Method and system for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen cabin

Abstract

The application provides a micro-pressure oxygen cabin post-use residual oxygen replacement and drying maintenance method and system, and relates to the technical field of micro-pressure oxygen cabins, which comprises a cabin body, an oxygen supply valve, a fresh air inlet valve, an exhaust valve, a fresh air fan, a heating circulating fan, a semiconductor dehumidification module, a photocatalyst catalysis module, an oxygen concentration sensor, a humidity sensor, a pressure sensor and a controller; after use, the cabin pressure is released to 1.02-1.08 atm, the fresh air fan sends filtered and dried fresh air into the cabin through the lower air supply port and discharges the air through the upper air exhaust port, forming a down-sending and up-discharging replacement air flow, the controller maintains the micro-positive pressure according to the pressure feedback, and when the oxygen concentration is reduced to 21%-23%, the valve is closed at a reduced speed within 30-120 seconds, the air in the closed circulation is first condensed and dew dehumidified, then heated to 35-45 C and sent back into the cabin, and the relative humidity is reduced to 40%-50% before the machine is stopped; the application has the advantages of fast residual oxygen replacement, prevention of unfiltered air backflow, complete drying and suitability for the automatic maintenance of the micro-pressure oxygen cabin after use.

Description

Technical Field

[0001] This invention relates to the field of micro-pressure oxygen chamber technology, and in particular to a method and system for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber. Background Technology

[0002] A micro-pressure oxygen chamber is a device that provides oxygen-enriched air to users in a micro-pressure environment of 1.1–1.3 atm. It is widely used in home healthcare, sports recovery, wellness therapy, and medical rehabilitation. After use, the chamber often retains an oxygen concentration higher than atmospheric oxygen. Simultaneously, user sweating and breathing increase the humidity inside the chamber, causing moisture to condense on the walls, seats, observation windows, and seals. If residual oxygen is not replaced and dried promptly, the chamber will remain in a high-oxygen, high-humidity state for extended periods. This poses safety hazards such as organic matter oxidation and combustion, and can also lead to corrosion of metal parts, aging of seals, and the growth of bacteria and mold, shortening the equipment's lifespan.

[0003] In existing technologies, common maintenance methods involve opening the hatch and exhaust vents for natural ventilation after use, or simply using an exhaust fan for ventilation, while drying relies on natural air drying or manual wiping. This method has the following drawbacks: First, the rate of residual oxygen replacement is slow, and the high-oxygen state lasts for a long time; second, during ventilation, unfiltered outside air carrying dust particles and microorganisms directly enters the cabin, causing secondary pollution; third, natural air drying and manual wiping are insufficient to remove moisture adhering to the cabin walls, seats, and seals, resulting in incomplete drying.

[0004] With technological advancements, some micro-pressure oxygen chambers are now equipped with fresh air conditioning systems or closed-loop condensing dehumidifiers. Fresh air conditioning systems replenish the chamber with filtered and temperature- and humidity-controlled fresh air during use, while closed-loop condensing dehumidifiers reduce the moisture content of the circulating air. However, fresh air systems primarily serve air conditioning during use and are not designed for the specific scenario of residual oxygen replacement after use; closed-loop dehumidifiers can only reduce air moisture content, not the oxygen concentration within the chamber. These two systems operate independently, lacking coordinated control for post-use maintenance.

[0005] Simply connecting fresh air replacement with closed-loop dehumidification in series still presents the following specific problems: First, during the replacement phase, both the fresh air intake valve and the exhaust valve need to be opened simultaneously. If the pressure inside the chamber is not controlled in a closed loop, a mismatch between the intake and exhaust airflow can easily lead to negative pressure, causing unfiltered external air to backflow through the gaps in the chamber doors, or causing overpressure that could damage the soft chamber. Second, when transitioning from the replacement phase to the drying phase, if the fresh air fan is stopped and the valve is closed directly, a negative pressure will instantly form inside the chamber, causing backflow and pressure surges. Third, if the airflow organization is improper in the closed-loop circulation, such as heating before condensation or an unreasonable configuration of heating and condensation, not only will the dehumidification energy consumption be high, but the moisture adhering to the chamber walls and sealing surfaces will also be difficult to be effectively carried out by the circulating air, resulting in incomplete drying.

[0006] Therefore, there is a need for a method and system for residual oxygen replacement and drying maintenance of a micro-pressure oxygen chamber after use that can quickly replace residual oxygen, prevent backflow of unfiltered air, ensure thorough drying, and operate automatically. Summary of the Invention

[0007] The purpose of this invention is to provide a method and system for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber, in order to solve the problems of slow residual oxygen replacement, easy secondary pollution caused by opening the chamber for ventilation, easy negative pressure backflow during the replacement and drying process, difficulty in completely removing surface moisture, cumbersome operation, and lack of linkage control in the prior art.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber, comprising the following steps: Step S1: After the use of the micro-pressure oxygen chamber is completed, close the oxygen supply valve, confirm that the chamber door is sealed and closed, and release the pressure inside the chamber to 1.02-1.08 atm through the exhaust valve; Step S2: Open the fresh air intake valve and the exhaust valve, start the fresh air fan, and send the filtered and dried fresh air into the cabin through the air inlet at the bottom of the cabin. The gas in the cabin is discharged through the exhaust valve through the exhaust port at the top of the cabin, forming a bottom-supply and top-exhaust displacement airflow. The controller adjusts the opening of the exhaust valve and / or the speed of the fresh air fan according to the pressure signal collected by the cabin pressure sensor to maintain the cabin pressure at 1.02-1.08 atm, and uses the fresh air to replace the residual oxygen in the cabin. The oxygen concentration in the cabin is monitored in real time by the oxygen concentration sensor. Step S3: When the oxygen concentration sensor detects that the oxygen concentration in the chamber has dropped to 21%–23%, the controller first gradually reduces the speed of the fresh air fan and simultaneously closes the exhaust valve within 30–120 seconds. While maintaining the chamber pressure at 1.02–1.08 atm, the controller closes the fresh air intake valve and the exhaust valve and stops the fresh air fan. Subsequently, the controller starts the heating circulation fan and the dehumidification module, so that the air in the chamber first flows through the condenser side of the dehumidification module to cool down and condense, and then is heated to 35–45°C by the heating circulation fan before being sent back into the chamber, forming a closed loop. The relative humidity in the chamber is monitored in real time by the humidity sensor. Step S4: When the humidity sensor detects that the relative humidity inside the cabin has dropped to 40% to 50%, stop the heating circulation fan and the dehumidification module, and close the fresh air intake valve, the exhaust valve and the oxygen supply valve to complete the residual oxygen replacement and drying maintenance.

[0009] Furthermore, in step S2, the air supply volume of the fresh air fan is 8 to 18 times the internal volume of the micro-pressure oxygen chamber per hour, the internal volume of the micro-pressure oxygen chamber is 0.5 to 5 m³, and the duration of residual oxygen replacement is 4 to 12 min.

[0010] Furthermore, the air supply velocity of the air outlet in step S2 is 0.3 to 1.0 m / s, so that the fresh air forms a piston-like displacement airflow that pushes upward in the cabin.

[0011] Furthermore, in step S2, the controller uses a PID algorithm or a split-range control method to adjust the opening of the exhaust valve and / or the speed of the fresh air fan, and the control accuracy of the cabin pressure is 0.005 atm.

[0012] Furthermore, in step S3, the controller gradually reduces the speed of the fresh air fan according to a linear decreasing curve or a step decreasing curve and simultaneously closes the exhaust valve.

[0013] Furthermore, in step S3, the heating circulating fan heats the air dehumidified by the dehumidification module to 40°C; the dehumidification module is a semiconductor dehumidification module, and the surface temperature of the condenser side of the dehumidification module is 5-15°C. The condensate generated by condensation is discharged to the outside of the cabin through the water collection pan and the water seal pipe.

[0014] Furthermore, the fresh air introduced in step S2 passes sequentially through a HEPA filter, an activated carbon filter, a condenser dryer, and a photocatalytic module. After being dried by the condenser dryer to a relative humidity of less than 40%, it is then catalyzed and disinfected by the photocatalytic module before entering the cabin.

[0015] Furthermore, in step S4, after the relative humidity inside the chamber drops to 40%–50%, the heating circulating fan and the dehumidification module continue to run for 1–5 minutes before stopping; during the closed-loop process in step S3 or after step S4 is completed, an ozone-free ultraviolet germicidal lamp with a radiation wavelength of 253.7 nm is activated to irradiate the chamber for 10–20 minutes; after step S4, the controller records the start and end times of this maintenance, the final oxygen concentration, and the final humidity data, and uploads them to a remote server via the communication module.

[0016] Secondly, this invention provides a residual oxygen replacement and drying maintenance system for a micro-pressure oxygen chamber after use, comprising a chamber body, an oxygen supply valve, a fresh air inlet valve, an exhaust valve, a fresh air fan, a HEPA filter, an activated carbon filter, a condenser dryer, a photocatalytic module, an air supply outlet, an exhaust outlet, a heating and circulating fan, a dehumidification module, an oxygen concentration sensor, a humidity sensor, a pressure sensor, a controller, a communication module, an ozone-free ultraviolet germicidal lamp, and a remote server; the oxygen concentration sensor is an electrochemical oxygen sensor, the humidity sensor is a capacitive humidity sensor, and the pressure sensor is a piezoresistive pressure sensor; the inlet of the fresh air fan is sequentially connected to the HEPA filter and the activated carbon filter, and the outlet of the fresh air fan is connected to the air supply outlet at the bottom of the chamber body via the condenser dryer, the photocatalytic module, and the fresh air inlet valve. The exhaust valve is connected to the exhaust port on the upper part of the cabin; the dehumidification module and the heating circulating fan are connected in series in the closed-loop air circulation path between the circulating return air port and the air supply port of the cabin, and the condenser side of the dehumidification module is located upstream of the air inlet of the heating side of the heating circulating fan. A water collection tray is provided below the condenser side, and the water collection tray is connected to the outside of the cabin through a water seal pipe; the oxygen concentration sensor, the humidity sensor, the pressure sensor and the ultraviolet germicidal lamp are all electrically connected to the controller; the fresh air fan, the heating circulating fan, the dehumidification module, the fresh air inlet valve, the exhaust valve and the oxygen supply valve are all controlled by the controller; the controller is configured to execute the above method and is configured to record the start and end time of maintenance, the final oxygen concentration and the final humidity data and upload them to the remote server through the communication module.

[0017] Furthermore, the dehumidification module is a semiconductor dehumidification module, the condensation side is the cold end heat dissipation fins of the semiconductor cooling chip, and the heating side of the heating circulating fan is the hot end heat dissipation fins of the semiconductor cooling chip or an independent electric heater.

[0018] This invention provides a method and system for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber, which has the following beneficial effects: 1. Thorough and efficient drying: In the closed-loop system, the air is first cooled and dehumidified by condensation on the condenser side of the dehumidification module to remove moisture, and then heated to 35-45°C by the heating circulation fan before being sent back into the cabin. The heated air increases the temperature of the cabin walls, seats, and seals, promoting the evaporation and desorption of adhering moisture. The water-containing air is then dehumidified by condensation on the condenser side, forming a synergistic cycle of heating, desorption, and condensation removal. This can reduce the relative humidity in the cabin to 40%-50% in a short time and effectively remove surface moisture, solving the problem that existing closed-loop dehumidification systems only reduce the humidity of the air but cannot remove surface moisture.

[0019] 2. Effectively prevent backflow of unfiltered air: During the replacement phase, the opening of the exhaust valve and / or the speed of the fresh air fan are controlled in a closed loop by a pressure sensor to maintain a slight positive pressure of 1.02 to 1.08 atm throughout the process; when switching from replacement to drying, a pressurized gradual switching method is adopted, which first gradually reduces the speed and closes the valve, and then stops the machine, avoiding the instantaneous negative pressure and pressure shock caused by directly stopping the valve, and preventing unfiltered air from flowing back into the cabin from the gaps in the door.

[0020] 3. Rapid oxygen replacement: The system employs a bottom-supply, top-exhaust airflow organization. Fresh air is introduced at low speed from the bottom of the cabin, forming a piston-like airflow that pushes the high-oxygen gas in the cabin upward and exhausts it from the top exhaust vent. This avoids large-scale mixing of fresh air with the cabin gas and short-circuiting of the fresh air. With an air supply volume of 8 to 18 times the cabin volume per hour, the oxygen concentration in the cabin can be reduced to 21% to 23% within 4 to 12 minutes.

[0021] 4. High degree of automation: Oxygen concentration, humidity and pressure sensors monitor in real time. The controller automatically completes depressurization, replacement, pressurized switching, closed dehumidification and delayed shutdown according to the set thresholds without manual intervention. It can also record and upload maintenance data, which is convenient for equipment operation and maintenance management. Attached Figure Description

[0022] In the attached diagram: Figure 1 This is a schematic flowchart illustrating the residual oxygen replacement and drying maintenance method for a micro-pressure oxygen chamber after use, as provided in an embodiment of the present invention. Figure 2 This is a system block diagram of the residual oxygen replacement and drying maintenance system for a micro-pressure oxygen chamber after use, provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the airflow organization during the residual oxygen replacement stage in a micro-pressure oxygen chamber provided in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures 1. Cabin; 2. Oxygen supply valve; 3. Fresh air intake valve; 4. Exhaust valve; 5. Fresh air fan; 6. HEPA filter; 7. Activated carbon filter; 8. Condenser dryer; 9. Air outlet; 10. Air outlet; 11. Heating and circulating fan; 12. Dehumidification module; 121. Condenser side; 122. Water collection tray; 123. Water seal pipe; 13. Oxygen concentration sensor; 14. Humidity sensor; 15. Pressure sensor; 16. Controller; 17. Communication module; 18. Ultraviolet germicidal lamp; 19. Remote server; 20. Photocatalytic module. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0025] like Figure 2 As shown, this embodiment provides a residual oxygen replacement and drying maintenance system for a micro-pressure oxygen chamber after use, applicable to micro-pressure oxygen chambers with an internal volume of 0.5–5 m³. The system includes a chamber body 1, an oxygen supply valve 2, a fresh air inlet valve 3, an exhaust valve 4, a fresh air fan 5, a HEPA filter 6, an activated carbon filter 7, a condenser dryer 8, a photocatalytic module 20, a heating and circulating fan 11, a dehumidification module 12, an oxygen concentration sensor 13, a humidity sensor 14, a pressure sensor 15, a controller 16, a communication module 17, an ozone-free ultraviolet germicidal lamp 18, and a remote server 19.

[0026] In the fresh air circulation path, the inlet of the fresh air fan 5 is sequentially connected to a HEPA filter 6 and an activated carbon filter 7. The outlet of the fresh air fan 5 is connected to the air supply vent 9 at the bottom of the cabin 1 via a condenser dryer 8, a photocatalytic module 20, and a fresh air intake valve 3. The exhaust valve 4 is connected to the exhaust vent 10 at the top of the cabin 1. The HEPA filter 6 is used to remove particulate matter from the fresh air, the activated carbon filter 7 is used to remove odors and organic gases, and the condenser dryer 8 is used to reduce the moisture content of the fresh air. The photocatalytic module 20 has a built-in UV-A ultraviolet light source and a TiO2 photocatalytic filter, which is used to catalytically oxidize and disinfect the dried fresh air, decompose organic pollutants, and kill microorganisms. The air supply vent 9 is located at the bottom of the cabin 1, and the exhaust vent 10 is located at the top of the cabin 1. The two are staggered in the height direction so that the fresh air forms an upward displacement airflow.

[0027] In the closed-loop airflow system, the dehumidification module 12 and the heating circulating fan 11 are connected in series between the return air inlet and the supply air outlet 9 of the cabin 1. Along the airflow direction, the condenser side 121 of the dehumidification module 12 is located upstream of the heating side of the heating circulating fan 11, meaning that the air inside the cabin first flows through the condenser side 121 to cool, condense, and dehumidify, and then is heated by the heating circulating fan 11 before being returned to the cabin. A water collection tray 122 is provided below the condenser side 121, and the water collection tray 122 is connected to the outside of the cabin via a water seal pipe 123, allowing condensate to be discharged without disrupting the cabin pressure. In this embodiment, the dehumidification module 12 is a semiconductor dehumidification module, the condenser side 121 is the cold end heat dissipation fin of the semiconductor cooling chip, and the heating side of the heating circulating fan 11 is the hot end heat dissipation fin of the semiconductor cooling chip.

[0028] Oxygen concentration sensor 13, humidity sensor 14, and pressure sensor 15 are installed inside the chamber and electrically connected to controller 16. In this embodiment, oxygen concentration sensor 13 is an electrochemical oxygen sensor, humidity sensor 14 is a capacitive humidity sensor, and pressure sensor 15 is a piezoresistive pressure sensor. Fresh air fan 5, heating circulation fan 11, dehumidification module 12, fresh air intake valve 3, exhaust valve 4, oxygen supply valve 2, and ultraviolet germicidal lamp 18 are all controlled by controller 16. The ultraviolet germicidal lamp 18 is ozone-free, with a radiation wavelength of 253.7nm, and does not produce ozone during operation. Controller 16 communicates with remote server 19 via communication module 17.

[0029] like Figure 1 As shown, the method for residual oxygen replacement and drying maintenance of a micro-pressure oxygen chamber after use using the above system includes the following steps.

[0030] Step S1: Depressurization. After the micro-pressure oxygen chamber is used, the operator leaves chamber 1 and closes the door. Controller 16 controls the oxygen supply valve 2 to close and confirms that the door is in a sealed closed state. Subsequently, controller 16 controls the exhaust valve 4 to open, slowly releasing the pressure inside the chamber from the working pressure to 1.02-1.08 atm. In this embodiment, the pressure is released to 1.05 atm. During the depressurization process, the door remains closed to prevent unfiltered external air from directly entering.

[0031] Step S2: Residual Oxygen Replacement. Controller 16 opens the fresh air intake valve 3 and exhaust valve 4, and starts the fresh air fan 5. The air supply volume of the fresh air fan 5 is set to 8 to 18 times the internal volume of the cabin per hour. In this embodiment, the internal volume of the cabin is 1m³, and the air supply volume is 12m³ / h, i.e., 12 times / hour. The fresh air sequentially passes through the HEPA filter 6 to remove particulate matter, the activated carbon filter 7 to remove odors and organic gases, and the condenser dryer 8 to dry to a relative humidity below 40%. Then, it is catalytically disinfected by the photocatalytic module 20 and delivered into the cabin at a low speed of 0.3 to 1.0m / s through the air outlet 9 at the bottom of the cabin 1. In this embodiment, the air supply speed is 0.5m / s. Figure 3As shown, the low-speed fresh air forms a piston-like displacement airflow that pushes upwards in the cabin, pushing the residual high-oxygen gas after use upwards as a whole. The high-oxygen gas is discharged from the exhaust port 10 at the top of the cabin 1 through the exhaust valve 4.

[0032] During the replacement process, pressure sensor 15 collects the cabin pressure in real time and feeds it back to controller 16. Controller 16 uses a PID algorithm to adjust the opening of exhaust valve 4 (when fresh air fan 5 is running at a constant speed), or adjusts the speed of fresh air fan 5 (when the opening of exhaust valve 4 is fixed), or uses a split-range control method to adjust both simultaneously, so that the cabin pressure is maintained at 1.02-1.08 atm. In this embodiment, it is maintained at 1.05 atm, with a control accuracy of 0.005 atm. By maintaining a slight positive pressure, the gas in the cabin can only be discharged from exhaust valve 4, and unfiltered external air will not flow back in through gaps such as cabin doors. Oxygen concentration sensor 13 detects the oxygen concentration in the cabin in real time and sends the signal to controller 16.

[0033] Step S3: Pressurized switching and heating circulation dehumidification. When the oxygen concentration sensor 13 detects that the oxygen concentration in the chamber has dropped to 21%–23% (in this embodiment, the threshold is set to 21.5%), the controller 16 determines that the residual oxygen replacement is complete. At this time, the controller 16 does not directly stop the fresh air fan 5 and close the valve, but first gradually reduces the speed of the fresh air fan 5 and simultaneously closes the exhaust valve 4 within 30–120 seconds. In this embodiment, this gradual change process lasts for 60 seconds, and during the gradual change process, the pressure in the chamber is kept at 1.02–1.08 atm through pressure closed-loop control. After the gradual change is completed, the controller 16 closes the fresh air intake valve 3 and the exhaust valve 4, stops the fresh air fan 5, and then starts the heating circulation fan 11 and the dehumidification module 12. In some embodiments, the controller 16 can gradually reduce the speed of the fresh air fan 5 and simultaneously close the exhaust valve 4 according to a linear decreasing curve or a step decreasing curve, as long as the gradual switching can be completed within 30–120 seconds and a slight positive pressure is maintained in the chamber.

[0034] During the closed-loop circulation phase, the cabin air, driven by the heating and circulating fan 11, first flows through the condenser side 121 of the dehumidification module 12. The surface temperature of the condenser side 121 is controlled at 5-15°C, and in this embodiment, it is 8°C. The water vapor in the air condenses on the surface of the cold-end heat dissipation fins and is removed. The condensate is collected in the water collection tray 122 and discharged to the outside of the cabin through the water seal pipe 123. The dehumidified air then flows through the heating side of the heating and circulating fan 11 and is heated to 35-45°C, and in this embodiment, to 40°C, before being sent back into the cabin. The heated air increases the temperature of the cabin walls, seats, and seals, causing the moisture adhering to their surfaces to evaporate and desorb into the air. The water-containing air is then removed by condensation on the condenser side 121 in the next cycle, forming a synergistic cycle of heating, desorption, condensation, and removal. The humidity sensor 14 detects the relative humidity inside the cabin in real time and sends a signal to the controller 16.

[0035] During the closed-loop cycle, the controller 16 can also activate the ozone-free ultraviolet germicidal lamp 18 to irradiate the chamber for 10-20 minutes, or 15 minutes in this embodiment. Since the oxygen concentration in the chamber has dropped to 21%-23% at this time, and the ultraviolet germicidal lamp 18 is a 253.7nm ozone-free type, it does not produce ozone during operation, thus combining safety and sterilization effect.

[0036] Step S4: Complete maintenance. When the humidity sensor 14 detects that the relative humidity inside the chamber has dropped to 40%–50% (in this embodiment, the threshold is set to 45%), the controller 16 controls the heating circulating fan 11 and the dehumidification module 12 to continue running for 1–5 minutes. In this embodiment, there is a 2-minute delay to allow residual moisture on the chamber walls and sealing surfaces to be fully desorbed and removed. Subsequently, the heating circulating fan 11 and the dehumidification module 12 are stopped, and the fresh air intake valve 3, exhaust valve 4, and oxygen supply valve 2 are closed to complete residual oxygen replacement and drying maintenance. Afterward, the controller 16 records the start and end times of this maintenance, the final oxygen concentration, and the final humidity data, and uploads them to the remote server 19 via the communication module 17, so that users or maintenance personnel can view the equipment maintenance status.

[0037] Under the experimental conditions of this embodiment, the chamber volume was 1m³. After use, the initial oxygen concentration inside the chamber was 28%, the initial temperature was 26°C, and the initial relative humidity was 75%. Condensation was visible on the chamber walls and seat surfaces. Using the method of this embodiment, the fresh air supply volume was 12m³ / h. During the replacement phase, the oxygen concentration inside the chamber decreased to 21.5% in about 6 minutes; the pressurized switching gradual process lasted 60 seconds; and the closed-loop heating and dehumidification phase lasted about 10 minutes, reducing the relative humidity inside the chamber to 45%. After a 2-minute delay, the machine was shut down, and the chamber walls and seals were dry with no visible water marks.

[0038] To compare the technical effects of the present invention, four schemes were tested under the same experimental conditions, and the results are shown in Table 1. Scheme A is to open the cabin door for natural ventilation and air drying; Scheme B is to turn on the fresh air fan 5 and exhaust valve 4 for direct exhaust of fresh air, but without bottom-to-top exhaust flow organization and pressure closed-loop control; Scheme C is to directly stop the valve after fresh air replacement and then switch to closed-loop heating and dehumidification, that is, without using pressurized gradual switching; Scheme D is the method of this embodiment.

[0039] Table 1 Comparison of maintenance effects of different schemes plan Time required for oxygen concentration to drop to 22.5% Time required for relative humidity to drop to 45% Pressure fluctuations inside the cabin during switching 0.5m particulate matter concentration inside the chamber Option A: Open the hatch for natural ventilation and air drying. 28min >60min (still 58% at 60min) Approximately 120,000 grains / ft Option B: Direct exhaust of fresh air, without bottom supply and top exhaust or pressure closed loop. 15min 22min Approximately -150 Pa (backflow occurs) Approximately 85,000 grains / ft Option C: Fresh air replacement + closed-loop dehumidification, without pressurized switching 9min 14min Approximately -80Pa Approximately 52,000 grains / ft Option D: The method in this embodiment 6min 10min 20Pa Approximately 8000 grains / ft As shown in Table 1, compared with natural ventilation, the residual oxygen replacement time of this invention is shortened from 28 min to 6 min, and the drying time is shortened from over 60 min to 10 min. Compared with schemes B and C, which do not perform pressure closed-loop control and pressurized switching, this invention controls the pressure fluctuation inside the chamber to within 20 Pa during switching, without negative pressure backflow, and the concentration of particulate matter inside the chamber is significantly reduced, indicating that the micro-positive pressure closed-loop control and pressurized gradual switching effectively prevent backflow of unfiltered external air. In addition, in the closed-loop circulation stage, the air path configuration of first condensing dehumidification and then heating, combined with 40°C heating, allows the moisture adhering to the surface of the chamber wall to be desorbed and removed within about 10 min; while using the same dehumidification module 12 but without heating (only condensing dehumidification), it takes about 20 min to remove the surface moisture, indicating that heating desorption and condensation removal have a synergistic effect.

[0040] In this invention, the chamber volume of 0.5–5 m³ can accommodate single-person and double-person soft-sided micro-pressure oxygen chambers, as well as small hard-sided micro-pressure oxygen chambers. With a fresh air supply volume of 8–18 times the chamber volume per hour, combined with a bottom-supply, top-exhaust replacement airflow, the residual oxygen replacement time is 4–12 minutes. After use, the initial oxygen concentration inside the micro-pressure oxygen chamber is typically 25%–32%. Under the aforementioned airflow volume and organization conditions, the piston-type replacement airflow only requires approximately 1–1.5 times the chamber volume of fresh air to expel the high-oxygen gas outside, thus reducing the oxygen concentration to 21%–23% within 4–12 minutes. The heating temperature is set at 35–45°C, which promotes surface moisture evaporation without causing excessive internal temperature and accelerating the aging of seals. The target relative humidity is set at 40%–50%, which inhibits metal corrosion and mold growth while avoiding excessive dehumidification that could cause seals to crack. The gradual switching time is set to 30–120 seconds: if it is shorter than 30 seconds, the fan speed and valve opening change too quickly, which may still cause pressure fluctuations or even instantaneous negative pressure in the chamber; if it is longer than 120 seconds, the residence time of high-oxygen gas after residual oxygen replacement is unnecessarily extended, increasing the risk of oxidation. The surface temperature of the condenser side 121 is set to 5–15°C: if it is higher than 15°C, the condensation driving force is insufficient under low humidity conditions; if it is lower than 5°C, the fin surface is prone to frost formation, which reduces dehumidification efficiency and increases energy consumption.

[0041] In other embodiments, the heating side of the heating circulating fan 11 may also be an independent electric heater; the air outlet 9 may be a slotted or perforated plate type, as long as it can form a low-speed upward displacement airflow inside the chamber; the controller 16 may be a PLC, microcontroller, or other programmable controller; the communication module 17 may use Wi-Fi, Bluetooth, 4G, or Ethernet communication. The ultraviolet germicidal lamp 18 may be turned on synchronously during the closed-loop process or after drying is completed. All the above variations should be included within the protection scope of this invention.

[0042] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber, characterized in that, Includes the following steps: Step S1: After the use of the micro-pressure oxygen chamber is completed, close the oxygen supply valve (2), confirm that the chamber door is sealed and closed, and release the pressure inside the chamber to 1.02 to 1.08 atm through the exhaust valve (4); Step S2: Open the fresh air intake valve (3) and the exhaust valve (4), start the fresh air fan (5), and send the filtered and dried fresh air into the cabin through the air outlet (9) at the bottom of the cabin (1). The gas in the cabin is discharged through the exhaust outlet (10) at the top of the cabin (1) through the exhaust valve (4), forming a displacement airflow from bottom to top. The controller (16) adjusts the opening of the exhaust valve (4) and / or the speed of the fresh air fan (5) according to the pressure signal collected by the cabin pressure sensor (15) to maintain the cabin pressure at 1.02 to 1.08 atm, and uses the fresh air to replace the residual oxygen in the cabin. The oxygen concentration in the cabin is monitored in real time by the oxygen concentration sensor (13). Step S3: When the oxygen concentration sensor (13) detects that the oxygen concentration in the cabin has dropped to 21% to 23%, the controller (16) first gradually reduces the speed of the fresh air fan (5) and simultaneously closes the exhaust valve (4) within 30 to 120 seconds. While maintaining the cabin pressure at 1.02 to 1.08 atm, the controller closes the fresh air intake valve (3) and the exhaust valve (4) and stops the fresh air fan (5). Then, the heating circulation fan (11) and the dehumidification module (12) are started, so that the air in the cabin first flows through the condenser side (121) of the dehumidification module (12) to cool down, condense, and dehumidify. Then, the air is heated to 35 to 45°C by the heating circulation fan (11) and sent back into the cabin to form a closed loop. The relative humidity in the cabin is monitored in real time by the humidity sensor (14). Step S4: When the humidity sensor (14) detects that the relative humidity in the cabin has dropped to 40% to 50%, the heating circulation fan (11) and the dehumidification module (12) are stopped, and the fresh air intake valve (3), the exhaust valve (4) and the oxygen supply valve (2) are closed to complete the residual oxygen replacement and drying maintenance.

2. The method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber according to claim 1, characterized in that, The air supply volume of the fresh air fan (5) in step S2 is 8 to 18 times the internal volume of the micro-pressure oxygen chamber (1) per hour. The internal volume of the micro-pressure oxygen chamber is 0.5 to 5 m. The duration of residual oxygen replacement in step S2 is 4 to 12 min.

3. The method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber according to claim 1, characterized in that, The air supply velocity of the air outlet (9) in step S2 is 0.3 to 1.0 m / s, so that the fresh air forms a piston-like displacement airflow that pushes upward in the cabin.

4. The method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber according to claim 1, characterized in that, In step S2, the controller (16) uses a PID algorithm or split-range control method to adjust the opening of the exhaust valve (4) and / or the speed of the fresh air fan (5), and the control accuracy of the cabin pressure is 0.005 atm.

5. The method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber according to claim 1, characterized in that, In step S3, the controller (16) gradually reduces the speed of the fresh air fan (5) according to a linear decreasing curve or a step decreasing curve and simultaneously closes the exhaust valve (4).

6. The method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber according to claim 1, characterized in that, In step S3, the heating circulating fan (11) heats the air after it has been dehumidified by the dehumidification module (12) to 40°C. The dehumidification module (12) is a semiconductor dehumidification module. The surface temperature of the condenser side (121) of the dehumidification module (12) is 5-15°C. The condensate generated by condensation is discharged to the outside of the cabin through the water collection tray (122) and the water seal pipe (123).

7. The method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber according to claim 1, characterized in that, In step S2, the fresh air introduced passes through a HEPA filter (6), an activated carbon filter (7), a condenser dryer (8), and a photocatalytic module (20) in sequence. After being dried by the condenser dryer (8) to a relative humidity of less than 40%, it enters the cabin after being catalytically disinfected by the photocatalytic module (20).

8. The method for residual oxygen replacement and drying maintenance after use of a micro-pressure oxygen chamber according to claim 1, characterized in that, In step S4, when the relative humidity inside the chamber drops to 40% to 50%, the heating circulating fan (11) and the dehumidification module (12) continue to run for 1 to 5 minutes and then stop. During the closed-loop process in step S3 or after step S4 is completed, the ozone-free ultraviolet germicidal lamp (18) is started to irradiate the chamber for 10 to 20 minutes. The radiation wavelength of the ultraviolet germicidal lamp (18) is 253.7 nm. After step S4, the controller (16) records the start and end time of this maintenance, the final oxygen concentration and the final humidity data, and uploads them to the remote server (19) through the communication module (17).

9. A residual oxygen replacement and drying maintenance system for a micro-pressure oxygen chamber after use, comprising a chamber body (1), an oxygen supply valve (2), a fresh air inlet valve (3), an exhaust valve (4), a fresh air fan (5), a HEPA filter (6), an activated carbon filter (7), a condenser dryer (8), a photocatalytic module (20), an air outlet (9), an air outlet (10), a heating circulating fan (11), a dehumidification module (12), an oxygen concentration sensor (13), a humidity sensor (14), a pressure sensor (15), a controller (16), a communication module (17), an ozone-free ultraviolet germicidal lamp (18), and a remote server (19), characterized in that, The oxygen concentration sensor (13) is an electrochemical oxygen sensor, the humidity sensor (14) is a capacitive humidity sensor, and the pressure sensor (15) is a piezoresistive pressure sensor; the inlet of the fresh air fan (5) is connected in sequence to the HEPA filter (6) and the activated carbon filter (7), and the outlet of the fresh air fan (5) is connected to the air outlet (9) at the bottom of the cabin (1) via the condenser dryer (8), the photocatalytic module (20), and the fresh air intake valve (3); the exhaust valve (4) is connected to the exhaust port (10) at the top of the cabin (1); the dehumidification module (12) and the heating circulating fan (11) are connected in series in the closed-loop air path between the circulating return air port and the air outlet (9) of the cabin (1), and the condenser side (121) of the dehumidification module (12) is located in the heating circulating fan. A water collection tray (122) is provided upstream of the air inlet on the heating side of the hot circulating fan (11) and below the condenser side (121). The water collection tray (122) is connected to the outside of the cabin via a water seal pipe (123). The oxygen concentration sensor (13), the humidity sensor (14), the pressure sensor (15), and the ultraviolet germicidal lamp (18) are all electrically connected to the controller (16). The fresh air fan (5), the heating circulating fan (11), the dehumidification module (12), the fresh air inlet valve (3), the exhaust valve (4), and the oxygen supply valve (2) are all controlled by the controller (16). The controller (16) is configured to perform the method described in claim 1 and is configured to record the start and end time of maintenance, the final oxygen concentration, and the final humidity data and upload them to the remote server (19) via the communication module (17).

10. The residual oxygen replacement and drying maintenance system for a micro-pressure oxygen chamber after use, as described in claim 9, is characterized in that... The dehumidification module (12) is a semiconductor dehumidification module, the condenser side (121) is the cold end heat dissipation fin of the semiconductor cooling chip, and the heating side of the heating circulating fan (11) is the hot end heat dissipation fin of the semiconductor cooling chip or an independent electric heater.

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