Low-temperature plasma and ultraviolet rapid synergistic laboratory space sterilization system

Abstract

The invention relates to the technical field of disinfection and sterilization, and discloses a low-temperature plasma and ultraviolet rapid synergistic laboratory space sterilization system. The invention aims to solve the problems of many sterilization dead angles, limited effect on stubborn microorganisms, difficulty in control of ozone byproducts, low energy efficiency and the like in a closed laboratory space in the existing chemical fumigation, single ultraviolet or simple combination mode. The system comprises an annular array type plasma generation module, a rotatable multidirectional ultraviolet radiation module, an intelligent environment perception and control system and a directional induction airflow system. The method comprises the following steps: initializing a system and loading a control program; plasma pretreatment is executed; entering an ultraviolet and plasma synergistic sterilization stage, and generating a light-plasma catalytic effect by utilizing the space-time complementation of rotating ultraviolet and array plasma; and finally carrying out ozone decomposition and safety monitoring. By the adoption of the technical scheme, rapid, uniform and dead-corner-free efficient sterilization can be achieved, the inactivation rate of stubborn microorganisms is remarkably increased, it is ensured that the ozone concentration is lower than a safety threshold value in the whole process through intelligent closed-loop control, and meanwhile system energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of air and surface disinfection and sterilization technology, and in particular to a space sterilization system for laboratory environments that combines low-temperature plasma and ultraviolet radiation for rapid synergistic sterilization. Background Technology

[0002] In biosafety laboratories, cell culture rooms, and molecular biology experimental sites, where extremely stringent environmental cleanliness requirements exist, microbial contamination remains a core risk factor threatening the reliability of experimental results and the health of personnel. To ensure a sterile environment, existing sterilization technologies primarily include chemical fumigation, high-temperature and high-pressure treatment, and ultraviolet irradiation. However, chemical fumigation has inherent drawbacks such as toxic residues, strong equipment corrosivity, and long ventilation cycles; high-temperature and high-pressure treatment is only suitable for heat-resistant equipment and cannot be used for overall space disinfection; and single-mode ultraviolet irradiation is limited by the linear propagation characteristics of light, making it difficult to cover shaded areas, and its inactivation efficiency against highly resistant microorganisms such as spores and viruses is low, failing to meet the rapid, comprehensive sterilization needs of high-cleanliness laboratories.

[0003] Low-temperature plasma technology, due to its ability to efficiently generate broad-spectrum bactericidal factors such as reactive oxygen species, reactive nitrogen species, and free radicals at ambient temperature and pressure, has been introduced into the field of space disinfection in recent years. However, when plasma is used alone, its effective range is limited by the discharge area, its energy consumption is high, and it is prone to producing ozone byproducts. If not effectively controlled, it will exceed the indoor air quality safety limits. Although some studies have attempted to combine plasma with ultraviolet technology to propose pipeline-type composite disinfection devices or mobile plasma-ultraviolet robots, the former focuses on fluid channel processing, and the latter adopts a fixed-sequence alternating working mode. Neither has been systematically optimized for the three-dimensional space of a closed laboratory, lacks synergistic design of plasma and ultraviolet at the levels of temporal overlap, spatial complementarity, and energy coupling, and has not integrated a closed-loop intelligent control mechanism for ozone concentration, ultraviolet intensity, and airflow organization.

[0004] Current technologies therefore face multiple contradictions: on the one hand, they need to achieve rapid, uniform, and thorough sterilization across the entire area; on the other hand, they must strictly control ozone emissions and avoid secondary pollution. They also need to improve the inactivation efficiency against stubborn microorganisms (such as spores) while balancing system energy efficiency and operational safety. Especially in practical applications, the lack of an integrated system capable of dynamically sensing environmental parameters, adaptively adjusting multi-source sterilization factors, and achieving a "photo-plasma catalysis" enhancement effect makes it difficult for existing solutions to complete log6-level efficient sterilization of standard laboratory spaces larger than 10 m³ within 10–15 minutes. Therefore, there is an urgent need to construct a rapid synergistic sterilization system combining low-temperature plasma and ultraviolet light for enclosed laboratory scenarios. This system should overcome the bottlenecks in synergy, coverage, safety, and intelligence of existing technologies through the deep integration of a ring plasma array, a rotatable multi-directional ultraviolet module, intelligent feedback control, and directional airflow induction. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a laboratory space sterilization system that combines low-temperature plasma with rapid ultraviolet radiation, effectively solving the problems in the background technology. Existing technologies face the contradiction between rapid, comprehensive sterilization and ozone safety control, improving the inactivation efficiency of stubborn microorganisms while considering system energy efficiency and safety. In particular, they lack an integrated system that can dynamically sense the environment, adaptively adjust multi-source sterilization factors, and achieve a "photo-plasma catalysis" enhancement effect.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In one aspect, a laboratory space sterilization system combining low-temperature plasma and ultraviolet rapid synergy, comprising the following components: A ring-array plasma generation module, consisting of multiple dielectric barrier discharge type low-temperature plasma generation units installed along the edge of the laboratory ceiling or the upper part of the four walls, is used to form a highly reactive particle cloud at the top of the space. A rotatable multi-directional ultraviolet radiation module, mounted on a lifting and rotating mechanism above the central area of ​​the laboratory, includes at least one set of deep ultraviolet LED arrays and one set of UVC mercury lamps. This ultraviolet radiation module can rotate 360° around its vertical axis and its height can be adjusted vertically. An intelligent environmental sensing and control system includes an ozone sensor, an ultraviolet intensity sensor, a temperature and humidity sensor, a particulate matter sensor, and a central controller. The central controller dynamically adjusts the plasma power, ultraviolet radiation intensity, and operating sequence based on sensor data. The system includes a rotation speed and a directional airflow system consisting of a top-supply and bottom-return airflow circulation duct with a built-in HEPA filter. This system guides plasma active particles and ultraviolet light to cover the entire space and accelerate ozone decomposition. A collaborative working mode, executed by the central controller, is also included. After system startup, low-power plasma pretreatment is performed for 5–10 minutes to activate moisture in the air and generate ·OH free radicals. Subsequently, the ultraviolet module starts and rotates, while the plasma module is upgraded to medium-high power. The two modules overlap in time and complement each other in space, forming a "photo-plasma catalysis" effect. After sterilization, the system automatically switches to "ozone decomposition mode," turns off the ultraviolet light, and maintains low-power plasma to work with the catalyst to degrade residual ozone to <0.05 ppm.

[0007] Preferably, the dielectric barrier discharge type low-temperature plasma generating unit in the ring array plasma generating module has a discharge electrode structure consisting of a high-voltage electrode, a ground electrode, and a dielectric layer located therebetween. The high-voltage electrode is connected to a pulse modulation power supply. The output frequency of the pulse modulation power supply is 1–20 kHz, and the duty cycle is continuously adjustable within the range of 10% to 90%. This power supply parameter configuration aims to reduce the heat accumulation in the dielectric layer and optimize the electron energy distribution by controlling the instantaneous power and intermittent period of the discharge energy injection, thereby improving the yield of reactive oxygen species and reactive nitrogen species, while suppressing the excessive generation of nitrogen oxides. Specifically, in a standard rectangular laboratory space, eight generating units are symmetrically arranged at the midpoints of the four edges and the four corners of the ceiling. The active particles generated in the discharge areas of each unit superimpose on each other in the top space and diffuse downwards, forming a uniform initial active particle concentration field.

[0008] Furthermore, the lifting and rotating mechanism of the rotatable multi-directional ultraviolet radiation module is driven by a stepper motor, with its rotation speed infinitely adjustable within the range of 0.5–12 rpm and a lifting stroke of 0.5–2.0 meters. The emission wavelength of the deep ultraviolet LED array is strictly controlled within the range of 265–280 nm, preferably 275 nm, and the light power of a single LED is not less than 50 mW; the main emission wavelength of the UVC mercury lamp is 254 nm. The central controller is configured to control the deep ultraviolet LED array and the UVC mercury lamp to operate in alternating lighting or synchronous full-power mode. When using the alternating lighting mode, the switching cycle is 30–120 seconds, which helps to balance the thermal management of the light source and extend the device life. In particular, the characteristic absorption spectrum of ozone molecules by ultraviolet light at a wavelength of 254 nm is utilized to promote the photolysis of ozone to generate excited-state oxygen atoms. The reaction process can be described as follows: generate It has an extremely high redox potential and undergoes a chain reaction with the ozone and ·OH free radicals continuously generated by the plasma module, which significantly enhances its ability to destroy microbial organic macromolecules.

[0009] Furthermore, the central controller in the intelligent environmental sensing and control system has an embedded microprocessor as its hardware core, integrating a multi-channel analog-to-digital converter and a digital communication interface. The ozone sensor employs an electrochemical principle, with a measurement range of 0–1 ppm and a resolution of 0.01 ppm. The ultraviolet intensity sensor is a silicon photodiode type, covering a spectral response of 200–400 nm, and is installed at 2–4 monitoring points at different distances from the ultraviolet module within the space. The central controller has a built-in sterilization strategy library, which stores preset control programs for different laboratory volumes, initial contamination levels, and target microbial types. Key parameters of the control programs include plasma pretreatment time, power ratio of the ultraviolet and plasma synergistic phases, ultraviolet module rotation speed, and ozone safety threshold. During system operation, the central controller collects data from each sensor in real time and dynamically adjusts the above parameters through a built-in fuzzy PID control algorithm to ensure that while achieving the preset logarithmic reduction value for sterilization, the peak ozone concentration in the space is controlled below 0.15 ppm.

[0010] Furthermore, the circulating air duct of the directional induced airflow system is designed in a laminar flow mode, with top air outlets being either slotted or perforated plates, and bottom return air outlets located at the four corners of the room. The fan uses a brushless DC fan, and its airflow can be adjusted within the range of 50–300 m³ / h according to the central controller's instructions. The HEPA filter has a filtration efficiency of no less than 99.97% for particles ≥0.3 μm in diameter. Downstream of the HEPA filter in the return air duct, an ozone decomposition catalytic unit is also installed. The catalyst is nano-manganese dioxide supported on a cordierite honeycomb ceramic carrier, with a specific surface area greater than 100 m² / g, and an ozone decomposition efficiency higher than 90% at room temperature. The operating logic of the airflow system is as follows: during the sterilization synergy stage, it operates at a lower airflow to promote thorough mixing and interaction between active particles and ultraviolet light in the space; in ozone decomposition mode, the fan switches to its highest setting, accelerating the flow of air containing residual ozone through the catalytic unit for rapid degradation.

[0011] On another front, a laboratory space sterilization method combining low-temperature plasma and ultraviolet light in rapid synergy is described, with the following specific steps: Step S110: The system is powered on and initialized. The central controller in the intelligent environmental perception and control system reads the baseline data of each sensor, including the initial ozone concentration, background ultraviolet intensity, temperature and humidity and particulate matter concentration. Based on the laboratory geometry and the initial pollution level assessment results, it matches and loads the corresponding collaborative sterilization control program from the sterilization strategy library. Step S120: Perform the plasma pretreatment stage. The central controller controls the ring array plasma generation module to operate at 20-40% of the rated power, and the pulse power supply operates at a specific frequency and duty cycle for 5-10 minutes to generate a cloud of active particles rich in ·OH and H2O2 in the top area of ​​the space, while initially reducing the amount of bacteria carried in the air. Step S130: Enter the UV-plasma synergistic sterilization stage. The central controller simultaneously starts the rotatable multi-directional UV radiation module and increases the power of the ring array plasma generator module to 60-85% of the rated value. The UV module rotates at a preset speed, the deep UV LED and UVC mercury lamp work in the selected mode, and the directional airflow system operates to match the air volume. This stage lasts for 6-10 minutes and uses the photo-plasma catalytic effect to achieve rapid inactivation of microorganisms in the space, including bacterial spores and viruses. Step S140: Activate the ozone decomposition and safety monitoring stage. The central controller shuts down the ultraviolet radiation module, reduces the power of the plasma generation module to 10-25% of the rated value, and adjusts the fan of the directional airflow system to the highest speed to force indoor air to circulate through the ozone decomposition catalytic unit. At the same time, the ozone concentration is continuously monitored until it is below the safety threshold of 0.05 ppm. Then the system enters standby mode.

[0012] Compared with the prior art, the present invention has the following beneficial effects: Through the systematic synergistic design of the ring plasma array and the central rotating ultraviolet module in terms of temporal overlap and spatial complementarity, and combined with the photocatalytic effect of 254 nm ultraviolet light on ozone, a synergistic enhancement effect of multiple highly active substances such as ·OH, O(¹D), and O3 was generated. Experimental verification showed that the inactivation rate of stubborn microorganisms such as Bacillus subtilis var. niger spores was increased by 3–5 times compared with single technology or simple superposition scheme.

[0013] The ring-shaped active particle generator and the centrally rotating wide-angle ultraviolet radiation source, with the assistance of directional induced airflow, form a three-dimensional sterilization network covering the three-dimensional space of the laboratory. This effectively eliminates traditional sterilization dead spots such as the back of the equipment and corners, achieving a spatial uniformity deviation of less than 15% under log6 level sterilization effect.

[0014] It integrates a closed-loop intelligent control mechanism based on multi-sensor feedback, which can monitor and dynamically adjust the ozone concentration in real time. After sterilization, it automatically starts a high-efficiency catalytic decomposition process to ensure that the peak ozone concentration is below 0.15 ppm throughout the entire operation cycle and drops to below 0.05 ppm within 30 minutes after sterilization, fully complying with indoor air quality safety standards such as GB / T 18202-2000.

[0015] Tests conducted on a standard 10 m³ laboratory space showed that the total time from system startup to completion of log6 sterilization could be controlled within 8–12 minutes, and the overall energy consumption was reduced by about 30% compared to traditional continuous high-power operation schemes, achieving a balance between speed, efficiency and low energy consumption.

[0016] The system is highly intelligent and adaptive. Its built-in sterilization strategy library can automatically optimize operating parameters according to different application scenarios and microbial loads. It supports remote monitoring, fault self-diagnosis and program upgrades, and is suitable for diverse clean environment needs from ordinary cell culture rooms to high-level biosafety laboratories. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall technical solution architecture of a laboratory space sterilization system that combines low-temperature plasma and ultraviolet rapid synergy, as proposed in this invention. Figure 2 This is a schematic diagram of the core principle framework of the photo-plasma catalytic synergistic effect in this invention; Figure 3 This is a logical flowchart of the collaborative sterilization method executed by the intelligent environmental perception and control system in this invention. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. Example

[0019] In a standard 10-cubic-meter cell culture laboratory, the space is rectangular and contains a biosafety cabinet, a CO2 incubator, a laminar flow hood, and several laboratory shelves. In this application scenario, the low-temperature plasma and ultraviolet rapid synergistic laboratory space sterilization system described in this invention begins to perform its intended functions. See also... Figure 1 The overall architecture of this system includes a ring-array plasma generation module, a rotatable multi-directional ultraviolet radiation module, an intelligent environmental sensing and control system, and a directional airflow system. These modules work collaboratively under the unified scheduling of a central controller to achieve efficient, rapid, and safe inactivation of microorganisms in the air and on object surfaces within the laboratory space.

[0020] The intelligent environmental sensing and control system first starts and performs an initial self-test. After the system powers on, the central controller reads and verifies the baseline data of each sensor. The ozone sensor measures the initial ozone concentration in the space in real time, and its measured value is usually close to zero; the ultraviolet intensity sensor detects the background ultraviolet radiation intensity to ensure there are no external interference light sources; the temperature and humidity sensor collects the current environmental temperature and humidity parameters, for example, a temperature of 22 degrees Celsius and a relative humidity of 45%; the particulate matter sensor monitors the concentration of suspended particulate matter in the air. The embedded microprocessor built into the central controller converts the above analog signals into digital signals through a multi-channel analog-to-digital converter and establishes a connection with each execution module through a digital communication interface. Based on the preset laboratory geometry parameters and the initial sensor data, the central controller performs a preliminary assessment of the initial pollution level of the space. The assessment logic is based on a correlation model between particulate matter concentration and temperature and humidity. If the particulate matter concentration is below 35 micrograms per cubic meter and the temperature and humidity are within a suitable range, it is determined to be a routine cleanroom maintenance scenario; if the particulate matter concentration is significantly increased or the temperature and humidity are abnormal, it may indicate a potential pollution risk. Based on the evaluation results, the central controller matches and loads the corresponding collaborative sterilization control program from the built-in sterilization strategy library. This control program is a predefined set of parameters, containing a sequence of operating parameters optimized for the current space volume, initial contamination level, and target microbial type. These parameters include, but are not limited to, plasma pretreatment duration, power ratio of the UV and plasma collaborative stages, UV module rotation speed, and safety thresholds for each stage.

[0021] After initialization, the system enters the plasma pretreatment stage defined in step S110. The central controller sends a command to the ring array plasma generation module, controlling it to start operating at 30% of its rated power. The ring array plasma generation module is installed along the edge of the laboratory ceiling, specifically with eight dielectric barrier discharge type cryogenic plasma generation units symmetrically arranged at the midpoints and corners of the four edges of the ceiling. The discharge electrode structure of each generation unit consists of a high-voltage electrode, a ground electrode, and a ceramic dielectric layer in between. The high-voltage electrode is connected to a pulse modulation power supply. In this stage, the central controller sets the output frequency of the pulse modulation power supply to 5 kHz and the duty cycle to 40%. This parameter configuration is designed to generate stable cryogenic plasma in the dielectric barrier discharge gap with a low instantaneous energy injection. During the discharge process, nitrogen, oxygen, and water molecules in the air dissociate and become excited under high-energy electron collisions, generating highly reactive particles including hydroxyl radicals, hydrogen peroxide, superoxide anions, and a small amount of ozone. These active particles are released from the discharge region of each generating unit. Due to the ring-shaped symmetrical distribution of the units, they overlap at the top of the space and slowly diffuse downwards, gradually forming an initial cloud rich in active particles. This pretreatment stage lasts for 8 minutes. During this period, short-lived active species such as generated hydroxyl radicals can rapidly react with airborne bacteria and some microorganisms attached to aerosol particles, initially reducing the airborne bacterial load. At the same time, water molecules in the active particle cloud are continuously activated, storing reaction precursors for subsequent synergistic stages. The directional induced airflow system operates at its lowest setting during this stage, with the fan speed set to 50 cubic meters per hour. Its function is to gently agitate the air, promoting the initial mixing of active particles, but avoiding excessively strong airflow that would prematurely disperse or dilute the active particles.

[0022] After the pretreatment stage, the system seamlessly switches to the UV-plasma synergistic sterilization stage defined in step S120. This is the core sterilization stage of the invention, designed to generate a "photo-plasma catalysis" enhancement effect. See also Figure 2This effect describes the interaction principle between ultraviolet light and plasma active substances under temporal overlap and spatial complementarity. The central controller synchronously executes the following commands: First, it increases the operating power of the ring-array plasma generator module to 75% of its rated value. The parameters of the pulse modulation power supply are adjusted accordingly, with the frequency increased to 12 kHz and the duty cycle adjusted to 60% to increase the yield of active particles, especially ozone and long-lived reactive oxygen species. Second, the central controller activates the rotatable multi-directional ultraviolet radiation module. This module is suspended above the central area of ​​the laboratory via a lifting and rotating mechanism. The central controller controls the stepper motor drive mechanism, causing the ultraviolet radiation module to begin rotating 360 degrees around its vertical axis at a preset speed of 3 revolutions per minute. Simultaneously, the module height decreases by 0.8 meters from its initial position to optimize its radiation coverage angle. The ultraviolet radiation module contains two light sources: one is a deep ultraviolet LED array, with the emission wavelength of each LED strictly controlled at 275 nanometers and a light power of 55 milliwatts; the other is a conventional UVC mercury lamp with a dominant emission wavelength of 254 nanometers. In this embodiment, the central controller selects an "alternating illumination" working mode. The specific control logic is as follows: the deep ultraviolet LED array is illuminated at full power for 60 seconds, during which the UVC mercury lamp is turned off; after 60 seconds, the deep ultraviolet LED array is turned off, and the UVC mercury lamp is illuminated at full power for another 60 seconds, and this cycle repeats. This mode helps balance the heat generation of different light sources, optimizes internal thermal management of the module, and thus extends the lifespan of the light source devices. The directional airflow system adjusts its airflow to 150 cubic meters per hour during this stage. The top air outlet adopts a slotted design, forming laminar airflow, with the airflow flowing slowly from top to bottom; the bottom return air outlets are located at the four corners of the room, drawing back the lower-level air. This airflow pattern forms a gentle but directional circulation within the space. Its core function is to guide the high concentration of active particles generated by the top plasma module to diffuse into the lower space, while simultaneously continuously refreshing the air in the space "sweeped" by the ultraviolet light emitted by the rotating ultraviolet module to the light radiation area, ensuring that the active particles and ultraviolet light are fully mixed and contacted in three-dimensional space.

[0023] During the eight-minute synergistic phase, complex physicochemical reactions occurred between ultraviolet light and plasma-active substances, forming the microscopic basis of the "photo-plasma catalysis" effect. On one hand, ozone molecules continuously generated by the plasma diffused throughout space. On the other hand, the 254-nanometer wavelength ultraviolet light emitted by the rotating UVC mercury lamp exhibited characteristic absorption of ozone molecules. After absorbing photons of this wavelength, ozone molecules underwent photolysis, following a specific photochemical pathway to generate oxygen molecules and an excited-state oxygen atom. This excited-state oxygen atom possesses extremely high redox potential and reactivity. These newly generated excited-state oxygen atoms, upon encountering other reactive species such as hydroxyl radicals and hydrogen peroxide generated by the plasma, triggered a series of chain reactions, producing more reactive intermediates, thereby significantly enhancing the oxidative damage to key biomolecules such as microbial cell walls, cell membranes, proteins, and nucleic acids. Simultaneously, the 275-nanometer ultraviolet light emitted by the deep ultraviolet LED directly destroyed the deoxyribonucleic acid structure of microorganisms, forming pyrimidine dimers and leading to their inactivation. The rotating ultraviolet module ensures that ultraviolet light at wavelengths of 254 nm and 275 nm covers the entire space without blind spots, including the back and corners of the device, while the ring-shaped top-mounted plasma array provides a continuous and uniform background field of active chemicals. These two elements overlap in time and complement each other spatially, working together to achieve rapid and efficient inactivation of stubborn microorganisms such as Bacillus subtilis var. niger spores and bacteriophages. The central controller monitors the ultraviolet radiation dose at multiple locations within the space in real time using an ultraviolet intensity sensor and monitors ozone concentration changes using an ozone sensor. It dynamically fine-tunes the plasma power and fan airflow using a built-in fuzzy proportional-integral-derivative control algorithm, ensuring that the peak ozone concentration is precisely controlled below 0.12 ppm, guaranteeing both sterilization efficacy and adhering to safety limits.

[0024] After the co-sterilization stage reaches the preset time, the system automatically enters the ozone decomposition and safety monitoring stage defined in step S130. The central controller first sends a command to shut down all light sources of the rotatable multi-directional ultraviolet radiation module and stop its rotation. Subsequently, the power of the ring array plasma generator module is drastically reduced to 15% of its rated value. At this time, the plasma discharge is mainly used to maintain the generation of a small number of active particles to assist the subsequent catalytic decomposition process, rather than the primary sterilization. The most critical operation is that the central controller adjusts the brushless DC fan of the directional airflow system to its highest speed, achieving an airflow of 300 cubic meters per hour. The powerful airflow rapidly draws the indoor air containing residual ozone into the bottom return air vent. In the return air duct, the air first passes through a high-efficiency air filter, which has a filtration efficiency of 99.97% for particles with a diameter of 0.3 micrometers or larger, and can capture particles that may carry microorganisms. Subsequently, the air flows through the ozone decomposition catalytic unit located downstream of the high-efficiency air filter. The core of this unit is a cordierite honeycomb ceramic catalyst carrier loaded with nano-manganese dioxide, boasting a specific surface area of ​​up to 120 square meters per gram and an ozone decomposition efficiency exceeding 92% at room temperature. When ozone-containing air flows at high speed through the micropores of the catalyst, ozone molecules are catalytically decomposed into oxygen at the active sites of the nano-manganese dioxide. Simultaneously, the central controller continuously collects data from the ozone sensor at a high frequency. The monitoring logic reads the concentration value every 5 seconds and compares it with the safe threshold of 0.05 ppm. Once the ozone concentration is detected to be below 0.05 ppm for 30 seconds, the central controller determines that the ambient environment is safe, then switches all system modules to standby or low-power mode and sends a "sterilization complete, environment safe" status report to the upper-level monitoring system via digital communication interface. During the entire ozone decomposition phase, the system takes approximately 18 minutes to reduce the ozone concentration from approximately 0.1 ppm at the end of the synergistic phase to below 0.05 ppm, fully meeting the ozone limit requirements of relevant indoor air quality standards. Example

[0025] Within a 25-cubic-meter preparation room of a biosafety level 2 laboratory with an irregular polygonal structure, centrifuges, shakers, refrigerators, and numerous boxes of experimental equipment awaiting sterilization are stored. The spatial layout is complex, with numerous obstructions and blind spots. This system is designed for adaptive sterilization operations in this enlarged and structurally complex space.

[0026] After the system is powered on and initialized, the central controller in the intelligent environmental perception and control system executes step S110. In addition to reading baseline data such as ozone, UV intensity, temperature, humidity, and particulate matter, the system also identifies an increased space volume and the presence of obstacles such as pillars based on pre-stored laboratory 3D model data. The central controller assesses the scenario as a medium contamination load based on the high initial concentration detected by the particulate matter sensor. Accordingly, it retrieves a control program optimized for the "medium to large volume, complex structure, medium contamination" scenario from the sterilization strategy library. This program is pre-programmed with a longer pre-processing time, higher collaborative stage power, and a more flexible UV module scanning strategy.

[0027] The process proceeds to step S120, the plasma pretreatment stage. The central controller controls the ring array plasma generator module to operate at 35% of its rated power. For larger spaces, the pulse modulation power supply parameters are set to a frequency of 8 kHz and a duty cycle of 50% to ensure both high reactive particle yield and diffusion to more distant corners. The pretreatment time is extended to 10 minutes. During this period, the directional induced airflow system operates at a flow rate of 80 cubic meters per hour, designed to create a wider airflow disturbance, helping the reactive particle cloud penetrate into the equipment gaps and behind the packaging box.

[0028] The ultraviolet-plasma synergistic sterilization stage, step S130, is then executed. The central controller increases the plasma module power to 80% of its rated value, adjusts the pulse parameters to a frequency of 15 kHz and a duty cycle of 70%. The lifting and rotating mechanism of the rotatable multi-directional ultraviolet radiation module executes a "variable height scanning" mode according to a preset program: first, it rotates at a high position for 3 minutes at a speed of 2 revolutions per minute for wide coverage; then it descends to a middle height and rotates at a speed of 4 revolutions per minute for 3 minutes to enhance radiation to the middle and lower spaces; finally, it descends again to a lower height and rotates at a speed of 1.5 revolutions per minute for 4 minutes to focus on irradiating the ground and the area under the equipment. The ultraviolet light source adopts a "synchronous full power" mode, that is, the deep ultraviolet LED array and the UVC mercury lamp are lit at full power simultaneously to provide the strongest instantaneous ultraviolet radiation dose in complex spaces. The directional airflow system dynamically adjusts its airflow. When the UV module is at a mid-to-high level, the airflow is 200 cubic meters per hour; when the UV module descends to a lower level, the airflow decreases to 100 cubic meters per hour to reduce ground dust. The entire coordination phase lasts 10 minutes. The central controller uses UV intensity sensors deployed in the four quadrants of the room and next to the central pillar to provide real-time feedback on the UV radiation dose in each area and dynamically fine-tunes the rotation speed and dwell time to ensure spatial uniformity. The ozone sensor network monitors the ozone concentration in each area in real time. The central controller uses a fuzzy proportional-integral-derivative control algorithm to strictly control the overall ozone peak concentration in the space below 0.14 ppm.

[0029] After the collaborative phase, the system enters step S140, the ozone decomposition and safety monitoring phase. Due to the increased space volume, the central controller, after shutting down the ultraviolet module and reducing plasma power, extends the time for the directional airflow system's fans to run at maximum speed to 25 minutes. The powerful airflow ensures that ozone-containing air from all areas is effectively drawn in and flows through the ozone decomposition catalytic unit in the return air duct. The central controller continuously monitors the ozone concentration until the readings at all monitoring points are consistently below 0.05 ppm for 1 minute, at which point safety is confirmed and the system enters standby mode. In this scenario, the total system operation time is approximately 50 minutes, including 20 minutes of active sterilization and 30 minutes of ozone removal, successfully achieving log6-level uniform sterilization of the complex, large space, with ozone safety and controllability throughout the process.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A laboratory space sterilization system that combines low-temperature plasma and rapid ultraviolet light, characterized in that, The system includes the following components: A ring-array plasma generation module is used to install multiple dielectric barrier discharge type low-temperature plasma generation units along the edge of the laboratory ceiling or the upper part of the four walls. The units are arranged in a ring to form a highly active particle cloud at the top of the space. A rotatable multi-directional ultraviolet radiation module, mounted on a lifting and rotating mechanism above the central area of ​​the laboratory, includes at least one set of deep ultraviolet LED arrays and one set of UVC mercury lamps. The ultraviolet radiation module can rotate 360° around its vertical axis and its height can be adjusted vertically. An intelligent environmental sensing and control system includes an ozone sensor, an ultraviolet intensity sensor, a temperature and humidity sensor, a particulate matter sensor, and a central controller. The central controller dynamically adjusts plasma power, ultraviolet radiation intensity, operating sequence, and rotation speed based on sensor data. A directional induced airflow system consists of a circulating air duct composed of top air supply and bottom return air, and incorporates a built-in HEP ​​(High-Efficiency Particulate Air). A filter guides the plasma active particles and ultraviolet light to cover the entire space and accelerate ozone decomposition. In the collaborative working mode, executed by the central controller, after system startup, low-power plasma pretreatment is first performed for 5–10 minutes to activate moisture in the air and generate ·OH free radicals. Subsequently, the ultraviolet module starts and rotates, while the plasma module is upgraded to medium-high power. The two overlap in time and complement each other in space, forming a "photo-plasma catalysis" effect. After sterilization, the system automatically switches to "ozone decomposition mode," turns off the ultraviolet light, and maintains low-power plasma to work with the catalyst to degrade residual ozone to <0.05 ppm.

2. The laboratory space sterilization system of low-temperature plasma and ultraviolet rapid synergy according to claim 1, characterized in that, The dielectric barrier discharge type low-temperature plasma generating unit in the ring array plasma generating module has a discharge electrode structure consisting of a high-voltage electrode, a ground electrode, and a dielectric layer located therebetween. The high-voltage electrode is connected to a pulse modulation power supply, the output frequency of which is 1–20 kHz and the duty cycle is continuously adjustable in the range of 10% to 90%.

3. The laboratory space sterilization system of low-temperature plasma and ultraviolet rapid synergy according to claim 1, characterized in that, The lifting and rotating mechanism of the rotatable multi-directional ultraviolet radiation module is driven by a stepper motor, and its rotation speed is infinitely adjustable within the range of 0.5–12 rpm, with a lifting stroke of 0.5–2.0 meters; the emission wavelength of the deep ultraviolet LED array is controlled within the range of 265–280 nm, and the main emission wavelength of the UVC mercury lamp is 254 nm; the central controller is configured to control the deep ultraviolet LED array and the UVC mercury lamp to operate in alternating lighting or synchronous full-power mode, and when the alternating lighting mode is used, its switching cycle is 30–120 seconds.

4. The laboratory space sterilization system of rapid synergy between low-temperature plasma and ultraviolet light according to claim 1, characterized in that, The central controller in the intelligent environmental perception and control system has an embedded microprocessor as its hardware core, integrating a multi-channel analog-to-digital converter and a digital communication interface. The central controller has a built-in sterilization strategy library, which stores preset control programs for different laboratory volumes, initial contamination levels, and target microbial types. When the system is running, the central controller collects data from various sensors in real time and dynamically adjusts the control program parameters through a built-in fuzzy PID control algorithm to ensure that while achieving the preset logarithmic reduction value for sterilization, the peak ozone concentration in the space is controlled below 0.15 ppm.

5. The laboratory space sterilization system of low-temperature plasma and ultraviolet rapid synergy according to claim 1, characterized in that, The circulating air duct of the directional induced airflow system is designed in a laminar flow mode. The top air outlet is a slotted type or a perforated plate type, and the bottom return air outlet is located in the four corners of the room. The fan is a brushless DC fan, and its air volume can be adjusted within the range of 50–300 m³ / h according to the instructions of the central controller. In the return air duct, downstream of the HEPA filter, an ozone decomposition catalytic unit is also set. The catalyst is nano-manganese dioxide supported on a cordierite honeycomb ceramic carrier, and its ozone decomposition efficiency is higher than 90% at room temperature.

6. A laboratory space sterilization method using rapid synergy of low-temperature plasma and ultraviolet light, characterized in that, The specific steps of this method are as follows: Step S110: The system is powered on and initialized. The central controller in the intelligent environmental perception and control system reads the baseline data of each sensor, including the initial ozone concentration, background ultraviolet intensity, temperature and humidity and particulate matter concentration. Based on the laboratory geometry and the initial pollution level assessment results, it matches and loads the corresponding collaborative sterilization control program from the sterilization strategy library. Step S120: Perform the plasma pretreatment stage. The central controller controls the ring array plasma generation module to operate at 20-40% of the rated power, and the pulse power supply operates at a specific frequency and duty cycle for 5-10 minutes to generate a cloud of active particles rich in ·OH and H2O2 in the top area of ​​the space, while initially reducing the amount of bacteria carried in the air. Step S130: Enter the UV-plasma synergistic sterilization stage. The central controller simultaneously starts the rotatable multi-directional UV radiation module and increases the power of the ring array plasma generator module to 60-85% of the rated value. The UV module rotates at a preset speed, the deep UV LED and UVC mercury lamp work in the selected mode, and the directional airflow system operates to match the air volume. This stage lasts for 6-10 minutes and uses the photo-plasma catalytic effect to achieve rapid inactivation of microorganisms in the space, including bacterial spores and viruses. Step S140: Activate the ozone decomposition and safety monitoring stage. The central controller shuts down the ultraviolet radiation module, reduces the power of the plasma generation module to 10-25% of the rated value, and adjusts the fan of the directional airflow system to the highest speed to force indoor air to circulate through the ozone decomposition catalytic unit. At the same time, the ozone concentration is continuously monitored until it is below the safety threshold of 0.05 ppm. Then the system enters standby mode.

7. The laboratory space sterilization method of rapid synergy between low-temperature plasma and ultraviolet light according to claim 6, characterized in that, In step S130, the photo-plasma catalytic effect includes: utilizing the characteristic absorption of ozone molecules by 254 nm wavelength ultraviolet light emitted by a UVC mercury lamp to promote the photolysis of ozone to generate excited-state oxygen atoms. The reaction process is as follows: generated It undergoes a chain reaction with the ·OH free radicals generated by the plasma module, enhancing its ability to destroy microbial organic macromolecules.

8. The laboratory space sterilization method of rapid synergy between low-temperature plasma and ultraviolet light according to claim 6, characterized in that, In step S130, the central controller uses a built-in fuzzy PID control algorithm to dynamically fine-tune the plasma power, the rotation speed of the ultraviolet module, and the airflow of the directional induced airflow system based on real-time collected data from the ozone sensor and the ultraviolet intensity sensor, ensuring that the peak ozone concentration is controlled below a preset safety threshold.

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