A balancing system capable of real-time control of fan resistance in iodine filtration pipelines

Abstract

The present invention relates to a balancing system capable of regulating the resistance of a fan of an iodine filter pipeline in real time, and belongs to the field of nuclear energy safety. An electric regulating valve is arranged between an electric heater and a pre-filter, a first differential pressure measuring device is arranged between the electric regulating valve and a post-HEPA filter to monitor the total resistance of the entire iodine filter pipeline, a sub-differential pressure measuring device is arranged on both sides of each filter and an iodine adsorber, and a controller adjusts the electric regulating valve according to the measurement results of the first differential pressure measuring device and the measurement results of each sub-differential pressure measuring device, thereby achieving the effect of regulating the resistance of the iodine filter pipeline in real time. A balancing system capable of regulating the resistance of a fan of an iodine filter pipeline in real time disclosed by the present invention is adopted, so that the operation of the fan on the iodine filter pipeline is kept in a stable and efficient state. Not only the service life of the fan is extended, but also the reliability of the system design is greatly improved, and the safe and efficient operation of the nuclear power plant is ensured.

Description

Technical Field

[0001] The invention belongs to the field of nuclear energy safety, and in particular relates to a balancing system capable of regulating the resistance of a fan of an iodine filtering pipeline in real time. Background Art

[0002] Iodine filter pipelines in nuclear power plants are mainly used in ventilation systems that need to exhaust air to chimneys or in emergency filter ventilation systems in the main control room. The design resistance of the fan in the iodine filter pipeline is often selected based on the total resistance of the iodine adsorber and the HEPA filter or pre-filter in the filter system, see Figure 1 , which will result in the fan design pressure head being too large.

[0003] In the existing design, static balancing valves are often set. In the initial operation stage of the fan, since the pipeline resistance deviates greatly from the rated resistance, the method of reducing the static balancing valve opening and increasing the pipeline resistance is adopted for debugging. As the emergency filter pipeline is put into operation, the filter resistance will increase with the passage of operation time. However, since the static balancing valve used has a fixed resistance during the debugging period, unless the personnel manually increase the balancing valve opening to change the valve resistance, the pipeline resistance will not be adjustable. In this way, as the system runs, the fan air volume will gradually deviate from the designed rated air volume and deviate from the fan's efficient operation area, that is, the actual operating air volume of the fan is small and cannot meet the design requirements, affecting the reliability of the system design. For example, as the filter resistance increases, the pipeline resistance of the emergency filter system in the main control room increases, resulting in insufficient fan output, which is likely to cause the main control room micro-positive pressure to be unable to be guaranteed, and the fresh air for personnel to breathe cannot be guaranteed, which ultimately affects the habitability function of the main control room. Summary of the invention

[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide a balancing system capable of regulating the resistance of the iodine filtration pipeline fan in real time. This device is economical and easy to use, and can effectively solve the problem that the resistance of the iodine filtration pipeline fan changes with the operation of the system.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a balancing system capable of regulating the resistance of a fan of an iodine filtration pipeline in real time, wherein the system sequentially arranges an electric heater, a pre-filter, a pre-HEPA filter, an iodine adsorber, a post-HEPA filter and a fan between a room and an exhaust chimney, an electric regulating valve is arranged between the electric heater and the pre-filter, a first differential pressure measuring device is arranged between the electric regulating valve and the post-HEPA filter to monitor the total resistance of the entire iodine filtration pipeline, a sub-differential pressure measuring device is arranged on both sides of each filter and the iodine adsorber, the first differential pressure measuring device, each sub-differential pressure measuring device and the electric regulating valve are connected to a controller, and the controller adjusts the electric regulating valve according to the measurement results of the first differential pressure measuring device and the measurement results of each sub-differential pressure measuring device.

[0006] Furthermore, each filter includes the pre-filter, the HEPA filter and the post-HEPA filter.

[0007] Furthermore, the opening of the electric regulating valve is adjusted according to the air volume-resistance curve of the electric regulating valve.

[0008] Furthermore, the air volume-resistance curve of the electric regulating valve is obtained by querying the data sheet of the electric regulating valve.

[0009] Furthermore, one side of the first differential pressure measuring device is connected to the upstream of the electric regulating valve, and the other side of the first differential pressure measuring device is connected to the downstream of the post-HEPA filter.

[0010] Furthermore, the fan is an exhaust fan or a supply fan.

[0011] Furthermore, the pressure difference measuring device is a pressure difference gauge or a pressure difference sensor.

[0012] Furthermore, the pressure difference measuring device displays the measurement results in real time.

[0013] The effect of the present invention is that: the use of a balancing system capable of real-time regulation of the resistance of the iodine filter pipeline fan disclosed in the present invention can effectively solve the problem that the iodine filter pipeline fan output is insufficient as the system runs for a long time, thereby causing the system function to be unable to be implemented, and greatly improves the reliability of the system design. The iodine filter pipeline is generally used in the exhaust system of the control area with iodine pollution or in the emergency fresh air filtration system of the habitable area of ​​the main control room when an outdoor pollution accident occurs, and is also applicable to the exhaust system of the iodine filter or HEPA filter pipeline in the control area of ​​other nuclear facilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the arrangement of the iodine filtration pipeline of a general nuclear power plant in the prior art;

[0015] Figure 2 This is a structural schematic diagram of a balancing system capable of regulating the fan resistance of an iodine filtration pipeline in real time, shown in Embodiment 1 of the present invention;

[0016] Among them: 1-room, 2-electric heater, 3-pre-filter, 4-pre-HEPA filter, 5-iodine adsorber, 6-post-HEPA filter, 7-exhaust fan or supply fan, 8-exhaust chimney, 9-static balancing valve, 10-controller, 11-electric regulating valve, 12-differential pressure sensor. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0018] Embodiment 1

[0019] like Figure 1 As shown, in the prior art, a general iodine filter pipeline includes a room 1, an electric heater 2, a pre-filter 3, a pre-HEPA filter 4, an iodine adsorber 5, a post-HEPA filter 6, an exhaust fan or a blower 7, an exhaust chimney 8, and a static balancing valve 9. The resistance P of the filter equipment of the iodine filter pipeline is P1+P2+P3+P4, and the design resistance of the fan is selected according to the final resistance of the equipment 3-6, so the rated pressure head of the fan far exceeds the total resistance of the initial operation of the iodine filter pipeline. Usually, the commissioning personnel adjust the resistance of the iodine filter pipeline by manually adjusting the opening of the static balancing valve 9. However, as the iodine filter pipeline is put into operation, the increase in the filter resistance causes the fan operation to deviate from the high-efficiency operation area, which ultimately causes the fan design air volume to fail to reach the rated air volume, does not meet the design requirements, and greatly reduces the reliability of the system design.

[0020] like Figure 2 As shown, this embodiment provides a balancing system capable of regulating the resistance of the fan of the iodine filtration pipeline in real time, wherein an electric heater 2, a pre-filter 3, a pre-HEPA filter 4, an iodine adsorber 5, a post-HEPA filter 6 and a fan 7 are sequentially arranged between the room 1 and the exhaust chimney 8, an electric regulating valve 11 is arranged between the electric heater 2 and the pre-filter 3, and a differential pressure sensor 12 is arranged between the electric regulating valve 11 and the post-HEPA filter 6 to monitor the total resistance of the entire iodine filtration pipeline, that is, one side of the differential pressure sensor 12 is connected to the upstream of the electric regulating valve 11, and the other side of the differential pressure sensor 12 is connected to the downstream of the post-HEPA filter 6.

[0021] The pressure difference sensor 12 and the electric regulating valve 11 are connected to the controller 10 , and the fan 7 is an exhaust fan or a supply fan.

[0022] Pressure differential gauges are respectively provided at both ends of the pre-filter 3, the front HEPA filter 4, the iodine adsorber 5 and the rear HEPA filter 6 to monitor the resistance of each filter and the adsorber. The pressure differential gauge numbers correspond to P1, P2, P3 and P4, respectively, and the measured pressure values ​​are recorded as F1, F2, F3 and F4, respectively.

[0023] Among them, the total resistance of the iodine filter pipeline F12 = F1 + F2 + F3 + F4 + resistance of the electric control valve 11. The total resistance of the iodine filter pipeline needs to be balanced to keep the fan operating pressure around the rated value, and the fan can always operate in the high-efficiency and stable area. Therefore, it is necessary to adjust the opening of the electric control valve 11 in real time according to the total resistance 12, so as to keep the filter pipeline resistance stable and the fan operates in the rated high-efficiency area.

[0024] The opening of the electric regulating valve 11 is controlled and adjusted according to the air volume-resistance curve of the electric regulating valve 11, and the air volume-resistance curve of the electric regulating valve 11 is obtained by consulting the data manual of the electric regulating valve 11. In the initial operation of the iodine filtration system, since the filter element is a clean filter element and the filter equipment resistance is the initial resistance, it is necessary to interlock the electric regulating valve 11 and the controller 10 according to the total resistance pressure sensor, and increase the resistance of the electric regulating valve 11 by reducing the opening of the regulating valve, thereby increasing the pipeline resistance to the preset value, so that the fan air volume is maintained at the rated design air volume.

[0025] As the system runs, the resistance of the pre-filter 3, the pre-HEPA filter 4, the iodine adsorber 5 and the post-HEPA filter 6 will gradually increase. At this time, it is necessary to increase the opening of the electric regulating valve 11 according to the resistance value measured by the differential pressure sensor 12 to reduce the resistance of the electric regulating valve 11, thereby reducing the total resistance of the iodine filter pipeline to a preset value, so that the fan air volume is maintained at the rated design air volume.

[0026] It can be seen from the above embodiments that the balancing system capable of regulating the resistance of the iodine filter pipeline fan in real time disclosed by the present invention can ensure that during the operation of the nuclear power plant, even if the filter resistance increases and causes the resistance of the iodine filter pipeline to change, the opening of the electric regulating valve is adjusted according to the total resistance value, thereby achieving the effect of regulating the resistance of the iodine filter pipeline in real time, thereby keeping the fan operation on the iodine filter pipeline in a stable and efficient state. Not only does it extend the service life of the fan, but it also greatly improves the reliability of the system design, ensuring the safe and efficient operation of the nuclear power plant.

[0027] The system described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the technical innovation scope of the present invention.

Claims

1. A balancing system capable of regulating the resistance of a fan of an iodine filtration pipeline in real time, the system being applied to a nuclear power plant ventilation system, wherein an electric heater, a pre-filter, a pre-HEPA filter, an iodine adsorber, a post-HEPA filter and a fan are sequentially arranged between a room and an exhaust chimney, and characterized in that: An electric regulating valve is arranged between the electric heater and the pre-filter, a first differential pressure measuring device is arranged between the electric regulating valve and the post-HEPA filter to monitor the total resistance F12 of the entire iodine filtration pipeline, a sub-differential pressure measuring device is arranged on both sides of each filter and the iodine adsorber, the pressure values ​​measured by the pre-filter, the HEPA filter, the iodine adsorber and the post-HEPA filter are recorded as F1, F2, F3 and F4 respectively, the total resistance F12 of the iodine filtration pipeline = F1 + F2 + F3 + F4 + resistance of the electric regulating valve 11, the first differential pressure measuring device, each sub-differential pressure measuring device, the electric regulating valve are connected to a controller, one side of the first differential pressure measuring device is connected to the upstream of the electric regulating valve, and the other side of the first differential pressure measuring device is connected to the downstream of the post-HEPA filter, the controller adjusts the electric regulating valve according to the measurement results of the first differential pressure measuring device and the measurement results of each sub-differential pressure measuring device, so that the resistance of the iodine filtration pipeline fan remains stable, thereby ensuring that the fan operates in the rated high efficiency zone.

2. A balancing system capable of real-time regulation of iodine filtration pipeline fan resistance according to claim 1, characterized in that: The filters include the pre-filter, the HEPA filter and the post-HEPA filter.

3. A balancing system capable of real-time regulation of iodine filtration pipeline fan resistance according to claim 2, characterized in that: The opening of the electric regulating valve is adjusted according to the air volume-resistance curve of the electric regulating valve.

4. A balancing system capable of real-time regulation of iodine filtration pipeline fan resistance according to claim 3, characterized in that: The air volume-resistance curve of the electric regulating valve is obtained by querying the data sheet of the electric regulating valve.

5. A balancing system capable of real-time regulation of iodine filtration pipeline fan resistance according to claim 1, characterized in that: The fan is an exhaust fan or a supply fan.

6. A balancing system capable of real-time regulation of fan resistance of an iodine filtration pipeline according to any one of claims 1 to 5, characterized in that: The differential pressure measuring device is a differential pressure gauge or a differential pressure sensor.

7. A balancing system capable of real-time regulation of the fan resistance of an iodine filtration pipeline according to claim 6, characterized in that: The pressure difference measuring device displays the measuring result in real time.

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