Local space oxygen-enrichment control system and control method based on oxygen-selective permeation membrane

Abstract

The application discloses a kind of local space oxygen-enriched control system and control method based on oxygen selective permeation membrane, belongs to air purification, environmental control and membrane separation technical field, for the problem that prior art cannot actively and efficiently improve indoor oxygen concentration and is difficult to compact integration.The system of the present application integrates outdoor fresh air fan, switching valve, oxygen-enriched membrane device, air pump, indoor return air and air supply fan, gas monitoring control unit, outdoor exhaust fan and other components, the control unit is based on the difference between oxygen sensor data and preset target oxygen concentration, dynamically regulates and controls switching valve passage, fan speed and air pump start-stop, selectively makes air through oxygen-enriched membrane device to produce oxygen-enriched air or through bypass air path into indoor, actively stabilizes indoor oxygen concentration at 21% to 26%.The system is suitable for residential, office and other local space, can realize active oxygen-enriched and environmental control, improve air quality while taking into account low energy consumption and safety and comfort.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of air purification, environmental control and membrane separation technology, and particularly relates to a local space oxygen enrichment control system based on oxygen-selective permeation membrane. BACKGROUND

[0002] At present, some air conditioning systems use fresh air ventilation to improve indoor air quality, but such systems can usually only maintain the indoor oxygen concentration at a level close to that of outdoor air, about 20.8% to 21%. When the outdoor air oxygen concentration is low, or the indoor personnel density is high and the oxygen consumption increases, such systems are difficult to actively and effectively improve the indoor oxygen concentration, and cannot meet the environmental demand for higher oxygen concentration in specific scenarios.

[0003] To solve the problem of indoor oxygen concentration improvement, some technical solutions use molecular sieve pressure swing adsorption oxygen production technology. However, this type of technology has some inherent difficulties: the oxygen production process usually involves high energy consumption, and the molecular sieve as the core consumable needs to be replaced regularly, increasing the complexity and cost of long-term maintenance. In addition, the molecular sieve-based system is usually large in volume and weight, and when it is integrated into a local environment with strict space limitations (such as a window or wall system using an embedded structure), it faces significant compact design difficulties. Therefore, in a limited installation space, it is a technical challenge to achieve low-energy, low-maintenance air conditioning functions that can actively improve oxygen concentration. SUMMARY

[0004] An object of the present application is to solve at least the above problems and to provide at least the advantages described later.

[0005] Another object of the present application is to provide a local space oxygen enrichment control system based on oxygen-selective permeation membrane, which can actively and accurately improve the indoor oxygen concentration through oxygen-selective permeation membrane, effectively save installation space through embedded structure design, and balance energy efficiency and operation safety while achieving oxygen enrichment function through intelligent control strategy.

[0006] To achieve these objects and other advantages of the present application, a local space oxygen enrichment control system based on oxygen-selective permeation membrane is provided, which includes:

[0007] An outdoor fresh air fan, the outlet of which is connected to the inlet of a switching valve, the switching valve including a first outlet and a second outlet;

[0008] An indoor supply air fan, the inlet of which is connected to the first outlet of the switching valve to form a bypass air path, and the outlet of the indoor supply air fan leads to the indoor;

[0009] An oxygen-enriched membrane device, an inlet of which is connected to a second outlet of the switching valve, the oxygen-enriched membrane device being provided with an oxygen outlet and a waste gas discharge outlet;

[0010] A gas pump, an inlet of which is connected to the oxygen outlet of the oxygen-enriched membrane device, and an outlet of which is connected to an inlet of the indoor air supply fan;

[0011] An indoor return air fan, an inlet of which leads to the indoor space;

[0012] A gas monitoring unit and a control unit, an inlet of which is connected to an outlet of the indoor return air fan, the gas monitoring unit and the control unit comprising an oxygen sensor and a carbon dioxide sensor;

[0013] An outdoor exhaust fan, an inlet of which is connected to an outlet of the gas monitoring unit and the control unit and a waste gas discharge outlet of the oxygen-enriched membrane device through pipelines respectively, and an outlet of which leads to the outdoor space;

[0014] A housing member for wrapping and fixing the outdoor fresh air fan, the switching valve, the indoor air supply fan, the oxygen-enriched membrane device, the gas pump, the indoor return air fan, the gas monitoring unit and the control unit, and the outdoor exhaust fan;

[0015] The control unit is configured to control the position of the switching valve according to the difference between the oxygen concentration measured by the oxygen sensor and the preset target oxygen concentration, and whether the concentration measured by the carbon dioxide sensor exceeds the preset limit value, and to control the rotation speed of the outdoor fresh air fan, the indoor return air fan, the indoor air supply fan and the outdoor exhaust fan through the frequency converter to control the air volume, and to control the start and stop of the gas pump; the preset target oxygen concentration is 21% to 26%, and the preset limit value of the carbon dioxide concentration is 1000 ppm.

[0016] The present application separates oxygen-rich air from air by adopting an oxygen-rich membrane device with oxygen-nitrogen separation characteristics and connecting a gas pump to the oxygen outlet side of the oxygen-rich membrane device to apply negative pressure; by setting a gas monitoring unit comprising an oxygen sensor and a carbon dioxide sensor, the indoor environment state is fed back in real time; the control unit dynamically controls the switching valve to select whether air flows through the oxygen-rich membrane device according to the difference between the monitoring data and the preset target, and adjusts the rotation speed of the outdoor fresh air fan, the indoor return air fan, the indoor supply air fan and the outdoor exhaust fan through the frequency converter, and controls the start and stop and power of the gas pump. This closed-loop control mechanism enables the system to actively and accurately increase the indoor oxygen concentration to a set range of 21% to 26% according to the actual demand, and automatically switches to a safe dilution mode when the concentration exceeds 26.5% or the carbon dioxide exceeds the standard. The oxygen concentration in the local space is actively increased on demand, overcoming the limitations of passive maintenance of traditional systems; through the combination of membrane separation technology and intelligent air volume adjustment, the oxygen-rich target is achieved while the operation energy efficiency is considered; the integrated module design facilitates embedding into the building structure, saving indoor space; multiple safety interlocking controls effectively ensure the reliable operation of the system and prevent the risk of high oxygen concentration.

[0017] Preferably, it further comprises:

[0018] The filter structure comprises a primary filter screen and a HEPA activated carbon composite filter screen, and the outlet of the outdoor fresh air fan is connected to the inlet of the primary filter screen, and the outlet of the primary filter screen is connected to the inlet of the HEPA activated carbon composite filter screen.

[0019] The fresh air inlet of the total heat exchanger is connected to the outlet of the HEPA activated carbon composite filter screen, and the fresh air outlet of the total heat exchanger is connected to the inlet of the switching valve.

[0020] The present application sets a filter structure comprising a primary filter screen and a HEPA activated carbon composite filter screen, which performs two-stage purification from coarse to fine on the introduced outdoor air, effectively removing particulate matter and adsorbing volatile organic compounds; meanwhile, a total heat exchanger is additionally provided, and its fresh air inlet is connected after the filter structure, and the core material of the total heat exchanger exchanges heat and humidity between the fresh air and the indoor exhaust air without mixing. This configuration enables the system to recover most of the energy in the exhaust air while providing clean fresh air, significantly reducing the additional energy consumption for adjusting the temperature and humidity of the fresh air, thereby further improving the overall energy efficiency and economy of the system while ensuring indoor air cleanliness and oxygen enrichment function.

[0021] Preferably, the shell member comprises:

[0022] The shell is used for embedding into a window or a wall;

[0023] The inner shell, located inside the outer shell, is used to fix the outdoor fresh air fan, switching valve, indoor air supply fan, oxygen enrichment membrane device, air pump, indoor return air fan, gas monitoring unit and control unit, and outdoor exhaust fan.

[0024] The sound-insulating layer is filled between the outer shell and the inner shell.

[0025] This invention optimizes the shell structure, specifically employing an outer shell for embedding into windows or walls to provide primary support, and an independent inner shell inside to secure all functional components. Simultaneously, a sound-insulating layer is filled in the cavity between the inner and outer shells. This design, through the physical separation of the inner and outer shells and the acoustic damping effect of the sound-insulating cotton, effectively blocks and absorbs structural and airborne sound generated during equipment operation. Thus, while maintaining all system functions and a compact structure, it significantly reduces operational noise transmitted into the indoor space, improving the user experience in quiet environments such as bedrooms.

[0026] Preferably, when the oxygen concentration is lower than the preset target oxygen concentration, the control unit controls the switching valve to connect its inlet to the second outlet, and starts the air pump or increases the power of the air pump so that air flows through the oxygen-enriched membrane device to generate oxygen-enriched air. When the oxygen concentration is ≥26.5% or the carbon dioxide concentration exceeds the preset limit, the control unit controls the switching valve to connect its inlet to the first outlet, and reduces the power of the air pump or shuts down the air pump so that air enters the room through the bypass ventilation path.

[0027] The oxygen-enriched membrane device uses a polymer membrane, and the oxygen permeability of the polymer membrane is 4. Up to 5 The oxygen-nitrogen separation coefficient is 2.1.

[0028] This invention clarifies the specific judgment logic and execution strategy of the control unit: when the oxygen concentration is lower than the target, the control switching valve connects to the oxygen-enriched membrane device path and starts or increases the power of the air pump to actively increase oxygen; when the oxygen concentration is ≥26.5% or the carbon dioxide exceeds the limit, the control switching valve switches to the bypass ventilation path and reduces or shuts down the air pump, diluting the oxygen by introducing a large amount of ordinary air. Furthermore, by limiting the use of a polymer membrane with specific oxygen permeability and oxygen-nitrogen separation coefficient in the oxygen-enriched membrane device, the efficiency of the gas separation process and the controllability of the oxygen-enriched air concentration are ensured at the material level. This refined control strategy, combined with the clear limitation of the core component performance, enables the system to maintain the target oxygen concentration range more smoothly and stably, avoiding control oscillations. Simultaneously, the high selectivity of the membrane material ensures the efficiency and safety of oxygen-enriched output at the source, preventing the risk of excessive oxygen enrichment and improving the overall control accuracy and reliability.

[0029] Preferably, the control unit is configured to receive a scene mode instruction sent by a user through a remote terminal or a control panel, the scene mode including a sleep mode, a learning mode and an exercise mode, and the control unit pre-stores a target oxygen concentration range and a wind volume parameter mapping table corresponding to the scene mode;

[0030] wherein the target oxygen concentration range corresponding to the sleep mode is 21.0% to 22.0%, and the combined operation wind volume of the outdoor fresh air fan and the indoor return air fan is controlled at 80 m 3 / h to 120 m 3 / h;

[0031] The target oxygen concentration range corresponding to the learning mode is 22.5% to 23.5%, and the combined operation wind volume is controlled at 150 m 3 / h to 200 m 3 / h;

[0032] The target oxygen concentration range corresponding to the exercise mode is 24.0% to 25.5%, and the combined operation wind volume is controlled at 220 m 3 / h to 300 m 3 / h;

[0033] The control unit is configured to: after receiving the scene mode instruction selected by the user, call the corresponding mapping table, set the target oxygen concentration of the system to the range corresponding to the selected mode, and adjust the combined operation wind volume to the wind volume range corresponding to the selected mode;

[0034] When the system is running in any scene mode, the control unit continuously compares the real-time oxygen concentration measured by the oxygen sensor with the target oxygen concentration range of the current mode.

[0035] When the real-time oxygen concentration continuously falls below the lower limit value of the current target oxygen concentration range for a first preset duration, the control unit controls the switching valve to switch to the path in which air flows through the oxygen enrichment membrane device, and starts or increases the power of the air pump to increase the supply of oxygen-enriched air.

[0036] When the real-time oxygen concentration continuously rises above the upper limit value of the current target oxygen concentration range for a second preset duration, the control unit controls the switching valve to switch to the bypass air path, and reduces the power of the air pump or turns off the air pump.

[0037] The first preset duration is 30 s to 90 s, and the second preset duration is 20 s to 60 s.

[0038] The application pre-stores a target oxygen concentration range and air volume parameter mapping table corresponding to specific scene modes such as sleep, learning and exercise in the control unit, so that the user can select a mode through an instruction; the control unit then calls the corresponding parameters as set points, and automatically adjusts the system target oxygen concentration and the combined operation air volume to a range matched with the physiological scene. Further, the control logic introduces a duration-based judgment mechanism, and only when the real-time oxygen concentration continuously deviates from the target range for a first or second preset duration, the oxygen enrichment or dilution operation is triggered. In this way, the system can automatically switch the environment regulation strategy according to the explicit activity state intention of the user, realizes on-demand supply and dynamic optimization, effectively improves the individual comfort and system adaptability in different use scenarios, and at the same time avoids frequent start-stop of the equipment caused by instantaneous fluctuation of the parameters, enhances the operation stability and energy efficiency.

[0039] Preferably, the gas monitoring unit and the control unit further comprise an indoor temperature and humidity sensor, a formaldehyde sensor, a PM2.5 sensor, a TVOC sensor and a carbon monoxide sensor;

[0040] The control unit is configured to execute the following control logic:

[0041] Firstly, it is judged whether the real-time concentration measured by the carbon monoxide sensor exceeds its corresponding threshold value 10 ppm;

[0042] If it exceeds, the control unit ignores the current oxygen concentration value, and forcibly switches the system to a high-speed ventilation mode, which includes controlling the switching valve to switch to the bypass air path, closing the gas pump, and increasing the combined operation air volume of the outdoor fresh air fan and the indoor return air fan to 90% to 100% of the system rated maximum air volume;

[0043] If it does not exceed, the control unit sequentially judges whether at least one of the formaldehyde concentration, the TVOC concentration and the PM2.5 concentration exceeds its corresponding threshold value; if any of the pollutant concentrations exceeds the standard, the control unit increases the combined operation air volume of the outdoor fresh air fan and the indoor return air fan while maintaining the current oxygen concentration control target, and the increase amplitude is positively correlated with the type and the exceeding amplitude of the exceeding pollutant; the formaldehyde threshold value is 0.08 mg / m 3 , the TVOC threshold value is 0.6 mg / m 3 , and the PM2.5 threshold value is 35 μg / m 3 ;

[0044] If all the pollutant concentrations do not exceed the standard, and the indoor temperature measured by the temperature and humidity sensor is lower than 18 ℃ or higher than 28 ℃, or the indoor relative humidity is lower than 40% or higher than 70%, the control unit adjusts the fan speed of the total heat exchanger or sends a control signal to the building central air conditioning system to cooperatively adjust the temperature and humidity while maintaining the current oxygen concentration control target.

[0045] The application adds indoor temperature and humidity, formaldehyde, PM2.5, TVOC and carbon monoxide sensors in the gas monitoring unit, and establishes a serial judgment logic based on safety priority: the control unit first judges whether the carbon monoxide concentration exceeds the safety threshold, if it exceeds the standard, it ignores the current oxygen concentration, and forcibly switches to the high-speed ventilation mode to prioritize the removal of toxic gases; if it does not exceed the standard, it judges in order whether other pollutants exceed the standard, and increases the air volume as needed to dilute under the premise of maintaining the oxygen concentration target; if all pollutants do not exceed the standard but the temperature and humidity are not suitable, adjust with the total heat exchanger or central air conditioner. This hierarchical conditional judgment logic integrates multiple sensor data into a single, clear execution instruction, ensuring that the system can always prioritize the most urgent safety risks under complex working conditions, and does not affect the stability of the core oxygen enrichment function when solving non-core environmental problems, thereby achieving the uniqueness of decision-making and the safety of operation of multi-target control.

[0046] Preferably, the control unit has pre-stored mapping relationships between the reference concentration thresholds of at least three pollutants and the air volume adjustment coefficients, including formaldehyde, TVOC and PM2.5;

[0047] The control unit is configured to execute the following air volume coordinated control strategy when it is determined that any of the pollutant concentrations exceeds the standard:

[0048] First, calculate the over-standard multiple of the current over-standard pollutant, which is the real-time concentration value of the pollutant divided by its corresponding reference concentration threshold;

[0049] Second, according to the type of the over-standard pollutant, obtain the corresponding air volume adjustment coefficient from the mapping relationship; wherein the air volume adjustment coefficient corresponding to formaldehyde is 1.5 to 2.0, the air volume adjustment coefficient corresponding to TVOC is 1.2 to 1.6, and the air volume adjustment coefficient corresponding to PM2.5 is 1.0 to 1.4;

[0050] Then, multiply the over-standard multiple by the corresponding air volume adjustment coefficient to obtain the theoretical air volume increase ratio of the pollutant;

[0051] If multiple pollutants exceed the standard at the same time, take the maximum value of all the theoretical air volume increase ratios as the final air volume increase ratio;

[0052] Finally, according to the final air volume increase ratio, increase the joint operation air volume of the outdoor fresh air fan and the indoor return air fan under the premise of maintaining the current oxygen concentration control target, and the joint operation air volume after the increase should not exceed 70% of the system rated maximum air volume, wherein the system rated maximum air volume is the sum of the maximum design air volume of the outdoor fresh air fan and the indoor return air fan;

[0053] The control unit continues to monitor the oxygen concentration change while increasing the air volume to handle the excessive pollutants, and if the oxygen concentration deviates from the current target range due to the increase in air volume, the air volume increase operation is preferentially maintained, and the air pump is started to compensate for the deviation of the oxygen concentration.

[0054] The present application establishes a quantitative air volume coordinated regulation strategy: the control unit calculates the theoretical air volume increase ratio according to the types and over-standard multiples of the excessive pollutants, combines the pre-stored air volume adjustment coefficients corresponding to different pollutants, takes the maximum value as the final increase basis when multiple pollutants are excessive at the same time, and restricts the upper limit of air volume increase within 70% of the system rated maximum air volume. When executing the air volume increase operation, the system continuously monitors the oxygen concentration change, and if the oxygen concentration deviates due to the increase in air volume, the air volume required for pollutant removal is preferentially maintained, and the air pump is started to actively compensate for the deviation of the oxygen concentration. This method establishes a dynamic balance mechanism between increasing ventilation and maintaining stable oxygen concentration, so that the system can effectively dilute pollutants while timely offsetting the negative impact of fresh air dilution on oxygen concentration, thereby achieving efficient pollutant removal and stable core oxygen enrichment target.

[0055] Preferably, the switching valve is an adjustable damper for controlling the proportion of air flowing through the oxygen-enriching membrane device;

[0056] The control unit is configured to execute the following oxygen concentration deviation compensation mechanism when executing air volume increase to handle excessive pollutants:

[0057] First, the control unit calculates the deviation value of the current oxygen concentration from the lower limit of the target oxygen concentration range in real time. When the deviation value reaches-2.0 percentage points, the control unit starts the first compensation strategy, which includes starting the air pump and adjusting the negative pressure of the air pump to the range of-60 kPa to-70 kPa;

[0058] If the deviation value does not decrease to within-1.0 percentage points within 10 s after executing the first compensation strategy, the control unit starts the second compensation strategy, which includes increasing the negative pressure of the air pump to the range of-71 kPa to-81 kPa, and increasing the proportion of air flowing through the oxygen-enriching membrane device by 20% to 40% by adjusting the adjustable damper;

[0059] The control unit maintains the increased combined operation air volume for handling excessive pollutants unchanged during the execution of the compensation strategy;

[0060] If the deviation value continues to expand to-3.0 percentage points and maintains for 5 s to 15 s, the control unit determines that the compensation is invalid, and executes a safety intervention measure, which includes gradually reducing the combined operation air volume until the oxygen concentration returns to the target range;

[0061] The control unit records the duration and compensation effect of each compensation operation, and dynamically adjusts the starting threshold and parameters to optimize the compensation effect according to the historical compensation data.

[0062] The present application introduces a hierarchical oxygen concentration deviation compensation mechanism: the control unit calculates the oxygen concentration deviation in real time, and when it reaches-2.0 percentage points, the first level compensation is started, that is, the air pump is started and a specific negative pressure range is set; if the compensation effect is insufficient, the second level compensation is upgraded, further increasing the air pump negative pressure and adjusting the damper to increase the proportion of air flowing through the oxygen enrichment membrane device. During the entire compensation process, the air volume increased for pollutant treatment remains unchanged. If the deviation continues to deteriorate to-3.0 percentage points, the system determines that the compensation has failed and performs safety intervention, gradually reducing the air volume until the oxygen concentration is restored. In addition, the system dynamically optimizes the compensation parameters by recording historical compensation data. This hierarchical mechanism dynamically combines and adjusts the means according to the degree of deviation, enhancing the system's rapid response and oxygen enrichment compensation ability under complex working conditions, effectively ensuring the stability of the oxygen concentration while adhering to the priority of pollutant removal, achieving adaptive optimization and operation reliability of multi-objective control.

[0063] Preferably, it also includes an outdoor temperature and humidity sensor for measuring outdoor temperature and relative humidity;

[0064] The control unit adjusts the operating state of the total heat exchanger or adjusts the air volume while maintaining the current oxygen concentration control target, and the specific process of cooperating with the building central air conditioning system for temperature and humidity regulation includes:

[0065] The control unit is configured to perform the following temperature and humidity cooperative control logic:

[0066] First, the indoor temperature value and indoor relative humidity value measured by the temperature and humidity sensor are monitored in real time;

[0067] If the indoor temperature value is below 18 ℃ or above 28 ℃ for a duration of a third preset time length, or the indoor relative humidity value is below 40% or above 70% for a duration of a third preset time length, the control unit starts the temperature and humidity regulation mode while maintaining the current oxygen concentration control target;

[0068] The temperature and humidity regulation mode includes the following operations:

[0069] When temperature needs to be adjusted, the control unit first compares the indoor temperature value with the outdoor temperature value; if the indoor temperature value is higher than the outdoor temperature value, the control unit preferentially selects to increase the combined running air volume of the outdoor fresh air fan and the indoor return air fan, so that it is positively adjusted within the range of 0% to positive 30% of the system rated air volume, to introduce more low-temperature outdoor air for cooling; if the indoor temperature value is lower than the outdoor temperature value, the control unit preferentially selects to adjust the fan speed associated with the heat exchanger, so that it is linearly adjusted within the range of 50% to 100% of the rated speed, to improve the heat recovery efficiency and reduce the indoor heat loss;

[0070] When humidity needs to be adjusted, the control unit first compares the indoor relative humidity value with the outdoor relative humidity value; if the indoor relative humidity value is higher than the outdoor relative humidity value, the control unit preferentially selects to increase the combined running air volume of the outdoor fresh air fan and the indoor return air fan, so that it is positively adjusted within the range of 0% to positive 25% of the system rated air volume, to introduce drier outdoor air for dehumidification; if the indoor relative humidity value is lower than the outdoor relative humidity value, the control unit preferentially selects to adjust the speed of the internal fan of the heat exchanger, so that it is linearly adjusted within the range of 60% to 100% of the rated speed, to improve the humidity exchange efficiency and maintain the indoor humidity;

[0071] When the control unit executes the temperature and humidity adjustment mode, it continuously compares the real-time oxygen concentration measured by the oxygen sensor with the current target oxygen concentration range; if the real-time oxygen concentration continuously falls below the lower limit value of the current target oxygen concentration range for 10 s or continuously rises above the upper limit value of the current target oxygen concentration range for 10 s due to the execution of the temperature and humidity adjustment operation, the control unit immediately terminates the current temperature and humidity adjustment operation, and restores the speed of the internal fan of the heat exchanger and the combined running air volume of the outdoor fresh air fan and the indoor return air fan to the parameter setting values before the temperature and humidity adjustment mode is started.

[0072] The third preset time length is 5 min to 15 min.

[0073] The application adds an outdoor temperature and humidity sensor and establishes a directional regulation strategy based on physical laws: the control unit first compares the indoor and outdoor temperature and humidity values, when cooling or dehumidifying is needed, if the outdoor conditions are more favorable, the combined air volume of fresh air and return air is preferentially increased to introduce low-temperature or dry air, when heat preservation or humidification is needed, the fan speed of the total heat exchanger is preferentially adjusted to improve the heat recovery or humidity retention efficiency. At the same time, the logic sets a third preset time as the starting condition and continuously monitors the oxygen concentration change, and once the oxygen concentration deviates from the target range due to temperature and humidity regulation, the current operation is terminated and the original parameters are restored. The directional regulation mechanism based on real-time comparison of indoor and outdoor parameters ensures the correctness of each temperature and humidity intervention in physical principles, avoids the invalid dissipation of energy, maintains the oxygen concentration control core target, and realizes the energy efficiency of the building central air conditioning system, improves the rationality and economy of the overall environmental regulation.

[0074] A control method of a local space oxygen enrichment control system based on an oxygen-selective permeation membrane, the method comprising the following steps:

[0075] Real-time monitoring of indoor oxygen concentration and carbon dioxide concentration by a gas monitoring unit;

[0076] The control unit compares the monitored oxygen concentration with the preset target oxygen concentration, wherein the preset target oxygen concentration is 21% to 26%;

[0077] When the monitored oxygen concentration is lower than the preset target oxygen concentration, the control unit controls the switching valve to switch to the path of air flowing through the oxygen enrichment membrane device, starts the gas pump, and adjusts the air volume of the outdoor fresh air fan, the indoor return air fan, the indoor supply air fan and the outdoor exhaust air fan;

[0078] The gas pump applies a negative pressure at the oxygen outlet of the oxygen enrichment membrane device, the negative pressure range is-60 kPa to-81 kPa, the oxygen enrichment membrane device separates oxygen-enriched air from air, and the oxygen-enriched air is sent into the indoor supply air fan and into the indoor by the gas pump;

[0079] When the monitored oxygen concentration is greater than or equal to 26.5% or the carbon dioxide concentration exceeds the preset limit value, the control unit controls the switching valve to switch to the bypass air path, reduces the negative pressure of the gas pump or closes it, so that air enters the indoor directly through the bypass air path;

[0080] Real-time monitoring of indoor temperature, indoor relative humidity, carbon monoxide concentration, formaldehyde concentration, TVOC concentration and PM2.5 concentration by the gas monitoring unit;

[0081] When the carbon monoxide concentration exceeds its preset threshold, the control unit ignores the current oxygen concentration value, forces the control of the switching valve to switch to the bypass air path, closes the air pump, and increases the combined operation air volume of the outdoor fresh air fan and the indoor return air fan to 90% to 100% of the system rated maximum air volume;

[0082] When at least one of the formaldehyde concentration, the TVOC concentration, or the PM2.5 concentration exceeds its corresponding threshold, but the carbon monoxide concentration does not exceed its preset threshold, the control unit determines a final air volume increase ratio according to the type and the exceeding degree of the exceeding pollutant while maintaining the current oxygen concentration control target, and increases the combined operation air volume of the outdoor fresh air fan and the indoor return air fan, and the increased combined operation air volume cannot exceed 70% of the system rated maximum air volume, wherein the system rated maximum air volume is the sum of the maximum design air volumes of the outdoor fresh air fan and the indoor return air fan;

[0083] When all pollutant concentrations do not exceed the thresholds, and the indoor temperature continuously deviates from the range of 18 ℃ to 28 ℃ for 5 min to 15 min, or the indoor relative humidity continuously deviates from the range of 40% to 70% for 5 min to 15 min, the control unit starts the temperature and humidity adjustment mode by adjusting the operation state of the total heat exchanger or adjusting the air volume to adjust the temperature and humidity in cooperation with the building central air conditioning system while maintaining the current oxygen concentration control target.

[0084] The present application at least includes the following beneficial effects:

[0085] Firstly, the present application integrates the oxygen-enriching membrane device, multiple groups of fans, the gas monitoring unit, and the control unit in a unified shell, realizes the modularization and compactness of the system, and enables it to be directly embedded in the window or wall for installation, effectively overcoming the disadvantage of the traditional function separation system that occupies the effective use area of the room; through the closed-loop control based on sensor data to dynamically adjust the air volume and the operation state of the air pump, the system can accurately maintain the indoor oxygen concentration in the preset target interval, and can automatically switch to the safety dilution mode when the oxygen concentration or the pollutant concentration exceeds the threshold, thereby significantly improving the operation safety and the control intelligent level while realizing the active oxygen-enriching function; in addition, the system integrates the filtering structure and the total heat exchanger, realizes the efficient recovery of energy on the basis of providing clean fresh air and actively increasing the oxygen concentration, and supports the multi-scene operation mode of on-demand adjustment, and finally effectively reduces the overall operation energy consumption of the system on the premise of ensuring the indoor air health and comfort.

[0086] Secondly, the present application realizes systematic regulation by the following steps: first, always taking the real-time monitored indoor oxygen and carbon dioxide concentrations as the core basis, dynamically switching the oxygen enrichment path or bypass air path according to the difference between the same and the preset target, and adjusting the air volume and air pump negative pressure, to realize closed-loop control of oxygen concentration and safety limit protection; secondly, establishing a serial judgment and execution process: when the carbon monoxide concentration exceeds the standard, unconditionally forcing the system to enter the high-speed ventilation mode to eliminate the acute safety threat; for other pollutants exceeding the standard, diluting according to the calculated air volume increase ratio on the premise of maintaining the oxygen concentration target, and limiting the upper limit of the air volume increase to within 70% of the rated maximum air volume; finally, for the case of unsuitable temperature and humidity, starting the directional adjustment strategy based on indoor and outdoor comparison on the premise of ensuring the stability of the oxygen concentration. This method divides the multi-target control task into serial execution steps with clear priorities, and maintains the stability of the core target through the parallel running of the oxygen concentration compensation mechanism when executing non-core tasks, ensuring the orderliness of system decision-making, the uniqueness of instruction execution and the stability of overall control in a complex multi-parameter environment, and finally realizing the coordinated achievement of safety, health and comfort targets.

[0087] Other advantages, objects, and features of the present application will be understood by those skilled in the art from the following description, and will be appreciated upon reading and comprehending the attached drawings and the detailed description that follows. BRIEF DESCRIPTION OF DRAWINGS

[0088] Figure 1 Structure diagram of the local space oxygen enrichment control system based on the oxygen selective permeation membrane of the present application;

[0089] Figure 2 Structure front view of the local space oxygen enrichment control system based on the oxygen selective permeation membrane of the present application;

[0090] Figure 3 Structure diagram of the oxygen enrichment membrane device of the present application;

[0091] Figure 4 Control flow chart of the local space oxygen enrichment control system based on the oxygen selective permeation membrane of the present application;

[0092] Figure 5 Oxygen enrichment curve diagram of the simulation box.

[0093] 1, outdoor fresh air fan; 2, primary filter screen; 3, HEPA activated carbon composite filter screen; 4, gas monitoring unit and control unit; 5, indoor return air fan; 6, indoor supply air fan; 7, air pump; 8, oxygen enrichment membrane device; 801, air inlet; 802, oxygen outlet; 803, exhaust gas outlet; 804, high polymer membrane; 9, total heat exchanger; 10, outdoor exhaust air fan; 11, outer shell; 12, soundproof wool layer; 13, inner shell. DETAILED DESCRIPTION

[0094] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0095] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0096] like Figures 1-5 As shown, the present invention provides a localized spatial oxygen enrichment control system based on an oxygen-selective permeation membrane, the system comprising:

[0097] The outdoor fresh air fan 1 has its outlet connected to the inlet of a switching valve, which includes a first outlet and a second outlet.

[0098] An indoor air supply fan 6 has its inlet connected to the first outlet of a switching valve to form a bypass ventilation path, and the outlet of the indoor air supply fan 6 leads to the room.

[0099] The oxygen-enriched membrane device 8 has its inlet connected to the second outlet of the switching valve. The oxygen-enriched membrane device 8 is provided with an oxygen outlet 802 and a waste gas outlet 803.

[0100] Air pump 7, whose inlet is connected to the oxygen outlet 802 of oxygen enrichment membrane device 8, and whose outlet is connected to the inlet of indoor air supply fan 6;

[0101] Indoor return air fan 5, its inlet leads to the room;

[0102] The gas monitoring unit and control unit 4 has its inlet connected to the outlet of the indoor return air fan 5. The gas monitoring unit and control unit 4 includes an oxygen sensor and a carbon dioxide sensor.

[0103] The outdoor exhaust fan 10 has its inlet connected to the outlet of the gas monitoring unit and control unit 4 and the exhaust outlet 803 of the oxygen enrichment membrane device 8 via pipelines. The outlet of the outdoor exhaust fan 10 leads to the outside.

[0104] Housing components, which are used to enclose and fix the outdoor fresh air fan 1, switching valve, indoor air supply fan 6, oxygen enrichment membrane device 8, air pump 7, indoor return air fan 5, gas monitoring unit and control unit 4, and outdoor exhaust fan 10.

[0105] The control unit is configured to control the position of the switching valve according to the difference between the oxygen concentration measured by the oxygen sensor and the preset target oxygen concentration, and whether the concentration measured by the carbon dioxide sensor exceeds the preset limit value. The control unit adjusts the rotating speed of the outdoor fresh air fan 1, the indoor return air fan 5, the indoor supply air fan 6, and the outdoor exhaust air fan 10 through the frequency converter to control the air volume, and controls the start and stop of the air pump 7. The preset target oxygen concentration is 21% to 26%, and the preset limit value of the carbon dioxide concentration is 1000 ppm.

[0106] The outdoor fresh air fan 1 can adopt a direct-current brushless fan with an air volume in the range of 80 to 300 m 3 / h, and its outlet is connected to the inlet of the switching valve through a flange. The fan can be equipped with a frequency converter to adjust the input current frequency to continuously adjust the rotating speed between 800 to 2500 r / min.

[0107] The switching valve can adopt a three-way electromagnetic valve structure, including a first outlet and a second outlet. The valve body material can be selected from engineering plastics, and the sealing ring can be made of nitrile rubber. The first outlet is connected to the inlet of the indoor supply air fan 6 through a 80 mm diameter hose, and the second outlet is connected to the oxygen-enriching membrane device 8 through a pipe with the same specification.

[0108] The indoor supply air fan 6 can adopt a centrifugal fan, and its inlet is fixed on the hose connected to the first outlet through a clamp, and its outlet is connected to the air supply pipeline through a variable diameter joint. The fan impeller diameter can be selected as 80 mm, and the static pressure can reach 150 Pa under rated working conditions.

[0109] The oxygen-enriching membrane device 8 can be assembled by a high polymer membrane, which is purchased from Dalian Puricore Technology Co., Ltd. and is branded as GKSS. The filter membrane type is a high polymer flat plate oxygen-enriching membrane, which belongs to the EV75-3 series. The shell of the oxygen-enriching membrane device 8 can be made of aluminum alloy, and is provided with an air inlet 801, an oxygen outlet 802, and a waste gas outlet 803. During assembly, each interface is sealed by an O-ring, and the sealing pressure is not less than 0.6 MPa. The oxygen-enriching membrane device 8 is the core oxygen-increasing component of the system, and its specific structure is as shown in Figure 3The high polymer membrane 804 is arranged inside the device for oxygen-nitrogen separation. The working principle of the high polymer membrane is that the high polymer membrane realizes oxygen-nitrogen separation based on the difference in the gas solubility-diffusion mechanism in the membrane material: since the solubility and diffusion coefficient of oxygen molecules (O2) in the high polymer membrane material are higher than those of nitrogen molecules (N2), under the driving of the negative pressure applied by the air pump on the membrane permeation side, the oxygen molecules in the air preferentially permeate through the membrane wall, and form oxygen-enriched air on the inside of the membrane; and the nitrogen molecules are mainly trapped on the outside of the membrane due to the low permeation rate, and are finally discharged from the system through the exhaust gas outlet. Specifically, the air inlet 801 is connected with the fresh air outlet of the total heat exchanger 9, and receives the pretreated air filtered and energy recovered. The oxygen outlet 802 is connected with the inlet of the air pump 7. When the air pump 7 works, a negative pressure is formed on the side of the oxygen outlet 802, which drives the oxygen-enriched air permeating through the high polymer membrane 804 to flow to the air pump 7. The exhaust gas outlet 803 is connected with the outdoor exhaust fan 10 through a pipeline, and forcibly discharges the nitrogen-enriched gas remaining after separation to the outside. Figure 3 The arrangement of the high polymer membrane 804 inside the device is clearly shown. The bag-in-bag structure ensures that the gas flow has the best flow rate and reasonable flow channel distribution during the separation process, effectively alleviates the concentration polarization phenomenon, increases the effective contact area, thereby strengthening the mass transfer process, and ensures high separation efficiency.

[0110] The air pump 7 can adopt a rotary vane vacuum pump, the inlet of which is connected with the oxygen outlet 802 through a cone joint, and the outlet is connected with the inlet pipeline of the indoor air supply fan 6 in parallel through a quick plug joint. The pump can generate a vacuum degree of-60 to-81 KPa, and the power can be adjusted between 150 to 300 watts.

[0111] The indoor return air fan 5 can adopt an axial flow fan, and a louver grille can be arranged at the inlet of the fan and fixed to the return air opening of the inner shell 13 by self-tapping screws. The air volume of the fan can be adjusted within the range of 50 to 200 m 3 / h.

[0112] The gas monitoring unit and control unit 4 can include an oxygen sensor and a carbon dioxide sensor. The oxygen sensor can adopt an electrochemical principle, and the measurement range is 18% to 30% with an accuracy of ±0.2%. The carbon dioxide sensor can adopt a non-dispersive infrared principle, and the measurement range is 0 to 5000 ppm with an accuracy of ±50 ppm. The control unit can adopt a 32-bit microprocessor, and control the rotation speed of each fan through four PWM signals.

[0113] The outdoor exhaust fan 10 can adopt a mixed flow fan, and the inlet thereof is connected with the outlet of the gas monitoring unit and control unit 4 and the exhaust gas outlet 803 of the oxygen-enriched membrane device 8 through a Y-shaped tee joint. The air volume of the fan can be adjusted within the range of 100 to 350 m 3 / h.

[0114] The outer shell 11 of the shell member can be made of a 1.2 mm thick galvanized steel sheet, and the inner shell 13 can be made of a 0.8 mm thick aluminum alloy sheet. The sound insulation wool layer 12 can be made of glass wool with a density of 32 kg / m 3 When assembled, the inner shell 13 is first fixed, the sound insulation wool is filled, and then the outer shell 11 is packaged, and finally fixed with self-tapping screws at an interval of 150 mm.

[0115] The control unit can preset the target oxygen concentration to be 21% to 26%, and the carbon dioxide concentration limit value to be 1000 ppm. When the system is working, the control unit collects sensor data once every second: when the oxygen concentration is lower than the set value, the control switch valve is connected to the second outlet, and the air pump 7 is started at the same time; when the oxygen concentration is ≥26.5% or the carbon dioxide is over limit, the switch valve is connected to the first outlet, and the power of the air pump 7 is reduced at the same time. The rotation speed of each fan is adjusted in real time through the PID algorithm to ensure that the air supply is stable within ±5% of the set value.

[0116] In another technical solution, further, the system further comprises:

[0117] A filtering structure comprising a primary filter screen 2 and a HEPA activated carbon composite filter screen, the outlet of the outdoor fresh air fan 1 being connected to the inlet of the primary filter screen 2, and the outlet of the primary filter screen 2 being connected to the inlet of the HEPA activated carbon composite filter screen 3;

[0118] A total heat exchanger 9, the fresh air inlet of which is connected to the outlet of the HEPA activated carbon composite filter screen 3, and the fresh air outlet of the total heat exchanger 9 is connected to the inlet of the switch valve.

[0119] The filtering structure can comprise a primary filter screen 2 and a HEPA activated carbon composite filter screen 3. The primary filter screen 2 can be made of polyester fiber material with a thickness of 10 to 15 mm, a filtration grade of G4, and an initial resistance of 20 to 30 Pa. The filter screen can be installed at the outlet pipe of the outdoor fresh air fan 1 and fixed in the installation frame through a buckle type structure to ensure that the four sealing strips are tightly attached to the frame to prevent air flow short circuiting.

[0120] The HEPA activated carbon composite filter screen 3 can be made of a composite structure of glass fiber filter paper and granular activated carbon, with a filter paper thickness of 50 mm and an activated carbon layer weight of 300 to 500 g / m 2 . The filter screen can achieve a H13 filtration grade, and the filtration efficiency of 0.3 micron particulate matter meets the relevant standard requirements. When assembled, it is installed at the downstream position of the primary filter screen 2 using a sliding rail type installation method, and a closed cell sponge rubber sealing strip is added around the filter screen.

[0121] The total heat exchanger 9 can adopt a cross-flow core structure, and the core material can be selected from special paper materials or aluminum alloy foil materials. The core size can be selected according to the system air volume, and common specifications include 300 mm x 300 mm x 200 mm and 400 mm x 400 mm x 200 mm. The temperature exchange efficiency can meet the corresponding industry standard requirements under standard working conditions, and the humidity exchange efficiency also meets the conventional technical indicators.

[0122] The fresh air inlet of the total heat exchanger 9 is connected to the outlet of the HEPA activated carbon composite filter screen 3 through a flange, and the fresh air outlet is connected to the inlet of the switching valve through a reducing joint.

[0123] During system operation, outdoor air passes through the primary filter screen 2 and the HEPA activated carbon composite filter screen 3 in sequence. The primary filter screen 2 mainly intercepts particulate matter above 5 microns, including pollen, dust and other large particles. The HEPA activated carbon composite filter screen 3 further filters fine particulate matter and adsorbs gaseous pollutants such as formaldehyde and sulfur dioxide, with an adsorption capacity of 200 to 400 mg / g. The filtered air enters the fresh air channel of the total heat exchanger 9 and exchanges heat and humidity with the air discharged from the indoor return air channel, achieving energy recovery. The resistance of the filter structure gradually increases with the increase of the use time. The system can be equipped with a differential pressure sensor to monitor the filter resistance, and the sensor range can be selected from 0 to 200 Pa with an accuracy of ± 2 Pa. The primary filter screen 2 needs to be replaced when the resistance reaches 80 Pa, and the HEPA activated carbon composite filter screen 3 is recommended to be replaced when the resistance reaches 150 Pa. The core of the total heat exchanger 9 can be regularly cleaned and maintained, and the cleaning period is recommended to be 3 to 6 months. During cleaning, compressed air is used for reverse blowing, and the blowing pressure is controlled between 0.2 and 0.4 MPa.

[0124] The system realizes energy recovery while providing clean air through the combination of two-stage filtration and total heat exchange. The filtration system can effectively reduce the indoor particulate matter concentration, and the total heat exchanger 9 can reduce the air conditioning system load. The components adopt standardized interface design, which is convenient for maintenance and replacement. The overall structure takes into account the installation convenience and operation reliability, and can meet the conventional use requirements.

[0125] In another technical solution, further, the housing member comprises:

[0126] The outer shell 11 is used to embed into a window or a wall;

[0127] The inner shell 13 is arranged inside the outer shell 11, and is used to fix the outdoor fresh air fan 1, the switching valve, the indoor air supply fan 6, the oxygen-enriching membrane device 8, the air pump 7, the indoor return air fan 5, the gas monitoring unit and the control unit 4, and the outdoor exhaust fan 10;

[0128] A sound insulation wool layer 12 is filled between the outer shell 11 and the inner shell 13.

[0129] The outer shell 11 can be made of a galvanized steel plate or an aluminum alloy plate with a thickness of 1.0 to 1.5 mm, and the surface can be treated with plastic spraying. The color can be white or light gray. The size of the outer shell 11 can be determined according to the installation space, and the common specifications include a length of 800 to 1200 mm, a width of 400 to 600 mm, and a thickness of 200 to 300 mm. The outer shell 11 can be provided with a mounting flange around the periphery, the flange has a width of 20 to 30 mm, and a mounting hole with a diameter of 6 mm is formed on the flange, and the hole distance is 150 to 200 mm. The inner shell 13 can be made of an aluminum alloy plate with a thickness of 0.8 to 1.2 mm, and the inner shell 13 is fixed and installed by welding or riveting inside. The mounting bracket can adopt an L-shaped or U-shaped structure, and the material thickness is 1.5 to 2.0 mm. The inner shell 13 and the outer shell maintain a spacing of 20 to 30 mm, and this space is used to fill sound insulation materials. The surface of the inner shell 13 can be treated by anodic oxidation to improve corrosion resistance. The sound insulation wool layer 12 can be made of glass wool or rock wool material with a density of 32 to 48 kg / m 3 , and a thickness of 20 to 30 mm. The sound insulation wool can be processed into blocks or plates and filled in the cavity between the outer shell 11 and the inner shell 13. When filling, it should be ensured that the sound insulation material is evenly distributed and no gap is left, and the overcompaction effect on the sound insulation effect is avoided.

[0130] When assembling, the inner shell 13 is first fixed in place, and then the sound insulation wool is filled in the cavity between the outer shell 11 and the inner shell 13. During the filling process, attention should be paid to maintaining the fluffiness of the sound insulation wool, and the compression rate is controlled between 15% and 25%. After filling is completed, the outer shell 11 is installed, and self-tapping screws are used to fix at an interval of 150 to 200 mm. The length of the screw can be selected as 16 to 20 mm, and the tightening torque is controlled in the range of 1.5 to 2.5 newton meters.

[0131] During system operation, the vibration generated by the equipment is transmitted to the sound insulation wool layer 12 through the inner shell 13. The sound insulation wool absorbs sound wave energy through its porous structure and converts mechanical vibration into heat energy. At the same time, the air layer between the outer shell 11 and the inner shell 13 also plays a sound insulation role. Such a double-layer structure cooperates with the filling of sound insulation wool to effectively reduce the transmission of noise.

[0132] The shell structure provides installation and fixing functions through the outer shell 11, the inner shell 13 bears the weight of the equipment, and the sound insulation wool layer 12 absorbs the running noise, realizing the balance of strength and noise reduction. This design effectively controls the system running noise, while ensuring the structural strength and installation stability. The selection of materials and assembly methods of each component considers the service life and maintenance convenience, which can meet the requirements of the conventional use environment.

[0133] In another technical solution, further, when the oxygen concentration is lower than the preset target oxygen concentration, the control unit controls the switching valve to open the oxygen-enriched membrane device 8 path, and starts or increases the power of the air pump 7 to make the air flow through the oxygen-enriched membrane device 8 to generate oxygen-enriched air. When the oxygen concentration is greater than or equal to 26.5% or the carbon dioxide concentration exceeds the preset limit, the control unit controls the switching valve to the bypass air path, that is, to make the inlet thereof communicate with the first outlet, and reduces the power of the air pump 7 or turns it off to make the air enter the indoor through the bypass air path.

[0134] The oxygen-enriched membrane device 8 adopts a high polymer membrane 804, the oxygen permeation amount of the high polymer membrane 804 is 4 , and the oxygen-nitrogen separation coefficient is 2.1.

[0135] In the embodiment, the control unit executes a grading adjustment strategy according to the oxygen concentration monitoring value. When the oxygen concentration is lower than the preset target, the control unit guides the switching valve to the oxygen-enriched membrane device 8 path, and starts or increases the power of the air pump 7 through the frequency converter. When the oxygen concentration reaches 26.5% or the carbon dioxide concentration exceeds 1000 ppm, the control unit switches the switching valve to the bypass air path, and reduces the power of the air pump 7 or turns it off. In specific implementation, the control unit collects sensor data once per second, and eliminates transient fluctuations through digital filtering. When the oxygen concentration is continuously lower than the target value for 5 s, the system starts to start the oxygen-enriched program. The switching valve adopts a slow-moving design, and the valve core needs 2 s to move the full stroke to avoid sudden changes in air flow. The power of the air pump 7 adopts a gradual slope adjustment, and it takes about 3 s to smoothly transition from static to rated power to ensure smooth switching of the system. The oxygen-enriched membrane assembly adopts a hollow fiber structure, the fiber bundle is uniformly distributed in the membrane shell to ensure uniform air flow, and the membrane material is surface-treated to have stable separation performance and long service life.

[0136] In another technical solution, further, the control unit is configured to receive scene mode instructions (including sleep mode, learning mode and sports mode) sent by a user through a remote terminal or a control panel, and the control unit pre-stores a target oxygen concentration range and air volume parameter mapping table corresponding to the scene mode in advance;

[0137] The target oxygen concentration range corresponding to the sleep mode is 21.0% to 22.0%, and the combined operation air volume of the outdoor fresh air fan 1 and the indoor return air fan 5 is controlled to be 80 m 3 / h to 120 m 3 / h;

[0138] The target oxygen concentration range corresponding to the learning mode is 22.5% to 23.5%, and the combined operation air volume is controlled to be 150 m 3 / h to 200 m 3 / h; ​

[0139] The target oxygen concentration range corresponding to the exercise mode is 24.0% to 25.5%, and the combined running air volume is controlled at 220 m 3 / h to 300 m 3 / h.

[0140] The control unit is configured to, after receiving the user-selected scene mode instruction, call the corresponding mapping table, set the target oxygen concentration of the system to the range corresponding to the selected mode, and adjust the combined running air volume to the air volume range corresponding to the selected mode.

[0141] When the system is running in any scene mode, the control unit continuously compares the real-time oxygen concentration measured by the oxygen sensor with the target oxygen concentration range of the current mode.

[0142] When the real-time oxygen concentration continuously falls below the lower limit value of the current target oxygen concentration range for a first preset duration (30 s to 90 s), the control unit controls the switching valve and starts or increases the power of the air pump 7 to increase the supply of oxygen-enriched air.

[0143] When the real-time oxygen concentration continuously rises above the upper limit value of the current target oxygen concentration range for a second preset duration (20 s to 60 s), the control unit controls the switching valve to switch to the bypass air path, and reduces the power of the air pump 7 or turns off the air pump 7.

[0144] In the prior art, conventional indoor environment control systems usually run with fixed parameters, regardless of whether the user is in a sleep, learning or exercise state, the system maintains a uniform oxygen concentration and ventilation volume setting. This approach is difficult to adapt to the differences in oxygen demand and ventilation perception of the human body in different activity states. During sleep, the excessive air volume may affect the quality of rest, and during exercise, the insufficient oxygen concentration may not meet the body's metabolic needs. Users need to manually adjust the parameters frequently, which is not only inconvenient but also difficult to accurately match the actual physiological needs.

[0145] In the present embodiment, the control unit pre-stores parameter combinations for three scene modes. The sleep mode corresponds to an oxygen concentration of 21.0% to 22.0% and a combined air volume of 80 to 120 m 3 / h; the learning mode corresponds to an oxygen concentration of 22.5% to 23.5% and an air volume of 150 to 200 m 3 / h; and the exercise mode corresponds to an oxygen concentration of 24.0% to 25.5% and an air volume of 220 to 300 m 3The user selects the required mode through the mobile terminal or the wall-mounted panel, and the control unit automatically calls the corresponding oxygen concentration range and air volume value as the system set point. The system continuously monitors the actual oxygen concentration, and when the concentration is continuously lower than the lower limit of the current mode for 30 to 90 seconds, the oxygen enrichment program is automatically started, the switching valve is guided to the oxygen enrichment membrane device 8 path, and the air pump 7 power is increased; when the concentration is continuously higher than the upper limit of the current mode for 20 to 60 seconds, the bypass air path is switched to and the air pump 7 output is reduced.

[0146] The technical solution realizes automatic switching of the control strategy through scene recognition, so that the system can recognize the user's activity intention through software logic expansion without changing the hardware structure. The system establishes a differentiated parameter combination according to the physiological characteristics of low metabolic rate during sleep and high oxygen consumption during exercise, which avoids the inadaptability of the fixed parameter system and reduces the tediousness of manual adjustment by the user. Tests show that this method improves the matching degree of environmental parameters and the actual state of the human body while maintaining stable operation of the system.

[0147] In another technical solution, further, the gas monitoring unit and the control unit 4 further include an indoor temperature and humidity sensor, a formaldehyde sensor, a PM2.5 sensor, a TVOC sensor, and a carbon monoxide sensor.

[0148] The control unit is configured to perform the following control logic:

[0149] First, it is determined whether the real-time concentration measured by the carbon monoxide sensor exceeds its corresponding threshold value of 10 ppm;

[0150] If it exceeds, the control unit ignores the current oxygen concentration value and forces the system to switch to the high-speed ventilation mode (the switching valve switches to the bypass air path, the air pump 7 is turned off, and the combined air volume of fresh air and return air is increased to 90%-100% of the maximum air volume of the system);

[0151] If it does not exceed, the control unit sequentially determines whether at least one of the formaldehyde concentration, the TVOC concentration, and the PM2.5 concentration exceeds its corresponding threshold value; if any of the pollutant concentrations exceeds the threshold value, the control unit increases the combined operation air volume of the outdoor fresh air fan 1 and the indoor return air fan 5 while maintaining the current oxygen concentration control target, and the increase amplitude is positively correlated with the type and the exceeding amplitude of the exceeding pollutant; the formaldehyde threshold value is 0.08 mg / m 3 , the TVOC threshold value is 0.6 mg / m 3 , and the PM2.5 threshold value is 35 μg / m 3 .

[0152] If all the pollutant concentrations are not over the standard, and the indoor temperature measured by the temperature and humidity sensor is lower than 18℃ or higher than 28℃, or the indoor relative humidity is lower than 40% or higher than 70%, the control unit adjusts the fan speed of the total heat exchanger 9 or sends a control signal to the building central air conditioning system to coordinate the temperature and humidity adjustment while maintaining the current oxygen concentration control target.

[0153] In the prior art, the traditional indoor environment control system often handles multiple environmental parameters in parallel. When multiple sensors detect abnormalities at the same time, the system may execute multiple adjustment instructions at the same time, leading to control logic conflicts. For example, when increasing ventilation to dilute pollutants, the large amount of fresh air introduced may reduce the indoor oxygen concentration, making it difficult to achieve the oxygen enrichment control target, and the system has difficulty in coordinating the priority between different control targets.

[0154] In the present embodiment, the gas monitoring unit adds indoor temperature and humidity, formaldehyde, PM2.5, TVOC, and carbon monoxide sensors. The control unit establishes a serial judgment logic based on safety priority. The system first judges whether the carbon monoxide concentration exceeds the safety threshold of 10 ppm. If it exceeds the standard, it ignores the current oxygen concentration value and forcibly switches the system to high-speed ventilation mode (switching valve bypass, closing air pump 7, and increasing fan air volume to 90%-100%) to prioritize the removal of toxic gases. If the carbon monoxide concentration does not exceed the standard, it sequentially judges whether the formaldehyde, TVOC, and PM2.5 concentrations exceed their corresponding thresholds. If any pollutant concentration exceeds the standard, it increases the combined air volume while maintaining the current oxygen concentration control target. If all pollutants are within the standard but the temperature and humidity are not suitable, it adjusts the total heat exchanger 9 or coordinates with the building central air conditioning system for temperature and humidity adjustment.

[0155] The present technical solution establishes a hierarchical condition judgment logic, which sequentially integrates multiple sensor data into a single execution instruction. By setting carbon monoxide as the highest priority, the system's rapid response capability in emergency situations is ensured. Other pollutants and comfort parameters are controlled in coordination, without affecting the stability of the core oxygen enrichment function when solving non-core environmental problems. This method avoids the instruction conflict of multi-target control through a serial processing mechanism, ensuring the uniqueness of the system's decision and the safety of its operation under complex working conditions.

[0156] In another technical solution, further, the control unit has pre-stored mapping relationships between the reference concentration thresholds of at least three pollutants and the air volume adjustment coefficients, including formaldehyde, TVOC, and PM2.5.

[0157] The control unit is configured to execute the following air volume coordination control strategy when it is determined that any pollutant concentration exceeds the standard:

[0158] Firstly, the exceeding multiple of the current exceeding pollutant is calculated, and the exceeding multiple is the real-time concentration value of the pollutant divided by the corresponding reference concentration threshold value;

[0159] Secondly, according to the type of the exceeding pollutant, the corresponding air volume adjustment coefficient (formaldehyde 1.5-2.0, TVOC 1.2-1.6, PM2.5 1.0-1.4) is obtained from the mapping relationship;

[0160] Then, the exceeding multiple is multiplied by the corresponding air volume adjustment coefficient to obtain the theoretical air volume improvement ratio of the pollutant;

[0161] If multiple pollutants exceed at the same time, the maximum value of all theoretical air volume improvement ratios is taken as the final air volume improvement ratio;

[0162] Finally, according to the final air volume improvement ratio, the joint operation air volume of the outdoor fresh air fan 1 and the indoor return air fan 5 is improved under the premise of maintaining the current oxygen concentration control target, and the improved joint operation air volume should not exceed 70% of the system rated maximum air volume (the system rated maximum air volume is the sum of the maximum design air volume of the outdoor fresh air fan 1 and the indoor return air fan 5);

[0163] In this process, the control unit continuously monitors the change of oxygen concentration, and if the oxygen concentration deviates from the current target range due to air volume improvement, the air volume improvement operation is preferentially maintained, and the air pump 7 is started at the same time to compensate for the deviation of oxygen concentration.

[0164] In the prior art, when the indoor environmental system detects that multiple pollutants exceed, it usually only dilutes by simply increasing the ventilation, but this single means often leads to large fluctuations in indoor oxygen concentration: different pollutants have different characteristics, and a unified air volume improvement strategy may cause energy waste or poor treatment effect, and lacks a compensation mechanism for the influence of oxygen concentration, making it difficult to balance between pollutant removal and oxygen concentration stability.

[0165] In the present embodiment, the control unit establishes a quantitative adjustment model of pollutant types and exceeding amplitude. When the system detects that formaldehyde, TVOC or PM2.5 exceeds, firstly, the exceeding multiple of each pollutant (real-time concentration / threshold value) is calculated. Then, according to the type of the pollutant, the corresponding air volume adjustment coefficient (formaldehyde 1.5-2.0, TVOC 1.2-1.6, PM2.5 1.0-1.4) is selected. The exceeding multiple is multiplied by the adjustment coefficient to obtain the theoretical air volume improvement ratio, and if multiple pollutants exceed at the same time, the maximum value is taken as the final improvement. After joint air volume improvement, it is limited within 70% of the rated maximum air volume, and in this process, the change of oxygen concentration is continuously monitored, and if it deviates, the air pump 7 is started for compensation.

[0166] The present application ensures that the air volume increase range matches the pollution level through quantitative calculation, and controls the upper limit of air volume increase at 70%, which ensures the dilution effect of pollutants and avoids excessive ventilation to increase energy consumption. At the same time, the synchronous oxygen concentration monitoring and compensation mechanism is introduced, so that the system can maintain stable oxygen concentration while removing pollutants, achieving dynamic balance of multi-objective control. Compared with the traditional simple air volume increase mode, the fine adjustment strategy significantly improves the adaptability of the system under complex pollution conditions.

[0167] In another technical solution, further, the switching valve is an adjustable damper for controlling the proportion of air flowing through the oxygen-enriching membrane device 8;

[0168] The control unit is configured to perform the following oxygen concentration deviation compensation mechanism when performing air volume increase to handle pollutant over-standard:

[0169] First, the control unit calculates the deviation value of the current oxygen concentration from the lower limit value of the target oxygen concentration range in real time. When the deviation value reaches-2.0 percentage points, the control unit starts the first-level compensation strategy (starts the air pump 7 and adjusts the negative pressure to 60-70 kPa);

[0170] If the deviation value does not narrow to within-1.0 percentage points within 10 s after the first-level compensation strategy is performed, the control unit starts the second-level compensation strategy (increases the negative pressure of the air pump 7 to 71-81 kPa, and adjusts the damper to increase the proportion of air flowing through the oxygen-enriching membrane device 8 by 20%-40%);

[0171] The control unit keeps the combined operation air volume increased due to handling of pollutant over-standard unchanged during the execution of the compensation strategy;

[0172] If the deviation value continues to expand to-3.0 percentage points and maintains for 5 s to 15 s, the control unit determines that the compensation fails, and performs a safety intervention measure (gradually reduces the combined air volume until the oxygen concentration returns to the target range);

[0173] The control unit records the duration and compensation effect of each compensation operation, and dynamically adjusts the threshold and parameters according to the historical data to optimize the compensation effect.

[0174] In the prior art, when the system increases ventilation to handle pollutant over-standard, a large amount of fresh air introduced will dilute the indoor oxygen concentration, causing the oxygen concentration to drop rapidly. The conventional system often relies only on simple start-stop air pump 7 to increase oxygen production for compensation, but the response speed is limited and the adjustment capacity is insufficient, making it difficult to effectively stabilize the oxygen concentration under high ventilation, and often resulting in compensation lag or insufficient force.

[0175] In the present embodiment, the system adopts a hierarchical compensation mechanism to address this problem. The control unit calculates the deviation of the current oxygen concentration from the lower limit of the target range in real time: when the deviation reaches -2.0 percentage points, the first-level compensation strategy is started (the air pump 7 is immediately started and the negative pressure is adjusted to 60-70 kPa); if the deviation fails to narrow to within -1.0 percentage points within 10 s after the first-level compensation is performed, the second-level compensation strategy is started (the negative pressure of the air pump 7 is increased to 71-81 kPa, and the damper is adjusted to increase the oxygen-enriched membrane air flow by 20%-40%). During the entire compensation process, the system maintains the joint operation air flow increased due to the treatment of pollutants. If the deviation continues to expand to -3.0 percentage points and is maintained for 5-15 s, it is determined that the compensation has failed, and the safety intervention measure is performed to gradually reduce the joint operation air flow until the oxygen concentration returns to the target range.

[0176] The present application establishes a hierarchical mechanism for dynamically combining adjustment means according to the deviation degree, enhances the rapid response and oxygen-enriched compensation ability of the system under complex working conditions through the synergistic effect of air pump 7 power regulation and air flow distribution adjustment, while adhering to the priority of pollutant removal, the targeted compensation measures effectively offset the negative impact of fresh air dilution on oxygen concentration, achieving dynamic balance and adaptive optimization of multi-objective control, and greatly improving the reliability of system operation.

[0177] In another technical solution, further, the system further comprises an outdoor temperature and humidity sensor for measuring outdoor temperature and relative humidity;

[0178] The control unit adjusts the operating state of the total heat exchanger 9 or adjusts the air flow under the premise of maintaining the current oxygen concentration control target to coordinate the process of temperature and humidity regulation of the building central air conditioning system, and the specific process includes:

[0179] The control unit is configured to perform the following temperature and humidity coordination control logic:

[0180] First, the indoor temperature value and the indoor relative humidity value measured by the temperature and humidity sensor are monitored in real time; if the indoor temperature value is below 18 ℃ or above 28 ℃ for a duration of a third preset time length (5 min to 15 min), or the indoor relative humidity value is below 40% or above 70% for a duration of a third preset time length, the control unit starts a temperature and humidity regulation mode under the premise of maintaining the current oxygen concentration control target;

[0181] The temperature and humidity regulation mode includes: when the temperature needs to be adjusted, the indoor temperature value is compared with the outdoor temperature value; if the indoor temperature value is higher than the outdoor temperature value, the joint operation air flow of the outdoor fresh air fan 1 and the indoor return air fan 5 is preferentially increased, and the joint operation air flow is adjusted in a positive direction within the range of 0% to +30% of the system rated air flow to introduce more low-temperature outdoor air for cooling;

[0182] If the indoor temperature value is lower than the outdoor, the fan speed of the total heat exchanger 9 is preferentially adjusted, linearly adjusted within the range of 50% to 100% of the rated speed, the heat recovery efficiency is improved, and the heat loss is reduced;

[0183] When the humidity needs to be adjusted, the indoor and outdoor humidity is compared: if the indoor humidity is higher than the outdoor, the combined air volume of fresh air and return air is preferentially increased, positively adjusted within the range of 0% to +25% of the rated air volume of the system, and dry outdoor air is introduced for dehumidification; if the indoor humidity is lower than the outdoor, the fan speed of the total heat exchanger 9 is preferentially adjusted, linearly adjusted within the range of 60% to 100% of the rated speed, and the humidity exchange is enhanced to maintain the indoor humidity.

[0184] When the temperature and humidity adjustment mode is executed, the control unit continuously monitors the oxygen concentration: if the real-time oxygen concentration is continuously lower than the lower limit of the current target range or higher than the upper limit due to adjustment operation for 10 seconds, the current temperature and humidity adjustment is immediately terminated, and the fan speed of the total heat exchanger 9 and the combined air volume of fresh air / return air are restored to the set values before adjustment.

[0185] In the prior art, the conventional temperature and humidity adjustment system often only adjusts in one direction according to the deviation of the indoor set value and the measured value, and lacks consideration of the outdoor environmental conditions. This may lead to the introduction of higher temperature outdoor air when cooling is needed, or excessive ventilation causing heat loss when heat preservation is needed, which not only fails to improve comfort, but also may exacerbate energy consumption, and conflicts with the building air conditioning system.

[0186] In the present embodiment, an outdoor temperature and humidity sensor is added, and a directional adjustment strategy based on physical laws is established. When the indoor temperature is continuously lower than 18 ℃ or higher than 28 ℃ for 5-15 min, or the humidity deviates from the range of 40% to 70% for 5-15 min, the system starts the temperature and humidity adjustment mode. When the temperature needs to be adjusted, the control unit first compares the indoor and outdoor temperature values: if the indoor temperature is higher than the outdoor, the combined air volume of fresh air and return air is preferentially increased, and the low-temperature outdoor air is introduced for cooling, and the increase is controlled within 30% of the rated air volume of the system; if the indoor temperature is lower than the outdoor, the fan speed of the total heat exchanger 9 is preferentially adjusted to the range of 50% to 100% of the rated speed, the heat recovery efficiency is improved, and the heat loss is reduced. When the humidity needs to be adjusted, the indoor and outdoor humidity values are also compared: if the indoor humidity is too high and the outdoor is drier, the combined air volume is increased to introduce dry air, and the increase is not more than 25% of the rated air volume; if the indoor humidity is too low and the outdoor is more humid, the fan speed of the total heat exchanger 9 is adjusted to the range of 60% to 100% of the rated speed, and the humidity exchange is enhanced to maintain the indoor humidity.

[0187] The scheme compares indoor and outdoor environmental parameters in real time, establishes a directional adjustment logic based on thermodynamic laws, ensures that each temperature and humidity intervention is based on a comprehensive judgment of indoor and outdoor conditions, and avoids the deviation of adjustment measures from actual needs. While maintaining the control of oxygen concentration as the core goal, the system achieves energy efficiency coordination with the building central air conditioning system, improving the rationality and economy of environmental regulation.

[0188] A control method of a local space oxygen-enriched control system based on an oxygen-selective permeation membrane, as shown in Figure 4 The method comprises the following steps:

[0189] Real-time monitoring of indoor oxygen concentration and carbon dioxide concentration by a gas monitoring unit;

[0190] The control unit compares the monitored oxygen concentration with the preset target oxygen concentration (21% to 26%);

[0191] When the monitored oxygen concentration is lower than the preset target oxygen concentration, the control unit switches the valve to the oxygen-enriched membrane device 8 path and starts the air pump 7, and adjusts the air volume of the outdoor fresh air fan 1, the indoor return air fan 5, the indoor supply air fan 6, and the outdoor exhaust air fan 10;

[0192] The air pump 7 applies a negative pressure (-60 kPa to -81 kPa) at the oxygen outlet 802 of the oxygen-enriched membrane device 8, the oxygen-enriched membrane device 8 separates oxygen-enriched air from air, and the oxygen-enriched air is sent into the indoor supply air fan 6 and into the indoor through the air pump 7;

[0193] When the monitored oxygen concentration is ≥26.5% or the carbon dioxide concentration exceeds the preset limit, the control unit controls the switching valve to switch to the bypass air path, reduces the negative pressure of the air pump 7 or closes it, so that air enters the indoor directly through the bypass air path;

[0194] Real-time monitoring of indoor temperature, indoor relative humidity, carbon monoxide concentration, formaldehyde concentration, TVOC concentration, and PM2.5 concentration by the gas monitoring unit;

[0195] When the carbon monoxide concentration exceeds its preset threshold, the control unit ignores the current oxygen concentration value, forcibly controls the switching valve to switch to the bypass air path, closes the air pump 7, and increases the combined air volume of fresh air / return air to 90%-100% of the system rated maximum air volume;

[0196] When the carbon monoxide concentration does not exceed its preset threshold, but any one of formaldehyde, TVOC, or PM2.5 concentration exceeds the standard, while maintaining the current oxygen concentration control target, the control unit determines the final air volume increase ratio according to the type and excess of the exceeding pollutant, and increases the combined air volume of fresh air / return air (upper limit is 70% of the system rated maximum air volume);

[0197] When all the pollutant concentrations are not over the standard, and the indoor temperature or humidity is out of the range of 18-28 ℃ or 40%-70% for 5-15 min continuously, the control unit starts the temperature and humidity adjustment mode to adjust the operation of the total heat exchanger 9 or the air volume to coordinate the central air conditioning system to adjust the temperature and humidity on the premise of maintaining the current oxygen concentration control target.

[0198] In the prior art, the conventional indoor environment control method often runs the oxygen concentration adjustment, pollutant removal and temperature and humidity control as independent control loops in parallel. When multiple environmental parameters are abnormal at the same time, the system may issue contradictory control instructions: for example, while increasing the ventilation volume to remove pollutants, the oxygen concentration is lowered and the oxygen generation function is started, causing the system to repeatedly oscillate between multiple control targets, making it difficult to form a unified and coordinated control strategy.

[0199] The present embodiment establishes a serial execution process based on safety priority. The system first collects oxygen and carbon dioxide concentration data: when the oxygen concentration is lower than 21%, the switching valve connects the oxygen-enriched membrane device 8 path and starts the air pump 7 (maintaining 60-81 kPa negative pressure on the membrane side); when the oxygen concentration reaches 26.5% or the carbon dioxide exceeds 1000 ppm, the system switches to the bypass air path and reduces the air pump 7 output. On this basis, the system continuously monitors the carbon monoxide concentration and immediately forces the bypass, closes the air pump 7 and increases the combined air volume to 90%-100% as soon as it exceeds 10 ppm. For formaldehyde, TVOC or PM2.5 over standard, the required air volume increase ratio is calculated but the upper limit is controlled at 70%. Only when all pollution indicators are normal, the temperature and humidity adjustment based on indoor and outdoor comparison is started on the premise of maintaining the oxygen concentration.

[0200] The method of the present application ensures the orderliness of the system's decision-making in complex multi-parameter environments through the serial logic of placing acute safety threats at the highest priority, followed by chronic health effects, and finally dealing with comfort. When executing non-core target adjustment, the oxygen concentration is always stabilized as a prerequisite, and the core target is maintained unchanged through a parallel compensation mechanism. This method achieves a transition from single-parameter independent control to multi-target coordinated control by unifying and coordinating multiple control loops, improving the overall stability of the system under complex working conditions.

[0201] In a 20 L closed simulation box (room temperature 24-26 ℃, relative humidity 40%-65%, membrane module area 7×100 cm²), the total flow rate is set to 1.5 L / min, and the membrane permeation side negative pressure is about -70 kPa. The oxygen concentration rises from 21.2% to 26.1% within 3 to 35 min and stabilizes in a fluctuation range of ±0.1% (as shown in Figure 5 This shows that the method of the present application has the characteristics of rapid response, high control precision and good steady-state performance, verifying the effectiveness and feasibility of its technical principles and control strategies.

[0202] While embodiments of the application have been disclosed in connection with the above specification and drawings this description is not intended to limit the scope of the application and many modifications, enhancements, alternatives, and variations will become apparent to those skilled in the art from this disclosure. Accordingly, it is expressly intended that the description should not limit the application as claimed but rather the only limitation placed on the scope of the application be the scope of the claims as set out below and equivalents thereof.

Claims

1. A localized space oxygen enrichment control system based on oxygen-selective permeation membranes, characterized in that, The system comprises: An outdoor fresh air fan, the outlet of which is connected to the inlet of a switching valve, the switching valve comprising a first outlet and a second outlet; An indoor air supply fan, the inlet of which is connected to the first outlet of the switching valve to form a bypass air path, the outlet of the indoor air supply fan leading to the indoor space; An oxygen-enriched membrane device, the inlet of which is connected to the second outlet of the switching valve, the oxygen-enriched membrane device being provided with an oxygen outlet and a waste gas outlet; A gas pump, the inlet of which is connected to the oxygen outlet of the oxygen-enriched membrane device, and the outlet of which is connected to the inlet of the indoor air supply fan; An indoor return air fan, the inlet of which leads to the indoor space; A gas monitoring unit and a control unit, the inlet of which is connected to the outlet of the indoor return air fan, the gas monitoring unit and the control unit comprising an oxygen sensor and a carbon dioxide sensor; An outdoor exhaust fan, the inlet of which is connected to the outlet of the gas monitoring unit and the control unit and the waste gas outlet of the oxygen-enriched membrane device through pipelines, and the outlet of which leads to the outdoor space; A housing member for wrapping and fixing the outdoor fresh air fan, the switching valve, the indoor air supply fan, the oxygen-enriched membrane device, the gas pump, the indoor return air fan, the gas monitoring unit and the control unit, and the outdoor exhaust fan; The control unit is configured to control the position of the switching valve according to the difference between the oxygen concentration measured by the oxygen sensor and the preset target oxygen concentration, and whether the concentration measured by the carbon dioxide sensor exceeds the preset limit value, and to adjust the rotation speed of the outdoor fresh air fan, the indoor return air fan, the indoor air supply fan, and the outdoor exhaust fan through a frequency converter to control the air volume, and to control the start and stop of the gas pump; the preset target oxygen concentration is 21% to 26%, and the preset limit value of the carbon dioxide concentration is 1000 ppm; Further comprising a filtering structure comprising a primary filter screen and a HEPA activated carbon composite filter screen, the outlet of the outdoor fresh air fan being connected to the inlet of the primary filter screen, and the outlet of the primary filter screen being connected to the inlet of the HEPA activated carbon composite filter screen; A total heat exchanger, the fresh air inlet of which is connected to the outlet of the HEPA activated carbon composite filter screen, and the fresh air outlet of which is connected to the inlet of the switching valve; The gas monitoring unit and the control unit further comprise an indoor temperature and humidity sensor, a formaldehyde sensor, a PM2.5 sensor, a TVOC sensor, and a carbon monoxide sensor; The control unit is configured to perform the following control logic: Firstly, it is determined whether the real-time concentration measured by the carbon monoxide sensor exceeds the corresponding threshold value of 10 ppm; If it exceeds, the control unit ignores the current oxygen concentration value, and forcibly switches the system to a high-speed ventilation mode, which includes controlling the switching valve to switch to the bypass air path, closing the gas pump, and increasing the combined air volume of the outdoor fresh air fan and the indoor return air fan to 90% to 100% of the maximum air volume of the system; If not, the control unit sequentially determines whether at least one of the formaldehyde concentration, the TVOC concentration, and the PM2.5 concentration exceeds the corresponding threshold value; if any of the pollutant concentrations exceeds the threshold value, the control unit increases the combined operation air volume of the outdoor fresh air fan and the indoor return air fan under the premise of maintaining the current oxygen concentration control target, and the increase amplitude is positively correlated with the type and the exceeding amplitude of the exceeding pollutant; the formaldehyde threshold value is 0.08 mg / m 3 , the TVOC threshold value is 0.6 mg / m 3 , and the PM2.5 threshold value is 35 μg / m 3 . If none of the pollutant concentrations exceeds the standard, and the indoor temperature measured by the temperature and humidity sensor is lower than 18 ℃ or higher than 28 ℃, or the indoor relative humidity is lower than 40% or higher than 70%, the control unit adjusts the fan speed of the total heat exchanger or sends a control signal to the central air conditioning system of the building to cooperatively adjust the temperature and humidity while maintaining the current oxygen concentration control target. The control unit pre-stores a mapping relationship between reference concentration thresholds of at least three pollutants and air volume adjustment coefficients, the pollutants including formaldehyde, TVOC and PM2.5; The control unit is configured to execute the following air volume coordinated control strategy when it is determined that any of the concentrations of the pollutants exceeds the standard: First, the exceeding multiple of the current exceeding pollutant is calculated, the exceeding multiple being the real-time concentration value of the pollutant divided by the corresponding reference concentration threshold; Second, the corresponding air volume adjustment coefficient is obtained from the mapping relationship according to the type of the exceeding pollutant; wherein the air volume adjustment coefficient corresponding to formaldehyde is 1.5 to 2.0, the air volume adjustment coefficient corresponding to TVOC is 1.2 to 1.6, and the air volume adjustment coefficient corresponding to PM2.5 is 1.0 to 1.4; Then, the exceeding multiple is multiplied by the corresponding air volume adjustment coefficient to obtain the theoretical air volume improvement ratio of the pollutant; If multiple pollutants exceed the standard at the same time, the maximum value of all the theoretical air volume improvement ratios is taken as the final air volume improvement ratio; Finally, the joint operation air volume of the outdoor fresh air fan and the indoor return air fan is improved under the premise of maintaining the current oxygen concentration control target, and the improved joint operation air volume should not exceed 70% of the system rated maximum air volume, wherein the system rated maximum air volume is the sum of the maximum design air volumes of the outdoor fresh air fan and the indoor return air fan. The control unit continuously monitors the change of oxygen concentration while improving the air volume to handle the exceeding of the pollutants, and if the oxygen concentration deviates from the current target range due to the improvement of the air volume, the air volume improvement operation is preferentially maintained, and the air pump is started at the same time to compensate for the deviation of the oxygen concentration.

2. The oxygen-selectively permeable membrane based localized space oxygen enrichment control system of claim 1, wherein, The shell member comprises: an outer shell for embedding into a window or wall; an inner shell arranged inside the outer shell for fixing the outdoor fresh air fan, the switching valve, the indoor air supply fan, the oxygen enrichment membrane device, the air pump, the indoor return air fan, the gas monitoring unit, the control unit and the outdoor exhaust air fan; a sound insulation layer filled between the outer shell and the inner shell.

3. The oxygen-selectively permeable membrane based localized space oxygen enrichment control system of claim 1, wherein, When the oxygen concentration is lower than the preset target oxygen concentration, the control unit controls the switching valve to communicate the inlet with the second outlet, and starts or increases the power of the air pump to make the air flow through the oxygen enrichment membrane device to generate oxygen-enriched air; when the oxygen concentration is greater than or equal to 26.5% or the carbon dioxide concentration exceeds the preset limit value, the control unit controls the switching valve to communicate the inlet with the first outlet, and reduces the power of the air pump or turns off the air pump to make the air enter the indoor space through the bypass air path. The oxygen-enriched membrane device adopts a polymer membrane, and the oxygen permeation amount of the polymer membrane is 4 m 3 / (m 2 ▪h▪bar) to 5 m 3 / (m 2 ▪h▪bar), and the oxygen-nitrogen separation coefficient is 2.

1.

4. The local space oxygen enrichment control system based on the oxygen-selective permeation membrane according to claim 1, wherein the control unit is configured to receive scene mode instructions sent by a user through a remote terminal or a control panel, the scene modes include a sleep mode, a study mode and an exercise mode, and the control unit pre-stores a target oxygen concentration range and air volume parameter mapping table corresponding to the scene modes. The control unit is configured to: after receiving the scene mode instruction selected by the user, call the corresponding mapping table, set the target oxygen concentration of the system to the range corresponding to the selected mode, and adjust the joint operation air volume to the air volume range corresponding to the selected mode. The target oxygen concentration range corresponding to the sleep mode is 21.0% to 22.0%, and the combined operation air volume of the outdoor fresh air fan and the indoor return air fan is controlled to be 80 m 3 / h to 120 m 3 / h. The target oxygen concentration range corresponding to the learning mode is 22.5% to 23.5%, and the combined operating air volume is controlled to 150 m 3 / h to 200 m 3 / h; The target oxygen concentration range corresponding to the exercise mode is 24.0% to 25.5%, and the combined operating air volume is controlled at 220 m 3 / h to 300 m 3 / h; ​ When the system is running in any of the scene modes, the control unit continuously compares the real-time oxygen concentration measured by the oxygen sensor with the target oxygen concentration range of the current mode; When the real-time oxygen concentration continuously falls below the lower limit value of the current target oxygen concentration range for a first preset duration, the control unit controls the switching valve to switch to the path where air flows through the oxygen enrichment membrane device, and starts or increases the power of the air pump to increase the supply of oxygen-enriched air; When the real-time oxygen concentration continuously rises above the upper limit value of the current target oxygen concentration range for a second preset duration, the control unit controls the switching valve to switch to the bypass air path, and reduces the power of the air pump or turns it off; The first preset duration is 30 s to 90 s, and the second preset duration is 20 s to 60 s.

5. The oxygen-selectively permeable membrane based localized space oxygen enrichment control system of claim 1, wherein, The switching valve is an adjustable damper for controlling the proportion of air flowing through the oxygen enrichment membrane device; The control unit is configured to perform the following oxygen concentration deviation compensation mechanism when executing air volume increase to handle pollutant over-standard: First, the control unit calculates the deviation value of the current oxygen concentration from the lower limit value of the target oxygen concentration range in real time. When the deviation value reaches -2.0 percentage points, the control unit starts the first-level compensation strategy, which includes starting the air pump and adjusting the negative pressure of the air pump to the range of -60 KPa to -70 KPa; If the deviation value does not narrow to within -1.0 percentage points within 10 s after executing the first-level compensation strategy, the control unit starts the second-level compensation strategy, which includes increasing the negative pressure of the air pump to the range of -71 KPa to -81 KPa, and increasing the proportion of air flowing through the oxygen enrichment membrane device by 20% to 40% by adjusting the damper; The control unit maintains the increased combined operation air volume for handling pollutant over-standard during the execution of the compensation strategy; If the deviation value continuously expands to -3.0 percentage points and maintains for 5 s to 15 s, the control unit determines that the compensation has failed, and executes a safety intervention measure, which includes gradually reducing the combined operation air volume until the oxygen concentration returns to the target range; The control unit records the duration and compensation effect of each compensation operation, and enables the control unit to dynamically adjust the starting threshold and parameters based on historical compensation data to optimize the compensation effect.

6. The oxygen-selectively permeable membrane-based localized, spatially- controlled oxygen enrichment system of claim 1, wherein, An outdoor temperature and humidity sensor is also included for measuring outdoor temperature and relative humidity; The control unit adjusts the operating state of the total heat exchanger or adjusts the air volume to coordinate the specific process of temperature and humidity regulation of the building central air conditioning system while maintaining the current oxygen concentration control target, which includes: The control unit is configured to execute the following temperature and humidity coordination control logic: First, the indoor temperature value and indoor relative humidity value measured by the temperature and humidity sensor are monitored in real time; If the indoor temperature value is below 18 ℃ or above 28 ℃ for a third preset duration, or the indoor relative humidity value is below 40% or above 70% for a third preset duration, the control unit starts the temperature and humidity regulation mode while maintaining the current oxygen concentration control target; The temperature and humidity regulation mode includes the following operations: When temperature adjustment is required, the control unit first compares the indoor temperature with the outdoor temperature. If the indoor temperature is higher than the outdoor temperature, the control unit prioritizes increasing the combined airflow of the outdoor fresh air fan and the indoor return air fan, adjusting it positively within the range of 0% to +30% of the system's rated airflow to introduce more low-temperature outdoor air for cooling. If the indoor temperature is lower than the outdoor temperature, the control unit prioritizes adjusting the fan speed associated with the total heat exchanger, adjusting it linearly within the range of 50% to 100% of the rated speed to improve heat recovery efficiency and reduce indoor heat loss. When humidity needs to be adjusted, the control unit first compares the indoor relative humidity value with the outdoor relative humidity value. If the indoor relative humidity value is higher than the outdoor relative humidity value, the control unit prioritizes increasing the combined operating air volume of the outdoor fresh air fan and the indoor return air fan, adjusting it positively within the range of 0% to +25% of the system's rated air volume to introduce drier outdoor air for dehumidification. If the indoor relative humidity value is lower than the outdoor relative humidity value, the control unit prioritizes adjusting the speed of the internal fan of the total heat exchanger, adjusting it linearly within the range of 60% to 100% of the rated speed to improve humidity exchange efficiency and maintain indoor humidity. When the control unit is executing the temperature and humidity adjustment mode, it continuously compares the real-time oxygen concentration measured by the oxygen sensor with the current target oxygen concentration range. If the real-time oxygen concentration is continuously lower than the lower limit of the current target oxygen concentration range for 10 seconds or continuously higher than the upper limit of the current target oxygen concentration range for 10 seconds due to the temperature and humidity adjustment operation, the control unit immediately terminates the current temperature and humidity adjustment operation and restores the speed of the fan inside the total heat exchanger and the combined operating air volume of the outdoor fresh air fan and the indoor return air fan to the parameter settings before the temperature and humidity adjustment mode was started. The third preset duration is 5 to 15 minutes.

7. A control method of a local space oxygen enrichment control system based on the oxygen-selectively permeable membrane according to any one of claims 1 to 6, characterized by, The method includes the following steps: Indoor oxygen and carbon dioxide concentrations are monitored in real time using a gas monitoring unit. The control unit compares the monitored oxygen concentration with a preset target oxygen concentration, which is 21% to 26%. When the monitored oxygen concentration is lower than the preset target oxygen concentration, the control unit controls the switching valve to switch to the path of air flowing through the oxygen-enriched membrane device, starts the air pump, and adjusts the air volume of the outdoor fresh air fan, indoor return air fan, indoor supply air fan and outdoor exhaust fan. An air pump applies negative pressure at the oxygen outlet of the oxygen-enriched membrane device, with a negative pressure range of -60 kPa to -81 kPa. The oxygen-enriched membrane device separates oxygen-enriched air from the air, and the oxygen-enriched air is sent into the room by the air pump and the indoor air supply fan. When the monitored oxygen concentration is greater than or equal to 26.5% or the carbon dioxide concentration exceeds the preset limit, the control unit controls the switching valve to switch to the bypass ventilation path, reduces the negative pressure of the air pump or shuts it off, so that air can directly enter the room through the bypass ventilation path. The gas monitoring unit monitors indoor temperature, relative humidity, carbon monoxide concentration, formaldehyde concentration, TVOC concentration, and PM2.5 concentration in real time. When the carbon monoxide concentration exceeds its preset threshold, the control unit ignores the current oxygen concentration value, forces the switching valve to switch to the bypass air path, closes the air pump, and increases the combined operation air volume of the outdoor fresh air fan and the indoor return air fan to 90% to 100% of the system rated maximum air volume; When the carbon monoxide concentration does not exceed its preset threshold, but at least one of the formaldehyde concentration, the TVOC concentration, or the PM2.5 concentration exceeds its corresponding threshold, the control unit determines the final air volume increase ratio according to the type and the exceeding amplitude of the exceeding pollutant while maintaining the current oxygen concentration control target, and increases the combined operation air volume of the outdoor fresh air fan and the indoor return air fan, and the increased combined operation air volume shall not exceed 70% of the system rated maximum air volume, wherein the system rated maximum air volume is the sum of the maximum design air volumes of the outdoor fresh air fan and the indoor return air fan; When all pollutant concentrations are not exceeding, and the indoor temperature is continuously outside the range of 18 ℃ to 28 ℃ for 5 min to 15 min, or the indoor relative humidity is continuously outside the range of 40% to 70% for 5 min to 15 min, the control unit starts the temperature and humidity adjustment mode by adjusting the operation state of the total heat exchanger or adjusting the air volume to cooperate with the building central air conditioning system for temperature and humidity adjustment while maintaining the current oxygen concentration control target.

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