A recirculation cooling device and a recirculation method

Abstract

This invention relates to the field of cooling pool circulation, and discloses a circulating cooling device and circulation method, including a circulation module comprising a cooling pool and a heat exchange pool, and a heat exchange zone. The medium in the cooling pool undergoes heat exchange and is then transferred back to the cooling pool. A through-hole unit is provided between the cooling pool and the heat exchange pool to facilitate the transport of medium at different depths within the cooling pool, generating only minor turbulence at the surface and bottom. The medium is then transported to a heat exchanger via a conveying pipe, while simultaneously, cooling medium from the cooling tank is input into the heat exchanger to achieve heat exchange between the two. Finally, the cooled medium is discharged into the heat exchange pool. When the water level in the cooling pool remains normal, sufficient water can be stored in the heat exchange pool for cooling, and then output to the heat exchange pool via the heat exchanger for future use. This process does not require the injection of medium from the cooling tank, significantly reducing costs.

Description

Technical Field

[0001] This invention relates to the field of cooling pool circulation, and in particular to a circulating cooling device and circulation method. Background Technology

[0002] In nuclear power plants, the heat absorbed by equipment in the water cooling system needs to be effectively released to ensure continuous water circulation and maintain cooling effectiveness. However, under conventional conditions, natural heat dissipation has low heat exchange efficiency, releasing relatively little heat. This leads to increased energy loss in the water circulation system, affecting the overall operating efficiency of the nuclear power plant. Equipment placed in the water exhibits varying heat dissipation efficiencies due to differences in its structure and location, thus impacting the efficiency of water replacement. These differences may stem from factors such as the contact area between the equipment and water, water flow velocity, and water temperature.

[0003] Nuclear power plants typically use cooling pools to cool and seal nuclear products. When the cooling water temperature rise is insufficient to achieve the required temperature for recirculation in the cooling tower, the cooling water in the pool is allowed to cool naturally. This process takes longer and can wear down the equipment. Furthermore, cooling pools are not entirely clean; they contain floating leaves and non-biodegradable waste. Due to their large surface area, airborne debris and surrounding waste can fall into the pool, potentially causing problems during subsequent water pumping or clogging of the cooling equipment. Manually removing floating debris from the pool is extremely difficult and impractical. Industry regulations require that cooling water from nuclear power plant cooling pools be legally and compliantly approved before discharge. Simply discharging dust and impurities is not permitted, as it makes it impossible to maintain constant cleanliness of the cooling water. Therefore, cleaning the cooling pools is a challenging issue. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is that the water in the cooling pool cannot be recycled quickly, and there are many impurities in the cooling pool that are difficult to clean. The cooling pool will be blocked during the conventional water circulation process, and the water pumping efficiency is slow, which affects the cooling rate. In addition, the conventional natural cooling method is slow and may bring unpredictable risks to the equipment.

[0005] The above-mentioned technical problems are solved by the following technical solution: The present invention proposes a circulating cooling device, which includes a circulating module, including a cooling pool and a heat exchange pool, and a heat exchange zone, which transfers the medium in the cooling pool back to the cooling pool after heat exchange. A through-hole unit is provided between the cooling pool and the heat exchange pool, and the through-hole unit is used to transport the medium at different depths in the cooling pool.

[0006] In a preferred embodiment of the circulating cooling device of the present invention: the through-hole unit includes a surface medium conveying hole and a middle medium conveying hole, a safety line is provided in the cooling pool to ensure that the medium to be cooled in the cooling pool is always covered, the bottom of the middle medium conveying hole is horizontally arranged with the safety line, and a closing unit is provided at the middle medium conveying hole.

[0007] In a preferred embodiment of the circulating cooling device of the present invention: the surface medium conveying hole is disposed above the middle medium conveying hole.

[0008] In a preferred embodiment of the circulating cooling device of the present invention: the circulating module further includes a transport tank, which receives the medium after heat exchange output from the heat exchange zone, and the transport tank transports the medium into the cooling tank.

[0009] In a preferred embodiment of the circulating cooling device of the present invention: it further includes several sets of conveying pipes, which connect the cooling pool, the heat exchange pool, the heat exchange zone, and the conveying pool for medium transport; the conveying pipes output power through a pump, and a filter screen is provided at the end of the conveying pipes.

[0010] In a preferred embodiment of the circulating cooling device of the present invention: it further includes a cooling tank, which stores a cooling medium, and a heat exchanger is provided in the heat exchange zone. The input end of the heat exchanger receives the medium in the heat exchange tank through a delivery pipe, and the cooling tank is injected into the input end of the heat exchanger through a pipe that passes through the heat exchange zone.

[0011] In a preferred embodiment of the circulating cooling device of the present invention: the sidewall of the heat exchange zone is provided with a hole, and an exhaust fan is provided at the hole.

[0012] To solve the above-mentioned technical problems, the present invention also provides the following technical solution: a circulation method, comprising, wherein a cooling pool, a heat exchange pool, and a transport pool can all store a medium, and when the heat exchange pool does not store a medium, its internal impurities can be cleaned.

[0013] In a preferred embodiment of the circulation method of the present invention: the cooling pool needs to be cleaned of surface impurities. A medium is injected into the cooling pool through the transport pool. The surface medium in the cooling pool is discharged into the heat exchange pool through the surface medium transport hole. Then, the bottom medium in the cooling pool is extracted through the transport pipe and transported to the heat exchanger for heat exchange. Finally, it is transported to the transport pool for storage. Then, the impurities in the heat exchange pool are cleaned.

[0014] In a preferred embodiment of the circulation method of the present invention: when the medium in the cooling pool needs to exchange heat, the medium in the corresponding area of ​​the closed unit is taken out by opening the closed unit, thereby reducing the floating impurities and sediment impurities in the cooling pool, and the extraction pump is started to transport the medium to the heat exchanger through the delivery pipe for heat exchange and then discharge it to the tank to be transported. Then the medium in the tank to be transported is transported back to the cooling pool.

[0015] The beneficial effects of the circulation method of the present invention are as follows: rapid heat exchange is achieved through medium circulation between the cooling pool, the heat exchange tank, and the transport tank. When the temperature of the medium in the cooling pool rises and needs to be cooled down quickly, the closed unit on the middle layer medium transport hole is opened to take the middle layer medium from the cooling pool, thereby avoiding floating objects and sediments in the cooling pool. The heat exchange tank is filled with medium by quickly taking water. Due to the liquid level difference, the liquid level in the heat exchange tank can rise rapidly, and only a small amount of turbulence is generated on the water surface and bottom. At this time, the medium is transported to the heat exchanger through the transport pipe. At the same time, the cooling medium in the cooling tank is input into the heat exchanger to achieve heat exchange between the two. Finally, the cooled medium is discharged into the transport tank. When the water level in the cooling pool is kept normal, sufficient water can be stored in the heat exchange tank for cooling. After cooling, it is output to the transport tank through the heat exchanger for the next use. This process does not require the injection of medium into the cooling tank, which can greatly reduce costs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A schematic diagram of the overall structure of the circulating cooling device is shown; Figure 2 An overall side view of the circulating cooling unit is shown; Figure 3 A top view of the circulating cooling unit is shown; Figure 4 A side view sectional view of the circulating cooling device is shown; Figure 5 A top cross-sectional view of the circulating cooling unit is shown; Figure 6 A schematic diagram of the medium exchange between the cooling pool and the heat exchange pool in the circulating cooling device is shown. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0018] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0019] Reference Figures 1-6 This embodiment provides a circulating cooling device, including a circulating module 1, which includes a cooling pool 11 and a heat exchange pool 12, both existing cooling pools used to cool nuclear reactors and other equipment. A heat exchange zone 2 is a separate chamber used to house heat exchange equipment. In this design, a plate heat exchanger 21 is used, directly placed in the cooling pool 11. Because a large amount of mist and other gases are released during heat exchange, and excessively high temperatures pose a safety hazard, a separate heat exchange zone 2 is provided for isolation. A pipe runs through the chamber and connects to the heat exchanger 21. The two ends of the heat exchanger 21 are used for water intake and drainage, respectively, to transfer the medium in the cooling pool 11 back into the cooling pool 11 after heat exchange. Note that in this design… The medium refers to other cooling media such as coolant or cooling water. Further details on the medium will not be provided later. A through-hole unit 13 is provided between the cooling pool 11 and the heat exchange pool 12. The through-hole unit 13 is used to transport media at different depths within the cooling pool 11. Since conventional heat exchange usually uses pipelines for transport, even though conventional pipelines have connecting flanges and filters or filter elements at the flanges or pipe ends, impurities within the cooling pool 11 still pose a risk of clogging the pipelines. Therefore, by setting up the through-hole unit 13 to transport cooling media at different depths, it is possible to avoid cooling media containing impurities and select a cleaner medium for exchange, thereby greatly reducing the risk of pipeline blockage.

[0020] Meanwhile, if you choose to clean the floating or sediment in the cooling pool 11, you can choose the corresponding medium for transportation. Note that floating and sediment are usually common impurities, so you can treat these two types of impurities, but not only these two types of impurities.

[0021] Furthermore, the through-hole unit 13 includes a surface medium conveying hole 131 and a middle medium conveying hole 132. In this scheme, since some impurities may remain at the bottom of the heat exchange pool 12, these impurities may be stirred up during medium exchange from the bottom, thus affecting the subsequent pumping effect. Therefore, this scheme does not set a bottom conveying hole. A safety line is set in the cooling pool 11 to ensure that the medium to be cooled in the cooling pool 11 is always covered. The actual safety line is to ensure that the nuclear reactor and other equipment to be cooled are always covered by the cooling medium. When the liquid level drops below the safety line, it is necessary to monitor it at all times and take emergency measures. The bottom of the middle medium conveying hole 132 is set horizontally with the safety line, and a closing unit 133 is set at the middle medium conveying hole 132. The closing unit 133 is used to form the opening, closing and sealing process of the middle medium conveying hole 132. A rotary valve, sealing flap, or electric rocker arm can usually be used. The control mechanism allows the middle layer medium conveying hole 132 to open to allow medium flow, or to close to isolate the medium between the cooling pool 11 and the heat exchange pool 12. This ensures that the cooling pool 11 can always supply medium to the heat exchange pool 12 through the middle layer medium conveying hole. During the medium conveying process using the middle layer medium conveying hole 132, impurities on the upper and lower surfaces of the medium in the heat exchange pool 12 will not cause significant turbulence, thus reducing the time required for impurity sedimentation and allowing direct extraction of the medium from the heat exchange pool 12. The closing unit 133 can be driven by a motor. The specific driving method of the closing unit 133 is not limited here. It should be noted that if an electric drive is used, the motor should be placed on the upper layer of the medium, and a mechanical drive rod should be placed at the closing unit 133 to avoid direct contact between the motor and the medium, which would reduce its service life.

[0022] Furthermore, the surface medium conveying hole 131 is located above the middle medium conveying hole 132. After the surface medium conveying hole 131 is opened, it is in a fixed position, and the water level in the corresponding cooling pool is at the maximum capacity height. At this time, the water level in the cooling pool 11 can be raised by injecting medium into the cooling pool 11. When the water level rises to the position of the surface medium conveying hole 131, the surface water in the cooling pool 11 can be continuously discharged into the heat exchange pool 12. During the discharge of surface water, floating impurities will be carried into the heat exchange pool 12 for subsequent cleaning.

[0023] Furthermore, the circulation module 1 also includes a transport tank 14, which receives the medium after heat exchange in the heat exchange zone 2. The transport tank 14 transports the medium into the cooling tank 11, thereby realizing the circulation of the medium in the transport tank 14, the heat exchange zone 12, and the cooling tank 11. Specifically, the cooling tank 11 transports the medium into the heat exchange zone 12, the heat exchange zone 12 injects the medium into the heat exchange zone 2, and then the medium travels from the heat exchange zone 2 to the transport tank 14. Finally, the medium in the transport tank 14 is transported to the cooling tank 11 to complete the entire circulation process.

[0024] Furthermore, it also includes several sets of conveying pipes d, which connect the cooling pool 11, the heat exchange pool 12, the heat exchange zone 2, and the conveying pool 14 for media transport. The conveying pipes d output power by connecting to the extraction pump. A filter screen is installed at the end of the conveying pipes d to reduce the risk of impurities being extracted and affecting the operation of the equipment.

[0025] Specifically, the conveying pipe d connecting the cooling pool 11 to the heat exchange pool 12 should be located in the middle layer of the medium at both ends. The middle layer specifically refers to the area below the water surface that avoids floating impurities and the area above the bottom of the pool that avoids sediment impurities. The conveying pipe d is set up here to slowly pump water, which can reduce turbulence to a greater extent. It is generally used when the cooling pool 11 is cooled down slightly.

[0026] It should be noted that the temperature of the medium in the cooling pool 11 is constantly changing, and the magnitude of the rise and fall is also different. The cooling pool 11 is equipped with a temperature detection system, which can monitor the temperature inside the cooling pool 11 at all times. This is common knowledge in the field and will not be elaborated on here. During operation, the staff will observe the specific temperature situation inside the cooling pool 11. Based on the temperature situation, the water replacement in the cooling pool 11 can be handled in a targeted manner. For example, if the temperature rises slowly, a small amount of water can be drawn out through the delivery pipe d. After the water is drawn out, it can be quickly transported through the delivery pipe d connecting the heat exchange pool 12 to the heat exchange zone 2 for rapid heat exchange. Since the medium in the cooling pool 11 is transported to the heat exchange pool 12 through the delivery pipe d, the turbulence amplitude is small. Therefore, this part of the medium can be used directly without clogging or damaging the heat exchange equipment. If the temperature of the medium in the cooling pool 11 changes significantly and rises rapidly, the medium can be transported directly through the middle layer medium delivery hole 132.

[0027] Furthermore, it also includes a cooling tank 3, which stores a cooling medium. A heat exchanger 21 is installed in the heat exchange zone 2. The input end of the heat exchanger 21 receives the medium in the heat exchange pool 12 through the delivery pipe d. The cooling tank 3 injects the medium into the input end of the heat exchanger 21 through the heat exchange zone 2 via a pipe. In this scheme, the heat exchanger 21 is a plate heat exchanger. Liquid nitrogen is stored in the cooling tank 3. Liquid nitrogen can be used for heat exchange and cooling, or other condensate can be used to achieve rapid heat exchange. The cooling medium can be injected here according to the specific situation. There is no specific limitation on the cooling medium stored in the cooling tank 3.

[0028] Furthermore, holes are made through the side wall of the heat exchange zone 2, and exhaust fans 22 are installed at the holes. Since nitrogen and other gases and heat are generated during the heat exchange process, exhaust fans 22 are needed to dissipate heat from the gases, exhaust rapidly expanding nitrogen, avoid overpressure of the equipment, remove nitrogen residue in the heat exchange zone, ensure heat exchange efficiency, and prevent low-temperature nitrogen from damaging equipment components.

[0029] Specifically, the cooling pool 11, the heat exchange pool 12, and the transport pool 14 can all store media. When the heat exchange pool 12 is not storing media, its internal impurities can be cleaned. For example, at this time, the heat exchange pool 12 does not need to exchange heat, and the media in the heat exchange pool 12 is in a state of precipitated impurities. The media in the cooling pool 11 is in a normal working state. When the heat exchange pool 12 needs to be cleaned of impurities, heat exchange can be carried out. The media after heat exchange in the heat exchange pool 12 is transported to the transport pool 14 for storage. The state of media storage in the heat exchange pool 12 and the transport pool 14 can meet the existing static cooling state. Furthermore, after the heat exchange pool 12 is statically cooled, only a small amount of liquid nitrogen needs to be injected during the heat exchange process through the heat exchanger 21 to achieve the cooling effect, thereby greatly reducing the temperature. To reduce costs, when the medium in the heat exchange tank 12 is transported to the heat exchange tank 11, impurities in the heat exchange tank 12 can be cleaned. Note that the medium in the heat exchange tank 12 cannot be completely extracted to avoid clogging of the heat exchanger 21. However, the medium in the heat exchange tank 12 can be extracted to an area accessible to personnel for retrieval and cleaning of impurities. Alternatively, the transport pipes d of the heat exchange tank 12 and the cooling tank 11 can be reversed to transport the small amount of medium remaining after being pumped to the heat exchanger 21 back to the cooling tank 11. Then, personnel can enter the heat exchange tank 12 to process and clean the impurities. Similarly, multiple sets of transport pipes d can be set up at this location for drainage and pumping operations, depending on the site conditions.

[0030] Furthermore, when the medium in cooling pool 11 needs heat exchange, the medium in the corresponding area of ​​the closed unit 133 is taken out by opening the closed unit 133, reducing floating and sedimented impurities in cooling pool 11. The extraction pump is then started to transport the medium to the heat exchanger through the delivery pipe d, and after heat exchange, it is discharged to the waiting-to-transfer pool 14. Subsequently, the medium in the waiting-to-transfer pool 14 is transported back to cooling pool 11. This is mainly used for rapid and multiple heat exchange processes. If the temperature of the medium in cooling pool 11 rises rapidly, the closed unit 133 can be opened to increase the flow rate of the medium, allowing it to quickly reach the waiting-to-transfer pool 12. At the same time, liquid nitrogen is continuously injected into the heat exchanger 21 from the cooling tank 3, and liquid nitrogen is also transferred from the waiting-to-transfer pool 14 to the cooling pool through the delivery pipe d. The medium after heat exchange is injected into the cooling pool 11 at all times. This process mainly involves opening and closing unit 133 to ensure that the liquid level of the cooling pool 11 and the heat exchange pool 12 is always the same. That is, the delivery pipe d directly draws the medium stored in both the heat exchange pool 12 and the cooling pool 11. Since the heat exchange pool 12 and the cooling pool 11 are connected at this time, the liquid level changes synchronously. At this time, the heat exchange process can be carried out without gaps, ensuring high efficiency. In this scheme, the number and size of the heat exchangers 21 are not specifically limited and can be set according to the actual situation. Multiple sets of heat exchangers 21 can also be selected, but each set of heat exchangers can be operated independently. At this time, the staff can make more choices to deal with the heat exchange method in different situations.

[0031] In summary, rapid heat exchange is achieved through media circulation between the cooling pool 11, the heat exchange tank 12, and the transport tank 14. When the temperature of the medium in the cooling pool 11 rises and needs to be rapidly cooled, the closed unit 133 on the middle layer medium transport hole 132 is opened. At this time, the middle layer medium in the cooling pool 11 is taken out, thus avoiding floating objects and sediments in the cooling pool. The heat exchange tank 12 is filled with medium by rapidly taking out water. Due to the liquid level difference, the liquid level in the heat exchange tank 12 can rise rapidly, and only a small amount of turbulence is generated on the water surface and bottom. Then, the medium is transported through the transport pipe d. The medium is transported to the heat exchanger 21, and the cooling medium in the cooling tank 3 is simultaneously input into the heat exchanger 21 to achieve heat exchange between the two. Finally, the cooled medium is discharged into the waiting tank 14. When the water level in the cooling tank 11 is kept at a normal level, sufficient water can be stored in the waiting tank 12 for cooling. After cooling, the water is output through the heat exchanger 21 to the waiting tank 11 for the next use. This process does not require the injection of medium into the cooling tank 3, which can greatly reduce costs and speed up heat exchange efficiency. It also offers more options and can be adapted to different heat exchange scenarios according to various conditions such as the rate of temperature rise and the magnitude of temperature rise.

[0032] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A circulating cooling device, characterized in that: include, The circulation module (1) includes a cooling pool (11) and a heat exchange pool (12). The heat exchange zone (2) transfers the medium in the cooling pool (11) back to the cooling pool (11) after heat exchange. A through-hole unit (13) is provided between the cooling pool (11) and the heat exchange pool (12). The through-hole unit (13) is used to transport media at different depths in the cooling pool (11) and avoid impurities at different depths.

2. The circulating cooling device according to claim 1, characterized in that: The through-hole unit (13) includes a surface medium delivery hole (131) and a middle medium delivery hole (132). A safety line is installed inside the cooling pool (11) to ensure that the medium to be cooled inside the cooling pool (11) is always covered; The bottom of the middle layer medium delivery hole (132) is set horizontally with the safety line, and a closing unit (133) is provided at the middle layer medium delivery hole (132).

3. The circulating cooling device according to claim 2, characterized in that: The surface medium delivery hole (131) is located above the middle medium delivery hole (132).

4. The circulating cooling device according to any one of claims 1 to 3, characterized in that: The circulation module (1) also includes a transport tank (14), which receives the medium after heat exchange output from the heat exchange zone (2); The tank to be transported (14) transports the medium into the cooling tank (11).

5. The circulating cooling device according to claim 4, characterized in that: It also includes several sets of conveying pipes (d), which connect the cooling pool (11), the heat exchange pool (12), the heat exchange zone (2) and the conveying pool (14) for medium transport. The delivery pipe (d) outputs power through a pump; A filter screen is provided at the end of the conveying pipe (d).

6. The circulating cooling device according to claim 5, characterized in that: It also includes a cooling tank (3) which stores a cooling medium; A heat exchanger (21) is provided in the heat exchange zone (2), and the input end of the heat exchanger (21) receives the medium in the heat exchange pool (12) through the delivery pipe (d); The cooling tank (3) is injected into the heat exchanger (21) through a pipe through the heat exchange zone (2).

7. The circulating cooling device according to claim 6, characterized in that: The heat exchange zone (2) has holes through its sidewalls, and exhaust fans (22) are installed at the holes.

8. A cyclic method, characterized in that: It is applied to the circulating cooling device according to any one of claims 1 to 7; and wherein the cooling pool (11), the heat exchange pool (12) and the transport pool (14) can all store the medium; When no medium is stored in the heat exchange pool (12), the impurities inside can be cleaned.

9. The cyclic method according to claim 8, characterized in that: The surface impurities of the cooling pool (11) need to be cleaned. The medium is injected into the cooling pool (11) through the transport pool (14). The surface medium in the cooling pool (11) is discharged into the heat exchange pool (12) through the surface medium transport hole (131). The bottom medium in the cooling pool (11) is then extracted through the transport pipe (d) and transported to the heat exchanger (21) for heat exchange. Finally, it is transported to the transport pool (14) for storage. Then, the impurities in the heat exchange pool (12) are cleaned.

10. The cyclic method according to claim 8, characterized in that: When the medium in the cooling pool (11) needs to exchange heat, the medium in the corresponding area of ​​the closed unit (133) is taken out by opening the closed unit (133) to reduce the floating impurities and sediment impurities in the cooling pool (11), and the pump is started to transport the medium to the heat exchanger through the delivery pipe (d) for heat exchange and then discharge it to the delivery pool (14). Then the medium in the delivery pool (14) is transported back to the cooling pool (11).

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