Life support system for mixed gas shield operation under pressure

Abstract

The invention discloses a life support system for mixed gas shield under-pressure operation, which is suitable for unsaturated shield high-pressure operation and comprises an air compressor unit module, a compressed air storage tank, an air source bottle group, a mixed gas distribution module, a human cabin and a micro-pressure oxygen cabin, the air compressor unit module stores compressed and purified air in a compressed air storage tank; the gas source bottle group comprises a helium bottle group and an oxygen bottle group which are connected in parallel; the mixed gas distribution module comprises an automatic gas distribution assembly, a manual gas distribution assembly and a mixed gas storage tank and is used for mixing and proportioning compressed air, oxygen and helium; the man cabin is used for pressurizing and depressurizing before and after working with pressure of an operator, and a mouth-nose mask respirator and a thin film hood are arranged in the cabin; and the micro-pressure oxygen cabin is used for receiving the operating personnel for oxygen therapy after the decompression of the human cabin is completed. A living cabin and a shuttle cabin are omitted, efficient linkage of the air source modules and the human cabin is achieved in a modular integration mode, and the working efficiency and safety in the high-pressure working environment are improved.

Description

Technical Field

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

[0002] Currently, the shield pressure operation mainly includes two modes: air pressure operation and helium-oxygen saturation operation. For relatively shallow or medium-depth operation conditions, compressed air environment operation is often adopted. Personnel perform short-term operations in a high-pressure environment through a nose and mouth mask respirator and rely on a traditional decompression chamber to complete the decompression process after the operation. In deeper tunnel environments, to meet higher pressure adaptation requirements, helium-oxygen saturation diving operation mode is often adopted. Such operations require multiple functional cabins such as a saturation diving cabin, a shuttle cabin, and a living cabin. Operators need to experience long-term pressurization, operation, and decompression processes, breathe a helium-oxygen mixture to control the risks of nitrogen narcosis and oxygen poisoning, and control the desaturation rate of inert gases through a staged decompression strategy. Due to the involvement of multiple cabins, the setting quantity, configuration method, and gas regulation of mixed gas cylinders, oxygen cylinders, and helium cylinders are also relatively complex, resulting in a cumbersome operation process and a large management difficulty.

[0003] However, the existing helium-oxygen saturation pressure operation system has many deficiencies. First, the structure of such a system is complex, with a large number of cabins, a large occupied space, a low system integration degree, and its operation depends on a large number of devices and requires occupying the limited space in the backfield of the shield. Second, as a rare gas, helium has a large consumption, resulting in a high usage cost, especially in long-term high-pressure operations, the economic burden is even heavier. Third, helium-oxygen saturation operations are usually only suitable for long-term, high-depth continuous operations and are not suitable for the operation requirements with short cycles and frequent tool changing. The overall efficiency is low and the response is slow, unable to meet the requirements of modern tunnel rapid construction. In addition, if the decompression operation of operators in saturation operations is not properly controlled, serious physiological reactions such as decompression sickness are extremely likely to occur, with a high safety risk and a very high dependence on operation specifications and operation environment stability. Therefore, the existing life support system urgently needs to be optimized and innovated in terms of structural design, gas distribution method, safety control, operation efficiency, etc. to adapt to the shield pressure tool changing environment with deep burial, high pressure, and fast rhythm. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention proposes a life support system for mixed gas shield pressure operation, which cancels the traditional living cabin and shuttle cabin structures, and realizes the efficient linkage between each gas source module and the human cabin through a modular integration method, improving the work efficiency and safety in a high-pressure pressure operation environment.

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

[0006] A life support system for pressure operation of a mixed gas shield tunneling machine. The life support system adopts a modular combination design and is applicable to unsaturated high-pressure operations. It includes an air compressor unit module, a compressed air storage tank, a gas source bottle group, a mixed gas distribution module, a personnel cabin, and a micro-pressure oxygen cabin. The air compressor unit module stores the compressed and purified air in the compressed air storage tank. 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 parallel-connected helium gas bottle group and an oxygen gas bottle group, 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 the compressed air, oxygen, and helium, and stores the proportioned ternary mixed gas in the mixed gas storage tank. The personnel cabin is used for pressurization and decompression before and after the pressure operation of the operators. A nose and mouth mask respirator and a thin film hood are arranged in the cabin. The nose and mouth mask respirator is connected to the mixed gas storage tank through a high-pressure hose, and the thin film hood is connected to an oxygen supply device through an air supply pipeline. The micro-pressure oxygen cabin is used to receive the operators for oxygen therapy after the decompression of the personnel cabin is completed.

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

[0008] Preferably, when the pressure of 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 of the compressed air storage tank is between 1.8MPa and 2.0MPa.

[0009] Preferably, after the air supply valve of the compressed air storage tank is opened, the compressed air is further filtered by an activated carbon filter and a precision filter, and is transported to an air distribution manifold through a one-in-use and one-in-standby pipeline to provide compressed air for the automatic gas distribution component and the manual gas distribution component.

[0010] Preferably, the gas source bottle group includes at least two groups of helium gas bottle groups, one in use and one in standby, and three groups of oxygen gas bottle groups, one in use and two in standby. After passing through check valves, helium and oxygen are respectively connected to a helium gas distribution manifold and an oxygen gas distribution manifold, so as to provide helium and oxygen for 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 mixing row, adjust the pressure through the back pressure valve, flow into the No. 2 mixing row through two gas supply pipes, and finally reach the mixed gas storage tank. The No. 2 mixing 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 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.

[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 of 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 1.4-2.0ATA, the partial pressure PN of nitrogen is ≤4ATA, and the rest is helium.

[0016] The beneficial effects of the present invention are as follows: The life support system for the pressurized operation of the mixed gas shield tunneling machine provided by the present invention adopts the unsaturated high-pressure operation mode. By canceling the living cabin and the shuttle cabin, the operators can directly enter the personnel cabin for pressurization and wear a nose and mouth mask respirator to inhale the ternary mixed gas of helium, nitrogen, and oxygen, which simplifies the operation process, shortens the operation cycle, makes breathing smoother, and significantly improves the construction efficiency. As the equipment to support this innovative operation mode, the life support system organically integrates the air compressor unit module, compressed air storage tank, gas source bottle group, mixed gas distribution module, personnel cabin, and micro-pressure oxygen cabin through modular combination design. The organic integration between modules improves the scalability and operation flexibility of the system, and constructs an efficient, stable, and continuously operating life support platform. The mixed gas distribution module integrates an automatic gas distribution component and a manual gas distribution component, which can not only flexibly adjust the ratio of the three gases of helium, nitrogen, and oxygen according to needs to achieve the precise preparation of the mixed gas required in the operation stage, but also has a redundant switching function to effectively avoid the operation risks caused by the interruption of the gas source. The independent sources and distribution paths of air, oxygen, and helium make the supply of the ternary mixed gas more reliable and avoid production interruption problems caused by mistakes in switching gas source bottles or supply fluctuations. The air compressor unit module automatically starts and stops through intelligent pressure control, and combines parallel storage tanks to adjust the 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, a flow meter, and a gas analyzer to monitor the quality and supply status of the mixed gas in real time to ensure the stability and safety of gas supply. The life support system for the pressurized operation of the mixed gas shield tunneling machine has a compact overall design, reliable operation, and flexible gas production scheme. It not only meets the requirements of the unsaturated high-pressure operation mode for the ratio of the mixed gas, but also significantly reduces the helium consumption and the overall operation cost, taking into account safety, economy, and engineering practicability, and can provide a solid guarantee for continuous operation in deep-buried and high-pressure operation environments. Description of the Drawings

[0017] Figure 1 It is the overall schematic diagram of the life support system for the pressurized operation of the mixed gas shield tunneling machine in the embodiment of the present invention.

[0018] Reference Signs: 1 - air compressor unit module; 2 - compressed air storage tank; 3 - gas source bottle group; 31 - helium gas bottle group; 32 - oxygen gas bottle group; 33 - helium gas distribution row; 34 - oxygen gas distribution row; 35 - air distribution row; 4 - mixed gas distribution module; 41 - automatic gas distribution component; 42 - manual gas distribution component; 43 - mixed gas storage tank; 44 - first mixed gas row; 45 - back pressure valve; 46 - second mixed gas row; 5 - personnel cabin; 51 - nose and mouth mask respirator; 52 - thin film headgear; 53 - oxygen supply device; 54 - outlet valve; 6 - micro-pressure oxygen cabin; 7 - pressurizing device. Detailed Embodiments

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a 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 those of ordinary skill in the art belong to the present invention.

[0020] In addition, the described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present application. However, those skilled in the art will realize that the technical solutions of the present application may be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be used. In other cases, well-known methods, devices, implementations or operations are not shown or described in detail to avoid obscuring aspects of the present application.

[0021] Please refer to Figure 1, this embodiment provides a life support system for the pressure - working of a mixed - gas shield tunneling machine. This life support system adopts a modular combination design, divides multiple modules based on functional units, which is convenient for transportation, deployment, and maintenance, and is applicable to non - saturated high - pressure operations, such as pressure - working tool changing of the shield tunneling machine. Saturated high - pressure operation refers to working in an environment above atmospheric pressure, with continuous exposure reaching or exceeding 24 h, and all tissues of the body being saturated with inert gas. Non - saturated high - pressure operation means that the operator does not enter the state of saturation diving in the high - pressure environment, thereby reducing the pressurization and decompression time and improving the operation efficiency. The life support system for the pressure - working of a mixed - gas shield tunneling machine includes an air compressor unit module 1, a compressed air storage tank 2, a gas source bottle group 3, a mixed - gas mixing module 4, a personnel cabin 5, and a micro - pressure oxygen chamber 6. The air compressor unit module 1 stores the compressed and purified air in the compressed air storage tank 2. The compressed air storage tank 2 is connected to the mixed - gas mixing module 4 through a high - pressure pipeline to provide compressed air. The gas source bottle group 3 includes a parallel - connected helium gas bottle group 31 and an oxygen gas bottle group 32. The helium gas bottle group 31 and the oxygen gas bottle group 32 are medical high - pressure gas bottles, which are respectively connected to the mixed - gas mixing module 4 through high - pressure pipelines to provide oxygen and helium. The mixed - gas mixing module 4 includes an automatic gas mixing component 41, a manual gas mixing component 42, and a mixed - gas storage tank 43. The automatic gas mixing component 41 and the manual gas mixing component 42 are used to perform the gas ratio adjustment tasks of automatic and manual control respectively, mix and proportion the compressed air, oxygen, and helium. The mixed ternary mixed gas enters the mixed - gas storage tank 43 after pressure stabilization and detection. The mixed - gas storage tank 43 is a medium - pressure container for short - term buffer gas supply, and stores the proportioned ternary mixed gas. The personnel cabin 5 is used for pressurization and decompression before and after the operator's pressure - working. The personnel cabin 5 is an airtight pressurized cabin body, and a nose - mouth mask respirator 51 and a thin - film headgear 52 are arranged inside the cabin. The nose - mouth mask respirator 51 is connected to the mixed - gas storage tank 43 through a high - pressure hose and is used for the operator to inhale the ternary helium - nitrogen - oxygen mixed gas during the pressurization, operation stage, and initial decompression stage. The thin - film headgear 52 is connected to an oxygen supply device 53 through an air supply pipeline. The oxygen supply device 53 provides pure oxygen gas and is used to replace the ternary mixed gas during the final decompression stage. The micro - pressure oxygen chamber 6 is used to receive the operator for oxygen therapy after the decompression of the personnel cabin 5. The micro - pressure oxygen chamber 6 maintains an environmental pressure of about 1.3 ATA, which helps to continue to remove the residual inert gas in the body, accelerate the recovery process, and reduce the risk of delayed decompression sickness.

[0022] Furthermore, the air compressor unit module 1 uses two 5.5KW oil-free air compressors, one in use and one in standby, to compress air. Using oil-free air compressors is beneficial to ensuring that the compressed air is clean and pollution-free, avoiding the influence of oil and impurity components on the quality of the subsequent mixed gas. The one-in-use-one-in-standby configuration ensures system redundancy and improves the stability and reliability of continuous operation. After passing through the digital display pressure controller, the compressed air is sequentially processed by a refrigerated dryer, a high-pressure precision filter, and an adsorption dryer. The refrigerated dryer is used to remove the moisture generated during the compression process. The digital display 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 jointly 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 1 m³. The three parallel storage tanks provide sufficient gas volume buffering to ensure the continuity and stability of gas supply. When the pressure of the compressed air storage tank 2 reaches 2 MPa, the oil-free air compressor automatically stops. The automatic start and stop are realized through the pressure controller without manual intervention. When the pressure in the compressed air storage tank 2 is less than 1.8 MPa, the oil-free air compressor automatically starts to ensure that the pressure of the compressed air storage tank 2 is between 1.8 MPa and 2.0 MPa, ensuring that the mixed gas distribution module 4 can obtain a stable gas source at any time. After the gas supply valve of the compressed air storage tank 2 is opened, the compressed air is further filtered by an activated carbon filter and a precision filter. The activated carbon filter is used to further remove odors and residual organic substances, and the precision filter improves the air cleanliness level. It is transported to the air distribution manifold 35 through a one-in-use-one-in-standby pipeline. The one-in-use-one-in-standby configuration improves the redundancy and switching ability of the gas supply pipeline, provides compressed air for the automatic gas distribution component 41 and the manual gas distribution component 42, and realizes stable gas supply and standby guarantee for the system operation.

[0023] In this embodiment, the gas source bottle group 3 includes at least two groups of helium gas bottle groups 31 with one in use and one in standby and three groups of oxygen gas bottle groups 32 with one in use and two in standby. The helium gas bottle group 31 and the oxygen gas bottle group 32 are high-pressure gas storage devices. The one-in-use-multiple-in-standby configuration ensures uninterrupted gas supply. After passing through the check valve, helium and oxygen are respectively connected to the helium gas distribution manifold 33 and the oxygen gas distribution manifold 34. The check valve is used to prevent gas backflow and ensure stable unidirectional gas supply. The helium gas distribution manifold 33 and the oxygen gas distribution manifold 34 are connected to their respective bottle groups and realize gas source shunting, so as to provide helium and oxygen for the automatic gas distribution component 41 and the manual gas distribution component 42 respectively, ensuring that the manual system can be switched to maintain operation in case of an automatic system failure and improving the overall reliability.

[0024] 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 component 41, and adjust the pressure, monitor, adjust the flow and prevent backflow in turn, and enter the No. 1 mixed gas row 44. The No. 1 mixed gas row 44 is an integrated node for the first mixing of the three gases to ensure that the mixing ratio is controlled. The pressure is adjusted by the back pressure valve 45, which is used to stabilize the outlet pressure to prevent the instantaneous fluctuation of the gas from affecting the mixing effect. It flows into the No. 2 mixed gas row 46 through two gas supply pipes. The gas supply pipes are equipped with gas supply valves. The No. 2 mixed gas row 46 is connected to the manual gas distribution component 42 for switching, relay pressure regulation and uniform distribution of the mixed gas. The mixed gas finally 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 to ensure 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, and monitors the mixed gas through the flow meter and 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 ratio of the mixed gas to ensure that the gas composition meets the preset indicators before supplying gas to the oronasal mask respirator 51, thereby ensuring the safety and physiological adaptability of the operating personnel breathing the ternary mixed gas in the man cabin 5.

[0025] In the shield machine's pressurized cutter changing operation, the man cabin 5 is directly connected to the mud and water cabin at the tunneling end of the shield machine as the pressurized space for the workers to enter before the operation. The man cabin 5 is connected to the pressurizing device 7 of the shield machine. The pressurizing device 7 adjusts the cabin pressure by filling compressed air into the man cabin 5. The pressurizing device 7 realizes the initial establishment of the cabin pressure of the man cabin 5 and the maintenance of the operating pressure through high-pressure air supply, ensuring that the workers reach the required air pressure environment before entering the mud and water cabin. The man cabin 5 includes an air outlet valve 54, which is opened after the 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 the preset value, it can release excess gas, establish the inlet and outlet balance of the man cabin 5, ensure the constant pressure in the cabin, prevent the cabin pressure fluctuation from affecting the physiological state of the workers, and stabilize 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 mask 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 changing operation, and operates in a stable high-pressure environment in the mud and water tank. After completing the tool changing, the operator returns to the man cabin 5 to prepare for subsequent decompression or evacuation.

[0026] In this embodiment, the partial pressure Po of oxygen in the ternary mixed gas is 1.4-2.0 ATA, and the partial pressure P of nitrogen is N≤4 ATA, with the rest being helium. This gas ratio takes into account both the oxygen supply demand during operation and the desaturation efficiency of inert gases. The partial pressure of oxygen is controlled within the safe range of human metabolism, and the partial pressure of nitrogen is limited below 4 ATA to prevent hyperbaric nitrogen narcosis. The rest is supplemented with helium to reduce the density of the mixed gas and respiratory resistance, thereby achieving safe and efficient life support during high-pressure operations. The ratio of the helium-nitrogen-oxygen ternary mixed gas not only considers the respiratory safety during operation and the control of nitrogen narcosis risk but also comprehensively considers the decompression efficiency after the operation. Specifically, nitrogen is used as the basis for judging the most adverse water depth of inert gases in the mixed gas ratio, that is, the partial pressure of nitrogen is used as the control factor for the dissolution and release of tissue gases in the decompression plan. Compared with the traditional decompression model based on helium as the basis for the most adverse water depth, it can significantly shorten the decompression time. Since the diffusion rate of helium is faster and the tissue saturation and desaturation processes are more sensitive, if the decompression design is based on helium, a longer stepwise decompression time is required to avoid the occurrence of decompression sickness caused by bubble precipitation. However, in the present invention, by reasonably controlling the partial pressure of nitrogen and limiting it below 4.0 ATA, not only is nitrogen narcosis effectively avoided, but also the release control intensity of the most adverse tissue gas is reduced in the decompression path planning, thereby shortening the decompression duration, improving the overall operation efficiency, and the recovery speed of personnel after the operation.

[0027] In addition, an intercom and a writing board are provided in the personnel cabin 5. The intercom communicates with the control room and is used to achieve real-time voice communication between the operators in the personnel cabin 5 and the control room, facilitating two-way information transmission in different stages such as pressurization, tool change, standby, and decompression. The writing board is used to provide a means of text information transmission in case of high noise, high pressure, or poor communication, enhancing information redundancy and safety during the operation process. An alarm device is also provided in the personnel cabin 5. The alarm device is used to identify the working state of the operator and upload the working state information to the control room. The alarm device can collect the action frequency, posture change, respiratory airflow, or other physiological or behavioral parameters of the operator through the sensor module, and combine the preset state judgment logic to identify abnormal states such as loss of consciousness, abnormal breathing, or long-term stillness. Once an abnormality is identified, an alarm signal is sent to the control room, facilitating the on-duty personnel to respond immediately and improving the safety control ability 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 above 9 Bar, the pressure is regulated between 8.5 - 8.7 Bar through the supply - air pressure regulator. The mixed - gas storage tank 43, as a storage device for the mixed gas, requires the internal gas pressure to reach a certain value to meet the subsequent stable - supply demand. The supply - air pressure regulator is used to adjust the high - pressure gas in the tank to the working - pressure range suitable for the nasal - mask respirator 51, ensuring supply - air safety and stable flow. After real - time monitoring by the gas analyzer and confirmation that the composition and parameters meet the requirements, after opening the supply - air valve, the gas is divided into four paths through the mixed - gas flow detector. The gas analyzer real - time detects the consistency between the volume fractions of the helium, nitrogen, and oxygen ternary mixed gas and the set values. Only after confirming no deviation can the supply - air valve be started. The mixed - gas flow detector divides the mixed gas into four, adapting to multiple operators or multi - point supply scenarios, and supplies gas to the operators according to the set gas supply volume through the intelligent flow regulator. The intelligent flow regulator dynamically adjusts the gas flow rate according to the system settings and the feedback from the operators to achieve precise supply - air control. In this embodiment, the preset operation pressure is 5.7 bar, and the overall pressurization duration is 5 min. The preset operation pressure is the minimum pressure condition required for the operator to overcome the water and soil pressure when entering the mud chamber and ensure operation safety. 5 min is the time required to pressurize from normal pressure to the operation pressure, and the operation - preparation time is shortened as much as possible within the safety - allowed range. For the ternary mixed gas, the nitrogen partial pressure is set at 2.9 ATA, the oxygen partial pressure is 1.6 ATA, and the helium partial pressure is 2.2 ATA. The three gas partial pressures are precisely controlled. The nitrogen partial pressure is strictly controlled below 4.0 ATA to effectively avoid the risk of high - pressure nitrogen narcosis. The oxygen partial pressure is maintained within the safe range of human metabolism, and the helium partial pressure is used to reduce the density and breathing resistance of the mixed gas. The operation residence time is 70 min, that is, the continuous operation time of the operator in the mud chamber under the high - pressure mixed - gas breathing environment. This time is set in combination with the tool - changing operation task volume and the personnel's pressure - bearing endurance, avoiding overtime exposure while ensuring the task is completed.

[0029] In summary, the present invention discloses a life support system for mixed gas shield under pressure operation. In summary, the present invention discloses a life support system for mixed gas shield under pressure operation. The system adopts a modular combination design and is suitable for non-saturated high-pressure working environment, including 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 connected to the mixed gas distribution module 4 through the helium gas distribution row 33 and the oxygen gas distribution row 34 respectively. The mixed gas distribution module 4 is equipped with an automatic gas distribution component 41 and a manual gas distribution component 42. The three-way mixed gas is accurately adjusted through the No. 1 mixed gas row 44, the back pressure valve 45 and the No. 2 mixed gas row 46, and stored in the mixed gas storage tank 43. The human cabin 5 is equipped with an oronasal mask respirator 51 and a thin film hood 52 to provide a pressurized, operational and decompressed environment for the operators. The micro-pressure oxygen chamber 6 is used for continuous oxygen therapy after decompression, which helps to consolidate the denitrification effect and restore physical fitness. Through the integrated management and precise proportioning of air, oxygen and helium, this system can achieve efficient and stable supply of ternary mixed gas, ensure the continuity of gas supply and component stability during pressurized operations, and avoid operational risks caused by gas interruption or imbalance in proportion. At the same time, the system has two independent automatic and manual paths for gas mixing, with good redundancy and fault tolerance; the pressure, flow and component parameters are monitored throughout the gas supply process, and the pressurization device 7, the outlet valve 54 and other control components in the human cabin 5 are used to achieve precise and controllable pressurization and decompression operations; after decompression, the micro-pressure oxygen chamber 6 is connected to carry out oxygen therapy under 1.3ATA, further reducing the risk of decompression sickness and improving the efficiency of personnel recovery. The mixed gas shield pressure operation life support system greatly simplifies the reliance of traditional saturated operations on multi-chamber systems on the basis of ensuring operation safety, reduces equipment volume and personnel operation intensity, and optimizes the life support process. The system has a compact layout, reliable operation, and a high degree of automation. It is particularly suitable for key processes such as pressure tool change and high-pressure inspection in deep-buried and long-distance shield construction. It provides strong life support for the continuous and safe operation of shield construction in high-pressure complex strata, and has significant engineering promotion value and industry application significance.

[0030] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A life support system for the pressurized operation of a mixed gas shield tunneling machine, characterized in that, The life support system adopts a modular combined design and is applicable to the high-pressure operation of non-saturated shield tunneling. It includes an air compressor unit module (1), a compressed air storage tank (2), a gas source bottle group (3), a mixed gas distribution module (4), a personnel cabin (5), and a micro-pressure oxygen cabin (6). The air compressor unit module (1) stores the compressed and purified air in the compressed air storage tank (2). 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 parallel-connected helium gas bottle group (31) and an oxygen gas bottle group (32), 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 gas distribution component (41), 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 personnel cabin (5) is used for pressurization and decompression before and after the pressure work of the operators. A nose and mouth mask respirator (51) and a thin film hood (52) are arranged in the cabin. The nose and mouth mask respirator (51) is connected to the mixed gas storage tank (43) through a high-pressure hose, and the thin film hood (52) is connected to an oxygen supply device (53) through an air supply pipeline. The micro-pressure oxygen cabin (6) is used to receive the operators for oxygen therapy after the decompression of the personnel cabin is completed.

2. The life support system for pressure operation of a mixed gas shield tunneling machine according to claim 1, wherein The air compressor unit module (1) uses two 5.5KW oil-free air compressors, one in use and one in reserve, to compress air. After passing through a digital display pressure controller, the compressed air is sequentially processed by a refrigerated dryer, a high-pressure precision filter, and an adsorption dryer. The purified compressed air enters three parallel compressed air storage tanks (2) with a volume of 1m 3 .

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

4. The life support system for pressure operation of a mixed gas shield tunneling machine according to claim 3, characterized in that, After 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 manifold (35) through a one-use-one-backup pipeline to provide compressed air for the automatic gas distribution component (41) and the manual gas distribution component (42).

5. The life support system for the pressure operation of a mixed gas shield tunneling machine according to claim 1, wherein The gas source bottle group (3) includes at least two groups of one-use-one-backup helium gas bottle groups (31) and three groups of one-use-two-backup oxygen gas bottle groups (32). After passing through check valves, helium and oxygen are respectively connected to the helium gas distribution manifold (33) and the oxygen gas distribution manifold (34), so as to provide helium and oxygen for the automatic gas distribution component (41) and the manual gas distribution component (42) respectively.

6. The life support system for the mixed gas shield tunneling operation under pressure according to claim 1, wherein, In the mixed gas distribution module (4), air, oxygen, and helium enter the first mixed gas manifold (44) through the pressure stabilizing valve, transmitter, manual valve, filter, flow controller, and check valve of the automatic gas distribution component (41), are regulated in pressure by a back pressure valve (45), flow into the second mixed gas manifold (46) through two air supply pipelines, and finally reach the mixed gas storage tank (43). The second mixed gas manifold (46) is connected to the manual gas distribution component (42).

7. The life support system for working under pressure of a mixed gas shield tunneling machine according to claim 1, characterized in that, The volume of the mixed gas storage tank (43) is 1m³. When the internal gas 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 life support system for pressure operation of a mixed gas shield tunneling machine according to claim 1, characterized in that, The man cabin (5) is connected to a pressurizing device (7) provided on the shield machine, and the pressurizing device (7) adjusts the pressure inside the cabin by filling the man cabin (5) with compressed air.

9. The life support system for working under pressure of a mixed gas shield tunneling machine according to claim 8, characterized in that, The man cabin (5) comprises an air outlet valve (54), and after pressurization is completed, the air outlet valve (54) is opened to establish an air inlet and outlet balance of the man cabin (5), and the air pressure is stabilized at a set pressure.

10. The life support system for working under pressure of a mixed gas shield tunneling machine according to claim 1, characterized in that, The partial pressure P of oxygen in the ternary gas mixture O is 1.4 - 2.0 ATA, the partial pressure P of nitrogen N ≤ 4 ATA, and the rest is helium.

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