A shield machine pressure-controlled cutter-changing operation pressurization system and pressurization control method

Abstract

The present invention discloses a pressurizing system and pressurizing control method for shield machine tool change operation under pressure. The shield machine tool change under pressure adopts non-saturated high-pressure operation. The pressurizing system includes a mixed gas distribution system, a man cabin, and an oronasal mask respirator. The mixed gas distribution system is used to configure a helium-nitrogen-oxygen ternary gas mixture. The man cabin is connected to the mud and water tank, and the man cabin is connected to the shield machine's own pressurizing device. The pressurizing device adjusts the cabin pressure by filling the man cabin with compressed air. The mixed gas distribution system is connected to the oronasal mask respirator located in the man cabin through a high-pressure hose. After entering the man cabin, the operator wears the oronasal mask respirator and then enters the mud and water tank from the man cabin to perform the tool change operation. After completing the tool change, the operator returns to the man cabin. The present invention eliminates the traditional living cabin and shuttle cabin. The operator directly enters the man cabin and breathes the helium-nitrogen-oxygen ternary gas mixture by wearing an oronasal mask respirator, quickly adapting to the high-pressure working environment and safely entering the mud and water tank to perform the tool change operation.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, and in particular to a shield pressure-generating cutter-changing operation pressurizing system and an intelligent income and expenditure die method. Background Art

[0002] Currently, the commonly used methods for shield tunneling under pressure include air pressure and helium-oxygen saturation pressure. Specifically, in shallower operating environments, high-pressure operations are usually used, with trained high-pressure workers working in a decompression chamber. In medium-depth environments, conventional air diving is used, with specially trained air divers performing the operation, but this significantly limits the operating time. In deeper operating environments, helium-oxygen saturation diving is used, with specially trained mixed gas divers and saturation divers performing the operation. This requires saturation diving chambers, transfer chambers, and corresponding diving equipment, and the high demand for helium leads to high economic costs. For example, CN112943270A discloses a construction method for pressurized cutter replacement in a large-diameter shield machine under ultra-high water pressure. This method uses the helium-oxygen saturation pressure method, which requires a living chamber and a shuttle chamber. Operators need to gradually pressurize the living chamber to adapt to the high-pressure environment, and then transfer to the soil chamber via the shuttle chamber to perform the cutter replacement operation. Helium-oxygen mixed gas is also required to replace the air in the shield machine's personnel and mud chambers.

[0003] With the increasing pressure requirements for shield cutter changing operations, as well as the increasing depth of tunnel construction and increasingly complex strata, traditional operating methods have gradually exposed numerous shortcomings. Conventional compressed air pressurized chamber opening operations require repeated pressurization and decompression, significantly reducing working time in the mud and water chamber and significantly extending decompression time in the manhole, significantly impacting operator efficiency within the chamber. Saturated pressurized operations also have the following drawbacks: First, heavy diving gear restricts operator freedom of movement, resulting in overall low work efficiency. Second, while helium-oxygen saturation diving in deep working environments can meet high-pressure operation requirements, the high helium consumption and complex equipment significantly increase both economic costs and operational difficulty. Therefore, there is an urgent need to develop a pressurized cutter changing operation system and control method that can adapt to the increasing operating pressure requirements while simplifying the operation process, improving work efficiency, and reducing costs, so as to better meet the safety and efficiency requirements of continuous shield tunneling in deep buried tunnels. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention proposes a pressurization system and pressurization control method for shield machine tool change operations under pressure, eliminating the traditional living cabin and shuttle cabin structure. Operators can directly enter the cabin and breathe a helium-nitrogen-oxygen ternary gas by wearing an oral and nasal mask respirator. Combined with an optimized staged pressurization control method, they can quickly adapt to the high-pressure working environment and safely enter the mud and water cabin to carry out tool change operations.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A pressurizing system for shield machine tool changing operation under pressure, wherein the shield machine tool changing under pressure adopts non-saturated high-pressure operation, and the pressurizing system includes a mixed gas distribution system, a man cabin, and an oronasal mask respirator. The mixed gas distribution system is used to configure a helium-nitrogen-oxygen ternary gas mixture, and the configured helium-nitrogen-oxygen ternary gas mixture is stored in a mixed gas tank. The man cabin is docked with a mud and water tank, and the man cabin is connected to a pressurizing device provided with a shield machine. The pressurizing device adjusts the cabin pressure by filling the man cabin with compressed air. The mixed gas distribution system is connected to the oronasal mask respirator located in the man cabin through a high-pressure hose, and an intelligent flow regulating valve is provided on the high-pressure hose. The air supply flow of the ternary mixed gas to the oronasal mask respirator is adjusted by the intelligent flow regulating valve. The operator wears the oronasal mask respirator after entering the man cabin, and then enters the mud and water tank from the man cabin to perform the tool changing operation. After completing the tool changing, the operator returns to the man cabin.

[0007] Preferably, the man cabin includes a cabin door, and workers enter the man cabin directly through the cabin door from the shield machine without setting up a living cabin and a shuttle cabin. A sealed door is provided between the man cabin and the mud and water cabin.

[0008] Preferably, the man cabin includes an air outlet valve, which is opened after pressurization is completed to establish an air inlet and outlet balance in the man cabin, and the air pressure is stabilized at a set pressure.

[0009] Preferably, the operator always wears the oronasal mask respirator to breathe a ternary mixture of helium, nitrogen and oxygen when performing tool replacement and mud cake removal operations in the mud and water tank, and monitors the concentration of nitrogen in the ternary mixture during the operation.

[0010] Preferably, an intercom and a handwriting board are provided in the cabin, and the intercom communicates with the control room.

[0011] Preferably, an alarm device is provided in the man cabin, and the alarm device is used to identify the working status of the operator and upload the working status information to the control room.

[0012] On the other hand, the present invention also discloses a pressurization control method based on the above-mentioned shield pressure-driven cutter-changing operation pressurization system, comprising the following steps:

[0013] S1: The helium-nitrogen-oxygen ternary gas mixture configured in the gas mixture distribution system is introduced into the cabin through a high-pressure hose;

[0014] S2: After the operator enters the cabin, the shield machine's built-in pressurizing device is activated to fill the cabin with compressed air at a rate of 1.5 bar / min;

[0015] At S3, when the cabin pressure reaches 2.4 bar, the operator begins to wear a mouth-nose respirator and breathe the ternary mixed gas;

[0016] S4: When the pressure reaches 3.0 bar, pause the pressure increase and confirm that the oronasal mask respirator is working properly through voice or handwritten text;

[0017] S5: After confirming that there are no abnormalities, continue to increase the pressure to the operating pressure at a rate of 1.5 bar / min;

[0018] S6: After reaching the preset operating pressure, the operator wears a mouth-nose respirator and enters the mud and water tank to work.

[0019] Preferably, in step S1, when the pressure of the mixed gas tank of the mixed gas distribution system reaches above 9 Bar, the pressure is adjusted to between 8.5-8.7 Bar through the gas supply pressure regulator. After real-time monitoring by the gas analyzer and the composition and parameters meet the requirements, the gas supply valve is opened and the mixed gas flow detector is used to divide the gas into four paths, and the intelligent flow regulating valve is used to supply gas to the operating personnel according to the set gas supply volume.

[0020] Preferably, the maximum air supply of the oronasal mask respirator is 210L / min, and the operator can adjust the air supply according to his or her actual situation.

[0021] Preferably, the preset operating pressure is 5.7 bar, the overall pressurization time is 5 minutes, the ternary gas mixture is set to have a nitrogen partial pressure of 2.9 ATA, an oxygen partial pressure of 1.6 ATA, and a helium partial pressure of 2.2 ATA, and the operating residence time is 70 minutes.

[0022] The beneficial effects of the present invention are as follows: The pressurization system and pressurization control method for shield tunneling cutter changing operations provided by the present invention adopt a non-saturated high-pressure operation method, which can complete pressurization preparation in a relatively short time, avoiding the cumbersome process of long-term pressurization and decompression in traditional saturation diving operations. By eliminating the living cabin and shuttle cabin, operators can directly enter the human cabin for pressurization and wear a mouth-nasal mask respirator to inhale a helium-nitrogen-oxygen ternary gas mixture, which simplifies the operation process, shortens the operation cycle, makes breathing smoother, and significantly improves construction efficiency. The pressurization system adopts a staged and controllable pressurization control method, allowing operators to quickly adapt to the high-pressure environment and enter the mud and water tank to carry out operations, thereby improving operation efficiency and adaptability. At the same time, through the precise ratio of the helium-nitrogen-oxygen ternary gas mixture, the nitrogen partial pressure is strictly controlled below 4.0ATA, avoiding the risk of nitrogen narcosis in a high-pressure environment. This not only improves the safety of the operation, but also enables the system to adapt to higher operating pressure environments, expanding the pressure limit of shield tunneling operations. The pressurization system uses a ternary gas mixture instead of the traditional helium-oxygen mixture, and only needs to supply air to the oronasal mask respirator, which not only ensures operational safety but also significantly reduces helium consumption, offering better economic efficiency. The present invention has a compact structure and is easy to operate, making it suitable for a variety of working conditions, such as deep burial, complex strata, and high water and soil pressure. It effectively solves the technical problem of being unable to use air pressure to open the warehouse under high operating pressure conditions. In addition, the cabin is equipped with an intercom, a writing board, and an alarm device, enabling real-time communication with the control room and operational status monitoring, further enhancing the system's controllability and emergency response capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an overall schematic diagram of a pressurizing system for a shield machine tool change operation under pressure according to an embodiment of the present invention;

[0024] Figure 2 It is a flow chart of a pressurization control method of a pressurization system for a shield machine with pressure cutter changing operation according to an embodiment of the present invention.

[0025] Figure numerals: 1-mixed gas distribution system; 2-personnel cabin; 3-oral and nasal mask respirator; 4-mixed gas tank; 5-pressurization device; 6-high-pressure hose; 7-intelligent flow regulating valve; 8-cabin door; 9-sealed door; 10-exhaust valve; 11-intercom; 12-control room; 13-alarm device. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the present invention.

[0027] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0028] See also Figure 1 This embodiment provides a pressurization system for shield machine tool change operations under pressure. Shield machine tool change under pressure uses non-saturated high-pressure operations. Saturated high-pressure operations refer to operations in an environment with a pressure higher than atmospheric pressure, with continuous exposure for 24 hours or more, resulting in the saturation of the body's tissues with inert gas. Non-saturated high-pressure operations refer to operations in a high-pressure environment without the operator entering a saturated diving state, thereby reducing pressurization and decompression time and improving work efficiency. The pressurization system includes a mixed gas distribution system 1, a man cabin 2, and an oronasal mask respirator 3. The mixed gas distribution system 1 is used to configure a helium-nitrogen-oxygen ternary gas mixture. The helium-nitrogen-oxygen ternary gas mixture has the characteristics of low nitrogen and constant oxygen, which helps control the nitrogen partial pressure and avoid nitrogen narcosis. The nitrogen partial pressure is higher than the helium partial pressure. The configured helium-nitrogen-oxygen ternary gas mixture is stored in a mixed gas tank 4, which is a high-pressure gas storage container used to ensure continuous and stable gas supply. The man cabin 2 is connected to the mud and water tank. The man cabin 2 serves as the pressurized space for operators before entering the operation and is directly connected to the mud and water tank at the tunneling end of the shield machine. Furthermore, the manhole 2 is connected to the shield machine's built-in pressurization device 5, which regulates the cabin pressure by filling the manhole 2 with compressed air. This pressurization process is essential for personnel entering the high-pressure working environment, ultimately reaching the preset working pressure. The mixed gas distribution system 1 is connected to the oronasal respirator 3 located within the manhole 2 via a high-pressure hose 6. The high-pressure hose 6 must be high-pressure and corrosion-resistant to ensure safe gas delivery. An intelligent flow control valve 7 is installed on the high-pressure hose 6 to regulate the flow rate of the ternary mixed gas supplied to the oronasal respirator 3. Specifically, the intelligent flow control valve 7 automatically adjusts the mixed gas supply based on the operator's breathing state, ensuring a stable air supply and smooth breathing. After entering the manhole 2, the operator dons the oronasal respirator 3, pressurizing it to the preset working pressure. They then proceed from the manhole 2 to the mud and water tank to perform a tool change operation, working in the stable high-pressure environment within the mud and water tank. After completing the tool change, the operator returns to the manhole 2 to prepare for subsequent decompression or evacuation.

[0029] Furthermore, the man cabin 2 includes a door 8, through which workers enter the man cabin 2 directly from the shield machine. Once the door 8 is opened, workers can enter the pressurized cabin directly without passing through the living cabin and shuttle cabin. This effectively simplifies the traditional multi-cabin serial operation process, reduces the pressure conversion between pressurization and decompression, and eliminates the need for living cabins and shuttle cabins. This structure not only saves equipment layout space but also significantly improves the efficiency of tool change preparation. A sealed door 9 is provided between the man cabin 2 and the mud and water cabin. This sealed door 9 is used to ensure airtightness between the two cabins. After pressurization is completed, it can maintain the pressure differential between the man cabin 2 and the mud and water cabin, preventing compressed gas leakage or mud and water backflow. The man cabin 2 includes an air outlet valve 10. After pressurization is completed, the air outlet valve 10 is opened to regulate the release of excess gas in the man cabin 2, so that the cabin pressure is consistent with the preset target value, establish air inlet and outlet balance in the man cabin 2, and stabilize the air pressure at the set pressure, ensuring that workers enter the mud and water cabin in a stable high-pressure environment and maintaining air pressure consistency during operation.

[0030] In this embodiment, the operator always wears an oronasal mask respirator 3 to breathe a ternary mixture of helium, nitrogen and oxygen when performing tool replacement and mud cake removal operations in the mud and water tank. Nitrogen is used as an auxiliary inert gas, and its concentration needs to be strictly controlled. The concentration of nitrogen in the ternary mixture is monitored during the operation, and the changes in the composition of the mixture are fed back in real time through the gas analysis device to ensure that the nitrogen partial pressure does not exceed the safety threshold, thereby ensuring the breathing safety of the operator during long-term operations in a high-pressure environment.

[0031] In addition, a walkie-talkie 11 and a handwriting tablet are installed in the man cabin 2. The walkie-talkie 11 communicates with the control room 12. The walkie-talkie 11 is used to enable real-time voice communication between the workers in the man cabin 2 and the control room 12, facilitating two-way information transmission during different stages such as pressurization, tool changing, standby, and decompression. The handwriting tablet is used to provide a means of text information transmission in the event of high noise, high pressure, or poor communication, thereby enhancing information redundancy and safety during operation. An alarm device 13 is also installed in the man cabin 2. The alarm device 13 is used to identify the work status of the workers and upload work status information to the control room 12. The alarm device 13 can collect the worker's movement frequency, posture changes, respiratory airflow, or other physiological or behavioral parameters through a sensor module. Combined with preset state judgment logic, it can identify abnormal conditions such as loss of consciousness, abnormal breathing, or prolonged inactivity. Once an abnormality is identified, an alarm signal is sent to the control room 12, facilitating a prompt response by the on-duty personnel, thereby improving safety management and control capabilities during high-pressure operations.

[0032] See also Figure 2 Another embodiment of the present invention further discloses a pressurization control method based on the above-mentioned shield pressure-driven cutter-changing operation pressurization system, comprising the following steps:

[0033] S1, the helium-nitrogen-oxygen ternary gas mixture configured in the gas mixture distribution system 1 is introduced into the human cabin 2 through the high-pressure hose 6.

[0034] In this step, the mixed gas distribution system 1 precisely controls the proportion of helium, nitrogen and oxygen and mixes them. The resulting ternary mixed gas is stored in the mixed gas tank 4 and introduced into the human cabin 2 through the high-pressure hose 6 to ensure that the gas supply composition is stable and the pressure is adapted. The high-pressure hose 6 has a reliable connection and good pressure resistance, which can ensure that the gas does not leak or deteriorate during the transmission process.

[0035] S2: After the operator enters the cabin 2, he starts the shield machine's built-in pressurizing device 5 to fill the cabin with compressed air at a rate of 1.5 bar / min.

[0036] In this step, the pressurizing device 5 gradually increases the ambient air pressure in the cabin 2 through the cabin sealing system. The pressurizing rate of 1.5 bar / min takes into account both operating efficiency and personnel adaptability to ensure a smooth and safe pressurization process.

[0037] At step 3, when the cabin pressure reaches 2.4 bar, the operator begins breathing the ternary gas mixture through an oronasal mask respirator 3. To prevent nitrogen narcosis, which can occur due to rapid dissolution of nitrogen in the body, the operator wears an oronasal mask respirator 3 and inhales the prepared helium, nitrogen, and oxygen mixture, gradually acclimating the body to the breathing pattern of the mixed gas and laying the foundation for subsequent operations in higher-pressure environments.

[0038] S4: When pressurization reaches 3.0 bar, pause and confirm the normal operation of the oronasal mask respirator 3 via voice or handwritten text. This step verifies the normal operation of the mixed gas channel, the intelligent flow control valve 7, the respirator's tightness, and the subjective inhalation experience of the personnel. Voice is transmitted via the intercom 11, and handwritten text can be completed using the handwriting board installed in the cabin 2 to ensure that the operating conditions of all systems during the pressurization process are controllable.

[0039] S5: After confirming that there are no abnormalities, the system continues to pressurize the cabin to the operating pressure at a rate of 1.5 bar / min. At this point, the operator is breathing a stable mixed gas. The system continues to fill the cabin 2 with compressed air and gradually increases it to the preset operating pressure, preparing the air pressure for entering the mud and water tank.

[0040] At step S6, after reaching the preset operating pressure, the operator dons an oronasal respirator 3 and enters the mud and water tank to work. The oronasal respirator 3 remains connected to the mixed gas distribution system 1, ensuring stable breathing and gas composition that meets safety requirements throughout the operation. After completing tasks such as tool replacement and mud cake removal, the operator can return to the manhole 2 to prepare for decompression and exit. This entire pressurization control method balances safety, adaptability, and operational efficiency in high-pressure environments.

[0041] In a specific embodiment, in step S1, when the pressure of the mixed gas tank 4 of the mixed gas distribution system 1 reaches 9 Bar or more, the pressure is adjusted to between 8.5 and 8.7 Bar by the gas supply pressure regulator. The mixed gas tank 4 serves as a storage device for the mixed gas, and its internal gas pressure needs to reach a certain value to meet the subsequent stable gas supply demand. The gas supply pressure regulator is used to adjust the high-pressure gas in the tank to a working pressure range suitable for delivery to the oral and nasal mask respirator 3, ensuring gas supply safety and flow stability. After real-time monitoring by the gas analyzer, when the composition and parameters meet the requirements, the gas supply valve is opened and divided into four paths through the mixed gas flow detector. The gas analyzer detects the consistency of the volume fraction of the helium, nitrogen, and oxygen ternary mixed gas with the set value in real time. The gas supply valve can be activated only after confirming that there is no deviation. The mixed gas flow detector divides the mixed gas into four parts, which is suitable for multiple operators or multi-point gas supply scenarios. The intelligent flow control valve 7 supplies gas to the operators according to the set gas supply volume. The intelligent flow control valve 7 dynamically adjusts the gas flow rate according to the system settings and operator feedback to achieve precise gas supply control.

[0042] Specifically, the maximum air supply volume of the oronasal mask respirator 3 is 210L / min. The operator can fine-tune the air supply volume according to his or her actual situation. As a closed breathing device, the oronasal mask respirator 3 provides a set flow of mixed gas while maintaining air tightness. 190L / min is the maximum theoretical air supply flow required for this device to adapt to working conditions. The air supply volume can be fine-tuned by the operator through the regulating valve according to physical factors such as inhalation resistance and respiratory frequency to maintain a relaxed and comfortable inhalation state, avoid discomfort such as holding breath and chest tightness, and ensure working comfort.

[0043] In this embodiment, the preset operating pressure is 5.7 bar, and the overall pressurization time is 5 minutes. The preset operating pressure is the minimum pressure condition required for operators to enter the mud and water tank to overcome the water and soil pressure and ensure the safety of the operation. 5 minutes is the time required for pressurization from normal pressure to the operating pressure. The operation preparation time is shortened as much as possible within the safe range. The ternary gas mixture sets the nitrogen partial pressure to 2.9ATA, the oxygen partial pressure to 1.6ATA, and the helium partial pressure to 2.2ATA. The partial pressures of the three gases are precisely controlled. The nitrogen partial pressure is strictly controlled below 4.0ATA to effectively avoid the risk of high-pressure nitrogen anesthesia. The oxygen partial pressure is maintained within the safe range of human metabolism, and the helium partial pressure is used to reduce the density of the mixture and breathing resistance. The operation residence time is 70 minutes, that is, the continuous operation time of the operator in the mud and water tank to maintain a high-pressure mixed gas breathing environment. This time is set in combination with the amount of tool changing tasks and the pressure endurance of the personnel to ensure the completion of the task while avoiding overtime exposure.

[0044] In this embodiment, the ratio of the helium-nitrogen-oxygen ternary gas mixture during the pressurization process not only considers respiratory safety and nitrogen narcosis risk control during the operation, but also comprehensively considers decompression efficiency after the operation. Specifically, nitrogen is used as the inert gas basis for determining the most unfavorable water depth in the gas mixture. That is, the nitrogen partial pressure is used as the controlling factor for tissue gas dissolution and release in the decompression scheme. Compared with traditional decompression models that use helium as the basis for the most unfavorable water depth, this significantly shortens decompression time. Due to the faster diffusion rate of helium and its more sensitive tissue saturation and desaturation processes, decompression design based on helium requires longer step-by-step decompression to prevent bubble precipitation and decompression sickness. However, by rationally controlling the nitrogen partial pressure (for example, limiting it to below 4.0 ATA), the present invention not only effectively avoids nitrogen narcosis, but also reduces the intensity of control over the release of the most unfavorable tissue gas during decompression path planning, thereby shortening decompression time and improving overall operation efficiency and post-operation personnel recovery.

[0045] In the present invention, workers breathe a helium-nitrogen-oxygen ternary gas mixture while wearing an oronasal mask respirator 3 in the human cabin 2. The partial pressure of the gases in the body generated by the breathing process increases synchronously with the gradual increase in the ambient pressure of the human cabin 2, thereby achieving consistency between the "internal pressurization" process in the worker's body and the "external pressurization" process in the human cabin 2. As the human cabin 2 is continuously pressurized at a set rate by the pressurizing device 5, the ambient pressure in the cabin gradually rises. The worker continues to inhale the high-pressure ternary gas mixture, and gases are continuously exchanged between the alveoli and the blood, causing the dissolved partial pressures of gases such as nitrogen, helium, and oxygen in the body to rise synchronously with the cabin pressure. Ultimately, the worker's body pressure and the cabin pressure are balanced within a specified time, thereby avoiding pressure injuries caused by an imbalance in the internal and external pressure differences and ensuring the safety and physiological stability of the worker's high-pressure adaptation process.

[0046] In summary, the present invention discloses a pressurization system and pressurization control method for shield tunneling tool change operations under pressure. This pressurization system utilizes a non-saturated high-pressure operation method, eliminating the traditional living cabin and shuttle cabin structures. It integrates a mixed gas distribution system 1, a human cabin 2, and an oronasal mask respirator 3. This system achieves precise proportioning and safe delivery of a helium-nitrogen-oxygen ternary gas mixture, coordinated regulation of the internal and external pressures of the human cabin 2, efficient linkage between the operator and the control room 12, and real-time monitoring of the operating status. The pressurization control method, based on the principle of phased and synchronous pressurization, establishes a scientific and reasonable pressure rhythm and breathing gas management scheme, ensuring that the gas partial pressure in the operator's body rises synchronously with the ambient pressure in the human cabin 2, thereby establishing a high-pressure adaptation mechanism that coordinates internal and external pressurization. The system and method of the present invention effectively address the technical difficulties of low operating efficiency, long decompression cycles, high helium consumption, bulky equipment, and complex operation in conventional saturation diving pressurized operations. Compared with traditional saturation diving pressurized operations, the present invention significantly simplifies the operating process, shortens operation preparation time, improves operation efficiency, and effectively reduces operating costs and the physiological burden on personnel, while ensuring operational safety. The present invention provides a practical, efficient and safe technical solution for high-pressure cutter changing operations in shield tunneling. It is particularly suitable for cutter changing operations under high water and soil pressure, complex strata and other working conditions in deep-buried and long-distance shield tunnels. It has important engineering application value and industry promotion significance in ensuring the safety of high-pressure operations and improving engineering operation efficiency.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that it is still possible to modify the technical solutions described in the above embodiments, or to make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A shield machine pressure-changing tool change operation pressurization system, characterized in that: The shield machine adopts non-saturated high-pressure operation for the pressurized tool change. The pressurization system includes a mixed gas distribution system (1), a human cabin (2), and an oronasal mask respirator (3). The mixed gas distribution system (1) is used to configure a helium-nitrogen-oxygen ternary mixed gas. The configured helium-nitrogen-oxygen ternary mixed gas is stored in a mixed gas tank (4). The human cabin (2) is docked with the mud and water cabin. The human cabin (2) is connected to a pressurization device (5) provided with the shield machine. The pressurization device (5) adjusts the cabin pressure by filling the human cabin (2) with compressed air. The mixed gas distribution system (1) is connected to the oronasal mask respirator (3) located in the human cabin (2) through a high-pressure hose (6). The high-pressure hose (6) is provided with an intelligent flow regulating valve (7). The intelligent flow regulating valve (7) is used to adjust the ternary mixed gas of the oronasal mask respirator (3). The air supply flow of the gas is reduced. The pressurization system eliminates the living cabin and the shuttle cabin. The operator directly enters the human cabin (2) for pressurization. After entering the human cabin (2), the operator wears a mouth-nose mask respirator (3), and then enters the mud and water cabin from the human cabin (2) to perform a tool change operation. After completing the tool change, the operator returns to the human cabin (2); after entering the human cabin, the operator starts the pressurization device (5) to fill the cabin with compressed air at a rate of 1.5 bar / min; when the cabin pressure reaches 2.4 bar, the operator starts wearing the mouth-nose mask respirator (3) to breathe the ternary mixed gas; when the pressure is continuously increased to 3.0 bar, the pressurization is suspended and the mouth-nose mask respirator (3) is confirmed to be working normally through voice or handwritten text; after confirming that there is no abnormality, the pressurization rate is continued to increase to the operating pressure at a rate of 1.5 bar / min.

2. The shield machine pressure-assisted cutter changing operation pressurization system according to claim 1 is characterized in that: The man cabin (2) includes a cabin door (8), and workers enter the man cabin (2) directly through the cabin door (8) from the shield machine without providing a living cabin and a shuttle cabin. A sealed door (9) is provided between the man cabin (2) and the mud and water cabin.

3. The shield machine tool changing operation pressurization system according to claim 1 is characterized in that: The human cabin (2) includes an air outlet valve (10). After pressurization is completed, the air outlet valve (10) is opened to establish an air inlet and outlet balance of the human cabin (2), and the air pressure is stabilized at a set pressure.

4. The shield machine tool changing operation pressurization system according to claim 1 is characterized in that: When the operator performs the operations of tool replacement and mud cake removal in the mud and water tank, he always wears the oronasal mask respirator (3) to breathe the helium, nitrogen and oxygen ternary gas mixture, and monitors the concentration of nitrogen in the ternary gas mixture during the operation.

5. The shield machine pressure-assisted cutter changing operation pressurization system according to claim 1 is characterized in that: An intercom (11) and a handwriting board are provided in the human cabin (2), and the intercom (11) communicates with the control room (12).

6. The shield machine pressure-assisted cutter-changing operation pressurization system according to claim 4 is characterized in that: An alarm device (13) is provided in the man cabin (2), and the alarm device (13) is used to identify the working status of the operator and upload the working status information to the control room (12).

7. A pressurization control method for a shield machine tool change operation pressurization system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, the helium-nitrogen-oxygen ternary gas mixture configured in the gas mixture distribution system (1) is connected to the human cabin (2) through a high-pressure hose (6); S2, after the operator enters the cabin (2), the shield machine's built-in pressurizing device (5) is activated to fill the cabin with compressed air at a rate of 1.5 bar / min; S3, when the cabin pressure reaches 2.4 bar, the operator starts wearing a mouth-nose respirator (3) to breathe the ternary mixed gas; S4, when the pressure is continuously increased to 3.0 bar, the pressure is stopped and the oronasal mask respirator (3) is confirmed to be working properly by voice or handwriting; S5: After confirming that there are no abnormalities, continue to increase the pressure to the operating pressure at a rate of 1.5 bar / min; S6, after reaching the preset operating pressure, the operator wears a mouth-nose respirator (3) and enters the mud and water tank to operate.

8. The pressurization control method for a pressurization system for a shield machine tool changing operation under pressure according to claim 7, characterized in that: In step S1, when the pressure of the mixed gas tank (4) of the mixed gas distribution system (1) reaches above 9 Bar, the pressure is adjusted to between 8.5 and 8.7 Bar by the gas supply pressure regulator. After the gas analyzer monitors the composition and parameters in real time and the gas meets the requirements, the gas supply valve is opened and the mixed gas flow detector is used to divide the gas into four paths. The gas is then supplied to the operator according to the set gas supply volume through the intelligent flow control valve (7).

9. The pressurization control method for a pressurization system of a shield machine tool changing operation under pressure according to claim 8, characterized in that: The maximum air supply of the oronasal mask respirator is 210L / min, and the operator can fine-tune the air supply according to their actual situation.

10. The pressurization control method for a pressurization system of a shield machine tool changing operation under pressure according to claim 9, characterized in that: The preset operating pressure is 5.7 bar, the overall pressurization time is 5 minutes, the ternary gas mixture is set to have a nitrogen partial pressure of 2.9 ATA, an oxygen partial pressure of 1.6 ATA, and a helium partial pressure of 2.2 ATA, and the operating residence time is 70 minutes.

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