Heat pipe stack waste heat removal system

Abstract

The embodiment of the present invention relates to the technical field of deep-sea nuclear power systems, and provides a heat pipe stack waste heat removal system. The heat pipe stack waste heat removal system includes a heat pipe stack and a heat exchanger, wherein the heat pipes of the heat pipe stack are in a horizontal lying state, the heat exchanger includes an outer shell, the heat pipes are inserted through the outer shell, the outer shell includes an inner shell and an outer shell, and the upper and lower relative positions of the outer shell are respectively provided with a water outlet and a water inlet, and the water outlet and the water inlet connect the inside of the inner shell with the outside of the outer shell. The heat pipe stack waste heat removal system provided by the embodiment of the present invention realizes the passive discharge of the waste heat of the heat pipe stack, and compared with the traditional reactor waste heat removal system, it omits a special cooler, simplifies the system structure, reduces the system volume, saves precious cabin space, and can be suitable for underwater vehicles with extremely narrow internal space.

Description

Technical Field

[0001] The present invention relates to the technical field of deep-sea nuclear power systems, and in particular to a heat pipe pile waste heat removal system. Background Art

[0002] Unmanned undersea vehicle (UUV) is an effective tool for deep-sea scientific investigation, resource survey and development, and underwater specific task execution. In order to meet the requirements of output power and endurance when it develops in the direction of large-scale, long-range, high-speed and intelligent, it often uses nuclear power devices with high energy density, long life, and air independence as the power source. Due to the precious cabin space resources, complex underwater environment and unmanned conditions in the deep sea, advanced reactors must be used.

[0003] At present, a lot of research has been conducted on heat pipe reactors both at home and abroad, covering the ocean, land and space. The heat pipe reactor (abbreviated as: heat pipe reactor) is a fully solid-state core that uses heat pipes as a means of extracting heat from the core. There is no loop system or rotating parts. The system is greatly simplified, and the core can be maintenance-free, which is particularly suitable for UUVs with limited space. After the reactor fails and stops, the fission products decay and the remaining neutrons continue to react, bringing special residual heat (abbreviated as residual heat). If it is not taken away in time, it will cause reactor fusion and leakage of radioactive materials and other serious consequences. Therefore, fully ensuring nuclear safety is the first condition for the application of reactors.

[0004] In response to this problem, a passive residual heat removal system has been developed in the design of land-based nuclear power plants. That is, when the reactor is shut down due to a fault, the residual heat can be removed by natural circulation without human intervention. The passive residual heat removal technology has become an important safety guarantee for the application of nuclear energy. At present, the research on the use of nuclear reactors in UUVs is not in-depth enough, and there are no reports on the passive residual heat removal system of nuclear reactors applied to UUVs. The passive residual heat removal system of land-based nuclear power plants usually requires a very high vertical space to arrange the cooler to enhance the driving force of natural circulation and ensure that enough cooling medium can remove the heat. Therefore, it is not suitable for the extremely narrow space in the UUV. Summary of the invention

[0005] The embodiment of the present invention provides a heat pipe stack waste heat removal system, which is used to solve the problem that the existing passive waste heat removal system has a large structural size and is not suitable for underwater vehicles with limited space.

[0006] An embodiment of the present invention provides a heat pipe stack waste heat removal system, comprising a heat pipe stack and a heat exchanger, wherein the heat pipes of the heat pipe stack are in a horizontal lying state, the heat exchanger comprises an outer shell, the heat pipes are inserted through the outer shell, the outer shell comprises an inner shell and an outer shell, a water outlet and a water inlet are respectively arranged at upper and lower relative positions of the outer shell, and the water outlet and the water inlet connect the interior of the inner shell with the exterior of the outer shell.

[0007] The interior of the inner shell is provided with a plurality of vertical partitions along the axial direction of the heat pipe, and the plurality of vertical partitions divide the interior of the inner shell into a plurality of cooling channels, and the cooling channels are connected with the water outlet and the water inlet.

[0008] Wherein, a plurality of heat pipes are nested in the same vertical partition.

[0009] Among them, transverse baffles are respectively installed at the upper end and the lower end of each of the vertical baffles, and gaps are left between two adjacent transverse baffles and between the transverse baffle at the edge and the inner shell. The cooling channel is connected with the water outlet and the water inlet through the gap. The multiple transverse baffles located on the same side of the multiple vertical baffles form an arc surface with the gap, and a water collection area is formed between the arc surface and the inner shell.

[0010] Wherein, water collecting bodies protruding outward are constructed at upper and lower relative positions of the inner shell body, and the water collecting area is formed between the water collecting body and the arc surface.

[0011] Wherein, the width of the gap gradually decreases from the middle to both sides.

[0012] Wherein, the water inlet is equipped with a stop valve, and the water outlet is equipped with a check valve.

[0013] Wherein, the outer shell is a cylindrical structure, and the heat pipe is parallel to the axis of the cylindrical structure.

[0014] Wherein, the heat exchanger is installed on the insulation section of the heat pipe.

[0015] The heat pipe stack waste heat removal system provided in the embodiment of the present invention is provided with a heat exchanger on a horizontally lying heat pipe, and a water inlet and a water outlet are provided on the heat exchanger shell, so that seawater can automatically enter the heat exchanger to exchange heat with the heat pipe, thereby realizing that the waste heat of the reactor can be automatically removed by seawater without human intervention, that is, passive waste heat removal; in addition, by providing a double-shell heat exchanger, it is ensured that the heat pipes in the heat exchanger do not exchange heat with the outside when the heat pipe stack is operating normally, thereby reducing the loss of heat energy. Compared with the traditional reactor waste heat removal system, the heat pipe stack waste heat removal system eliminates the need for a special cooler, simplifies the structure of the passive waste heat removal system, reduces the volume, saves precious cabin space, and can be applied to underwater vehicles with extremely narrow internal space. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is a schematic structural diagram of a heat pipe stack waste heat removal system according to an embodiment of the present invention;

[0018] Figure 2 It is an AA cross-sectional view of a heat pipe stack waste heat removal system according to an embodiment of the present invention.

[0019] In the figure: 1. heat pipe stack; 11. heat pipe; 2. heat exchanger; 21. inner shell; 22. outer shell; 23. water outlet; 24. water inlet; 3. vertical partition; 4. cooling channel; 51. first transverse baffle; 52. second transverse baffle; 53. third transverse baffle; 61. first gap; 62. second gap; 63. third gap. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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, 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.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "first" and "second" are for the purpose of clearly describing the numbering of product components and do not represent any substantial difference. The directions of "up", "down", "left" and "right" are all based on the directions shown in the accompanying drawings. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1 The figure shows a schematic structural diagram of a heat pipe stack waste heat removal system according to an embodiment of the present invention, wherein the heat pipe stack waste heat removal system comprises a heat pipe stack 1 and a heat exchanger 2, wherein the heat pipes 11 of the heat pipe stack 1 are in a horizontal lying state, the heat exchanger 2 comprises an outer shell, the heat pipes 11 are inserted through the outer shell, the outer shell comprises an inner shell 21 and an outer shell 22, and a water outlet 23 and a water inlet 24 are respectively provided at upper and lower relative positions of the outer shell, wherein the water outlet 23 and the water inlet 24 connect the interior of the inner shell 21 with the exterior of the outer shell 22.

[0024] Specifically, Figure 1 As shown, through holes matching the heat pipe 11 are provided at both ends of the heat exchanger 2 so that the heat exchanger 2 can be sleeved on the heat pipe 11. When the heat pipe stack 1 is operating normally, the water outlet 23 and the water inlet 24 are in a closed state, the internal space of the shell is in a sealed state, and under the protection of the double-layer shell, the heat pipe 11 in the heat exchanger 2 does not exchange heat with the outside world. At this time, this section of the heat pipe belongs to the insulation section of the heat pipe 11; when the heat pipe stack 1 is stopped, the water inlet 24 and the water outlet 23 are opened, and seawater automatically enters the inner shell 21 from the water inlet 24 and exchanges heat with the heat pipe 11, cooling the outer wall of the heat pipe 11, and the temperature of the seawater itself increases and the density decreases, so that it continues to flow upward and flows out through the water outlet 23 to discharge the residual heat in the heat pipe stack 1.

[0025] The heat pipe stack waste heat removal system provided in the embodiment of the present invention is provided with a heat exchanger 2 on a horizontally lying heat pipe 11, and a water inlet 24 and a water outlet 23 are provided on the shell of the heat exchanger 2, so that seawater can automatically enter the heat exchanger 2 to exchange heat with the heat pipe 11, thereby realizing that the waste heat of the reactor can be automatically removed by seawater without human intervention, that is, passive waste heat removal; in addition, by providing a double-shell heat exchanger 2, it is ensured that the heat pipe 11 in the heat exchanger 2 does not exchange heat with the outside when the heat pipe stack 1 is operating normally, thereby reducing the loss of heat energy. Compared with the traditional reactor waste heat removal system, the heat pipe stack waste heat removal system eliminates the need for a special cooler, simplifies the structure of the passive waste heat removal system, reduces the volume, and can be applied to underwater vehicles with extremely narrow internal space, especially unmanned submersibles, saving precious cabin space.

[0026] It should be noted that the heat pipe 11 is divided into an evaporation section, an insulation section and a condensation section. The evaporation section is located in the core body. The heat generated by the fission of the nuclear core of the reactor is transported from the evaporation section to the condensation section through the capillary force of the heat pipe 11, and is heat exchanged with the condensation section by the cooling medium for subsequent power generation system to do work. In order to reduce heat energy loss, the outside of the insulation section between the evaporation section and the condensation section is generally coated with an insulation layer to avoid heat exchange with the outside. The heat pipe stack waste heat removal system provided in the embodiment of the present invention can make full use of the space of the insulation section of the heat pipe 11, that is, the heat exchanger 2 is arranged in the insulation section of the heat pipe 11, and the cabin space occupied by the waste heat removal system is minimized.

[0027] The water inlet 24 is provided with a stop valve, and the water outlet 23 is provided with a check valve. In the embodiment of the present invention, the stop valve and the check valve are both electromagnetic control valves. The stop valve and the check valve are both in a normally closed state under normal power-on conditions. Under the accident shutdown condition, the nuclear power system stops generating electricity, the electromagnetic control valve loses power, and automatically opens at this time.

[0028] like Figure 2 The figure shows an AA cross-sectional view of a heat pipe stack waste heat removal system according to an embodiment of the present invention. A plurality of vertical partitions 3 are provided inside the inner shell 21 along the axial direction of the heat pipe 11. The plurality of vertical partitions 3 divide the interior of the inner shell 21 into a plurality of cooling channels 4. The cooling channels 4 are connected to the water outlet 23 and the water inlet 24.

[0029] Due to the problem of uneven radial power distribution in the heat pipe stack 1, the temperature of the heat pipes 11 on the heat pipe stack 1 is high in the middle and low around. In the embodiment of the present invention, by arranging a plurality of vertical baffles 3 in the inner shell 21, the seawater enters the inner shell 21 from the water inlet 24 and flows upward along the cooling channel 4, so that the seawater around the heat pipes 11 with higher middle temperatures can rise quickly, thereby accelerating the heat exchange of the middle high-temperature heat pipes 11.

[0030] In the embodiment of the present invention, multiple heat pipes 11 can be distributed in each cooling channel 4; multiple heat pipes 11 can also be nested on the same vertical partition 3, so that the heat pipes 11 on the same vertical partition 3 are in two cooling channels 4 at the same time, so that the heat of the middle high-temperature heat pipe 11 can be transferred to the low-temperature heat pipes 11 on both sides through seawater, thereby laterally uniformizing the temperature of each heat pipe 11, achieving uniform cooling of the heat pipe 11, and improving the waste heat discharge efficiency of the heat pipe stack 1.

[0031] by Figure 2 Take the distribution of the heat pipes 11 shown as an example, that is, the heat pipes 11 are distributed in a hexagonal array, and five rows of heat pipes 11 are distributed vertically. In the embodiment of the present invention, four vertical partitions can be set to form five cooling channels 4 in the inner shell 21, and the five rows of heat pipes 11 from left to right are located in these five cooling channels 4 one by one (not shown in the figure); five vertical partitions can also be set to form six cooling channels 4 in the inner shell 21, and the five rows of heat pipes 11 from left to right are embedded in these five vertical partitions one by one, so that each row of heat pipes 11 is in two adjacent cooling channels 4 at the same time, and the heat in adjacent cooling channels 4 can be transferred to each other through the heat pipes 11. Specifically, the number of heat pipes 11 in the most central row is the largest, and the overall temperature is the highest, so that the seawater temperature in the two middle cooling channels 4 is increased the fastest. On the one hand, as the seawater is rapidly heated up, the seawater in the two middle cooling channels 4 can be accelerated to rise, and the heat exchange can be accelerated; on the other hand, the heat of the middle heat pipe 11 can be transferred horizontally to the seawater in the cooling channels 4 on both sides through the two adjacent rows of heat pipes 11, thereby achieving uniform cooling.

[0032] In the embodiment of the present invention, transverse baffles are respectively installed at the upper and lower ends of each vertical partition 3, and gaps are left between two adjacent transverse baffles and between the outermost transverse baffle and the inner shell 21. The cooling channel 4 is connected with the water outlet 23 and the water inlet 24 through the gap. The multiple transverse baffles located on the same side of the multiple vertical partitions 3 form an arc surface with the gap, and a water collection area is formed between the arc surface and the inner shell 21.

[0033] Specifically, Figure 2 Taking the distribution of the vertical partitions 3 in FIG. 1 as an example, the five vertical partitions 3 are respectively the first vertical partition, the second vertical partition, the third vertical partition, the fourth vertical partition and the fifth vertical partition from left to right. The upper end and the lower end of the third vertical partition are respectively installed with the first transverse baffle 51, the upper end and the lower end of the second and fourth vertical partitions are respectively installed with the second transverse baffle 52, and the upper end and the lower end of the first and fifth vertical partitions are respectively installed with the third transverse baffle 53. Among them, the transverse baffle and the vertical partition 3 can be an integrally formed structure, or can be connected by other methods such as welding.

[0034] In the embodiment of the present invention, a first gap 61 is left between the first transverse baffle 51 and the second transverse baffle 52, a second gap 62 is left between the second transverse baffle 52 and the third transverse baffle 53, and a third gap 63 is left between the third transverse baffle 53 and the inner wall of the inner shell 21. The first transverse baffle 51, the second transverse baffle 52 and the third transverse baffle 53 located at the lower side of the five vertical baffles 3 form a first arc surface having the first gap 61, the second gap 62 and the third gap 63, and a lower water collection area is formed between the first arc surface and the inner shell 21; the first transverse baffle 51, the second transverse baffle 52 and the third transverse baffle 53 located at the upper side of the five vertical baffles 3 form a second arc surface having the first gap 61, the second gap 62 and the third gap 63, and an upper water collection area is formed between the second arc surface and the inner shell 21. It should be noted that in the embodiment of the present invention, the surface formed by the multiple horizontal baffles on the same side of the vertical partition 3 is not limited to an arc-shaped surface, and can also be arranged to adapt to the shape and structure of the actual inner shell 21, and the embodiment of the present invention does not make specific limitations.

[0035] The heat pipe stack waste heat removal system provided in the embodiment of the present invention does not require a special header, and uses the space between the inner shell of the heat exchanger 2 and the vertical partition 3 to distribute and mix seawater, thereby greatly saving the internal space of the underwater vehicle.

[0036] Seawater enters the lower water collection area from the water inlet 24, then flows into each cooling channel 4 from the first gap 61, the second gap 62 and the third gap 63 on the lower side of the five vertical partitions 3 to exchange heat with the heat pipe 11, and enters the upper water collection area from the first gap 61, the second gap 62 and the third gap 63 on the upper side of the five vertical partitions 3 respectively, and then is discharged from the heat exchanger 2 from the water outlet 23 after mixing.

[0037] In the embodiment of the present invention, the width of the gap gradually decreases from the middle to both sides. Figure 2 Taking the heat exchanger 2 structure in as an example, the widths of the first gap 61, the second gap 62 and the third gap 63 are gradually reduced. The seawater entering the lower water collection area is distributed through the first gap 61, the second gap 62 and the third gap 63. Since the first gap 61 is the largest, the seawater flow through the corresponding cooling channel 4 is also the largest, and the third gap 63 is the smallest, and the seawater flow through the corresponding cooling channel 4 is the smallest, so that the large flow of seawater flowing through the middle cooling channel 4 can take away more heat from the middle high-temperature heat pipe 11, and the low flow of seawater flowing through the cooling channels 4 on both sides can take away the heat of the relatively low-temperature heat pipes 11 on both sides. Thereby further achieving the purpose of uniform cooling.

[0038] The embodiment of the present invention ensures that the heat pipes 11 in the middle area with more heat pipes 11 have a larger flow of cooling water by coordinating the water collection area with gaps of different widths, while in the more marginal areas, the number of heat pipes 11 is small and a smaller amount of cooling water is used, thereby fully ensuring that each heat pipe 11 has an appropriate amount of cooling water, performing uniform cooling, and effectively removing the waste heat of the reactor.

[0039] like Figure 2 As shown, in the embodiment of the present invention, water collecting bodies protruding outward are constructed at the upper and lower relative positions of the inner shell body 21, and a water collecting area is formed between the water collecting body and the arc surface.

[0040] Specifically, still Figure 2 Taking the heat exchanger 2 structure in the example, the upper and lower relative positions of the inner shell 21, i.e., in the gravity direction, are respectively provided with an upper water collecting body and a lower water collecting body, a lower water collecting area is formed between the lower water collecting body and the first arc surface, and an upper water collecting area is formed between the upper water collecting body and the second arc surface. In this way, the internal space of the inner shell 21 can be expanded, the length of the cooling channel 4 can be as long as possible, and the contact area between the seawater and the heat pipe 11 can be increased.

[0041] It should be noted that the inner shell 21 and / or the outer shell 22 of the heat exchanger 2 in the embodiment of the present invention can be a cylindrical structure or a structure of other shapes. The embodiment of the present invention does not specifically limit it. As long as it can ensure that all the heat pipes 11 on the heat pipe stack 1 are inserted into the outer shell of the heat exchanger 2 and are located in the inner shell 21, the outer shell 22 can be designed according to the cabin space of the underwater vehicle, as long as a certain thickness of air insulation layer is formed between the inner shell 21 and the outer shell 22. When the outer shell 22 is a cylindrical structure, the axis of the heat pipe 11 is parallel to that of the outer shell 22. Among them, the inner shell 21 can also be adapted to the structure of the outer shell 22 designed as a cylindrical structure.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat pipe stack waste heat removal system, applied to an underwater vehicle, comprising a heat pipe stack, It is characterized in that It also includes a heat exchanger, the heat pipes of the heat pipe stack are in a horizontal lying state, the heat exchanger includes an outer shell, the heat pipes are inserted through the outer shell, the outer shell includes an inner shell and an outer shell, and the outer shell is provided with a water outlet and a water inlet at upper and lower relative positions, respectively, the water outlet and the water inlet connect the inside of the inner shell with the outside of the outer shell, and the multiple heat pipes are distributed in a hexagonal array.

2. The heat pipe stack waste heat removal system according to claim 1, It is characterized in that A plurality of vertical partitions are arranged inside the inner shell along the axial direction of the heat pipe, and the plurality of vertical partitions divide the interior of the inner shell into a plurality of cooling channels, and the cooling channels are connected with the water outlet and the water inlet.

3. The heat pipe stack waste heat removal system according to claim 2, It is characterized in that A plurality of heat pipes are nested in the same vertical partition.

4. The heat pipe stack waste heat removal system according to claim 2 or 3, It is characterized in that A transverse baffle is installed at the upper end and the lower end of each vertical baffle, and a gap is left between two adjacent transverse baffles and between the transverse baffle at the edge and the inner shell. The cooling channel is connected with the water outlet and the water inlet through the gap. The multiple transverse baffles located on the same side of the multiple vertical baffles form an arc surface with the gap, and a water collection area is formed between the arc surface and the inner shell.

5. The heat pipe stack waste heat removal system according to claim 4, It is characterized in that The inner shell body is provided with water collecting bodies protruding outward at the upper and lower relative positions, and the water collecting area is formed between the water collecting body and the arc surface.

6. The heat pipe stack waste heat removal system according to claim 4, It is characterized in that The width of the gap gradually decreases from the middle to both sides.

7. The heat pipe stack waste heat removal system according to claim 1, It is characterized in that The water inlet is equipped with a stop valve, and the water outlet is equipped with a check valve.

8. The heat pipe stack waste heat removal system according to claim 1, It is characterized in that The outer shell is a cylindrical structure, and the heat pipe is parallel to the axis of the cylindrical structure.

9. The heat pipe stack waste heat removal system according to claim 1, It is characterized in that The heat exchanger is installed on the insulation section of the heat pipe.

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