Pressurizing, oxygenating and ventilating system and method for high-altitude construction tunnel

Abstract

The invention discloses a high-altitude construction tunnel pressurization, oxygenation and ventilation system and method.The system comprises a tunnel opening pressurization chamber, an automatic air door, a hard air pipe and an exhaust pipe, the tunnel opening pressurization chamber is arranged at a tunnel opening and is a closed space, and the front end of the tunnel opening pressurization chamber is connected with a tunnel and communicated with the interior of the tunnel opening; the right side, close to the rear end, of the pressurizing chamber extends rightwards to form a right channel; the left side extends leftwards to form a left channel; two air doors are arranged in each of the right channel and the left channel in a left-right spaced mode, and the two air doors cannot be opened or closed at the same time in each channel; the automatic air door is arranged in the tunnel hole, and the space at the rear end of the automatic air door is communicated with the pressurizing chamber; an air supply pipe is communicated in the operation space; the exhaust pipe is used for exhausting excessive gas in the pressurizing chamber to the outside; the pressure difference between the pumping chamber and the working space is maintained within a set range. According to the system, gradient pressure distribution in a tunnel is realized by arranging a portal pressurizing chamber at a tunnel portal and linking the portal pressurizing chamber with an air door in the tunnel.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel construction, and in particular relates to a pressurized and oxygenated ventilation system and method for high-altitude construction tunnels. Background Art

[0002] The harsh natural environment of high-altitude construction tunnels, such as low pressure, low temperature, and low oxygen concentration, brings more severe challenges to the construction of tunnels. In particular, the problem of hypoxia. Although the volume concentration of oxygen is the same at different altitudes, the oxygen partial pressure decreases with the increase of altitude, which may lead to insufficient oxygen supply for construction workers. Solving the problem of hypoxia by pressurization is a common method.

[0003] At present, the commonly used methods are as follows: First, local pressurization of the front cavity face is achieved through the cooperation of the pressurized power system, the pressure regulating system and the sealing system in the tunnel. However, this method is not easy to promote and apply because the cost of a single pressurized power system is high and it has certain safety risks. Second, the tunnel is divided into a wind supply area and a pressurized area. The outlet of the fan in the wind supply area conveys the airflow to the inlet of the fan in the pressurized area through the air duct, and the problem of insufficient ventilation over long distances is solved by fan relay. However, this method still cannot solve the problem of low pressure on the face. Summary of the invention

[0004] The purpose of the present invention is to provide a pressurized and oxygenated ventilation system and method for high-altitude construction tunnels, which realizes the gradient pressure distribution inside the tunnel by setting up a pressurized chamber at the tunnel entrance and linking it with the air doors in the tunnel.

[0005] The present invention adopts the following technical scheme: a pressurized and oxygenated ventilation system for a high-altitude construction tunnel, which includes a tunnel entrance pressurized chamber, an automatic damper, a hard air duct and an exhaust duct, wherein:

[0006] The entrance booster chamber is set at the tunnel entrance. It is a closed space, with the front end connected to the tunnel and connected to the inside of the tunnel. Its left-right width is greater than the left-right span of the tunnel. The entrance booster chamber maintains a set pressure.

[0007] The right side of the boost chamber near the rear end extends to the right to form a right channel; the left side extends to the left to form a left channel; two dampers are arranged in the right channel and the left channel at intervals on the left and right, and in each channel, the two dampers cannot be opened or closed at the same time;

[0008] The automatic damper is set in the tunnel, and forms a closed working space with the front tunnel face; the space at the rear end is connected to the booster chamber; the upper part of the automatic damper is provided with an automatic pressure relief multi-leaf wind window; the working space is connected with an air supply pipe, which continuously supplies air to the working space to maintain the working space under high pressure; when the pressure value is greater than the set pressure, the gas in the working space is discharged into the booster chamber through the wind window;

[0009] The exhaust duct has a front section located in the cave entrance booster chamber, and a rear end passing through the rear side wall of the cave entrance booster chamber and located outdoors; the exhaust duct is used to discharge excess gas in the booster chamber to the outdoors; and to keep the pressure difference between the booster chamber and the working space within a set range.

[0010] Furthermore, a first drainage ditch is excavated on the left or right side of the tunnel, and the direction of the first drainage ditch is consistent with the direction of the tunnel; a first water collection pit is excavated in the direction of the first drainage ditch in the working space and close to the automatic damper, and the depth of the first water collection pit is lower than the lower end of the automatic damper;

[0011] A second drainage ditch is excavated in the cave entrance booster chamber and on the side where the first drainage ditch is located. The front end of the second drainage ditch is connected to the bottom of the first sump through a first connecting pipe. The first connecting pipe includes a vertical section connected to the second drainage ditch and a horizontal section connected to the first sump, and the horizontal section is located below the ground.

[0012] The rear end of the second drainage ditch discharges the sewage to the outside of the cave entrance booster chamber through the second connecting pipe.

[0013] Furthermore, a second sump is dug in the cave entrance booster chamber and located at the side wall. The second sump is used to receive sewage discharged from the second drainage ditch. The bottom of the second sump is connected to the horizontal section of the second connecting pipe, and the horizontal section is connected to a vertical section; the horizontal section is located in the soil below the side wall of one side of the cave entrance booster chamber and spans the side wall; the vertical section is vertically upward, and its lower end is connected to the outlet of the horizontal section, and the upper end is used to connect to the sewage receiving device.

[0014] Furthermore, the height of the first connecting pipe is greater than the height of the water column of the pressure difference on both sides of the automatic damper in the tunnel, and the height of the second connecting pipe is greater than the height of the water column of the pressure difference on both sides of the side wall of the cave entrance booster chamber.

[0015] Furthermore, a rotating slag discharge bucket is arranged on the side wall at the rear end of the tunnel entrance booster chamber, and the rotating slag discharge bucket comprises a cylindrical shell, which is embedded in the side wall and is formed by a plurality of arc-shaped plates connected end to end, and both ends of the cylindrical shell are closed by circular end plates; an opening is opened on the cylindrical shell; a rotating shaft is coaxially penetrated at the center axis of the cylindrical shell, and both ends of the rotating shaft pass through the circular end plates; a plurality of partition plates are arranged at intervals around the rotating shaft, and the length direction of each partition plate is consistent with the direction of the rotating shaft, and the width direction extends to the inner wall of the cylindrical shell, and an independent space is formed between two circumferentially adjacent partition plates for receiving the slag transported out of the tunnel, which is driven by the rotating shaft to be discharged to the outside of the tunnel entrance booster chamber.

[0016] Furthermore, the air supply duct includes a hard air duct, the front end of which passes through the hole booster chamber and extends through the automatic damper. A soft air duct is axially connected to the front end of the hard air duct and is located in the working space; the rear end of the hard air duct passes through the rear side wall of the hole booster chamber and is located outdoors.

[0017] Furthermore, each damper in the right channel and the left channel, as well as the automatic damper include a left sealing plate, a right sealing plate, an upper sealing plate and a split door plate. The left sealing plate, the split door plate and the right sealing plate are all vertically arranged and arranged in parallel from left to right; the upper sealing plate is connected to the upper ends of the left sealing plate, the split door plate and the right sealing plate, and an automatic pressure relief multi-leaf damper is provided on the upper sealing plate; a pedestrian door panel is provided at the lower left end of the split door plate.

[0018] The present invention also discloses a ventilation method for a pressurized and oxygenated ventilation system of a high-altitude construction tunnel, the ventilation method comprising the following steps:

[0019] Step 1: Set up a cave entrance booster chamber, maintain a certain pressure value in the cave entrance booster chamber, and the air supply pipe continuously supplies air into the working space to maintain the pressure near the face; when the pressure near the face is too high, the automatic pressure relief multi-leaf wind window on the automatic air door opens to discharge the excess gas into the cave entrance booster chamber; when the pressure in the cave entrance booster chamber is too high and the pressure value between the cave entrance and the working space is too high, the exhaust pipe discharges the excess gas in the cave entrance booster chamber to the outside;

[0020] Step 2: wastewater from the face construction process is discharged into the first drainage ditch, and then into the first sump in turn. The wastewater in the first sump flows into the second drainage ditch through the first connecting pipe, and then into the second sump. The wastewater in the second sump is discharged to the outside through the second connecting pipe, thus completing the non-pressure relief drainage.

[0021] Step 3: The soil during the face construction process is transported to the tunnel entrance booster chamber and transported out by rotating the slag dump bucket;

[0022] Step 4: When the vehicle passes through the outer dampers of the left channel and the right channel, the outer damper's automatic pressure relief multi-leaf damper window opens. When the pressure inside and outside the outer damper is balanced, the outer damper is opened, the vehicle passes through the outer damper, the two outer dampers are closed, and the automatic pressure relief multi-leaf damper window of the inner damper is opened. When the pressure inside and outside the inner damper is balanced, the inner damper is opened, the vehicle enters the cave entrance pressurization chamber, and the inner damper is closed;

[0023] When a vehicle passes through the automatic damper, the automatic pressure relief multi-leaf windshield of the automatic damper opens to discharge the gas in the working space. When the air pressure before and after the automatic damper is balanced, the automatic damper opens and the vehicle passes through the automatic damper.

[0024] The beneficial effects of the present invention are: 1. By setting up a tunnel portal booster chamber and automatic dampers in the tunnel, the air pressure at the face is maintained near the design requirements. There is no need to set up a separate oxygen supply system. The oxygen partial pressure is increased by boosting to meet the oxygen supply; relying on the exhaust pipe and the automatic dampers in the tunnel to achieve gradient pressure distribution inside the tunnel, avoid the phenomenon of damper damage caused by excessive pressure difference, and also achieve the effect of reducing the exhaust wind speed. 2. By setting up a sump and connecting pipe for drainage, the problem of pressure relief caused by drainage during the pressurization process is solved, thereby maintaining the internal air pressure near the face stable. 3. A rotating slag dump is embedded in the side wall. After the excavated rock and soil are sent to the portal booster chamber, they are sent to the outside through the rotating slag dump. During the process, the indoor pressure remains stable and the entire system maintains a stable working state. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of a pressurized and oxygenated ventilation system for high-altitude construction tunnels;

[0026] Figure 2 This is a schematic diagram of the structure of the drainage ditch;

[0027] 2a is the enlarged view of point C;

[0028] 2b is a schematic diagram of the DD section;

[0029] Figure 3 It is a structural schematic diagram of a rotary slag dump bucket;

[0030] 3a is a schematic diagram of the structure of the cylindrical shell;

[0031] 3b is a schematic diagram of the EE cross section;

[0032] Figure 4 This is a schematic diagram of the tunnel entrance exhaust duct;

[0033] Figure 5 It is a structural schematic diagram of the automatic damper;

[0034] Among them: 1. Blower; 2. Hard air duct; 3. Soft air duct; 4. Differential pressure sensor; 5. Pressure sensor; 6. First infrared laser sensor; 7. Second infrared laser sensor; 8. Automatic damper in the tunnel; 9. Exhaust duct; 10. Rotating slag dump bucket; 11. Automatic damper at the first entrance; 12. Automatic damper at the second entrance; 13. Automatic damper at the third entrance; 14. Automatic damper at the fourth entrance; 15. Portal booster chamber; 16. Vehicle; 17. Bypass pipe; 18. Bypass valve; 19. Drain ditch; 20. Sump; 21. Connecting pipe; 22. Round end plate; 23. Rotating shaft; 24. Partition plate; 25. Arc plate; 26. Automatic multi-leaf regulating valve; 27. Wind hood; 28. Left sealing plate; 29. ​​Right sealing plate; 30. Upper sealing plate; 31. Double door plate; 32. Pedestrian door plate; 33. Automatic pressure relief multi-leaf windshield. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] The present invention discloses a pressurized and oxygenated ventilation system for high altitude construction tunnels. Figure 1 The structure shown includes a hole pressurizing chamber 15, an automatic damper 8, a hard air duct 2 and an exhaust duct 9, wherein:

[0037] The entrance booster chamber 15 is arranged at the tunnel entrance, which is a closed space, the front end of which is connected to the tunnel and communicates with the inside of the tunnel; its left-right width is greater than the left-right span of the tunnel; the entrance booster chamber 15 maintains a set pressure;

[0038] The right side of the boost chamber 15 near the rear end extends to the right to form a right channel; the left side extends to the left to form a left channel; two dampers are arranged in the right channel and the left channel at intervals, and in each channel, the two dampers cannot be opened or closed at the same time; the first entrance automatic damper 12 and the second entrance automatic damper 11 are arranged in intervals from right to left in the right channel, and the first entrance automatic damper 12 and the second entrance automatic damper 11 cannot be opened or closed at the same time; the third entrance automatic damper 13 and the fourth entrance automatic damper 14 are arranged in intervals from left to right in the left channel. Two automatic dampers in the same channel cannot be opened at the same time.

[0039] like Figure 5 As shown, the automatic damper 8 is arranged in the tunnel hole, and a closed working space is formed between it and the front tunnel face; the space at the rear end thereof is connected with the booster chamber 15; an openable and closable wind window 33 is arranged on the upper part of the automatic damper 8; an air supply pipe is connected in the working space, and the air supply pipe continuously supplies air into the working space, so that the working space is maintained at a high pressure; when the pressure value is greater than the set pressure, the gas in the working space is discharged into the booster chamber 15 through the wind window 33;

[0040] like Figure 4 As shown, the exhaust pipe 9 has its front section located in the cave entrance booster chamber 15, and its rear end passes through the rear side wall of the cave entrance booster chamber 15 and is located outdoors; the exhaust pipe 9 is used to discharge excess gas in the booster chamber 15 to the outdoors; and to keep the pressure difference between the booster chamber 15 and the working space within the set range. The front section of the exhaust pipe 9 is a horizontal pipe, on which an automatic multi-leaf regulating valve 26 is installed. The rear end of the exhaust pipe 9 is provided with a vertical section, which is vertically upward, and a wind cap 27 is installed on the end air outlet of the vertical section. The opening degree of the automatic multi-leaf regulating valve 26 is mainly adjusted according to the second pressure sensor 5B of the cave entrance booster chamber 15. The opening degree of the automatic pressure relief multi-leaf wind window 33 on the automatic damper 8 in the tunnel is determined by the first pressure sensor 5A and the second pressure sensor 5B near the face. If the pressure difference between the pressure near the face and the pressure in the tunnel entrance booster chamber 15 is too large, and the pressure near the face is large, the opening degree of the automatic pressure relief multi-leaf wind window 33 on the automatic damper 8 in the tunnel becomes larger, reducing the pressure near the face, and reducing the pressure difference between the working space in the tunnel and the tunnel entrance booster chamber 15. The gradient pressure distribution before and after the automatic damper 8 in the tunnel can be achieved, avoiding damage to the damper and other devices due to excessive pressure difference, and at the same time avoiding injuries and potential dangers to personnel caused by excessive pressure difference.

[0041] Each damper in the right channel and the left channel, as well as the automatic damper 8, comprises a left sealing plate 28, a right sealing plate 29, an upper sealing plate 30 and a split door plate 31. The left sealing plate 28, the split door plate 31 and the right sealing plate 29 are all vertically arranged and arranged in parallel from left to right. The upper sealing plate 30 is connected to the upper ends of the left sealing plate 28, the split door plate 31 and the right sealing plate 29, and an automatic pressure relief multi-leaf damper 33 is provided on the upper sealing plate 30. A pedestrian door plate 32 is provided at the lower left end of the split door plate 31. The multi-leaf dampers 33 of each damper in the right channel and the left channel are in a normally closed state.

[0042] The first infrared laser sensor 7 and the second infrared laser sensor 6 are respectively arranged in front and behind each damper in the right channel and the automatic damper 8. When the second infrared laser sensor 6 outside the first entrance automatic damper 12 and the third entrance automatic damper 13 senses an incoming vehicle, the automatic pressure relief multi-leaf damper 33 on the corresponding automatic damper is automatically opened first, and the air pressure inside and outside the automatic damper is balanced, and the split door panel 31 is automatically opened. After the first infrared laser sensor 7 senses the vehicle passing, the split door panel 31 is closed. When the infrared laser sensor 6 in front of the second automatic damper senses an incoming vehicle, the automatic pressure relief multi-leaf damper 33 on the second automatic damper 11 and the fourth automatic damper 14 is opened, and the air pressure on both sides is balanced, and the split door panel 31 on the corresponding automatic damper is automatically opened. After the second infrared laser sensor 7 senses the vehicle passing, the split door panel 31 on the corresponding automatic damper is closed.

[0043] like Figure 2 As shown in 2a and 2b, a first drainage ditch 19 is excavated on the left or right side of the tunnel, and the direction of the first drainage ditch 19 is consistent with the direction of the tunnel; a first water collection pit 20A is excavated in the direction of the first drainage ditch 19 in the working space and near the automatic damper 8, and the depth of the first water collection pit 20A is lower than the lower end of the automatic damper 8;

[0044] A second drainage ditch is excavated in the cave entrance booster chamber 15 and located on the side where the first drainage ditch 19 is located. The front end of the second drainage ditch is connected to the bottom of the first sump 20A through a first connecting pipe 21A. The first connecting pipe 21A includes a vertical section connected to the second drainage ditch and a horizontal section connected to the first sump 20A, and the horizontal section is located below the ground.

[0045] The rear end of the second drainage ditch discharges the sewage to the outside of the cave entrance booster chamber 15 through the second connecting pipe.

[0046] A second sump 20B is dug in the cave entrance booster chamber 15 and located at the side wall. The second sump 20B is used to receive sewage discharged from the second drainage ditch. The bottom of the second sump 20B is connected to the horizontal section of the second connecting pipe, and the horizontal section is connected to a vertical section; the horizontal section is located in the soil below the side wall on one side of the cave entrance booster chamber 15 and spans the side wall; the vertical section is vertically upward, and its lower end is connected to the outlet of the horizontal section, and the upper end is used to connect to the sewage receiving device.

[0047] The height of the first connecting pipe 21A is greater than the height of the water column of the pressure difference on both sides of the automatic damper 8 in the tunnel, and the height of the second connecting pipe 21B is greater than the height of the water column of the pressure difference on both sides of the side wall of the cave entrance booster chamber 15.

[0048] As shown in 3a and 3b in 3, a rotating slag dump 10 is arranged on the side wall at the rear end of the tunnel booster chamber 15. The rotating slag dump 10 includes a cylindrical shell, which is embedded in the side wall and is surrounded by a plurality of arc plates 25 connected end to end. Both ends of the cylindrical shell are closed by a circular end plate 22. An opening is opened on the cylindrical shell. A rotating shaft 23 is coaxially penetrated at the center axis of the cylindrical shell, and both ends of the rotating shaft 23 pass through the circular end plate 22. A plurality of partition plates 24 are arranged around the rotating shaft 23 at intervals. The length direction of each partition plate 24 is consistent with the direction of the rotating shaft 23, and the width direction extends to the inner wall of the cylindrical shell. An independent space is formed between two adjacent partition plates 24 in an annular direction, which is used to receive the slag transported out of the tunnel and discharged to the outside of the tunnel booster chamber 15 by the rotating shaft 23. The arc plate 25 is fixedly connected to the side wall and the circular end plate 22 of the tunnel booster chamber 15 and does not rotate with the rotating shaft 23. In order to prevent pressure release, the arc length of two adjacent arc-shaped plates 25 must be greater than the arc length between two adjacent partition plates 24 .

[0049] The air supply duct includes a rigid air duct 2, the front end of which passes through the cave entrance booster chamber 15 and extends through the automatic damper 8. A soft air duct 3 is axially connected to the front end of the rigid air duct 2, which is located in the working space; its rear end passes through the rear wall of the cave entrance booster chamber 15 and is located outdoors. A blower 1 is provided outdoors, and the blower 1 is connected to the rigid air duct 2. A bypass pipe 17 is connected to the side wall of the rigid air duct 2 located outside the cave entrance booster chamber 15, and a bypass valve 18 is installed on the bypass pipe 17. A bypass pipe 17 is connected to the rigid air duct 2 located outside the cave entrance booster chamber 15, and a bypass valve 18 is installed on the bypass pipe 17. The bypass pipe 17 is used to prevent backflow caused by excessive wind pressure in the tunnel.

[0050] Each damper in the right channel and the left channel, as well as the automatic damper 8 include a left sealing plate 28, a right sealing plate 29, an upper sealing plate 30 and a split door plate 31. The left sealing plate 28, the split door plate 31 and the right sealing plate 29 are all vertically arranged and arranged in parallel from left to right; the upper sealing plate 30 is connected to the upper ends of the left sealing plate 28, the split door plate 31 and the right sealing plate 29, and an automatic pressure relief multi-leaf damper 33 is provided on the upper sealing plate 30; a pedestrian door panel 32 is provided at the lower left end of the split door panel 31.

[0051] The present invention also discloses a ventilation method for a pressurized and oxygenated ventilation system for a high-altitude construction tunnel, the ventilation method comprising the following steps:

[0052] Step 1: Set up the cave entrance booster chamber 15, maintain a certain pressure value in the cave entrance booster chamber 15, and the air supply pipe continuously supplies air into the working space to maintain the pressure near the face; when the pressure near the face is too high, the automatic pressure relief multi-leaf wind window 33 on the automatic air door 8 opens to discharge the excess gas into the cave entrance booster chamber 15; when the pressure in the cave entrance booster chamber 15 is too high and the pressure value between the cave entrance booster chamber 15 and the working space is too high, the exhaust pipe 9 discharges the excess gas in the cave entrance booster chamber 15 to the outside;

[0053] Step 2: Wastewater from the face construction process is discharged into the first drainage ditch 19, and then into the first sump 20A. The wastewater in the first sump 20A flows into the second drainage ditch through the first connecting pipe 21A, and then flows into the second sump 20B. The wastewater in the second sump 20B is discharged to the outside through the second connecting pipe, thus completing the non-pressure relief drainage.

[0054] Step 3: The soil during the face construction process is transported to the tunnel entrance booster chamber 15 and transported out by rotating the slag dump 10;

[0055] Step 4: When the vehicle passes through the outer dampers of the left channel and the right channel, the outer damper's automatic pressure relief multi-leaf damper window 33 opens. When the pressure inside and outside the outer damper is balanced, the outer damper is opened, the vehicle passes through the outer damper, the two outer dampers are closed, and the automatic pressure relief multi-leaf damper window 33 of the inner damper is opened. When the pressure inside and outside the inner damper is balanced, the inner damper is opened, the vehicle enters the cave entrance booster chamber 15, and the inner damper is closed;

[0056] When a vehicle passes through the automatic damper 8, the automatic pressure relief multi-leaf windshield 33 of the automatic damper 8 opens to discharge the gas in the working space. When the air pressure before and after the automatic damper 8 is balanced, the automatic damper 8 opens, and when the vehicle passes through the automatic damper 8, the automatic damper 8 closes.

[0057] In the present invention, a tunnel portal booster chamber and automatic dampers are provided in the tunnel to maintain the face air pressure close to the design requirements. There is no need to set up a separate oxygen supply system, and the oxygen partial pressure is increased by boosting to meet the oxygen supply. The gradient pressure distribution inside the tunnel is achieved by relying on the exhaust duct and the automatic dampers in the tunnel to avoid damage to the dampers due to excessive pressure difference. In addition, the effect of reducing the exhaust wind speed is also achieved.

Claims

1. A pressurized and oxygenated ventilation system for high-altitude construction tunnels, characterized in that: It comprises a cave entrance pressurizing chamber (15), an automatic damper (8), a hard air duct (2) and an exhaust duct (9), wherein: The entrance booster chamber (15) is arranged at the entrance of the tunnel, and is a closed space, the front end of which is connected to the tunnel and communicates with the inside of the tunnel; its left-right width is greater than the left-right span of the tunnel; the entrance booster chamber (15) maintains a set pressure; The right side of the boost chamber (15) near the rear end extends to the right to form a right channel; the left side extends to the left to form a left channel; two dampers are arranged in the right channel and the left channel at intervals on the left and right, and in each channel, the two dampers cannot be opened or closed at the same time; The automatic damper (8) is arranged in the tunnel hole, and forms a closed working space with the front tunnel face; the space at the rear end is connected to the booster chamber (15); an automatic pressure relief multi-leaf wind window (33) is arranged on the upper part of the automatic damper (8); the working space is connected to an air supply pipe, and the air supply pipe continuously supplies air to the working space, so that the working space is maintained at a high pressure; when the pressure value is greater than the set pressure, the gas in the working space is discharged into the booster chamber (15) through the wind window (33); The exhaust duct (9) has a front section located in the hole booster chamber (15), and a rear section passing through the rear side wall of the hole booster chamber (15) and located outdoors; the exhaust duct (9) is used to discharge excess gas in the booster chamber (15) to the outdoors; and to maintain the pressure difference between the booster chamber (15) and the working space within a set range.

2. A pressurized and oxygenated ventilation system for high altitude construction tunnels as claimed in claim 1, characterized in that: A first drainage ditch (19) is excavated on the left or right side of the tunnel, and the direction of the first drainage ditch (19) is consistent with the direction of the tunnel; a first water collection pit (20A) is excavated in the direction of the first drainage ditch (19) in the working space and close to the automatic damper (8), and the depth of the first water collection pit (20A) is lower than the lower end of the automatic damper (8); A second drainage ditch is excavated in the cave entrance booster chamber (15) and located on the side where the first drainage ditch (19) is located, and the front end of the second drainage ditch is connected to the bottom of the first sump (20A) through a first connecting pipe (21A), and the first connecting pipe (21A) includes a vertical section connected to the second drainage ditch and a horizontal section connected to the first sump (20A), and the horizontal section is located below the ground; The rear end of the second drainage ditch discharges sewage to the outside of the cave entrance booster chamber (15) through a second connecting pipe.

3. A pressurized and oxygenated ventilation system for high altitude construction tunnels as claimed in claim 2, characterized in that: A second sump (20B) is excavated in the cave entrance booster chamber (15) and located at the side wall. The second sump (20B) is used to receive sewage discharged from the second drainage ditch. The bottom of the second sump (20B) is connected to the horizontal section of the second connecting pipe, and the horizontal section is connected to a vertical section. The horizontal section is located in the soil below the side wall of one side of the cave entrance booster chamber (15) and spans the side wall. The vertical section is vertically upward, with its lower end connected to the outlet of the horizontal section, and its upper end is used to connect to the sewage receiving device.

4. A pressurized and oxygenated ventilation system for high altitude construction tunnels as claimed in claim 3, characterized in that: The height of the first connecting pipe (21A) is greater than the height of the water column of the pressure difference on both sides of the automatic damper (8) in the tunnel, and the height of the second connecting pipe (21B) is greater than the height of the water column of the pressure difference on both sides of the side wall of the cave entrance booster chamber (15).

5. A pressurized and oxygenated ventilation system for high altitude construction tunnels as claimed in claim 4, characterized in that: A rotating slag discharge bucket (10) is arranged on the side wall at the rear end of the tunnel entrance booster chamber (15), and the rotating slag discharge bucket (10) comprises a cylindrical shell, which is embedded in the side wall and is formed by a plurality of arc-shaped plates (25) connected end to end, and both ends of the cylindrical shell are closed by circular end plates (22); an opening is opened on the cylindrical shell; a rotating shaft (23) is coaxially passed through the central axis of the cylindrical shell, and both ends of the rotating shaft (23) pass through the circular end plates (22); a plurality of partition plates (24) are arranged on the rotating shaft (23) at intervals around the rotating shaft (23), the length direction of each partition plate (24) is consistent with the direction of the rotating shaft (23), and the width direction extends to the inner wall of the cylindrical shell, and an independent space is formed between two circumferentially adjacent partition plates (24) for receiving slag transported out of the tunnel, which is driven by the rotating shaft (23) to be discharged to the outside of the tunnel entrance booster chamber (15).

6. A pressurized and oxygenated ventilation system for high altitude construction tunnels as claimed in claim 5, characterized in that: The air supply duct comprises a hard air duct (2), the front end of the hard air duct (2) passes through the hole booster chamber (15) and extends through the automatic damper (8), and the front end of the hard air duct (2) is axially connected to the soft air duct (3) and is located in the working space; the rear end thereof passes through the rear side wall of the hole booster chamber (15) and is located outdoors.

7. A pressurized and oxygenated ventilation system for high altitude construction tunnels as claimed in claim 6, characterized in that: Each damper in the right channel and the left channel, as well as the automatic damper (8) include a left sealing plate (28), a right sealing plate (29), an upper sealing plate (30) and a split door plate (31); the left sealing plate (28), the split door plate (31) and the right sealing plate (29) are vertically arranged and arranged in parallel from left to right; the upper sealing plate (30) is connected to the upper ends of the left sealing plate (28), the split door plate (31) and the right sealing plate (29); an automatic pressure relief multi-leaf damper (33) is provided on the upper sealing plate (30); and a pedestrian door plate (32) is provided at the lower left end of the split door plate (31).

8. A ventilation method for a pressurized and oxygenated ventilation system for a high-altitude construction tunnel according to any one of claims 1 to 7, characterized in that: The ventilation methods include the following: Step 1, setting a cave entrance booster chamber (15), maintaining a certain pressure value in the cave entrance booster chamber (15), and the air supply pipe continuously supplies air into the working space to maintain the pressure near the tunnel face; when the pressure near the tunnel face is too high, the automatic pressure relief multi-leaf wind window (33) on the automatic air door (8) opens to discharge the excess gas into the cave entrance booster chamber (15); when the pressure in the cave entrance booster chamber (15) is too high and the pressure value between the cave entrance booster chamber (15) and the working space is too high, the exhaust pipe (9) discharges the excess gas in the cave entrance booster chamber (15) to the outside; Step 2: wastewater generated during the face construction process is discharged into the first drainage ditch (19), and then flows into the first sump (20A) in sequence; the wastewater in the first sump (20A) flows into the second drainage ditch through the first connecting pipe (21A), and then flows into the second sump (20B); the wastewater in the second sump (20B) is discharged outdoors through the second connecting pipe, thereby completing the non-pressure relief drainage; Step 3: The soil during the face construction process is transported to the tunnel entrance booster chamber (15) and transported out by rotating the slag dump bucket (10); Step 4: When the vehicle passes through the outer dampers of the left channel and the right channel, the outer damper's automatic pressure relief multi-leaf damper window (33) opens. When the pressure inside and outside the outer damper is balanced, the outer damper is opened, the vehicle passes through the outer damper, the two outer dampers are closed, and the automatic pressure relief multi-leaf damper window (33) of the inner damper is opened. When the pressure inside and outside the inner damper is balanced, the inner damper is opened, the vehicle enters the cave entrance booster chamber (15), and the inner damper is closed; When a vehicle passes through the automatic damper (8), the automatic pressure relief multi-leaf damper (33) of the automatic damper (8) opens to discharge the gas in the working space; when the air pressure before and after the automatic damper (8) is balanced, the automatic damper (8) opens and the vehicle passes through the automatic damper (8).

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