A method of fire protection for a ventilation system of a radioactive site

Abstract

This invention relates to the field of industrial ventilation technology and discloses a fire prevention method for ventilation systems in radioactive areas. The method includes the following steps: under normal conditions, all fire dampers on the intake and exhaust ducts remain open; in the event of a fire, the fire dampers on all intake ducts corresponding to the room in the radioactive zone where the fire occurred are closed; the temperature at the inlet of the final exhaust filter on the exhaust duct is monitored; when the temperature reaches the set operating temperature of the final exhaust filter, the fire dampers on all exhaust ducts corresponding to the room in the radioactive zone where the fire occurred are closed; after the fire is extinguished, the fire dampers on all intake and exhaust ducts corresponding to the room in the radioactive zone where the fire occurred are reopened. This invention solves the problem that ventilation systems in industrial buildings cannot prioritize the control of radioactive materials during a fire, thereby preventing the long-term pollution and harm to the environment caused by the spread of radioactive materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial ventilation, in particular to a fireproof method for a ventilation system of a radioactive site. BACKGROUND

[0002] Industrial ventilation technology refers to a building environment control technology for controlling the spread and harm of air pollutants by means of air exchange dilution or ventilation removal, so as to realize indoor and outdoor air environment quality guarantee. The ventilation system refers to a complete set of devices for realizing the function of ventilation, including air inlet pipeline, air outlet pipeline, fan, filter, controller and other auxiliary equipment. According to the relevant provisions of the Code for Fire Protection Design of Buildings, the ventilation system should take fireproof measures, so as to guarantee the safety of persons and property in the event of and after a fire.

[0003] In the related art, the main function to be realized by the ventilation system of a general industrial building in the design process is to control fire smoke. The method for controlling fire smoke includes smoke exhaust and pressurized smoke prevention. The smoke exhaust mainly makes the indoor and outdoor communicate and provides a stable air flow channel to exhaust the smoke. The pressurized smoke prevention reverses the fan to pressurize the room at the safety passage to prevent the smoke from entering the designated area.

[0004] According to the above related art, the inventors believe that in a place where radioactive substances exist, for example, a nuclear fuel reprocessing plant, when a fire occurs, the main function of the ventilation system must be to prioritize the control of radioactive substances to prevent the spread of radioactive substances and cause long-term pollution and harm to the environment. Therefore, there is an urgent need for a fireproof method for a ventilation system of a radioactive site. SUMMARY

[0005] Therefore, the present application provides a fireproof method for a ventilation system of a radioactive site, which solves the problem that the ventilation system of an industrial building cannot prioritize the control of radioactive substances when a fire occurs to prevent the spread of radioactive substances and cause long-term pollution and harm to the environment.

[0006] The present application provides a fireproof method for a ventilation system of a radioactive site, comprising the following steps:

[0007] The air inlet pipe and the air exhaust pipe are communicated with the corresponding radioactive area room, the air inlet pipe is provided with an air inlet fireproof valve, the air exhaust pipe is provided with an air exhaust fireproof valve, the air exhaust pipe is sequentially communicated with a front air exhaust filter group and a final air exhaust filter group, and the air exhaust pipe is also communicated with an air exhaust fan; the air inlet fireproof valve and the air exhaust fireproof valve are kept open in a normal state, when a fire occurs, all the air inlet fireproof valves corresponding to the radioactive area room where the fire occurs are closed to keep the negative pressure of the radioactive area room; the temperature of the air exhaust pipe at the air inlet of the final air exhaust filter group is monitored, when the temperature reaches the set working temperature of the final air exhaust filter group, all the air exhaust fireproof valves corresponding to the radioactive area room where the fire occurs are closed; after waiting for the fire to be extinguished, all the air inlet fireproof valves and all the air exhaust fireproof valves corresponding to the radioactive area room where the fire occurs are opened again.

[0008] Beneficial effects: when a fire occurs, the air inlet fireproof valve is closed, at this time, the air exhaust fireproof valve keeps working, the air in the radioactive area room is continuously exhausted, the negative pressure in the radioactive area room is kept, so that the air in the radioactive area room which may carry radioactive substances is prevented from being discharged to the surrounding area, at the same time, the temperature of the air inlet of the final air exhaust filter group is monitored in real time, the final air exhaust filter is prevented from being disabled due to the working temperature exceeding the set working temperature, so that the air exhausted in the air exhaust pipe is always filtered before being discharged to the outside, and the possibility of radioactive substances diffusing to the outside environment and causing long-term pollution and harm to the environment is prevented.

[0009] In an optional embodiment, the air inlet fireproof valves are electrically connected with the fire alarms of the corresponding radioactive area rooms, and the air inlet fireproof valves are automatically closed when receiving the alarm signals of the fire alarms.

[0010] Beneficial effects: through the linkage of the air inlet fireproof valve and the fire alarm of the corresponding radioactive area room, the response speed of the air inlet fireproof valve closing is faster, and the possibility of radioactive substances being released to the surrounding environment due to the air pressure rising in the radioactive area room caused by the fire is greatly reduced.

[0011] In an optional embodiment, the front air exhaust filter group comprises at least one air exhaust filter, when the front air exhaust filter group comprises a plurality of air exhaust filters, the plurality of air exhaust filters are arranged in parallel through pipes.

[0012] Beneficial effects: the plurality of air exhaust filters in parallel in the same front air exhaust filter group, according to the required filtering process, the number of air exhaust filters in parallel in the front air exhaust filter is determined, the air exhaust filters can be standby for each other, the ventilation system can be applied to more application places, and the practicability is improved.

[0013] In an alternative embodiment, the pre-exhaustion filter group is arranged in a separate closed room outside the radioactive area room.

[0014] Beneficial effects: Since the pre-exhaustion filter group is close to the fire source on the exhaust pipe, the working temperature of the pre-exhaustion filter group rises rapidly when a fire occurs, which may cause the filter efficiency to decrease or the pre-exhaustion filter to be damaged. Arranging the pre-exhaustion filter in a separate closed room reduces the possibility of the pre-exhaustion filter group being directly contacted by fire and reduces the contamination range of radioactive substances when the pre-exhaustion filter group is damaged and leaks.

[0015] In an alternative embodiment, each exhaust filter in the pre-exhaustion filter group is a fire-resistant filter.

[0016] Beneficial effects: By using fire-resistant filters, the effective working time of the pre-exhaustion filter group is prolonged when a fire occurs, the possibility of the pre-exhaustion filter efficiency decreasing or being damaged is reduced, and the reliability of the ventilation system is improved.

[0017] In an alternative embodiment, the exhaust fireproof valve is located between the pre-exhaustion filter group and the final exhaust filter group on the exhaust pipe.

[0018] Beneficial effects: Since the national standards of the related art require the use of fireproof valves with a fuse protection function, i.e., the fireproof valve automatically closes when the temperature exceeds the set temperature, arranging the exhaust fireproof valve on the side of the pre-exhaustion filter away from the fire site delays the triggering of the fuse protection function, thereby prolonging the air filtration time of the ventilation system after a fire occurs and reducing the diffusion of radioactive substances.

[0019] In an alternative embodiment, the final exhaust filter group includes at least one exhaust filter, and when the final exhaust filter group includes multiple exhaust filters, the exhaust filters are arranged in parallel with each other through pipes.

[0020] Beneficial effects: Parallelly arranging multiple final exhaust filters can increase the upper limit of the air flow that the ventilation system can filter, and increasing or decreasing the number of exhaust filters in the final exhaust filter group according to needs can make the ventilation system applicable to more places and improve the practicality.

[0021] In an alternative embodiment, the exhaust pipe includes a main pipe and a plurality of branch pipes connected to the main pipe, the plurality of branch pipes are respectively in communication with corresponding radioactive area rooms, the pre-exhaustion filter group is arranged in a plurality of groups, the plurality of groups of pre-exhaustion filter groups are respectively in one-to-one correspondence with the plurality of branch pipes and are in communication in the pipelines of the corresponding branch pipes, and the final exhaust filter group is in communication in the pipeline of the main pipe.

[0022] Beneficial effects: The exhaust pipe is arranged as a pipe combined with a main pipe and branch pipes, and a pre-exhaust filter group is arranged at each branch pipe, the branch pipes are connected to different radioactive area rooms and air in all the radioactive area rooms is introduced into the main pipe, and the air is uniformly filtered by the final exhaust filter, so that one set of ventilation system can serve more radioactive area rooms, and the application range is improved.

[0023] In an alternative embodiment, the exhaust fireproof valves are arranged in one-to-one correspondence with the branch pipes and are arranged on the corresponding branch pipes.

[0024] Beneficial effects: By arranging multiple exhaust fireproof valves to control the branch pipes of different radioactive area rooms, the exhaust fireproof valves of specified radioactive area rooms can be flexibly closed, and the ventilation system of the remaining rooms can still work normally when a fire occurs in a room.

[0025] In an alternative embodiment, the exhaust fan is arranged on the main pipe on the side away from the pre-exhaust filter group.

[0026] Beneficial effects: The exhaust fan is arranged at the end of the entire ventilation system, reducing the possibility of the exhaust fan being affected by fire, and the air has been sufficiently filtered when reaching the exhaust fan, so that the protection level of the staff is lower when repairing and replacing the exhaust fan, and the operation is more convenient and fast. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0028] Figure 1 A schematic diagram of a ventilation system used for a fireproof method for a ventilation system in a radioactive place according to an embodiment of the present application;

[0029] Figure 2 A flowchart of a fireproof method for a ventilation system in a radioactive place according to an embodiment of the present application.

[0030] Explanation of reference signs:

[0031] 1, air inlet pipe; 2, exhaust pipe; 201, main pipe; 202, branch pipe; 3, air inlet fireproof valve; 4, exhaust fireproof valve; 5, pre-exhaust filter group; 6, final exhaust filter group; 7, exhaust fan; 8, air volume regulating valve. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0033] The embodiments of the present application are described below with reference to the accompanying drawings. Figure 1 and Figure 2

[0034] According to the embodiments of the present application, a fireproof method for a ventilation system of a radioactive site is provided, comprising the following steps: an air inlet pipe 1 and an air outlet pipe 2 are communicated with corresponding radioactive area rooms, an air inlet fireproof valve 3 is arranged on the air inlet pipe 1, an air outlet fireproof valve 4 is arranged on the air outlet pipe 2, a pre-outlet filter group 5 and a final-stage outlet filter group 6 are sequentially communicated on the air outlet pipe 2, and an air outlet fan 7 is further communicated on the air outlet pipe 2.

[0035] In a normal state, the air inlet fireproof valve 3 and the air outlet fireproof valve 4 are kept open, and a staff adjusts a plurality of air volume adjusting valves 8 arranged in the air inlet pipe 1 and the air outlet pipe 2 to adjust the air pressure in the radioactive area rooms to keep a negative pressure, and when a fire occurs, all the air inlet fireproof valves 3 corresponding to the radioactive area rooms where the fire occurs are closed to keep the negative pressure of the radioactive area rooms.

[0036] When the air inlet fireproof valves 3 are closed, the staff monitors the temperature at the air inlet of the final-stage outlet filter group 6 in the air outlet pipe 2, and when the temperature reaches a set working temperature of the final-stage outlet filter group 6, all the air outlet fireproof valves 4 corresponding to the radioactive area rooms where the fire occurs are closed, and the set working temperature is determined by the staff according to the type of the used outlet filter.

[0037] After waiting for the fire to be extinguished, all the air inlet fireproof valves 3 and all the air outlet fireproof valves 4 corresponding to the radioactive area rooms where the fire occurs are reopened.

[0038] When a fire occurs, the air inlet fireproof valves 3 of the radioactive area rooms where the fire occurs are closed, at this time, the air outlet fireproof valves 4 are kept open, and the air outlet fan 7 is kept in a working state to continuously draw air out of the radioactive site rooms, so as to forcibly keep the negative pressure state in the rooms and prevent the air containing radioactive substances from leaking from the radioactive area.

[0039] ​When the air inlet fireproof valve 3 is closed, the staff detects the temperature at the air inlet of the last-stage exhaust filter group 6 in real time. When the temperature rises to the set temperature of the last-stage exhaust filter group 6, the staff manually or remotely closes the exhaust fireproof valve 4 corresponding to the radioactive area room where the fire occurs, thereby preventing the temperature at the last-stage exhaust filter from rising further and causing damage to the last-stage exhaust filter, and preventing a large amount of air carrying radioactive substances from being discharged into the external environment due to the failure of the last-stage exhaust filter, causing long-term pollution and harm.

[0040] In one embodiment, the air inlet fireproof valve 3 is electrically connected to the fire alarm of the radioactive area room corresponding to the air inlet pipe 1. When the air inlet fireproof valve 3 receives an alarm signal from the fire alarm, the air inlet fireproof valve 3 automatically closes, thereby improving the response speed of the air inlet fireproof valve 3 closing and reducing the influence of the air pressure rise in the radioactive area room due to the occurrence of fire on the dynamic sealing effect of the radioactive area room.

[0041] In one embodiment, the pre-exhaust filter group 5 includes at least one exhaust filter. When the number of exhaust filters is greater than one, the exhaust filters in the same pre-exhaust filter group 5 are connected in parallel through a pipeline. The number of parallel exhaust filters in the same pre-exhaust filter group is determined according to the required filtering process. The exhaust filters can be standby for each other, which can make the ventilation system applicable to more application places and improve the practicality.

[0042] In one embodiment, the pre-exhaust filter group 5 is arranged in a separate closed room outside the radioactive area room. On the one hand, the pre-exhaust filter group 5 is isolated from the fire scene to avoid direct influence of the fire scene on the pre-exhaust filter group 5. On the other hand, since the pre-exhaust filter is closer to the fire scene on the pipeline of the exhaust pipe 2 and the working temperature rises quickly, arranging the pre-exhaust filter in a separate closed room can reduce the diffusion of radioactive substances when the pre-exhaust filter efficiency decreases or the pre-exhaust filter is damaged.

[0043] In one embodiment, each exhaust filter in the pre-exhaust filter group 5 is a fire-resistant filter, which effectively increases the continuous working time of the pre-exhaust filter group 5 when a fire occurs, improves the reliability of air filtration of the ventilation system, and reduces the possibility of air diffusion carrying radioactive substances due to the decrease in pre-exhaust filter efficiency or the damage of pre-exhaust filter.

[0044] In one embodiment, the exhaust fireproof valve 4 is located on the exhaust pipe 2 pipeline between the pre-exhaust filter group 5 and the final exhaust filter group 6. Since the fireproof valve required by the national standard of the related technology has a fuse protection function, that is, the fireproof valve will automatically close when the temperature exceeds the fuse setting temperature. By setting the exhaust fireproof valve 4 on the exhaust pipe 2 pipeline away from the pre-exhaust filter on the side of the fire scene, the time for triggering the fuse protection function is delayed, thereby prolonging the time of the ventilation system filtering air after a fire occurs, and thereby reducing the diffusion of radioactive substances.

[0045] In one embodiment, the final exhaust filter group 6 includes at least one exhaust filter. When the final exhaust filter group 6 includes multiple exhaust filters, each exhaust filter is connected in parallel through a pipeline in the pipeline of the exhaust pipe 2. The parallel arrangement of multiple final exhaust filters can increase the upper limit of the air flow that the ventilation system can filter. According to the need, the number of exhaust filters of the final exhaust filter group 6 can be increased or decreased to make the ventilation system applicable to more places and improve the practicality.

[0046] In one embodiment, the exhaust pipe 2 includes a main pipe 201 and a plurality of branch pipes 202 connected to the main pipe 201. The plurality of branch pipes 202 are respectively communicated with the corresponding radioactive area rooms. The pre-exhaust filter group 5 is provided with a plurality of groups, and the plurality of pre-exhaust filter groups 5 are respectively communicated with the plurality of branch pipes 202 in the pipeline of the corresponding branch pipes 202. The final exhaust filter group 6 is communicated in the pipeline of the main pipe 201. When the ventilation system serves multiple radioactive area rooms, the air in each radioactive area room is filtered through different branch pipes 202 and different radioactive area rooms, and then the air from each radioactive area room is collected by the main pipe 201 to the final exhaust filter for unified filtering. One set of ventilation system can serve more radioactive area rooms, thereby improving the application range.

[0047] In one embodiment, the exhaust fireproof valve 4 is provided with a plurality of exhaust fireproof valves 4, and the plurality of exhaust fireproof valves 4 are respectively arranged on the corresponding branch pipes 202. The plurality of exhaust fireproof valves 4 control the different branch pipes 202, which can more flexibly close the exhaust pipe 2 of the specified radioactive area room. When a fire occurs in a certain room, the ventilation system of the remaining rooms can still work normally.

[0048] In one embodiment, the exhaust fan 7 is arranged on the pipeline of the main pipe 201 at the side of the last-stage exhaust filter group 6 away from the preposed exhaust filter group 5, so that the exhaust fan 7 is located at the end of the pipeline of the entire ventilation system, the possibility of the exhaust fan 7 being affected by fire is reduced, the air has been sufficiently filtered when reaching the exhaust fan 7, the protection level of the staff is lower when repairing and replacing the exhaust fan 7, and the operation is more convenient and fast.

[0049] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A fire prevention method for a ventilation system in a radioactive site, characterized in that, Includes the following steps: Both the air inlet pipe (1) and the air outlet pipe (2) are connected to the corresponding radioactive area room. The air inlet pipe (1) is equipped with an air inlet fire damper (3), and the air outlet pipe (2) is equipped with an air outlet fire damper (4). The air outlet pipe (2) is connected in sequence to a pre-exhaust air filter group (5) and a final exhaust air filter group (6). The air outlet pipe (2) is also connected to an exhaust fan (7). Under normal conditions, the air intake fire damper (3) and the air exhaust fire damper (4) remain open. When a fire occurs, all the air intake fire dampers (3) corresponding to the room in the radioactive area where the fire occurred are closed to maintain the negative pressure in the room in the radioactive area. The temperature of the exhaust pipe (2) at the air inlet of the final exhaust filter group (6) is monitored. When the temperature reaches the set working temperature of the final exhaust filter group (6), all the exhaust fire dampers (4) corresponding to the room in the radioactive area where the fire occurred are closed. After the fire is extinguished, reopen all the air intake fire dampers (3) and all the exhaust fire dampers (4) corresponding to the room in the radioactive area where the fire occurred.

2. A fire prevention method for a ventilation system in a radioactive site according to claim 1, characterized in that, The air intake fire dampers (3) are all electrically connected to the fire alarms of the corresponding radioactive areas. When the air intake fire dampers (3) receive the alarm signal from the fire alarm, they automatically close.

3. A fire prevention method for a ventilation system in a radioactive site according to claim 1, characterized in that, The pre-exhaust filter group (5) includes at least one exhaust filter. When the pre-exhaust filter group (5) includes multiple exhaust filters, the multiple exhaust filters are connected in parallel through pipes.

4. A fire prevention method for a ventilation system in a radioactive site according to claim 3, characterized in that, The pre-exhaust air filter group (5) is installed in a separate, enclosed room outside the room in the radioactive area.

5. A fire prevention method for a ventilation system in a radioactive site according to claim 3, characterized in that, Each exhaust filter in the pre-exhaust filter group (5) is a fire-resistant filter.

6. A fire prevention method for a ventilation system in a radioactive site according to claim 5, characterized in that, The exhaust fire damper (4) is located between the pre-exhaust filter group (5) and the final exhaust filter group (6) on the exhaust pipe (2).

7. A fire prevention method for a ventilation system in a radioactive site according to claim 5, characterized in that, The final exhaust filter group (6) includes at least one exhaust filter. When the final exhaust filter group (6) includes multiple exhaust filters, the exhaust filters are connected in parallel to each other through pipes.

8. A fire prevention method for a ventilation system in a radioactive site according to claim 5, characterized in that, The exhaust duct (2) includes a main duct (201) and several branch ducts (202) connected to the main duct (201). The several branch ducts (202) are respectively connected to the corresponding radioactive area rooms. The pre-exhaust filter group (5) is provided in several groups. The several groups of pre-exhaust filter groups (5) correspond one-to-one with the several branch ducts (202) and are connected in the pipeline of the corresponding branch duct (202). The final exhaust filter group (6) is connected in the pipeline of the main duct (201).

9. A fire prevention method for a ventilation system in a radioactive site according to claim 8, characterized in that, The exhaust fire damper (4) is provided in several units, and each exhaust fire damper (4) corresponds to a branch pipe (202) and is installed on the corresponding branch pipe (202).

10. A fire prevention method for a ventilation system in a radioactive site according to claim 8, characterized in that, The exhaust fan (7) is located on the main pipe (201) on the side away from the pre-exhaust filter group (5) of the final exhaust filter group (6).

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