A containment dome heat exchange device

Abstract

The present invention relates to a containment dome heat exchange device, comprising a heat pipe, a base, and a steel lining. The heat pipes are multiple, spaced apart, and disposed within the dome concrete. Each of the heat pipes extends beyond the dome concrete to form a condensation section. The base is disposed at the end of the heat pipe away from the condensation section. The heat pipe is connected to the steel lining via the base. The end of the steel lining away from the condensation section is provided with a heat exchange rib, each provided with a first fin. The condensation section is provided with a second fin. The use of the containment dome heat exchange device of the present invention improves the passive safety of the containment. It can also form a natural convection circulation in the dome area, alleviating the accumulation of heat and hydrogen.

Description

Technical Field

[0001] The invention belongs to the technical field of heat exchange, and in particular relates to a containment dome heat exchange device. Background Art

[0002] The containment vessel of an existing pressurized water reactor nuclear power plant is a tall and large space, and heat is easily accumulated in the dome. According to operating data, the air temperature in the dome is much higher than the average air temperature in the containment vessel. Continuous high temperature may have an adverse effect on process equipment and concrete structures.

[0003] Currently, forced convection mixing of dome air is often achieved through the use of powered fans. However, due to the lack of local cooling, temperature gradients remain significant. Furthermore, a power outage or equipment failure renders the fans inoperable, further exacerbating the dome's temperature. The dome of a pressurized water reactor nuclear power plant serves as a radioactive containment barrier, requiring it to withstand high pressure and radioactive leaks. Due to the thickness of the concrete, the dome's thermal conductivity is extremely low, making it difficult to effectively transfer heat from the dome to the outside.

[0004] Some have installed elevated water tanks within the dome to remove heat from the dome through spraying and natural ventilation after an accident, creating natural air circulation to reduce temperature and hydrogen concentration. However, these structures are complex, require high investment, and rely heavily on a water storage source, making them ineffective in dissipating heat during normal operation. Summary of the Invention

[0005] In response to the defects in the prior art, the purpose of the present invention is to provide a containment dome heat exchange device, which uses heat pipes and enhanced heat exchange devices to conduct reactor waste heat through the dome to the outdoor air source, while establishing a natural ventilation cycle in the dome to alleviate heat and hydrogen accumulation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a containment dome heat exchange device includes a heat pipe, a base and a steel lining, wherein the number of the heat pipes is multiple, and there are intervals between the multiple heat pipes, which are arranged in the dome concrete, and the multiple heat pipes all extend out of the dome concrete to form a condensation section; the base is arranged at the end of the heat pipe away from the condensation section, the heat pipe is connected to the steel lining through the base, and the steel lining is provided with a heat exchange rib on the end away from the condensation section, the heat exchange rib is provided with a first fin, and the condensation section is provided with a second fin.

[0007] Furthermore, a waterproof seal is provided between the condensation section and the dome concrete.

[0008] Furthermore, the heat pipe includes an inner shell and a sleeve. The sleeve is arranged in the dome concrete and connected to the steel lining. The inner shell is exposed outside the dome concrete and is threadedly connected to the sleeve.

[0009] Furthermore, the heat pipe includes an inner shell and a sleeve, the sleeve is arranged in the dome concrete and connected to the steel lining; the inner shell is exposed outside the dome concrete and is integrally formed with the sleeve, and a head is provided at one end of the inner shell away from the sleeve, so that the heat pipe can be injected, vacuumed and repaired on site through the head.

[0010] Furthermore, the second fin is provided on the inner shell.

[0011] Furthermore, the inner shell is also connected to a lightning protection system.

[0012] Furthermore, a limiting cavity is provided on the head, and a sealing port and a card interface that penetrates the limiting cavity are provided on the limiting cavity, the sealing port is located at one end close to the inner shell, and the card interface is located on the opposite side of the sealing port, and a sealing cover is provided on the end of the head close to the card interface, and the sealing cover is connected to the head to close the card interface; a sealing assembly is provided in the limiting cavity, and the sealing assembly includes a sealing block, a clamp and a spring, one end of the clamp is connected to the sealing block through the spring, and a side of the sealing block away from the spring is used to close or open the sealing port; wherein the clamp is adapted to the shape of the card interface, so that the clamp can be moved out of the limiting cavity from the sealing port or intercepted by the card interface in the limiting cavity by rotating the clamp, and when the clamp is intercepted at the card interface, the spring is in a compressed state.

[0013] Furthermore, the sealing assembly further comprises a sealing gasket, which is arranged on a surface of the sealing block away from the spring, so that the sealing port can be closed or opened by the sealing gasket.

[0014] Furthermore, the cover is threadedly connected to the head.

[0015] Furthermore, sealant is provided at the connection between the cover and the head.

[0016] The present invention passively removes some of the reactor's residual heat to an outdoor air source during normal operation and after accidents, reducing containment temperature and the capacity of active ventilation and cooling equipment. The amount of heat removed increases superlinearly with the dome temperature, further enhancing the passive safety of the containment. Natural convection circulation can also be generated in the dome area, mitigating heat and hydrogen accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic cross-sectional view of a containment dome heat exchange device according to the present invention;

[0018] Figure 2 is a schematic structural diagram of a heat pipe in an embodiment;

[0019] Figure 3 is a schematic structural diagram of a heat pipe in another embodiment;

[0020] Figure 4 It is a structural diagram when the head and cover are closed;

[0021] Figure 5 It is a structural diagram when the head and cover are opened;

[0022] Figure 6 This is a schematic diagram of the structure when injecting liquid through the head;

[0023] Figure 7 This is a schematic diagram of the structure when exhausting through the head.

[0024] Description of reference numerals:

[0025] 1. Heat pipe; 2. Dome concrete; 5. Heat pipe base; 6. Steel lining; 7. Heat exchange ribs; 8. First fin; 9. Condensation section; 10. Second fin; 11. End cap; 12. Waterproof plug; 13. Inner shell; 14. Casing; 17. Lightning protection wiring; 18. Cover; 19. Sealing block; 20. Clamp; 21. Spring; 22. Sealing gasket; 23. Limiting cavity; 24. Sealant DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1-7 As shown, the present invention provides a containment dome heat exchange device comprising a heat pipe 1, a base 5, and a steel liner 6. There are multiple heat pipes 1, spaced apart from each other, disposed within the dome concrete 2. Each of the heat pipes 1 extends out of the dome concrete 2 to form a condensation section 9. The base 5 is disposed at the end of the heat pipe 1 away from the condensation section 9. The heat pipe 1 is connected to the steel liner 6 via the base 5. Heat exchange ribs 7 are provided on the end of the steel liner 6 away from the condensation section 9. The heat exchange ribs 7 are provided with first fins 8, and the condensation section 9 is provided with second fins 10.

[0028] When the temperature inside the dome rises above the outdoor temperature, the heat inside the dome is transferred to the condensing section 9 through the portion of the heat pipe 1 located within the dome concrete 2 and the steel lining 6 for dissipation. The higher the dome temperature, the greater the heat transfer, effectively reducing the cooling capacity of the active ventilation system and providing a high level of passive safety. Simultaneously, natural convection circulation is generated within the dome, further enhancing the external surface heat transfer coefficient. By mixing the cool air inside the dome with the hot air below, the temperature gradient in the upper containment space is effectively reduced, improving the environmental conditions for the concrete and process equipment. It can also mitigate hydrogen accumulation after an accident, facilitating the normal operation of the hydrogen recombiner.

[0029] In this embodiment, the base 5 and the steel lining 6 are connected by welding. In other embodiments, the base 5 and the steel lining 6 can be connected in any manner as long as heat transfer can be ensured after the connection.

[0030] It can be understood that the heat pipe 1 maintains a certain distance from the concrete reinforcement and prestressed reinforcement to ensure that the concrete can be poured normally. If necessary, the heat pipe 1 can be bent at a small angle to avoid the reinforcement.

[0031] It is understandable that a blackbody radiation coating may be added to the heat exchange ribs 7 and the first fins 8 .

[0032] Furthermore, a waterproof seal 12 is provided between the condensation section 9 and the dome concrete to prevent corrosion of the steel bars inside the concrete by rainwater and salt spray.

[0033] Furthermore, the heat pipe 1 includes an inner shell 13 and a sleeve 14. The sleeve 14 is disposed in the dome concrete 2 and connected to the steel lining 6. The inner shell 13 is exposed outside the dome concrete 2 and is threadedly connected to the sleeve 14.

[0034] It is understood that the inner shell 13 is a copper tube and the sleeve 14 is made of stainless steel. The sleeve 14 only protects the inner shell 13 within the dome concrete 2. The sleeve 14 is pre-buried in the dome concrete 2. The sleeve 14 can be pre-buried first and then the inner shell 13 can be installed after the concrete pouring is completed.

[0035] It can be understood that, through the threaded connection between the inner shell 13 and the sleeve 14 , the heat pipe 1 can be replaced on site after failure.

[0036] Furthermore, in another embodiment, the heat pipe 1 includes an inner shell 13 and a sleeve 14. The sleeve 14 is disposed within the dome concrete 2 and connected to the steel liner 6. The inner shell 13 is exposed outside the dome concrete 2 and is integrally formed with the sleeve 14. A sealing head 11 is provided at the end of the inner shell 13 away from the sleeve 14, allowing on-site injection, vacuuming, and maintenance of the heat pipe 1.

[0037] Furthermore, the second fins 10 are disposed on the inner shell 13 .

[0038] Furthermore, the inner shell 13 is also connected to a lightning protection system 17 .

[0039] It can be understood that by connecting the inner shell 13 to the lightning protection system 17, it is possible to prevent lightning current from being introduced into the containment shell.

[0040] Furthermore, a limiting cavity 23 is provided on the head 11. A sealing port and a card interface are provided on the limiting cavity 23, which pass through the limiting cavity 23. The sealing port is located at one end close to the inner shell 13, and the card interface is located on the opposite side of the sealing port. A cover 18 is provided on the end of the head 11 close to the card interface, and the cover 18 is connected to the head 11 to close the card interface. A sealing assembly is provided in the limiting cavity 23, which includes a sealing block 19, a clamping member 20, and a spring 21. One end of the clamping member 20 is connected to the sealing block 19 via the spring 21, and the side of the sealing block 19 away from the spring 21 is used to close or open the sealing port. The clamping member 20 is adapted to the shape of the card interface so that the clamping member 20 can be moved out of the limiting cavity 23 from the sealing port or intercepted by the card interface in the limiting cavity 23 by rotating the clamping member 20. When the clamping member 20 is intercepted at the card interface, the spring 21 is in a compressed state.

[0041] Furthermore, the sealing assembly further includes a sealing gasket 22 , which is disposed on a surface of the sealing block 19 away from the spring 21 , so that the sealing opening can be closed or opened by the sealing gasket 22 .

[0042] It can be understood that by providing the sealing gasket 22, the reliability of the sealing can be increased.

[0043] In one embodiment, the card member 20 includes a rotating rod and a card block, one end of the rotating rod is connected to the card block, and the card block is connected to the sealing block 19 through a spring 21. The card interface is a rectangular through hole, and the card block is a rectangular parallelepiped and adapted to the shape of the card interface. When the rotating rod is rotated, thereby driving the length direction of the card block to be parallel to the length direction of the card interface, the card block can be moved out of the card interface. When the rotating rod is rotated, causing the length direction of the card block to form an angle with the length direction of the card interface, the card block is intercepted at the card interface.

[0044] It is understandable that in other embodiments, the card member 20 may have any structure as long as its shape is compatible with the card interface and the card member 20 can be moved out of the card interface or intercepted at the card interface by rotating it.

[0045] Furthermore, the cover 18 is threadedly connected to the head 11 .

[0046] Furthermore, a sealant is provided at the connection between the cover 18 and the head 11 .

[0047] It is understandable that the surface of the condensing section 9 of the heat pipe 1 can also be coated with an anti-corrosion and reflective coating to improve the corrosion resistance of the heat pipe in a salt spray environment, reduce the solar heat gain and condensation temperature of the heat pipe, and improve the efficiency of the heat pipe.

[0048] It can be understood that the base 5 is conical.

[0049] The working principle of the present invention is: when the head 11 needs to be opened, the cover 18 is unscrewed first, and the clamping member 20 will be clamped at the opening on the cavity 23 under the action of the spring 21. At this time, the spring 21 is not fully expanded, and the sealing block 19 can still ensure the seal between it and the lower opening of the cavity 23.

[0050] When liquid working fluid needs to be injected into the heat pipe, the clamping member 20 is rotated and removed from the clamping interface on the limiting cavity 23. A certain force is applied to disengage the sealing block 19 from the sealing port under the limiting cavity 23, and the injection tube is inserted into the limiting cavity 23 to fill the working fluid.

[0051] When it is necessary to establish a vacuum degree for the heat pipe after liquid injection, first reinstall the clamp 20 into the cavity, connect the exhaust joint to the head 11 through a thread, and connect the other end of the exhaust joint to the vacuum pump. After starting the vacuum pump, the sealing block 19 is separated from the sealing port under the limit cavity 23 under the action of suction, and the gas in the heat pipe 1 is extracted by the vacuum pump through the limit cavity 23. When the gas is extracted to the specified vacuum degree or saturated steam escapes, the vacuum pump is stopped. The sealing block 19 is re-engaged with the sealing port under the limit cavity 23 under the action of the spring 21 and the negative pressure in the heat pipe 1 to seal. The exhaust joint is removed, and the cover 18 and sealant 24 are reinstalled to complete the establishment of the vacuum degree of the heat pipe, and the heat pipe can be put into use.

[0052] When it is necessary to determine whether the heat pipe is faulty during inspection, the clamp 20 is pulled out from the limiting cavity. If the sealing block 19 easily breaks away from the sealing port under the limiting cavity 23, it proves that the heat pipe has leaked. This method can quickly and non-destructively diagnose whether the heat pipe is faulty.

[0053] The above examples demonstrate that the present invention can passively remove some of the reactor's residual heat to an outdoor air source during normal operation and after accidents, reducing containment temperature and the capacity of active ventilation and cooling equipment. Furthermore, the amount of heat removed increases superlinearly with the dome temperature, further enhancing the passive safety of the containment. Furthermore, natural convection circulation can be generated in the dome area, mitigating heat and hydrogen accumulation.

[0054] At the same time, the double-layer structure of the heat pipe assembly can improve the performance and life of the heat pipe. The outer steel shell can be in long-term contact with the concrete, avoiding corrosion and improving the structural strength of the heat pipe. The inner copper shell is compatible with the working fluid, avoiding the generation of non-condensable gases and improving the heat transfer performance of the heat pipe. When the condensation section uses a single-shell copper tube, it not only improves the heat transfer coefficient of the outer surface, but also acts as a lightning rod (belt) connected to the lightning protection system, reducing the risk of lightning strikes on the dome.

[0055] By adding anti-corrosion and reflective coatings on the surface of the heat pipe condensation section, the corrosion resistance of the heat pipe in a salt spray environment can be improved, and the solar heat gain and condensation temperature of the heat pipe can be reduced, thereby improving the efficiency of the heat pipe.

[0056] By setting a conical base at the end of the heat pipe evaporation section, the stability of the heat pipe installed on the steel lining before concrete pouring can be ensured, and the contact area between the heat pipe evaporation section and the steel lining can be expanded, reducing the heat transfer thermal resistance.

[0057] By arranging heat exchange ribs and the first fin on the air side of the steel lining and adding a blackbody radiation coating, the heat transfer coefficient on the air side inside the dome can be enhanced, further enhancing the heat extraction and convection circulation effects.

[0058] By rationally arranging the heat pipes in the concrete reinforcement grid, a certain distance is maintained between the heat pipes and the reinforcement to avoid affecting the performance of the reinforcement and concrete pouring.

[0059] By using liquid filling and vacuum sealing components on the top of the heat pipe, the heat pipe is filled with liquid, vacuumed and sealed.

[0060] It can be carried out on site and heat pipes can be quickly manufactured using ordinary pipe fittings, which greatly reduces the manufacturing cost of heat pipes and improves the application flexibility of heat pipes. It can also solve the problem of disposable packaged heat pipes being scrapped due to failure.

[0061] Timely leak detection, fluid replacement, and vacuum restoration extend the heat pipe's design life. The head uses a two-stage sealing mechanism. The inner spring seal assembly can be used for long-term standby and negative pressure sealing during low-temperature operation. The outer threaded cap ensures the heat pipe's airtightness during both vacuum and high-pressure operation.

[0062] The device described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the scope of the technical innovation of the present invention.

Claims

1. A containment dome heat exchange device, characterized in that: include: A heat pipe, a base and a steel lining, wherein the heat pipes are multiple in number, and there are intervals between the multiple heat pipes, and the multiple heat pipes are arranged in the dome concrete, and the multiple heat pipes all extend out of the dome concrete to form a condensation section; The base is provided at an end of the heat pipe away from the condensing section, and the heat pipe is connected to the steel lining via the base. The base is conical, which can ensure the stability of the heat pipe when installed on the steel lining before concrete pouring, and can also expand the contact area between the evaporation section of the heat pipe and the steel lining, thereby reducing the heat transfer resistance. A heat exchange rib is provided on the end of the steel lining away from the condensing section, and a first fin is provided on the heat exchange rib. The condensing section is provided with a second fin. The heat pipe includes an inner shell and a sleeve, the sleeve is arranged in the dome concrete and connected to the steel lining, the inner shell is exposed outside the dome concrete, and the inner shell is also connected to the lightning protection system; When the temperature inside the dome is higher than the outdoor temperature, the heat inside the dome is transferred to the condensation section for heat dissipation through the part of the heat pipe located in the dome concrete and the steel lining. At the same time, a natural convection circulation will be formed in the dome. By mixing the cold air in the dome with the hot air below, the temperature gradient in the upper space of the containment is effectively reduced, the environmental conditions of the concrete and process equipment are improved, and hydrogen accumulation can be alleviated after an accident.

2. The containment dome heat exchange device according to claim 1, characterized in that: A waterproof seal is provided between the condensation section and the dome concrete.

3. The containment dome heat exchange device according to claim 1, characterized in that: The inner shell is threadedly connected to the sleeve.

4. The containment dome heat exchange device according to claim 1, characterized in that: The inner shell and the sleeve are integrally formed, and a head is provided at one end of the inner shell away from the sleeve, so that the heat pipe can be injected with liquid, vacuumed and repaired on site through the head.

5. A containment dome heat exchange device according to any one of claims 3 to 4, characterized in that: The second fin is arranged on the inner shell.

6. The containment dome heat exchange device according to claim 4, characterized in that: A limited cavity is provided on the sealing head, a sealing port and a card interface penetrating the limited cavity are provided on the limiting cavity, the sealing port is located at one end close to the inner shell, the card interface is located at a side opposite to the sealing port, a sealing cover is provided on the end of the sealing head close to the card interface, the sealing cover is connected to the sealing head to close the card interface; a sealing assembly is provided in the limiting cavity, the sealing assembly includes a sealing block, a card member and a spring, one end of the card member is connected to the sealing block via the spring, and a side of the sealing block away from the spring is used to close or open the sealing port; In which, the card component is adapted to the shape of the card interface so that the card component can be moved out of the limiting cavity from the sealing port or intercepted by the card interface in the limiting cavity by rotating the card component, and when the card component is intercepted at the card interface, the spring is in a compressed state.

7. The containment dome heat exchange device according to claim 6, characterized in that: The sealing assembly further comprises a sealing gasket, which is arranged on a surface of the sealing block away from the spring, so as to close or open the sealing port through the sealing gasket.

8. The containment dome heat exchange device according to claim 6, characterized in that: The sealing cover is threadedly connected to the sealing head.

9. The containment dome heat exchange device according to claim 6, characterized in that: Sealant is provided at the connection between the sealing cover and the sealing head.

Images