 with a larger boron water delivery flow rate, so that the liquid in the pressure vessel 200 can be maintained or restored to the preset liquid level.

[0038] It can be understood that when the liquid level in the pressure vessel drops at a rate higher than the second preset speed, the boron water delivery of the third delivery unit 23 should be greater than the loss of liquid in the pressure vessel 200, so that the liquid level in the pressure vessel 200 can gradually rise, avoiding exposure of the core and accidental exposure to maintenance personnel, thereby improving the safety of the reactor.

[0039] In some embodiments, referring to FIG. 3 , the first delivery unit 21 includes a first delivery pump 211, a first valve 212 and a first delivery pipeline 213. The first delivery pump 211 is connected to the water storage tank 10 through the first delivery pipeline 213, and is used to drive the boron water to be replenished into the pressure vessel 200 along the first delivery pipeline 213. The first valve 212 is connected between the first delivery pump 211 and the pressure vessel 200 through the first delivery pipeline 213. The first valve 212 can adjust the flow rate of the boron water to be replenished input into the pressure vessel 200 through the first delivery pump 211.

[0040] Preferably, the first delivery pump 211 is a boric acid delivery pump, and the boric acid delivery pump extracts the boric water to be replenished in the water storage tank 10, thereby replenishing the pressure vessel 200. Preferably, the first valve 212 is a regulating valve, and the flow rate output to the pressure vessel 200 is adjusted by the regulating valve to adapt to the replenishment conditions when the liquid level is higher than different ranges of the preset liquid level.

[0041] The water storage tank 10 is preferably a refueling water tank in the cooling and treatment system (PTR system) of the reactor refueling water pool and the spent fuel water pool. The refueling water tank can provide the boron water required for replenishment of the pressure vessel 200 .

[0042] Optionally, the first delivery pipeline 213 uses part of the pipeline of the reactor boron water replenishment system (REA) and part of the pipeline of the chemical and volume control system (RCV) to inject the boron water to be replenished in the refueling water tank into the pipeline of the primary loop system. Specifically, the boron water to be replenished in the refueling water tank is sequentially passed through the boric acid delivery pump and regulating valve of the REA system to the solvent control box and charging pump of the RCV system, and finally enters the pipeline of the primary loop system.

[0043] In some embodiments, referring to FIG. 4 , the second delivery unit 22 includes a second delivery pump 221, a second valve 222 and a second delivery pipeline 223. The second delivery pump 221 is connected to the water storage tank 10 via the second delivery pipeline 223, and is used to drive the boron water to be replenished into the pressure vessel 200 along the second delivery pipeline 223. The second valve 222 is connected between the second delivery pump 221 and the pressure vessel 200 via the second delivery pipeline 223. The second valve 222 is used to control the conduction or blocking between the second delivery pump 221 and the pressure vessel 200.

[0044] Preferably, the flow rate of the second delivery pump 221 is greater than the flow rate of the first delivery pump 211, so that the boron water delivery amount of the second delivery unit 22 is greater than the boron water delivery amount of the first delivery unit 21. Preferably, the second delivery pipeline 223 and the first delivery pipeline 213 use the same delivery pipeline, and only the first delivery pump 211 is replaced by the second delivery pump 221 with a larger flow rate.

[0045] In other embodiments, the flow rate of the second valve 222 is greater than the flow rate of the first valve 212, so that the boron water delivery flow rate of the second delivery unit 22 is greater than the boron water delivery flow rate of the first delivery unit 21. The second valve 222 is a stop valve, and the flow rate of the stop valve is greater than the maximum opening of the first valve 212.

[0046] Furthermore, the length of the second delivery pipeline 223 is shorter than that of the first delivery pipeline 213, shortening the delivery path of the boron water to be replenished, allowing the boron water to be replenished to enter the pressure vessel 200 faster, so that the boron water delivery flow rate of the second delivery unit 22 is greater than the boron water delivery flow rate of the first delivery unit 21.

[0047] Specifically, the second delivery pump 221 also uses the boric acid delivery pump of the REA system, and the second delivery pipeline 223 also uses part of the pipeline of the REA system and part of the pipeline of the RCV system to inject the boric water to be replenished in the material replacement water tank into the pipeline of the primary circuit system. The boric water to be replenished in the material replacement water tank passes through the boric acid delivery pump of the REA system, the stop valve to the charging pump of the RCV system, etc., and finally enters the pipeline of the primary circuit system. The second delivery pipeline 223 does not pass through the solvent control box of the RCV system, so that the length of the second delivery pipeline 223 is less than the length of the first delivery pipeline 213, and at the same time avoids the diversion of the boric water to be replenished when passing through the solvent control box, thereby increasing the boric water delivery flow of the second delivery unit.

[0048] In this embodiment, due to the partial overlap of the first delivery pipeline 213 and the second delivery pipeline 223, the first delivery unit 21 and the second delivery unit 22 do not simultaneously deliver the boron water to be replenished to the pressure vessel 200, so that the first delivery unit 21 and the second unit can be adapted to different liquid level conditions of the pressure vessel 200 detected by the detection unit 30. The switching of the first delivery unit 21 and the second delivery unit 22 is achieved by switching the first valve 212 and the second valve 222, which helps to improve the orderliness and controllability of the water replenishment process, and helps the detection unit 30 to timely and accurately obtain the liquid level changes of the pressure vessel 200, thereby improving the response accuracy of the water replenishment system 100.

[0049] In other embodiments, the first delivery pipeline 213 and the second delivery pipeline 223 do not overlap, so that the first delivery unit 21 and the second delivery unit 22 can replenish water into the pressure vessel 200 at the same time, which helps to improve the water replenishment efficiency of the pressure vessel 200, so that the liquid level in the pressure vessel 200 can be restored to or maintained at a preset liquid level as soon as possible.

[0050] In some embodiments, referring to FIG. 5 , the third delivery unit 23 includes a third delivery pump and a third delivery pipeline, and the third delivery pump is connected between the water storage tank 10 and the pressure vessel 200 through the third delivery pipeline, and is used to drive the boron water to be replenished into the pressure vessel 200 along the third delivery pipeline. The flow rate of the third delivery pump is greater than the flow rate of the second delivery pump 221, so that the pressure vessel 200 can be replenished with water faster through the third delivery pump, so that the boron water delivery flow rate of the third delivery unit 23 is greater than the boron water delivery flow rate of the second delivery unit 22, so that the third delivery unit 23 is suitable for the situation where the liquid level of the pressure vessel 200 drops rapidly. Optionally, the third delivery pump is a charging pump 2311 or a low-pressure injection pump 2312.

[0051] Further, a plurality of third delivery pumps are provided, each of which is connected to the water storage tank 10 and the pressure vessel 200 through a third delivery pipeline, and the plurality of third delivery pumps can drive the boron water to be replenished to be input into the pressure vessel 200 individually or simultaneously. It is understandable that, according to the drop in the liquid level detected by the detection unit 30, one of the third delivery pumps is selected to be used alone or multiple third delivery pumps are selected to be used simultaneously.

[0052] The provision of multiple third delivery pumps helps to increase the boron water delivery flow rate input from the third delivery unit 23 to the pressure vessel 200, ensuring that the third delivery unit 23 can raise the liquid level of the pressure vessel 200, avoiding exposure of the core and improving the safety of the nuclear reactor.

[0053] In some embodiments, the third delivery pump is selected from the upper charging pump 2311 of the RCV system. Typically, the RCV system is configured with three upper charging pumps 2311. One or more of the three upper charging pumps 2311 are selected according to the decreasing speed of the liquid level of the pressure vessel 200 detected by the detection unit 30, so that the liquid level of the pressure vessel 200 can be restored to the preset liquid level after the third delivery unit 23 replenishes water.

[0054] The third delivery pipeline 2321 uses part of the pipeline of the RIS system and part of the pipeline of the RCV system to inject the boron water to be replenished into the primary circuit pipeline. Specifically, the boron water to be replenished in the refueling water tank is sequentially input into one or more charging pumps 2311 of the RCV system through two independent pipelines of the RIS system, and then enters the pipeline of the primary circuit system through one or more of the shaft seal injection pipeline, the safety injection pipeline or the upper filling pipeline, so as to realize the water replenishment of the pressure vessel 200.

[0055] In this embodiment, the second delivery pipeline 223 and the third delivery pipeline 2321 will both pass through the charging pump 2311 of the RCV system, so that the second delivery unit 22 and the third delivery unit 23 do not deliver the boron water to be replenished to the pressure vessel 200 at the same time, which facilitates the switching of the second delivery unit 22 and the third delivery unit 23 and ensures the orderliness and stability of the water replenishment process.

[0056] In other embodiments, the second delivery pipeline 223 and the third delivery pipeline 2321 do not overlap, so that the second delivery unit 22 and the third delivery unit 23 can replenish water into the pressure vessel 200 at the same time, so as to improve the water replenishment efficiency of the pressure vessel 200, so that the liquid level in the pressure vessel 200 can be restored as soon as possible and maintained at a preset liquid level.

[0057] In some embodiments, referring to FIG6 , the third delivery pump is a low-pressure injection pump 2312 of a safety injection system (RIS). In the safety injection system, two low-pressure injection pumps 2312 are usually configured, and the two low-pressure injection pumps 2312 extract the boron water to be replenished from the water storage tank 10 through two independent pipelines. The setting of the low-pressure injection pump 2312 enables the water replenishment system 100 to replenish the pressure vessel 200 when the pressure of the boron water to be replenished is low, so as to ensure the timely and rapid water replenishment in the pressure vessel 200, improve the continuity of the water replenishment process, and ensure the establishment and operation of the recirculation condition.

[0058] In this embodiment, the third delivery pipeline 2322 uses the pipeline of the RIS system to inject the boron water to be replenished into the primary circuit pipeline. Specifically, the boron water to be replenished in the refueling water tank is sequentially passed through two independent pipelines of the RIS system to one or two low-pressure injection pumps 2312 of the RIS system, and finally enters the pressure vessel 200 through the cold end of the primary circuit to replenish the pressure vessel 200, so that the liquid level in the pressure vessel 200 rises to the preset liquid level and is maintained at or above the preset liquid level.

[0059] It is feasible that when the pressure of the boron water to be replenished in the refueling water tank is relatively high, the pressure vessel 200 is replenished with water through the charging pump 2311; and when the pressure of the boron water to be replenished in the refueling water tank is relatively low, the pressure vessel 200 is replenished with water through the low-pressure injection pump 2312, thereby ensuring the continuity of the delivery of the third delivery unit 23, and then the continuity of the water replenishment of the pressure vessel 200 by the water replenishment system 100.

[0060] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A water replenishment system for a reactor pressure vessel, characterized in that: The water replenishment system comprises: A water storage tank, the water storage tank is used to store boron water to be replenished; A conveying assembly, used for conveying the boron water to be replenished to the pressure vessel, the conveying assembly comprising a first conveying unit, a second conveying unit and a third conveying unit, the first conveying unit, the second conveying unit and the third conveying unit are all connected to the water storage tank at one end and connected to the pressure vessel at the other end, the boron water conveying flow rate of the third conveying unit is greater than the boron water conveying flow rate of the second conveying unit, and the boron water conveying flow rate of the second conveying unit is greater than the boron water conveying flow rate of the first conveying unit; and A detection unit, wherein the detection unit is used to detect the liquid level of the pressure vessel and the falling speed of the liquid level. When the detection unit detects that the liquid level of the pressure vessel is higher than a preset liquid level, the first delivery unit delivers the boron water to be replenished to the pressure vessel; when the detection unit detects that the liquid level of the pressure vessel is decreasing at a speed higher than a first preset speed and lower than a second preset speed, the second delivery unit delivers the boron water to be replenished to the pressure vessel; when the detection unit detects that the liquid level of the pressure vessel is decreasing at a speed higher than the second preset speed, the third delivery unit delivers the boron water to be replenished to the pressure vessel, and the second preset speed is greater than the first preset speed.

2. The water replenishment system for a reactor pressure vessel according to claim 1, characterized in that: When the liquid level in the pressure vessel decreases at a rate higher than the first preset speed and lower than the second preset speed, the amount of liquid lost in the pressure vessel is less than the amount of boron water delivered by the second delivery unit; when the liquid level in the pressure vessel decreases at a rate higher than the second preset speed, the amount of liquid lost in the pressure vessel is greater than the amount of boron water delivered by the second delivery unit.

3. The water replenishment system for a reactor pressure vessel according to claim 1, characterized in that: The first delivery unit includes a first delivery pump, a first valve and a first delivery pipeline. The first delivery pump is connected to the water storage tank through the first delivery pipeline, and is used to drive the boron water to be replenished into the pressure vessel along the first delivery pipeline. The first valve is connected between the first delivery pump and the pressure vessel through the first delivery pipeline. The first valve can adjust the flow rate of the boron water to be replenished input into the pressure vessel through the first delivery pump.

4. The water replenishment system for a reactor pressure vessel according to claim 3, characterized in that: The second delivery unit includes a second delivery pump, a second valve and a second delivery pipeline. The second delivery pump is connected to the water storage tank through the second delivery pipeline and is used to drive the boron water to be replenished into the pressure vessel along the second delivery pipeline. The second valve is connected between the second delivery pump and the pressure vessel through the second delivery pipeline. The second valve is used to control the conduction or blocking between the second delivery pump and the pressure vessel.

5. The water replenishment system for a reactor pressure vessel according to claim 4, characterized in that: The flow rate of the second valve is greater than the flow rate of the first valve; and / or the flow rate of the second delivery pump is greater than the flow rate of the first delivery pump.

6. The water replenishment system for a reactor pressure vessel according to claim 4, characterized in that: The length of the second delivery line is shorter than the length of the first delivery line.

7. The water replenishment system for a reactor pressure vessel according to claim 4, characterized in that: The third delivery unit includes a third delivery pump and a third delivery pipeline. The third delivery pump is connected between the water storage tank and the pressure vessel through the third delivery pipeline, and is used to drive the boron water to be replenished into the pressure vessel along the third delivery pipeline. The flow rate of the third delivery pump is greater than the flow rate of the second delivery pump.

8. The water replenishment system for a reactor pressure vessel according to claim 7, characterized in that: There are multiple third delivery pumps, each of which is connected between the water storage tank and the pressure vessel through the third delivery pipeline. The multiple third delivery pumps can drive the boron water to be replenished to be input into the pressure vessel individually or simultaneously.

9. The water replenishment system for a reactor pressure vessel according to claim 7, characterized in that: The third delivery pump is a charging pump or a low-pressure injection pump.

10. The water replenishment system for a reactor pressure vessel according to claim 1, characterized in that: The first conveying unit and the second conveying unit do not convey the boron water to be replenished to the pressure container at the same time.

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