Hollow fiber membrane nitrogen-oxygen gas separation and gas mixing intelligent regulation and control device

Abstract

The invention relates to the technical field of gas separation and intelligent control, in particular to a hollow fiber membrane nitrogen-oxygen gas separation and mixed gas intelligent regulation and control device which is characterized in that an air pretreatment module outputs pure stable-pressure compressed air; the hollow fiber membrane separation module is used for separating high-concentration nitrogen and high-concentration oxygen through gas permeation rate differences of different hollow fiber membranes; the gas mixing module receives high-concentration nitrogen and high-concentration oxygen, the high-concentration nitrogen and the high-concentration oxygen are uniformly mixed according to a preset proportion, and nitrogen-oxygen mixed gas meeting training requirements is generated; the expiration resistance adjusting module provides adjustable expiration confrontation resistance for training and adapts to two training modes of normal-pressure breathing and pressurized breathing. The intelligent control module collects operation parameters of all modules of the device, and gas concentration, flow and pressure requirements required by training are matched through a precise regulation and control algorithm. The gas path system is used for connecting all functional modules to guarantee stable transmission of gas. Therefore, the problems that in the prior art, air source dependence is high, and bottled air sources need to be replaced frequently in training are solved.

Description

Technical Field

[0001] This invention relates to the field of gas separation and intelligent control technology, specifically to a hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device. Background Technology

[0002] Before operating in special environments such as aviation, deep sea, and high-altitude areas, personnel need to undergo progressive acclimatization training to improve their hypoxia tolerance and environmental adaptability. For example, high-altitude flight personnel need to undergo hypoxia tolerance training and pressurized breathing training, while deep-sea workers also need to simulate hypoxia and pressure change environments. One of the core pieces of equipment for this type of training is a mixed gas supply device capable of continuously providing a specific oxygen concentration, flow rate, and pressure. Currently, the commonly used gas supply scheme mainly relies on bottled high-pressure gas sources. That is, pure oxygen and pure nitrogen stored in high-pressure steel cylinders are reduced to the working pressure by a pressure reducing valve, and then mixed by the control system according to a preset concentration ratio. Then, closed-loop regulation is performed using pressure, flow rate, and oxygen concentration sensors to finally output a stable airflow that meets the training requirements. Although this technology is relatively mature and can achieve gas concentration and flow rate control within a certain range, its overall system is highly dependent on the continuous supply of bottled oxygen and nitrogen.

[0003] However, the bottled gas supply model has several significant limitations. First, in remote areas, high-altitude regions, or resource-scarce locations, the acquisition, transportation, and storage costs of bottled gas are high, and the stability of the supply is difficult to guarantee, causing training equipment to malfunction due to gas supply interruptions. Second, frequent cylinder replacements not only increase operational complexity and labor costs but may also introduce safety hazards during handling and installation. Third, bottled gas itself is a high-pressure hazardous material, and its storage and use must adhere to strict safety regulations, further limiting the convenient deployment and flexible use of equipment. Therefore, existing technical solutions are significantly insufficient in terms of gas source versatility, equipment portability, and economic efficiency, making it difficult to meet the needs of diverse and highly mobile training scenarios. Therefore, there is an urgent need for a new type of gas supply device that can directly utilize ambient air as a raw material gas source, achieve on-site, on-demand preparation of nitrogen-oxygen mixed gas, and possess intelligent and precise control capabilities. Summary of the Invention

[0004] This application provides a hollow fiber membrane nitrogen and oxygen gas separation and mixing intelligent control device to solve the problems of strong gas source dependence and frequent replacement of bottled gas sources during training in the prior art.

[0005] This application provides a hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device, comprising: an air pretreatment module for filtering, compressing, cooling, and removing impurities from external air to output pure, stable-pressure compressed air; a hollow fiber membrane separation module for receiving the pure, stable-pressure compressed air output from the air pretreatment module and separating high-concentration nitrogen and high-concentration oxygen through the difference in gas permeation rates of different hollow fiber membranes; a mixing module for receiving the high-concentration nitrogen and high-concentration oxygen and uniformly mixing them according to a preset ratio to generate a nitrogen-oxygen mixed gas that meets training requirements; an exhalation resistance adjustment module for providing adjustable exhalation resistance for training, adapting to both normobaric and pressurized breathing training modes; an intelligent control module for collecting operating parameters of each module of the device and, through a precise control algorithm, coordinating the operating status of the air pretreatment module, hollow fiber membrane separation module, mixing module, and exhalation resistance adjustment module to match the gas concentration, flow rate, and pressure requirements of training; and a gas path system for connecting each functional module to form a pathway for gas source preparation, gas separation, mixing output, and exhalation regulation, ensuring stable gas transmission.

[0006] Preferably, the air pretreatment module includes a primary air filter, a variable frequency oil-free scroll air compressor, a cooler, a multi-stage impurity removal device, and a one-way valve A. The primary air filter removes fine particles and suspended matter from the air; the variable frequency oil-free scroll air compressor compresses the filtered air to a set pressure and stabilizes the output pressure through frequency conversion control; the cooler lowers the temperature of the compressed air, promoting the precipitation of water and oil mist molecules; the multi-stage impurity removal device removes droplets, oil, and ultrafine nanoparticles from the compressed air; and the one-way valve A prevents backflow of gas at the downstream end.

[0007] Preferably, the cooler uses a combination of air-cooled coil and semiconductor refrigeration module to cool the compressed air temperature to a preset range, and works with a temperature sensor for temperature control to ensure the compressed air pretreatment effect.

[0008] Preferably, the hollow fiber membrane separation module includes a hollow fiber nitrogen membrane, a hollow fiber oxygen membrane, an electro-proportional valve group, and a one-way valve group. The hollow fiber nitrogen membrane separates nitrogen from the air, outputting a high-concentration nitrogen flow; the hollow fiber oxygen membrane separates oxygen from the air, outputting a high-concentration oxygen flow; the electro-proportional valve group includes multiple electro-proportional valves installed on the inlet and outlet gas passages of the hollow fiber nitrogen and oxygen membranes, respectively used to regulate the inlet pressure and outlet pressure of the two hollow fiber membranes, establishing a pressure difference between the inside and outside of the membranes; the one-way valve group includes one-way valves B and C installed on the two high-concentration gas output pipelines to prevent gas backflow.

[0009] Preferably, the hollow fiber nitrogen membrane is used to discharge useless gas on the permeation side and to enrich the target gas on the retention side; the hollow fiber oxygen membrane is used to enrich the target gas on the permeation side and to discharge useless gas on the retention side.

[0010] Preferably, the gas mixing module includes a gas mass flow controller group, a mixing chamber, a concentration and pressure monitoring component, and a solenoid valve group. The gas mass flow controller group includes gas mass flow controllers A and B, respectively connected to the output ends of the hollow fiber nitrogen membrane and the hollow fiber oxygen membrane, for adjusting the output flow rates of high-concentration nitrogen and high-concentration oxygen. The mixing chamber is used for uniform mixing of the two gases. The concentration and pressure monitoring component includes an oxygen concentration sensor, a pressure sensor B, a safety valve A, and a pressure gauge B, for monitoring the oxygen concentration and pressure of the mixed gas. The solenoid valve group includes a first solenoid valve and a second solenoid valve, located on the output pipeline of the mixing chamber, for controlling the opening and closing of the mixed gas output path.

[0011] Preferably, the expiratory resistance adjustment module includes a pressure regulating valve, an electro-proportional valve E, a one-way valve D, a three-way valve, and safety protection components. The pressure regulating valve stabilizes the input pressure at a preset value, providing a base pressure for precise adjustment of downstream resistance. The electro-proportional valve E precisely controls expiratory resistance. The one-way valve D prevents backflow of gas in the airway. The three-way valve switches between normal pressure breathing and pressurized breathing pathways. The safety protection components include a safety valve B and a pressure gauge C, used to prevent excessively high expiratory pressure and monitor changes in expiratory pressure.

[0012] Preferably, the intelligent control module includes a PLC controller, a parameter acquisition unit, an optimization control unit, and an instruction execution unit, wherein the PLC controller serves as the main control unit; the parameter acquisition unit is used to acquire real-time operating data of the control device through pressure sensors, temperature sensors, oxygen concentration sensors, and a gas mass flow controller; the optimization control unit is used to calculate the optimal operating parameters of each actuator based on preset training parameters and acquired data using an algorithm; and the instruction execution unit is used to send control instructions to each actuator, including the frequency converter, driver, electro-proportional valve, gas mass flow controller, and solenoid valve.

[0013] Preferably, the optimization control unit supports reverse calculation of target parameters. Based on the preset oxygen concentration, total flow rate, and expiratory resistance of the mixed gas, it calculates the required inlet pressure, exhaust pressure, and adjustment parameters of gas mass flow controllers A and B for the hollow fiber membrane separation module, thereby achieving precise control. The oxygen concentration of the mixed gas is controlled within the range of 5% to 40%, the total flow rate is controlled within the range of 0 to 30 liters / minute, and the expiratory resistance is controlled within the range of 0 to 18 kPa.

[0014] Preferably, the air circuit system includes a constant pressure variable frequency air circuit, an air separation and mixing air circuit, and an exhalation resistance regulating air circuit. The constant pressure variable frequency air circuit connects in series with a primary air filter, a variable frequency oil-free scroll air compressor, a cooler, a multi-stage impurity removal device, and a one-way valve A to output pure, stable-pressure compressed air. The air separation and mixing air circuit connects to a hollow fiber nitrogen membrane and a hollow fiber oxygen membrane via branch structures, flows into the mixing chamber via a gas mass flow controller group, and finally connects to the breathing mask's air supply port. The exhalation resistance regulating air circuit connects in series with a pressure regulating valve, an electro-proportional valve E, a one-way valve D, and a three-way valve to the breathing mask's exhalation interface.

[0015] Therefore, this application has the following beneficial effects: This application embodiment utilizes an air pretreatment module based on variable frequency oil-free vortex compression and multi-stage filtration and cooling technology to directly use ambient air as the raw material gas source, eliminating dependence on bottled high-pressure oxygen and nitrogen, and improving the deployment capability and economic efficiency of the equipment in remote, high-altitude, and mobile scenarios. The hollow fiber membrane separation module employs parallel nitrogen and oxygen membranes, leveraging the physical differences in gas permeation rates within the membrane materials to achieve continuous and stable physical separation of nitrogen and oxygen in the air at ambient temperature and pressure, featuring low energy consumption, no pollution, compact structure, and reliable operation. The gas mixing module integrates a high-precision gas mass flow controller and a real-time oxygen concentration sensor, adjusting the mixing ratio of nitrogen and oxygen flow in real time according to training parameters, outputting a mixed gas with continuously adjustable oxygen concentration within the range of 5% to 40% and a precisely controllable total flow rate within the range of 0 to 30 liters / minute. The expiratory resistance adjustment module provides constant... The device features rapid switching between pressurized and compressed breathing modes, and precise setting of expiratory resistance within the 0-18 kPa range via the linkage control of an electric proportional valve and a three-way valve, effectively simulating respiratory load conditions in special working environments such as high altitudes and deep seas. Through an intelligent control module with a PLC at its core, it constructs a multi-parameter sensor network and closed-loop control loop encompassing pressure, temperature, flow rate, and concentration. Pre-set algorithms dynamically calculate and control the entire process of gas separation, mixing, and resistance adjustment in real time, ensuring that output parameters are highly consistent with the set targets, guaranteeing the safety and effectiveness of the training process. The highly integrated functional modules, based on optimized gas path and circuit design, form a clear and compact integrated device, reducing installation complexity and daily maintenance difficulty, improving overall reliability and user experience. This solves the problems of strong dependence on gas sources and the need for frequent replacement of bottled gas sources during training found in existing technologies.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of a hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to an embodiment of this application; Figure 2 This is a schematic diagram illustrating the operation of an intelligent control module according to an embodiment of this application; Figure 3 This is a diagram showing the operational connection of a gas circuit system according to an embodiment of this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The following description, with reference to the accompanying drawings, describes an embodiment of a hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to this application. Addressing the issue of strong gas source dependence mentioned in the background art, this application provides a hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device. In this method, an air pretreatment module directly uses ambient air as the raw material gas source based on variable frequency oil-free vortex compression and multi-stage filtration and cooling technology, eliminating dependence on bottled high-pressure oxygen and nitrogen, and improving the deployment capability and economic efficiency of the equipment in remote, high-altitude, and mobile scenarios. The hollow fiber membrane separation module employs parallel nitrogen and oxygen membranes, achieving continuous and stable physical separation of nitrogen and oxygen in the air at room temperature and pressure based on the physical differences in gas permeation rates within the membrane materials. This method features low energy consumption, no pollution, compact structure, and reliable operation. The mixing module integrates a high-precision gas mass flow controller and a real-time oxygen concentration sensor, adjusting the mixing ratio of nitrogen and oxygen flow in real time according to training parameters. The output oxygen concentration is continuously adjustable within the range of 5% to 40%, and the total flow rate is between 0 and 30 liters / km. The device provides precise and controllable mixed gas within minutes; it features a dual-mode rapid switching capability between normal and pressurized breathing through an expiratory resistance adjustment module, and precisely sets expiratory resistance within the range of 0 to 18 kPa using the linkage control of an electric proportional valve and a three-way valve, effectively simulating the respiratory load conditions of special working environments such as high altitude and deep sea; the intelligent control module, with a PLC as its core, constructs a multi-parameter sensor network and closed-loop control loop covering pressure, temperature, flow rate, and concentration, and uses preset algorithms to dynamically calculate and control the entire process of gas separation, mixing, and resistance adjustment in real time, ensuring that the output parameters are highly consistent with the set target, and guaranteeing the safety and effectiveness of the training process; through the high integration of various functional modules based on optimized gas path and circuit design, a clear structure and compact layout are formed into an integrated device, reducing installation complexity and daily maintenance difficulty, improving overall reliability and user experience, thereby solving the problems of strong dependence on gas source and frequent replacement of bottled gas sources during training in existing technologies.

[0020] Figure 1 This is a schematic diagram of the structure of a hollow fiber membrane nitrogen and oxygen gas separation and mixing intelligent control device provided in an embodiment of this application.

[0021] This application provides a hollow fiber membrane nitrogen and oxygen gas separation and mixing intelligent control device, such as... Figure 1 As shown, the device 10 includes: Air pretreatment module 100, hollow fiber membrane separation module 200, gas mixing module 300, expiratory resistance adjustment module 400, intelligent control module 500 and gas path system 600.

[0022] The system comprises the following modules: an air pretreatment module 100, a hollow fiber membrane separation module 200, and a gas mixing module 600. The air pretreatment module 100 filters, compresses, cools, and removes impurities from the external air, outputting pure, stable compressed air. The hollow fiber membrane separation module 200 receives the pure, stable compressed air from the air pretreatment module and separates high-concentration nitrogen and oxygen gas based on the differences in gas permeation rates of different hollow fiber membranes. The gas mixing module 300 receives the high-concentration nitrogen and oxygen gas and mixes them uniformly in a preset ratio to generate a nitrogen-oxygen mixture that meets training requirements. The expiratory resistance adjustment module 400 provides adjustable expiratory resistance for training, adapting to both normal and pressurized breathing modes. The intelligent control module 500 collects the operating parameters of each module and, through precise control algorithms, coordinates the operation of the air pretreatment module, hollow fiber membrane separation module, gas mixing module, and expiratory resistance adjustment module to match the required gas concentration, flow rate, and pressure for training. The gas path system 600 connects the various functional modules, forming a pathway for gas source preparation, gas separation, mixing output, and expiratory regulation, ensuring stable gas transmission.

[0023] It is understood that in this embodiment, the air pretreatment module serves as the core of the initial gas source treatment, using ambient air as raw material for purification and pressure stabilization, laying the foundation for gas separation. The hollow fiber membrane separation module, based on differences in gas permeation rates, simultaneously separates high-concentration nitrogen and oxygen from the pretreated air, achieving self-sufficiency and continuous production of the gas source. The gas mixing module, through high-precision flow control and real-time concentration feedback, dynamically mixes the two gases according to training needs, outputting a mixed gas with precisely adjustable concentration and flow rate. The expiratory resistance adjustment module provides settable resistance for breathing training, simulating respiratory load conditions in different working environments. The intelligent control module integrates multi-parameter sensing and closed-loop control algorithms to coordinate the operating status of each module, ensuring that the output gas parameters are consistent with the training target. The gas path system connects all the above modules, constructing a complete pathway from air treatment to gas delivery, ensuring stable gas flow and precise distribution within the system. Overall, it achieves on-site preparation, intelligent control, and stable supply of nitrogen-oxygen mixed gas for training, solving the problems of strong gas source dependence, frequent replacement of bottled gas sources during training, and insufficient system flexibility in existing technologies.

[0024] In this embodiment, the air pretreatment module 100 includes: a primary air filter 101, a variable frequency oil-free scroll air compressor 102, a cooler 103, a multi-stage impurity removal device 104, and a one-way valve A105.

[0025] The primary air filter 101 is used to filter out fine particles and suspended matter in the air; the variable frequency oil-free scroll air compressor 102 is used to compress the filtered air to a set pressure and stabilize the output pressure through frequency conversion control; the cooler 103 is used to reduce the temperature of the compressed air and promote the precipitation of water mist and oil mist molecules; the multi-stage impurity removal device 104 is used to remove droplets, oil stains and ultrafine nano-sized particles from the compressed air; and the one-way valve A105 is used to prevent backflow of gas at the downstream end.

[0026] It should be noted that the multi-stage impurity removal device specifically includes a vapor-liquid filter with an accuracy of 5 micrometers, an oil mist separator with an accuracy of 0.3 micrometers, and a precision filter with an accuracy of 0.01 micrometers, arranged sequentially along the airflow direction, thereby completing droplet discharge, oil mist separation, and ultrafine particle filtration in stages; the pressure stability of the compressed air is monitored in real time by a pressure sensor, and the signal is fed back to the intelligent control module, which dynamically adjusts the operating frequency of the variable frequency oil-free scroll air compressor to achieve this; at the same time, the operating status of the cooler is linked with the temperature sensor, and automatically starts and stops and adjusts the cooling power according to the monitored temperature value, thereby controlling the compressed air temperature within the set range.

[0027] It is understood that the embodiments of this application use a primary air filter as the initial purification unit to effectively intercept particulate matter in the ambient air and provide a clean air source for subsequent compression; use a variable frequency oil-free scroll air compressor as the core power and pressure building unit to continuously compress clean air to the required pressure, and rely on its variable frequency regulation characteristics to maintain a high degree of stability in the output pressure, creating stable operating conditions for membrane separation; use a cooler as a temperature control and media precipitation unit to actively reduce the temperature of compressed air, causing water vapor and any trace amounts of oil vapor to condense, creating conditions for deep impurity removal; use a multi-stage impurity removal device as a deep purification unit, in which a vapor-liquid filter, an oil mist separator, and a precision filter sequentially perform graded treatment on the cooled compressed air to thoroughly remove liquid water droplets, oil mist, and ultrafine particles, ensuring that the purity of the air source meets the stringent requirements of the hollow fiber membrane; and use a one-way valve as a fluid guidance protection unit to prevent downstream gas or pressure fluctuations from adversely interfering with the stable operating state of the upstream stage. The above-mentioned components are connected in sequence and function in a coordinated manner to form a complete and efficient air pretreatment process. Their synergistic effect not only directly utilizes the inexhaustible air as raw material, but also fundamentally ensures the comprehensive quality of the output compressed air in terms of pressure, cleanliness and dryness. This lays a reliable foundation for subsequent gas separation and precise control, thereby systematically solving the problem of traditional solutions' strong dependence on bottled gas sources.

[0028] For example, after the hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device is activated, the ambient air first passes through a pre-filter to remove dust and suspended particulate matter with a diameter greater than 10 micrometers. Then, the filtered air enters a variable frequency oil-free scroll air compressor, where it is compressed to a set pressure of 0.7 MPa. A pressure sensor monitors the pipeline pressure in real time and feeds the signal back to the intelligent control module, which dynamically adjusts the compressor's operating frequency to stably control the output pressure between 0.69 and 0.71 MPa. The high-temperature compressed air then enters a cooler, where the temperature drops from approximately 80 degrees Celsius to 25 degrees Celsius under the action of the air-cooled coil and semiconductor refrigeration module, causing water vapor and oil mist to condense. Afterward, the airflow passes through a multi-stage impurity removal device: first, a 5-micron vapor-liquid filter separates and automatically discharges condensate droplets; then, a 0.3-micron oil mist separator captures fine oil mist; and finally, a 0.01-micron precision filter removes ultrafine particles. The treated, clean, dried, and pressure-stabilized compressed air ultimately flows through one-way valve A, ensuring unidirectional delivery to the subsequent separation module and effectively preventing gas backflow from interfering with the upstream operation. The entire pretreatment process operates continuously under fully automated control, providing a stable and qualified gas source for membrane separation.

[0029] In this embodiment, the cooler uses a combination of air-cooled coil and semiconductor refrigeration module to cool the compressed air temperature to a preset range, and works with a temperature sensor for temperature control to ensure the compressed air pretreatment effect.

[0030] It is understood that in this embodiment, the cooler, as the core of compressed air temperature control and condensation pretreatment, adopts a composite cooling method combining air-cooled coils and semiconductor refrigeration modules. This enables efficient and rapid cooling of high-temperature compressed air to a preset low-temperature range. Together with a temperature sensor, it forms a closed-loop temperature control system, achieving precise monitoring and automatic adjustment of the outlet air temperature. This not only improves the cooling efficiency and stability of the compressed air but also effectively promotes the condensation and precipitation of water vapor and oil mist in the air, creating the necessary conditions for the efficient separation of liquid impurities by subsequent multi-stage impurity removal devices. This ensures the overall dryness and purity of the pretreated compressed air.

[0031] In this embodiment, the hollow fiber membrane separation module 200 includes a hollow fiber nitrogen membrane 201, a hollow fiber oxygen membrane 202, an electro-proportional valve group 203, and a one-way valve group 204.

[0032] The hollow fiber nitrogen membrane 201 is used to separate nitrogen from the air and output a high-concentration nitrogen flow; the hollow fiber oxygen membrane 202 is used to separate oxygen from the air and output a high-concentration oxygen flow; the electro-proportional valve group 203 includes multiple electro-proportional valves installed on the inlet and outlet passages of the hollow fiber nitrogen membrane and the hollow fiber oxygen membrane, which are used to regulate the inlet pressure and outlet pressure of the two hollow fiber membranes respectively, and establish a pressure difference between the inside and outside of the membrane; the one-way valve group 204 includes one-way valves B and C installed on the two high-concentration gas output pipelines to prevent gas backflow.

[0033] It should be noted that the electro-proportional valve assembly specifically includes electro-proportional valves A and C, located on the pure compressed air input main line, which are used to independently and precisely regulate the inlet pressure to the hollow fiber nitrogen membrane and hollow fiber oxygen membrane, respectively. It also includes electro-proportional valves B and D, connected to the exhaust ports of the two membranes, which establish and stabilize the pressure difference between the permeate and stagnation sides of their respective membrane modules by regulating their outlet back pressure. This pressure difference is a key parameter driving gas separation and determining the output gas concentration and flow rate. The separation process of the hollow fiber nitrogen membrane and hollow fiber oxygen membrane follows their respective specific gas separation operating characteristic curves. Based on the target output gas concentration and flow rate parameters, the intelligent control module obtains the optimal operating parameters for each membrane, such as the inlet pressure and exhaust port back pressure, through inverse calculation, and instructs the electro-proportional valve assembly to coordinate its actions to achieve precise control.

[0034] It is understood that this embodiment uses hollow fiber nitrogen membrane and hollow fiber oxygen membrane as parallel gas physical separation cores. Based on the inherent difference in the permeation rate of oxygen and nitrogen molecules in specific membrane materials, high-concentration nitrogen and oxygen are directly and continuously separated from pretreated air at room temperature, achieving self-sufficiency and efficient conversion of gas source. An electro-proportional valve group serves as the dynamic pressure control hub for the membrane separation process, independently and in a closed-loop precise adjustment of the inlet pressure and exhaust back pressure of the two membranes, thereby establishing and maintaining the optimal operating pressure difference that conforms to the membrane separation characteristic curve, ensuring stable gas separation efficiency and output quality. A one-way valve group serves as the flow direction guarantee unit for the output gas, effectively preventing mixed gas or downstream pressure fluctuations from back-end intruding into the membrane module, protecting the cleanliness and separation performance of the separation membrane. The synergy of the above components and intelligent algorithms constitutes an efficient and controllable gas preparation unit, providing a high-purity nitrogen and oxygen source with precisely set concentrations and flow rates for subsequent proportional mixing. This is a core technological link in achieving intelligent gas mixing and eliminating dependence on bottled gas.

[0035] For example, when the device needs to prepare a mixed gas of a specific concentration, the intelligent control module calculates the required flow rates of the high-concentration nitrogen stream (approximately 5% oxygen and 95% nitrogen) and the high-concentration oxygen stream (approximately 40% oxygen) based on preset targets (e.g., total flow rate of 20 liters / minute and oxygen concentration of 18%). Subsequently, it controls electro-proportional valves A and C to stabilize the inlet pressure to both membranes at 0.6 MPa; simultaneously, it adjusts electro-proportional valves B and D to control the back pressure at the exhaust ports of the hollow fiber nitrogen membrane and the hollow fiber oxygen membrane at 0.1 MPa, thus establishing suitable separation driving forces for each. Under this operating condition, the hollow fiber nitrogen membrane outputs high-concentration nitrogen from its stagnation side, and the hollow fiber oxygen membrane outputs high-concentration oxygen from its permeation side. The two streams are led out through check valves B and C respectively, and their flow rates are precisely controlled by the downstream mass flow controller receiving instructions. The entire separation process is continuous and automatic, providing a stable and reliable gas source for the gas mixing module.

[0036] In the embodiments of this application, the permeation side of the hollow fiber nitrogen membrane is used to discharge useless gas, and the retention side is used to enrich the target gas; the permeation side of the hollow fiber oxygen membrane is used to enrich the target gas, and the retention side is used to discharge useless gas.

[0037] It is understood that the embodiments of this application clearly define the physical path and gas flow direction of the membrane separation process by explicitly defining the functions of the permeate side and retention side of the hollow fiber nitrogen membrane and the hollow fiber oxygen membrane. Specifically, for the hollow fiber nitrogen membrane, its permeate side serves as a selective channel and enrichment outlet for specific gas molecules, allowing gas components in the air that can quickly permeate the membrane material to be guided and discharged on this side, thereby effectively removing them from the mainstream. Its retention side, on the other hand, serves as a convergence and output channel for the target gas components, allowing gas components blocked by the membrane material or with slow permeation rates to continuously accumulate on this side, forming a high-concentration gas flow output. For the hollow fiber oxygen membrane, its permeate side is used to enrich the target gas, serving as a convergence and output channel for high-concentration target gas components. Gas components in the air blocked by the membrane material or with slow permeation rates are retained on this side. The pressure difference established by the electro-proportional valve controls the discharge of useless gas from the retention side through a controllable and adjustable pressure difference, effectively removing it from the mainstream. This physical separation mechanism, based on the difference in permeability selectivity of membrane materials, achieves efficient and continuous separation of nitrogen and oxygen in the air at room temperature and pressure without the need for chemical reactions or phase transitions. Not only is the separation process stable and reliable with low energy consumption, but it also ensures the purity of the separated products and the controllability of the separation efficiency from a physical perspective, providing a pure and stable single gas source for subsequent precise gas mixing.

[0038] In this embodiment, the gas mixing module 300 includes a gas mass flow controller group 301, a gas mixing chamber 302, a concentration and pressure monitoring component 303, and a solenoid valve group 304.

[0039] The gas mass flow controller group 301 includes gas mass flow controllers A and B, which are respectively connected to the output ends of the hollow fiber nitrogen membrane and the hollow fiber oxygen membrane, and are used to regulate the output flow rates of high-concentration nitrogen and high-concentration oxygen; the mixing chamber 302 is used to uniformly mix the two gases; the concentration and pressure monitoring component 303 includes an oxygen concentration sensor, a pressure sensor B, a safety valve A, and a pressure gauge B, and is used to monitor the oxygen concentration and pressure of the mixed gas; the solenoid valve group 304 includes a first solenoid valve and a second solenoid valve, which are installed on the output pipeline of the mixing chamber and are used to control the opening and closing of the mixed gas output path.

[0040] It should be noted that the determination of the mixing ratio is based on the principle of conservation of mass. Let the oxygen concentration of the target mixed gas be... Total flow is The oxygen concentration of the oxygen-enriched flow from the hollow fiber oxygen membrane is The oxygen concentration of the nitrogen-rich gas stream from the hollow fiber nitrogen membrane is The required flow rates of the two airflows are then determined by the following formula: Oxygen-enriched flow rate:

[0041] Nitrogen-enriched airflow rate:

[0042] The intelligent control module is based on user settings. and and the corresponding operating parameters of the membrane module and The above formula is used to calculate in real time, and the target flow values ​​for gas mass flow controllers A and B are set. Solenoid valve A is located on the gas supply line from the mixed gas output to the breathing mask and is open during training. Solenoid valve B is located on another output path of the mixing chamber, and its on / off logic is the reverse of solenoid valve A. It is opened during the gas preparation and pre-adjustment stage to establish a circulation path and stabilize gas parameters. Monitoring data from the oxygen concentration sensor is fed back to the intelligent control module in real time. When the oxygen concentration of the mixed gas deviates from the set value, the control module will fine-tune the flow settings of the two airflows according to the above formula, forming a closed-loop control to ensure highly accurate and stable output gas concentration.

[0043] It is understood that the embodiments of this application, through the combination of the above-mentioned theoretical formulas and a high-precision gas mass flow controller, achieve a digital and precise integration of the mixing ratio from theoretical calculation to physical execution; the mixing chamber serves as a homogenization unit to ensure thorough mixing of gas molecules; a real-time mass control unit is constructed using an oxygen concentration sensor and a closed-loop correction algorithm; and a safe and reliable switching between "preparation and debugging" and "training gas supply" states is achieved through the interlocking logic design of dual solenoid valves. The synergy of these components and algorithms enables the device to dynamically and precisely prepare a mixed gas with an continuously adjustable oxygen concentration within the range of 5% to 40% and a precisely controllable total flow rate between 0 and 30 liters per minute, according to training requirements, and to achieve instantaneous response for training start and stop.

[0044] For example, when preparing a mixed gas with an oxygen concentration of 21% and a total flow rate of 15 liters / minute, the intelligent control module automatically calculates and sets the flow rates of gas mass flow controllers A and B to approximately 12.18 liters / minute and approximately 2.82 liters / minute, respectively, based on preset target parameters and the system's known membrane separation gas concentration. Subsequently, the two gas streams mix in the mixing chamber, with the oxygen concentration sensor monitoring in real time. If the reading is 20.8%, the control module automatically fine-tunes the flow rate settings based on the deviation until the reading stabilizes at 21.0%. Before training begins, solenoid valve A is closed and solenoid valve B is open, allowing the mixed gas to circulate within the device to stabilize parameters. After the training command is issued, solenoid valve B closes, and solenoid valve A opens instantaneously, delivering the calibrated mixed gas to the breathing mask.

[0045] In this embodiment, the expiratory resistance adjustment module 400 includes a pressure regulating valve 401, an electro-proportional valve E402, a one-way valve D403, a three-way valve 404, and a safety protection component 405.

[0046] The pressure regulating valve 401 is used to stabilize the input pressure at a preset value, providing a base pressure for precise adjustment of the downstream resistance; the electro-proportional valve E402 is used to precisely control the expiratory resistance; the one-way valve D403 is used to prevent gas backflow in the airway; the three-way valve 404 is used to switch the airway channels between normal pressure breathing and pressurized breathing; the safety protection component 405 includes a safety valve B and a pressure gauge C, which are used to prevent excessive pressure on the expiratory side and to monitor changes in expiratory pressure.

[0047] It should be noted that the three-way valve is an electrically controlled switching valve with two operating positions: In normobaric hypoxic training mode, it connects the exhalation port of the breathing mask directly to the atmospheric environment, where the expiratory resistance is approximately atmospheric pressure; in pressurized breathing training mode, it switches the exhalation port to the airway connected to the electro-proportional valve E, which establishes and maintains a back pressure higher than atmospheric pressure. This back pressure is the expiratory resistance required for training. The electro-proportional valve E is a pressure relief type proportional valve, and the intelligent control module can accurately and stably maintain this pressure by setting its outlet pressure value.

[0048] It is understood that this embodiment of the application, through the cascaded design of the pressure regulating valve and the electro-proportional valve E, achieves stepless and high-precision setting of expiratory resistance within the range of 0-18 kPa. The pressure regulating valve provides a stable air source for coarse adjustment, while the electro-proportional valve E enables fine adjustment and closed-loop maintenance. An electrically controlled three-way valve serves as the mode switching hub, enabling rapid and reliable conversion between normobaric and pressurized breathing training modes, simplifying the operation process. A one-way valve ensures the unidirectionality of the resistance adjustment air path, and a safety valve provides intrinsic safety protection. This module allows a single device to flexibly simulate different respiratory load conditions, from high-altitude normobaric hypoxic environments to high-altitude rapid pressurization environments, greatly enhancing the relevance of training and the versatility of the equipment.

[0049] For example, during normobaric hypoxia training, the three-way valve is in the normally open atmospheric position, allowing the user to exhale directly into the atmosphere without additional resistance. When switching to pressurized breathing training and setting the expiratory resistance to 12 kPa, the three-way valve activates, connecting the expiratory pathway to the electro-proportional valve E circuit. The intelligent control module sends a control signal corresponding to 12 kPa to the electro-proportional valve E, while the pressure sensor downstream of pressure gauge C monitors the actual pressure. When the user exhales, they must overcome the back pressure set by this valve, thus creating resistance. If changes in expiratory flow cause fluctuations in the monitored pressure, the control module will dynamically adjust the opening of the electro-proportional valve E to quickly return the pressure to the 12 kPa set value, maintaining stable resistance.

[0050] In this embodiment, the intelligent control module 500 includes a PLC controller 501, a parameter acquisition unit 502, an optimization control unit 503, and an instruction execution unit 504.

[0051] Among them, the PLC controller 501 serves as the main control unit; the parameter acquisition unit 502 is used to acquire real-time operating data of the control device through pressure sensors, temperature sensors, oxygen concentration sensors, and gas mass flow controllers; the optimization control unit 503 is used to calculate the optimal operating parameters of each actuator through an algorithm based on preset training parameters and acquired data; and the instruction execution unit 504 is used to send control instructions to each actuator, including the frequency converter, driver, electric proportional valve, gas mass flow controller, and solenoid valve.

[0052] It should be noted that the core algorithms of the optimized control unit include: a variable frequency constant pressure control algorithm, which uses feedback from a pressure sensor to adjust the output frequency of the frequency converter via PID control, thereby controlling the speed of the oil-free scroll air compressor and achieving high-precision stability of compressed air pressure; a membrane separation calculation and control algorithm, which, based on the user-set target total flow rate and oxygen concentration of the mixed gas, and combined with the known separation characteristic curves of the hollow fiber nitrogen membrane and oxygen membrane, calculates inversely the required inlet pressure setpoint, exhaust back pressure setpoint, and target nitrogen / oxygen flow rate for each membrane, and achieves this by adjusting the corresponding electro-proportional valves; and a mixed gas closed-loop correction algorithm, which, based on feedback from the oxygen concentration sensor, compares the result with the target concentration and dynamically fine-tunes the setpoint of the gas mass flow controller to eliminate deviations.

[0053] It is understood that this application embodiment constructs an intelligent neural network covering the entire process of gas source processing, membrane separation, gas mixing, and breathing resistance simulation through a distributed measurement and control architecture centered on a PLC. The parameter acquisition unit senses subtle changes in every aspect of the device in real time; the optimization control unit uses preset algorithms and characteristic curves for rapid calculation and decision-making; and the instruction execution unit precisely drives the actions of each actuator. This fully closed-loop intelligent collaborative control not only achieves a high degree of automation from one-click setting of training parameters to automatic output of qualified gas, but also ensures the long-term stability and repeatability of output gas concentration, flow rate, and breathing resistance under different operating conditions. It fundamentally upgrades traditional equipment that relies on manual experience for operation and adjustment into precise, reliable, and easy-to-use intelligent training equipment.

[0054] For example, such as Figure 2As shown, the user clicks the start control on the touchscreen, sets the training mode to "pressurized low oxygen," with a target oxygen concentration of 18%, a total flow rate of 20 liters / minute, and an expiratory resistance of 10 kPa. Upon receiving the instructions and parameters, the PLC controller (in this embodiment, a Siemens S7-200SMART is used) immediately activates its optimization control unit. First, it acquires data from pressure sensor A and temperature sensor through the parameter acquisition unit and runs the variable frequency constant pressure control algorithm: the PLC sends operating parameters to the inverter to drive the oil-free scroll air compressor (such as the Gallop G03ZP model). As the pressure rises, when the temperature reaches the preset value of 25 degrees Celsius, the PLC instructs the driver to activate the cooler (a combination of air-cooled coil and semiconductor refrigeration module) for cooling. The PLC continuously collects pressure data through pressure sensor A and continuously calculates and adjusts the frequency parameters sent to the inverter, gradually approaching and ultimately stabilizing the compressed air pressure at the preset value of 0.7 MPa. After the compressed air pressure stabilizes, the membrane separation calculation algorithm is activated. Based on the target oxygen concentration of 18% and the total flow rate of 20 liters / minute, and combined with the stored membrane characteristic curves, it calculates inversely that the outlet pressures of electro-proportional valves A and C need to be controlled at 0.6 MPa, and the back pressures of electro-proportional valves B and D need to be controlled at 0.15 MPa and 0.05 MPa respectively. The target flow rates for gas mass flow controllers A and B are also preset. The command execution unit then drives the corresponding electro-proportional valves, solenoid valve B, and three-way valve to establish gas separation and circulation pathways. During the gas mixing stage, feedback data from the oxygen concentration sensor is continuously collected, and the gas mixing closed-loop correction algorithm performs dynamic fine-tuning. Simultaneously, the expiratory resistance adjustment algorithm sets the output pressure of electro-proportional valve E based on the target of 10 kPa and controls the three-way valve to switch to the pressurization circuit. The entire startup, calculation, and control process is completed automatically within tens of seconds, and the touchscreen displays "Gas preparation ready." Once the training start command is issued, the system enters a stable training gas supply state.

[0055] In this embodiment, the optimization control unit supports reverse calculation of target parameters. Based on the preset oxygen concentration, total flow rate, and expiratory resistance of the mixed gas, it calculates the required inlet pressure, exhaust flow rate, and adjustment parameters of gas mass flow controllers A and B for the hollow fiber membrane separation module, thereby achieving precise control. The oxygen concentration of the mixed gas is controlled within the range of 5% to 40%, the total flow rate is controlled within the range of 0 to 30 liters / minute, and the expiratory resistance is controlled within the range of 0 to 18 kPa.

[0056] It is understood that this application embodiment constructs an intelligent calculation bridge from user settings to system execution by optimizing the reverse calculation capability of the control unit's target parameters. This function enables the system to automatically and backward calculate the precise control parameters that each front-end execution link must achieve based on the final required training gas parameters, such as the inlet pressure required by the membrane module, the back pressure of the exhaust port, and the preset values ​​of the two gas mass flow controllers. This "end-oriented" reverse calculation control strategy transforms the complex, coupled multivariate regulation problem into a deterministic calculation problem based on known mathematical models and membrane characteristic curves. This allows the entire device to directly respond to changing training needs through the rapid calculation of the PLC, completing the coordinated parameter setting of multiple actuators at once. This fundamentally avoids the traditional extensive control method that relies on trial and error based on manual experience, achieving fully automatic, high-precision, and rapid response from the training target to gas supply. It is the core control logic for the device to achieve intelligence and precision.

[0057] In this embodiment, the gas path system 600 includes: a constant pressure variable frequency gas path 601, an air separation and mixing gas path 602, and an exhalation resistance regulating gas path 603.

[0058] The constant pressure variable frequency air circuit 601 is connected in series with a primary air filter, a variable frequency oil-free scroll air compressor, a cooler, a multi-stage impurity removal device, and a one-way valve A to output pure and stable compressed air; the air separation and mixing air circuit 602 is connected to a hollow fiber nitrogen membrane and a hollow fiber oxygen membrane through a branch structure, and then enters the mixing chamber through a gas mass flow controller group, and finally connects to the air supply port of the breathing mask; the exhalation resistance regulating air circuit 603 is connected in series with a pressure regulating valve, an electro-proportional valve E, a one-way valve D, and a three-way valve to the exhalation interface of the breathing mask.

[0059] It should be noted that the constant pressure variable frequency air supply circuit consists of a primary air filter, a variable frequency oil-free scroll air compressor, a cooler, a multi-stage impurity removal device, and a one-way valve A connected in series, forming the main supply line from air intake to pure, stable-pressure compressed air output. The air separation and mixing circuit starts at the branch point after one-way valve A, splitting into two branches that pass through electro-proportional valves A and C to the hollow fiber nitrogen membrane and hollow fiber oxygen membrane, respectively. The gases separated from the two membranes are led out through one-way valves B and C, and then pass through gas mass flow controllers A and B, respectively, before converging in the mixing chamber. After passing through a monitoring section consisting of an oxygen concentration sensor and pressure sensor B, the gas is finally controlled by solenoid valve A to be supplied to the breathing mask air inlet. The expiratory resistance regulating air supply circuit also starts at the branch point after one-way valve A, and is connected in sequence to a pressure regulating valve, electro-proportional valve E, one-way valve D, and a three-way valve, finally connecting to the breathing mask exhalation port.

[0060] In the air separation and mixing circuit, electro-proportional valves B and D are connected to the exhaust outlets of the hollow fiber nitrogen membrane and oxygen membrane, respectively, to regulate the separation pressure difference. The exhaust gas from these outlets is directly discharged into the atmosphere. Additionally, a branch of solenoid valve B is connected in parallel between the mixing chamber outlet and solenoid valve A. This branch is closed during training and opened during pre-preparation, forming an internal circulation calibration path with the upstream components. The three-way valve in the expiratory resistance adjustment circuit has one end open to the atmosphere, another end connected to the expiratory port, and the third end connected to the pressurization adjustment circuit. The expiratory path is changed by switching its position.

[0061] It is understood that the embodiments of this application, through the organic integration of three logically clear and functionally defined gas path subsystems, constitute a vascular network for the device's material transport. The constant-pressure variable-frequency gas path, acting as an artery, is responsible for generating and delivering high-quality, pure compressed air; the air separation and mixing gas path, as the core metabolic and distribution system, uses membrane modules to separate and purify air into nitrogen and oxygen components, then precisely mixes them into a mixed gas of a specific concentration as needed; and the expiratory resistance regulation gas path, as a dynamic pressure regulation system, provides a settable reverse load for the exhalation process. These three gas paths are not isolated but share a gas source through the connection of one-way valves and diversion points, and achieve coordinated management of pressure, flow, and on / off states through an intelligent control module. This integrated gas path design allows complex gas preparation, mixing, and resistance simulation functions to be implemented efficiently and reliably within a compact space, and the pipeline routing is intuitive, greatly facilitating installation, commissioning, and troubleshooting.

[0062] For example, such as Figure 3As shown, after the device is started, the outside air first passes through a 10-micron primary air filter (1) to remove dust and impurities, and then is drawn in and compressed through the inlet of the oil-free scroll air compressor (2). After passing through pressure gauge A (3) and pressure sensor A (4), the compressed air enters the cooler (5) to cool down, and the temperature is monitored by temperature sensor (6). The cooled compressed air flows through a 5-micron vapor-liquid filter (7), a 0.3-micron oil mist separator (8), and a 0.01-micron precision filter (9) in sequence to remove droplets, oil mist, and ultrafine particles, resulting in pure compressed air. After passing through one-way valve A (10), the gas flow is divided into three. The main path enters the air separation mixed gas path: one path is sent to the inlet of the hollow fiber nitrogen membrane (21) after being stabilized by the electric proportional valve A (11), and its exhaust port is controlled by the back pressure of the electric proportional valve B (12); the separated high-concentration nitrogen is output through one-way valve B (23) and gas mass flow controller A (26). Another path is fed into the inlet of the hollow fiber oxygen membrane (22) after being stabilized by the electro-proportional valve C (13), and its exhaust port is controlled by the back pressure of the electro-proportional valve D (14); the separated high-concentration oxygen is output through the one-way valve C (24) and the gas mass flow controller B (27). The two airflows are mixed in the mixing chamber (29), and the mixed gas flows through the oxygen concentration sensor (30), the pressure sensor B (31), the safety valve A (32), and the pressure gauge B (33). During the preparation stage, the solenoid valve A (34) is closed and the solenoid valve B (38) is open, and the gas circulates internally; during training, the solenoid valve B (38) is closed and the solenoid valve A (34) is open, and the gas is delivered to the mask. The third path is the expiratory resistance regulating airway: the airflow is reduced to 0.19 MPa by the pressure regulating valve (28), and then through the electro-proportional valve E (15) and the one-way valve D (25), and controlled by the three-way valve (35). During pressurized breathing training, the three-way valve switches, allowing the expiratory airflow to flow through the electro-proportional valve E to establish back pressure (e.g., 10 kPa), and then connects to the mask's exhalation port via the safety valve B (36) and pressure gauge C (37). All airway components work in coordination with the intelligent control module, ultimately achieving a stable preparation and supply of the entire process from air to the training gas mixture.

[0063] This application proposes a hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device. Through an air pretreatment module based on variable frequency oil-free vortex compression and multi-stage filtration cooling technology, it directly uses ambient air as the raw material gas source, eliminating dependence on bottled high-pressure oxygen and nitrogen, and improving the deployment capability and economic efficiency of the equipment in remote, high-altitude, and mobile scenarios. The hollow fiber membrane separation module uses parallel nitrogen and oxygen membranes, achieving continuous and stable physical separation of nitrogen and oxygen in the air at room temperature and pressure based on the physical differences in gas permeation rates within the membrane materials. This results in low energy consumption, no pollution, compact structure, and reliable operation. The mixing module integrates a high-precision gas mass flow controller and a real-time oxygen concentration sensor, adjusting the mixing ratio of nitrogen and oxygen flow in real time according to training parameters, outputting a mixed gas with continuously adjustable oxygen concentration within the range of 5% to 40% and a precisely controllable total flow rate within the range of 0 to 30 liters / minute. The expiratory resistance adjustment module enables rapid switching between normal pressure and pressurized breathing modes. Through the coordinated control of an electric proportional valve and a three-way valve, the expiratory resistance can be precisely set within the range of 0 to 18 kPa, effectively simulating the respiratory load conditions of special working environments such as high altitudes and deep seas. The intelligent control module, centered on a PLC, constructs a multi-parameter sensor network and closed-loop control loop encompassing pressure, temperature, flow rate, and concentration. Pre-set algorithms dynamically calculate and control the entire process of gas separation, mixing, and resistance adjustment in real time, ensuring that output parameters are highly consistent with the set targets, guaranteeing the safety and effectiveness of the training process. The highly integrated functional modules, based on optimized gas path and circuit design, form a clear and compact integrated device, reducing installation complexity and daily maintenance difficulty, improving overall reliability and user experience. This solves the problems of strong dependence on gas sources and the need for frequent replacement of bottled gas sources during training found in existing technologies.

[0064] The following will describe a hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device through a specific embodiment, including: The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device is started. The operator sets detailed parameters for this simulation training via its integrated touchscreen human-machine interface: the training mode is selected as "pressurized low oxygen"; the oxygen concentration of the target mixed gas is set to 18%; the total gas supply flow rate is set to 20 liters per minute; and the expiratory resistance is set to 10 kPa. These parameters are sent to the PLC controller, the core control unit of the system, via the touchscreen's communication interface.

[0065] Upon receiving the command, the PLC controller activates its internal optimized control unit program. The program first establishes a qualified air source. The controller, through the parameter acquisition unit, reads data from the pressure and temperature sensors installed on the outlet pipeline of the oil-free scroll air compressor. At this point, the pressure in the system's air circuit is lower than the preset value. The PLC sends a command to the frequency converter, driving the variable frequency oil-free scroll air compressor to start operation. Ambient air is drawn into the intake device and passes through a 10-micron precision pre-filter, removing most suspended particles such as dust and pollen larger than 10 microns in diameter. The pre-purified air enters the compression chamber of the oil-free scroll air compressor for compression, causing a rapid increase in pressure and temperature. When the temperature sensor detects that the compressed air temperature has reached the preset safety threshold of 25 degrees Celsius, the PLC sends a start command to the cooler's driver. The cooler employs a composite cooling scheme combining air-cooled coils and semiconductor refrigeration modules to cool the high-temperature airflow. This cooling process causes water vapor and any trace amounts of oil vapor in the compressed air to condense into tiny droplets. The airflow then passes through a multi-stage impurity removal system: first, it passes through a 5-micron precision vapor-liquid filter with automatic drainage to separate and discharge condensate droplets; second, it passes through a 0.3-micron precision oil mist separator to capture and separate extremely fine oil mist; finally, it passes through a 0.01-micron precision filter to remove ultrafine particles and microorganisms, ensuring the purity of the output compressed air. Throughout the entire air source setup process, pressure sensors continuously feed back the real-time pressure value in the pipeline to the PLC. The PLC's internal variable frequency constant pressure control algorithm calculates the deviation between this feedback value and the 0.7 MPa setpoint and converts the result into a frequency adjustment command, which is sent to the frequency converter in real time. The frequency converter then precisely adjusts the speed of the oil-free scroll air compressor motor, and through dynamic and continuous closed-loop regulation, stabilizes the output pressure of the compressed air between 0.69 and 0.71 MPa. At this point, a stable, dry, and clean stream of compressed air is generated through one-way valve A.

[0066] Clean compressed air flows through one-way valve A and is divided into three branches. The main branch enters the core process of air separation and mixing. The main airflow is first split, directed to two parallel electro-proportional valves A and C. These two electro-proportional valves receive commands from the PLC to precisely regulate and stably output the inlet airflow pressure at 0.6 MPa. One stream flows to the inlet of the hollow fiber nitrogen membrane module, and the other to the inlet of the hollow fiber oxygen membrane module. The physical process of membrane separation then unfolds. For the hollow fiber nitrogen membrane, when clean air at a pressure of 0.6 MPa flows through the membrane module, due to the difference in the permeation rates of oxygen and nitrogen in the membrane material, oxygen can quickly permeate through the membrane wall into the permeate side, while nitrogen is largely blocked on the retention side. Electro-proportional valve B, connected to the permeate side outlet of the membrane, receives commands from the PLC and sets and maintains its outlet back pressure at 0.15 MPa, thereby creating a specific pressure differential driving force across the membrane. Ultimately, on the stagnation side of the nitrogen membrane, the nitrogen concentration is enriched to a high level, forming a "nitrogen-rich gas flow." This gas flow passes through one-way valve B and enters gas mass flow controller A. A similar process occurs simultaneously in the hollow fiber oxygen membrane module. The PLC controls the electro-proportional valve D connected to the stagnation side of the oxygen membrane to stabilize its stagnation back pressure at 0.05 MPa. Under these conditions, oxygen is enriched on the permeation side of the membrane, forming an "oxygen-rich gas flow." This gas flow passes through one-way valve C and enters gas mass flow controller B. Unused waste gases from both membrane modules are discharged from the system in an orderly manner under the control of electro-proportional valves B and D.

[0067] At the initial input of training parameters, the PLC's optimization control unit automatically calculates the theoretical flow rates of the required oxygen-enriched and nitrogen-enriched gas streams based on the preset target mixed gas oxygen concentration of 18% and total flow rate of 20 liters / minute, combined with the known output gas concentration parameters of the membrane module. The PLC sends these two flow rate setpoints to gas mass flow controllers B and A, respectively. The mass flow controllers, with high precision and rapid response, adjust the gas flow from the membrane module to the set flow rates. The two gas streams are then fed into the mixing chamber, whose design ensures thorough and uniform mixing. The mixed gas flows through a real-time online monitoring oxygen concentration sensor and a pressure sensor. The oxygen concentration sensor transmits the measured oxygen percentage reading back to the PLC in real time. The PLC's closed-loop correction algorithm continuously compares this reading with the target value of 18%. Once a deviation is detected, the algorithm immediately calculates the fine-tuning amount for the setpoints of the two mass flow controllers and executes the correction. Through rapid iterative feedback, the oxygen concentration of the mixed gas is precisely stabilized at the target value of 18.0%. During the preparation phase before training begins, solenoid valve A on the main output line of the mixing chamber is closed, while solenoid valve B on the bypass line remains open. This allows the mixed gas to continuously circulate within the device, ensuring complete parameter stabilization and pre-filling the breathing mask and connecting lines with qualified gas. The touchscreen displays "Gas preparation ready."

[0068] Another air path branching off from one-way valve A enters the expiratory resistance regulation system. This airflow first passes through a mechanical pressure regulating valve, stabilizing the pressure from 0.7 MPa to 0.19 MPa, providing the base air source for subsequent regulation. This low-pressure airflow then enters the electro-proportional valve E. During the training preparation phase, the PLC has sent a corresponding control signal to the electro-proportional valve E based on the resistance setpoint of 10 kPa, causing it to enter the preset state. The three-way valve connected to the breathing mask's expiratory interface circuit is in the "normal pressure" position during the preparation phase, allowing the exhalation port to be directly connected to the atmosphere.

[0069] Once the operator confirms readiness and issues the training start command, the PLC sends a series of coordinated commands to the execution unit. Solenoid valve B in the gas mixing module closes, cutting off the internal circulation path; solenoid valve A opens instantaneously, delivering the prepared, stable gas mixture to the breathing mask. Simultaneously, the three-way valve in the expiratory resistance adjustment module activates, switching from the "normal pressure" position to the "pressurized" position, connecting the trainee's expiratory outlet passage to the pressurized circuit controlled by the electro-proportional valve E. When the trainee exhales, they must overcome the 10 kPa back pressure maintained by the electro-proportional valve E, creating expiratory resistance. A pressure sensor installed in the expiratory circuit feeds back the actual pressure value to the PLC, which dynamically adjusts the electro-proportional valve E through closed-loop control to ensure the expiratory resistance remains stable at 10 kPa.

[0070] Thus, the device has established a complete hypoxic pressurized breathing training environment. The trainee inhales a hypoxic gas mixture prepared in real-time from ambient air, with precisely controllable concentration and flow rate, while simultaneously experiencing a stable additional load during exhalation. The entire system operates automatically, continuously, and stably under centralized PLC scheduling and multi-loop control. When training ends, the PLC controls each actuator to reset in an orderly manner: closing the gas supply solenoid valve A, switching the exhalation three-way valve back to the normal pressure position, gradually stopping the operation of components such as the air compressor, and the device returns to standby mode.

[0071] In summary, this application's embodiments achieve the core objective of on-site preparation of precise and controllable training gas using ambient air as the sole raw material through fully automated integration of air pretreatment, membrane separation, intelligent mixing, and resistance adjustment. This device not only completely eliminates dependence on traditional bottled gas sources, solving the inherent problems of difficult gas source acquisition, frequent gas exchange, and safety hazards, but also ensures high precision and long-term stability of the output gas in terms of concentration, flow rate, and breathing resistance through intelligent closed-loop control. Its integrated design significantly enhances the equipment's deployment capabilities and ease of use in special environments such as high-altitude and remote areas, providing users with a safe, reliable, efficient, and economical training support method.

[0072] In the description of this specification, the references to "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0074] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0075] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0076] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0077] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device, characterized in that, include: The system includes an air pretreatment module, a hollow fiber membrane separation module, a gas mixing module, an expiratory resistance adjustment module, an intelligent control module, and a gas path system; among which, The air pretreatment module is used to filter, compress, cool, and remove impurities from external air, and output pure, stable-pressure compressed air. The hollow fiber membrane separation module is used to receive pure, pressure-stabilized compressed air output from the air pretreatment module, and separates high-concentration nitrogen and high-concentration oxygen by utilizing the differences in gas permeation rates of different hollow fiber membranes. The gas mixing module is used to receive the high-concentration nitrogen and high-concentration oxygen, and mix them evenly according to a preset ratio to generate a nitrogen-oxygen mixed gas that meets the training requirements. The expiratory resistance adjustment module is used to provide adjustable expiratory resistance for training, adapting to both normobaric and pressurized breathing training modes. The intelligent control module is used to collect the operating parameters of each module of the device, and through a precise control algorithm, coordinate the operation of the air pretreatment module, hollow fiber membrane separation module, gas mixing module and expiratory resistance adjustment module to match the gas concentration, flow rate and pressure requirements required for training. The gas path system is used to connect various functional modules, forming a pathway for gas source preparation, gas separation, mixing output, and exhalation regulation, ensuring stable gas transmission.

2. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 1, characterized in that, The air pretreatment module includes a primary air filter, a variable frequency oil-free scroll air compressor, a cooler, a multi-stage impurity removal device, and a one-way valve A. The primary air filter removes fine particles and suspended matter from the air. The variable frequency oil-free scroll air compressor compresses the filtered air to a set pressure and stabilizes the output pressure through frequency conversion control. The cooler lowers the temperature of the compressed air, promoting the precipitation of water and oil mist molecules. The multi-stage impurity removal device removes droplets, oil, and ultrafine nanoparticles from the compressed air. The one-way valve A prevents backflow of gas at the downstream end.

3. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 2, characterized in that, The cooler uses a combination of air-cooled coils and semiconductor refrigeration modules to cool the compressed air temperature to a preset range. It works in conjunction with a temperature sensor for temperature control to ensure the effectiveness of compressed air pretreatment.

4. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 1, characterized in that, The hollow fiber membrane separation module includes a hollow fiber nitrogen membrane, a hollow fiber oxygen membrane, an electro-proportional valve group, and a one-way valve group. The hollow fiber nitrogen membrane separates nitrogen from the air, outputting a high-concentration nitrogen flow; the hollow fiber oxygen membrane separates oxygen from the air, outputting a high-concentration oxygen flow. The electro-proportional valve group includes multiple electro-proportional valves installed on the inlet and outlet gas passages of the hollow fiber nitrogen and oxygen membranes, respectively used to regulate the inlet and outlet pressures of the two hollow fiber membranes, establishing a pressure difference between the inside and outside of the membranes. The one-way valve group includes one-way valves B and C installed on the two high-concentration gas output pipelines to prevent gas backflow.

5. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 4, characterized in that, The hollow fiber nitrogen membrane is used to discharge useless gas on the permeation side and to enrich the target gas on the retention side. The hollow fiber oxygen membrane is used to enrich the target gas on the permeation side and to discharge useless gas on the retention side.

6. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 1, characterized in that, The gas mixing module includes a gas mass flow controller group, a mixing chamber, a concentration and pressure monitoring component, and a solenoid valve group. The gas mass flow controller group includes gas mass flow controllers A and B, respectively connected to the output ends of the hollow fiber nitrogen membrane and the hollow fiber oxygen membrane, for regulating the output flow rates of high-concentration nitrogen and high-concentration oxygen. The mixing chamber is used for uniform mixing of the two gases. The concentration and pressure monitoring component includes an oxygen concentration sensor, a pressure sensor B, a safety valve A, and a pressure gauge B, for monitoring the oxygen concentration and pressure of the mixed gas. The solenoid valve group includes a first solenoid valve and a second solenoid valve, located on the output pipeline of the mixing chamber, for controlling the opening and closing of the mixed gas output path.

7. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 1, characterized in that, The expiratory resistance adjustment module includes a pressure regulating valve, an electro-proportional valve E, a one-way valve D, a three-way valve, and safety protection components. The pressure regulating valve stabilizes the input pressure at a preset value, providing a base pressure for precise adjustment of downstream resistance. The electro-proportional valve E precisely controls expiratory resistance. The one-way valve D prevents backflow of gas in the airway. The three-way valve switches between normal pressure breathing and pressurized breathing pathways. The safety protection components include a safety valve B and a pressure gauge C, used to prevent excessively high expiratory pressure and monitor changes in expiratory pressure.

8. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 1, characterized in that, The intelligent control module includes a PLC controller, a parameter acquisition unit, an optimization control unit, and an instruction execution unit. The PLC controller serves as the main control unit. The parameter acquisition unit collects real-time operating data of the control device through pressure sensors, temperature sensors, oxygen concentration sensors, and a gas mass flow controller. The optimization control unit calculates the optimal operating parameters of each actuator based on preset training parameters and collected data using an algorithm. The instruction execution unit sends control instructions to the frequency converter, driver, electro-proportional valve, gas mass flow controller, and solenoid valve.

9. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 8, characterized in that, The optimized control unit supports reverse calculation of target parameters. Based on the preset oxygen concentration, total flow rate, and expiratory resistance of the mixed gas, it calculates the required inlet pressure, exhaust pressure, and adjustment parameters of gas mass flow controllers A and B for the hollow fiber membrane separation module, thus achieving precise control. The oxygen concentration of the mixed gas is controlled within the range of 5% to 40%, the total flow rate is controlled within the range of 0 to 30 liters / minute, and the expiratory resistance is controlled within the range of 0 to 18 kPa.

10. The hollow fiber membrane nitrogen-oxygen gas separation and mixing intelligent control device according to claim 1, characterized in that, The air supply system includes a constant-pressure variable-frequency air supply circuit, an air-separation mixing circuit, and an exhalation resistance regulating circuit. The constant-pressure variable-frequency air supply circuit connects in series with a primary air filter, a variable-frequency oil-free scroll air compressor, a cooler, a multi-stage impurity removal device, and a one-way valve A to output pure, stable-pressure compressed air. The air-separation mixing circuit connects to a hollow fiber nitrogen membrane and a hollow fiber oxygen membrane via branch structures, then converges into the mixing chamber via a gas mass flow controller group, and finally connects to the breathing mask's air supply port. The exhalation resistance regulating circuit connects in series with a pressure regulating valve, an electro-proportional valve E, a one-way valve D, and a three-way valve, and connects to the breathing mask's exhalation interface.

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