Cold package with enhanced heat dissipation capability, reactor-based cold neutron source and reactor

Abstract

The invention discloses a cold package with enhanced heat dissipation capability, a reactor-based cold neutron source and a reactor, and belongs to the technical field of nuclear. The cold bag capable of enhancing the heat dissipation capacity comprises a moderator input pipe, a moderator output pipe, a cold bag cavity and a coolant circulation loop. Wherein the moderator input pipe comprises an inflow section and a bent backflow section, the cold package cavity is connected with the backflow section and arranged on one side of the inflow section, and the maximum cross section of the cold package cavity covers the orientation interval of neutron conduit arrangement; the coolant circulating pipeline comprises an input interlayer, an output interlayer and a coolant cavity, the coolant cavity wraps the cold package cavity, the backflow section and part of the inflow section, and the space between the cold package cavity and the inflow section is located in the coolant cavity. The cold package provides a coolant with a larger volume for the moderator for heat dissipation, and the heat dissipation capacity and the cold neutron output efficiency of the cold package in the neutron moderation process can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nuclear technology, and particularly relates to a cold package with enhanced heat dissipation capacity, a reactor-based cold neutron source, and a reactor. BACKGROUND

[0002] The reactor-based cold neutron source is the most mature and reliable neutron source scheme at present, and is one of the important foundations for realizing technologies such as neutron scattering. The performance of the reactor-based cold neutron source depends largely on the structural design of the neutron source cold package. The existing reactor-based cold neutron source cold packages generally adopt a nested thin-walled special-shaped structure, which is complex in structure, and a considerable part of the moderator in the cold package does not actually contribute to the neutron output, but still generates nuclear heating. Moreover, the nested cold package structure has insufficient cooling potential, resulting in a lack of optimization space for the neutron output capacity of the reactor-based cold neutron source. Therefore, providing a cold package with enhanced heat dissipation capacity has a positive significance for optimizing the efficiency and reliability of the reactor-based cold neutron source. SUMMARY

[0003] The present application aims to provide a cold package with enhanced heat dissipation capacity, which optimizes the efficiency and reliability of the reactor-based cold neutron source. The present application also provides a reactor-based cold neutron source and a reactor.

[0004] According to an embodiment of one aspect of the present application, a cold package with enhanced heat dissipation capacity is provided, which is arranged in a reactor and comprises a moderator input pipe, a moderator output pipe, a cold package cavity, and a coolant circulation pipeline, the cold package cavity being connected between the moderator input pipe and the moderator output pipe, wherein the moderator input pipe comprises an inflow section and a reflux section, the inflow section being arranged in parallel with the moderator output pipe, and the reflux section being arranged in a bent manner relative to the inflow section; the cold package cavity is connected to the reflux section, the cold package cavity being arranged on one side of the inflow section, and the maximum cross section of the cold package cavity covering the azimuthal interval in which the neutron guide tube is arranged; the coolant circulation pipeline comprises an input interlayer, an output interlayer, and a coolant cavity; the coolant cavity covers the cold package cavity, the reflux section, and part of the inflow section, so that the space between the cold package cavity and the inflow section is in the coolant cavity; the input interlayer is wrapped around the part of the moderator input pipe located outside the coolant cavity; and the output interlayer is wrapped around the part of the moderator output pipe located outside the coolant cavity.

[0005] The cold package cavity of the cold package is arranged at one side of the inflow section of the moderator input pipe, and is arranged in a non-nested manner, so that the total amount of the moderator reacting with thermal neutrons in the cold package is reduced, and the heat generation is reduced; the coolant cavity covers the cold package cavity, the coolant completely fills the gap between the cold package cavity and the inflow section, the volume ratio of the coolant is increased under the condition that the volume occupied by the cold package in the vacuum cylinder is unchanged, and the heat dissipation capacity of the cold package is further enhanced, which creates conditions for further improving the cold neutron output capacity of the reactor-based cold neutron source.

[0006] Further, in some embodiments, the shape of the largest cross section of the cold package cavity is a sector around the inflow section.

[0007] Further, in some embodiments, the cold package cavity further comprises a lower head connected to the return section and an upper head connected to the moderator output pipe, and the upper head and the lower head are in a variable cross-section structure.

[0008] Further, in some embodiments, the upper head protrudes towards the inflow section.

[0009] Further, in some embodiments, the coolant circulation pipeline further comprises a coolant cavity sleeve in communication with the input interlayer and extending to the bottom of the coolant cavity, and the end of the coolant cavity sleeve at the bottom of the coolant cavity is provided with a sleeve opening, which is the inlet of the coolant in the coolant cavity.

[0010] Further, in some embodiments, the coolant cavity sleeve surrounds the part of the inflow section in the coolant cavity.

[0011] Further, in some embodiments, the cross section of the input interlayer and the inflow section is a concentric circle structure, and the cross section of the output interlayer and the moderator output pipe is a concentric circle structure.

[0012] According to an embodiment of another aspect of the present application, a reactor-based cold neutron source is provided, and the cold package of the reactor-based cold neutron source adopts the cold package with enhanced heat dissipation capacity provided in any of the foregoing embodiments.

[0013] Further, in some embodiments, the reactor-based cold neutron source adopts liquid hydrogen or deuterium as the moderator, and adopts low-temperature helium gas as the coolant.

[0014] According to an embodiment of another aspect of the present application, a reactor is provided, and the reactor is provided with a reactor-based cold neutron source, which is the reactor-based cold neutron source adopting the cold package with enhanced heat dissipation capacity provided in any of the foregoing embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1A schematic view of a cold pack structure for enhancing heat dissipation capacity in an embodiment; Figure 2 A schematic view of a cross-sectional structure of a cold pack for enhancing heat dissipation capacity in an embodiment; Figure 3 A schematic view of a cold pack structure for an alternative embodiment; Figure 4 A schematic view of a cross-sectional structure of a cold pack for an alternative embodiment.

[0016] Meaning of reference signs: 1 - moderator input pipe; 11 - inflow section; 12 - return flow section; 2 - cold pack cavity; 21 - lower head; 22 - middle section; 23 - upper head; 24 - special-shaped cold pack clamping cavity; 3 - moderator output pipe; 4 - input cladding layer; 5 - coolant cavity; 51 - coolant cavity sleeve; 52 - sleeve opening; 6 - output cladding layer; 7 - special-shaped coolant cavity; 71 - communication hole; 72 - inner layer of special-shaped coolant cavity; 73 - outer layer of special-shaped coolant cavity.

[0017] The above drawings are intended to provide a detailed description of the present application for the purpose of enabling those skilled in the art to understand the technical concept of the present application, and are not intended to limit the present application. For the purpose of brevity, the above drawings only schematically show the structures related to the technical features of the present application, and do not strictly show the complete structures and all details according to the actual proportions. DETAILED DESCRIPTION

[0018] The present application will be further described in detail through specific embodiments in combination with the drawings.

[0019] Reference herein to "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment herein. The phrase appears at various places in the specification is not necessarily referring to the same embodiment, nor is it limited to mutually exclusive or alternative embodiments. Those skilled in the art should understand that the embodiments herein can be combined with other embodiments without structural conflicts.

[0020] In the description herein, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connecting" and the like should be understood broadly, for example, can be movable connection, or fixed connection or integral. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present application according to the specific circumstances.

[0021] In the description herein, the terms "upper", "lower", "left", "right", "lateral", "longitudinal", "height", "length", "width" and the like indicating the orientation or positional relationship are intended to accurately describe the embodiments and simplify the description, and are not intended to limit the parts or structures involved to have a specific orientation, be installed or operated in a specific orientation, and cannot be understood as a limitation on the embodiments herein.

[0022] In the description herein, the terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the number, specific order or primary and secondary relationship of the technical features described. In the description herein, the meaning of "a plurality of" is at least two.

[0023] Neutron scattering technology is widely used in the fields of military industry, energy, semiconductor and new materials, and the demand is higher and higher with the development of technology. The basis of neutron scattering technology is a cold neutron source, and the reactor-based cold neutron source is the most stable and reliable cold neutron source scheme at present. The basic principle of the reactor-based cold neutron source is to establish a region containing an ultralow-temperature neutron moderator in the high thermal neutron flux region of the reactor, to slow down the thermal neutrons by the ultralow-temperature neutron moderator until the cold neutrons reach thermal equilibrium with the ultralow-temperature moderator, and then to transport the cold neutrons to the outside of the reactor through a neutron transport system such as a neutron conduit. Among them, the main component containing the ultralow-temperature moderator and reacting with the thermal neutrons is the cold package of the cold neutron source, and the structure of the cold package has a key influence on the performance and efficiency of the cold neutron source.

[0024] At present, the typical structure of the reactor-based cold neutron source cold package is as shown in Figure 3 and Figure 4 , which includes a moderator input pipe 1, a cold package cavity 2, a moderator output pipe 3, an input interlayer 4, an output interlayer 6 and a special-shaped coolant cavity 7. The moderator flows into the cold package cavity 2 from the moderator input pipe 1, and the cold package cavity 2 is the main area for the moderator to slow down the thermal neutrons. The main body is a special-shaped cold package cavity 24 with a ring-shaped cross section, and the space inside and outside the special-shaped cold package cavity is connected to form a special-shaped coolant cavity 7. After the moderator is slowed down by the thermal neutrons in the cold package cavity 2, it flows out to the heat exchanger (not shown) of the cold neutron source through the moderator output pipe 3, is cooled by the heat exchanger, and then flows back through the moderator input pipe 1, realizing a thermosyphon circulation. Since energy exchange occurs during the process of the moderator slowing down the thermal neutrons, the deposited nuclear heating in the moderator is heated and warmed up, so the coolant is needed to cool the moderator. The coolant flows into the inner layer 72 of the special-shaped coolant cavity through the input interlayer 4, the bottom of the special-shaped cold package cavity 24 is provided with a communication hole 71, the coolant flows out to the outer layer 73 of the special-shaped coolant cavity through the communication hole 71, and finally flows out through the output interlayer 6. In this cold package structure, the inner and outer surfaces of the special-shaped cold package cavity 24 can be fully cooled by the coolant, so that the deposited nuclear heating can be effectively dissipated, and the interlayer can also form a protective boundary to prevent the moderator from leaking.

[0025] However, if Figure 4 As shown, the special-shaped cold pack sandwich cavity 24 is a multi-layer nested structure, and its overall structure is very complex and difficult to manufacture. At the same time, the cross-section of the special-shaped cold pack sandwich cavity 24 is annular. Due to structural limitations, the distribution range of the neutron lead-out tube cannot cover the entire annular surface, which results in a considerable portion of the cold neutrons obtained by moderator slowing down in the special-shaped cold pack sandwich cavity 24 cannot be utilized, but the nuclear heating still needs to be cooled by coolant, which increases the heat dissipation pressure. Furthermore, the complex structure of the special-shaped cold pack sandwich cavity 24 also limits the design optimization of the coolant pipeline, and it is difficult to improve the overall heat dissipation capacity of the cold pack by increasing the coolant.

[0026] In order to overcome the above-mentioned problems of the prior art, the present invention provides a cold pack with enhanced heat dissipation capacity in an embodiment of the present invention, which can increase the volume proportion of the coolant in the cold pack and improve the heat dissipation capacity of the cold pack.

[0027] The neutron source cold pack structure is as follows Figure 1 and Figure 2 As shown, it includes a moderator input pipe 1, a moderator output pipe 3, a cold package cavity 2 and a coolant circulation pipeline.

[0028] The moderator inlet pipe 1 includes an inflow section 11 and a return section 12. The inflow section 11 is arranged parallel to the moderator outlet pipe 3, while the return section 12 is bent in a U-shape relative to the inflow section 11. A cold pack cavity 2 is connected to the return section 12 and is located on one side of the inflow section 11. Its cross-sectional area is larger than that of the moderator inlet pipe 1 and the moderator outlet pipe 3, forming an expanded structure. The maximum cross-sectional area of ​​the cold pack cavity 2 can cover the azimuth range of the neutron guide arrangement.

[0029] The coolant circulation circuit includes an input interlayer 4, an output interlayer 6, and a coolant cavity 5. The coolant cavity 5 encloses the cold pack cavity 2, the return section 12, and a portion of the inflow section 11, ensuring that the space between the cold pack cavity 2 and the inflow section is within the coolant cavity 5. The input interlayer 4 surrounds the portion of the moderator input pipe 1 outside the coolant cavity 5, while the output interlayer 6 surrounds the moderator output pipe. In a preferred embodiment, the input interlayer 4 forms a concentric circle with the cross section of the moderator input pipe 1, and the output interlayer 6 also forms a concentric circle with the cross section of the moderator output pipe 3.

[0030] In a preferred embodiment, the cold ladle cavity 2 has a middle section 22, which is the portion with the largest cross-sectional area. Its cross-sectional shape is a sector-shaped surface arranged around the inflow section 11. The cold ladle cavity 2 also includes an upper head 23 disposed at the top and a lower head 21 disposed at the bottom. The upper and lower heads 23, 21 have gradually varying cross-sectional areas, with the upper head 23 protruding toward the inflow section 11.

[0031] In a further preferred embodiment, the coolant circulation pipeline of the cold pack further includes a coolant cavity sleeve 51, which is disposed within the coolant cavity 5. The upper end of the coolant cavity sleeve 51 is connected to the inlet section 11, and the lower end extends to the bottom of the coolant cavity 5 and is provided with a sleeve opening 52. The sleeve opening 52 serves as the inlet for the coolant within the coolant cavity 5. The coolant flows from the sleeve opening 52 into the bottom of the coolant cavity 5, enters the output interlayer from the top of the coolant cavity 5, and flows back to the radiator. Thermal convection is used to promote sufficient flow of the coolant within the coolant cavity to avoid the formation of dead zones.

[0032] In this cold pack structure, the cross-sectional shape of the cold pack cavity 2 is fan-shaped instead of the annular shape used in the prior art. This simplifies the structure while ensuring a more consistent distribution of the moderator involved in moderating thermal neutrons and the spatial distribution of the neutron guides. This reduces the volume of the moderator while improving its utilization efficiency. By reducing the amount of ineffectively heat-generating moderator, the cold pack's heat dissipation capacity is further optimized. Furthermore, the coolant cavity 5 increases the volume ratio of the coolant in the cold pack, resulting in a stronger heat dissipation capacity for the same amount of nuclear heat accumulated in the moderator.

[0033] According to another embodiment of the present invention, a reactor-based cold neutron source is provided, comprising a vacuum cylinder, a neutron conduit, a heat exchanger, and a cold pack. The cold pack and heat exchanger are placed within the vacuum cylinder, wherein the cold pack employs the enhanced heat dissipation cold pack provided in any of the aforementioned embodiments. The reactor-based cold neutron source utilizes liquid hydrogen or deuterium as a moderator and cryogenic helium as a coolant. A circulation pipeline is established between the heat exchanger and the cold pack, allowing coolant to flow from outside the reactor into the cooling device for heat exchange before flowing out of the reactor. The moderator exiting the cold pack undergoes sufficient heat exchange with the coolant within the cooling device, then cools and flows back to the cold pack, thereby maintaining a stable low-temperature state. Thermal neutrons are cooled by the moderator in the cold pack to become cold neutrons, which are then collected by the neutron conduit and output outside the reactor for use in various neutron experiments utilizing the cold neutron source, such as neutron diffraction.

[0034] An embodiment of another aspect of the present invention provides a reactor, in which one or more reactor-based cold neutron sources are provided. The reactor-based cold neutron sources are the reactor-based cold neutron sources provided in any of the aforementioned embodiments.

[0035] The purpose of the above embodiments is to provide a further detailed description of the present invention in conjunction with the accompanying drawings so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the present invention, optimization or equivalent replacement of the technical features involved, as well as combination of implementation methods in different embodiments without conflict of structure and principle, all fall within the scope of protection of the present invention.

Claims

1. A cold pack for enhancing heat dissipation capacity, arranged in a reactor, comprising a moderator input pipe, a moderator output pipe, a cold pack cavity, and a coolant circulation pipeline, wherein the cold pack cavity is connected between the moderator input pipe and the moderator output pipe, and is characterized in that: The moderator input pipe includes an inflow section and a reflux section, wherein the inflow section is arranged in parallel with the moderator output pipe, and the reflux section is arranged in a curved manner relative to the inflow section; The cold bag cavity is connected to the return section, and the cold bag cavity is arranged on one side of the inflow section. The maximum cross section of the cold bag cavity covers the azimuth interval where the neutron guide tube is arranged; The coolant circulation pipeline includes an input interlayer, an output interlayer and a coolant cavity; the coolant cavity covers the cold pack cavity, the reflux section and part of the inflow section, so that the space between the cold pack cavity and the inflow section is within the coolant cavity; the input interlayer surrounds the portion of the moderator input pipe located outside the coolant cavity; the output interlayer surrounds the portion of the moderator output pipe located outside the coolant cavity.

2. The cold pack with enhanced heat dissipation capacity according to claim 1, characterized in that: The maximum cross-section of the cold bag cavity is in the shape of a sector surface arranged around the inflow section.

3. The cold pack with enhanced heat dissipation capacity according to claim 1 or 2, characterized in that: The cold package cavity further includes a lower head and an upper head, the lower head is connected to the reflux section, the upper head is connected to the moderator output pipe, and the upper head and the lower head form a variable cross-section structure.

4. The cold pack with enhanced heat dissipation capability according to claim 3, characterized in that: The upper head protrudes toward the inflow section.

5. The cold pack with enhanced heat dissipation capability according to claim 1 or 2, characterized in that: The coolant circulation pipeline also includes a coolant cavity sleeve, which is connected to the input interlayer and extends to the bottom of the coolant cavity. The coolant cavity sleeve is provided with a sleeve opening at the end of the bottom of the coolant cavity, and the sleeve opening is the inlet of the coolant in the coolant cavity.

6. The cold pack with enhanced heat dissipation capability according to claim 5, characterized in that: The coolant cavity sleeve surrounds a portion of the inflow section within the coolant cavity.

7. The cold pack with enhanced heat dissipation capability according to claim 1 or 2, characterized in that: The cross section of the input interlayer and the inflow section is a concentric circle structure; the cross section of the output interlayer and the moderator output pipe is a concentric circle structure.

8. A reactor-based cold neutron source, comprising a cold pack, characterized in that: The cold pack is a cold pack with enhanced heat dissipation capability as claimed in any one of claims 1 to 7.

9. The reactor-based cold neutron source according to claim 8, characterized in that: Liquid hydrogen or deuterium is used as a moderator, and low-temperature helium is used as a coolant.

10. A reactor comprising a reactor-based cold neutron source, characterized in that: The reactor-based cold neutron source adopts the reactor-based cold neutron source as claimed in claim 8 or 9.

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