Multi-disinfection-and-killing-factor cooperative regulation and control method for public space air disinfection

Abstract

The invention discloses a multi-disinfection-factor coordinated regulation method for public space air disinfection, and belongs to the technical field of public space air disinfection, and the method comprises the following steps: 1, analyzing the condition that public space pathogens infect a human body; step 2, obtaining controllable disinfection and killing parameters; 3, introducing an intelligent feedback control factor; step 4, introducing the disinfection effect of the plasma as a feedback factor; 5, introducing the disinfection effect of ultraviolet rays as a feedback factor; 6, dynamically adjusting the plasma and ultraviolet output level in cooperation with a control factor; and step 7, establishing flow control and plasma and ultraviolet disinfection factor comprehensive feedback control. According to the invention, the disinfection effect generated by the plasma and ultraviolet technology is taken as a feedback factor to be included in the calculation method, so that low-cost, broad-spectrum, stable and pollution-free disinfection is realized, and the human body infection rate in the public space is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of public space air disinfection, and in particular relates to a method for coordinated regulation of multiple disinfection factors for public space air disinfection. Background Art

[0002] Humans often gather in public spaces for production and life activities. As a substance that humans rely on for survival, the air in public spaces usually carries various pathogens such as bacteria, viruses, fungi, allergenic pollen, mold spores, and parasite eggs. These pathogens usually use solid or liquid particles as carriers, attach to them and disperse in the gas to form a relatively stable suspension system with a kinetic diameter of 1 nm~100 μm, forming an aerosol and spreading. Aerosols are contagious and allergenic, which not only endangers human health, but also causes air pollution, food decay, water quality deterioration, etc., and should be given enough attention.

[0003] In recent years, the spread of bioaerosols containing pathogenic microorganisms has been a thorny issue causing public space safety incidents. The droplets exhaled by a person coughing or sneezing are a mixture of water and solid particles, namely bioaerosols. The particle size of aerosols is an important factor affecting whether they can enter the human respiratory tract and deposit inside the body to produce toxic effects. Since droplets usually contain solutes, droplet nuclei will form after evaporation. Generally speaking, the particle size of droplet nuclei is usually less than 5 μm. Studies have shown that the particle size of droplet nuclei formed by patients' natural coughing (not artificially induced) is generally 2.1~3.3 μm. Inhalable particles with a particle size of less than 10 μm can pass through the throat and enter the trachea or bronchi, especially fine particles with a particle size of less than 2.5 μm can be deposited in the alveoli, which is extremely harmful to human health. In order to protect the lives, health and safety of the people, it is necessary to use artificial intervention methods for disinfection.

[0004] According to the different disinfection mechanisms, they can be divided into physical, chemical and biological methods. Physical disinfection methods mainly include natural ventilation, electrostatic adsorption, high-voltage pulse electric field, photocatalytic disinfection, low-temperature plasma disinfection and ultraviolet disinfection; chemical disinfection methods include fumigation, aerosol and ozone; biological disinfection methods are divided into animal and plant disinfection and lysozyme disinfection.

[0005] In the physical disinfection method, the effect of ventilation method depends on the quality of external atmospheric air, and the effect is unstable and low. In the filtration sterilization method, the filter needs to be replaced frequently, which is costly and does not really kill microorganisms. The electrostatic adsorption method has a large environmental noise, and the sterilization effect is unstable, which will decrease with the extension of use time. In addition, the disinfection effect of filtration sterilization and electrostatic adsorption is seriously dependent on the cleanliness of the air. When there is a lot of dust in the environment, the disinfection effect is seriously low. The high-voltage pulse electric field method takes a short time to disinfect, is simple to operate and has low energy consumption, but it will produce ozone byproducts. The photocatalytic disinfection method mainly uses semiconductor catalysts such as titanium dioxide and zinc oxide. After being irradiated by sunlight and ultraviolet light, photoelectrons and holes are generated on the crystal surface, which then react with water molecules and oxygen adsorbed on its surface to generate strong oxidizing active groups such as hydroxyl free radicals and reactive oxygen. While sterilizing, it can degrade other harmful substances in the air. However, this method is limited by the catalyst preparation process and the catalyst is easily poisoned and inactivated by the environment, resulting in unstable disinfection effect. Low-temperature plasma disinfection has a fast disinfection effect and is clean without residue, but the disinfection effect is limited by the distribution and content of active particles in the plasma. Ultraviolet disinfection uses ultraviolet rays with a characteristic absorption peak in the 254 nm band to directly destroy the deoxyribonucleic acid in the cells of pathogenic microorganisms, causing the microorganisms to lose their ability to replicate or die directly. It is easy to operate, simple equipment, rapid sterilization, and no secondary pollution, but it has poor penetration ability, dead corners for disinfection, short sterilization effect, and ultraviolet irradiation is harmful to the human body. It is necessary to strictly control the dosage and radiation distance to avoid harm to humans and animals while producing the effect.

[0006] In the chemical disinfection method, the fumigation method uses the oxidizing and acidic effects of chemicals such as peracetic acid, chlorine dioxide, and vinegar to destroy the cell membrane structure of bacteria and then destroy important substances inside. Although this method is simple and easy to use, there will be residual agents and corrosive effects on indoor items. The aerosol method is an improvement on the fumigation method. It uses atomization equipment to increase the utilization rate of drugs, but it still produces secondary pollution such as corrosion and residues, and operators need strict protective equipment. The ozone method uses the strong oxidizing property of ozone. Ozone can decompose to generate oxygen molecules and active oxygen atoms at room temperature. Active oxygen atoms are the main substances for its disinfection effect. Adding a catalyst can accelerate the decomposition reaction and increase the generation rate of active particles such as oxygen atoms. When the concentration of ozone in the air is very low, it shows a bactericidal effect. It has the advantages of fast disinfection, no residue, broad-spectrum bactericidal, and no dead corners. However, ozone is harmful to human health and corrosive to building materials, so the ozone content in the air needs to be strictly controlled.

[0007] Among the biological disinfection methods, the animal and plant disinfection method mainly utilizes the alkaloids, organic acids, volatile oils, and induced antimicrobial peptides contained in them, which have antibacterial and bactericidal substances. Compared with the chemical agent method, it has low toxicity and mild performance, but its bactericidal types are limited, it still produces secondary particulate pollution, and its application range is narrow. The lysozyme disinfection method uses lysozyme with in vitro bactericidal activity in organisms to act on the cell walls of microorganisms, causing them to dissolve, penetrate, and then die. When it is used for air disinfection, it is often used in combination with other methods. This method has bactericidal specificity, is reusable, has low loss, and has no secondary pollution. Its disadvantages are that it is greatly affected by external air conditions (especially temperature), has a slow bactericidal rate, and requires the combined application of multiple enzymes.

[0008] In general, a single disinfection factor has unique limitations, which may be limited by the disinfection principle or controlled by external conditions, and is not enough to effectively disinfect pathogens in bioaerosols. Therefore, a combination of multiple disinfection factors is needed to eliminate pathogens to achieve air purification and disinfection, and reduce the risk of infection in crowded areas. However, the coordinated control of multiple disinfection factors is an important challenge. How to activate the ineffectiveness of disinfection factors caused by environmental effects, how to achieve broad-spectrum, large-area, and no-dead-angle disinfection, and how to maintain a balance between effective disinfection and protection of the human body and the environment all require solutions. Summary of the invention

[0009] Combined with the above background technology, pathogens in the air are a major hidden danger that affects human health. In order to ensure the safety of the public space environment, the air in the public space needs to be fully disinfected to eliminate pathogens and control the pathogen content to meet the requirements of human health levels. Traditional physical and chemical disinfection methods require the replacement of consumables and produce a large amount of waste that pollutes the environment. These wastes containing pathogens may also pose a risk of secondary transmission. Biological disinfection methods generally do not have broad-spectrum bactericidal capabilities and are slow, and their scope of application is also narrow. In order to overcome the above-mentioned defects, it is necessary to combine air flow control, plasma and ultraviolet technology. The present invention takes the disinfection effect produced by plasma and ultraviolet technology as a feedback factor into the calculation method to achieve low-cost, broad-spectrum, stable, and pollution-free disinfection, thereby reducing the infection rate of humans in public spaces.

[0010] At present, there is no feedback control of air flow speed in public spaces. Relying solely on natural air convection, fixed speed or simply variable speed forced air convection cannot or is difficult to achieve a stable disinfection effect, and consumes excessive energy. In order to solve the problem of air flow speed feedback control and achieve large-area, no-dead-angle disinfection, it is necessary to introduce air flow control.

[0011] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0012] A method for coordinated regulation of multiple disinfection factors for air disinfection in public spaces, comprising the following steps: Step 1: Analyze the infection of human body by pathogens in public spaces; Step 2: Obtain controllable disinfection parameters; Step 3: Introduce intelligent feedback control factors; Step 4: Introduce the disinfecting effect of plasma as a feedback factor; Step 5: Introduce the disinfecting effect of ultraviolet light as a feedback factor; Step 6: Dynamically adjust the plasma and ultraviolet output levels in conjunction with the control factors; Step 7: Establish comprehensive feedback control including flow control, plasma and ultraviolet disinfection factors.

[0013] Beneficial effects: The present invention proposes a method for coordinated regulation of multiple disinfection factors for air disinfection in public spaces. The method covers multiple disinfection factors such as flow control, plasma, and ultraviolet rays, and solves the problem of disinfection failure by regulating and activating different disinfection factors, thereby achieving effective disinfection of bioaerosols containing pathogenic microorganisms and avoiding the occurrence of public biosafety incidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of a method for coordinated regulation of multiple disinfection factors for air disinfection in public spaces according to the present invention; Figure 2 To determine the effect of the disinfecting factor on the pathogen content. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example: A method for coordinated regulation of multiple disinfection factors for air disinfection in public spaces, comprising the following steps: Step 1: Analyze the infection of pathogens in public spaces When humans breathe air containing pathogens, the probability of infection caused by pathogens in different people is different due to different immune abilities. Therefore, the infection probability can be expressed as: (1) In the formula, V is the amount of gas exhaled per unit time; S is the replacement rate of air inside the public space; C0 is the content of pathogens in the air; t is the exposure time; A is the human immunity coefficient.

[0017] Considering the exchange of pathogens caused by contact between people in public spaces, some pathogens will be brought out when exhaling, and formula (1) can be further modified as follows: (2) Where α is the transmission coefficient of pathogen carriers; β is the pathogen removal coefficient in the body.

[0018] Step 2: Obtain controllable disinfection parameters After shifting the terms in equation (2), we can take the logarithm of both sides and transform it into: (3) Since there is a certain relationship between the replacement rate S of the air inside the public space, the content C of pathogens in the air and the disinfection measures, which are controllable disinfection factors, formula (3) can be further rewritten as: (4) Step 3: Introducing intelligent feedback control factors Intelligent feedback is used to control the air replacement rate in public spaces. The air replacement rate S changes from a normal constant to a function of time and control factors. When people are exposed to public spaces, various disinfection measures are also carried out simultaneously, that is, it is considered that the exposure time coincides with the disinfection time, then: (5) Where S0 is the internal air replacement rate of conventional public spaces; k is the control factor.

[0019] In formula (5), the value of the control factor k is related to the content of pathogens in the air. In order to match the control factor with the pathogen content corresponding to the human health level, the control factor as a parameter needs to be given in combination with a specific control algorithm to maximize cost and efficiency. When the pathogen content in the air is high, an exponential control algorithm is used to quickly reduce the pathogen content; when the pathogen content in the air is medium, a proportional, differential and integral control algorithm is used to dynamically reduce the pathogen content; when the pathogen content in the air is low, a logarithmic control algorithm is used to make the pathogen content fluctuate within the range allowed by human health.

[0020] The infection probability with the introduction of intelligent feedback control can be further expressed as: (6) Intelligent feedback control takes into account the role of air replacement rate in public spaces in reducing the probability of infection. In order to better regulate the content of pathogens in the air, the control algorithm needs to be combined with plasma and ultraviolet technology.

[0021] Step 4: Introducing the disinfection effect of plasma as a feedback factor The active particles in the plasma act on pathogens to disinfect them. Regulating the distribution and content of active particles is the key to achieving effective disinfecting. Under the action of plasma, the content of pathogens meets the following requirements: (7) Where γ1 is the conversion efficiency of active particles in plasma; U plasma is the output voltage of the plasma excitation source; I plasma Output current for the plasma excitation source.

[0022] In order to improve the conversion efficiency of plasma active particles, specific proportions of oxygen, water vapor, etc. can be added to the plasma reaction area to achieve regulation of the types of active particles. The above-mentioned air flow control can adjust the distribution of active particle content, and the active particles can be forcibly transported to every corner of the public space to achieve large-area, no-dead-angle disinfection, thereby comprehensively improving the disinfection effect.

[0023] Step 5: Introduce the UV disinfecting effect as a feedback factor Ultraviolet rays are sensitive to viruses and bacteria and have a fast action speed. Under the action of ultraviolet rays, the content of pathogens meets the following requirements: (8) Where γ2 is the product of the attenuation coefficient of pathogenic microorganisms to ultraviolet rays and the photoelectric conversion efficiency; U UV is the voltage to drive the UV lamp; I UV is the current driving the UV lamp; S UV is the ultraviolet irradiation area.

[0024] The attenuation coefficient of ultraviolet rays for pathogenic microorganisms is related to the distance. The disinfection effect drops sharply after exceeding a certain distance. The above-mentioned air flow control can bring pathogenic microorganisms into the effective disinfection range of ultraviolet rays, thereby effectively increasing the attenuation coefficient and improving the disinfection effect.

[0025] Step 6: Dynamically adjust plasma and UV output levels with control factors In order to cooperate with the control factor adjustment, the plasma excitation voltage, current and time as well as the ultraviolet drive voltage, current and time can be automatically controlled in a programmed manner or manually controlled to achieve exponential, proportional, differential plus integral and logarithmic outputs.

[0026] Step 7: Establish comprehensive feedback control including flow control, plasma and ultraviolet disinfection factors Substituting equations (7) and (8) into equation (9), we can obtain the infection probability with the disinfection effect produced by plasma and ultraviolet technology as the feedback factor.

[0027] (9) In the formula, l1 is the plasma disinfecting coefficient; l2 is the ultraviolet disinfecting coefficient.

[0028] Formula (9) is used to establish the numerical connection between infection probability and flow control, plasma and ultraviolet disinfection factors, thereby realizing feedback control of disinfection effect.

[0029] According to the method in the above embodiment, experiments were conducted to verify the disinfection effects of plasma, ultraviolet light, and combined plasma and ultraviolet light under intelligent feedback flow control. Figure 2 As shown in the figure, the pathogen content in the air dropped rapidly under the action of the disinfection factor, dropping by 2 orders of magnitude in just 15 minutes, and the combined plasma and ultraviolet mode could drop by up to 4 orders of magnitude. The above results show that the combined disinfection factor can effectively protect the safety of the human body in public spaces and avoid infection.

[0030] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for coordinated regulation of multiple disinfection factors for air disinfection in public spaces, characterized in that: The steps include: Step 1: Analyze the infection of human body by pathogens in public spaces; Step 2: Obtain controllable disinfection parameters; Step 3: Introduce intelligent feedback control factors; Step 4: Introduce the disinfecting effect of plasma as a feedback factor; Step 5: Introduce the disinfecting effect of ultraviolet light as a feedback factor; Step 6: Dynamically adjust the plasma and ultraviolet output levels in conjunction with the control factors; Step 7: Establish comprehensive feedback control including flow control, plasma and ultraviolet disinfection factors.

2. A method for coordinated regulation of multiple disinfection factors for air disinfection in public spaces according to claim 1, characterized in that: In step 1, when humans breathe air containing pathogens, the probability of infection is expressed as: (1) In the formula, V is the amount of gas exhaled per unit time; S is the replacement rate of air inside the public space; C0 is the content of pathogens in the air; t is the exposure time; A is the human immunity coefficient; Considering the exchange of pathogens caused by contact between people in public spaces, some pathogens will be brought out when exhaling, and formula (1) can be modified to: (2) Where α is the transmission coefficient of pathogen carriers; β is the pathogen removal coefficient in the body.

3. The method for coordinated regulation of multiple disinfection factors for public space air disinfection according to claim 1, characterized in that: In step 2, after shifting the terms in equation (2), take the logarithm of both sides and transform equation (2) into (3) Since there is a relationship between the replacement rate S of the air inside the public space, the content C of pathogens in the air and the disinfection measures, formula (3) is rewritten as: (4)。 4. The method for coordinated regulation of multiple disinfection factors for public space air disinfection according to claim 1, characterized in that: In step 3, intelligent feedback is used to control the replacement rate of the air inside the public space. The air replacement rate S changes from a normal constant to a function of time and control factors. It is assumed that the exposure time coincides with the disinfection time, then: (5) In the formula, S0 is the air replacement rate inside the conventional public space; k is the control factor; In formula (5), the value of the control factor k is related to the content of pathogens in the air. When the content of pathogens in the air is high, an exponential control algorithm is used; when the content of pathogens in the air is medium, a proportional, differential and integral control algorithm is used; when the content of pathogens in the air is low, a logarithmic control algorithm is used. The infection probability of introducing intelligent feedback control is expressed as follows: (6)。 5. The method for coordinated regulation of multiple disinfection factors for public space air disinfection according to claim 1, characterized in that: In step 4, the active particles in the plasma act on the pathogens to disinfect them. Under the action of the plasma, the content of the pathogens meets the following conditions: (7) Where γ1 is the conversion efficiency of active particles in plasma; U plasma is the output voltage of the plasma excitation source; I plasma Output current for the plasma excitation source.

6. The method for coordinated regulation of multiple disinfection factors for public space air disinfection according to claim 1, characterized in that: In step 5, the pathogenic microorganisms are subjected to ultraviolet light, and the content of the pathogens meets the following requirements: (8) Where γ2 is the product of the attenuation coefficient of pathogenic microorganisms to ultraviolet rays and the photoelectric conversion efficiency; U UV is the voltage to drive the UV lamp; I UV is the current driving the UV lamp; S UV is the ultraviolet irradiation area.

7. The method for coordinated regulation of multiple disinfection factors for public space air disinfection according to claim 1, characterized in that: In step 6, the plasma excitation voltage, current and time and the ultraviolet driving voltage, current and time are automatically controlled or manually controlled in a programmed manner.

8. The method for coordinated regulation of multiple disinfection factors for public space air disinfection according to claim 1, characterized in that: In step 7, substitute equations (7) and (8) into equation (9) to obtain the infection probability with the disinfection effect produced by plasma and ultraviolet technology as the feedback factor; (9) In the formula, l1 is the plasma disinfecting coefficient; l2 is the ultraviolet disinfecting coefficient.

Images