Water-side heat exchange natural convection strengthening device and spent fuel pool cooling system

Abstract

The utility model discloses a kind of water side heat exchange natural convection reinforcement device and spent fuel pool cooling system, the water side heat exchange natural convection reinforcement device includes water side reinforcement heat exchange device, the water side reinforcement heat exchange device includes multiple heat exchange pipes and the same number of reinforcement structure with the multiple heat exchange pipes, the heat exchange pipe is set in the reinforcement structure, the reinforcement structure is defined with the heat exchange pipe between two ends unsealed drainage channel;The multiple heat exchange pipes are filled with water;The utility model increases reinforcement structure outside heat exchange pipe, so that the hot water of spent fuel pool flows better in reinforcement structure, to increase the water exchange of hot water and heat exchange pipe in.

Description

Technical Field

[0001] This utility model relates to the field of nuclear power, and in particular to a water-side heat exchange natural convection enhancement device and a spent fuel pool cooling system. Background Technology

[0002] In severe accident conditions, spent fuel water pools require a cooling system to cool the hot water within. In related technologies, the cooling system includes a heat exchanger filled with a working fluid; the working fluid in the heat exchanger exchanges heat with the hot water in the spent fuel water pool, and other equipment in the cooling system cools the working fluid after the heat exchange. However, the heat exchange efficiency between the heat exchanger and the spent fuel water pool is poor. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a water-side heat exchange natural convection enhancement device and a spent fuel water tank cooling system.

[0004] The technical solution adopted by this utility model to solve its technical problem is: A water-side heat exchange natural convection enhancement device, comprising: A water-side enhanced heat exchange device includes multiple heat exchange tubes and the same number of reinforcing structures as the multiple heat exchange tubes. The heat exchange tubes are disposed within the reinforcing structures, and a flow channel with open ends is defined between the reinforcing structures and the heat exchange tubes. The multiple heat exchange tubes are filled with water.

[0005] Furthermore, the water-side heat exchange natural convection enhancement device preferably also includes an upper tube and a lower tube; the two ends of the multiple heat exchange tubes are respectively connected to the upper tube and the lower tube.

[0006] Furthermore, in the aforementioned water-side heat exchange natural convection enhancement device, preferably, multiple drainage channels are defined, and the enhancement structure includes a cylindrical body, multiple inner baffles, and an expansion joint. The expansion joint is disposed within the body, and the plurality of inner baffles are spaced apart between the body and the expansion joint. The heat exchange tube passes through the expansion joint. The body, the plurality of inner baffles, and the expansion joint together define the plurality of drainage channels.

[0007] Furthermore, in the water-side heat exchange natural convection enhancement device, the enhancement structure preferably includes a plurality of outer partitions respectively spaced apart on two opposite sides of the main body, and a plurality of flow channels are defined between two adjacent main bodies and the plurality of outer partitions.

[0008] A spent fuel water tank cooling system includes the aforementioned water-side heat exchange natural convection enhancement device.

[0009] Furthermore, the spent fuel water pool cooling system preferably also includes a spent fuel water pool, a cooling heat exchange device, and a circulation pipeline; The spent fuel water tank is filled with hot water. The water-side enhanced heat exchange device is installed inside the spent fuel water tank, and the cooling heat exchange device is installed outside the spent fuel water tank. The circulation pipe connects the water-side enhanced heat exchange device and the cooling heat exchange device in a circulating manner.

[0010] Furthermore, in the aforementioned spent fuel water pool cooling system, preferably three water-side enhanced heat exchange devices are provided and distributed on the inner wall around the spent fuel water pool, with the two ends of the three water-side enhanced heat exchange devices connected sequentially to the circulation pipe.

[0011] Furthermore, in the aforementioned spent fuel water tank cooling system, preferably the upper pipe is connected to the inlet end of the cooling heat exchange device via the circulation pipe, and the lower pipe is connected to the outlet end of the cooling heat exchange device via the circulation pipe.

[0012] Furthermore, the spent fuel water pool cooling system preferably further includes a water replenishment component, which includes a water replenishment pipe connected to the circulation pipe and a water replenishment tank connected to the water replenishment pipe. The water replenishment tank has an unclosed opening and stores water inside.

[0013] Furthermore, the spent fuel water tank cooling system preferably also includes a valve assembly disposed on the circulation pipe, the valve assembly including a first valve and a second valve; A first valve is installed on the circulation pipe connected to the inlet end of the cooling heat exchange device; a second valve is installed on the circulation pipe connected to the outlet end of the cooling heat exchange device.

[0014] The present invention has the following advantages: adding a reinforcing structure to the outside of the heat exchange tube allows the hot water in the spent fuel water tank to flow better within the reinforcing structure, thereby increasing the heat exchange between the hot water and the water in the heat exchange tube.

[0015] The water in the water-side enhanced heat exchanger is heated by the high-temperature water in the spent fuel pool, increasing its temperature and decreasing its density. It then flows upward through the circulation pipe into the cooling heat exchanger to exchange heat with the outside air. After cooling, its temperature decreases and its density increases. It then flows downward through the circulation pipe back to the water-side enhanced heat exchanger to exchange heat with the spent fuel pool again and increase its temperature. Relying on natural circulation without any external force, the cycle repeats continuously, achieving natural circulation of water in the circulation pipe. During the circulation process, only heat exchange occurs, not mass exchange. This ensures that the high-temperature heat from the spent fuel pool is discharged in a timely manner after an accident, providing a sufficient window of opportunity for subsequent accident handling and ensuring that no nuclear leakage occurs. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a three-dimensional structural schematic diagram of the water-side heat exchange natural convection enhancement device and the spent fuel water pool cooling system in some embodiments of this utility model. Figure 2 yes Figure 1 A three-dimensional structural schematic diagram of the enhanced heat exchange device shown. Figure 3 yes Figure 2 A schematic cross-sectional view of the enhanced heat exchange device shown. Figure 4 yes Figure 2 A three-dimensional structural diagram of the reinforced structure shown. Detailed Implementation

[0017] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or component referred to must have a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0018] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0019] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the art will understand that the present invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0020] The technical solution adopted by this utility model to solve its technical problem is: like Figures 1 to 2 As shown in the figure, some embodiments of this utility model disclose a water-side heat exchange natural convection enhancement device and a spent fuel water tank cooling system. The water-side heat exchange natural convection enhancement device and spent fuel water tank cooling system include a spent fuel water tank 10, three water-side enhanced heat exchange devices 20, a cooling heat exchange device 30, and a circulation pipe 40. The three water-side enhanced heat exchange devices 20 and the circulation pipe 40 are filled with water. The three water-side enhanced heat exchange devices 20 are distributed on the inner walls surrounding the spent fuel water tank 10. The water in the three water-side enhanced heat exchange devices 20 is used to enhance heat exchange and raise the temperature of the hot water in the spent fuel water tank 10. The distributed arrangement effectively increases the heat exchange area.

[0021] The cooling heat exchange device 30 is located outside the spent fuel water pool 10, and the cooling heat exchange device 30 is positioned higher than the spent fuel water pool 10. Three water-side enhanced heat exchange devices 20 are connected to the cooling heat exchange device 30 through circulation pipes 40. The cooling heat exchange device 30 is in contact with the outside air. After the water in the three water-side enhanced heat exchange devices 20 is heated by heat exchange, the density of the water decreases and it flows upward through the circulation pipes 40 into the cooling heat exchange device 30, where it is cooled by heat exchange with the outside air.

[0022] Refer again Figure 1 The cooling heat exchange device 30 is connected to three water-side enhanced heat exchange devices 20 through the circulation pipe 40. After the water in the cooling heat exchange device 30 exchanges heat with the outside air and cools down, the density of the water increases and flows back down through the circulation pipe 40 to the three water-side enhanced heat exchange devices 20 for heat exchange and heating up again.

[0023] This application utilizes the natural law that allows water to flow upwards into the cooling heat exchange device 30 after being heated, increasing its temperature and density; and then flowing downwards back to the three water-side enhanced heat exchange devices 20 after being cooled, decreasing its temperature and increasing its density. This natural cycle, without any external force, continuously achieves the natural circulation of water within the three enhanced cooling heat exchange devices 20, the cooling heat exchange device 30, and the circulation pipe 40. During this circulation, only heat exchange occurs, not mass exchange. This enhances the heat exchange in the spent fuel pool 10, ensuring the timely removal of high-temperature heat from the spent fuel pool 10 after an accident, providing a sufficient window of opportunity for subsequent accident handling, and ensuring no nuclear leakage occurs.

[0024] Continue to refer to Figure 1 In some embodiments, the water-side natural convection enhanced heat exchange spent fuel water pool cooling system may also include a water replenishment assembly 50 and a valve assembly 60. The water replenishment assembly 50 is located at the highest point of the circulation pipe 40 and is used to replenish water lost within the circulation pipe 40. The valve assembly 60 is located on the circulation pipe 40 and is used to control the flow within the circulation pipe 40.

[0025] In some embodiments, the spent fuel water tank 10 has multiple spent fuel elements (fuel rods) spaced apart at the bottom and is filled with cooling water. The cooling water can absorb the heat of the spent fuel elements to cool them down.

[0026] like Figure 2 and Figure 3As shown, in some embodiments, the water-side enhanced heat exchange device 20 may include an upper pipe 21, multiple heat exchange tubes 22, a lower pipe 23, and multiple enhanced structures 24. The upper pipe 21 is connected to the inlet end of the cooling heat exchange device 30 via a circulation pipe 40. The upper pipe 21, the multiple heat exchange tubes 22, and the lower pipe 23 are filled with water; one end of each of the multiple heat exchange tubes 22 is connected to the upper pipe 21, and the other end is connected to the lower pipe 23. The lower pipe 23 is connected to the outlet end of the cooling heat exchange device 30 via the circulation pipe 40. The number of enhanced structures 24 is the same as the number of heat exchange tubes 22. The heat exchange tubes 22 are vertically arranged within the enhanced structures 24, and an open-ended drainage channel 240 is defined between the inner wall of the enhanced structure 24 and the outer wall of the heat exchange tubes 22. It is understood that the enhanced structure 24 is cylindrical. Hot water in the spent fuel water tank 10 flows through the drainage channel 240. The upper pipe 21, multiple heat exchange tubes 22, and lower pipe 23 come into contact with the water in the spent fuel water tank 10. The water in the upper pipe 21, multiple heat exchange tubes 22, and lower pipe 23 exchanges heat with the hot water flowing into the drainage channel 240 and is heated. The density of the heated water decreases, and the water in the multiple heat exchange tubes 22 enters the upper pipe 21. The water in the upper pipe 21 enters the cooling heat exchange device 30 after passing through the circulation pipe 40 and is cooled. The density of the cooled water decreases, and it enters the lower pipe 23 after passing through the circulation pipe 40. The water in the lower pipe 23 exchanges heat with the water in the spent fuel water tank 10 again and is heated before returning to the multiple heat exchange tubes 22.

[0027] Hot water from the spent fuel water tank 10 enters from the upper part of the reinforced structure 24 (drainage channel 240) and flows downward to exchange heat with the water in the heat exchange tube 22. It then flows out from the lower part of the reinforced structure 24 to enhance autonomous heat exchange.

[0028] In some embodiments, the upper pipe 21, multiple heat exchange pipes 22, and lower pipe 23 are made of materials with high thermal conductivity, which can better absorb the heat from the hot water in the spent fuel water tank 10 and conduct the heat to the water inside. For example, copper, copper alloys, carbon steel, etc.

[0029] For reference Figure 4In some embodiments, the reinforcing structure 24 vertically defines multiple drainage channels 240 with open ends. In some embodiments, the reinforcing structure 24 may include a cylindrical body 241, multiple inner baffles 242, multiple outer baffles 243, and an expansion joint 244. The expansion joint 244 is vertically disposed in the middle of the body 241, and the multiple inner baffles 242 are spaced apart between the body 241 and the expansion joint 244. In other words, one end of the multiple inner baffles 242 is circumferentially spaced on the outer surface of the expansion joint 244, and the other end is spaced apart on two opposite sides inside the body 241. A heat exchange tube 22 passes through the expansion joint 244. The body 241, the multiple inner baffles 242, and the expansion joint 244 together define multiple drainage channels 240. Understandably, the hot water in the spent fuel water tank 10 flows within the multiple drainage channels 240, which forces the fluid to be distributed more evenly across the entire flow cross-section, ensuring uniformity of flow rate and heat exchange. Multiple outer baffles 243 are spaced apart on opposite sides of the main body 241. The multiple outer baffles 243 on adjacent main bodies 241 together define multiple flow channels 240. This allows the hot water fluid to flow more evenly between adjacent main bodies 241, increasing the fluidity of the hot water. Furthermore, it allows the flowing hot water to transfer heat to the main body 241, and then the main body 241 transfers heat to the hot water within the flow channels 240.

[0030] The addition of a reinforcing structure 24 to the heat exchange tube 22 maximizes the heat exchange capacity with the hot water in the spent fuel water tank 10. The hot water from the spent fuel water tank 10 enters the unsealed upper end of the drainage channel 240 and exchanges heat with the water in the heat exchange tube 22. Due to the guiding effect of the drainage channel 240, the downward flow of the hot water is enhanced, and it flows out at the unsealed lower end of the drainage channel 240, thereby achieving enhanced self-heating capacity. In some embodiments, the outer peripheral wall of the reinforcing structure 24 is either serrated or a continuously connected V-shaped structure. In other embodiments, the reinforcing structure 24 is a structure formed by two W-shaped joints.

[0031] It should be noted that the heat exchange tube 22 is inserted into the expansion tube 244 using an expansion joint process. The inner diameter of the expansion tube 244 is smaller than the outer diameter of the heat exchange tube 22. After heating the expansion tube 244, its inner diameter expands and then the heat exchange tube 22 is inserted into the expansion tube 244, so that the expansion tube 244 and the heat exchange tube 22 fit tightly together, thus avoiding the problem of excessive thermal resistance.

[0032] Continue to refer to Figure 1In some embodiments, the inlet end of the cooling heat exchanger 30 is higher than the outlet end of the cooling heat exchanger 30 to increase the flow of water after cooling. In some embodiments, water heated by heat exchange in the water-side enhanced heat exchanger 20 enters the cooling heat exchanger 30, and outside air enters the cooling heat exchanger 30 to exchange heat with the water inside the cooling heat exchanger 30 and then flows out from the outlet end of the cooling heat exchanger 30; while the heated air is discharged from the cooling heat exchanger 30. In some embodiments, a fan is installed inside the cooling heat exchanger 30, and the fan generates negative pressure to draw air into the cooling heat exchanger 30. The air enters from one end of the cooling heat exchanger 30, undergoes heat exchange, and then exits from the other end.

[0033] Refer again Figure 1 In some embodiments, the circulation pipe 40 may include a first pipe 41, a second pipe 42, a third pipe 43, and a fourth pipe 44. One end of the first pipe 41 is connected to the upper pipe 21. The two ends of the second pipe 42 are respectively connected to the other end of the first pipe 41 and the inlet end of the cooling heat exchanger 30. The two ends of the third pipe 43 are respectively connected to the outlet end of the cooling heat exchanger 30 and one end of the fourth pipe 44. The other end of the fourth pipe 44 is connected to the lower pipe 23. In some embodiments, the number of first pipes 41 and fourth pipes 44 is the same as the number of water-side enhanced heat exchangers 20. Three water-side enhanced heat exchangers 20 are provided with three first pipes 41 and three fourth pipes 44. One end of each of the three first pipes 41 is connected to the top of the upper pipe 21 of each of the three water-side enhanced heat exchangers 20, and the other end is connected to the second pipe 42, so that the heated water in the three water-side enhanced heat exchangers 20 is transported through the three first pipes 41 to the second pipe 42, and then the second pipe 42 transports the water to the cooling heat exchanger 30. One end of each of the three fourth pipes 44 is connected to the lower pipe 23 of each of the three water-side enhanced heat exchange devices 20, and the other end is connected to the third pipe 43. After the water cooled by the cooling heat exchange device 30 enters the third pipe 43, it enters the lower pipe 23 of each of the three water-side enhanced heat exchange devices 20 through the three fourth pipes 44.

[0034] like Figure 1 As shown, in some embodiments, the water replenishment component 50 may include a water replenishment pipe 51 and a water replenishment tank 52 connected to the water replenishment pipe 51. The water replenishment tank 52 has an open opening and stores water. In some embodiments, the water replenishment tank 52 is located at the highest point of the circulation pipe 40. Understandably, the water replenishment tank 52 is not sealed and has sufficient space, mainly to ensure that the water in the circulation system (circulation pipe 40) does not overflow due to the expansion of water volume caused by heating under operating conditions and to replenish water in a timely manner when the water is insufficient.

[0035] Refer again Figure 1In some embodiments, valve assembly 60 may include a first valve 61 disposed on the second pipe 42 and a second valve 62 disposed on the third pipe 43. Understandably, in the event of a malfunction and no external input, simply opening both valves (the first valve 61 and the second valve 62) allows for natural circulation cooling of the hot water in the spent fuel water tank 10 without external force or input, thus enabling heat exchange.

[0036] It should be noted that, for those skilled in the art, without departing from the concept of this utility model, the above-mentioned technical features can be freely combined, and several modifications and improvements can be made, all of which fall within the protection scope of this utility model.

Claims

1. A water-side heat exchange natural convection enhancement device, characterized in that, include: A water-side enhanced heat exchange device (20) includes multiple heat exchange tubes (22) and the same number of enhanced structures (24) as the multiple heat exchange tubes (22). The heat exchange tubes (22) are disposed within the enhanced structures (24). A drainage channel (240) with open ends is defined between the enhanced structures (24) and the heat exchange tubes (22). The multiple heat exchange tubes (22) are filled with water.

2. The water-side heat exchange natural convection enhancement device according to claim 1, characterized in that, It also includes an upper tube (21) and a lower tube (23); the two ends of the multiple heat exchange tubes (22) are respectively connected to the upper tube (21) and the lower tube (23).

3. The water-side heat exchange natural convection enhancement device according to claim 1, characterized in that, The drainage channel (240) is defined in multiple ways, and the reinforcing structure (24) includes a cylindrical body (241), multiple inner partitions (242), and an expansion joint (244). The expansion joint (244) is disposed inside the body (241), the plurality of inner partitions (242) are spaced apart between the body (241) and the expansion joint (244), and the heat exchange tube (22) passes through the expansion joint (244); the body (241), the plurality of inner partitions (242) and the expansion joint (244) together define the plurality of drainage channels (240).

4. The water-side heat exchange natural convection enhancement device according to claim 3, characterized in that, The reinforced structure (24) also includes a plurality of outer partitions (243) that are spaced apart on opposite sides of the body (241), and a plurality of drainage channels (240) are defined between two adjacent bodies (241) and the plurality of outer partitions (243).

5. A spent fuel water tank cooling system, characterized in that, Includes the water-side heat exchange natural convection enhancement device as described in any one of claims 1 to 4.

6. The spent fuel water tank cooling system according to claim 5, characterized in that, It also includes a spent fuel water tank (10), a cooling heat exchange device (30), and a circulation pipeline (40). The spent fuel water tank (10) is filled with hot water. The water-side enhanced heat exchange device (20) is installed inside the spent fuel water tank (10). The cooling heat exchange device (30) is installed outside the spent fuel water tank (10). The circulation pipe (40) circulates between the water-side enhanced heat exchange device (20) and the cooling heat exchange device (30).

7. The spent fuel water tank cooling system according to claim 6, characterized in that, Three water-side enhanced heat exchange devices (20) are provided and are distributed on the inner wall around the spent fuel water tank (10). The two ends of the three water-side enhanced heat exchange devices (20) are connected to the circulation pipe (40) in sequence.

8. The spent fuel water tank cooling system according to claim 7, characterized in that, The upper pipe (21) is connected to the inlet end of the cooling heat exchange device (30) through the circulation pipe (40), and the lower pipe (23) is connected to the outlet end of the cooling heat exchange device (30) through the circulation pipe (40).

9. The spent fuel water tank cooling system according to claim 6, characterized in that, It also includes a water replenishment component (50), which includes a water replenishment pipe (51) connected to the circulation pipe (40) and a water replenishment tank (52) connected to the water replenishment pipe (51). The water replenishment tank (52) has an unclosed opening and stores water inside.

10. The spent fuel water tank cooling system according to claim 6, characterized in that, It also includes a valve assembly (60) disposed on the circulation pipe (40), the valve assembly (60) including a first valve (61) and a second valve (62); The first valve (61) is provided on the circulation pipe (40) connected to the inlet end of the cooling heat exchange device (30); the second valve (62) is provided on the circulation pipe (40) connected to the outlet end of the cooling heat exchange device (30).

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