A life support system for mixed gas shield tunneling under pressure

Abstract

The present invention discloses a mixed gas shield pressure operation life support system, which is suitable for non-saturated shield high-pressure operation, and includes an air compressor module, a compressed air storage tank, a gas source bottle group, a mixed gas distribution module, a man cabin and a micro-pressure oxygen chamber; the air compressor module stores compressed and purified air in the compressed air storage tank; the gas source bottle group includes a helium cylinder group and an oxygen cylinder group connected in parallel; the mixed gas distribution module includes an automatic distribution component, a manual distribution component and a mixed gas storage tank, which mix and proportion compressed air, oxygen and helium; the man cabin is used for pressurization and decompression of workers before and after pressure work, and an oral and nasal mask respirator and a film hood are provided in the cabin; the micro-pressure oxygen chamber is used to receive workers for oxygen therapy after the decompression of the man cabin is completed. The present invention eliminates the living cabin and the shuttle cabin, and realizes efficient linkage between each gas source module and the man cabin through modular integration, thereby improving work efficiency and safety in a high-pressure pressure operation environment.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, in particular to a mixed gas shield pressure operation life support system. Background Art

[0002] At present, shield tunneling pressurized hatch opening operations mainly include two modes: air pressurized operation and helium-oxygen saturation operation. For shallow or medium-depth operations, compressed air environment operations are often used. Personnel use oral and nasal mask respirators to perform short-term operations in a high-pressure environment, and rely on traditional decompression chambers to complete the decompression process after the operation. In deeper tunnel environments, in order to meet higher pressure adaptation requirements, helium-oxygen saturation diving operation modes are often used. Such operations require the configuration of multiple functional cabins such as saturation diving cabins, shuttle cabins, and living cabins. Operators need to undergo long-term pressurization, operation, and decompression processes, using helium-oxygen mixed gas breathing to control the risks of nitrogen narcosis and oxygen poisoning, and controlling the desaturation rate of inert gas through a staged decompression strategy. Because multiple cabins are involved, the number, configuration, and gas regulation of mixed gas cylinders, oxygen cylinders, and helium cylinders are also relatively complex, resulting in cumbersome operating procedures and greater management difficulties.

[0003] However, existing helium-oxygen saturation pressurized operation systems suffer from numerous shortcomings. First, such systems are complex in structure, require numerous chambers, occupy a large amount of space, and have low system integration. Their operation relies on a large number of equipment and occupies limited space behind the shield tunnel. Second, helium, as a rare gas, consumes a large amount of gas, resulting in high operating costs. This is particularly true during long-term, high-pressure operations, where the economic burden is even heavier. Furthermore, helium-oxygen saturation operations are generally only suitable for long-term, high-depth, continuous operations and are not suitable for operations requiring short cycles and frequent tool changes. Their overall efficiency is low, their response is slow, and they cannot meet the requirements of modern tunnel construction at a rapid pace. Furthermore, if workers improperly control the decompression operation during saturation operations, they are highly susceptible to serious physiological reactions such as decompression sickness, posing a high safety risk and relying heavily on operational specifications and a stable working environment. Therefore, existing life support systems urgently need to be optimized and innovated in multiple aspects, including structural design, gas distribution, safety control, and operational efficiency, to adapt to the deep-buried, high-pressure, and fast-paced shield tunneling pressurized tool-changing environment. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention proposes a mixed gas shield pressurized operation life support system, which eliminates the traditional living cabin and shuttle cabin structure, and realizes efficient linkage between each gas source module and the human cabin through modular integration, thereby improving work efficiency and safety in high-pressure pressurized operation environment.

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

[0006] A life support system for mixed gas shield operation under pressure, which adopts a modular combination design and is suitable for non-saturated high-pressure operation, including an air compressor module, a compressed air storage tank, a gas source bottle group, a mixed gas distribution module, a human cabin and a micro-pressure oxygen cabin; the air compressor module stores compressed and purified air in the compressed air storage tank, and the compressed air storage tank is connected to the mixed gas distribution module through a high-pressure pipeline to provide compressed air; the gas source bottle group includes a helium bottle group and an oxygen bottle group connected in parallel, which are respectively connected to the mixed gas distribution module through high-pressure pipelines to provide oxygen and helium; The mixed gas distribution module includes an automatic gas distribution component, a manual gas distribution component and a mixed gas storage tank. The automatic gas distribution component or the manual gas distribution component mixes and proportions compressed air, oxygen and helium, and stores the proportioned ternary mixed gas in the mixed gas storage tank; the human cabin is used for pressurization and decompression of the workers before and after working under pressure. An oronasal mask respirator and a thin film hood are set in the cabin. The oronasal mask respirator is connected to the mixed gas storage tank through a high-pressure hose, and the thin film hood is connected to the oxygen supply device through an air supply pipeline; the micro-pressure oxygen cabin is used to receive the workers for oxygen therapy after the decompression of the human cabin is completed.

[0007] Preferably, the air compressor module uses two 5.5KW oil-free air compressors, one for use and one for backup, to compress the air. After passing through a digital pressure controller, the compressed air is processed in sequence through a refrigerated dryer, a high-pressure precision filter and an adsorption dryer. The purified compressed air enters three parallel compressed air storage tanks with a volume of 1m³.

[0008] Preferably, when the pressure in the compressed air storage tank reaches 2MPa, the oil-free air compressor automatically stops; when the pressure in the compressed air storage tank is less than 1.8MPa, the oil-free air compressor automatically starts to ensure that the pressure in the compressed air storage tank is between 1.8MPa-2.0MPa.

[0009] Preferably, when the air supply valve of the compressed air storage tank is opened, the compressed air is filtered through an activated carbon filter and a precision filter, and transported to the air distribution exhaust through a use and a backup pipeline to provide compressed air for the automatic air distribution component and the manual air distribution component.

[0010] Preferably, the gas source cylinder group includes at least two groups of helium cylinder groups, one for use and one for backup, and three groups of oxygen cylinder groups, one for use and two for backup. After passing through the check valve, the helium and oxygen are connected to the helium gas distribution row and the oxygen gas distribution row, respectively, thereby providing helium and oxygen to the automatic gas distribution component and the manual gas distribution component, respectively.

[0011] Preferably, in the mixed gas distribution module, air, oxygen and helium pass through the pressure-stabilizing valve, transmitter, manual valve, filter, flow controller and check valve of the automatic gas distribution assembly, enter the No. 1 mixed gas row, adjust the pressure through the back pressure valve, flow into the No. 2 mixed gas row through two gas supply pipes, and finally reach the mixed gas storage tank. The No. 2 mixed gas row is connected to the manual gas distribution assembly.

[0012] Preferably, the volume of the mixed gas storage tank is 1m³. When the internal air pressure is greater than 9 bar, the pressure regulating and reducing valve automatically opens the high-pressure hose, and the mixed gas is monitored by the flow meter and gas analyzer to ensure that the gas composition meets the preset indicators before supplying gas to the oronasal mask respirator.

[0013] Preferably, the man cabin is connected to a pressurizing device of the shield machine, and the pressurizing device adjusts the pressure in the cabin by filling compressed air into the man cabin.

[0014] 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.

[0015] Preferably, in the ternary mixed gas, the partial pressure PO of oxygen is 1.4-2.0 ATA, the partial pressure PN of nitrogen is ≤4 ATA, and the rest is helium.

[0016] The beneficial effects of the present invention are as follows: The mixed gas shield pressure operation life support system provided by the present invention adopts a non-saturated high-pressure operation method. By eliminating the living cabin and the shuttle cabin, the operator can directly enter the human cabin for pressurization and wear a mouth-nasal mask respirator to inhale the helium-nitrogen-oxygen ternary mixture, which simplifies the operation process, shortens the operation cycle, makes breathing smoother, and significantly improves construction efficiency. As a device that supports this innovative operation method, the life support system organically integrates the air compressor unit module, compressed air storage tank, gas source bottle group, mixed gas distribution module, human cabin and micro-pressure oxygen cabin through a modular combination design. The organic integration between the modules improves the scalability and operational flexibility of the system, and constructs an efficient, stable and continuously operating life support platform. The mixed gas distribution module integrates automatic distribution components and manual distribution components. It can not only flexibly adjust the ratio of helium, nitrogen and oxygen as needed to achieve the precise preparation of the mixed gas required for the operation stage, but also has a redundant switching function, which effectively avoids the operation risks caused by gas source interruption. The independent sources and distribution paths of air, oxygen, and helium make the supply of ternary mixed gas more reliable, avoiding production interruptions caused by gas source bottle switching errors or supply fluctuations. The air compressor module automatically starts and stops through intelligent pressure control, and combines with parallel gas storage tanks to adjust the gas storage capacity to ensure the continuous output of compressed air while reducing energy consumption; the mixed gas storage tank is equipped with a pressure regulator, flow meter and gas analyzer to monitor the quality and supply status of the mixed gas in real time to ensure the stability and safety of the gas supply. The mixed gas shield pressure operation life support system has a compact overall design, reliable operation, and flexible gas production scheme. It not only meets the requirements of the mixed gas ratio for non-saturated high-pressure operation mode, but also significantly reduces helium consumption and overall operating costs, taking into account safety, economy and engineering practicality, and can provide a solid guarantee for continuous operation in deep buried and high-pressure working environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an overall schematic diagram of a life support system for mixed gas shield operation under pressure according to an embodiment of the present invention.

[0018] Figure numerals: 1-air compressor unit module; 2-compressed air storage tank; 3-gas source bottle group; 31-helium bottle group; 32-oxygen bottle group; 33-helium gas distribution row; 34-oxygen gas distribution row; 35-air gas distribution row; 4-mixed gas distribution module; 41-automatic gas distribution assembly; 42-manual gas distribution assembly; 43-mixed gas storage tank; 44-No. 1 mixed gas row; 45-back pressure valve; 46-No. 2 mixed gas row; 5-personnel cabin; 51-oral and nasal mask respirator; 52-thin membrane hood; 53-oxygen supply device; 54-exhaust valve; 6-micro-pressure oxygen chamber; 7-pressurization device. DETAILED DESCRIPTION

[0019] 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.

[0020] 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.

[0021] See also Figure 1This embodiment provides a life support system for mixed gas shield operation under pressure. The life support system adopts a modular combination design and is divided into multiple modules based on functional units, which is convenient for transportation, deployment and maintenance. It is suitable for non-saturated high-pressure operations, such as shield tool change under pressure. Saturated high-pressure operation refers to operation in an environment with a pressure higher than atmospheric pressure, with continuous exposure reaching or exceeding 24 hours, in which the body's tissues are saturated with inert gas. Non-saturated high-pressure operation means that the operator does not enter a saturated diving state in a high-pressure environment, thereby reducing the pressurization and decompression time and improving operation efficiency. The mixed gas shield pressure operation life support system includes an air compressor module 1, a compressed air storage tank 2, a gas source bottle group 3, a mixed gas distribution module 4, a human cabin 5 and a micro-pressure oxygen cabin 6; the air compressor module 1 stores the compressed and purified air in the compressed air storage tank 2, and the compressed air storage tank 2 is connected to the mixed gas distribution module 4 through a high-pressure pipeline to provide compressed air; the gas source bottle group 3 includes a helium cylinder group 31 and an oxygen cylinder group 32 in parallel, and the helium cylinder group 31 and the oxygen cylinder group 32 are medical high-pressure gas cylinders, which are respectively connected to the mixed gas distribution module 4 through high-pressure pipelines to provide oxygen and helium; the mixed gas distribution module 4 includes an automatic distribution component 41, a manual distribution component 42 and a mixed gas storage tank 43, and the automatic distribution component 41 and the manual distribution component 42 are used to perform automatic and manually controlled gas ratio adjustment tasks respectively, and mix the compressed air, oxygen and helium. The mixed ternary mixed gas passes through After pressure stabilization and testing, it enters the mixed gas storage tank 43. The mixed gas storage tank 43 is a medium-pressure container used for short-term buffer gas supply, and the proportioned ternary mixed gas is stored in the mixed gas storage tank 43; the human cabin 5 is used for pressurization and decompression of the operating personnel before and after pressurized work. The human cabin 5 is an airtight pressurized cabin, and an oronasal mask respirator 51 and a thin film hood 52 are installed in the cabin. The oronasal mask respirator 51 is connected to the mixed gas storage tank 43 through a high-pressure hose, and is used for the operating personnel to inhale the helium-nitrogen-oxygen ternary mixture during the pressurization, operation stage and the initial stage of decompression. The thin film hood 52 is connected to the oxygen supply device 53 through an air supply pipeline. The oxygen supply device 53 provides pure oxygen gas, which is used to replace the ternary mixture in the final stage of decompression; the micro-pressure oxygen chamber 6 is used to receive the operating personnel for oxygen therapy after the decompression of the human cabin 5 is completed. The micro-pressure oxygen chamber 6 maintains an ambient pressure of about 1.3ATA, which helps to continue to remove residual inert gases in the body, speed up the recovery process and reduce the risk of delayed decompression sickness.

[0022] Furthermore, the air compressor module 1 uses two 5.5KW oil-free air compressors, one in use and one in standby, to compress the air. The use of oil-free air compressors helps to ensure that the compressed air is clean and pollution-free, and prevents oil impurities from affecting the quality of the subsequent mixed gas. The one-in-use and one-standby configuration ensures system redundancy and improves the stability and reliability of continuous operation. After passing through the digital pressure controller, the compressed air is processed in sequence by a refrigerated dryer, a high-pressure precision filter, and an adsorption dryer. The refrigerated dryer is used to remove moisture generated during the compression process. The digital pressure controller is used to monitor the output pressure in real time to ensure that the pressure is stably output within the set range. The high-pressure precision filter and the adsorption dryer work together to remove particles and residual water vapor to ensure that the air is dry and pure. The purified compressed air enters three parallel compressed air storage tanks 2 with a volume of 1m³. The three parallel storage tanks provide sufficient gas volume buffer to ensure the continuity and stability of the gas supply. When the pressure in compressed air storage tank 2 reaches 2MPa, the oil-free air compressor automatically stops, and automatic start and stop are achieved through a pressure controller, without the need for manual intervention. When the pressure in compressed air storage tank 2 is less than 1.8MPa, the oil-free air compressor automatically starts to ensure that the pressure in compressed air storage tank 2 is between 1.8MPa and 2.0MPa, ensuring that the mixed gas distribution module 4 has a stable air source at all times. After the air supply valve of compressed air storage tank 2 is opened, the compressed air is filtered through an activated carbon filter and a precision filter. The activated carbon filter is used to further remove odors and residual organic matter, and the precision filter improves the air cleanliness level. The compressed air is then transported to the air distribution exhaust 35 through a one-in-one-standby pipeline. This one-in-one-standby configuration improves the redundancy and switching capabilities of the air supply pipeline, providing compressed air to the automatic air distribution component 41 and the manual air distribution component 42, ensuring stable air supply and backup guarantee for system operation.

[0023] In this embodiment, the gas source cylinder group 3 includes at least two helium cylinder groups 31, each with one in use and one in reserve, and three oxygen cylinder groups 32, each with one in use and two in reserve. The helium cylinder groups 31 and the oxygen cylinder groups 32 are high-pressure gas storage devices. The one-in-use, multiple-reserve configuration ensures uninterrupted gas supply. After passing through the check valves, the helium and oxygen are connected to the helium gas distribution row 33 and the oxygen gas distribution row 34, respectively. The check valves are used to prevent gas backflow and ensure a stable, one-way supply of gas. The helium gas distribution row 33 and the oxygen gas distribution row 34 are connected to their respective cylinder groups and realize gas source diversion, thereby providing helium and oxygen to the automatic gas distribution assembly 41 and the manual gas distribution assembly 42, respectively. This ensures that in the event of an automatic system failure, the manual system can be switched to maintain operation, thereby improving overall reliability.

[0024] In the mixed gas distribution module 4, air, oxygen, and helium pass through the pressure-stabilizing valve, transmitter, manual valve, filter, flow controller, and check valve of the automatic gas distribution assembly 41, which sequentially regulates pressure, monitors, adjusts flow, and prevents backflow. The air, oxygen, and helium then enter the No. 1 mixing row 44, which serves as the integrated node for the initial mixing of the three gases, ensuring a controlled mixing ratio. The pressure is regulated by the backpressure valve 45, which is used to stabilize the outlet pressure and prevent transient gas fluctuations from affecting the mixing effect. The air then flows into the No. 2 mixing row 46 through two gas supply pipes equipped with gas supply valves. The No. 2 mixing row 46 is connected to the manual gas distribution assembly 42, which is used for switching, relaying pressure regulation, and evenly distributing the mixed gas. The mixed gas ultimately reaches the mixed gas storage tank 43. The volume of the mixed gas storage tank 43 is 1m³, which provides a high-pressure reserve for the mixed gas and ensures continuous and reliable gas supply. When the internal air pressure is greater than 9 bar, the pressure-regulating and reducing valve automatically opens the high-pressure hose, and the control system outputs the gas in the mixed gas storage tank 43 at a stable pressure. The mixed gas is monitored by a flow meter and a gas analyzer. The flow meter ensures a constant gas supply rate, and the gas analyzer provides real-time feedback on the oxygen, nitrogen, and helium ratios of the mixed gas. After ensuring that the gas composition meets the preset indicators, gas is supplied to the oronasal mask respirator 51, ensuring the safety and physiological adaptability of the operating personnel breathing the ternary mixed gas in the human cabin 5.

[0025] During a shield machine's pressurized cutter-changing operation, the man cabin 5 serves as a pressurized space for workers to enter before the operation. It is directly connected to the mud and water chamber at the tunneling end of the shield machine. The man cabin 5 is connected to the shield machine's own pressurizing device 7, which regulates the cabin pressure by filling the man cabin 5 with compressed air. The pressurizing device 7 uses high-pressure air supply to initially establish the cabin pressure in the man cabin 5 and maintain the operating pressure, ensuring that the workers reach the required air pressure environment before entering the mud and water chamber. The man cabin 5 includes an air outlet valve 54, which opens after pressurization is completed. The air outlet valve 54 serves as a gas discharge and pressure regulating device in the man cabin 5. After the air pressure reaches a preset value, it releases excess gas, establishes an air balance between the inlet and outlet of the man cabin 5, ensures a constant cabin pressure, prevents cabin pressure fluctuations from affecting the physiological state of the workers, and stabilizes the air pressure at the set pressure, creating a safe and controllable environment for pressurized operations. After entering the man cabin 5, the operator wears a mouth-nose respirator 51, which is pressurized to the preset operating pressure. Then, the operator enters the mud and water tank from the man cabin 5 to perform the tool change operation. The operator works in a stable high-pressure environment in the mud and water tank. After completing the tool change, the operator returns to the man cabin 5 to prepare for subsequent decompression or evacuation.

[0026] In this embodiment, the partial pressure of oxygen in the ternary mixed gas is Po 1.4-2.0ATA, and the partial pressure of nitrogen is P N≤4 ATA, with the remainder being helium. This gas ratio balances oxygen demand during operations with inert gas desaturation efficiency. The oxygen partial pressure is controlled within the safe range for human metabolism, while the nitrogen partial pressure is limited to below 4 ATA to prevent high-pressure nitrogen narcosis. The remainder is supplemented by helium to reduce the mixture density and reduce breathing resistance, thereby ensuring safe and efficient life support during high-pressure operations. The ratio of the helium-nitrogen-oxygen ternary gas mixture not only considers respiratory safety and nitrogen narcosis risk control during operations, 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. This means that nitrogen partial pressure controls the dissolution and release of tissue gases in the decompression plan. This significantly shortens decompression time compared to traditional decompression models that use helium as the basis for the most unfavorable water depth. Due to helium's faster diffusion rate and more sensitive tissue saturation and desaturation processes, decompression planning based on helium requires longer step-by-step decompression to prevent bubble precipitation and decompression sickness. The present invention rationally controls the nitrogen partial pressure and limits it to below 4.0 ATA, which not only effectively avoids nitrogen narcosis, but also reduces the release control intensity of the most unfavorable tissue gas in the decompression path planning, thereby shortening the decompression time and improving the overall operation efficiency and the recovery speed of personnel after the operation.

[0027] In addition, a walkie-talkie and a tablet are installed in cabin 5. The walkie-talkie communicates with the control room and enables real-time voice communication between the operators in cabin 5 and the control room, facilitating two-way information transmission during various stages, such as pressurization, tool change, standby, and decompression. The tablet provides a means of transmitting text messages in situations of high noise, high pressure, or poor communication, enhancing information redundancy and safety during operations. An alarm device is also installed in cabin 5 to identify the operator's working status and transmit this information to the control room. The alarm device uses a sensor module to collect the operator's movement frequency, posture changes, respiratory airflow, or other physiological or behavioral parameters. Combined with pre-set state judgment logic, the alarm device can identify abnormal conditions such as loss of consciousness, abnormal breathing, or prolonged inactivity. Once an abnormality is detected, an alarm signal is sent to the control room, facilitating a prompt response from the on-duty personnel and improving safety management and control capabilities during high-pressure operations.

[0028] In a specific embodiment, when the pressure of the mixed gas storage tank 43 of the mixed gas distribution module 4 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 storage tank 43 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 51, 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 supplies gas to the operators according to the set gas supply volume. The intelligent flow control valve dynamically adjusts the gas flow rate according to the system settings and operator feedback to achieve precise gas supply control. 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.

[0029] In summary, the present invention discloses a life support system for pressure-assisted operation of a mixed gas shield machine. In summary, the present invention discloses a life support system for pressure-assisted operation of a mixed gas shield machine. The system adopts a modular combination design and is suitable for non-saturated high-pressure operation environments. It includes an air compressor module 1, a compressed air storage tank 2, a gas source bottle group 3, a mixed gas distribution module 4, a human cabin 5 and a micro-pressure oxygen cabin 6. The air compressor module 1 provides stable and clean compressed air through oil-free compression, drying and filtration processes. The gas source bottle group 3 provides helium and oxygen, and is respectively connected to the mixed gas distribution module 4 through the helium gas distribution row 33 and the oxygen gas distribution row 34. The mixed gas distribution module 4 is equipped with an automatic gas distribution component 41 and a manual gas distribution component 42. The three-element mixed gas is precisely adjusted through the No. 1 mixed gas row 44, the back pressure valve 45 and the No. 2 mixed gas row 46, and is stored in the mixed gas storage tank 43. The human chamber 5 is equipped with an oronasal mask respirator 51 and a thin membrane hood 52, providing a pressurized, operational, and decompressed environment for the operator. The micro-compression oxygen chamber 6 is used for continuous oxygen therapy after decompression, helping to consolidate the denitrification effect and restore physical fitness. Through the integrated management and precise proportioning of air, oxygen, and helium, this system achieves an efficient and stable supply of a ternary gas mixture, ensuring the continuity and composition stability of the gas supply during pressurized operations and avoiding operational risks caused by gas interruptions or imbalances. Furthermore, the system features two independent automatic and manual gas mixing paths, providing excellent redundancy and fault tolerance. Pressure, flow, and composition parameters are monitored throughout the gas supply process, and control elements such as the pressurization device 7 and the outlet valve 54 in the human chamber 5 are used to achieve precise and controllable pressurization and decompression operations. After decompression, the micro-compression oxygen chamber 6 is connected for oxygen therapy at 1.3 ATA, further reducing the risk of decompression sickness and improving personnel recovery efficiency. While ensuring operational safety, this hybrid gas shield life support system for pressurized operations significantly simplifies the reliance on multi-chamber systems for traditional saturated operations, reduces equipment size and operator workload, and optimizes the life support process. With its compact layout, reliable operation, and high degree of automation, the system is particularly well-suited for critical processes such as pressurized cutter changes and high-pressure inspections during deep-buried, long-distance shield construction. It provides strong life support for continuous and safe shield operations in high-pressure, complex formations, and has significant engineering promotion and industry application value.

[0030] 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 mixed gas shield pressure operation life support system, characterized in that: The life support system adopts a modular combination design and is suitable for non-saturated shield high-pressure operation, comprising an air compressor module (1), a compressed air storage tank (2), a gas source bottle group (3), a mixed gas distribution module (4), a human cabin (5) and a micro-pressure oxygen cabin (6); the air compressor module (1) stores compressed and purified air in the compressed air storage tank (2), and the compressed air storage tank (2) is connected to the mixed gas distribution module (4) through a high-pressure pipeline to provide compressed air; the gas source bottle group (3) includes a helium bottle group (31) and an oxygen bottle group (32) connected in parallel, which are respectively connected to the mixed gas distribution module (4) through a high-pressure pipeline to provide oxygen and helium; the mixed gas distribution module (4) includes an automatic gas distribution component (4 1), a manual gas distribution component (42) and a mixed gas storage tank (43), the automatic gas distribution component (41) or the manual gas distribution component (42) mixes and proportions compressed air, oxygen, and helium, and stores the proportioned ternary mixed gas in the mixed gas storage tank (43); the human cabin (5) is used for pressurization and decompression of the operator before and after the pressure work, and an oronasal mask respirator (51) and a film hood (52) are set in the cabin, the oronasal mask respirator (51) is connected to the mixed gas storage tank (43) through a high-pressure hose, and the film hood (52) is connected to the oxygen supply device (53) through an air supply pipeline; the micro-pressure oxygen cabin (6) is used to receive the operator for oxygen therapy after the decompression of the human cabin is completed; the partial pressure P of oxygen in the ternary mixed gas is 1. O 1.4-2.0ATA, nitrogen partial pressure P N ≤4ATA, the rest is helium, and nitrogen is used as the inert gas basis for judging the most unfavorable water depth in the mixed gas ratio; the life support system does not require the setting of a living cabin and a shuttle cabin, and the operating personnel can directly enter the human cabin (5) for pressurization. After entering the human cabin (5), the operating personnel wear a mouth and nose mask respirator (51), pressurized to a preset operating pressure, and then enter the mud and water cabin from the human cabin (5) to perform a knife change operation. The operation is in a stable high-pressure environment in the mud and water cabin. After completing the knife change, the operating personnel return to the human cabin (5) to prepare for subsequent decompression or evacuation.

2. The mixed gas shield pressure operation life support system according to claim 1 is characterized in that: The air compressor module (1) uses two 5.5KW oil-free air compressors, one for use and one for backup, to compress air. The compressed air passes through a digital pressure controller and then sequentially through a refrigeration dryer, a high-pressure precision filter, and an adsorption dryer. The purified compressed air then enters three parallel-connected compressed air storage tanks (2) with a capacity of 1m3.

3. The mixed gas shield pressure operation life support system according to claim 2 is characterized in that: When the pressure of the compressed air storage tank (2) reaches 2MPa, the oil-free air compressor automatically stops; when the pressure in the compressed air storage tank (2) is less than 1.8MPa, the oil-free air compressor automatically starts to ensure that the pressure of the compressed air storage tank (2) is between 1.8MPa and 2.0MPa.

4. The mixed gas shield pressure operation life support system according to claim 3 is characterized in that: When the air supply valve of the compressed air storage tank (2) is opened, the compressed air is filtered by an activated carbon filter and a precision filter, and is transported to the air distribution exhaust (35) through a service pipeline and a backup pipeline to provide compressed air for the automatic air distribution component (41) and the manual air distribution component (42).

5. The mixed gas shield pressure operation life support system according to claim 1 is characterized in that: The gas source cylinder group (3) includes at least two helium cylinder groups (31) with one in use and one in reserve and three oxygen cylinder groups (32) with one in use and two in reserve. After passing through the check valve, the helium and oxygen are connected to the helium gas distribution row (33) and the oxygen gas distribution row (34), respectively, so as to provide helium and oxygen to the automatic gas distribution component (41) and the manual gas distribution component (42), respectively.

6. The mixed gas shield pressure operation life support system according to claim 1 is characterized in that: In the mixed gas distribution module (4), air, oxygen and helium pass through the pressure regulating valve, transmitter, manual valve, filter, flow controller and check valve of the automatic gas distribution assembly (41), enter the No. 1 mixed gas row (44), adjust the pressure through the back pressure valve (45), flow into the No. 2 mixed gas row (46) through two gas supply pipes, and finally reach the mixed gas storage tank (43). The No. 2 mixed gas row (46) is connected to the manual gas distribution assembly (42).

7. The mixed gas shield pressure operation life support system according to claim 1 is characterized in that: The volume of the mixed gas storage tank (43) is 1m³. When the internal air pressure is greater than 9 bar, the pressure regulating and reducing valve automatically opens the high-pressure hose, and the mixed gas is monitored by a flow meter and a gas analyzer to ensure that the gas composition meets the preset indicators before supplying gas to the oronasal mask respirator (51).

8. The mixed gas shield pressure operation life support system according to claim 1 is characterized in that: The man cabin (5) is connected to a pressurizing device (7) provided with the shield machine, and the pressurizing device (7) regulates the pressure in the cabin by injecting compressed air into the man cabin (5).

9. The mixed gas shield pressure operation life support system according to claim 8, characterized in that: The human cabin (5) includes an air outlet valve (54). After pressurization is completed, the air outlet valve (54) is opened to establish an air inlet and outlet balance of the human cabin (5), and the air pressure is stabilized at a set pressure.

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