Flow detection device with environment temperature and humidity and gas concentration identification function

Abstract

The invention discloses a flow detection device with environment temperature and humidity and gas concentration recognition, and relates to the pneumatic field, the flow detection device comprises a gas pipe partial pressure part and a gas flow monitoring part, the gas pipe partial pressure part comprises a gas flow pipeline and a partial pressure hole, the partial pressure hole is embedded in the center of the inner wall of the gas flow pipeline, the diameter range of the partial pressure hole is 2-6 mm, and the gas flow monitoring part is connected with the gas flow pipeline. The partial pressure hole is used for dissipating air flow in the air flow pipeline to the outside, the partial pressure hole is connected with the air flow monitoring part through a soft air pipe, and the soft air pipe is used for stably guiding dissipated air into the air flow monitoring part; through the design of the partial pressure hole of the partial pressure part of the gas pipe, the stable transmission of the soft gas pipe, the friction electric signal collection of the contact layer and the copper film, and the Bernoulli equation, the gas flow is calculated, the problem that the sensitivity of a traditional sensor is insufficient in the 10Pa extreme vacuum environment is solved, and the high-precision detection of trace gas flow in the vacuum environment is realized.

Description

Technical Field

[0001] This invention relates to pneumatic technology, specifically to a flow detection device that identifies ambient temperature and humidity as well as gas concentration. Background Technology

[0002] In the aerospace field, accurate monitoring of gas flow in vacuum or near-vacuum environments is a key technology for ensuring the safe operation of spacecraft. Flow sensors are devices capable of real-time detection, measurement, and monitoring of the instantaneous or cumulative flow of fluids such as gases and liquids. They are widely used in industrial production, energy supply, aerospace, and other fields. Their core function is to convert fluid flow signals into measurable and transmissible electrical signals or other identifiable signals, providing data support for system operation control and status assessment. In the aerospace field, critical aspects such as fuel supply for spacecraft propulsion systems, gas circulation in life support systems, and cabin environment control all rely on accurate gas flow monitoring data in vacuum or near-vacuum environments. The monitoring results directly affect the spacecraft's dynamic stability, equipment operational safety, and astronaut safety, making it one of the core technologies for ensuring reliable on-orbit operation of spacecraft.

[0003] Traditional gas flow detection typically employs differential pressure, thermal, or ultrasonic flow sensors. These sensors generally rely on the physical or chemical interaction between the fluid and sensor components. For example, differential pressure sensors calculate flow rate by detecting the pressure difference as the fluid passes through a throttling device, while thermal sensors sense flow rate through the heat carried away by the fluid from a heating element. However, under the extreme vacuum conditions of spacecraft, when the ambient pressure drops to 10⁻⁻⁶, 5 At a certain temperature (Pa), the density of gas molecules decreases significantly, and the interaction strength between the fluid and sensor components weakens considerably. This leads to a sharp drop in the detection sensitivity of conventional sensors, and in some cases, they may even fail to capture effective flow signals. Furthermore, spacecraft must withstand drastic temperature changes from -180°C to 150°C, strong space radiation, and long-term microgravity environments during launch, on-orbit operation, and reentry. Traditional flow sensors often employ rigid structural designs, whose materials are prone to embrittlement and cracking under extreme temperature changes. The structure is also susceptible to deformation due to stress concentration. Simultaneously, the internal electronic components of the sensor are easily affected by radiation interference, resulting in signal drift. This further reduces sensor detection accuracy and shortens lifespan, making it difficult to meet the spacecraft's requirements for long-term stable monitoring of gas flow. Summary of the Invention

[0004] The purpose of this invention is to provide a flow detection device with the ability to identify ambient temperature and humidity and gas concentration, so as to solve the problems of insufficient sensitivity of flow sensors in vacuum environment, reliability risks caused by structural rigidity and poor spatial adaptability in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a flow detection device with ambient temperature and humidity and gas concentration recognition, comprising a gas tube pressure distribution part and a gas flow monitoring part;

[0006] The pressure-splitting section of the air duct includes an airflow duct and a pressure-splitting hole. The pressure-splitting hole is embedded in the center of the inner wall of the airflow duct. The diameter of the pressure-splitting hole ranges from 2 to 6 mm. The pressure-splitting hole is used to disperse the airflow in the airflow duct to the outside. The pressure-splitting hole is connected to the gas flow monitoring section through a flexible air tube. The flexible air tube is used to stably introduce the dispersed gas into the gas flow monitoring section.

[0007] The gas flow monitoring section includes symmetrically arranged cavities on both sides, a contact layer, a multimodal sensor group, and a four-level sealing system. The symmetrically arranged cavities on both sides are fastened together by long screws. The four-level sealing system includes a hard sealing ring, a rubber ring, a sponge pad, and an adhesive filling layer. The hard sealing ring, rubber ring, and sponge pad are sequentially arranged at the connection parts of the cavities and are filled with adhesive to form a seal to prevent gas leakage from the cavities.

[0008] The inner wall of the cavity has a groove with a depth of 0.1 to 0.5 mm. A copper film is attached to the groove. The contact layer is composed of a multi-layer structure. The first layer is a triboelectric layer, which is made of polytetrafluoroethylene (PTFE) polymer. The second layer is a piezoelectric layer, which is made of polyvinylidene fluoride (PVDF) material.

[0009] The multimodal sensor group is disposed on the cavity groove wall of the high-voltage side of the contact layer or the high-voltage side. The multimodal sensor group includes a temperature sensor, a humidity sensor and an electrochemical sensor. The electrochemical sensor is a heterogeneous biofilm sensor and can be self-powered by the voltage generated by the piezoelectric layer.

[0010] Furthermore, the flexible air tube is made of silicone rubber or polyurethane elastomer, and the inner diameter of the flexible air tube matches the diameter of the pressure dividing hole.

[0011] Furthermore, the thickness of the copper film is 10-50 μm, and the surface roughness Ra of the copper film is ≤0.5 μm.

[0012] Furthermore, the triboelectric layer and the piezoelectric layer are compositely formed by electrospinning, and the thickness ratio of the triboelectric layer to the piezoelectric layer is 1:0.5-1.5.

[0013] Furthermore, the electrochemical sensor includes a substrate, an electrode, and a modification layer; the substrate is made of polyimide (PI) or polydimethylsiloxane (PDMS), the electrode is made of a metal conductive material or a carbon-based material, and the modification layer is made of ZnO or ZnS inorganic semiconductor gas-sensitive material.

[0014] Furthermore, the pressure dividing holes are evenly distributed along the axial direction of the airflow pipe, and the spacing between the pressure dividing holes is 5 to 15 mm.

[0015] Furthermore, the bottom of the groove of the cavity 4 is provided with an air guiding microstructure, which is a strip-shaped protrusion with a width of 0.05 to 0.2 mm.

[0016] Furthermore, the polarization direction of the piezoelectric layer is perpendicular to the airflow direction, and the polarization intensity of the piezoelectric layer is 30-70mV / N.

[0017] Furthermore, the signal output terminals of both the temperature sensor and the humidity sensor are connected to the data processing unit, which is used to compensate for the interference of environmental parameters on the gas monitoring results.

[0018] Furthermore, the sensitive membrane material of the biomembrane sensor is functionalized nanofiber, and the surface of the sensitive membrane is loaded with gas-specific recognition sites. The detection limit of the biomembrane sensor is as low as 10 ppm.

[0019] Compared with the prior art, the flow detection device provided by the present invention, which identifies ambient temperature and humidity and gas concentration, has the following advantages:

[0020] 1. This invention solves the problem of traditional sensors operating at 10⁻⁻⁶ by using a pressure-splitting orifice design in the tracheal pressure-splitting section and stable transmission through a flexible tracheal tube, combined with the triboelectric signal acquisition between the contact layer and the copper film, and calculating the gas flow rate using Bernoulli's equation. 5 This addresses the issue of insufficient sensitivity under extreme vacuum conditions, enabling high-precision detection of trace gas flow in vacuum environments.

[0021] 2. This invention converts mechanical displacement into electrical energy through the PVDF piezoelectric layer in the contact layer to power the electrochemical sensor, eliminating the need for an external power source and improving the device's adaptability in spacecraft scenarios where there is no external power supply.

[0022] 3. This invention integrates temperature, humidity and gas concentration detection functions through a multi-modal sensor group, and the temperature and humidity sensor signals can compensate for environmental interference, improving the accuracy of gas flow and concentration monitoring results and realizing multi-parameter synchronous monitoring.

[0023] 4. This invention uses flexible materials for the soft air tube and the composite molded contact layer, which avoids the problem of embrittlement and cracking of traditional rigid sensors under drastic temperature changes. At the same time, the four-level sealing system of the cavity prevents gas leakage, ensuring the long-term stable operation of the device in the complex environment of spacecraft and improving its adaptability to extreme environments.

[0024] 5. This invention improves the conversion efficiency of mechanical signals to electrical signals by designing the polarization direction of the piezoelectric layer to be perpendicular to the airflow direction and the polarization intensity to be adapted. The low surface roughness of the copper film enhances the charge transfer efficiency, further improving the detection response speed and data reliability. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0026] Figure 1 This is a schematic diagram of the main view structure provided in an embodiment of the present invention;

[0027] Figure 2 Provided for embodiments of the present invention Figure 1 A schematic diagram of the side view structure;

[0028] Figure 3 This is a schematic diagram of the tracheal pressure-reducing section provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the pressure dividing hole provided in an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the gas flow detection section provided in an embodiment of the present invention;

[0031] Figure 6 A schematic diagram illustrating the working principle of an embodiment of the present invention;

[0032] Figure 7 This is a layout diagram of the multimodal sensor group provided in an embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of the multimodal sensor group structure provided in an embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram of the four-level sealing system provided in an embodiment of the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Airflow duct; 2. Pressure dividing hole; 3. Flexible air tube; 4. Cavity; 5. Copper film; 6. Contact layer; 7. Triboelectric layer; 8. Piezoelectric layer; 9. Multimodal sensor group; 10. Temperature sensor; 11. Humidity sensor; 12. Electrochemical sensor; 13. Substrate; 14. Electrode; 15. Modification layer; 16. Long screw; 17. Hard sealing ring; 18. Rubber ring; 19. Sponge pad. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] As attached Figure 1 To be continued Figure 9 As shown:

[0039] Example 1:

[0040] This invention provides a flow detection device with ambient temperature and humidity and gas concentration recognition, including a gas tube pressure distribution part and a gas flow monitoring part;

[0041] The tracheal pressure-splitting part includes an airflow pipe 1 and a pressure-splitting hole 2. The pressure-splitting hole 2 is embedded in the center of the inner wall of the airflow pipe 1. The diameter of the pressure-splitting hole 2 ranges from 2 to 6 mm. The pressure-splitting hole 2 is used to dissipate the airflow in the airflow pipe 1 to the outside. The pressure-splitting hole 2 is connected to the gas flow monitoring part through a flexible air tube 3. The flexible air tube 3 is used to stably introduce the dissipated gas into the gas flow monitoring part.

[0042] Pressure dividing holes 2 are evenly distributed along the axial direction of airflow pipe 1, and the hole spacing of pressure dividing holes 2 is 5-15mm;

[0043] The flexible air tube 3 is made of silicone rubber or polyurethane elastomer, and the inner diameter of the flexible air tube 3 matches the diameter of the pressure dividing hole 2.

[0044] The gas flow monitoring section includes two symmetrically arranged cavities 4, a contact layer 6, a multimodal sensor group 9, and a four-level sealing system. The two symmetrically arranged cavities 4 are fastened together by long screws 16. The four-level sealing system includes a hard sealing ring 17, a rubber ring 18, a sponge pad 19, and an adhesive filling layer. The hard sealing ring 17, the rubber ring 18, and the sponge pad 19 are sequentially arranged at the connection parts of the cavities 4 and form a seal with the adhesive filling to prevent gas leakage in the cavities 4.

[0045] The bottom of the groove of the cavity 4 is provided with a gas guiding microstructure, which is a strip-shaped protrusion with a width of 0.05 to 0.2 mm. The inner wall of the cavity 4 is provided with a groove with a depth of 0.1 to 0.5 mm. A copper film 5 is attached in the groove. The thickness of the copper film 5 is 10-50 μm, and the surface roughness Ra of the copper film 5 is ≤0.5 μm.

[0046] The contact layer 6 is composed of a multi-layer structure. The first layer is the triboelectric layer 7, which is made of polytetrafluoroethylene (PTFE) polymer. The second layer is the piezoelectric layer 8, which is made of polyvinylidene fluoride (PVDF) material.

[0047] The multimodal sensor group 9 is disposed on the high-voltage side of the contact layer 6 or on the groove wall of the cavity 4 on the high-voltage side. The multimodal sensor group 9 includes a temperature sensor 10, a humidity sensor 11 and an electrochemical sensor 12. The electrochemical sensor 12 is a heterogeneous biofilm sensor, and the electrochemical sensor 12 can be self-powered by the voltage generated by the piezoelectric layer 8.

[0048] The signal output terminals of temperature sensor 10 and humidity sensor 11 are both connected to the data processing unit, which is used to compensate for the interference of environmental parameters on the gas monitoring results.

[0049] The sensitive membrane material of the biomembrane sensor is functionalized nanofiber, and the surface of the sensitive membrane is loaded with gas-specific recognition sites. The detection limit of the biomembrane sensor is as low as 10 ppm.

[0050] Working principle: First, the airflow in the spacecraft's gas path enters the airflow duct 1. When the airflow flows stably in the duct, some gas will escape through the pressure-distributing holes 2 embedded in the center of the inner wall. The pressure-distributing holes 2 are evenly distributed along the axial direction of the airflow duct 1 with a spacing of 5-15 mm. This distribution method can balance the airflow pressure and avoid local pressure fluctuations affecting the subsequent monitoring accuracy. The escaped gas is introduced into the gas flow monitoring section through the flexible air tube 3. The flexible air tube 3 is made of silicone rubber or polyurethane elastomer, and its inner diameter matches the diameter of the pressure-distributing holes 2. This can buffer changes in airflow pressure to ensure stable gas transmission and also accommodate small displacements between the airflow duct 1 and the cavity 4 to prevent leakage during gas transmission.

[0051] Next, the gas entering the gas flow monitoring section is guided by a strip-shaped gas-guiding microstructure with a width of 0.05-0.2mm at the bottom of the groove in the cavity 4, and flows directionally to the contact layer 6. The gas-guiding microstructure can prevent the gas from spreading randomly in the cavity 4, ensuring that the gas acts on the contact layer 6 in a concentrated manner, thereby improving the monitoring response speed. At the same time, the two cavities 4 are fastened together by long screws 16, and a four-level sealing system (hard sealing ring 17, rubber ring 18, sponge pad 19 and glue filling layer) acts on the connection part of the cavity 4 in sequence: the hard sealing ring 17 prevents gas from leaking from the gaps on the end face of the cavity 4, the rubber ring 18 fills the tiny gaps, the sponge pad 19 buffers the fastening pressure of the long screws 16, and the glue achieves all-round sealing, effectively preventing gas leakage in the cavity 4 and ensuring the stability of the gas pressure difference generated by the gas.

[0052] Subsequently, a stable pressure difference drives the contact layer 6 to shift towards the copper film 5 within the groove of the cavity 4. The copper film 5, with a thickness of 10-50 μm and a surface roughness Ra≤0.5 μm, enhances the adsorption and charge transfer efficiency of gas molecules, providing a stable foundation for electrical signal acquisition. During the shift of the contact layer 6, the triboelectric layer 7 (polytetrafluoroethylene PTFE polymer) on its surface dynamically contacts and rubs against the copper film 5, generating a triboelectric voltage. This voltage corresponds to the transient flow rate of the detected gas. The data processing unit receives this triboelectric voltage signal and calculates the instantaneous gas flow rate value using Bernoulli's equation. The gas flow rate calculation follows the formula "Q=0.0325×2(V1 / V2) / ρ" (ρ is the gas density, and V1 and V2 are related parameters of the triboelectric voltage). By analyzing the variation law of the triboelectric voltage, the magnitude of the transient gas flow rate can be accurately deduced. Meanwhile, the piezoelectric layer 8 (polyvinylidene fluoride PVDF material) of the contact layer 6 will bend and deform as the contact layer shifts, thereby generating a piezoelectric voltage. This piezoelectric voltage can capture the dynamic changes in the flow velocity inside the pipe in real time, which is equivalent to monitoring the dynamic process of gas flow. It complements the transient flow detection of the triboelectric layer. This piezoelectric voltage can also detect the changes in the flow velocity inside the pipe at the same time, which is equivalent to the transient flow rate measured by triboelectric testing. Piezoelectric testing measures the dynamic changes in flow velocity.

[0053] Simultaneously, the piezoelectric voltage generated by the piezoelectric layer 8 converts the mechanical energy generated by the offset of the contact layer 6 into electrical energy, which directly powers the electrochemical sensor 12 in the multimodal sensor group 9. The electrochemical sensor 12 is a heterogeneous biofilm sensor that can operate without an external power source. Subsequently, the multimodal sensor group 9 is activated synchronously: the sensitive membrane material of the electrochemical sensor 12 is a functionalized nanofiber with gas-specific recognition sites loaded on its surface, and the detection limit is as low as 10 ppm. It can capture changes in gas component concentration in real time and output signals. The temperature sensor 10 and the humidity sensor 11 synchronously collect ambient temperature and humidity signals around the device, and the signal output terminals of both are connected to the data processing unit.

[0054] Finally, the data processing unit compensates and corrects the monitoring results of transient gas flow rate, dynamic flow rate and concentration based on the environmental parameters collected by the temperature sensor 10 and the humidity sensor 11; avoiding interference such as triboelectric signal drift, piezoelectric signal fluctuation and gas molecule activity change caused by changes in environmental temperature and humidity, and ultimately achieving accurate synchronous monitoring of transient gas flow rate, dynamic flow rate, environmental temperature and humidity and gas concentration in a vacuum environment.

[0055] Example 2:

[0056] This embodiment is basically the same as the previous embodiment, except that the triboelectric layer 7 and the piezoelectric layer 8 are compositely formed by electrospinning, and the thickness ratio of the triboelectric layer 7 to the piezoelectric layer 8 is 1:0.5-1.5.

[0057] The polarization direction of the piezoelectric layer 8 is perpendicular to the gas flow direction, and the polarization intensity of the piezoelectric layer 8 is 30-70mV / N.

[0058] Working principle: First, after the gas flow enters the gas flow duct 1, part of the gas escapes through the pressure dividing holes 2, which are evenly distributed along the axial direction (hole spacing 5-15mm). It is then stably transmitted to the gas flow monitoring section through the flexible gas tube 3 made of silicone rubber or polyurethane elastomer that matches the diameter of the pressure dividing holes 2. The elastic material of the flexible gas tube 3 can buffer the air flow impact and avoid pressure changes during gas transmission, ensuring the stability of the gas parameters entering the cavity 4.

[0059] Next, the gas entering the cavity 4 is guided by the strip-shaped gas-guiding microstructure (width 0.05-0.2mm) and acts directionally on the contact layer 6. The two cavities 4 are fastened by long screws 16. The four-level sealing system (hard sealing ring 17, rubber ring 18, sponge pad 19 and glue) effectively blocks external environmental interference, prevents gas leakage in the cavity 4, and ensures that the gas pressure difference generated by the gas can stably drive the contact layer 6 to shift towards the copper film 5 (thickness 10-50μm, Ra≤0.5μm). Since the triboelectric layer 7 (PTFE) and the piezoelectric layer 8 (PVDF) of the contact layer 6 are composite formed by electrospinning process, and the thickness ratio of the two is 1:0.5-1.5, this composite process can make the two materials tightly bonded. The thickness ratio design ensures that the triboelectric layer 7 can stably generate triboelectric signals. At the same time, the piezoelectric layer 8 can efficiently convert mechanical energy and sense the dynamic changes in flow velocity, realizing the synergistic effect of "triboelectric power generation to measure transient flow rate - piezoelectric deformation to measure dynamic flow velocity".

[0060] Then, when the contact layer 6 shifts, the triboelectric layer 7 contacts the copper film 5, generating a triboelectric voltage. This voltage corresponds to the transient gas flow rate. The data processing unit combines this voltage signal with Bernoulli's equation to calculate the instantaneous gas flow rate. Simultaneously, the piezoelectric layer 8, with its polarization direction perpendicular to the airflow direction and a polarization intensity of 30-70 mV / N, generates a piezoelectric voltage as the contact layer bends, which can accurately capture the dynamic changes in the flow velocity inside the tube and reflect the fluctuations in airflow velocity in real time. This complements the transient flow rate detection by triboelectricity, comprehensively covering both the static values ​​and dynamic processes of gas flow. This polarization design optimizes the mechanical-to-electrical signal conversion efficiency. When the airflow drives the contact layer 6 to shift, the polarization direction of the piezoelectric layer 8 is perpendicular to the force direction (airflow direction), maximizing the capture of mechanical deformation. The polarization intensity adaptation ensures that small mechanical energy can be converted into sufficient electrical energy, providing a more stable power supply for the electrochemical sensor 12 and ensuring the signal strength for dynamic flow rate monitoring.

[0061] Subsequently, the electrochemical sensor 12 (a biofilm sensor with a detection limit as low as 10 ppm) detects the gas concentration in real time and outputs a signal under the stable power supply of the piezoelectric layer 8; the temperature sensor 10 and the humidity sensor 11 synchronously collect the ambient temperature and humidity signals and transmit them to the data processing unit; finally, the data processing unit performs environmental interference compensation on the gas transient flow rate, dynamic flow rate and concentration monitoring results based on the temperature and humidity data; avoiding the influence of fluctuations in the conversion efficiency of the piezoelectric layer 8 caused by ambient temperature changes and changes in the adsorption characteristics of gas molecules caused by humidity, and ultimately achieving high-precision and stable monitoring of gas parameters in a vacuum environment.

[0062] Example 3:

[0063] This embodiment is basically the same as the previous embodiment, except that the electrochemical sensor 12 includes a substrate 13, an electrode 14 and a modification layer 15.

[0064] The substrate 13 is made of polyimide (PI) or polydimethylsiloxane (PDMS), the electrode 14 is made of a metal conductive material or a carbon-based material, and the modification layer 15 is made of ZnO or ZnS inorganic semiconductor gas-sensitive material.

[0065] Working principle: First, the airflow in the spacecraft's gas path enters the airflow pipe 1. Some of the gas escapes through the pressure dividing hole 2 (uniformly distributed along the axial direction, with a hole spacing of 5-15mm), and is stably introduced into the gas flow monitoring section through the silicone rubber or polyurethane elastomer soft gas tube 3 (with an inner diameter matching the pressure dividing hole 2). The soft gas tube 3 can effectively isolate the interference of external radiation and temperature changes on the transmitted gas, ensuring that the gas parameters do not change during the transmission process.

[0066] Next, the gas entering the cavity 4 is guided by the strip-shaped gas guiding microstructure (width 0.05-0.2mm) at the bottom of the groove, and the contact layer 6 is directionally driven to deflect towards the copper film 5 (thickness 10-50μm, Ra≤0.5μm). The two cavities 4 are fastened by long screws 16. The four-level sealing system can effectively prevent gas leakage in the cavity 4, avoid the weakening of the gas pressure difference due to leakage, and ensure the stability of the deflection of the contact layer 6. The triboelectric layer 7 (PTFE) and the piezoelectric layer 8 (PVDF) of the contact layer 6 are composited by electrospinning process (thickness ratio 1:0.5-1.5). During the deflection process, the triboelectric layer 7 contacts the copper film 5 to generate triboelectric voltage. The data processing unit combines this voltage signal with Bernoulli's equation to calculate the transient gas flow rate. At the same time, the piezoelectric voltage generated by the bending of the contact layer 8 can detect the dynamic changes of the flow velocity in the tube in real time, accurately capture the instantaneous fluctuations of the airflow velocity, and form a complementary function with the transient flow detection of the triboelectric layer to realize comprehensive monitoring of the gas flow state. Because the polarization direction of the piezoelectric layer 8 is perpendicular to the gas flow direction and the polarization intensity is 30-70mV / N, it can efficiently convert mechanical energy into electrical energy, providing continuous power supply for the electrochemical sensor 12.

[0067] Then, the electrochemical sensor 12 begins to operate: its substrate 13 is polyimide (PI) or polydimethylsiloxane (PDMS); PI material has a wide temperature range (-200℃ to 260℃) and PDMS has good flexibility, both of which can adapt to the severe temperature changes and microgravity environment of spacecraft, ensuring the stability of the sensor structure; the electrode 14 is made of a metal conductive material (such as copper or silver) or a carbon-based material (such as graphite or carbon nanotubes), which can ensure that the electrical energy output by the piezoelectric layer 8 is stably transmitted to the modification layer 15; the modification layer 15 is a ZnO or ZnS inorganic semiconductor gas-sensitive material; under the power supply of the piezoelectric layer 8, the semiconductor properties of ZnO / ZnS will change with the adsorption of gas molecules, and the electrode 14 converts this change into an electrical signal. Combined with the synergistic effect of the sensitive membrane (functionalized nanofibers, loaded with gas-specific recognition sites) of the electrochemical sensor 12, the gas components can be accurately identified and the concentration can be detected (detection limit as low as 10 ppm).

[0068] Subsequently, temperature sensor 10 and humidity sensor 11 collect ambient temperature and humidity signals and transmit them to the data processing unit. The temperature signal can correct the temperature-sensitive drift of ZnO / ZnS semiconductor properties, as well as the temperature-induced fluctuations of triboelectric and piezoelectric signals. The humidity signal can correct the changes in the adsorption efficiency of gas molecules on the sensitive membrane surface. Finally, the data processing unit compensates for the monitoring results of transient gas flow rate, dynamic flow rate, and concentration based on temperature and humidity parameters, corrects errors caused by environmental factors, and ultimately achieves reliable synchronous monitoring of transient gas flow rate, dynamic flow rate, temperature, humidity, and concentration in a vacuum environment, meeting the spacecraft's requirement for long-term stable monitoring of gas parameters.

[0069] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A flow detection device with the ability to identify ambient temperature and humidity and gas concentration, characterized in that, Includes a tracheal pressure distribution section and a gas flow monitoring section; The pressure-splitting section of the airway includes an airflow pipe (1) and a pressure-splitting hole (2). The pressure-splitting hole (2) is embedded in the center of the inner wall of the airflow pipe (1). The diameter of the pressure-splitting hole (2) is 2 to 6 mm. The pressure-splitting hole (2) is used to dissipate the airflow in the airflow pipe (1) to the outside. The pressure-splitting hole (2) is connected to the gas flow monitoring section through a flexible air tube (3). The flexible air tube (3) is used to stably introduce the dissipated gas into the gas flow monitoring section. The gas flow monitoring section includes symmetrically arranged cavities (4), contact layer (6), multimodal sensor group (9) and four-level sealing system. The symmetrically arranged cavities (4) are fastened together by long screws (16). The four-level sealing system includes a hard sealing ring (17), a rubber ring (18), a sponge pad (19) and an adhesive filling layer. The hard sealing ring (17), rubber ring (18) and sponge pad (19) are arranged in sequence at the connection part of the cavity (4) and are sealed with adhesive filling to prevent gas leakage in the cavity (4). The inner wall of the cavity (4) is provided with a groove with a depth of 0.1 to 0.5 mm. A copper film (5) is attached to the groove. The contact layer (6) is composed of a multi-layer structure. The first layer is a triboelectric layer (7) made of polytetrafluoroethylene (PTFE) polymer. The second layer is a piezoelectric layer (8) made of polyvinylidene fluoride (PVDF) material. The multimodal sensor group (9) is disposed on the high-voltage side of the contact layer (6) or on the groove wall of the cavity (4) on the high-voltage side. The multimodal sensor group (9) includes a temperature sensor (10), a humidity sensor (11) and an electrochemical sensor (12). The electrochemical sensor (12) is a heterogeneous biofilm sensor, and the electrochemical sensor (12) can be self-powered by the voltage generated by the piezoelectric layer (8).

2. The flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The flexible air tube (3) is made of silicone rubber or polyurethane elastomer, and the inner diameter of the flexible air tube (3) matches the diameter of the pressure dividing hole (2).

3. The flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The thickness of the copper film (5) is 10-50 μm, and the surface roughness Ra of the copper film (5) is ≤0.5 μm.

4. A flow detection device with ambient temperature and humidity and gas concentration recognition as described in claim 1, characterized in that, The triboelectric layer (7) and the piezoelectric layer (8) are compositely formed by electrospinning process, and the thickness ratio of the triboelectric layer (7) to the piezoelectric layer (8) is 1:0.5-1.

5.

5. A flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The electrochemical sensor (12) includes a substrate (13), an electrode (14), and a modification layer (15); the substrate (13) is made of polyimide (PI) or polydimethylsiloxane (PDMS), the electrode (14) is made of a metal conductive material or a carbon-based material, and the modification layer (15) is made of ZnO or ZnS inorganic semiconductor gas-sensitive material.

6. A flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The pressure dividing holes (2) are evenly distributed along the axial direction of the airflow pipe (1), and the hole spacing of the pressure dividing holes (2) is 5 to 15 mm.

7. A flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The bottom of the groove of the cavity (4) is provided with a gas guiding microstructure, which is a strip-shaped protrusion with a width of 0.05 to 0.2 mm.

8. A flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The polarization direction of the piezoelectric layer (8) is perpendicular to the airflow direction, and the polarization intensity of the piezoelectric layer (8) is 30-70mV / N.

9. A flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The signal output terminals of the temperature sensor (10) and the humidity sensor (11) are both connected to the data processing unit, which is used to compensate for the interference of environmental parameters on the gas monitoring results.

10. A flow detection device with ambient temperature and humidity and gas concentration recognition according to claim 1, characterized in that, The sensitive membrane material of the biomembrane sensor is functionalized nanofiber, and the surface of the sensitive membrane is loaded with gas-specific recognition sites. The detection limit of the biomembrane sensor is as low as 10 ppm.

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