Nuclear reactor starting heating device

Abstract

The invention provides a nuclear reactor starting heating device which comprises at least one connecting pipe and a matching pipe, the connecting pipe is provided with a first mounting end and a second mounting end, the first mounting end is connected with a pressure vessel, and the second mounting end extends into a cylinder arranged above a reactor core; the matching pipe is connected with the second mounting end of the connecting pipe, and at least one discharge hole is formed in the matching pipe; when the nuclear reactor is started to heat, a hot coolant introduced from the outer side of the nuclear reactor is conveyed to the matching pipe through the connecting pipe and flows out through the discharge hole, so that the density difference between the rising main coolant in the barrel and the main coolant in the annular space is formed, and the main coolant is driven to circularly pass through the reactor core. According to the heating device, the hot coolant is introduced from the outer side of the nuclear reactor and conveyed to the position above the reactor core through the connecting pipe and the matching pipe, so that the density difference between the main coolant in the ascending pipe and the coolant in the annular space is caused, and the main coolant is driven to pass through the reactor core in a circulating manner.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear reactor startup, and in particular to a nuclear reactor startup heating device. Background Art

[0002] A heater of a nuclear reactor startup system is configured to add heat to a primary coolant contained in a reactor vessel prior to initializing the reactor to achieve reactor criticality, wherein the heater is configured to add heat to a riser located at a height below that of a radiator to induce a density difference between the primary coolant in the riser and the primary coolant in the annular space, thereby driving natural circulation of the primary coolant through the reactor core.

[0003] The current heater is an integral block-shaped heating structure, with its input device and control device placed outside the reactor vessel, which involves problems such as the sealing of the reactor vessel takeover pipe. Moreover, the heating device itself is large in size, which will cause convection conflict with the rising main coolant. The layout position, fixing method and installation positioning of the heater are all difficult.

[0004] Based on this, the inventor of the present application proposes a nuclear reactor startup heating device in order to solve the above technical problems. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a nuclear reactor startup heating device in order to overcome the defects in the prior art that the heater input device and the control device are externally placed, which causes the sealing problem, and the convection between the heater itself and the main coolant affects the circulation efficiency of the main coolant.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The present invention provides a nuclear reactor startup heating device, which is characterized in that it comprises:

[0008] at least one connecting pipe, the connecting pipe having a first mounting end and a second mounting end, the first mounting end being connected to the pressure vessel, and the second mounting end extending into a cylinder disposed above the core;

[0009] A matching pipe is connected to the second mounting end of the connecting pipe, and at least one discharge hole is provided on the matching pipe; wherein,

[0010] When the nuclear reactor is started and heated, the hot coolant introduced from the outside of the nuclear reactor is transported to the matching pipe through the connecting pipe and flows out through the discharge hole to form a density difference between the rising main coolant in the cylinder and the main coolant in the annular space, thereby driving the main coolant to circulate through the core.

[0011] According to one embodiment of the present invention, the matching tube is an annular tube, and one end of the matching tube is arranged close to the inner wall of the cylinder.

[0012] According to one embodiment of the present invention, one end of the matching tube is connected to the inner wall of the cylinder.

[0013] According to an embodiment of the present invention, at least two snap fasteners are arranged at intervals on the outer circumference of the matching tube, and opposite ends of the snap fasteners are respectively connected to the inner wall of the cylinder.

[0014] According to an embodiment of the present invention, the first installation end of the connecting pipe is connected to a connecting pipe provided on the pressure vessel.

[0015] According to one embodiment of the present invention, at least two discharge holes are formed on a side of the matching tube away from the core, and the at least two discharge holes are spaced apart along the circumference of the matching tube.

[0016] According to one embodiment of the present invention, the discharge hole penetrates the matching tube along the axial direction of the pressure container.

[0017] According to an embodiment of the present invention, the number of the discharge holes is at least two, and at least one of the discharge holes is opened on the inner side of the matching tube away from the cylinder.

[0018] According to an embodiment of the present invention, one end of the matching tube is welded to the connecting tube, and one end of the connecting tube is attached to the inner wall of the cylinder.

[0019] According to one embodiment of the present invention, the number of the connecting tubes is at least two, and at least two connecting tubes are evenly spaced around the circumference of the matching tube.

[0020] According to an embodiment of the present invention, the number of the matching tubes is at least two, and at least two matching tubes are arranged at intervals along the length extension direction of the connecting tube.

[0021] The positive and progressive effects of the present invention are:

[0022] The nuclear reactor startup heating device of the present invention adopts a connecting pipe and a matching pipe for cooperation. The first installation end of the connecting pipe is connected to the pressure vessel, and the matching pipe is installed to the second installation end. The hot coolant is introduced from the outside of the nuclear reactor and transported to the top of the core through the connecting pipe and the matching pipe, thereby causing a density difference between the main coolant in the riser and the coolant in the annular space, thereby driving the main coolant to circulate through the reactor core.

[0023] The core is started quickly by using a mechanical structure to transport hot coolant, without the need to heat the coolant above the core like traditional heaters. This eliminates the need for external input and control devices of traditional heaters, making the sealing problem easier to solve. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0025] Figure 1 This is a schematic diagram of the nuclear reactor startup heating device and the pressure vessel being installed in coordination with each other;

[0026] Figure 2 It is an axonometric diagram of the nuclear reactor startup heating device of the present invention;

[0027] Figure 3 for Figure 2 A top view of the middle matching tube;

[0028] Figure 4 It is a schematic diagram of the installation of an embodiment of the matching pipe and the upper supporting tube group of the present invention.

[0029] 1. Connecting pipe; 11. First mounting end; 12. Second mounting end;

[0030] 2. Pressure vessel; 21. Core; 22. Cylinder;

[0031] 3. Matching pipe; 31. Discharge hole; 32. Fastener;

[0032] 4. Rising main coolant;

[0033] 5. Main coolant in annular space;

[0034] 6. Heat exchanger. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0037] Please refer to Figures 1 to 4 The present invention provides a nuclear reactor startup heating device, comprising at least one connecting pipe 1 and a matching pipe 3, wherein the connecting pipe 1 has a first mounting end 11 and a second mounting end 12, wherein the first mounting end 11 is connected to the pressure vessel 2, and the second mounting end 12 extends into a cylinder 22 disposed above the core 21. The matching pipe 3 is connected to the second mounting end 12 of the connecting pipe 1, and at least one discharge hole 31 is provided on the matching pipe 3. When the nuclear reactor is started for heating, the hot coolant introduced from the outside of the nuclear reactor is transported to the matching pipe 3 through the connecting pipe 1 and flows out through the discharge hole 31, so as to form a density difference between the rising primary coolant 4 in the cylinder 22 and the primary coolant in the annular space, thereby driving the primary coolant to circulate through the core 21.

[0038] When the nuclear reactor is in a critical state, the startup of a cyclic nuclear reactor will cause a large amount of cold water to flow into the core 21. When the control rods are initially removed from the core 21, the rapid cooling of the fluid moderator or coolant may cause a rapid increase in the power of the reactor core 21 or a power abnormal surge. If the power abnormal surge is too large, the control rods can be lowered to reduce the heat generated by the core 21. The cyclic removal and insertion of the control rods increases the complexity and the time required to reach the operating temperature, and ultimately leads to a longer startup period and additional supervision during the operation of the power module assembly.

[0039] Conventional reactors are equipped with a heater above the core 21 to shorten the startup time, but the input device and control device of the heater are placed outside the reactor vessel, which brings about sealing problems between the reactor and the reactor. Because the heater is only used during the startup phase of the reactor, the structure of the later heater will occupy the rising space of the main coolant.

[0040] Moreover, the heater is electrically heated, and if it is in the pressure vessel 2 for a long time, it will bring potential safety hazards to the reactor and affect the safety of the reactor.

[0041] Based on this, the heat source of the present invention uses hot coolant, and the hot coolant is introduced from outside the reactor through the connecting pipe 1 and discharged through the discharge hole 31 of the matching pipe 3. When the nuclear reactor is started for heating, there is a certain density difference between the rising main coolant 4 in the cylinder 22 and the main coolant 5 in the annular space, which can drive the main coolant to circulate through the core 21, shorten the startup time of the core 21, and improve the safety of the heating device.

[0042] It can be known that the cylinder 22 can be a hanging basket cylinder or an upper supporting skirt, which is not limited here.

[0043] Please refer to Figure 2 and Figure 3 The matching tube 3 is an annular tube, and one end is arranged close to the inner wall of the cylinder 22.

[0044] The matching pipe 3 is set as an annular pipe, so that the annular pipe will not occupy too much rising space of the main coolant. In addition, one end of the annular pipe is set close to the inner wall of the cylinder 22, which, on the one hand, reduces the contact area between the annular pipe and the rising main coolant 4, avoiding excessive influence on the circulation of the rising main coolant 4; on the other hand, the cylinder 22 can also play the role of limiting support for the annular pipe, improving the stability of the annular pipe structure itself.

[0045] Furthermore, one end of the matching tube 3 is connected to the inner wall of the cylinder 22 .

[0046] It can be known that one end of the matching tube 3 and the cylinder 22 can be connected by welding, thereby ensuring the stability of the matching tube 3 in use.

[0047] In some other embodiments, please refer to Figure 4 At least two snap-fitting members 32 are arranged at intervals on the outer circumference of the matching tube 3 , and the opposite ends of the snap-fitting members 32 are respectively connected to the inner wall of the cylinder 22 .

[0048] That is, the fitting tube 3 is clamped with the fastener 32, and the fastener 32 is connected to the cylinder 22. The connection method includes but is not limited to welding, and the welding of the fastener 32 and the cylinder 22 is used as an example for explanation. Threaded connectors or buckles can also be used for connection.

[0049] Please continue to refer to Figure 1 The first installation end 11 of the connecting pipe 1 is connected to the connecting pipe arranged on the pressure vessel 2 .

[0050] That is, a connecting pipe (not shown) is provided on the pressure container 2, and the connecting pipe 1 can be sealed and inserted into the connecting pipe, thus satisfying the installation and sealing requirements of the connecting pipe 1.

[0051] Please refer to Figure 2 and Figure 3 At least two discharge holes 31 are opened on the side of the matching tube 3 away from the core 21 , and the at least two discharge holes 31 are arranged at intervals along the circumference of the matching tube 3 .

[0052] That is, a hole is opened above the matching tube 3, but the discharge hole 31 does not penetrate the matching tube 3. The hot coolant discharged from the discharge hole 31 flows directly in the direction away from the core 21, and the density difference between the hot coolant and the cold coolant is used to form a circulating flow through the core 21.

[0053] There are multiple discharge holes 31, six of which are used as an example here. The six discharge holes 31 are evenly spaced around the circumference of the matching tube 3, so that the hot coolant flowing out through the discharge holes 31 can flow evenly into the cylinder 22, thereby improving the uniformity of the distribution of the hot coolant.

[0054] In some optional other embodiments, the discharge hole 31 penetrates the matching tube 3 axially along the pressure container 2 .

[0055] With such arrangement, a part of the hot coolant discharged through the discharge hole 31 is mixed with the coolant flowing out through the core 21, and the other part flows upward in a direction away from the core 21. This increases the flow rate of the coolant discharged from the discharge hole 31 on the one hand, and also increases the density difference between the hot coolant in the cylinder 22 and the main coolant 5 in the annular space on the other hand, thereby promoting the upward circulation of the hot coolant.

[0056] In some other embodiments, the number of the discharge holes 31 is at least two, and at least one discharge hole 31 is opened on the inner side of the matching tube 3 away from the cylinder 22 .

[0057] That is, a portion of the discharge hole 31 is disposed at the top of the matching pipe 3, and a portion of the discharge hole 31 is disposed inside the matching pipe 3, so that the discharge flow rate of the hot coolant can be increased.

[0058] As for the matching pipe 3 , one end of the matching pipe 3 is welded to the connecting pipe 1 , and one end of the connecting pipe 1 is attached to the inner wall of the cylinder 22 .

[0059] The connecting pipe 1 is attached to the inner wall of the cylinder 22 , thereby reducing the space of the ascending flow channel of the ascending main coolant 4 occupied by the connecting pipe 1 .

[0060] The matching pipe 3 and the connecting pipe 1 may also be connected by snap connection or integrally arranged, which is not limited here.

[0061] In some other embodiments, the number of the connecting tubes 1 is at least two, and at least two connecting tubes 1 are evenly spaced around the circumference of the matching tube 3 .

[0062] The number of connecting pipes 1 can be adjusted according to actual needs. Here, one connecting pipe 1 is used as an example for explanation, but the number is not limited.

[0063] Regarding the matching tubes 3 , in some other embodiments, the number of the matching tubes 3 is at least two, and at least two matching tubes 3 are arranged at intervals along the length extension direction of the connecting tube 1 .

[0064] That is, a plurality of matching tubes 3 can be arranged side by side along the axial direction of the upper supporting tube group, so as to improve the uniformity of the outflow of the hot coolant in the upper supporting tube group.

[0065] The number of the matching tubes 3 and the number of the discharge holes 31 provided on each matching tube 3 are merely given as examples and are not specifically limited.

[0066] The startup heating principle of the present invention is as follows:

[0067] In the initial state, the coolant of the nuclear reactor is a certain T C When the heating is started, the heating device is started to inject a certain temperature T from the outside of the reactor vessel through the connecting pipe 1 into the cylinder 22 in the pressure vessel 2. H The hot coolant flows out from the discharge hole 31 opened on the matching pipe 3 of the starting heating device.

[0068] By continuously injecting hot coolant, the hot coolant is driven to flow upward, and the cold coolant is driven to flow along the top of the reactor pressure vessel 2 to the annular space, and after being cooled by the radiator 6, it passes downward through the annular space and enters the core 21 along the bottom of the reactor pressure vessel 2. At the same time, a part of the cold coolant is discharged from the outlet of the reactor vessel to balance the pressure value in the pressure vessel 2. The density difference between the rising main coolant 4 and the main coolant 5 in the annular space is used to form a circulating flow through the core 21.

[0069] In summary, the nuclear reactor startup heating device of the present invention adopts a connecting pipe 1 and a matching pipe 3 for cooperation, the first installation end 11 of the connecting pipe 1 is connected to the pressure vessel 2, and the matching pipe 3 is installed to the second installation end 12. By introducing hot coolant from the outside of the nuclear reactor and transporting it to the top of the core 21 through the connecting pipe 1 and the matching pipe 3, a density difference is caused between the main coolant in the riser and the coolant in the annular space, thereby driving the main coolant to circulate through the reactor core 21.

[0070] The core 21 is started quickly by using a mechanical structure to transport hot coolant, without the need to heat the coolant above the core 21 like a traditional heater, thus eliminating the external input device and control device of the traditional heater, and thus the sealing problem is easier to solve.

[0071] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "install", "connect", "connect", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0072] The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0073] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A nuclear reactor startup heating device, characterized in that: include: at least one connecting pipe, the connecting pipe having a first mounting end and a second mounting end, the first mounting end being connected to the pressure vessel, and the second mounting end extending into a cylinder disposed above the core; A matching pipe is connected to the second mounting end of the connecting pipe, and at least one discharge hole is provided on the matching pipe; wherein, When the nuclear reactor is started and heated, the hot coolant introduced from the outside of the nuclear reactor is transported to the matching pipe through the connecting pipe and flows out through the discharge hole to form a density difference between the rising main coolant in the cylinder and the main coolant in the annular space, thereby driving the main coolant to circulate through the core.

2. The nuclear reactor startup heating device according to claim 1, characterized in that: The matching tube is an annular tube, and one end of the matching tube is arranged close to the inner wall of the cylinder.

3. The nuclear reactor startup heating device according to claim 2, characterized in that: One end of the matching tube is connected to the inner wall of the cylinder.

4. The nuclear reactor startup heating device according to claim 2, characterized in that: At least two buckles are arranged at intervals on the outer circumference of the matching tube, and opposite ends of the buckles are respectively connected to the inner wall of the cylinder.

5. The nuclear reactor startup heating device according to claim 1, characterized in that: The first installation end of the connecting pipe is connected to a connecting pipe arranged on the pressure vessel.

6. The nuclear reactor startup heating device according to claim 1, characterized in that: At least two discharge holes are formed on a side of the matching tube away from the core, and the at least two discharge holes are spaced apart along the circumference of the matching tube.

7. The nuclear reactor startup heating device according to claim 1, characterized in that: The discharge hole penetrates the fitting tube in the axial direction of the pressure container.

8. The nuclear reactor startup heating device according to claim 1, characterized in that: The number of the discharge holes is at least two, and at least one of the discharge holes is opened on the inner side of the matching tube away from the cylinder.

9. The nuclear reactor startup heating device according to claim 1, characterized in that: One end of the matching pipe is welded to the connecting pipe, and one end of the connecting pipe is attached to the inner wall of the cylinder.

10. The nuclear reactor startup heating device according to claim 1, characterized in that: The number of the connecting tubes is at least two, and at least two connecting tubes are evenly spaced around the circumference of the matching tube.

11. The nuclear reactor startup heating device according to claim 1, characterized in that: The number of the matching tubes is at least two, and at least two matching tubes are arranged at intervals along the length extension direction of the connecting tube.

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