A cooling device for a primary loop sampling system of a nuclear power plant

Abstract

The present invention discloses a cooling device for a primary loop sampling system of a nuclear power plant, comprising: a cylinder assembly, comprising an inner cylinder and an outer cylinder, the inner cylinder being arranged inside the outer cylinder, the two ends of the inner cylinder being closed, the two ends of the outer cylinder being closed, a cooling medium channel being defined between the inner cylinder and the outer cylinder, the outer cylinder being provided with a cooling medium inlet and a cooling medium outlet connected to the cooling medium channel; a coil, formed into a spiral shape by a heat exchange tube coil, the coil being located in the cooling medium channel and coiled on the outside of the inner cylinder, and the two pipe openings of the coil being led out from the outer cylinder. The cylinder assembly adopts a double-layer cylinder structure of an inner cylinder and an outer cylinder, a cooling medium channel being defined between the inner cylinder and the outer cylinder, the flow of the cooling medium in the shell side is increased, and the heat exchange is enhanced. The tube side structure is simplified, and is specially configured as a spiral coil formed by a heat exchange tube coil, and there is no contact point in the device, which greatly reduces the risk of nuclear leakage.

Description

Technical Field

[0001] The invention is used in the field of nuclear power equipment, and in particular relates to a cooling device for a primary loop sampling system of a nuclear power plant. Background Art

[0002] In order to monitor the concentration of inhibitors and other chemical solvents in the primary coolant of a nuclear power plant in real time, it is necessary to sample the primary coolant of a nuclear power plant in operation. The fluid taken out has the characteristics of high pressure (15.5MPa), high temperature (343℃) and low flow rate (300L / h); and the fluid carries radioactive neutrons, so no trace leakage is allowed.

[0003] In order to carry out the analysis of the sampling fluid in a circuit, a cooling device needs to be set up to cool the fluid to room temperature using tap water. The cooling device in the prior art has the following disadvantages:

[0004] 1) Poor heat exchange performance and non-compact equipment structure;

[0005] 2) There are many interfaces on the pipe side, which may lead to nuclear leakage risks;

[0006] 3) The heat exchange tube is prone to vibration, causing local damage;

[0007] 4) The equipment has high thermal stress, short equipment life, and needs to be replaced frequently. Summary of the invention

[0008] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a cooling device for a primary loop sampling system of a nuclear power plant, which has a more compact structure, a stronger heat exchange capacity and a lower leakage risk.

[0009] The technical solution adopted by the present invention to solve its technical problem is:

[0010] A cooling device for a primary loop sampling system of a nuclear power plant, comprising:

[0011] A cylinder assembly, comprising an inner cylinder and an outer cylinder, wherein the inner cylinder is arranged inside the outer cylinder, both ends of the inner cylinder are closed, both ends of the outer cylinder are closed, a cooling medium channel is defined between the inner cylinder and the outer cylinder, and a cooling medium inlet and a cooling medium outlet connected to the cooling medium channel are provided on the outer cylinder;

[0012] The coil is made of a heat exchange tube coil in a spiral shape. The coil is located in the cooling medium channel and is coiled around the outside of the inner cylinder. Both pipe openings of the coil are led out from the outer cylinder.

[0013] In some embodiments, the inner cylinder and the outer cylinder both include:

[0014] Cylindrical barrel;

[0015] An upper head having an arc-shaped cross section, the upper head being connected to the upper end of the cylindrical body;

[0016] The lower end cap has an arc-shaped cross section and is connected to the lower end of the cylindrical body.

[0017] In some embodiments, the cooling medium inlet is located in the middle of the lower head of the outer cylinder, the cooling medium outlet is located in the middle of the upper head of the outer cylinder, and the two pipe openings of the coil include a sampling water inlet and a sampling water outlet, the sampling water inlet is led out from the top of the outer cylinder, and the sampling water inlet is led out from the bottom of the outer cylinder.

[0018] In some embodiments, a support cylinder is provided at the bottom of the inner cylinder at a position opposite to the cooling medium inlet, a first through hole is provided on the cylinder wall of the support cylinder, a pad is provided on the inner side of the lower head of the outer cylinder, and a lower positioning block cooperating with the support cylinder is provided on the pad.

[0019] In some embodiments, a limiting cylinder is provided on the top of the inner cylinder at a position opposite to the cooling medium outlet, a second through hole is provided on the limiting cylinder, and an upper positioning block cooperating with the limiting cylinder is provided on the inner side of the upper head of the outer cylinder.

[0020] In some embodiments, a heat insulating component is provided between the two pipe openings of the coil and the outer cylinder.

[0021] In some embodiments, the thermal insulation component includes a thermal sleeve, which is sleeved on the outside of the coil and has a gap between the coil, the outer wall of the thermal sleeve is connected to the outer cylinder, and one end of the thermal sleeve is shrunken and connected to the outer wall of the coil.

[0022] In some embodiments, it also includes:

[0023] A plurality of support plates are provided with a plurality of grooves cooperating with the coil along the length direction, the plurality of support plates are distributed along the circumference of the inner cylinder in the cooling medium channel, and the support plates are connected to the inner cylinder and / or the outer cylinder.

[0024] In some embodiments, an upper clamping joint is provided at the upper end of the support plate, a lower clamping joint is provided at the lower end of the support plate, an upper support block and a lower support block are provided on the inner wall of the outer cylinder, both the upper support block and the lower support block are provided with pits, the upper clamping joint is embedded in the pit of the upper support block, the lower clamping joint is embedded in the pit of the lower support block, and the groove of the support plate is installed between the inner cylinder and the outer cylinder toward the direction of the outer sleeve.

[0025] In some embodiments, a plurality of ear-type supports are provided on the outer side of the outer cylinder.

[0026] One of the above technical solutions has at least one of the following advantages or beneficial effects:

[0027] The cylinder assembly adopts a double-layer cylinder structure of an inner cylinder and an outer cylinder, and a cooling medium channel is defined between the inner cylinder and the outer cylinder, which increases the flow of the cooling medium in the shell side and strengthens the heat exchange.

[0028] The tube structure is simplified and is specially designed to be a spiral coil made of a heat exchange tube coil. There are no joints in the device, which greatly reduces the risk of nuclear leakage.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0031] Figure 1 It is a top view of the structure of an embodiment of the present invention;

[0032] Figure 2 yes Figure 1 Cross-section at AA;

[0033] Figure 3 yes Figure 1 The schematic diagram of the arrangement structure of the coil inside the cylinder assembly of one embodiment is shown;

[0034] Figure 4 yes Figure 1 A schematic diagram of a coil structure of an embodiment is shown;

[0035] Figure 5 yes Figure 1 A schematic diagram of the support plate structure of an embodiment is shown. DETAILED DESCRIPTION

[0036] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0037] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0038] In the present invention, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present invention, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0039] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0040] See also Figure 1 , Figure 2 , Figure 3 The embodiment of the present invention provides a cooling device for a nuclear power plant primary loop sampling system, which can be used for sampling the primary loop coolant of a nuclear power plant. The cooling device for a nuclear power plant primary loop sampling system includes a cylinder assembly 1 and a coil 2. The cylinder assembly 1 includes an inner cylinder 11 and an outer cylinder 12. The inner cylinder 11 is arranged inside the outer cylinder 12. Both ends of the inner cylinder 11 are closed, and both ends of the outer cylinder 12 are closed. A cooling medium channel 13 is defined between the inner cylinder 11 and the outer cylinder 12. A cooling medium inlet 14 and a cooling medium outlet 15 connected to the cooling medium channel 13 are provided on the outer cylinder 12. The cylinder assembly 1 forms a shell side, and the shell side serves as a pressure-bearing boundary of the cooling medium (for example, low-pressure cooling water at normal temperature). When in use, the cooling medium flows in from the cooling medium inlet 14 and flows out from the cooling medium outlet 15, during which heat exchange is performed with the coil 2 to reduce the temperature of the coolant in the coil 2. In order to carry out the analysis of the primary loop sampling fluid, the fluid is cooled to a normal temperature state.

[0041] See also Figure 2 , Figure 3 , Figure 4 The coil 2 is made of a heat exchange tube coil in a spiral shape. The coil 2 is located in the cooling medium channel 13 and is coiled on the outside of the inner cylinder 11. The two pipe openings of the coil 2 are both led out from the outer cylinder 12. The coil 2 forms a tube pass, which serves as the pressure-bearing boundary of the high-temperature and high-pressure sampling fluid. When in use, the high-temperature and high-pressure sampling fluid flows in from one of the pipe openings of the coil 2, exchanges heat with the cooling medium in the cooling medium channel 13 along the coil 2, and achieves temperature reduction and pressure reduction.

[0042] Among them, the cylinder assembly 1 adopts a double-layer cylinder structure of an inner cylinder 11 and an outer cylinder 12, and a cooling medium channel 13 is defined between the inner cylinder 11 and the outer cylinder 12, that is, the inner cylinder 11 is sleeved inside the outer cylinder 12, occupying part of the internal space of the outer cylinder 12, and forming an interlayer at the position where the coil 2 needs to be arranged. Due to the addition of the inner cylinder 11, the flow of the shell-side cooling medium at the coil 2 is greatly increased, and the heat exchange with the coil 2 is strengthened. The inner cylinder 11 provides a high-flow rate and high-disturbance flow channel for the cooling medium, increases the heat exchange capacity of the shell side, and makes the device structure more compact.

[0043] The embodiment of the present invention is specially configured to form a spiral coil 2 made of a heat exchange tube coil, which greatly increases the contact area with the cooling medium and strengthens the heat exchange. At the same time, there are no joints in the parts that contact the primary loop sampling fluid containing radiated neutrons, and there are no contacts in the device, which simplifies the tube structure and greatly reduces the risk of nuclear leakage.

[0044] The inner cylinder 11 and the outer cylinder 12 can be designed in different shapes, such as a polygonal cylinder, a circular cylinder, or an elliptical cylinder, etc. Figure 1 In some of the embodiments shown, the inner cylinder 11 and the outer cylinder 12 are designed in a contoured manner, that is, the inner cylinder 11 and the outer cylinder 12 both include a cylindrical cylinder, an upper head 16 and a lower head 17. The upper head 16 has an arc-shaped cross section, and the upper head 16 is connected to the upper end of the cylindrical cylinder by welding, threading, interference fit, etc. The lower head 17 has an arc-shaped cross section, and the lower head 17 is connected to the lower end of the cylindrical cylinder by welding, threading, interference fit, etc. Among them, the arc is the shape of a part of a circle or an ellipse. In this embodiment, by using a cylindrical cylinder with an arc-shaped upper head 16 and a lower head 17, the structure of the shell side is simpler and more compact, the force is more uniform, and the pressure resistance is better.

[0045] In some embodiments, see Figure 2 The cooling medium inlet 14 is located in the middle of the lower head 17 of the outer cylinder 12, and the cooling medium outlet 15 is located in the middle of the upper head 16 of the outer cylinder 12. The two pipe openings of the coil 2 include a sampling water inlet 21 and a sampling water outlet 22. The sampling water inlet 21 is drawn from the top of the outer cylinder 12, and the sampling water inlet 21 is drawn from the bottom of the outer cylinder 12. When in use, the cooling medium (such as room temperature tap water) is injected from the bottom of the shell side and then overflows from the top of the shell side. On the contrary, the sampling fluid is injected from the top of the tube side and then flows out from the bottom of the tube side. During this period, the large temperature difference between the cooling medium and the sampling fluid is utilized to fully exchange heat between the cooling medium and the sampling fluid, thereby improving the heat exchange efficiency.

[0046] The inner cylinder 11 is separated from the outer cylinder 12 by providing a support structure in the middle and / or at the bottom, and is positioned. Figure 2A support cylinder 18 is provided at the bottom of the inner cylinder 11 at a position opposite to the cooling medium inlet 14, and a pad 19 is provided on the inner side of the lower head 17 of the outer cylinder 12. The pad 19 is welded to the inner surface of the lower head 17, and the local thickness and strength of the lower head 17 are increased by the pad 19. A lower positioning block 110 cooperating with the support cylinder 18 is provided on the pad 19. The lower positioning blocks 110 are distributed circumferentially along the edge of the support cylinder 18. The lower positioning blocks 110 can be continuous or discontinuously distributed. The lower positioning block 110 is used to confine the support cylinder 18 inside. The pad 19 and the lower positioning block 110 are used to support and position the support cylinder 18, which is convenient for the installation of the inner cylinder 11 and reduces the vibration of the device during operation. Among them, because the support tube 18 covers the inner side of the cooling medium inlet 14, in order to allow the cooling medium to flow through, a first through hole 111 is provided on the tube wall of the support tube 18. One or more first through holes 111 are provided for the cooling medium introduced by the cooling medium inlet 14 to flow through.

[0047] For further information, see Figure 2 A limiting cylinder 112 is provided at the top of the inner cylinder 11 at a position opposite to the cooling medium outlet 15, and an upper positioning block 113 cooperating with the limiting cylinder 112 is provided on the inner side of the upper head 16 of the outer cylinder 12. The function of the upper positioning block 113 is to support and position the limiting cylinder 112, facilitate the installation of the inner cylinder 11, and reduce the vibration of the device during operation. Among them, a second through hole 114 is provided on the limiting cylinder 112 for the cooling medium to pass through and flow out from the cooling medium outlet 15. The positioning block limits the radial freedom of the inner cylinder 11, reduces the risk of flow-induced vibration of the inner cylinder 11, and avoids damage to the coil due to the instability of the inner cylinder 11, thereby improving the reliability of the inner cylinder 11.

[0048] In some embodiments, see Figure 1 , Figure 2 , Figure 3 The two pipe openings of the coil 2 have straight extension sections, that is, the top pipe opening of the coil 2 extends upward, and the bottom pipe opening of the coil 2 extends downward. The extension section of the coil 2 passes through the upper head 16 and the lower head 17 of the outer cylinder. Moreover, a heat insulation component is provided between the two pipe openings of the coil 2 and the outer cylinder 12. The heat insulation component can protect the upper head 16 and the lower head 17 from the high temperature impact of the sampling fluid and reduce the thermal stress of the upper head 16 and the lower head 17.

[0049] The heat insulation components can be heat insulation pads, heat insulation sleeves, heat insulation cavities and other heat insulation structures, for example, Figure 2 , Figure 3In some of the illustrated embodiments, the heat insulating component includes a heat sleeve 115, which is sleeved on the outside of the coil 2. The heat sleeve 115 and the coil 2 are coaxially or non-coaxially arranged, and a gap is left between the heat sleeve 115 and the coil 2 for heat insulation. The outer wall of the heat sleeve 115 is connected to the outer cylinder 12, and the diameter of one end of the heat sleeve 115 inside the outer shell is reduced and connected to the outer wall of the coil 2, that is, the heat sleeve 115 adopts a structure with one end closed and the other end open. On the one hand, the heat sleeve 115 is used as a connecting piece for the coil 2, and on the other hand, it can protect the upper head 16 and the lower head 17 from the high temperature impact of the sampling fluid, reduce the thermal stress of the upper head 16 and the lower head 17, and improve the life and reliability of the head.

[0050] In some embodiments, see Figure 2 , Figure 5 The cooling device also includes a plurality of support plates 3 for supporting the coil 2. The length direction of the support plate 3 is along the axial direction of the cylinder assembly 1. The support plate 3 is provided with a plurality of grooves 31 cooperating with the coil 2 along the length direction. The grooves 31 are distributed along the edge of the support plate 3. The support plate 3 is in a comb-tooth structure. The plurality of support plates 3 are distributed circumferentially along the inner cylinder 11 in the cooling medium channel 13. The support plate 3 is connected to the inner cylinder 11 and / or the outer cylinder 12. The coil 2 passes through each groove 31 of the support plate 3, reducing the risk of flow-induced vibration of the coil 2. However, the coil 2 is not completely fixed by the support plate 3. The coil 2 can expand freely, the support plate 3 can expand freely, the coil 2 can expand and deform along the winding direction of the coil 2, and is not restricted by the support plate 3. The coil 2 has no thermal stress, thereby improving the reliability of the coil 2.

[0051] The support plate 3 can be connected to the inner cylinder 11 and / or the outer cylinder 12 by welding, bolting, etc., for example Figure 2 , Figure 5In the embodiment shown, an upper clamping joint 32 is provided at the upper end of the support plate 3, and the upper clamping joint 32 extends to one side of the support plate 3. A lower clamping joint 33 is provided at the lower end of the support plate 3, and the lower clamping joint 33 extends to one side of the support plate 3. An upper support block 41 and a lower support block 42 are provided on the inner wall of the outer cylinder 12, and the upper support blocks 41 and the lower support blocks 42 are arranged opposite to each other along the axial direction of the cylinder. All the upper support blocks 41 are located on the same horizontal plane, and all the lower support blocks 42 are located on the same horizontal plane. A pit is provided on each of the upper support blocks 41 and the lower support blocks 42, and the upper clamping joint 32 is embedded in the pit of the upper support block 41, and the lower clamping joint 33 is embedded in the pit of the lower support block 42, so as to limit the circumferential position of the support plate 3 and prevent the support plate 3 from shaking. The groove 31 of the support plate 3 is installed between the inner cylinder 11 and the outer cylinder 12 toward the outer sleeve. The upper support block 41 and the lower support block 42 can support the weight of the spiral coil 2 and the support plate 3, limit the circumferential movement of the support plate 3, and allow the support plate 3 to expand freely in the axial direction of the spiral coil 2, thereby eliminating thermal stress and improving the life of components. The circumferential freedom of the support plate 3 is limited, and it can slide freely in the axial direction, thereby eliminating the axial thermal stress of the support plate 3. Among them, the plane side of the support plate 3 is close to the inner cylinder 11, and the comb side is close to the outer cylinder 12. The purpose of this arrangement is that the thermal expansion of the spiral coil 2 will not be restricted by the support plate 3, and the spiral tube can expand freely, thereby eliminating the thermal stress caused by the difference between the initial temperature and the operating temperature, thereby improving the service life of the device.

[0052] In some embodiments, see Figure 1 , Figure 2 A plurality of ear-type supports 5 are provided on the outer side of the outer cylinder 12, and the cooling device is fixedly mounted on a foundation or a stand through the ear-type supports 5.

[0053] In the description of this specification, the description with reference to the terms "example", "embodiment" or "some embodiments" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0054] Of course, the invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A cooling device for a primary loop sampling system of a nuclear power plant, characterized in that: include: A cylinder assembly, comprising an inner cylinder and an outer cylinder, wherein the inner cylinder is arranged inside the outer cylinder, both ends of the inner cylinder are closed, both ends of the outer cylinder are closed, a cooling medium channel is defined between the inner cylinder and the outer cylinder, and a cooling medium inlet and a cooling medium outlet connected to the cooling medium channel are provided on the outer cylinder; The coil is formed into a spiral shape by a heat exchange tube coil, the coil is located in the cooling medium channel and is coiled on the outside of the inner cylinder, and the two pipe openings of the coil are both led out of the outer cylinder; The inner cylinder and the outer cylinder both include: Cylindrical barrel; An upper end cap connected to the upper end of the cylindrical body; A lower end cap connected to the lower end of the cylindrical body; The cooling medium inlet is located in the middle of the lower head of the outer cylinder, the cooling medium outlet is located in the middle of the upper head of the outer cylinder, a limiting cylinder is provided on the top of the inner cylinder at a position opposite to the cooling medium outlet, a second through hole is provided on the limiting cylinder, and an upper positioning block cooperating with the limiting cylinder is provided on the inner side of the upper head of the outer cylinder.

2. The cooling device for the primary loop sampling system of a nuclear power plant according to claim 1, characterized in that: The cross section of the upper head is arc-shaped, and the cross section of the lower head is arc-shaped.

3. The cooling device for the primary loop sampling system of a nuclear power plant according to claim 2, characterized in that: The two pipe openings of the coil include a sampling water inlet and a sampling water outlet. The sampling water inlet is led out from the top of the outer cylinder, and the sampling water outlet is led out from the bottom of the outer cylinder.

4. The cooling device for the primary loop sampling system of a nuclear power plant according to claim 3, characterized in that: A support cylinder is provided at the bottom of the inner cylinder at a position opposite to the cooling medium inlet, a first through hole is provided on the cylinder wall of the support cylinder, a pad is provided on the inner side of the lower head of the outer cylinder, and a lower positioning block cooperating with the support cylinder is provided on the pad.

5. The cooling device for the primary loop sampling system of a nuclear power plant according to claim 1, characterized in that: A heat insulation component is provided between the two pipe openings of the coil and the outer cylinder.

6. The cooling device for the primary circuit sampling system of a nuclear power plant according to claim 5, characterized in that: The heat insulating component comprises a heat sleeve, which is sleeved outside the coil and has a gap between the heat sleeve and the coil. The outer wall of the heat sleeve is connected to the outer cylinder, and one end of the heat sleeve is shrunken and connected to the outer wall of the coil.

7. The cooling device for the primary loop sampling system of a nuclear power plant according to claim 1, characterized in that: Also includes: A plurality of support plates are provided with a plurality of grooves cooperating with the coil along the length direction, the plurality of support plates are distributed along the circumference of the inner cylinder in the cooling medium channel, and the support plates are connected to the inner cylinder and / or the outer cylinder.

8. The cooling device for the primary loop sampling system of a nuclear power plant according to claim 7, characterized in that: An upper clamping joint is provided at the upper end of the support plate, and a lower clamping joint is provided at the lower end of the support plate. An upper support block and a lower support block are provided on the inner wall of the outer cylinder. Both the upper support block and the lower support block are provided with pits. The upper clamping joint is embedded in the pit of the upper support block, and the lower clamping joint is embedded in the pit of the lower support block. The groove of the support plate is installed between the inner cylinder and the outer cylinder toward the direction of the outer sleeve.

9. The cooling device for the primary loop sampling system of a nuclear power plant according to claim 1, characterized in that: A plurality of ear-type supports are arranged on the outer side of the outer cylinder.

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