Ventilation system for resident area of nuclear power plant

Abstract

A ventilation system for a resident area of a nuclear power plant comprises an air purification unit, an air outlet end is arranged at one end of the air purification unit, and an air outlet pipe with a certain length is arranged at the air outlet end; the air conditioning unit comprises an air inlet and an air outlet; the circulating pipeline comprises a circulating air return pipeline and an air supply pipeline, one end of the circulating air return pipeline is connected with an air outlet pipe of the air purification unit, and the other end of the circulating air return pipeline is connected with an air inlet of the air conditioning unit; the air conditioning unit and the circulating pipeline are arranged in the resident area, and the air purifying unit is arranged outside the resident area. According to the invention, zero internal leakage of non-filtered air in the resident area of the nuclear power plant is facilitated.

Description

Technical Field

[0001] The invention relates to ventilation technology for nuclear power plants, and in particular to a ventilation system for habitable areas of nuclear power plants. Background Art

[0002] The habitable area of ​​a nuclear power plant refers to the space where personnel live in the main control room of a nuclear power plant. The habitability of personnel must be guaranteed in this space. The most critical parameter affecting the habitability of the main control room is the amount of unfiltered air leakage into the main control room under accident conditions. The U.S. Nuclear Regulatory Commission has been paying attention to the habitability of the main control room of nuclear power plants under severe accident conditions since the 1980s. In the 1990s, it stipulated that all nuclear power plants must conduct tracer measurement tests of leakage in the main control room in accordance with relevant standards. The test results confirmed that the range of unfiltered air leakage in the main control room of the second-generation nuclear power plant is 0-7300m 3 / h, this unfiltered air will seriously affect the safety of the main control room personnel under accident conditions and their control capabilities over the nuclear reactor.

[0003] Although the unfiltered air leakage in the main control room of my country's third-generation nuclear power plants is controlled within the range of the design acceptance standard (less than 130m 3 / h), but there is still a certain amount of unfiltered air leakage. After entering the main control room of a nuclear power plant, this unfiltered radioactive contaminated air may still cause certain radiation hazards to the operators in the main control room, affecting their ability to control the nuclear reactor under accident conditions, thereby causing potential and immeasurable harm to professional personnel, the public and the environment.

[0004] At present, the conventional design and layout of the emergency ventilation system of the main control room of a nuclear power plant can be found in Figure 1 .like Figure 1 As shown in the figure, the main control room of a nuclear power plant is designed with an emergency ventilation system. The emergency ventilation system in the habitable area of ​​the main control room is generally composed of normal ventilation and air purification units. The core components of the air purification unit are high-efficiency filters that filter radioactive aerosols and iodine adsorbers that adsorb radioactive iodine in the air. Under normal operating conditions, the normal air conditioning unit provides normal external fresh air and air temperature and humidity adjustment functions to the main control room of the nuclear power plant; under severe accident conditions, the air purification unit purifies the external radioactive contaminated air and adjusts the temperature and humidity through the normal air conditioning unit before providing it to the main control room. However, the internal leakage test results of the main control room so far have confirmed that the design and installation of these emergency ventilation systems still inevitably have unfiltered air leakage. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a ventilation system for the habitable area of ​​a nuclear power plant, which is conducive to zero internal leakage of unfiltered air in the habitable area of ​​the nuclear power plant and improves the safety of the nuclear power plant.

[0006] According to the present invention, the ventilation system of the habitable area of ​​a nuclear power plant includes: an air purification unit, which is used to purify the air outside the habitable area, and an air outlet is arranged at one end of the air purification unit, and the air outlet is provided with an air outlet pipe with a certain length; an air conditioning unit, which is used to circulate the air inside the habitable area, and the air conditioning unit includes an air inlet and an air outlet; a circulation duct, which connects the air purification unit and the air conditioning unit, and the circulation duct includes a circulation return air duct and an air supply duct, one end of the circulation return air duct is connected to the air outlet pipe of the air purification unit, and the other end is connected to the air inlet of the air conditioning unit; the air conditioning unit and the circulation duct are arranged inside the habitable area, and the air purification unit is arranged outside the habitable area; the air outlet pipe runs from the air outlet of the air purification unit outside the habitable area to the inside of the habitable area, and is connected to the circulation duct inside the habitable area.

[0007] Preferably, the air purification unit includes a fan for drawing air outside the habitable area into the habitable area, and a purification unit for purifying the air drawn in by the fan.

[0008] Preferably, the purification unit includes a high-efficiency filter for filtering radioactive aerosols in the air and an iodine adsorber for adsorbing radioactive iodine in the air; the purification unit is installed inside the box of the air purification unit through a rack, and is configured in a form of serial connection in the order of the high-efficiency filter, the iodine adsorber, and the high-efficiency filter.

[0009] Preferably, the high efficiency filter and the iodine adsorber in the air purification unit are arranged at a position close to the habitable area, and the fan in the air purification unit is arranged at a position away from the habitable area.

[0010] Preferably, the circulation duct is an air duct laid inside the habitable area; a plurality of return air ducts are arranged in parallel on the circulation return air duct, and a plurality of supply air ducts are arranged in parallel on the supply air duct.

[0011] Preferably, a flow control valve is respectively provided on the plurality of return air ducts and the plurality of supply air ducts.

[0012] Preferably, the air conditioning unit is an internal air circulation unit capable of cooling and / or heating, and does not draw air from outside the habitable area during operation.

[0013] Preferably, an air inlet is arranged at one end of the air conditioning unit, and an air outlet is arranged at the other end of the air conditioning unit, and the air outlet is connected to the air supply duct.

[0014] Preferably, a temperature and humidity control module is provided inside the air-conditioning unit.

[0015] Preferably, the high efficiency filter is a HEPA filter.

[0016] Any of the above technical solutions of the present invention can achieve at least one of the following beneficial effects:

[0017] The ventilation system layout scheme for the habitable area of ​​a nuclear power plant provided by the present invention is conducive to zero internal leakage of unfiltered air inside the habitable area of ​​the nuclear power plant, reduces radiation hazards to workers in the habitable area, and has great radiation protection significance and safety value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the ventilation system layout for habitable areas of a conventional nuclear power plant.

[0019] Figure 2 A schematic diagram of a ventilation system arrangement for a habitable area of ​​a nuclear power plant according to the present invention.

[0020] Explanation of reference numerals: 10 air purification unit; 11 fan; 12 high-efficiency filter; 13 iodine adsorber; 14 air outlet duct; 20 air conditioning unit; 21 air inlet; 22 air outlet; 30 circulation duct; 31 return air duct; 32 circulation return air duct; 33 air supply duct; 34 air supply duct; 35 flow control valve; 40 habitable area. DETAILED DESCRIPTION

[0021] The ventilation system layout scheme for the habitable area of ​​a nuclear power plant provided by the present invention is described below in conjunction with the accompanying drawings.

[0022] Figure 1 The following is a schematic diagram of the ventilation system layout for a traditional habitable area. Figure 1 As shown in the figure, the main control room of a nuclear power plant is designed with an emergency ventilation system. The emergency ventilation system in the habitable area is generally composed of normal ventilation and air purification units, and the air conditioning unit is set outside the habitable area. In the case of a serious accident, the air purification unit purifies the external radioactive contaminated air, and then adjusts the temperature and humidity of the air conditioning unit before providing it to the habitable area. This arrangement still inevitably leads to a certain amount of unfiltered air leakage.

[0023] Figure 2 The figure is a schematic diagram of the ventilation system arrangement scheme for the habitable area of ​​a nuclear power plant according to the present invention. Figure 2As shown, a ventilation system for a habitable area provided by the present invention includes: an air purification unit 10, which is used to purify the air outside the habitable area 40; an air conditioning unit 20, which is used to circulate the air inside the habitable area 40; and a circulation duct 30, which connects the air purification unit 10 and the air conditioning unit 20. Further, the circulation duct 30 also includes a circulation return air duct 32 and an air supply duct 33. Further, the air conditioning unit 20 and the circulation duct 30 are arranged inside the habitable area 40, and the air purification unit 10 is arranged outside the habitable area 40.

[0024] The various components of the ventilation system arrangement of the present invention are further described below.

[0025] The air purification unit 10 has an air outlet at one end, and the air purified by the air purification unit 10 can enter the circulating return air duct 32 inside the habitable area 40 through the air outlet. The other end of the air purification unit 10 is provided with an air inlet, and the fan 11 drives the air to enter the interior of the air purification unit 10 from the air inlet.

[0026] Further, the air purification unit 10 includes a fan 11 for drawing air from outside the habitable area 40 into the habitable area 40, and a purification unit for purifying the air drawn in by the fan 11. Further, the purification unit includes a high-efficiency filter 12 for filtering radioactive aerosols in the air and an iodine adsorber 13 for adsorbing radioactive iodine in the air, which are installed inside the box of the air purification unit 10 through a rack, and are configured in a form of being connected in series in the order of the high-efficiency filter 12, the iodine adsorber 13, and the high-efficiency filter 12. Among them, the high-efficiency filter 12 is preferably a HEPA filter. Further, in order to realize the positive pressure air supply of the air purification unit 10, the purification unit in the air purification unit 10 is arranged at a position close to the habitable area 40, and the fan 11 in the air purification unit 10 is arranged at a position away from the habitable area 40, so that the air at the boundary of the habitable area 40 is positive pressure compared to the external pressure. Preferably, the pressure at the boundary of the habitable area 40 is controlled at about 30Pa. Thus, the fresh air outside the habitable area 40 is first drawn in by the fan 11, passes through the high-efficiency filter 12, the iodine adsorber 13, and the high-efficiency filter 12 in sequence, and is finally sent to the inside of the habitable area 40, thereby effectively preventing the unfiltered air from entering the inside of the habitable area 40. Optionally, when the boundary of the habitable area 40 is well sealed, the pressure at the boundary of the habitable area may reach 50Pa or even above 50Pa. At this time, in order to maintain the pressure at the boundary of the habitable area at 30Pa, one or more pressure relief ports (not shown in the figure) need to be provided at the boundary of the habitable area.

[0027] Furthermore, the air outlet end of the air purification unit 10 is provided with an air outlet pipe 14 having a certain length, and the air outlet pipe 14 runs from the air outlet end of the air purification unit 10 outside the habitable area 40 to the inside of the habitable area 40, and is connected to the circulating return air duct 32 of the circulating duct 30 inside the habitable area 40 to prevent the unfiltered air outside the habitable area 40 from entering the inside of the habitable area 40. Furthermore, in order to ensure air tightness, the air outlet pipe 14 is not provided with perforations.

[0028] Optionally, the air purifier is configured as multiple independent units in multiple rows, of which only one can be operated under normal circumstances, and multiple rows of units can be operated simultaneously under special circumstances to further ensure the positive pressure of the air at the boundary of the habitable area 40. Optionally, the air volume range of the air purifier unit 10 can be calculated according to the number of operators inside the habitable area 40 to ensure that the oxygen concentration and carbon dioxide concentration in the main control room meet the relevant requirements.

[0029] like Figure 2 As shown, the air conditioning unit 20 is arranged inside the habitable area 40, and is an internal air circulation unit that can cool and / or heat, that is, it does not take air from the outside of the habitable area 40 during operation. The air conditioning unit 20 operates independently from the air purification unit 10. Optionally, the air conditioning unit 20 is arranged in other rooms inside the habitable area 40 that are different from the room where the circulation duct 30 is located. An air inlet 21 is arranged at one end of the air conditioning unit 20, and the air inlet 21 is connected to the air outlet duct 14 at the air outlet end of the air purification unit 10 through the circulation return air duct 32. An air outlet 22 is arranged at the other end of the air conditioning unit 20, and the air outlet 22 is connected to the air supply duct 33 of the circulation duct 30. Further, a temperature and humidity control module is arranged inside the air conditioning unit 20 to realize the control of the temperature and humidity inside the habitable area 40 and increase the comfort inside the habitable area 40.

[0030] The air purification unit 10 and the air conditioning unit 20 are connected via a circulation duct 30, and the circulation duct 30 includes a circulation return air duct 32 and an air supply duct 33. Figure 2As shown, the circulation duct 30 is an air duct laid inside the habitable area 40 so that the purified air circulates inside the habitable area 40. Furthermore, a plurality of return air ducts 31 are arranged in parallel on the circulation return air duct 32 arranged inside the habitable area 40, and a plurality of supply air ducts 34 are arranged in parallel on the supply air duct 33 arranged inside the habitable area 40. Through such a design, the air inside the habitable area 40 and the air purified by the air purification unit 10 can be combined at the circulation return air duct 32 in the habitable area 40, and then pumped to the air outlet 22 of the air conditioning unit 20 through the air inlet 21 of the air conditioning unit 20, and finally delivered to the habitable area 40 through the plurality of supply air ducts 34 of the supply air duct 33, thereby allowing the purified air to circulate inside the habitable area 40.

[0031] Furthermore, flow control valves 35 are respectively provided on each of the return air ducts 31 arranged in parallel and each of the supply air ducts 34 arranged in parallel. By controlling the flow control valves 35, the air that needs to enter the air-conditioning unit 20 and the air that needs to be supplied into the habitable area through the supply air ducts 34 can be adjusted as needed to achieve precise control of the gas pressure in the habitable area 40.

[0032] The ventilation system layout scheme for the habitable area of ​​a nuclear power plant provided by the present invention is conducive to zero internal leakage of unfiltered air inside the habitable area of ​​the nuclear power plant, reduces radiation hazards to workers in the habitable area, and has great radiation protection significance and safety value.

[0033] The above is a description of the embodiments of the present invention. The above embodiments are merely illustrative of the present invention, and the present invention may also be implemented in other specific ways or other specific forms without departing from the gist or essential features of the present invention. Therefore, the described embodiments should be considered illustrative rather than restrictive in any respect. The scope of the present invention should be described by the attached claims, and any changes equivalent to the intent and scope of the claims should also be included in the scope of the present invention.

Claims

1. A ventilation system for habitable areas of a nuclear power plant, characterized in that: include: An air purification unit, which is used to purify the air outside the habitable area, wherein an air outlet is provided at one end of the air purification unit, and an air outlet pipe having a certain length is provided at the air outlet; an air conditioning unit, which is used to circulate air inside the habitable area, the air conditioning unit comprising an air inlet and an air outlet; A circulation duct, which connects the air purification unit and the air conditioning unit, the circulation duct includes a circulation return air duct and an air supply duct, one end of the circulation return air duct is connected to the air outlet pipe of the air purification unit, and the other end is connected to the air inlet of the air conditioning unit; The air conditioning unit and the circulation duct are arranged inside the habitable area, and the air purification unit is arranged outside the habitable area; The air outlet pipe extends from the air outlet end of the air purification unit outside the habitable area to the inside of the habitable area, and is connected to the circulation duct inside the habitable area.

2. The ventilation system for habitable areas of a nuclear power plant according to claim 1, characterized in that: The air purification unit includes a fan for drawing air outside the habitable area into the habitable area, and a purification unit for purifying the air drawn in by the fan.

3. The ventilation system for habitable areas of a nuclear power plant according to claim 2, characterized in that: The purification unit includes a high efficiency filter for filtering radioactive aerosols in the air and an iodine adsorber for adsorbing radioactive iodine in the air; The purification unit is installed inside the box of the air purification unit through a rack, and is configured in a form of being connected in series in the order of the high-efficiency filter, the iodine adsorber, and the high-efficiency filter.

4. The ventilation system for habitable areas of a nuclear power plant according to claim 3, characterized in that: The high-efficiency filter and the iodine adsorber in the air purification unit are arranged at a position close to the habitable area, and the fan in the air purification unit is arranged at a position far away from the habitable area.

5. The ventilation system for habitable areas of a nuclear power plant according to claim 1, characterized in that: The circulation pipeline is an air duct laid inside the habitable area; The circulating return air duct is provided with a plurality of return air ducts in parallel, and the supply air duct is provided with a plurality of supply air ducts in parallel.

6. The ventilation system for habitable areas of a nuclear power plant according to claim 5, characterized in that: Flow control valves are respectively provided on the plurality of return air ducts and the plurality of supply air ducts.

7. The ventilation system for habitable areas of a nuclear power plant according to claim 1, characterized in that: The air conditioning unit is an internal air circulation unit capable of cooling and / or heating, and does not draw air from outside the habitable area during operation.

8. The ventilation system for habitable areas of a nuclear power plant according to claim 7, characterized in that: An air inlet is arranged at one end of the air conditioning unit, and an air outlet is arranged at the other end of the air conditioning unit, and the air outlet is connected to the air supply duct.

9. A ventilation system for habitable areas of a nuclear power plant according to any one of claims 1 to 8, characterized in that: A temperature and humidity control module is arranged inside the air conditioning unit.

10. A ventilation system for habitable areas of a nuclear power plant according to any one of claims 1 to 8, characterized in that: The high efficiency filter is a HEPA filter.

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