Containment building vestibule ventilation system

Abstract

The utility model provides a kind of safety shell ring corridor's ventilation system, the safety shell ring corridor's ventilation system includes the first exhaust system, second exhaust system and third exhaust system for gas flow of safety shell ring corridor and safety shell outside. Among them, first exhaust system is set in first fire compartment, second exhaust system is set in second fire compartment, and first fire compartment and second fire compartment are physically separated. By designing two independent and mutually redundant first exhaust system and second exhaust system, for accident condition, collect the gas leakage from inner layer safety shell to safety shell ring corridor and the gas flow in safety shell ring corridor from outer layer safety shell, to reduce the radioactive gas leakage amount in safety shell ring corridor as far as possible, ensure the working stability of entire ventilation system. While third exhaust system maintains the negative pressure in safety shell ring corridor not less than design reference under normal condition.

Description

Technical Field

[0001] This utility model relates to the field of safety facilities technology for nuclear reactors, and specifically to a ventilation system for a containment corridor. Background Technology

[0002] The design and operation of the containment ventilation system are crucial for the safe operation of nuclear power plants. It not only maintains a suitable working environment during normal containment operation but also plays a key role in ensuring the effective control of radioactive material release during accident conditions. Currently, some operating nuclear power plants have a single-layer containment design. Existing containment ventilation systems typically consist of only one normal exhaust subsystem and one iodine filtration exhaust system. However, in existing ventilation systems, one exhaust fan from the normal exhaust system and two fans from the iodine filtration exhaust system are located in the same compartment. During accident conditions, the main equipment of the iodine filtration exhaust system cannot be physically isolated from the main equipment of the normal exhaust system, resulting in low system safety, poor dynamic containment of radioactive materials, and difficulty in assessing the containment effect. Utility Model Content

[0003] In view of the technical problems of the existing ventilation system being not safe and having poor dynamic containment effect of radioactive materials, this utility model provides a ventilation system for the containment corridor.

[0004] To achieve the above and other related objectives, this utility model provides a ventilation system for a containment corridor, comprising a first exhaust system, a second exhaust system, and a third exhaust system. The inlet duct of the first exhaust system is connected to the containment corridor, and the outlet duct of the first exhaust system is connected to a chimney. The inlet duct of the second exhaust system is connected to the containment corridor, and the outlet duct of the second exhaust system is connected to the chimney. The inlet duct of the third exhaust system is connected to the containment corridor, and the outlet duct of the third exhaust system is connected to the chimney. The first exhaust system is located in a first fire compartment, the second exhaust system is located in a second fire compartment, and the first fire compartment and the second fire compartment are physically separated.

[0005] In one embodiment of the ventilation system of this utility model, the first exhaust system and the second exhaust system are configured the same.

[0006] In one embodiment of the ventilation system of this utility model, the second exhaust system includes a second isolation valve, a second electric heater, a second filter assembly, a second adsorber, a second exhaust fan, and a second check valve connected in sequence by pipes. The inlet pipe of the second isolation valve is connected to the containment corridor, and the outlet pipe of the second check valve is connected to the chimney.

[0007] In one embodiment of the ventilation system of this utility model, the second exhaust system further includes a second bypass regulating valve, the air inlet pipe of the second bypass regulating valve is connected to the air outlet of the second adsorber, and the air outlet pipe of the second bypass regulating valve is connected to the air inlet of the second check valve.

[0008] In one embodiment of the ventilation system of this utility model, the second isolation valve is an electric isolation valve.

[0009] In one embodiment of the ventilation system of this utility model, the second filter assembly includes a second pre-filter and a second HEPA filter connected in series.

[0010] In one embodiment of the ventilation system of this utility model, the second adsorber is an iodine adsorber.

[0011] In one embodiment of the ventilation system of this utility model, the air inlet of the third exhaust system is connected to the air outlet pipe of the second isolation valve, and the air outlet of the third exhaust system is connected to the air outlet pipe of the second check valve.

[0012] In one embodiment of the ventilation system of this utility model, the third exhaust system includes a third isolation valve, a third filter assembly, a third exhaust fan, and a third check valve connected in sequence by pipes. The air inlet pipe of the third isolation valve is connected to the air outlet pipe of the second isolation valve, and the air outlet pipe of the third check valve is connected to the air outlet pipe of the second check valve.

[0013] In one embodiment of the ventilation system of this utility model, the third exhaust system further includes a third bypass regulating valve, the air inlet pipe of the third bypass regulating valve is connected to the air outlet of the third HEPA filter, and the air outlet pipe of the third bypass regulating valve is connected to the air outlet of the third check valve.

[0014] In one embodiment of the ventilation system of this utility model, there are two sets of third isolation valves, and the two sets of third isolation valves are connected in series.

[0015] In one embodiment of the ventilation system of this utility model, the third exhaust system is located in the second fire compartment.

[0016] This invention provides a ventilation system for a containment corridor. The system incorporates two independent and redundant exhaust systems (first and second) to collect gas leaks from both the inner and outer containment layers into the corridor during accident conditions. This ensures that at least one exhaust system is operational during an accident, minimizing radioactive gas leakage within the corridor. Simultaneously, a third exhaust system maintains a negative pressure within the corridor above the design baseline under normal operating conditions. These three exhaust systems guarantee the ventilation system's ability to regulate negative pressure within the containment corridor under any conditions, thus better enabling the dynamic containment of radioactive materials. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a ventilation system according to one embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of part of the exhaust system in one embodiment of the ventilation system of this utility model. Figure 1 ;

[0020] Figure 3 This is a schematic diagram of part of the exhaust system in one embodiment of the ventilation system of this utility model. Figure 2 .

[0021] Component designation explanation:

[0022] 1. First exhaust system; 11. First isolation valve; 12. First electric heater; 13. First pre-filter; 14. First HEPA filter; 15. First adsorber; 16. First exhaust fan; 17. First check valve; 18. First bypass regulating valve; 2. Second exhaust system; 21. Second isolation valve; 22. Second electric heater; 23. Second pre-filter; 24. Second HEPA filter; 25. Second adsorber; 26. Second exhaust fan; 27. Second check valve; 28. Second bypass regulating valve; 3. Third exhaust system; 31. Third isolation valve; 32. Third pre-filter; 33. Third HEPA filter; 34. Third exhaust fan; 35. Third check valve; 36. Third bypass regulating valve; 4. Containment corridor; 5. Chimney; 6. First fire compartment; 7. Second fire compartment. Detailed Implementation

[0023] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers.

[0024] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, equipment, and materials similar to or equivalent to those in the embodiments of this invention.

[0025] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0026] To address the technical problems of existing ventilation systems' low safety and poor dynamic containment of radioactive materials, this invention provides a ventilation system for a containment annulus. This ventilation system ensures that the negative pressure within the containment annulus remains above the design baseline during normal operation or accident conditions, guaranteeing the ability to regulate the negative pressure within the containment annulus and reducing the leakage of radioactive gases.

[0027] Please see Figures 1 to 3This invention provides a ventilation system for a containment corridor. This system is used to maintain a suitable working environment during normal containment operation and to control radioactive materials under accident conditions. The ventilation system is suitable for third-generation nuclear power plants with a double-sided containment design. The space between the inner and outer containment layers is the containment corridor. This ventilation system maintains negative pressure in the containment corridor, limiting the release of radioactive materials into the outdoor environment. The ventilation system includes a first exhaust system 1, a second exhaust system 2, and a third exhaust system 3. The first exhaust system 1 is used to handle the release of radioactive gases from the containment corridor 4 to the outside of the containment under accident conditions and to maintain negative pressure in the containment corridor 4. The inlet duct of the first exhaust system 1 is connected to the containment corridor 4, and the outlet duct of the first exhaust system 1 is connected to the chimney 5.

[0028] The first exhaust system 1 and the second exhaust system 2 are redundant. They have the same function: to handle the release of radioactive gases from the containment annulus 4 to the outside of the containment under accident conditions, and to maintain the negative pressure in the containment annulus 4. The first exhaust system 1 and the second exhaust system 2 can be configured identically or differently, as long as they can guarantee the handling capacity under accident conditions. The inlet duct of the second exhaust system 2 is connected to the containment annulus 4, and the exhaust duct of the second exhaust system 2 is connected to the chimney 5.

[0029] The third exhaust system 3 is used to maintain the negative pressure in the containment corridor 4 and the airflow between the containment and the outside of the containment under normal operating conditions. The inlet pipe of the third exhaust system 3 is connected to the containment corridor 4, and the exhaust pipe of the third exhaust system 3 is connected to the chimney 5. The inlet of the third exhaust system 3 can be directly connected to the containment corridor 4 through a pipeline, or it can be connected to the containment corridor 4 through a pipeline shared with the first exhaust system 1 or the second exhaust system 2, without limitation.

[0030] The first exhaust system 1 is located in the first fire compartment 6, and the second exhaust system 2 is located in the second fire compartment 7, with the first fire compartment 6 and the second fire compartment 7 physically separated. This physical separation, the redundant design of the first exhaust system 1 and the second exhaust system 2, and their independent operation ensure that if some equipment in one system fails, the other system can still operate normally, improving the reliability of the entire ventilation system. This effectively reduces the risk of radioactive gas leakage and improves the safety of the nuclear power plant. The physical separation method for the first exhaust system 1 and the second exhaust system 2 is not limited; for example, physical isolation or spatial isolation can be used, but this is not a limitation. Specifically, in this embodiment, physical isolation is used, with firewalls and fire doors installed between the first fire compartment 6 and the second fire compartment 7 to ensure the independent operation of the first exhaust system 1 and the second exhaust system 2 and reduce the space occupied by the ventilation system.

[0031] The ventilation system of the containment corridor incorporates two independent and redundant exhaust systems, a first exhaust system 1 and a second exhaust system 2. When the containment is under accident conditions, at least one of these systems can collect gas leaks from the inner and outer containment layers into the containment corridor 4, ensuring normal operation of the exhaust system under accident conditions and minimizing radioactive gas leakage within the containment corridor 4. Simultaneously, under normal nuclear power plant operation, a third exhaust system 3 collects gas leaks from the outer containment layer into the containment corridor 4, maintaining the negative pressure within the containment corridor 4 at or above the design baseline. The third exhaust system 3, along with the first and second exhaust systems 1 and 2, ensures the entire ventilation system can regulate the negative pressure of the containment corridor 4 under any operating condition, better achieving dynamic containment of radioactive materials.

[0032] Please see Figure 1 and Figure 2 In one embodiment of the ventilation system of this utility model, the first exhaust system 1 and the second exhaust system 2 are configured identically, that is, the first exhaust system 1 and the second exhaust system 2 have the same structure and function. This redundant design makes the first exhaust system 1 and the second exhaust system 2 backups for each other, ensuring that when one system fails or is under maintenance, the other system can seamlessly take over, thereby improving the overall reliability of the system.

[0033] Please see Figure 1 and Figure 2 In one embodiment of the ventilation system of this utility model, the second exhaust system 2 includes a second isolation valve 21, a second electric heater 22, a second filter assembly, a second adsorber 25, a second exhaust fan 26, and a second check valve 27 connected in sequence by pipes. The air inlet pipe of the second isolation valve 21 is connected to the containment corridor 4, and the air outlet pipe of the second check valve 27 is connected to the chimney 5.

[0034] In one embodiment of the ventilation system of this utility model, the second filter assembly includes a second pre-filter 23 and a second HEPA filter 24 connected in series. The air inlet of the second pre-filter 23 is connected to the air outlet of the second electric heater 22, and the air outlet of the second HEPA filter 24 is connected to the air inlet of the second adsorber 25. The second filter assembly uses a combination of a pre-filter and a HEPA filter, which can achieve stratified filtration of exhaust gas, while extending the service life of the HEPA filter and reducing the replacement frequency, thus lowering operating costs.

[0035] In one embodiment of the ventilation system of this utility model, the second adsorber 25 is an iodine adsorber. The adsorption effect of the iodine adsorber removes radioactive iodine from the air, improves air purification efficiency, and reduces environmental pollution and personnel risks. Similarly, the first adsorber 15 also uses an iodine adsorber.

[0036] It should be noted that the main system equipment such as the isolation valve, electric heater, primary filter, HEPA filter, adsorber, exhaust fan, and check valve described in this embodiment and the following embodiments are widely used in the nuclear power industry. Their functions and structures are well known in the industry and can be obtained through general commercial means, so they will not be described in detail here. Similarly, the first exhaust system 1 includes a first isolation valve 11, a first electric heater 12, a first filter assembly, a first adsorber 15, a first exhaust fan 16, and a first check valve 17 connected in sequence by pipes. The air inlet pipe of the first isolation valve 11 is connected to the containment corridor 4, and the air outlet pipe of the first check valve 17 is connected to the chimney 5. The first filter assembly has the same configuration as the second filter assembly, and the first filter assembly includes a first primary filter 13 and a first HEPA filter 14 connected in series. Similarly, the configuration and function of the first exhaust system 1 are the same as those of the second exhaust system 2, so they will not be described in detail here.

[0037] Please see Figure 1 and Figure 2In one embodiment of the ventilation system of this utility model, the second exhaust system 2 further includes a second bypass regulating valve 28. The air inlet pipe of the second bypass regulating valve 28 is connected to the air outlet pipe of the second adsorber 25, and the air outlet pipe of the second bypass regulating valve 28 is connected to the air inlet pipe of the second check valve 27. Specifically, in this embodiment, the air inlet of the second bypass regulating valve 28 is connected to the exhaust pipe between the second adsorber 25 and the second exhaust fan 26 through a bypass pipe, and the air outlet of the second bypass regulating valve 28 is connected to the exhaust pipe between the second exhaust fan 26 and the second check valve 27 through a bypass pipe. The second bypass regulating valve 28 can be a manual regulating valve or an electric regulating valve. The second bypass regulating valve 28 is used to bypass part of the exhaust volume if the air volume or negative pressure of the containment corridor 4 is too high during the commissioning phase or the initial operation of the system, so as to improve the negative pressure regulation capability of the ventilation system. Similarly, since the first exhaust system 1 and the second exhaust system 2 have the same configuration, the first exhaust system 1 also includes a first bypass regulating valve 18. The connection relationship and function of the first bypass regulating valve 18 and the second bypass regulating valve 28 are similar, and will not be described again here.

[0038] In one embodiment of the ventilation system of this utility model, the second isolation valve 21 is an electrically operated isolation valve, and similarly, the first isolation valve 11 is an electrically operated isolation valve. The fact that both the first isolation valve 11 and the second isolation valve 21 are electrically operated isolation valves enables rapid on / off control of the exhaust air from the containment corridor 4 to the first exhaust system 1 or the second exhaust system 2, thereby improving the automatic control level and safety of the ventilation system.

[0039] Please see Figure 1 and Figure 3 In one embodiment of the ventilation system of this utility model, the air inlet of the third exhaust system 3 is connected to the air outlet of the second isolation valve 21, and the air outlet of the third exhaust system 3 is connected to the air outlet of the second check valve 27. Specifically, the air inlet of the third exhaust system 3 is directly connected to the exhaust duct between the second isolation valve 21 and the second electric heater 22. The second isolation valve 21 can control the airflow between the containment corridor 4 and the second exhaust system 2, and also control the airflow between the containment corridor 4 and the third exhaust system 3. The air outlet of the third exhaust system 3 is directly connected to the exhaust duct between the second check valve 27 and the chimney 5. The air inlet and outlet of the third exhaust system 3 can share part of the exhaust duct of the second exhaust system 2, reducing ductwork layout and lowering space occupation and cost.

[0040] Please see Figure 1 and Figure 3In one embodiment of the ventilation system of this utility model, the third exhaust system 3 includes a third isolation valve 31, a third filter assembly, a third exhaust fan 34, and a third check valve 35 connected in sequence by pipes. The air inlet pipe of the third isolation valve 31 is connected to the air outlet pipe of the second isolation valve 21, and the air outlet pipe of the third check valve 35 is connected to the air outlet pipe of the second check valve 27. At the same time, the air outlet pipe of the third check valve 35 is connected to the chimney 5. This ensures the exhaust ventilation from inside the containment corridor 4 to outside the containment under normal operating conditions and maintains the negative pressure reference inside the containment corridor 4.

[0041] The configuration of the third filter assembly is the same as that of the first and second filter assemblies. The third filter assembly includes a third pre-filter 32 and a third HEPA filter 33 connected in series by pipes. The air inlet pipe of the third pre-filter 32 is connected to the air outlet of the third isolation valve 31, and the air outlet pipe of the third HEPA filter 33 is connected to the air inlet of the third exhaust fan 34 to achieve exhaust filtration under normal operating conditions.

[0042] Please see Figure 1 and Figure 2 In one embodiment of the ventilation system of this utility model, the third exhaust system 3 further includes a third bypass regulating valve 36. The air inlet pipe of the third bypass regulating valve 36 is connected to the air outlet of the third HEPA filter 33, and the air outlet pipe of the third bypass regulating valve 36 is connected to the air outlet of the third check valve 35. The third bypass regulating valve 36 has a similar function to the second bypass regulating valve 28. Both are used to bypass part of the exhaust volume through the bypass pipe when the ventilation system is in the commissioning stage or the initial stage of system operation. This bypasses the exhaust pressure of the third exhaust fan 34, thereby improving the negative pressure regulation capability of the ventilation system.

[0043] Please see Figure 1 and Figure 2 In one embodiment of the ventilation system of this utility model, there are two sets of third isolation valves 31, which are connected in series. The third isolation valves 31 are electric check valves. The series redundancy design of the two sets of third isolation valves 31 ensures that the exhaust of the third exhaust system 3 is cut off in case of an accident, and ensures the smooth connection of the first exhaust system or the second exhaust system.

[0044] Please see Figure 1 In one embodiment of the ventilation system of this utility model, the third exhaust system 3 is located in the second fire compartment 7. The third exhaust system 3 shares the same fire compartment as the second exhaust system 2, which facilitates the unified management and maintenance of the equipment in the second exhaust system 2 and the third exhaust system 3. At the same time, it facilitates the sharing of some exhaust ducts between the second exhaust system 2 and the third exhaust system 3, simplifies the duct layout, and optimizes the space utilization of the entire ventilation system.

[0045] In the ventilation system of this invention, two independent and redundant first and second exhaust systems are designed to collect gas leaks from the inner containment structure to the containment corridor and from the outer containment structure to the containment corridor under accident conditions. This maintains the negative pressure within the containment corridor at a level not lower than the design baseline, ensuring that at least one exhaust system operates normally under accident conditions to minimize the amount of radioactive gas leaking from the containment corridor. Simultaneously, the third, first, and second exhaust systems ensure the ventilation system's ability to regulate the negative pressure within the containment corridor under any operating condition, better achieving dynamic containment of radioactive materials. This addresses the technical problems of existing ventilation systems having low system safety and poor dynamic containment of radioactive materials. Therefore, this invention effectively overcomes some practical problems in the prior art, thus possessing high utilization value and practical significance.

[0046] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A ventilation system for a containment corridor, characterized in that, include: The first exhaust ventilation system has an air inlet duct connected to the containment corridor and an exhaust duct connected to the chimney. The second exhaust system has an air inlet duct connected to the containment corridor and an exhaust duct connected to the chimney. The third exhaust ventilation system has an air inlet duct connected to the containment corridor and an exhaust duct connected to the chimney. The first exhaust system is located in the first fire compartment, the second exhaust system is located in the second fire compartment, and the first fire compartment and the second fire compartment are physically separated.

2. The ventilation system according to claim 1, characterized in that, The first exhaust system and the second exhaust system have the same configuration.

3. The ventilation system according to claim 1 or 2, characterized in that, The second exhaust system includes a second isolation valve, a second electric heater, a second filter assembly, a second adsorber, a second exhaust fan, and a second check valve connected in sequence by pipes; the air inlet pipe of the second isolation valve is connected to the containment corridor, and the air outlet pipe of the second check valve is connected to the chimney.

4. The ventilation system according to claim 3, characterized in that, The second exhaust system also includes a second bypass regulating valve, the air inlet pipe of which is connected to the air outlet of the second adsorber, and the air outlet pipe of which is connected to the air inlet of the second check valve.

5. The ventilation system according to claim 3, characterized in that, The second isolation valve is an electrically operated isolation valve.

6. The ventilation system according to claim 3, characterized in that, The second filter assembly includes a second pre-filter and a second HEPA filter connected in series.

7. The ventilation system according to claim 3, characterized in that, The second adsorber is an iodine adsorber.

8. The ventilation system according to claim 3, characterized in that, The air inlet of the third exhaust system is connected to the air outlet of the second isolation valve; the air outlet of the third exhaust system is connected to the air outlet of the second check valve.

9. The ventilation system according to claim 8, characterized in that, The third exhaust system includes a third isolation valve, a third filter assembly, a third exhaust fan, and a third check valve connected in sequence by pipes; the air inlet pipe of the third isolation valve is connected to the air outlet pipe of the second isolation valve; the air outlet pipe of the third check valve is connected to the air outlet pipe of the second check valve.

10. The ventilation system according to claim 9, characterized in that, The third exhaust system also includes a third bypass regulating valve, the air inlet pipe of which is connected to the air outlet of the third HEPA filter, and the air outlet pipe of which is connected to the air outlet of the third check valve.

11. The ventilation system according to claim 9, characterized in that, The number of the third isolation valves is two sets, and the two sets of the third isolation valves are connected in series.

12. The ventilation system according to claim 1, characterized in that, The third exhaust ventilation system is located in the second fire compartment.

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