Reactor chamber water injection cooling system and method

Abstract

The invention discloses a reactor chamber water injection cooling system and method.The outer wall face of a reactor pressure vessel is provided with an outer-layer heat preservation vessel, a sealed chamber is formed between the reactor pressure vessel and the outer-layer heat preservation vessel, and the reactor chamber water injection cooling system comprises two rows of circulation loops; each of the two columns of circulation loops comprises a high-position cooling water tank, a water injection valve group and a first water collecting device, an outlet of the first water collecting device is communicated with an inlet of the high-position cooling water tank, and a water source outside the containment is communicated with the high-position cooling water tank; a bottom outlet of the high-level cooling water tank is communicated with an inlet of a cavity between the reactor pressure vessel and the outer-layer heat preservation vessel, and an outlet of the cavity between the reactor pressure vessel and the outer-layer heat preservation vessel is communicated with a sprayer in the high-level cooling water tank; and the outlet of the second water collecting device is communicated with the inlet of the reactor cabin through the water tank in the containment vessel. The system and the method can meet the long-term cooling in a design basis exceeding accident.

Description

Technical Field

[0001] The invention belongs to the field of waste heat removal of pressure vessels in nuclear reactor accident conditions, and relates to a reactor chamber water injection cooling system and method. Background Art

[0002] The design of nuclear reactors needs to consider a series of accidents such as power outages and LOCA, which are called design basis accidents. Although the probability of a design basis accident is extremely small, when a design basis accident occurs, the safety level system can rely on active or passive means to ensure the core cooling, reactivity control and radioactive containment of the nuclear reactor to ensure that the core is not damaged. However, for the beyond-design basis accident of core melting, although the probability of its occurrence is several orders of magnitude lower than that of the design basis accident, the severity of the consequences of the accident still requires consideration of preventive measures. The current fourth-generation advanced reactors use a graphite-moderated helium cooling design, and there is no problem of core melting. However, for pressurized water reactors, core cooling, pressure vessel flooding and retention in the reactor after the reactor core melts are particularly important.

[0003] In order to solve the above problem, a certain type of pressurized water reactor adopts the solution of using the concrete compartment where the pressure vessel is located as a spare water pool. In the event of an extreme beyond-design basis accident, the water from the refueling pool in the containment is injected into the outer surface of the cooling pressure vessel to cool the reactor and prevent the melted core from melting through the pressure vessel. Due to the barrier of the insulation layer on the outer surface of the pressure vessel, it is difficult for the injected water to enter the insulation layer, and the cooling capacity of the outer surface of the pressure vessel is limited, and the retention capacity of the melted core is insufficient.

[0004] A new type of pressurized water reactor has made improvements on the above basis. The water in the water tank is injected into the outer insulation layer of the pressure vessel by gravity. This can avoid the problem of insufficient cooling capacity caused by the insulation layer blocking. However, the insulation layer also blocks the flow of cooling water. Especially in the absence of forced circulation, after the water inside the water tank is consumed, if there is a lack of driving equipment, the cooling water will be lost and cannot meet the long-term cooling requirements under beyond the design basis accident. Summary of the invention

[0005] The object of the present invention is to overcome the above-mentioned shortcomings of the prior art and to provide a reactor chamber water injection cooling system and method, which can meet the long-term cooling requirements under beyond-design basis accidents.

[0006] To achieve the above-mentioned purpose, the reactor chamber water injection cooling system of the present invention comprises a water source outside the containment, a containment, a reactor pressure vessel arranged inside the containment, a water tank inside the containment, a second water collecting device, a reactor compartment and a reactor chamber water injection cooling system;

[0007] An outer thermal insulation container is installed on the outer wall surface of the reactor pressure vessel, and a sealed chamber is formed between the reactor pressure vessel and the outer thermal insulation container. The reactor pressure vessel is located in the reactor compartment;

[0008] The reactor chamber water injection cooling system includes two circulation loops, each of which includes a high-level cooling water tank, a water injection valve group and a first water collecting device. The outlet of the first water collecting device is connected to the inlet of the high-level cooling water tank, the water source outside the containment is connected to the high-level cooling water tank, the bottom outlet of the high-level cooling water tank is connected to the inlet of the chamber between the reactor pressure vessel and the outer insulation container, the outlet of the chamber between the reactor pressure vessel and the outer insulation container is connected to the sprinkler in the high-level cooling water tank, and the outlet of the second water collecting device is connected to the inlet of the reactor compartment through the water tank inside the containment.

[0009] Furthermore, the bottom outlet of the high-level cooling water tank is connected to the inlet of the chamber between the reactor pressure vessel and the outer insulation container through the water injection valve group.

[0010] Furthermore, the water injection valve group in the first circulation loop is composed of two parallel pneumatic valves and two parallel electric valves connected in series; the water injection valve group in the second circulation loop is composed of two identical groups of pneumatic valves and electric valves first connected in parallel and then in series.

[0011] Furthermore, the outlet of the chamber between the reactor pressure vessel and the outer insulation container is connected to the sprayer in the high-level cooling water tank via the vacuum pump inlet valve, the vacuum pump, and the vacuum pump outlet check valve in sequence.

[0012] Furthermore, the outlet of the water tank in the containment vessel is connected to the inlet of the reactor compartment through the reactor cavity water injection valve.

[0013] Furthermore, the position of the first water collecting device is higher than the high-level cooling water tank, and the position of the high-level cooling water tank is higher than the reactor pressure vessel;

[0014] The positions of the second water collecting device, the water tank in the containment and the reactor compartment are lowered in sequence.

[0015] The reactor chamber water injection cooling method of the present invention includes the working conditions before the reactor is started, the working conditions of the reactor being in normal operation, the working conditions of the reactor being abnormal and the power supply being normal, and the working conditions of the reactor being abnormal and the power supply being lost.

[0016] Furthermore, before the reactor is started, the water injection valve group and the reactor cavity water injection valve group are both in a closed state, and the high-level cooling water tank is filled with water to a rated height using a water source outside the containment vessel; the vacuum pump inlet valves in the two circulation loops are opened, and the vacuum pumps in the two circulation loops are started, and after the chamber between the reactor pressure vessel and the outer insulation container is evacuated to a preset vacuum value, the vacuum pump in the second circulation loop is shut down, the vacuum pump inlet valve in the second circulation loop is closed, and the vacuum pump in the first circulation loop is continuously operated to ensure that the vacuum value in the chamber is stable.

[0017] Furthermore, when the reactor is abnormal and the power supply is normal, when the reactor compartment needs to be injected with water for cooling, the injection valve groups in the two circulation loops are opened, and the water in the high-level cooling water tank is injected into the chamber;

[0018] When power is available, the vacuum pump realizes forced circulation of water in the chamber between the reactor pressure vessel and the outer insulation container and in the high-level cooling water tank;

[0019] The low-temperature water in the high-level cooling water tank flows through the chamber between the reactor pressure vessel and the outer insulation container, heats up, and then enters the high-level cooling water through the sprinkler;

[0020] When the water level in the high-level cooling water tank drops, water is replenished from the water source outside the containment;

[0021] As the water temperature in the high-level cooling water tank gradually increases, part of the water vaporizes, and the generated steam condenses in the containment, is then collected by the first water collecting device, and then returns to the high-level cooling water tank to re-enter the circulation.

[0022] Furthermore, when the reactor is abnormal and power is lost, when water needs to be injected into the reactor compartment for cooling, due to power loss, the two pneumatic valves in the water injection valve group in the first circulation loop are opened, and all valves in the water injection valve group in the second circulation loop are opened;

[0023] Since the chamber between the reactor pressure vessel and the outer insulation container is in a vacuum state, the water in the high-level cooling water tank is injected into the chamber between the reactor pressure vessel and the outer insulation container at the beginning of the accident. The water in the high-level cooling water tank enters the chamber between the reactor pressure vessel and the outer insulation container by gravity injection;

[0024] The water injected into the chamber between the reactor pressure vessel and the outer insulation container is heated and then enters the high-level cooling water tank for mixed cooling;

[0025] In the case of power failure, cooling water is injected through the high-level cooling water tank to meet the cooling demand of the outer surface of the reactor pressure vessel;

[0026] As the water level in the high-level cooling water tank gradually decreases and the temperature gradually increases, part of the water in the high-level cooling water tank vaporizes. After the generated steam condenses in the containment, part of the condensed water is collected by the first water collecting device and then returned to the high-level cooling water tank. The other part of the condensed water is collected by the second water collecting device and then enters the water tank in the containment. It is then injected into the reactor compartment through the reactor cavity water injection valve group, thereby flooding and cooling the reactor pressure vessel and the outer insulation container, ensuring that the damaged core is retained in the reactor.

[0027] The present invention has the following beneficial effects:

[0028] The reactor chamber water injection cooling system and method described in the present invention adopts a vacuum insulation method during specific operation, eliminates the conventional island insulation layer, improves the heat exchange efficiency, and ensures rapid water filling and sufficient cooling of the pressure vessel under extreme accidents. In addition, the present invention sets up two circulation loops, and the water injection valve group adopts a redundant and diverse design. In addition, a high-level cooling water tank is used as the first water source, a water tank inside the containment is used as the second water source, a first water collection device and a second water collection device are used to collect condensed water inside the containment as the third water source, and a water source outside the containment is used as the fourth water source. The four-fold water source ensures that the water volume in the containment is not reduced while also ensuring long-term cooling of the reactor pressure vessel, ensuring that the melted core is retained in the pile. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 It is a structural diagram of the present invention.

[0031] Among them, 1 is the reactor pressure vessel, 2 is the outer insulation container, 3 is the support, 4 is the reactor compartment, 5 is the vacuum pump inlet valve, 6 is the vacuum pump, 7 is the vacuum pump outlet check valve, 8 is the high-level cooling water tank, 9 is the sprinkler, 10 is the water injection valve group, 11 is the water source outside the containment, 12 is the first water collection device, 13 is the second water collection device, 14 is the water tank inside the containment, 15 is the reactor cavity water injection valve group, and 16 is the containment. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0034] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0035] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0036] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0037] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0040] Embodiment 1

[0041] refer to Figure 1 The reactor chamber water injection cooling system of the present invention comprises a reactor pressure vessel 1, an outer insulation container 2, a support 3, a reactor compartment 4, a vacuum pump inlet valve 5, a vacuum pump 6, a vacuum pump outlet check valve 7, a high-level cooling water tank 8, a sprinkler 9, a water injection valve group 10, a water source outside the containment 11, a first water collection device 12, a second water collection device 13, a water tank inside the containment 14, a reactor cavity water injection valve group 15 and a containment 16;

[0042] An outer insulation container 2 is installed on the outer wall surface of the reactor pressure vessel 1, and a sealed chamber is formed between the reactor pressure vessel 1 and the outer insulation container 2. The support 3 is located between the reactor pressure vessel 1 and the outer insulation container 2, and the reactor pressure vessel 1 is located in the reactor compartment 4.

[0043] The reactor chamber water injection cooling system includes two circulation loops, each of which includes a vacuum pump inlet valve 5, a vacuum pump 6, a vacuum pump outlet check valve 7, a high-level cooling water tank 8, a sprinkler 9, a water injection valve group 10 and a first water collecting device 12; the outlet of the first water collecting device 12 is connected to the inlet of the high-level cooling water tank 8, the water source 11 outside the containment is connected to the high-level cooling water tank 8, the bottom outlet of the high-level cooling water tank 8 is connected to the inlet of the chamber between the reactor pressure vessel 1 and the outer insulation container 2 through the water injection valve group 10, and the outlet of the chamber between the reactor pressure vessel 1 and the outer insulation container 2 is connected to the sprinkler 9 in the high-level cooling water tank 8 through the vacuum pump inlet valve 5, the vacuum pump 6, the vacuum pump outlet check valve 7 in turn.

[0044] The outlet of the second water collecting device 13 is connected to the inlet of the water tank 14 in the containment vessel, and the outlet of the water tank 14 in the containment vessel is connected to the inlet of the reactor compartment 4 through the reactor cavity water injection valve 15 .

[0045] The reactor pressure vessel 1, the outer insulation container 2, the support 3, the reactor compartment 4, the vacuum pump inlet valve 5, the vacuum pump 6, the vacuum pump outlet check valve 7, the high-level cooling water tank 8, the sprinkler 9, the water injection valve group 10, the first water collecting device 12, the second water collecting device 13, the water tank inside the containment 14 and the reactor cavity water injection valve group 15 are all located inside the containment 16, and the water source outside the containment 11 is located outside the containment 16.

[0046] As an implementation mode of the present invention, two rows of circulation loops are symmetrically arranged within the containment vessel 16, and the design capacity of a single row is 100%.

[0047] As an embodiment of the present invention, a water source 11 outside the containment shell replenishes water to the high-level cooling water tank 8. The normal replenishment water source is demineralized water, and the emergency replenishment water source can be fire water, industrial water, mobile water tankers and other available fresh water sources.

[0048] As an embodiment of the present invention, the first water collecting device 12 is located higher than the high-position cooling water tank 8 , and the high-position cooling water tank 8 is located higher than the reactor pressure vessel 1 .

[0049] As an embodiment of the present invention, the water injection valve group 10 in the first circulation loop is composed of two parallel pneumatic valves and two parallel electric valves connected in series; the water injection valve group 10 in the second circulation loop is composed of two groups of identical pneumatic valves and electric valves that are first connected in parallel and then in series, wherein all the electric valves maintain their positions when power is lost, and all the pneumatic valves open when air and power are lost.

[0050] The positions of the second water collecting device 13, the water tank 14 in the containment vessel and the reactor compartment 4 are lowered in sequence.

[0051] Under accident conditions, the high-level cooling water tank 8, as the first water source, first quickly fills the chamber between the reactor pressure vessel 1 and the outer insulation container 2 under the action of vacuum, and the high-temperature water or steam is partially recovered by the high-level cooling water tank 8 and re-enters the circulation. The water tank 14 in the containment serves as the second water source. When the water level of the high-level cooling water tank 8 is low, the reactor compartment 4 is flooded to continuously cool the reactor pressure vessel 1. The first water collection device 12 and the second water collection device 13 collect the condensed water inside the containment 16 as the third water source, and recycle it after the high-temperature water vaporizes and recondenses, ensuring that the water volume in the containment 16 does not decrease. The water source 11 outside the containment serves as the fourth water source, and replenishes water in the containment 16 when possible. The four-fold water source ensures that the water volume in the containment 16 does not decrease, and also ensures the long-term cooling of the reactor pressure vessel 1, ensuring that the melted core is retained in the reactor.

[0052] Embodiment 2

[0053] The reactor chamber water injection cooling method of the present invention comprises the following steps:

[0054] 1. Before the reactor starts

[0055] 11) Before the reactor is started, the water injection valve group 10 and the reactor cavity water injection valve group 15 are both in a closed state. The high-level cooling water tank 8 is filled with water to the rated height using the water source 11 outside the containment.

[0056] 12) Open the vacuum pump inlet valves 5 in both circulation loops, start the vacuum pumps 6 in both circulation loops, and after the chamber between the reactor pressure vessel 1 and the outer insulation container 2 is evacuated to a preset vacuum value, stop the vacuum pump 6 in the second circulation loop, close the vacuum pump inlet valve 5 in the second circulation loop, and keep the vacuum pump 6 in the first circulation loop running to ensure that the above vacuum value is stable.

[0057] 2. Reactor is operating normally

[0058] 21) The vacuum pump 6 in the second circulation loop is stopped, and the vacuum pump inlet valve 5 in the second circulation loop is closed; the vacuum pump 6 in the first circulation loop is continuously operated to ensure the above vacuum value is stable. The vacuum pump 6 in the second circulation loop is in automatic standby state, and is automatically started according to the stop signal or vacuum low signal of the vacuum pump 6 in the first circulation loop, or is manually started.

[0059] 22) Open the electric valve in the water injection valve group 10 in the first circulation loop and close the pneumatic valve; close both the electric valve and the pneumatic valve in the water injection valve group 10 in the second circulation loop.

[0060] 3. Reactor is in abnormal condition, power supply is normal

[0061] 31) When the abnormal operating condition of the reactor requires water injection for cooling of the reactor compartment 4, the water injection valve groups 10 in the two circulation loops are opened.

[0062] 32) Since the chamber between the reactor pressure vessel 1 and the outer insulation container 2 is in a vacuum state, the water in the high-level cooling water tank 8 can be quickly injected into the chamber at the early stage of an accident.

[0063] 33) When power is available, the vacuum pump 6 can realize forced circulation of water in the chamber between the reactor pressure vessel 1 and the outer insulation container 2 and the high-level cooling water tank 8 to improve the cooling efficiency. One or two vacuum pumps 6 can be started according to the situation.

[0064] 34) The low-temperature water in the high-level cooling water tank 8 flows through the chamber between the reactor pressure vessel 1 and the outer insulation container 2 and is heated up, and then enters the high-level cooling water tank 8 through the sprinkler 9 to avoid excessive vaporization of high-temperature water and realize partial water recycling.

[0065] 35) After the water level in the high-level cooling water tank 8 is lowered, water is replenished through the water source 11 outside the containment.

[0066] 36) As the water temperature in the high-level cooling water tank 8 gradually increases, part of the water vaporizes, and the generated steam condenses in the containment vessel 16, is then collected by the first water collecting device 12, and then returns to the high-level cooling water tank 8 to re-enter the cycle.

[0067] 4. Abnormal reactor conditions plus power loss

[0068] 41) When the reactor needs to be cooled by water injection into the reactor compartment 4 under abnormal operating conditions, due to power loss, the two pneumatic valves in the water injection valve group 10 in the first circulation loop are opened, and all valves in the water injection valve group 10 in the second circulation loop are opened.

[0069] 42) Since the chamber between the reactor pressure vessel 1 and the outer insulation container 2 is in a vacuum state, the water in the high-level cooling water tank 8 can be quickly injected into the chamber between the reactor pressure vessel 1 and the outer insulation container 2 at the initial stage of the accident. The water in the high-level cooling water tank 8 enters the chamber between the reactor pressure vessel 1 and the outer insulation container 2 by gravity injection.

[0070] 43) The water injected into the chamber between the reactor pressure vessel 1 and the outer insulation container 2 is heated and then enters the high-level cooling water tank 8 for mixed cooling.

[0071] 44) Since the single-row system is 100% designed, in the case of power failure, the cooling water injected through the high-level cooling water tank 8 can fully meet the cooling demand of the outer surface of the reactor pressure vessel 1.

[0072] 45) As the water level in the high-level cooling water tank 8 gradually decreases and the temperature gradually increases, part of the water in the high-level cooling water tank 8 vaporizes. After the generated steam condenses in the containment vessel 16, part of the condensed water is collected by the first water collecting device 12, and then returns to the high-level cooling water tank 8 and re-enters the circulation.

[0073] 46) Another part of the condensed water is collected by the second water collecting device 13, and then enters the water tank 14 in the containment, and then is injected into the reactor compartment 4 through the reactor cavity water injection valve group 15, so as to flood and cool the reactor pressure vessel 1 and the outer insulation container 2, and ensure that the damaged core is retained in the reactor.

[0074] 47) The water source 11 outside the containment vessel serves as a possible backup water source and can replenish water inside the containment vessel 16 if conditions permit.

[0075] 48) When the water source 11 outside the containment is completely unavailable, the water capacity of the two high-level cooling water tanks 8 and the water tank 14 inside the containment can meet the long-term cooling of the reactor pressure vessel 1. The long-term cooling water source collects condensed water inside the containment 16 through the first water collection device 12 and the second water collection device 13, and then injects it through gravity.

[0076] 49) After the unit resumes power supply, the long-term cooling function of the reactor pressure vessel 1 under the design conditions can be met through external water supply forced cooling or long-term circulating cooling.

[0077] 410) The high-level cooling water tank 8 is used as the first water source, the water tank 14 in the containment is used as the second water source, the first water collecting device 12 and the second water collecting device 13 collect condensed water inside the containment 16 as the third water source, and the water source 11 outside the containment is used as the fourth water source. The four-fold water source ensures that the water volume in the containment 16 is not reduced, and also ensures the long-term cooling of the reactor pressure vessel 1, ensuring that the melted core is retained in the reactor.

[0078] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0079] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0080] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A reactor chamber water injection cooling system, characterized in that: It comprises a water source outside the containment (11), a containment (16), a reactor pressure vessel (1) arranged inside the containment (16), a water tank (14) inside the containment, a second water collecting device (13), a reactor compartment (4) and a reactor chamber water injection cooling system; An outer thermal insulation container (2) is installed on the outer wall surface of the reactor pressure vessel (1), a sealed chamber is formed between the reactor pressure vessel (1) and the outer thermal insulation container (2), and the reactor pressure vessel (1) is located in a reactor compartment (4); The reactor chamber water injection cooling system comprises two circulation loops, each of which comprises a high-level cooling water tank (8), a water injection valve group (10) and a first water collecting device (12); the outlet of the first water collecting device (12) is connected to the inlet of the high-level cooling water tank (8); the water source (11) outside the containment is connected to the high-level cooling water tank (8); the bottom outlet of the high-level cooling water tank (8) is connected to the inlet of the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2); the outlet of the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) is connected to a sprinkler (9) in the high-level cooling water tank (8); and the outlet of the second water collecting device (13) is connected to the inlet of the reactor chamber (4) via a water tank (14) inside the containment.

2. The reactor chamber water injection cooling system according to claim 1, characterized in that: The bottom outlet of the high-level cooling water tank (8) is connected to the inlet of the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) through a water injection valve group (10).

3. The reactor chamber water injection cooling system according to claim 2, characterized in that: The water injection valve group (10) in the first circulation loop is composed of two pneumatic valves connected in parallel and two electric valves connected in parallel in series; the water injection valve group (10) in the second circulation loop is composed of two identical groups of pneumatic valves and electric valves connected in parallel and then in series.

4. The reactor chamber water injection cooling system according to claim 3, characterized in that: The outlet of the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) is connected to a sprayer (9) in a high-level cooling water tank (8) via a vacuum pump inlet valve (5), a vacuum pump (6), and a vacuum pump outlet check valve (7) in sequence.

5. The reactor chamber water injection cooling system according to claim 4, characterized in that: The outlet of the water tank (14) in the containment vessel is connected to the inlet of the reactor compartment (4) via the reactor cavity water injection valve (15).

6. The reactor chamber water injection cooling system according to claim 1, characterized in that: The first water collecting device (12) is located higher than the high-position cooling water tank (8), and the high-position cooling water tank (8) is located higher than the reactor pressure vessel (1); The positions of the second water collecting device (13), the water tank (14) in the containment vessel and the reactor compartment (4) are lowered in sequence.

7. A method for cooling a reactor chamber by injecting water, characterized in that: The reactor chamber water injection cooling system according to claim 5 includes the operating conditions before reactor startup, the operating conditions of normal reactor operation, the operating conditions of abnormal reactor and normal power supply, and the operating conditions of abnormal reactor and power loss.

8. The method for cooling a reactor chamber by injecting water according to claim 7, characterized in that: Under the working condition before the reactor is started, the water injection valve group (10) and the reactor cavity water injection valve group (15) are both in a closed state, and the high-level cooling water tank (8) is filled with water to a rated height using a water source (11) outside the containment vessel; the vacuum pump inlet valves (5) in the two circulation loops are both opened, and the vacuum pumps (6) in the two circulation loops are started, and after the chamber between the reactor pressure vessel (1) and the outer insulation container (2) is evacuated to a preset vacuum value, the vacuum pump (6) in the second circulation loop is stopped, the vacuum pump inlet valve (5) in the second circulation loop is closed, and the vacuum pump (6) in the first circulation loop is continuously operated to ensure that the vacuum value in the chamber is stable.

9. The reactor chamber water injection cooling method according to claim 7, characterized in that: When the reactor is abnormal and the power supply is normal, when the reactor compartment (4) needs to be injected with water for cooling, the injection valve groups (10) in the two circulation loops are opened, and the water in the high-level cooling water tank (8) is injected into the chamber; When power is available, the vacuum pump (6) realizes forced circulation of water in the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) and the high-level cooling water tank (8); The low-temperature water in the high-level cooling water tank (8) flows through the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) and is heated, and then enters the high-level cooling water tank (8) through the sprayer (9); When the water level in the high-level cooling water tank (8) decreases, water is replenished through a water source (11) outside the containment vessel; As the water temperature in the high-level cooling water tank (8) gradually increases, part of the water vaporizes, and the generated steam condenses in the containment vessel (16), is then collected by the first water collecting device (12), and then returns to the high-level cooling water tank (8) to re-enter the circulation.

10. The reactor chamber water injection cooling method according to claim 7, characterized in that: When the reactor is abnormal and power is lost, when water needs to be injected into the reactor compartment (4) for cooling, due to the power loss, the two pneumatic valves in the water injection valve group (10) in the first circulation loop are opened, and all valves in the water injection valve group (10) in the second circulation loop are opened; Since the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) is in a vacuum state, the water in the high-level cooling water tank (8) is injected into the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) at the initial stage of the accident, and the water in the high-level cooling water tank (8) enters the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) by gravity injection; The water injected into the chamber between the reactor pressure vessel (1) and the outer thermal insulation container (2) is heated and then enters the high-level cooling water tank (8) for mixed cooling; In the case of power failure, cooling water is injected through the high-level cooling water tank (8) to meet the cooling demand of the outer surface of the reactor pressure vessel (1); As the water level in the high-level cooling water tank (8) gradually decreases and the temperature gradually increases, part of the water in the high-level cooling water tank (8) vaporizes, and the generated steam condenses in the containment vessel (16). Part of the condensed water is collected by the first water collecting device (12) and then returned to the high-level cooling water tank (8). The other part of the condensed water is collected by the second water collecting device (13) and then enters the water tank (14) in the containment vessel, and then is injected into the reactor compartment (4) through the reactor cavity water injection valve group (15), thereby achieving the flooding and cooling of the reactor pressure vessel (1) and the outer thermal insulation container (2), and ensuring that the damaged core is retained in the reactor.

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