Underground ventilation structure and ventilation filtration method for radioactive waste cave disposal

Abstract

The present invention discloses an underground ventilation structure for the disposal of radioactive waste in rock caves and a ventilation and filtering method. It comprises a mechanical fan room, a filter fan room and a natural ventilation duct, wherein the mechanical fan room, the filter fan room and the natural ventilation duct are arranged in the same excavated cavern, the mechanical fan room is arranged at the rear side of the air inlet tunnel, the filter fan room is located at the rear side of the mechanical fan room, and the filter fan room is arranged at the front side of the exhaust tunnel; the natural ventilation duct is located in the upper half of the cavern and is located above the mechanical fan room and the filter fan room, and a fan is arranged in the mechanical fan room. The structure proposed by the present invention realizes the integration of natural ventilation, mechanical ventilation, filter ventilation and building (structure) in the same excavated cavern by utilizing the spatial height difference of local expansion and the integration of front and back sequence positions, thereby minimizing the construction scale and excavation size of the underground cavern group, and obtaining better technical and economic performance.

Description

Technical Field

[0001] The invention belongs to the technical field of rock cave disposal engineering for low and medium radioactive level solid waste, and in particular relates to an underground ventilation structure for rock cave disposal of radioactive waste and a ventilation filtering method. Background Art

[0002] The cave disposal project for low- and medium-level radioactive solid waste is set up in an underground closed space, and there are personnel activities in the underground cave system during operation. In order to ensure the safety of cave disposal and personnel operation, an underground ventilation system should be set up. The system needs to meet the following requirements: 1. The concentration requirements of harmful gases in the air during operation; 2. Air humidity requirements; 3. Radioactive aerosol filtration and treatment requirements; 4. Green energy saving and environmental protection requirements. Therefore, the application scenarios of the ventilation system in the cave need to meet the three main functional requirements of natural ventilation, mechanical ventilation and filtration and disposal.

[0003] The above-mentioned multiple functions are usually solved by setting up three independent air ducts, but the sizes of the mechanical fan room and the filter fan room are relatively large. If independent air ducts are set up to place the mechanical fan room and the filter fan room, the excavation size and construction scale of the underground cavern group will be relatively large, which is not conducive to the long-term surrounding rock stability of the underground cavern group and has poor technical and economic performance. Summary of the invention

[0004] The present invention makes full use of the spatial effect of underground caverns to integrate the natural ventilation duct, mechanical ventilation duct and its equipment, and radioactive gas filtering equipment system in a single cavern, thereby overcoming the deficiency that the existing single ventilation technology scheme cannot meet the ventilation, filtering and energy-saving requirements in the disposal caverns, and provides an underground ventilation structure and ventilation filtering method for the disposal of radioactive waste caverns, realizing the effective combination of natural ventilation, mechanical ventilation and filtering systems.

[0005] The technical solution adopted by the present invention is: an underground ventilation structure for radioactive waste cave disposal, including a mechanical fan room, a filter fan room and a natural ventilation duct, wherein the mechanical fan room, the filter fan room and the natural ventilation duct are arranged in the same excavated cavern, the mechanical fan room is arranged at the rear side of the air inlet tunnel, the filter fan room is located at the rear side of the mechanical fan room, and the filter fan room is arranged in front of the exhaust tunnel; the natural air duct is located in the upper half of the excavated cavern and is located above the mechanical fan room and the filter fan room, and a mechanical fan is provided in the mechanical fan room.

[0006] In a further preferred structure, the natural ventilation duct includes a first natural duct and a second natural duct, wherein the first natural duct is located at the upper part of the mechanical fan room, and the second natural duct is located at the upper part of the filter fan room.

[0007] A further preferred structure is that the inlet and outlet of the mechanical fan room are provided with mechanical ventilation valves, the inlet and outlet of the filtering fan room are provided with filtering ventilation valves, the inlet of the first natural air duct is provided with a first natural ventilation valve, and the inlet of the second natural air duct is provided with a second natural ventilation valve.

[0008] A further preferred structure is that a first reinforced concrete partition wall is provided on the upper part of the mechanical fan room inlet, the first natural ventilation air valve is arranged in the first reinforced concrete partition wall, the mechanical fan room air valve is arranged at the lower part of the first reinforced concrete partition wall, and a mechanical fan room enclosed door is provided in the middle of the first reinforced concrete partition wall.

[0009] A further preferred structure is that a second reinforced concrete partition wall is provided on the upper part of the filtering fan room, the second natural ventilation air valve is arranged in the second reinforced concrete partition wall, the filtering ventilation air valve is arranged at the lower part of the second reinforced concrete partition wall, and a filtering fan room enclosed door is provided in the middle of the lower part of the second reinforced concrete partition wall.

[0010] In a further preferred structure, the front side of the filtering fan room is connected in sequence to the connecting section, the mechanical fan room, the air inlet tunnel expansion section and the air inlet tunnel.

[0011] In a further preferred structure, the rear side of the filter fan room is connected to the exhaust tunnel expansion section and the exhaust tunnel in sequence.

[0012] A ventilation and filtration method for an underground ventilation structure for radioactive waste cave disposal, comprising the following steps:

[0013] (1) Natural ventilation: In winter, the temperature inside the cave is higher than the outside temperature, the air density is low, and the air inside the cave escapes from the exhaust tunnel through the air inlet tunnel;

[0014] (2) Mechanical ventilation: In summer, the temperature inside the cave is lower than the outside temperature. The outside air flows back into the cave from the exhaust tunnel, and then passes through the mechanical fan room to filter the air inside the cave before being discharged.

[0015] (3) Filtration and ventilation: When radioactive aerosols are present inside the cave due to the disposal of a large amount of solid waste, and it is detected that the radioactive aerosols in the air inside the cave exceed the standard, the air inside the cave is filtered and discharged through the filter fan room.

[0016] Specifically, the following steps are included: (1) natural ventilation: close the mechanical ventilation air valve and the filter ventilation air valve, open the first natural ventilation air valve on the upper part of the mechanical fan room and the second natural ventilation air valve on the upper part of the filter fan room; close the airtight door of the mechanical fan room and the airtight door of the filter fan room, so that air is discharged from the inside of the disposal cave through the air inlet tunnel, the expanded section of the air inlet tunnel, the first natural air duct on the upper part of the mechanical fan room, the second natural air duct on the upper part of the filter fan room, the expanded section of the exhaust tunnel and the exhaust tunnel to the outside of the exhaust port;

[0017] (2) Mechanical ventilation: Close the first natural ventilation air valve and filter ventilation air valve on the top of the mechanical fan room, and open the mechanical ventilation air valve and the second natural ventilation air valve in front of the filter fan room; open the sealed door of the mechanical fan room and close the sealed door of the filter fan room to allow air to be discharged from the inside of the disposal cavern through the air inlet tunnel, the expanded section of the air inlet tunnel, the mechanical fan room, the connecting section, the second natural air duct on the top of the filter fan room, the expanded section of the exhaust tunnel, and the exhaust tunnel;

[0018] (3) Filter ventilation: Close the mechanical ventilation valve and the second natural ventilation valve on the top of the filter fan room, open the first natural ventilation valve and filter ventilation valve on the top of the mechanical fan room, close the sealed door of the mechanical fan room, open the sealed door of the filter fan room, and allow air to be discharged from the inside of the disposal cave through the air inlet tunnel, the expanded section of the air inlet tunnel, the first natural air duct on the top of the mechanical fan room, the connecting section, the filter fan room, the expanded section of the exhaust tunnel and the exhaust tunnel.

[0019] The beneficial effects of the present invention are as follows: through the opening and closing combination of the machine room and the air valve under different operating conditions, the possible contamination of the personnel operation passage and the mechanical equipment inside the mechanical fan room by toxic gases and radioactive aerosols is avoided, and the toxic gases and radioactive aerosols can be treated in the filter fan room to achieve emission standards.

[0020] At the same time, the structural mechanical fan room and the filter fan room are arranged front and back, which can minimize the cross-sectional size and scale of the cave, improve the space utilization and natural stability of the cave, thereby reducing the difficulty of design and construction and saving engineering investment.

[0021] The structure proposed in the invention realizes the integration of air ducts and building (structure) structures of natural ventilation, mechanical ventilation and filtration systems in the cave space of the same air duct by utilizing the spatial height difference of local excavation and the integration of front and back sequence positions, thereby minimizing the scale and size of the underground cavern group and obtaining better technical and economic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural cross-sectional view of the present invention;

[0023] Figure 2 for Figure 1Middle AA section;

[0024] Figure 3 for Figure 1 Middle BB cross-section.

[0025] In the figure: 1-air inlet tunnel; 2-enlarged section of air inlet tunnel; 3-first natural air duct; 4-connecting section; 5-second natural air duct; 6-enlarged section of exhaust tunnel; 7-exhaust tunnel; 8-mechanical fan room; 9-filter fan room; 10-first reinforced concrete partition wall; 11-second reinforced concrete partition wall; 12-first natural ventilation air valve; 13-second natural ventilation air valve; 14-mechanical ventilation air valve; 15-filter ventilation air valve; 16-mechanical fan room closed door; 17-filter fan room closed door. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but they do not constitute a limitation on the present invention.

[0027] like Figure 1 As shown, the present invention includes a mechanical fan room 8, a connecting section 4, a filter fan room 9 and a natural ventilation duct, and the mechanical fan room 8, the filter fan room 9 and the natural ventilation duct are arranged in the same excavated cave. The mechanical fan room 8 is arranged at the rear side of the air inlet tunnel 1, the filter fan room 9 is located at the rear side of the mechanical fan room 8, and the filter fan room 9 is arranged at the front side of the exhaust tunnel 7; the natural ventilation duct is located in the upper half of the cave, and is located above the mechanical fan room 8 and the filter fan room 9. The mechanical fan room 8 is provided with a mechanical ventilation air valve 14, and the filter fan room 9 is provided with a filter ventilation air valve 15. The natural ventilation duct includes a first natural air duct 3 and a second natural air duct 5, the first natural air duct 3 is located above the mechanical fan room 8, and the second natural air duct 5 is located above the filter fan room 9. The inlet of the mechanical fan room 8 is provided with a mechanical ventilation air valve 14, the inlet of the filtering fan room 9 is provided with a filtering ventilation air valve 15, the inlet of the first natural air duct 3 is provided with a first natural ventilation air valve 12, and the inlet of the second natural air duct 5 is provided with a second natural ventilation air valve 13.

[0028] like Figure 2 As shown, a first reinforced concrete partition wall 10 is provided above the inlet of the mechanical fan room 8, the first natural ventilation air valve 12 is provided inside the first reinforced concrete partition wall 10, the mechanical ventilation air valve 14 is provided at the lower part of the first reinforced concrete partition wall 10, and a mechanical fan room enclosed door 16 is provided in the middle of the lower part of the first reinforced concrete partition wall 10.

[0029] like Figure 3As shown, a second reinforced concrete partition wall 11 is provided at the upper part of the inlet of the filtering fan room 9, the second natural ventilation air valve 13 is provided at the upper part of the second natural ventilation duct structure, the filtering ventilation air valve 15 is provided at the lower part of the second reinforced concrete partition wall 11, and a filtering fan room enclosed door 16 is provided in the middle of the lower part of the second reinforced concrete partition wall 11.

[0030] like Figure 1 As shown, the front side of the mechanical fan room 8 is connected to the air inlet tunnel expansion section 2 and the air inlet tunnel 1 in sequence. The rear side of the filter fan room 9 is connected to the exhaust tunnel expansion section 6 and the exhaust tunnel 7 in sequence.

[0031] Reference Figure 1 , Figure 2 and Figure 3 , this ventilation arrangement mainly considers three situations:

[0032] 1. Natural ventilation: In winter, the temperature inside the cave is higher than the outside temperature, the air density is low, and the air inside the cave escapes from the exhaust tunnel through the air inlet tunnel, forming a natural ventilation effect;

[0033] 2. Mechanical ventilation: In summer, the temperature inside the cave is lower than the outside temperature, which will cause the outside air to flow back into the cave from the exhaust tunnel. At this time, mechanical ventilation is needed to exhaust the air inside the cave;

[0034] 3. Filtration and ventilation: When radioactive aerosols are present inside the cave due to the disposal of a large amount of solid waste, and it is detected that the radioactive aerosols in the air inside the cave exceed the standard, it is necessary to start the filtration system inside the cave to filter and discharge the air inside the cave.

[0035] Specifically, the present invention reasonably arranges the positions of the mechanical fan room 8 and the filter fan room 9, and controls the air flow channel through air valves at different positions, thus realizing three kinds of air duct ventilation very well. Through this design structure, the ventilation system can meet the following requirements:

[0036] (1) Natural ventilation: When the temperature inside the cave is higher than that of the outside air, natural ventilation can be used by utilizing the air buoyancy effect. At this time, the air valve of the natural air duct is opened, the air valve of the mechanical ventilation and the air valve of the filtered ventilation are closed, and no mechanical ventilation is operated to achieve energy-saving operation.

[0037] (2) Mechanical ventilation: When the air temperature inside the cave is lower than the outside air temperature, mechanical forced ventilation can be used; at this time, the first natural ventilation air valve and the air valve in front of the filter fan room are closed, the second natural ventilation air valve is opened, and the mechanical fan room is in operation.

[0038] (3) Filtration ventilation: When the radioactive aerosol content in the disposal cave exceeds the standard, the filtration ventilation operation mode shall be adopted; at this time, the first natural ventilation air valve is opened, the second natural ventilation air valve is closed, the mechanical ventilation air valve is closed, the inlet and outlet air valves of the filtration fan room are opened, and the filtration ventilation system operates normally. Toxic and harmful gases are discharged to the external environment after being treated by the filtration system and meeting the standards.

[0039] The main working forms of the ventilation and filtration system of the present invention are:

[0040] (1) Natural ventilation: Close the mechanical ventilation air valve 14 and the filter ventilation air valve 15, open the first natural ventilation air valve 12 on the upper part of the mechanical fan room and the second natural ventilation air valve 13 on the upper part of the filter fan room; close the mechanical fan room airtight door 16 and the filter fan room airtight door 17, so that the air from the inside of the disposal cave passes through the air inlet tunnel 1, the air inlet tunnel expansion section 2, the first natural air duct 3 on the upper part of the mechanical fan room, the second natural air duct 5 on the upper part of the filter fan room, the exhaust tunnel expansion section 6 and the exhaust tunnel 7 to the exhaust outlet;

[0041] (2) Mechanical ventilation: Close the first natural ventilation air valve 12 and the filter ventilation air valve 15 on the upper part of the mechanical fan room, and open the mechanical ventilation air valve 14 and the second natural ventilation air valve 13 in front of the filter fan room; open the airtight door 16 of the mechanical fan room and close the airtight door 17 of the filter fan room, so that the air is discharged from the inside of the disposal cavern through the air inlet tunnel 1, the air inlet tunnel expansion section 2, the mechanical fan room 8, the connecting section 4, the second natural air duct 5 on the upper part of the filter fan room, the exhaust tunnel expansion section 6 and the exhaust tunnel 7;

[0042] (3) Filter ventilation: close the mechanical ventilation air valve 14 and the second natural ventilation air valve 13 on the upper part of the filter fan room 9, open the first natural ventilation air valve 12 and the filter ventilation air valve 15 on the upper part of the mechanical fan room, close the mechanical fan room sealed door 16, open the filter fan room sealed door 17, so that the air is discharged from the inside of the disposal cave through the air inlet tunnel 1, the air inlet tunnel expansion section 2, the first natural air duct 3 on the upper part of the mechanical fan room, the connecting section 4, the filter fan room 9, the exhaust tunnel expansion section 6 and the exhaust tunnel 7.

[0043] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. An underground ventilation structure for radioactive waste cave disposal, Features: It includes a mechanical fan room, a filter fan room and a natural ventilation duct, wherein the mechanical fan room, the filter fan room and the natural ventilation duct are arranged in the same excavated cavern, the mechanical fan room is arranged at the rear side of the air inlet tunnel, the filter fan room is located at the rear side of the mechanical fan room, and the filter fan room is arranged in front of the exhaust tunnel; The natural ventilation duct is located in the upper half of the excavated cavern, and is located above the mechanical fan room and the filter fan room, and a mechanical fan is provided in the mechanical fan room; the natural ventilation duct includes a first natural ventilation duct and a second natural ventilation duct, the first natural ventilation duct is located above the mechanical fan room, and the second natural ventilation duct is located above the filter fan room; the inlet and outlet of the mechanical fan room are provided with mechanical ventilation valves, and the inlet and outlet of the filter fan room are provided with filter ventilation valves, the inlet of the first natural ventilation duct is provided with a first natural ventilation valve, and the inlet of the second natural ventilation duct is provided with a second natural ventilation valve; the front side of the filter fan room is connected to the connecting section, the mechanical fan room, the expanded section of the air inlet tunnel and the air inlet tunnel in sequence; the rear side of the filter fan room is connected to the expanded section of the exhaust tunnel and the exhaust tunnel in sequence; The ventilation and filtration method for the underground ventilation structure for the disposal of radioactive waste in rock caves comprises the following steps: (1) Natural ventilation: In winter, the temperature inside the cave is higher than the outside temperature, the air density is low, and the air inside the cave escapes from the exhaust tunnel through the air inlet tunnel; (2) Mechanical ventilation: In summer, the temperature inside the cave is lower than the outside temperature. The outside air flows back into the cave from the exhaust tunnel, and then passes through the mechanical fan room to filter the air inside the cave before being discharged. (3) Filtration and ventilation: When radioactive aerosols are present inside the cave due to the disposal of a large amount of solid waste, and it is detected that the radioactive aerosols in the air inside the cave exceed the standard, the air inside the cave is filtered and discharged through the filter fan room.

2. The underground ventilation structure for radioactive waste cave disposal according to claim 1, Features: A first reinforced concrete partition wall is provided above the entrance of the mechanical fan room, the first natural ventilation air valve is arranged in the first reinforced concrete partition wall, the mechanical fan room air valve is arranged at the bottom of the first reinforced concrete partition wall, and a mechanical fan room closed door is provided in the middle of the first reinforced concrete partition wall.

3. The underground ventilation structure for radioactive waste cave disposal according to claim 1, Features: A second reinforced concrete partition wall is provided on the upper part of the filtering fan room, the second natural ventilation air valve is arranged in the second reinforced concrete partition wall, the filtering ventilation air valve is arranged at the lower part of the second reinforced concrete partition wall, and a closed door of the filtering fan room is provided in the middle of the lower part of the second reinforced concrete partition wall.

4. A ventilation and filtration method for underground ventilation structures for radioactive waste cave disposal according to claim 1, Features: The following steps are involved: (1) Natural ventilation: Close the mechanical ventilation air valve and the filter ventilation air valve, open the first natural ventilation air valve on the upper part of the mechanical fan room and the second natural ventilation air valve on the upper part of the filter fan room; close the airtight door of the mechanical fan room and the airtight door of the filter fan room, so that the air from the inside of the disposal cave passes through the air inlet tunnel, the expanded section of the air inlet tunnel, the first natural ventilation duct on the upper part of the mechanical fan room, the second natural ventilation duct on the upper part of the filter fan room, the expanded section of the exhaust tunnel and the exhaust tunnel to the exhaust outlet; (2) Mechanical ventilation: Close the first natural ventilation air valve and filter ventilation air valve on the top of the mechanical fan room, and open the mechanical ventilation air valve and the second natural ventilation air valve in front of the filter fan room; open the sealed door of the mechanical fan room and close the sealed door of the filter fan room to allow air to be discharged from the inside of the disposal cavern through the air inlet tunnel, the expanded section of the air inlet tunnel, the mechanical fan room, the connecting section, the second natural ventilation air duct on the top of the filter fan room, the expanded section of the exhaust tunnel and the exhaust tunnel; (3) Filter ventilation: Close the mechanical ventilation valve and the second natural ventilation valve on the top of the filter fan room, open the first natural ventilation valve and filter ventilation valve on the top of the mechanical fan room, close the sealed door of the mechanical fan room, open the sealed door of the filter fan room, and allow the air to be discharged from the inside of the disposal cave through the air inlet tunnel, the expanded section of the air inlet tunnel, the first natural ventilation duct on the top of the mechanical fan room, the connecting section, the filter fan room, the expanded section of the exhaust tunnel and the exhaust tunnel.

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