An adaptive liquid supply near-zero ozone plasma activation sterilization unit, device and operation control method

Abstract

The application discloses a kind of self-adapting liquid supply near-zero ozone plasma activation sterilization unit, device and operation control method, including self-liquid water vapor condensation module, condensate collection and capillary self-adapting liquid supply module, composite wet ground electrode, annular high-voltage electrode, airflow driving module.Cold condensate collection and capillary self-adapting liquid supply module adopts wedge-shaped hydrophilic collection area, hydrophilic porous transport layer and the structure of hydrophobic lateral resistance flow layer, and hydrophilic porous transport layer forms liquid storage transport section and capillary flow limiting section along the direction of transport;Composite wet ground electrode adopts porous wetting layer to cover the exposed metal surface of metal tip in the axial projection range of annular high-voltage electrode central through-hole.The application realizes liquid supply self-adapting adjustment using capillary transport nozzle structure, and continuously outputs hydroxyl radical plasma activated water mist without relying on external water source, which can be widely applied to air sterilization, purification and conditioning system, as well as food preservation sterilization, deodorization and other fields of human environment.

Description

Technical Field

[0001] This invention belongs to the field of low-temperature plasma application technology, specifically relating to a near-zero ozone plasma activation sterilization unit, device, and operation control method with adaptive liquid supply. Background Technology

[0002] Low-temperature plasma can activate liquids and form various active components under ambient temperature conditions, and has wide applications in air sterilization, food preservation and sterilization, and deodorization of living environments. Existing plasma activation devices mostly rely on liquid storage containers, pumping mechanisms, or external pipelines for liquid supply, resulting in complex structures that are not conducive to miniaturization and independent operation. While using air vapor condensation as a liquid source can reduce reliance on external water supply, the amount of condensate generated is easily affected by ambient temperature and humidity, cold end temperature, and airflow conditions, making it difficult to continuously match with the consumption of the electric jet.

[0003] During the formation of plasma-activated water mist, insufficient liquid supply can lead to interruption of the liquid film at the tip, disappearance of the liquid cone, or intermittent spraying, while excessive liquid supply can easily cause liquid accumulation, droplet shedding, and discharge fluctuations. At the same time, the condensate is prone to stagnation and disordered migration on the condensation surface, making it difficult to continuously and directionally deliver it to the electrode tip.

[0004] Furthermore, changes in device orientation alter the direction of liquid transport, affecting tip wetting and Taylor cone stability, and further influencing ozone byproduct formation. Therefore, existing technologies still need to address issues such as directional condensate collection, matching self-supplying condensate with atomization consumption, stable operation across multiple orientations, and near-zero ozone synergistic control. Summary of the Invention

[0005] To address the problems of existing plasma activation devices, such as reliance on external liquid sources, discontinuous condensate delivery, difficulty in matching liquid supply with electrojet consumption, and the tendency for tip liquid film fluctuations to cause Taylor cone instability and increase ozone byproducts, this invention proposes a near-zero ozone plasma activation and sterilization unit, device, and operation control method with adaptive liquid supply. The condensate is directionally collected through a wedge-shaped hydrophilic region and then enters the storage and transport section and the capillary flow-limiting section. This allows for continuous liquid replenishment when the tip of the composite wetting electrode is low and limits excessive liquid supply when the liquid at the tip is sufficient. Simultaneously, the liquid film at the tip and edge of the composite wetting electrode covers the metal tip region corresponding to the central through-hole of the annular high-voltage electrode. This ensures that the non-uniform electric field preferentially acts on the liquid film and porous wetting layer at the tip of the composite wetting electrode, maintaining the output of activated water mist and suppressing non-target gas phase discharge.

[0006] To achieve the above objectives, the technical solution of the present invention is: a near-zero ozone plasma activation sterilization unit with adaptive liquid supply, comprising: The self-supplying liquid vapor condensation module includes a condensation metal substrate, a semiconductor refrigeration chip, and heat dissipation fins. The cold end of the semiconductor refrigeration chip is connected to the condensation metal substrate, and the hot end is connected to the heat dissipation fins, which are used for condensation liquid extraction and hot end heat dissipation. A condensate collection and capillary adaptive liquid supply module is disposed on the surface of the condensing metal substrate. The module includes a wedge-shaped hydrophilic collection area, a hydrophobic isolation area, a hydrophilic porous transport layer, and a hydrophobic lateral flow barrier layer. The surface of the hydrophobic isolation area is provided with multiple wedge-shaped hydrophilic collection areas arranged at intervals along a predetermined direction, and adjacent wedge-shaped hydrophilic collection areas are separated by the hydrophobic isolation area. Each wedge-shaped hydrophilic collection area generates liquid collection effect by its own hydrophilicity and wedge structure, which can directionally collect the dispersed condensate to the liquid inlet end of the hydrophilic porous transport layer. The hydrophilic porous transport layer forms a liquid storage transport section and a capillary flow restriction section in sequence along the condensate transport direction. The hydrophobic lateral flow barrier layer covers the outer peripheral side of the hydrophilic porous transport layer, while keeping the liquid inlet end and liquid outlet end of the hydrophilic porous transport layer exposed, which can limit the lateral leakage, disordered spread and reverse migration of condensate, and guide the condensate to be directionally transported from the liquid inlet end to the liquid outlet end.

[0007] The composite wetting grounding electrode and the annular high-voltage electrode, and the annular high-voltage electrode spaced apart from the tip of the composite wetting grounding electrode. The annular high-voltage electrode is located in front of the composite wetting grounding electrode and spaced apart from its tip. After applying high voltage between it and the composite wetting grounding electrode, a non-uniform electric field is formed acting on the liquid film, causing the continuous liquid film to form a Taylor cone and generate an electric jet. The electric jet is atomized and output through the central through hole of the annular high-voltage electrode, and is activated to form plasma-activated water mist in the discharge area.

[0008] Furthermore, the composite wetting grounding electrode is composed of a self-supplying liquid vapor condensation module, a condensate collection and capillary adaptive liquid supply module, and a metal grounding electrode substrate. The composite wetting grounding electrode includes a metal grounding electrode tip and a tip porous wetting layer covering the outer surface of the metal grounding electrode tip. The metal grounding electrode tip and the tip porous wetting layer form a composite wetting grounding tip. The tip porous wetting layer is in communication with the liquid outlet of the hydrophilic porous liquid delivery layer, so that the condensate is transported to the metal grounding electrode tip and forms a continuous liquid film.

[0009] Furthermore, the pointed porous wetting layer at least covers the exposed metal surface of the metal grounding electrode tip within the axial projection range of the central through hole of the annular high-voltage electrode, so that the high field strength region preferentially acts on the liquid film and Taylor cone, reducing non-target gas phase discharge between the exposed metal surface and the air.

[0010] Furthermore, the hydrophilic porous transport layer has different pore structures in the liquid storage and transport section and the capillary flow limiting section along the condensate transport direction. The liquid storage and transport section near the condensation metal substrate adopts a larger equivalent pore radius or higher permeability to receive and temporarily store condensate. The capillary flow limiting section near the tip of the metal grounding electrode adopts a smaller equivalent pore radius or lower permeability to improve liquid retention capacity and limit instantaneous liquid supply, thereby reducing the possibility of tip liquid shortage or excessive liquid accumulation.

[0011] Furthermore, the liquid storage and transport sections and capillary flow-limiting sections of the hydrophilic porous transport layer are formed by overlapping different porous materials, local compaction, impregnation treatment, or continuous pore gradient.

[0012] Furthermore, a first water-guiding hole is provided between the condensed metal substrate and the hydrophilic porous transport layer, and a second water-guiding hole is provided between the hydrophilic porous transport layer and the tip porous wetting layer. The first and second water-guiding holes are through holes, slots, or interconnected liquid guiding channels to improve the transport and distribution of condensate inside the porous structure.

[0013] Furthermore, the static water contact angle of the wedge-shaped hydrophilic collection zone is 5° to 35°, and the static water contact angle of the hydrophobic isolation zone is 120° to 170°; the equivalent pore radius of the hydrophilic porous transport layer is 0.1 to 25 μm, and the solid-liquid contact angle is 10° to 30°.

[0014] Furthermore, the axial distance between the tip of the metal grounding electrode and the annular high-voltage electrode is 2–15 mm, the wetting diameter of the tip of the metal grounding electrode is 100–500 μm, and the AC or DC high voltage applied by the annular high-voltage electrode is 3–6 kV.

[0015] Secondly, the present invention also provides a near-zero ozone plasma activation sterilization device with adaptive liquid supply, including the plasma activation sterilization unit mentioned above, and an airflow drive module. The airflow drive module is configured inside the device housing and drives external humid gas to enter from the air inlet, pass through the area where the heat dissipation fins and the condensation metal substrate are located, and then exit from the air outlet. This is used to realize heat dissipation of the hot end of the semiconductor cooling chip, renewal of humid gas, and condensation water collection.

[0016] Furthermore, when multiple plasma activation sterilization units are set, the multiple plasma activation sterilization units are distributed at equal intervals around the central axis of the device, and the tip of each metal ground electrode faces the central through hole of the corresponding annular high voltage electrode. The atomization axes of adjacent plasma activation sterilization units extend in mutually separated directions to reduce mutual interference between adjacent Taylor cones and activated water mist.

[0017] Thirdly, the present invention also provides an operation control method for a near-zero ozone plasma activation sterilization device with adaptive liquid supply, comprising the following steps: S1. First, start the airflow drive module and the semiconductor cooling chip; S2. The condensate passes sequentially through the wedge-shaped hydrophilic collection area, the first water guide hole, the hydrophilic porous transport layer, the second water guide hole and the porous wetting layer, and reaches the tip of the metal grounding electrode. S3. After a continuous liquid film is formed at the tip, apply a high voltage to the annular high-voltage electrode. S4. When stopping operation, first disconnect the high-voltage power supply, then stop the semiconductor cooling chip and the airflow drive module.

[0018] The beneficial effects of this invention are as follows: (1) Expand the stable operating range of Taylor cone. After adopting the composite wetting ground electrode, the range of liquid supply flow and meniscus thickness for stable operation of Taylor cone is significantly expanded, the device's adaptability to changes in liquid supply and tip liquid film is improved, and the disappearance of cone, intermittent spraying, droplet accumulation and multi-cone phenomenon caused by insufficient or excessive liquid supply are effectively reduced.

[0019] (2) Reduce ozone byproducts. Under different operating conditions such as insufficient liquid supply, stable liquid supply and excessive liquid supply, the composite wetted grounding electrode can significantly reduce the ozone concentration increment and maintain it in the near-zero ozone range. Thus, while maintaining the stable output of the Taylor cone and activated water mist, it effectively suppresses non-target gas phase discharge between the exposed metal tip and the air.

[0020] (3) Balancing ozone control and sterilization effects. Under the operating state of controlling ozone byproducts, the device of the present invention can still stably form and output plasma-activated water mist, so that active components such as hydroxyl radicals are transported to the target surface with micro-droplets and produce effective sterilization effect, avoiding the reliance on increasing the concentration of gas phase ozone to enhance the sterilization effect, thus balancing the low ozone operation and the sterilization needs of the target surface. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the plasma activation sterilization unit provided in an embodiment of the present invention; Figure 2 This is a structural diagram of the plasma activation sterilization unit (excluding the high-voltage ring electrode) provided in an embodiment of the present invention; Figure 3 This is a side view of the plasma activation sterilization unit provided in the embodiment of the present invention; Figure 4 yes Figure 3 AA-direction cross section; Figure 5 This is a plan view of the plasma activation sterilization unit provided in the embodiment of the present invention from the front view direction; Figure 6 yes Figure 5 BB-direction cross-section; Figure 7 , Figure 8 These are cross-sectional structural diagrams of the plasma activation sterilization device provided in the embodiments of the present invention from two different directions; Figure 9 This is a comparison chart of the stable operating range of the Taylor cone device of the present invention and the comparative case; Figure 10 This is a comparison chart of the ozone control effects of the device of the present invention and the comparative case; Figure 11 This is a diagram illustrating the disinfection effect of the device of the present invention on Escherichia coli; Figure 12 This is a comparison chart of the generation rate of hydroxyl radicals between the device of the present invention and a comparative case; Figure label: 100. Plasma activation sterilization unit; 101. Composite wetting grounding electrode; 102. Ring high voltage electrode; 201. Condensing metal substrate; 202. Semiconductor cooling chip; 203. Heat dissipation fins; 301. Wedge-shaped hydrophilic collection area; 302. Hydrophobic isolation area; 303. Hydrophilic porous transport layer; 304. Hydrophobic lateral flow barrier layer; 305. Porous wetting layer; 401. First water guide hole; 402. Second water guide hole; 501. Composite wetting grounding tip; 502. Metal grounding electrode tip; 602. Airflow drive module; 603. Air inlet; 604. Air outlet. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the following descriptions of directions such as above, below, inside, and outside are only used to illustrate the relative positional relationships between the components shown in the drawings and do not constitute a limitation on the installation direction and usage posture of the device.

[0023] This embodiment provides a near-zero ozone plasma activation sterilization device with adaptive liquid supply. The device includes multiple plasma activation sterilization units and an airflow drive module. The plasma activation sterilization unit includes a self-supplying water vapor condensation module, a condensate collection and capillary adaptive liquid supply module, a composite wetting grounding electrode, and an annular high-voltage electrode. The self-supplying water vapor condensation module is used to obtain condensate from the humid gas. The condensate collection and capillary adaptive liquid supply module is used to collect the dispersed condensate and deliver it to the tip of the atomizing electrode. The plasma activation sterilization unit is used to form a Taylor cone of liquid film at the tip and output plasma-activated water mist. The airflow drive module is used to guide the flow of humid gas, cool the heat-conducting fins, and complete the internal ventilation of the device.

[0024] Example 1: like Figure 1As shown, the plasma activation sterilization unit 100 includes a composite wetting ground electrode 101 and an annular high-voltage electrode 102. The composite wetting ground electrode 101 is composed of a self-supplying liquid vapor condensation module, a condensate collection and capillary adaptive liquid supply module, and a metal ground electrode substrate 403. The composite wetting ground electrode 101 includes a metal ground electrode tip 502 and a tip porous wetting layer 305 covering the outer surface of the metal ground electrode tip 502. The tip porous wetting layer 305 is in liquid communication with the liquid outlet of the hydrophilic porous liquid delivery layer 303, so that the condensate is delivered to the metal ground electrode tip 502 and forms a continuous liquid film.

[0025] An annular high-voltage electrode 102 is disposed in front of the composite wetting ground electrode 101. Its central through hole is opposite to the atomization axis of the composite wetting ground electrode 101. After applying high voltage between it and the composite wetting ground electrode 101, a non-uniform electric field is formed acting on the liquid film, causing the continuous liquid film to form a Taylor cone and generate an electric jet. The electric jet is atomized and output through the central through hole of the annular high-voltage electrode and activated to form plasma-activated water mist in the discharge region.

[0026] like Figure 2 As shown, the self-supplying liquid vapor condensation module includes a condensing metal substrate 201, a thermoelectric cooler 202, and heat dissipation fins 203. The condensing metal substrate 201 is connected to the cold end of the thermoelectric cooler 202, and the heat dissipation fins 203 are connected to the hot end of the thermoelectric cooler 202. When the thermoelectric cooler 202 is energized, at least a portion of the surface of the condensing metal substrate 201 is lower than the dew point temperature of the humid gas, thereby forming condensate on its surface.

[0027] like Figure 3 As shown, the condensate collection and capillary adaptive liquid supply module includes a wedge-shaped hydrophilic collection region 301, a hydrophobic isolation region 302, a hydrophilic porous transport layer 303, a hydrophobic lateral flow-blocking layer 304, and a porous wetting layer 305. Multiple wedge-shaped hydrophilic collection regions 301 are disposed on the surface of the condensation metal substrate 201 and are separated from each other by the hydrophobic isolation regions 302. The boundary spacing of the wedge-shaped hydrophilic collection regions 301 varies along their extension direction, and their collection ends are connected to the liquid inlet end of the hydrophilic porous transport layer 303, used to directionally collect the dispersed condensate to the liquid inlet end.

[0028] In this embodiment, the static water contact angle of the wedge-shaped hydrophilic collection region 301 is 5°–35°, and the static water contact angle of the hydrophobic isolation region 302 is 120°–170°; the equivalent pore radius of the hydrophilic porous transport layer 303 is 0.1–25 μm, and the solid-liquid contact angle is 10°–30°. The hydrophobic lateral flow barrier layer 304 covers the outer peripheral surface of the hydrophilic porous transport layer 303, keeping its inlet and outlet ends exposed to limit lateral leakage, disordered spreading, and reverse migration of condensate.

[0029] The hydrophilic porous transport layer 303 sequentially forms a liquid storage and transport section and a capillary flow-limiting section along the condensate transport direction. The liquid storage and transport section uses a larger equivalent pore radius or higher permeability to receive and temporarily store condensate; the capillary flow-limiting section uses a smaller equivalent pore radius or lower permeability to improve liquid retention capacity and limit instantaneous liquid supply. The two sections can be formed by overlapping different porous materials, or a continuous pore gradient can be formed through local compaction, impregnation treatment, or thickness variation.

[0030] like Figure 4 As shown, a first water-guiding hole 401 is provided between the condensed metal substrate 201 and the hydrophilic porous transport layer 303, and a second water-guiding hole 402 is provided between the hydrophilic porous transport layer 303 and the porous wetting layer 305. The first water-guiding hole 401 guides the condensate collected in the wedge-shaped hydrophilic collection area 301 into the hydrophilic porous transport layer 303, and the second water-guiding hole 402 guides the condensate into the porous wetting layer 305. The first water-guiding hole 401 and the second water-guiding hole 402 can be through holes, slots, or interconnected liquid guiding channels.

[0031] like Figure 5 , Figure 6 As shown, the composite wetting grounding tip 501 includes a metal grounding electrode tip 502 and a porous wetting layer 305 covering its outer side. The porous wetting layer 305 communicates with the liquid outlet end of the hydrophilic porous transport layer 303 and at least covers the exposed metal surface within the axial projection range of the central through hole of the annular high-voltage electrode 102. After the condensate reaches the porous wetting layer 305, it forms a continuous liquid film on the surface of the metal grounding electrode tip 502.

[0032] The metal grounding electrode tip 502 is connected to the grounding terminal, and the annular high-voltage electrode 102 is connected to the high-voltage output terminal of the high-voltage power supply. The axial distance between them is 2–15 mm, the tip wetting diameter is 100–500 μm, and the applied voltage is 3–6 kV. After energization, the non-uniform electric field preferentially acts on the continuous liquid film, causing the liquid film to form a Taylor cone and an electric jet; the electric jet is atomized and output through the central through-hole of the annular high-voltage electrode 102, and forms plasma-activated water mist in the discharge region. The porous wetting layer 305 forms a liquid cover over the high field strength region, thereby reducing non-target gas phase discharge between the exposed metal surface and the air.

[0033] When the liquid at the tip is consumed due to atomization, the liquid content at the tip decreases, the capillary pressure difference increases, and the condensate in the liquid storage and transport section is replenished to the tip through the capillary flow restriction section. When the liquid at the tip tends to be sufficient, the transport resistance of the capillary flow restriction section and the circumferential constraint of the hydrophobic lateral flow barrier 304 limit the continued liquid supply, so that the liquid replenishment at the tip is passively adjusted according to the atomization consumption state.

[0034] like Figure 7 , Figure 8As shown, the near-zero ozone adaptive liquid supply plasma activation sterilization device 600 includes one to six plasma activation sterilization units 100 and an airflow drive module 602. Multiple plasma activation sterilization units 601 are spaced apart around the central axis of the device, with adjacent atomization axes extending in mutually separated directions to reduce interference between adjacent Taylor cones and activated water mist.

[0035] An air inlet 603 is located at the lower part of the housing or at the lower side wall, and an air outlet 604 is located at the upper part of the housing. The airflow drive module 602 drives external humid gas to enter through the air inlet 603 and flow through the area where the heat dissipation fins 203 and the condensation metal substrate 201 are located at a flow rate of 0.1 to 0.9 m / s, and then discharges through the air outlet 604, thereby simultaneously realizing heat dissipation at the hot end, renewal of humid gas, and condensation supply.

[0036] When the device starts, the airflow drive module 602 and the thermoelectric cooler 202 are activated first. The condensate sequentially passes through the wedge-shaped hydrophilic collection area 301, the first water guide hole 401, the hydrophilic porous transport layer 303, the second water guide hole 402, and the porous wetting layer 305, reaching the tip 502 of the metal grounding electrode. After a continuous liquid film forms at the tip, a high voltage is applied to the annular high-voltage electrode 102. When stopping operation, the high-voltage power supply is cut off first, and then the thermoelectric cooler 202 and the airflow drive module 602 are stopped.

[0037] Example 2: Comparison of Taylor cone stability range A composite wetting grounding electrode was used as an example, and a bare metal grounding electrode after removing the hydrophilic porous transport layer 303, the hydrophobic lateral flow-blocking layer 304, and the porous wetting layer 305 was used as a comparative example. Under the same conditions of voltage, electrode spacing, environmental conditions, and observation time, the liquid supply flow rate and meniscus thickness were changed, and the ability to continuously maintain a single Taylor cone and stably output water mist was used as the criterion for stable operation.

[0038] like Figure 9 As shown, the stable region of the bare metal grounding electrode has a projection range of 0.21–0.42 mL / h in the direction of liquid supply flow and a projection range of 160–315 μm in the direction of meniscus thickness; the corresponding ranges for the composite wetting grounding electrode are 0.15–0.80 mL / h and 100–470 μm, respectively, indicating that the composite capillary infusion structure can simultaneously improve the device's adaptability to insufficient liquid supply, excessive liquid supply, and changes in the liquid film at the tip.

[0039] Example 3: Comparison of Ozone Control Effects Before testing, the porous wetting layer 305 of the composite wetting grounding electrode was brought to a uniform initial wetting state. Under the same conditions of voltage, electrode spacing, detection position, and detection time, three operating conditions were set up: insufficient liquid supply, stable liquid supply, and excessive liquid supply. The ozone concentration increment generated by the composite wetting grounding electrode and the bare metal grounding electrode was detected.

[0040] like Figure 10 As shown, when the liquid supply flow rate at the tip of the plasma-activated sterilization unit was 0, 0.325 mL / h, and 0.8 mL / h, the ozone concentration increments for the bare metal grounding electrode were 125 ppb, 73 ppb, and 114 ppb, respectively, and for the composite wetted grounding electrode, they were 12 ppb, 24 ppb, and 27 ppb, respectively. The results indicate that the continuous liquid film formed by the porous wetting layer allows the high-field region to preferentially act on the liquid and the Taylor cone, reducing the possibility of gas-phase ionization at the exposed metal tip during liquid supply fluctuations.

[0041] Example 4: Efficacy of Escherichia coli inactivation like Figure 11 As shown, to verify the bactericidal effect of the activated water mist output by the device, *E. coli* plates were used as the test object, with an untreated control group and experimental groups treated for different durations. The experimental groups were placed within the effective coverage area of ​​the activated water mist and treated under conditions where the Taylor cone remained stable and ozone byproducts were suppressed. After treatment, the control and experimental groups were incubated under the same conditions, and the sterilization rate was calculated based on the number of colonies in each group. The experimental results show that as the activated water mist treatment time increased, the number of colonies in the experimental groups gradually decreased, and the sterilization rate showed an increasing trend. This result indicates that the device, under controlled ozone byproduct operation, can still utilize plasma-activated water mist to produce a bactericidal effect on the target surface, making it suitable for applications requiring no external liquid source, continuous atomization, near-zero ozone emissions, and room temperature sterilization.

[0042] Example 5: Effect on the generation rate of hydroxyl radicals (·OH) Before testing, the porous wetting layer 305 of the composite wetting grounding electrode was brought to a uniform initial wetting state. Under the same conditions of voltage, electrode spacing, detection position, and detection time, three operating conditions were set up: insufficient liquid supply, stable liquid supply, and excessive liquid supply. The generation rate of hydroxyl radicals generated by the composite wetting grounding electrode and the bare metal grounding electrode was measured and calculated.

[0043] like Figure 12As shown, when the liquid supply flow rate at the tip of the plasma-activated sterilization unit is insufficient (0 mL / h), stable (0.325 mL / h), and excessive (0.8 mL / h), the hydroxyl radical (·OH) generation rates of the bare metal grounding electrode (comparative case) are 0 nmol / min, 0.07 nmol / min, and 0.03 nmol / min, respectively, and those of the composite wetting grounding electrode (implementation case) are 0 nmol / min, 0.10 nmol / min, and 0.08 nmol / min, respectively.

[0044] The results show that, under conditions with liquid supply (0.325 mL / h and 0.8 mL / h), the rate of hydroxyl radicals generated by the composite wetting grounding electrode is significantly higher than that of the bare metal grounding electrode. The porous wetting layer, by maintaining a uniform and stable liquid film, enhances the activation efficiency of the discharge plasma on the liquid and the stability of the Taylor cone formation, thereby significantly promoting the generation of (·OH). Even when excessive liquid supply leads to a decrease in the overall generation rate, the composite wetting electrode can still maintain a high (·OH) yield and adaptability to different operating conditions.

[0045] The foregoing has provided a detailed description of a near-zero ozone adaptive liquid supply plasma activation sterilization unit, device, and operation control method provided by embodiments of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. It should be understood that the above embodiments are only for illustrating the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, or combinations made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A near-zero ozone plasma activation sterilization unit with adaptive liquid supply, characterized in that, include: The self-supplying liquid vapor condensation module includes a condensation metal substrate (201), a semiconductor refrigeration chip (202), and heat dissipation fins (203). The cold end of the semiconductor refrigeration chip (202) is connected to the condensation metal substrate (201), and the hot end is connected to the heat dissipation fins (203), which are used for condensation liquid extraction and hot end heat dissipation. A condensate collection and capillary adaptive liquid supply module is disposed on the surface of the condensation metal substrate (201). The module includes a wedge-shaped hydrophilic collection area (301), a hydrophobic isolation area (302), a hydrophilic porous transport layer (303), and a hydrophobic lateral flow barrier layer (304). The surface of the hydrophobic isolation area (302) is provided with a plurality of wedge-shaped hydrophilic collection areas (301) arranged at intervals along a predetermined direction, and adjacent wedge-shaped hydrophilic collection areas (301) are separated by the hydrophobic isolation area (302). Each wedge-shaped hydrophilic collection area (301) relies on its own hydrophilicity to connect with the wedge. The structure generates a liquid aggregation effect, which can directionally collect the dispersed condensate to the inlet end of the hydrophilic porous transport layer (303); the hydrophilic porous transport layer (303) forms a liquid storage transport section and a capillary flow restriction section in sequence along the condensate transport direction; the hydrophobic lateral flow barrier layer (304) covers the outer peripheral side of the hydrophilic porous transport layer (303), while keeping the inlet end and outlet end of the hydrophilic porous transport layer (303) exposed, which can limit the lateral leakage, disordered spread and reverse migration of condensate, and guide the condensate to be transported in a directional manner from the inlet end to the outlet end; The composite wetting grounding electrode (101) and the annular high voltage electrode (102), and the annular high voltage electrode (102) spaced apart from the tip of the composite wetting grounding electrode (101) are located in front of the composite wetting grounding electrode (101) and spaced apart from its tip. After applying high voltage between the composite wetting grounding electrode (101), a non-uniform electric field is formed acting on the liquid film, causing the continuous liquid film to form a Taylor cone and generate an electric jet. The electric jet is atomized and output through the central through hole of the annular high voltage electrode and activated to form plasma activated water mist in the discharge area.

2. The near-zero ozone plasma activation sterilization unit with adaptive liquid supply according to claim 1, characterized in that, The composite wetting grounding electrode (101) is composed of a self-supplying liquid vapor condensation module, a condensate collection and capillary adaptive liquid supply module, and a metal grounding electrode substrate (403). The composite wetting grounding electrode (101) includes a metal grounding electrode tip (502) and a tip porous wetting layer (305) covering the outer surface of the metal grounding electrode tip (502). The metal grounding electrode tip (502) and the tip porous wetting layer (303) form the composite wetting grounding tip (501). The tip porous wetting layer (305) is in liquid communication with the liquid outlet of the hydrophilic porous liquid delivery layer (303), so that the condensate is transported to the metal grounding electrode tip (502) and forms a continuous liquid film.

3. The near-zero ozone plasma activation sterilization unit with adaptive liquid supply according to claim 2, characterized in that, The pointed porous wetting layer (305) at least covers the exposed metal surface of the metal grounding electrode tip (502) within the axial projection range of the central through hole of the annular high voltage electrode (102).

4. The near-zero ozone plasma activation sterilization unit with adaptive liquid supply according to claim 2, characterized in that, The hydrophilic porous transport layer (303) is formed by overlapping different porous materials, local compaction, impregnation treatment or continuous pore gradient. The hydrophilic porous transport layer (303) has different pore structures for the liquid storage and transport section and the capillary flow limiting section along the condensate transport direction. The pores of the liquid storage and transport section are larger than those of the capillary flow limiting section. The liquid storage and transport section near the condensate metal substrate (201) is used to receive and temporarily store condensate. The capillary flow limiting section near the tip (502) of the metal grounding electrode is used to improve the liquid retention capacity and limit the instantaneous liquid supply.

5. The near-zero ozone plasma activation sterilization unit with adaptive liquid supply according to claim 1, characterized in that, A first water guide hole (401) is provided between the condensed metal substrate (201) and the hydrophilic porous transport layer (303), and a second water guide hole (402) is provided between the hydrophilic porous transport layer (303) and the tip porous wetting layer (305). The first water guide hole (401) and the second water guide hole (402) are through holes, slots or interconnected liquid guiding channels.

6. The near-zero ozone plasma activation sterilization unit with adaptive liquid supply according to claim 1, characterized in that, The static water contact angle of the wedge-shaped hydrophilic collection region (301) is 5° to 35°, and the static water contact angle of the hydrophobic isolation region (302) is 120° to 170°; the equivalent pore radius of the hydrophilic porous transport layer (303) is 0.1 to 25 μm, and the solid-liquid contact angle is 10° to 30°.

7. The near-zero ozone plasma activation sterilization unit with adaptive liquid supply according to claim 2, characterized in that, The axial distance between the metal grounding electrode tip (502) and the annular high voltage electrode (102) is 2 to 15 mm, the wetting diameter of the metal grounding electrode tip (502) is 100 to 500 μm, and the AC or DC high voltage applied by the annular high voltage electrode (102) is 3 to 6 kV.

8. A near-zero ozone plasma activation sterilization device based on the adaptive liquid supply of the plasma activation sterilization unit according to any one of claims 1-7, characterized in that, It includes a plasma activation sterilization unit (100) and an airflow drive module (602). The airflow drive module (602) is configured inside the device housing and drives external humid gas to enter from the air inlet (603), pass through the area where the heat dissipation fins (203) and the condensation metal substrate (201) are located, and then exit from the air outlet (604). It is used to realize heat dissipation of the hot end of the semiconductor cooling chip (202), renewal of humid gas, and condensation water collection.

9. The near-zero ozone plasma activation sterilization device with adaptive liquid supply according to claim 8, characterized in that, When multiple plasma-activated sterilization units (100) are set, the multiple plasma-activated sterilization units (100) are distributed at equal intervals around the central axis of the device, and the tip (502) of each metal ground electrode faces the central through hole of the corresponding annular high voltage electrode (102). The atomization axes of adjacent plasma-activated sterilization units (100) extend in mutually separated directions.

10. A method for operating and controlling a near-zero ozone plasma activation sterilization device with adaptive liquid supply as described in claim 8, characterized in that, Includes the following steps: S1. First, start the airflow drive module (602) and the semiconductor cooling chip (202). S2. The condensate passes through the wedge-shaped hydrophilic collection area (301), the first water guide hole (401), the hydrophilic porous transport layer (303), the second water guide hole (402) and the porous wetting layer (305) in sequence, and reaches the tip of the metal grounding electrode (502). S3. After a continuous liquid film is formed at the tip, apply a high voltage to the annular high voltage electrode (102); S4. When stopping operation, first cut off the high-voltage power supply, and then stop the semiconductor cooling chip (202) and the airflow drive module (602).

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