Nuclear reactor enclosure structure internal negative pressure maintaining device and control method

Abstract

The invention provides a nuclear reactor enclosure structure internal negative pressure maintaining device and a control method, and belongs to the technical field of nuclear reactor gas leakage prevention. The device comprises a variable-frequency exhaust air handling unit communicated with a high-altitude exhaust device. The exhaust outlet is communicated with the variable-frequency exhaust air handling unit through an air pipeline, and an adjusting air valve is arranged on the air pipeline; the exhaust outlet and the differential pressure sensor are arranged in an airtight window, an airtight door, a steam pipeline and an electrical element area which are easy to generate pressure mutation in the enclosure structure; the temperature sensors are arranged in a steam pipeline area and an electrical element area which are prone to sudden temperature change; the negative pressure control module is in communication connection with the variable-frequency exhaust air handling unit, the adjusting air valve, the differential pressure sensor and the temperature sensor. A leakage risk area in the enclosure structure can be effectively covered, it is ensured that the enclosure structure quickly returns to a negative pressure state after a negative pressure accident, the negative pressure control feedback time in the enclosure structure is greatly shortened, and then the possibility that polluted air inside and outside leaks outwards is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear reactor gas leakage prevention, and in particular relates to a negative pressure maintaining device and a control method inside a nuclear reactor enclosure structure. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] For enclosure structures in special application scenarios, such as nuclear reactor halls, it is necessary to prevent internal harmful gases from leaking into the external environment and causing pollution to the surrounding environment. The production and installation costs of enclosure structures formed by high-airtightness metal containment are very high. Maintaining a negative pressure inside the enclosure structure relative to the external environment, thereby making the internal harmful gases lose the power to leak out, is a low-cost method to prevent the leakage of harmful gases inside the enclosure structure. At present, most enclosure structures are made of concrete structures, but the enclosure structure is prone to leakage at the airtight boundary. The airtight boundary includes concrete walls, roofs, bottom surfaces, as well as airtight doors, airtight windows, etc. Among them, airtight doors and airtight windows are weak points for gas leakage because they have the function of opening. However, the following problems mainly exist in the process of preventing the leakage of harmful gases inside the enclosure structure by maintaining a negative pressure inside the enclosure structure:

[0004] (1) The negative pressure maintenance system often cannot completely cover all leakage risk areas and leakage paths at the boundary of the enclosure structure, and there is still a risk of air leaking out from inside the enclosure structure.

[0005] (2) The existing negative pressure maintenance system has a weak ability to cope with various emergencies. There are high-pressure steam pipelines and electrical components inside the nuclear reactor containment structure. When high-pressure steam pipelines or electrical components fail, the air pressure inside the containment structure will often increase rapidly, destroying the internal negative pressure environment.

[0006] (3) When there is a risk of gas leakage in the enclosure structure, the negative pressure maintenance system is often required to be able to promptly sense the changes in negative pressure inside the enclosure structure and provide timely feedback on the negative pressure control inside the enclosure structure. However, the current negative pressure maintenance system cannot effectively and timely sense and control the internal negative pressure, which can easily cause toxic gas leakage and spread, and thus cause major safety accidents. Summary of the invention

[0007] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a device and control method for maintaining negative pressure inside a nuclear reactor containment structure. By setting up multiple variable frequency exhaust air handling units, the reliability of the device is enhanced; by setting up multiple exhaust outlets, when any branch exhaust outlet or air valve fails, other exhaust outlets can still work to maintain negative pressure. The air duct pipeline connects the variable frequency exhaust air handling unit, the exhaust outlet, the regulating air valve, and the high-altitude discharge device together. The negative pressure control module receives and processes the signals of the pressure difference sensor, the pressure sensor, and the temperature sensor to adjust the opening, frequency, and opening of the variable frequency exhaust air handling unit. It effectively ensures that the negative pressure inside the containment structure is always at a stable value to avoid the spread of toxic gases.

[0008] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0009] A first aspect of the present invention provides a device for maintaining negative pressure inside a nuclear reactor enclosure structure;

[0010] A device for maintaining negative pressure inside a nuclear reactor enclosure structure, comprising:

[0011] A variable frequency exhaust air handling unit, wherein the variable frequency exhaust air handling unit is connected to a high altitude exhaust device;

[0012] An exhaust port, the exhaust port is connected to the variable frequency exhaust air handling unit through an air duct pipeline, and an adjusting air valve is arranged on the air duct pipeline;

[0013] A pressure differential sensor, wherein the pressure differential sensor is respectively arranged in the airtight window, airtight door, steam pipeline and electrical component area inside the enclosure structure;

[0014] A temperature sensor is disposed in a steam pipeline and an electrical component area inside the enclosure structure;

[0015] A negative pressure control module is respectively connected to the variable frequency exhaust air handling unit, the regulating air valve, the pressure difference sensor and the temperature sensor for communication, receives and processes the signals from the pressure difference sensor and the temperature sensor, and controls the opening of the regulating air valve and the exhaust frequency of the variable frequency exhaust air handling unit, so that the negative pressure in each area inside the enclosure structure is always in a set stable state.

[0016] As a further technical solution, at least two variable frequency exhaust air handling units are provided, and the variable frequency exhaust air handling units are connected in parallel with each other.

[0017] As a further technical solution, the variable frequency exhaust air handling unit includes a variable frequency fan, a filter and an adsorber, which are used to exhaust the air inside the enclosure structure to form a negative pressure, and at the same time filter the exhausted gas and adsorb harmful substances.

[0018] As a further technical solution, the exhaust outlet includes a first exhaust outlet, a second exhaust outlet, a third exhaust outlet and a fourth exhaust outlet; the first exhaust outlet, the second exhaust outlet, the third exhaust outlet and the fourth exhaust outlet respectively correspond to the airtight windows, airtight doors, steam pipes and electrical component areas inside the enclosure structure.

[0019] As a further technical solution, the regulating air valve includes a first regulating air valve, a second regulating air valve, a third regulating air valve and a fourth regulating air valve; the first regulating air valve, the second regulating air valve, the third regulating air valve and the fourth regulating air valve are respectively arranged on the air duct pipeline connected to the first exhaust outlet, the second exhaust outlet, the third exhaust outlet and the fourth exhaust outlet.

[0020] As a further technical solution, the differential pressure sensor includes a first differential pressure sensor, a second differential pressure sensor, a third differential pressure sensor and a fourth differential pressure sensor which are respectively arranged in the airtight windows, airtight doors, steam pipelines and electrical component areas inside the enclosure structure.

[0021] As a further technical solution, the first differential pressure sensor and the second differential pressure sensor are used to monitor the pressure difference between the airtight window area and the airtight door area and the outside atmosphere respectively; the third differential pressure sensor is used to monitor the pressure difference between the airtight window area and the steam pipe area; the fourth differential pressure sensor is used to monitor the pressure difference between the electrical component area and the outside atmosphere.

[0022] As a further technical solution, the temperature sensor includes a first temperature sensor and a second temperature sensor respectively arranged in the steam pipeline area and the electrical component area.

[0023] A second aspect of the present invention provides a control method for maintaining negative pressure inside a nuclear reactor containment structure.

[0024] A control method for maintaining negative pressure inside a nuclear reactor containment structure, comprising:

[0025] The pressure difference data between the interior of the enclosure structure and the pressure difference data between the interior of the enclosure structure and the outside atmosphere are obtained based on the pressure difference sensor;

[0026] Based on the temperature data of steam pipes and electrical components inside the enclosure structure;

[0027] The acquired pressure difference data and temperature data are transmitted to the negative pressure control module, and the negative pressure control module controls the opening of the air valve and the exhaust frequency of the variable frequency exhaust air handling unit according to the input data, so that the negative pressure in each area inside the enclosure structure is always in a set stable state.

[0028] As a further technical solution, the pressure difference data inside the enclosure structure includes the pressure difference between the airtight window and the steam pipe area; the pressure difference data between the inside of the enclosure structure and the outside atmosphere includes the pressure difference between the airtight window, the airtight door and the outside atmosphere, and the pressure difference between the electrical component area and the outside atmosphere.

[0029] One or more of the above technical solutions have the following beneficial effects:

[0030] (1) The device for maintaining negative pressure inside a nuclear reactor containment structure provided in the present invention can effectively cover all leakage risk areas inside the nuclear reactor containment structure. By pre-identifying leakage risk areas, such as airtight doors, airtight windows, construction joints, penetrations, etc., the exhaust vents are directly arranged near the leakage risk areas. Meanwhile, the exhaust ducts and exhaust air handling units are preferably arranged near the exhaust vents. This maximizes the negative pressure control capability and minimizes the risk of leakage of contaminated air inside the containment structure.

[0031] (2) For various disturbances that affect negative pressure inside and outside the enclosure structure, such as sudden increase in pressure inside the enclosure structure, sudden increase in internal temperature, and negative pressure accidents on the external walls of the enclosure structure caused by strong winds. The negative pressure control module of the negative pressure maintenance device can dynamically adjust the number of variable frequency exhaust air filter units, exhaust fan frequency, and the opening of each branch air valve according to the readings of the pressure difference and temperature sensor. On the one hand, it can achieve the ability to quickly return to the negative pressure state after various sudden damage negative pressure accidents. On the other hand, it can also achieve the lowest energy consumption pressure difference setting value in each area, avoiding excessive local or overall negative pressure in the enclosure structure and causing energy waste.

[0032] (3) By placing the pressure difference and temperature sensors in the area most likely to cause negative pressure changes, the negative pressure changes inside the enclosure structure can be sensed more quickly; by setting the exhaust outlet in the area most likely to cause negative pressure changes, arranging the exhaust air handling unit close to the exhaust outlet, and arranging the air duct to the shortest distance, the negative pressure changes inside the enclosure structure can be controlled more quickly; by setting up multiple exhaust air handling units, variable frequency exhaust fans, and coordinated adjustment of the opening of multiple air valves, the negative pressure changes inside the enclosure structure can be controlled to the pressure difference set value more quickly, avoiding the positive pressure from spreading to the boundary of the enclosure structure to the greatest extent, greatly reducing the negative pressure control feedback time inside the enclosure structure, and thus avoiding the possibility of internal and external polluted air leaking out.

[0033] (4) Redundant configuration of the variable frequency exhaust air handling units in the negative pressure maintenance device. When one variable frequency exhaust air handling unit fails, other variable frequency exhaust air handling units can still work normally and still achieve the negative pressure maintenance capability inside the enclosure structure. The exhaust vents and corresponding regulating air valves are also arranged in multiple zones. When one regulating air valve fails or the exhaust vent is blocked, other exhaust vents and air valves can still work normally. In this way, due to the connectivity of each zone, the negative pressure maintenance system can still achieve the negative pressure maintenance capability inside the enclosure structure. In addition, by setting filters and adsorbers in the variable frequency exhaust air handling units, harmful substances in the air inside the enclosure structure can be filtered and adsorbed to avoid pollution of the outside air.

[0034] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 This is a schematic diagram of the internal negative pressure maintaining device of the enclosure structure of the first embodiment.

[0037] Figure 2 This is a schematic diagram of a negative pressure control module of the device for maintaining negative pressure inside the enclosure structure of the first embodiment.

[0038] Figure 3 This is a flow chart of a control method for maintaining negative pressure inside a protective structure according to the second embodiment.

[0039] Figure 4 This is a negative pressure control strategy for the second embodiment when a sudden pressure rise occurs in a certain area inside the enclosure structure.

[0040] Figure 5 This is the negative pressure control strategy for the second embodiment when the temperature of a certain area inside the enclosure structure suddenly rises.

[0041] Figure 6 This is a negative pressure control strategy for the second embodiment when there is a sudden pressure drop in individual areas outside the enclosure structure.

[0042] In the figure, 1 is an airtight window; 2 is an airtight door; 3 is a steam pipeline; 4 is an electrical component; 5 is a first variable frequency exhaust air handling unit; 6 is a second variable frequency exhaust air handling unit; 7 is a first regulating air valve; 8 is a second regulating air valve; 9 is a third regulating air valve; 10 is a fourth regulating air valve; 11 is a first exhaust port; 12 is a second exhaust port; 13 is a third exhaust port; 14 is a fourth exhaust port; 15 is a high-altitude exhaust device; 16 is a first differential pressure sensor; 17 is a second differential pressure sensor; 18 is a third differential pressure sensor; 19 is a fourth differential pressure sensor; 20 is a first temperature sensor; 21 is a second temperature sensor; DETAILED DESCRIPTION

[0043] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0044] It should be noted that the terms used herein are for describing specific embodiments only and are not intended to be limiting of exemplary embodiments according to the present invention.

[0045] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0046] Embodiment 1

[0047] This embodiment discloses a negative pressure maintaining device for a nuclear reactor enclosure structure. In this embodiment, the enclosure structure is a reactor hall of a concrete structure, such as Figure 1 As shown. Since the reactor hall is the last barrier to prevent the leakage of radioactive gas, the inside of the reactor hall containment structure needs to maintain a negative pressure relative to the outside, so as to ensure that there is no power source for the internal gas to leak out, and thus ensure that there will be no leakage of radioactive gas inside the containment structure.

[0048] like Figure 1 As shown, a device for maintaining negative pressure inside a nuclear reactor containment structure comprises:

[0049] A variable frequency exhaust air handling unit, wherein the variable frequency exhaust air handling unit is connected to the high altitude exhaust device 15; and at least two variable frequency exhaust air handling units are provided, namely, a first variable frequency exhaust air handling unit 5 and a second variable frequency exhaust air handling unit 6, and the two variable frequency exhaust air handling units are connected in parallel with each other. Through redundant configuration, when one variable frequency exhaust air handling unit fails, the other variable frequency exhaust air handling units can still work normally and can still achieve the ability to maintain negative pressure inside the enclosure structure. In this embodiment, the variable frequency exhaust air handling unit includes a variable frequency fan, a filter and an adsorber, which are used to exhaust the air inside the enclosure structure to form a negative pressure, and can also filter the exhausted gas and adsorb harmful substances to avoid pollution to the outside air.

[0050] The variable frequency exhaust air handling unit is connected to the exhaust port through the air duct pipeline, and the air duct pipeline is provided with an adjustable air valve to adjust the flow rate inside the air duct pipeline. And the variable frequency exhaust air handling unit is preferably set and arranged at the shortest position from all exhaust ports, so as to ensure the minimum flow resistance of the exhaust air flow, thereby achieving the best exhaust effect and the minimum energy consumption. The exhaust outlet includes a first exhaust outlet 11, a second exhaust outlet 12, a third exhaust outlet 13 and a fourth exhaust outlet 14; the regulating air valve includes a first regulating air valve 7, a second regulating air valve 8, a third regulating air valve 9 and a fourth regulating air valve 10; the first regulating air valve 7, the second regulating air valve 8, the third regulating air valve 9 and the fourth regulating air valve 10 are respectively arranged on the air duct pipeline connected to the first exhaust outlet 11, the second exhaust outlet 12, the third exhaust outlet 13 and the fourth exhaust outlet 14. In this embodiment, the direction of the air duct pipeline is arranged as straight pipes as much as possible, the fewer bends are set, the better, and the larger the bending angle of the bend is, the better, so as to ensure that the flow resistance of the airflow in the pipeline is minimized, thereby achieving the optimal exhaust effect and the minimum energy consumption.

[0051] The first exhaust vent 11, the second exhaust vent 12, the third exhaust vent 13 and the fourth exhaust vent 14 correspond to the airtight window 1, the airtight door 2, the steam pipeline 3 and the electrical component 4 areas inside the enclosure structure where sudden pressure changes are prone to occur. The airtight boundary of the reactor hall enclosure structure is the place where gas leakage is most likely to occur. The airtight boundary includes the concrete wall, roof, bottom surface of the enclosure structure, and also includes the airtight door 2, the airtight window 1, etc. Among them, the airtight door 2 and the airtight window 1 are weak points for gas leakage because they have the opening function. Once the pressure inside the airtight door and window is higher than the outside, the internal gas will leak out. In addition, since there are steam pipelines 3 and electrical components 4 inside the reactor hall enclosure structure, when the high-pressure steam pipelines 3 and electrical components 4 fail, it is easy to cause the internal air pressure of the enclosure structure to rise sharply, destroy the internal negative pressure environment, and then cause a gas leakage accident. Based on the above considerations, in this embodiment, the exhaust vents are respectively arranged in the airtight windows 1, airtight doors 2, steam pipes 3 and electrical components 4 areas where sudden changes in air pressure or temperature are prone to occur, so that the negative pressure environment inside the enclosure structure can be quickly restored through the exhaust vents in the event of a fault.

[0052] Furthermore, a pressure difference sensor, a temperature sensor and a negative pressure control module are also provided in the internal negative pressure maintaining device. Figure 2 , wherein the negative pressure control module is respectively connected to the differential pressure sensor and the temperature sensor for communication, and obtains and processes the differential pressure and temperature data collected by the differential pressure sensor and the temperature sensor. The two pressure interfaces of the differential pressure sensor are respectively extended to the test area through the connecting pipe, and the differential pressure value is detected by the change of the capacitance value caused by the displacement of the internal diaphragm. As an existing technology, the differential pressure sensor is not described in detail here.

[0053] In this embodiment, the differential pressure sensors are also arranged in the airtight window 1, airtight door 2, steam pipeline 3 and electrical component 4 areas inside the enclosure structure where sudden changes in air pressure are prone to occur, wherein the differential pressure sensors include a first differential pressure sensor 16, a second differential pressure sensor 17, a third differential pressure sensor 18 and a fourth differential pressure sensor 19; the first differential pressure sensor 16 and the second differential pressure sensor 17 are respectively used to monitor the pressure difference between the airtight window 1 area, the airtight door 2 area and the outside atmosphere; the third differential pressure sensor 18 is used to monitor the pressure difference between the airtight window 1 area and the steam pipeline 3 area; the fourth differential pressure sensor 19 is used to monitor the pressure difference between the electrical component 3 area and the outside atmosphere.

[0054] The temperature sensor comprises a first temperature sensor 20 and a second temperature sensor 21 respectively arranged in the steam pipeline 3 and the electrical component 4 regions where sudden temperature changes are prone to occur, and used to detect the temperatures of the steam pipeline 3 and the electrical component 4 regions respectively.

[0055] Combination Figure 2The negative pressure control module is also connected to the variable frequency exhaust air handling unit and the regulating air valve, and controls the opening of the regulating air valve and the exhaust frequency of the variable frequency exhaust air handling unit according to the acquired pressure difference data and temperature data, ensuring that the interior of the enclosure structure is always in a stable negative pressure state under different conditions.

[0056] Embodiment 2

[0057] This embodiment discloses a control method for maintaining negative pressure inside a nuclear reactor containment structure;

[0058] A control method for maintaining negative pressure inside a nuclear reactor containment structure, comprising:

[0059] The pressure difference data between the interior of the enclosure structure and the pressure difference data between the interior of the enclosure structure and the outside atmosphere are obtained based on the pressure difference sensor;

[0060] Based on the temperature data of steam pipes and electrical components inside the enclosure structure;

[0061] The acquired pressure difference data and temperature data are transmitted to the negative pressure control module, and the negative pressure control module controls the opening of the air valve and the exhaust frequency of the variable frequency exhaust air handling unit according to the input data to ensure that the interior of the enclosure structure is always in a stable negative pressure state under different conditions.

[0062] Combination Figure 3 , set dp i is the reading of the ith differential pressure sensor, T j is the reading of the jth temperature sensor, P limit is the differential pressure setting value, T limit is the temperature difference setting value, and e is the set value deviation allowable value. First determine the reading dp of each differential pressure sensor i Is it greater than the set pressure difference setting value P? limit Or each temperature sensor T j Is the reading greater than the temperature setting value T limit, when the above conditions are not met, it means that the enclosure structure is in a normal negative pressure state, and the risk of toxic gas leakage is low. At this time, the opening of the regulating air valve and the exhaust frequency of the variable frequency exhaust air handling unit can be maintained; when the sensor reading is greater than the set value, it means that there is a risk of leakage at this time, and the opening of the regulating air valve and the exhaust frequency of the variable frequency exhaust air handling unit need to be adjusted so that the sensor reading is less than the set value. Further, on the basis of the above, the opening of the regulating air valve is further adjusted to determine whether the difference between the pressure difference sensor and the pressure difference setting value is less than or equal to the set value deviation allowable value. When the above conditions are met, the opening of the regulating air valve and the exhaust frequency of the variable frequency exhaust air handling unit are maintained. When not met, the opening of the regulating air valve is continued to be adjusted until the above conditions are met. By setting the set value deviation allowable value, each area can achieve the lowest energy consumption pressure difference setting value, avoiding excessive local or overall negative pressure in the enclosure structure and causing energy waste. The following will describe the negative pressure maintenance plan in detail in combination with specific scenarios.

[0063] (1) Negative pressure maintenance plan during normal operation of the enclosure structure

[0064] When the enclosure structure operates normally, the negative pressure control module only turns on one variable frequency exhaust air handling unit, such as the first variable frequency exhaust air handling unit 5, and adjusts the exhaust frequency of the first variable frequency exhaust air handling unit 5 and the opening of the first regulating air valve 7 and the second regulating air valve 8 according to the readings of the first differential pressure sensor 16 and the second differential pressure sensor 17, so that the readings of the first differential pressure sensor 16 and the second differential pressure sensor 17 are the pressure difference setting values, preferably -30Pa.

[0065] The third differential pressure sensor 18 is used to monitor the pressure difference between the airtight window 1 and the steam pipeline 3 area. The preferred pressure difference setting value is -10Pa, ensuring that the negative pressure control in this negative pressure danger zone is more conservative. The fourth differential pressure sensor 19 is used to monitor the pressure difference between the electrical component 4 area and the outside atmosphere. The preferred pressure difference setting value is -40Pa, ensuring that the negative pressure control in this negative pressure danger zone is more conservative. According to the readings of the third differential pressure sensor 18 and the fourth differential pressure sensor 19, the exhaust frequency of the first variable frequency exhaust air handling unit 5 and the opening of the third regulating air valve 9 and the fourth regulating air valve 10 are adjusted to maintain the readings of the third differential pressure sensor 18 and the fourth differential pressure sensor 19 at the set value.

[0066] (2) Negative pressure maintenance plan when high pressure suddenly occurs inside the enclosure structure

[0067] When high pressure suddenly occurs inside the enclosure structure, Figure 4When the steam pipe 3 ruptures, a large amount of steam is ejected instantly, causing the pressure in the room to rise rapidly. At this time, the third pressure difference sensor 18 instantly becomes positive pressure, and the positive pressure increases rapidly. The reading of the first temperature sensor 20 also increases rapidly. The negative pressure control module senses the pressure difference signal of the third pressure difference sensor 18 and the temperature signal of the first temperature sensor 20, and determines that it is a rupture accident, then quickly starts the first variable frequency exhaust air handling unit 5 and the second variable frequency exhaust air handling unit 6, and adjusts the exhaust frequency of the unit to the maximum, and then adjusts the opening of the third regulating air valve 9 of the third exhaust port 13 leading to the rupture position to the maximum, and the other regulating air valves are quickly closed according to the pressure difference setting value, so that the exhaust capacity of the third exhaust port 13 at the rupture position reaches the strongest, which can maximize the relief of the increase in positive pressure and minimize the possibility of transmitting positive pressure to the boundary of the enclosure structure, thereby ensuring the negative pressure maintenance capacity of the boundary of the enclosure structure and reducing the possibility of gas leakage from the boundary of the enclosure structure to the maximum.

[0068] After the pressure difference of the third pressure difference sensor 18 at the breach position returns to negative pressure, the negative pressure control module shuts down a variable frequency exhaust air handling unit, and then adjusts the exhaust frequency of the variable frequency exhaust air handling unit and the opening of four regulating air valves according to the readings and set values ​​of the four pressure difference sensors, so that the negative pressure is controlled within the set value range, thereby realizing the negative pressure maintenance function.

[0069] (3) Negative pressure maintenance plan when high temperature suddenly occurs inside the enclosure structure

[0070] When high temperature suddenly occurs inside the enclosure structure, such as Figure 5 , the electrical component 4 instantly generates a large amount of heat, the reading of the second temperature sensor 21 suddenly increases, the heat causes the surrounding air to be quickly heated, and the pressure in the room increases rapidly. At this time, the fourth pressure difference sensor 19 instantly becomes positive pressure, and the positive pressure increases rapidly. The negative pressure control module senses the pressure difference signal of the fourth pressure difference sensor 19 and the temperature signal of the second temperature sensor 21, and judges it as a sudden temperature rise accident according to the curve shape and the occurrence location, then quickly turns on the first variable frequency exhaust air handling unit 5 and the second variable frequency exhaust air handling unit 6, and adjusts the exhaust frequency to the maximum, and then adjusts the opening of the fourth regulating air valve 10 leading to the fourth exhaust port 14 at the breach position to the maximum, and the other regulating air valves are quickly closed according to the pressure difference setting value, so that the exhaust capacity of the fourth exhaust port 14 at the breach position reaches the strongest, which can maximize the relief of the increase in positive pressure and minimize the possibility of positive pressure being transmitted to the boundary of the enclosure structure, thereby ensuring the negative pressure maintenance capacity of the boundary of the enclosure structure and minimizing the possibility of gas leakage from the boundary of the enclosure structure.

[0071] After the pressure difference of the fourth differential pressure sensor 19 at the breach position returns to negative pressure, the negative pressure control module shuts down a variable frequency exhaust air handling unit, and then adjusts the exhaust frequency of the variable frequency exhaust air handling unit and the opening of the four regulating air valves according to the readings and set values ​​of the four differential pressure sensors, so that the negative pressure is controlled within the set value range, thereby realizing the negative pressure maintenance function.

[0072] (4) Negative pressure maintenance plan for sudden negative pressure outside the boundary of the enclosure structure

[0073] When strong wind suddenly occurs outside the enclosure structure, positive pressure will be generated on the windward side of the enclosure structure, while negative pressure will be generated in the dynamic shadow area outside the enclosure structure. Figure 6 As shown. At this time, the negative pressure reading of the first differential pressure sensor 16 will decrease rapidly or even become positive pressure, while the negative pressure reading of the second differential pressure sensor 17 will increase rapidly. The negative pressure control module will judge it as a strong wind accident based on the readings of the first differential pressure sensor 16 and the second differential pressure sensor 17, and start to adjust the exhaust fan frequency of the first variable frequency exhaust air handling unit 5, increase the opening of the first regulating air valve 7, and then increase the exhaust volume of the first exhaust port 11, increase the negative pressure around the airtight window 1, and reduce the risk of air leakage from the airtight window 1. At the same time, reduce the opening of the second regulating air valve 8, and then reduce the negative pressure near the airtight door 2, thereby reducing the energy consumption of the negative pressure maintenance system under the premise of ensuring the negative pressure capacity. Other dynamic regulating air valves adjust the air valve opening according to their respective pressure difference setting values ​​to achieve negative pressure maintenance capability.

[0074] After the strong wind, the negative pressure control module adjusts the exhaust frequency of the variable frequency exhaust air handling unit and the opening of the four regulating air valves according to the readings and set values ​​of the four pressure difference sensors, so that the negative pressure is controlled within the set value range, thereby realizing the negative pressure maintenance function.

[0075] (5) Negative pressure maintenance plan when variable frequency exhaust air handling unit fails

[0076] When one of the variable frequency exhaust air handling units fails, such as the first variable frequency exhaust air handling unit 5, the negative pressure control module senses the failed unit and immediately starts the other redundant second variable frequency exhaust air handling unit 6, and adjusts the exhaust frequency and the opening of the four regulating air valves to make each pressure difference sensor reach the set value, thereby achieving the negative pressure inside the enclosure structure when one of the variable frequency exhaust air handling units fails.

[0077] (6) Negative pressure maintenance plan when the air valve or exhaust port fails

[0078] When an adjustable air valve fails, such as the first adjustable air valve 7 loses its regulating function, the negative pressure control module senses the failed air valve, and immediately adjusts the exhaust frequency of the first variable frequency exhaust air handling unit 5 and the opening of other adjustable air valves, so that the pressure difference sensor reading is within the set value range. If the pressure difference sensor reading cannot be maintained at the set value, the second variable frequency exhaust air handling unit 6 is turned on, and the negative pressure values ​​of all pressure difference sensors are greater than or equal to the set value by adjusting the exhaust frequency and the opening of other adjustable air valves of the two variable frequency exhaust air handling units. Thus, when any air valve fails, the negative pressure inside the enclosure structure can still be maintained.

[0079] When an exhaust port fails, such as the first exhaust port 11 is blocked or blocked, the negative pressure control module senses that the first differential pressure sensor 16 cannot reach the differential pressure setting value, and the negative pressure control module uses the connectivity of the space to achieve negative pressure in the first exhaust port 11 area through other exhaust ports. At this time, the control target of the negative pressure control module is that the negative pressure value of all differential pressure sensors is greater than or equal to the setting value, rather than adjusting to the setting value. The adjustment measures are to adjust the opening and exhaust frequency of the two variable frequency exhaust air handling units and the opening of other regulating air valves. In this way, when any of the exhaust ports fails, the negative pressure inside the enclosure structure can still be maintained.

[0080] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A device for maintaining negative pressure inside a nuclear reactor containment structure, characterized in that: include: A variable frequency exhaust air handling unit, wherein the variable frequency exhaust air handling unit is connected to a high altitude exhaust device; An exhaust port, the exhaust port is connected to the variable frequency exhaust air handling unit through an air duct pipeline, and an adjusting air valve is arranged on the air duct pipeline; The differential pressure sensors are respectively arranged in the airtight windows, airtight doors, steam pipelines and electrical component areas inside the enclosure structure; A temperature sensor is disposed in a steam pipeline and an electrical component area inside the enclosure structure; A negative pressure control module is respectively connected to the variable frequency exhaust air handling unit, the regulating air valve, the pressure difference sensor and the temperature sensor for communication, receives and processes the signals from the pressure difference sensor and the temperature sensor, and controls the opening of the regulating air valve and the exhaust frequency of the variable frequency exhaust air handling unit, so that the negative pressure inside the enclosure structure is always in a stable temperature state.

2. A device for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 1, characterized in that: At least two variable frequency exhaust air handling units are provided, and the variable frequency exhaust air handling units are connected in parallel with each other.

3. A device for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 1, characterized in that: The variable frequency exhaust air handling unit comprises a variable frequency fan, a filter and an adsorber, and is used to exhaust the air inside the enclosure structure to form a negative pressure, and at the same time filter the exhausted gas and adsorb harmful substances.

4. A device for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 1, characterized in that: The exhaust vents include a first exhaust vent, a second exhaust vent, a third exhaust vent and a fourth exhaust vent; the first exhaust vent, the second exhaust vent, the third exhaust vent and the fourth exhaust vent correspond to the airtight windows, airtight doors, steam pipelines and electrical component areas inside the enclosure structure, respectively.

5. A device for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 1 or 4, characterized in that: The regulating air valve includes a first regulating air valve, a second regulating air valve, a third regulating air valve and a fourth regulating air valve; the first regulating air valve, the second regulating air valve, the third regulating air valve and the fourth regulating air valve are respectively arranged on the air duct pipeline connected to the first exhaust port, the second exhaust port, the third exhaust port and the fourth exhaust port.

6. A device for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 1, characterized in that: The differential pressure sensor comprises a first differential pressure sensor, a second differential pressure sensor, a third differential pressure sensor and a fourth differential pressure sensor which are respectively arranged at the airtight window, the airtight door, the steam pipeline and the electrical component area inside the enclosure structure.

7. A device for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 6, characterized in that: The first differential pressure sensor and the second differential pressure sensor are used to monitor the pressure difference between the airtight window area and the airtight door area and the outside atmosphere respectively; the third differential pressure sensor is used to monitor the pressure difference between the airtight window area and the steam pipe area; the fourth differential pressure sensor is used to monitor the pressure difference between the electrical component area and the outside atmosphere.

8. The device for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 1, characterized in that: The temperature sensor comprises a first temperature sensor and a second temperature sensor respectively arranged in a steam pipeline area and an electrical component area.

9. A control method for maintaining negative pressure inside a nuclear reactor containment structure, characterized in that: include: The pressure difference data between the interior of the enclosure structure and the pressure difference data between the interior of the enclosure structure and the outside atmosphere are obtained based on the pressure difference sensor; Based on the temperature data of steam pipes and electrical components inside the enclosure structure; The acquired pressure difference data and temperature data are transmitted to the negative pressure control module, and the negative pressure control module controls the opening of the air valve and the exhaust frequency of the variable frequency exhaust air handling unit according to the input data, so that the negative pressure inside the enclosure structure is always in a temperature stable state.

10. A control method for maintaining negative pressure inside a nuclear reactor enclosure structure according to claim 9, characterized in that: The pressure difference data between the interior of the enclosure structure includes the pressure difference between the airtight window and the steam pipeline area; the pressure difference data between the interior of the enclosure structure and the outside atmosphere includes the pressure difference between the airtight window, the airtight door and the outside atmosphere, and the pressure difference between the electrical component area and the outside atmosphere.

Images