Passive cooling system

Abstract

The invention relates to the technical field of cooling systems, and provides a passive cooling system which comprises a heat exchange device, a first pipeline and a separation box, the heat exchange device is used for carrying out heat exchange with seawater, the heat exchange device is connected with the separation box, and the heated seawater enters the separation box; the first pipeline is connected with the separation box, and the first pipeline is used for discharging the heated seawater; a partition plate is arranged in the separation box and used for preventing steam bubbles from flowing along the first pipeline. According to the passive cooling system, by arranging the partition plate in the separation box, a steam-water mixture can be separated by utilizing buoyancy force and the partition plate, so that steam is gathered at the top of the separation box, and liquid is gathered at the bottom of the separation box, so that the liquid is discharged from the first pipeline, and the steam in the first pipeline is prevented from being directly contacted with backflow supercooled seawater to cause condensation; and a water hammer is further induced.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling systems, and in particular to a passive cooling system. Background Art

[0002] In an offshore floating platform, the core of the power system will continue to generate heat after the reactor is shut down. The heat accumulated in the core will increase the temperature of the internal components of the core, and the core fuel rod cladding may melt, resulting in leakage of radioactive materials, threatening the safety of personnel and equipment. In order to solve the core safety problem after the reactor is shut down, the offshore floating platform is equipped with a passive cooling system connected to the hot hydrazine seawater. During the operation of the passive cooling system, the system relies on the driving force generated by the density difference between the cold and hot fluids in the cold and hot pipes to realize the circulation of the coolant, thereby safely exporting the core residual heat to the final hot hydrazine seawater. However, when the core residual heat power is large, the fluid in the hot pipe section of the passive cooling system undergoes a drastic phase change, and a large amount of steam exists in the heat pipe connected to the seawater, thereby forming a steam plug. When the steam plug in the hot pipe section is in direct contact with the refluxed supercooled seawater, the steam condenses rapidly, and the steam plug collapses, causing water hammer in the heat pipe, resulting in large pressure pulsations and flow oscillations, thereby affecting the structural integrity of the passive cooling system and reducing the system's heat transfer capacity, threatening the safety of the offshore floating platform.

[0003] There are currently two technical solutions to alleviate the water hammer phenomenon caused by steam condensation in heat pipes of passive systems. One is to add a knob-type tie device inside the pipe, which produces a turbulent effect by the knob to prevent the generation of large steam bombs to eliminate the water hammer; the other is to install a perforated plate compartment at the outlet of the heat pipe to eliminate the water hammer by suppressing the return of seawater to the heat pipe. However, the above two technical solutions add additional condensation water hammer elimination devices inside the heat pipe or at the outlet of the heat pipe. The additional devices will increase the flow resistance of the system loop, reduce the heat transfer capacity of the passive cooling system, and thus threaten the safety of the offshore floating platform. Summary of the invention

[0004] The present invention provides a passive cooling system, which is used to solve the defect in the prior art that the flow resistance of the system loop is increased due to the addition of a condensate hammer elimination device.

[0005] The present invention provides a passive cooling system, comprising: a heat exchange device, a first pipeline and a separation box; the heat exchange device is used to exchange heat with seawater, the heat exchange device is connected to the separation box, and the heated seawater enters the separation box; the first pipeline is connected to the separation box, and the first pipeline is used to discharge the heated seawater; a partition is arranged in the separation box, and the partition is used to block steam bubbles from flowing along the first pipeline.

[0006] According to a passive cooling system provided by the present invention, the separation box is provided with a liquid inlet and a liquid outlet, the liquid inlet is connected to the heat exchange device, and the liquid outlet is connected to the first pipeline; the liquid inlet and the liquid outlet are located on both sides of the partition.

[0007] According to a passive cooling system provided by the present invention, the height of the partition is greater than the height of the liquid outlet.

[0008] A passive cooling system provided according to the present invention further includes a second pipeline, the separation box is provided with a steam outlet, and the steam outlet is located above the liquid outlet; the second pipeline is connected to the steam outlet, and the second pipeline is used to discharge steam.

[0009] A passive cooling system provided according to the present invention further includes a first valve, which is arranged in the first pipeline.

[0010] A passive cooling system provided according to the present invention further includes a second valve, wherein the second valve is arranged in the second pipeline.

[0011] A passive cooling system provided according to the present invention further includes a liquid level meter, and the liquid level meter is arranged in the separation box.

[0012] A passive cooling system provided according to the present invention further includes a controller, wherein the controller is used to control the opening and closing of the second valve according to the liquid level data detected by the liquid level meter.

[0013] According to a passive cooling system provided by the present invention, the heat exchange device includes: a heat exchanger and a third pipeline, the third pipeline is thermally coupled to the heat exchanger; the first end of the third pipeline is used to introduce seawater, and the second end of the third pipeline is connected to the separation box.

[0014] A passive cooling system provided according to the present invention further includes a third valve, and the third valve is arranged in the third pipeline.

[0015] The passive cooling system provided by the present invention can separate the steam-water mixture by using buoyancy and the baffles by arranging baffles in the separation box, so that the steam gathers at the top of the separation box and the liquid gathers at the bottom of the separation box, thereby discharging the liquid from the first pipeline, thereby avoiding direct contact and condensation of the steam in the first pipeline with the refluxed supercooled seawater, thereby inducing water hammer; the passive cooling system provided by the present invention does not require additional structural parts, the flow resistance of the system is not significantly increased, and the heat transfer capacity is guaranteed while eliminating water hammer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or 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 It is a structural schematic diagram of the passive cooling system provided by the present invention.

[0018] Reference numerals: 10. Heat exchanger; 11. Heat exchange tube; 12. Third pipeline; 13. Third valve; 20. Separation box; 21. Partition; 30. First pipeline; 31. First valve; 40. Second pipeline; 41. Second valve; 50. Liquid level meter. DETAILED DESCRIPTION

[0019] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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 an indirect connection through an intermediate medium. 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 embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0023] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0024] Combine the following Figure 1 The passive cooling system of the present invention is described.

[0025] like Figure 1 As shown, in an embodiment of the present invention, the passive cooling system includes: a heat exchange device, a separation box 20 and a first pipeline 30. The heat exchange device is connected to the separation box 20, and the heat exchange device is used to exchange heat with seawater. The first pipeline 30 is connected to the separation box 20, and the first pipeline 30 is used to discharge the heated seawater. A partition 21 is provided in the separation box 20, and the partition 21 is used to prevent steam bubbles from flowing along the first pipeline 30.

[0026] Specifically, under the heating action of the heat exchange device, the temperature of the fluid in the heat exchange device gradually increases, the density gradually decreases, and a density difference is generated between the fluid and the seawater. Under the action of the driving force generated by the density difference, the seawater enters the heat exchange device, and the seawater is heated by the heat exchange device. The heated seawater enters the separation box 20, and then flows through the first pipeline 30 into the ocean.

[0027] When the heat exchange amount in the heat exchange device exceeds a certain value, the seawater is heated to boil, generating a large number of bubbles, and forming a steam-water mixture containing a large number of steam bubbles. When the steam-water mixture enters the separation box 20, the steam bubbles gather at the top of the separation box 20 under the action of buoyancy to form a steam space, and the liquid phase fluid gathers at the bottom of the separation box 20 to form a liquid phase space, and there is an obvious phase interface between the steam and the liquid. The steam bubbles rise under the action of buoyancy, and are blocked by the partition 21 during the rising process, so that the steam bubbles gather at the top of the separation box 20 and do not enter the first pipeline 30, and the liquid is discharged from the first pipeline 30.

[0028] In this embodiment, by providing a partition 21, the steam-water mixture in the separation box 20 can be separated, and only saturated water is discharged into the ocean through the first pipeline 30, thereby fundamentally avoiding water hammer induced by direct contact and condensation between steam in the first pipeline 30 and the returning supercooled seawater.

[0029] The passive cooling system provided by the embodiment of the present invention can separate the steam-water mixture by using buoyancy and the baffles by arranging baffles in the separation box, so that the steam gathers at the top of the separation box and the liquid gathers at the bottom of the separation box, thereby discharging the liquid from the first pipeline, thereby avoiding direct contact and condensation of the steam in the first pipeline with the refluxed supercooled seawater, thereby inducing water hammer; the passive cooling system provided by the embodiment of the present invention does not require additional structural parts, the flow resistance of the system is not significantly increased, and the heat transfer capacity is guaranteed while eliminating water hammer.

[0030] In an embodiment of the present invention, the separation box 20 is provided with a liquid inlet and a liquid outlet, the liquid inlet is connected to the heat exchange device, and the liquid outlet is connected to the first pipeline 30 , and the liquid inlet and the liquid outlet are located on both sides of the partition 21 .

[0031] Specifically, under the heating action of the heat exchange device, the temperature of the fluid in the heat exchange device gradually increases, the density gradually decreases, and a density difference is generated between the fluid and the seawater. Under the action of the driving force generated by the density difference, the seawater enters the heat exchange device, and the seawater is heated by the heat exchange device. The heated seawater enters the separation box 20 from the liquid inlet.

[0032] When the heat exchange amount in the heat exchange device exceeds a certain value, the seawater is heated to boil, generating a large number of bubbles, and forming a steam-water mixture containing a large number of steam bubbles. After the steam-water mixture enters the separation box 20, the steam bubbles rise under the action of buoyancy. During the rising process of the steam bubbles, the partition 21 blocks the steam bubbles, thereby preventing the steam bubbles from flowing into the first pipeline 30 from the liquid outlet during the rising process, thereby avoiding the condensation of the steam bubbles in the first pipeline 30 to cause water hammer.

[0033] Furthermore, in an embodiment of the present invention, the height of the partition 21 is greater than the height of the liquid outlet, so that the steam bubbles can move upward along the partition 21 under the action of buoyancy, thereby forming a steam space at the top of the separation box 20, and the liquid can pass over the partition 21 and enter the first pipeline 30 from the liquid outlet, thereby discharging the heated seawater into the ocean.

[0034] like Figure 1 As shown, in an embodiment of the present invention, the passive cooling system further includes a second pipeline 40, the separation box 20 is provided with a steam outlet, the steam outlet is located above the liquid outlet, the second pipeline 40 is connected to the steam outlet, and the second pipeline 40 is used to discharge steam.

[0035] Specifically, as the passive cooling system operates, more and more steam gathers on the top of the separation box 20, and the liquid level in the separation box 20 gradually decreases. When the liquid level is lower than the height of the partition 21, the liquid cannot be discharged from the first pipeline 30. Therefore, before the liquid level in the separation box 20 drops below the partition 21, the second pipeline 40 should be opened in time to discharge the steam in the separation box 20 through the second pipeline 40, so that the liquid level in the separation box 20 rises.

[0036] In the above-described embodiment, the liquid inlet may be arranged on the bottom surface of the separation box 20 to facilitate the seawater to enter the separation box 20 under the action of the driving force; the liquid outlet may be arranged on the side of the separation box 20, and the steam outlet may be arranged on the top surface of the separation box 20 to facilitate the discharge of steam.

[0037] like Figure 1 As shown, in an embodiment of the present invention, the heat exchange device includes: a heat exchanger 10 and a third pipeline 12, the third pipeline 12 is thermally coupled to the heat exchanger 10, the first end of the third pipeline 12 is used to introduce seawater, and the second end of the third pipeline 12 is connected to the separation box 20.

[0038] Specifically, the heat exchanger 10 includes a heat exchange tube 11. Under the heating effect of the heat exchanger 10, the temperature of the fluid in the heat exchange tube 11 gradually increases, and the density gradually decreases. A density difference is formed between the fluid in the heat exchange tube 11 and the seawater. The density difference generates a driving force, which prompts the seawater to enter the third pipeline 12. The seawater exchanges heat with the high-temperature fluid in the heat exchange tube 11, and the seawater is heated. The heated seawater enters the separation box 20.

[0039] like Figure 1 As shown, in an embodiment of the present invention, the passive cooling system further includes a first valve 31, a second valve 41 and a third valve 13, wherein the first valve 31 is disposed in the first pipeline 30, and is used to control the on-off of the first pipeline 30. The second valve 41 is disposed in the second pipeline 40, and is used to control the on-off of the second pipeline 40. The third valve 13 is disposed in the third pipeline 12, and is used to control the on-off of the third pipeline 12.

[0040] Specifically, before the passive cooling system is put into use, the first valve 31, the second valve 41 and the third valve 13 are all in a closed state, and the first pipeline 30 and the third pipeline 12 are isolated from the seawater. After the passive cooling system is put into use, the first valve 31 and the third valve 13 are opened, and the seawater enters the third pipeline 12 under the driving force generated by the density difference between the fluid and the seawater. The seawater exchanges heat with the high-temperature fluid in the heat exchange tube 11, and the seawater is heated, and the heated seawater enters the separation box 20.

[0041] When the heat exchange amount in the heat exchanger 10 exceeds a certain value, the seawater is heated to boil, generating a large number of bubbles, and forming a steam-water mixture containing a large number of steam bubbles. When the steam-water mixture enters the separation box 20, the steam bubbles gather at the top of the separation box 20 under the action of buoyancy to form a steam space, and the liquid phase fluid gathers at the bottom of the separation box 20 to form a liquid phase space, and there is an obvious phase interface between the steam and the liquid. In this process, the second valve 41 is closed, the steam bubbles gather at the top of the separation box 20, and the first valve 31 is in an open state, and the liquid is discharged from the first pipeline 30 to the ocean.

[0042] As more and more steam gathers on the top of the separation box 20, the liquid level in the separation box 20 gradually decreases. Before the liquid level in the separation box 20 drops below the partition 21, the second valve 41 is opened to discharge the steam in the separation box 20 through the second pipeline 40 to increase the liquid level in the separation box 20.

[0043] like Figure 1 As shown, in the embodiment of the present invention, the passive cooling system further includes a liquid level meter 50 , which is disposed in the separation box 20 and is used to detect the liquid level of the liquid in the separation box 20 .

[0044] Furthermore, the passive cooling system further includes a controller, which is electrically connected to the liquid level meter 50 and the second valve 41 .

[0045] Specifically, the liquid level meter 50 is used to detect the liquid level of the liquid in the separation box 20 in real time. When the liquid level reaches the first preset value, that is, when the liquid level is about to be flush with the top of the partition 21, the liquid level meter 50 sends a signal to the controller, and the controller controls the second valve 41 to open to discharge the steam. When the liquid level returns to the second preset value, the controller controls the second valve 41 to close. In this embodiment, the first preset value is a lower liquid level, and the second preset value is a higher liquid level.

[0046] It can be understood that: according to the specific heights of the separation box 20 and the partition 21, the first preset value and the second preset value can be flexibly set so that the controller can automatically control the second valve 41 to be opened or closed.

[0047] 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 passive cooling system, characterized in that: It includes: a heat exchange device, a first pipeline and a separation box; The heat exchange device is used to exchange heat with seawater, the heat exchange device is connected to the separation box, and the heated seawater enters the separation box; The first pipeline is connected to the separation box, and the first pipeline is used to discharge the heated seawater; A partition is arranged in the separation box, and the partition is used to block the steam bubbles from flowing along the first pipeline.

2. The passive cooling system according to claim 1, characterized in that: The separation box is provided with a liquid inlet and a liquid outlet, the liquid inlet is communicated with the heat exchange device, and the liquid outlet is communicated with the first pipeline; The liquid inlet and the liquid outlet are located on both sides of the partition.

3. The passive cooling system according to claim 2, characterized in that: The height of the partition is greater than the height of the liquid outlet.

4. The passive cooling system according to claim 2, characterized in that: It also includes a second pipeline, the separation box is provided with a steam outlet, and the steam outlet is located above the liquid outlet; The second pipeline is connected to the steam outlet, and the second pipeline is used to discharge steam.

5. The passive cooling system according to claim 1, characterized in that: The device also includes a first valve, which is disposed in the first pipeline.

6. The passive cooling system according to claim 4, characterized in that: The device also includes a second valve, which is arranged in the second pipeline.

7. The passive cooling system according to claim 6, characterized in that: It also includes a liquid level meter, which is arranged on the separation box.

8. The passive cooling system according to claim 7, characterized in that: It also includes a controller, which is used to control the opening and closing of the second valve according to the liquid level data detected by the liquid level meter.

9. The passive cooling system according to claim 1, characterized in that: The heat exchange device comprises: a heat exchanger and a third pipeline, wherein the third pipeline is thermally coupled to the heat exchanger; The first end of the third pipeline is used for introducing seawater, and the second end of the third pipeline is communicated with the separation box.

10. The passive cooling system according to claim 9, characterized in that: It also includes a third valve, which is arranged in the third pipeline.

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