Method for finely calculating disinfection rate of ultraviolet disinfection device

Abstract

The invention discloses a method for finely calculating the disinfection rate of an ultraviolet disinfection device, and belongs to the technical field of ultraviolet disinfection. According to the method, the ultraviolet irradiation intensity of the disinfection space is finely calculated through the steps of gridding the disinfection space, accurately calculating the position angle coefficient of each grid, calculating the output power of a disinfection lamp tube and the like. Through an actual test mode, the microbial standard death constants of the air conditioning systems of different cities and different building types are iterated, and finally the current situation that disinfection modules of existing microbial disinfection products are simply stacked is changed; the microbe disinfection rate of the disinfection product and the ultraviolet intensity of the disinfection space are finely calculated and designed, so that the cost is reduced to the greatest extent under the condition of meeting the microbe disinfection rate, and the result is reliable.

Description

Technical Field

[0001] The invention relates to a method for finely calculating the disinfecting rate of an ultraviolet disinfection device, and belongs to the technical field of ultraviolet disinfection. Background Art

[0002] In the detection of dust accumulation and bacteria content in air ducts of air-conditioning systems in more than 60 cities, 47.11% of the air ducts were severely polluted, 46.17% were moderately polluted, and only 6.12% were qualified.

[0003] For air-conditioning units, the performance of dynamic disinfection equipment can be said to be more demanding. The size of the disinfection equipment needs to be controlled, and a large area cannot be occupied for disinfection of indoor space where every inch of land is valuable. This requires improving the disinfection efficiency in a short period of time. The disinfection object in the air-conditioning unit is the contaminated airflow organization, and the chemical reagent acts on the contaminated surface. For high-efficiency filters, the resistance is large, which not only increases the energy consumption of the fan, but also easily causes water imbalance. For primary filters with smaller resistance, the sterilization effect is unsatisfactory. The most important problems faced by technologies such as plasma are safety and cost issues. Because plasma sterilization is still used on a small scale in China, the cost is often high. At the same time, in recent years, accidents caused by high voltage electricity have occurred from time to time, and safety issues are difficult to solve.

[0004] The advantages of ultraviolet disinfection technology are low cost, low resistance, easy installation and simple adjustment. However, the current use of ultraviolet disinfection technology often takes a long time to achieve good results. For dynamic disinfection in air-conditioning equipment, the contaminated air passes through the disinfection section in a short time. At present, there are few refined calculations and designs for disinfection equipment, and the dynamic disinfection effect is poor. To design new low-resistance and high-efficiency ultraviolet disinfection equipment, it is necessary to focus on improving disinfection efficiency, reducing construction costs, and improving the dynamic disinfection performance of air-conditioning systems. Summary of the invention

[0005] In order to achieve accurate control of the cost of a disinfection device, the invention specifically relates to a method for finely calculating the irradiation intensity of an ultraviolet disinfection device.

[0006] The technical solution adopted by the present invention is: a method for finely calculating the disinfecting rate of an ultraviolet disinfection device, the method comprising the following steps:

[0007] Step 1: Calculate the irradiation time according to the following formula:

[0008]

[0009] Where: t is the airflow disinfection time, V is the volume of the disinfection section, A is the cross-sectional area of ​​the air duct, V0 is the airflow velocity of the air duct, Q is the flow rate, and L is the length of the disinfection section;

[0010] Step 2: Given the initial standard mortality coefficient:

[0011] S(t)=e -kIt (2)

[0012] S is the survival percentage of bacteria exposed to ultraviolet light; k is the standard mortality constant, I is the ultraviolet radiation density, and t is the exposure time;

[0013] Step 3: Calculation of design irradiation intensity:

[0014] Designed irradiation intensity refers to the designed standard mortality rate k within the disinfection time t. i Under the condition of , the design disinfection rate is according to the formula:

[0015]

[0016] Calculate the design irradiation intensity under Ki conditions;

[0017] Step 4: Calculation of irradiation angle coefficient and gridding of disinfection space: According to the position relationship between the space point and the ultraviolet lamp, it is divided into the following three cases:

[0018] a) The spatial point is perpendicular to the end point of the UV lamp

[0019] The formula for the irradiance angle factor is:

[0020]

[0021]

[0022] X=(1+H) 2 +L 2 (7)

[0023] Y=(1-H) 2 +L 2 (8) Where: x is the distance from the spatial point to the lamp, l is the cross-sectional length of the lamp, and r is the radius of the lamp;

[0024] b) The spatial point is perpendicular to the non-end point of the UV lamp

[0025] The ultraviolet lamp is divided into two left and right cylinders perpendicular to the spatial point. The irradiation angle coefficient of the point is the sum of the angle coefficients of the two parts to the point. The irradiation angle coefficient formula is:

[0026] F 1-2 (x, l, r) = F d1-2 (x,l1,r)+F d2-2 (x,l2,r) (9)

[0027] Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet rays to the space point, F d1-2 (x, l1, r) is the irradiance angle coefficient of the left part of the ultraviolet light to this point, F d2-2 (x, l2, r) is the irradiance angle coefficient of the right part of the ultraviolet light to this point;

[0028] c) The spatial point is not perpendicular to the UV lamp. The UV lamp is virtually extended so that the end point of the extended UV lamp is perpendicular to the spatial point. The irradiation angle coefficient of the UV lamp to the spatial point is:

[0029] F 1-2 (x, l, r) = F d1-2 (x,l1,r)-F d2-2 (x,l2,r) (10)

[0030] Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet rays to the space point, F d1-2 (x, l1, r) is the irradiation angle coefficient of the solid part of the ultraviolet lamp to this point, F d2-2 (x, l2, r) is the irradiance angle coefficient of the virtual extension of the UV lamp to this point;

[0031] Grid of disinfection space: l direction is the airflow direction, x direction is perpendicular to the gas flow direction;

[0032]

[0033] F(x,l,r) is the irradiation angle coefficient of ultraviolet rays to the spatial point; dx is the grid length in the direction perpendicular to the gas flow; dl is the grid length in the direction perpendicular to the gas flow; α is the error coefficient; β is the error coefficient;

[0034] Step 5: Calculation of UV lamp output power

[0035] The irradiation intensity at a certain point in the disinfection space is proportional to the irradiation angle coefficient of the point and the output power of the lamp;

[0036]

[0037] Where: E Uv is the UV output power (W);

[0038]

[0039] Using the irradiation intensities I1 and I2 of the middle and front sections of a single UV irradiation intensity tube, calculate the irradiation output power E at two locations UV1 and E UV2Calculate the average output power of the two positions and record it as the calculated output power of the lamp E Uv ;

[0040] Step 6: Arrange the ultraviolet irradiation lamps and superimpose the space irradiation intensity:

[0041] By dividing the disinfection space into grids, calculate the irradiation intensity of each grid by a single ultraviolet disinfection lamp at different positions; after arranging N ultraviolet irradiation lamps in the disinfection space, calculate the ultraviolet irradiation intensity in each grid of the disinfection space, and calculate the average irradiation intensity in the disinfection space; Step 7: Experimentally test the actual survival rate of microorganisms:

[0042] Install the disinfection equipment in the actual air conditioning system; adjust the air supply speed to the design speed, use a six-stage impact microbial sampler to test the change in the concentration of microorganisms in the cross section before and after disinfection; at least three measuring points are evenly arranged on each test cross section; calculate the actual survival rate of microorganisms S(t) according to the following formula;

[0043]

[0044] S(t) is the actual survival rate of microorganisms; C1 is the concentration of microorganisms in the airflow before disinfection, and C2 is the concentration of microorganisms in the airflow after disinfection;

[0045] Step 8: Experimental effect iteration:

[0046] If the actual survival of the microorganism S(t) is less than 0.1, the calculation ends; if S(t) is greater than 0.1, the actual death constant k is calculated by the following formula: i+1 , and return to Step 3 to recalculate.

[0047]

[0048] The beneficial effects of the present invention are as follows: the ultraviolet radiation intensity of the disinfection space is finely calculated by gridding the disinfection space, accurately calculating the angular coefficient of each grid position, calculating the output power of the disinfection lamp, etc. Through actual testing, the microbial standard death constants of air-conditioning systems in different cities and different building types are iterated, and finally the present invention changes the current status of simple stacking of disinfection modules of microbial disinfection products, and finely calculates and designs the microbial disinfection rate of the disinfection product and the ultraviolet intensity of the disinfection space, and reduces the cost to the greatest extent under the condition of meeting the microbial disinfection rate, and the result is reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The overall flow chart of the method of the present invention is shown in FIG.

[0050] Figure 2This is the first type of relative position diagram of the calculation grid and the lamp tube.

[0051] Figure 3 This is the relative position diagram of the second calculation grid and the lamp tube.

[0052] Figure 4 This is the relative position diagram of the third calculation grid and the lamp tube.

[0053] Figure 5 A diagram of the size of the computational grid.

[0054] Figure 6 It is the distribution diagram of the angular coefficient of disinfection space of a single ultraviolet disinfection lamp.

[0055] Figure 7 It is a schematic diagram of the irradiation intensity test of a single ultraviolet disinfection lamp.

[0056] Figure 8 It is a schematic diagram of the actual disinfection rate test of the disinfection device. DETAILED DESCRIPTION

[0057] A specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0058] A method for finely calculating the disinfecting rate of an ultraviolet disinfection device, comprising the following steps: 1. Fine calculation process of ultraviolet lamps that meet the irradiation intensity required for disinfection

[0059] Step 1: Determine the size of the duct disinfection space based on the actual system volume and calculate the disinfection time t.

[0060] Step 2: Give the initial microbial standard death constant ki.

[0061] Step 3: Calculate the design irradiation intensity I when ki is the death constant, the disinfection time is t, and the microbial survival rate S(t) is 10%.

[0062] Step 4: Grid the disinfection space and calculate the angular coefficient of each grid corresponding to a single UV lamp.

[0063] Step 5: Calculate the output power of the lamp

[0064] Step 6: Arrange the number of ultraviolet lamps N, and calculate the irradiation intensity of each lamp in each grid of the disinfection space. Superimpose the irradiation intensity at each grid to make the average irradiation intensity of the disinfection space reach IStep 7: Experimental test, in a specific air conditioning system, the microbial survival rate S(t)

[0065] Step 8: If the actual microbial survival rate S(t) is less than 10%, the development is terminated. If the actual microbial survival rate S(t) is greater than 10%, recalculate the microbial standard death constant k at irradiation intensity I. i+1 . And return to Step 3.

[0066] 2. Calculation of the angular coefficient of the ultraviolet disinfection lamp in the disinfection space

[0067] The present invention makes a detailed calculation for a specific point in the disinfection space and two relative positions of the ultraviolet disinfection lamp. Figure 2 As shown, the irradiation intensity of the ultraviolet lamp at any point in space can be calculated using the irradiation angle coefficient formula of a finite length cylinder in the full set of irradiation angle coefficients for any infinitesimal element in space.

[0068]

[0069] Where: x is the distance from the space point to the lamp, (cm); l is the cross-sectional length of the lamp, (cm);

[0070] r is the radius of the lamp, (cm);

[0071] For Figure 3 In order to obtain the accurate irradiation angle coefficient of the point, the ultraviolet lamp should be divided into two left and right cylinders perpendicular to the point. The irradiation angle coefficient of the point is the sum of the angle coefficients of the two parts. In this case, the angle coefficient formula becomes:

[0072] F 1-2 (x,l,r)=F d1-2 (x,l1,r)+F d2-2 (x,l2,r) (2)

[0073] Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet rays to the space point; F d1-2 (x, l1, r) is the irradiance angle coefficient of the left part of the ultraviolet light to this point; F d2-2 (x, l2, r) is the irradiance angle coefficient of the right part of the ultraviolet light to this point.

[0074] And for Figure 4 In the case that the irradiation point is not in the space perpendicular to the UV lamp, in order to obtain the accurate irradiation angle coefficient of the UV lamp to this point, it is necessary to extend the UV lamp for a period of time so that the end point of the extended UV lamp can be perpendicular to the point. Then the irradiation angle coefficient of the UV lamp to this spatial point becomes:

[0075] F 1-2 (x, l, r) = F d1-2(x,l1,r)-F d2-2 (x,l2,r) (3)

[0076] Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet rays to the space point, F d1-2 (x, l1, r) is the irradiation angle coefficient of the solid part of the ultraviolet lamp to this point, F d2-2 (x, l2, r) is the irradiance angle coefficient of the virtual extended part of the ultraviolet lamp at this point.

[0077] 3. Grid division of disinfection space

[0078] The length of the grid of the disinfection space is divided into three directions, such as Figure 5 As shown, the l direction is the air flow direction, and the x direction is perpendicular to the gas flow direction.

[0079]

[0080] F(x, l, r) is the irradiance angle coefficient of ultraviolet rays to a spatial point;

[0081] d x is the grid length perpendicular to the gas flow direction;

[0082] dl is the grid length perpendicular to the gas flow direction;

[0083] α is the error coefficient, usually 0.05;

[0084] β is the error coefficient, usually 0.05;

[0085] like Figure 6 The three-dimensional distribution diagram of the angular coefficient of a single ultraviolet disinfection lamp in a certain size space. 4. Calculation of the output power of the ultraviolet air duct

[0086] like Figure 7 , fix two ultraviolet irradiators at 1000mm in the middle and the beginning of the lamp tube. After the ultraviolet disinfection lamp tube is preheated for 5 minutes, read the irradiation intensity of the ultraviolet disinfection lamp.

[0087]

[0088] Record the irradiation intensity I1 and I2 of the middle and front sections of a single UV irradiation intensity tube respectively, and calculate the irradiation output power E at the two positions UV1 and E UV2 , calculate the average output power at the two positions and record it as the calculated output power of the lamp tube.

[0089] Example 1

[0090] A method for finely calculating the disinfecting rate of an ultraviolet disinfection device comprises the following steps:

[0091] Step 1: Calculation of irradiation time.

[0092] Irradiation time refers to the time that the contaminated airflow is exposed to ultraviolet light when passing through the disinfection space. According to the following formula,

[0093]

[0094] Where: t is the airflow disinfection time, (s);

[0095] V is the volume of the disinfection section, (cm 3 );

[0096] A is the cross-sectional area of ​​the duct, (cm 2 );

[0097] V0 is the air flow velocity in the duct, (m / s);

[0098] Q is the flow rate, (m 3 / s)

[0099] L is the length of the disinfection section (m).

[0100] The airflow disinfection time is only related to the volume of the disinfection space and the flow rate of dirty gas. When the cross-sectional area of ​​the disinfection space is determined, the disinfection time is proportional to the length of the disinfection space and inversely proportional to the flow rate of the contaminated airflow. The disinfection space is based on the available space for building disinfection.

[0101] Step 2: Given the initial standard mortality coefficient:

[0102] The sterilization mechanism of ultraviolet irradiation is to cause chemical changes in nucleic acids, protoplasmic proteins and enzymes in microorganisms and bacteria, resulting in their death. It has a wide range of sterilization effects and can kill various microorganisms. Different types of microorganisms have different sensitivities to ultraviolet rays. Viruses and Gram-negative bacteria are the most sensitive, followed by Gram-positive bacteria, and then spores. Fungal spores have the strongest resistance. The mathematical expression of ultraviolet disinfection is:

[0103] S(t)=e -kIt (2)

[0104] S is the percentage of bacteria surviving under UV exposure;

[0105] k is the standard mortality constant, (cm 2 / (μW·s));

[0106] I is the ultraviolet radiation density, (μW / cm 2 );

[0107] t is the irradiation time, (s). ;

[0108] The selection of the standard mortality rate k determines the key parameter of the irradiation intensity required for disinfection. In engineering applications, it is difficult to select the size of k. The reason is that the comprehensive standard mortality rate of microorganisms of different types and proportions in the air is difficult to calculate, and even the k values ​​of the same type of microorganisms may vary greatly. The more accurate the initial standard mortality coefficient is, the fewer experimental iterations can be.

[0109] Step 3: Calculation of design irradiation intensity:

[0110] Designed irradiation intensity refers to the designed standard mortality rate k within the disinfection time t. i Under the condition of ki, the design disinfection rate is calculated according to formula (3) to calculate the design irradiation intensity under ki condition.

[0111]

[0112] Step 4: Calculation of irradiation angle coefficient and gridding of disinfection space:

[0113] The irradiance angle coefficient is the ratio of the irradiance energy emitted by a surface to the energy absorbed by another surface. It only defines the geometric relationship between the emitting surface and the receiving surface. If the energy emitted by the emitting surface is a constant value, and the receiving surface is a microelement surface at different positions, the irradiance angle coefficient can be used to calculate any irradiance intensity at different positions. The irradiance intensity of the ultraviolet lamp at any point in space can be calculated using the irradiance angle coefficient formula for any microelement in space for a finite length cylinder in the full set of irradiance angle coefficients.

[0114] X=(1+H) 2 +L 2 (7)

[0115] Y=(1-H) 2 +L 2 (8) Where: x is the distance from the space point to the lamp, (cm);

[0116] 1 is the cross-sectional length of the lamp, (cm);

[0117] r is the radius of the lamp, (cm);

[0118] For Figure 3 In order to obtain the accurate irradiation angle coefficient of the point, the ultraviolet lamp should be divided into two left and right cylinders perpendicular to the point. The irradiation angle coefficient of the point is the sum of the angle coefficients of the two parts. In this case, the angle coefficient formula becomes:

[0119] F 1-2 (x, l, r) = F d1-2(x,l1,r)+F d2-2 (x,l2,r) (9)

[0120] Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet light to the space point

[0121] F d1-2 (x, l1, r) is the irradiance angle coefficient of the left part of the ultraviolet light to this point

[0122] F d2-2 (x, l2, r) is the irradiance angle coefficient of the right part of the ultraviolet light to this point. Figure 4 In the case that the irradiation point is not in the space perpendicular to the UV lamp, in order to obtain the accurate irradiation angle coefficient of the UV lamp to this point, it is necessary to extend the UV lamp for a period of time so that the end point of the extended UV lamp can be perpendicular to the point. Then the irradiation angle coefficient of the UV lamp to this spatial point becomes:

[0123] F 1-2 (x, l, r) = F d1-2 (x,l1,r)-F d2-2 (x,l2,r) (10)

[0124] Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet rays to the space point, F d1-2 (x, l1, r) is the irradiation angle coefficient of the solid part of the ultraviolet lamp to this point, F d2-2 (x,l2,r) is the irradiance angle coefficient of the virtual extended part of the UV lamp to this point.

[0125] The length of the grid of the disinfection space is divided into three directions, such as Figure 5 As shown, the l direction is the air flow direction, and the x direction is perpendicular to the gas flow direction.

[0126]

[0127] F(x,l,r) is the irradiance angle coefficient of ultraviolet light to a spatial point;

[0128] dx is the grid length perpendicular to the gas flow direction;

[0129] dl is the grid length perpendicular to the gas flow direction;

[0130] α is the error coefficient, usually 0.05;

[0131] β is the error coefficient, usually 0.05;

[0132] In the formula, α and β are the error coefficients of grid division. The smaller the value, the denser the grid division, the greater the amount of calculation, and the higher the accuracy. The larger the value, the looser the grid division, the lower the amount of calculation, and the lower the accuracy. Step 5: Calculation of the output power of the ultraviolet lamp

[0133] As shown in the formula, the irradiation intensity at a certain position in the disinfection space is proportional to the angular coefficient of the lamp at that point and the output power of the lamp.

[0134]

[0135] Where: E UV UV output power (W)

[0136] In fact, the output power of ultraviolet disinfection is difficult to determine. Most manufacturers on the market can only give the input power of ultraviolet lamps. The output power of ultraviolet light is often unknown. The actual output power of the ultraviolet disinfection lamp can be calculated based on the measured value of the irradiation intensity at 1000mm, and then the designed disinfection device can be refined. Two ultraviolet irradiators are fixed at 1000mm in the middle and initial sections of the lamp tube. After the ultraviolet disinfection lamp tube is preheated for 5 minutes, read the irradiation intensity of the ultraviolet disinfection lamp.

[0137]

[0138] Record the irradiation intensity I1 and I2 of the middle and front sections of a single UV irradiation intensity tube respectively, and calculate the irradiation output power E at the two positions UV1 and E UV2 , calculate the average output power at the two positions and record it as the calculated output power of the lamp tube.

[0139] Step 6: Arrange the ultraviolet irradiation lamps and superimpose the space irradiation intensity:

[0140] The ultraviolet light sources on the market are usually "incoherent light sources". The light emitted by incoherent light sources not only has different wavelengths, but also different phases and amplitudes, so there will be no interference. Therefore, the ultraviolet light intensity generated by different lamps can be regarded as a scalar superposition calculation. By dividing the disinfection space into grids, the irradiation intensity of a single ultraviolet disinfection lamp at different positions on each grid is calculated separately. Then the superposition operation is performed.

[0141] After arranging N ultraviolet irradiation lamps in the disinfection space, calculate the ultraviolet irradiation intensity in each grid of the disinfection space, and calculate the average irradiation intensity in the disinfection space.

[0142] Step 7: Experimental test of actual survival rate of microorganisms:

[0143] Install the disinfection equipment in the actual air conditioning system. Adjust the air supply speed to the design speed and the air supply temperature to 20℃ (±0.5℃). Use a six-stage impact microbial sampler to test the change in the concentration of microorganisms in the cross section before and after disinfection. At least three measuring points are evenly arranged on each test cross section. Calculate the actual survival rate of microorganisms S(t) according to the following formula.

[0144]

[0145] S(t) is the actual survival rate of microorganisms;

[0146] C1 is the concentration of microorganisms in the airflow before disinfection (CFU / m 3 );

[0147] C2 is the concentration of microorganisms in the airflow after disinfection (CFU / m 3 ).

[0148] Step 8: Experimental effect iteration:

[0149] If the actual survival of the microorganism S(t) is less than 0.1, the calculation ends. If S(t) is greater than 0.1, the actual death constant k is calculated by the following formula: i+1 , and return to step 3 to recalculate.

[0150]

[0151] The above are only embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for finely calculating the disinfecting rate of an ultraviolet disinfection device, characterized in that: The method comprises the steps of: Step 1: Calculate the irradiation time according to the following formula: Where: t is the airflow disinfection time, V is the volume of the disinfection section, A is the cross-sectional area of ​​the air duct, V0 is the airflow velocity of the air duct, Q is the flow rate, and L is the length of the disinfection section; Step 2: Given the initial standard mortality coefficient: S(t)=e -kIt (2) S is the survival percentage of bacteria exposed to ultraviolet light; k is the standard mortality constant, I is the ultraviolet radiation density, and t is the exposure time; Step 3: Calculation of design irradiation intensity: Designed irradiation intensity refers to the designed standard mortality rate k within the disinfection time t. i Under the condition of , the design disinfection rate is according to the formula: Calculate the design irradiation intensity under Ki conditions; Step 4: Calculation of irradiation angle coefficient and gridding of disinfection space: According to the position relationship between the space point and the ultraviolet lamp, it is divided into the following three cases: a) The spatial point is perpendicular to the end point of the UV lamp The formula for the irradiance angle factor is: X=(1+H) 2 +L 2 (7) Y=(1-H) 2 +L 2 (8) Where: x is the distance from the spatial point to the lamp, l is the cross-sectional length of the lamp, and r is the radius of the lamp; b) The spatial point is perpendicular to the non-end point of the UV lamp The ultraviolet lamp is divided into two left and right cylinders perpendicular to the spatial point. The irradiation angle coefficient of the point is the sum of the angle coefficients of the two parts to the point. The irradiation angle coefficient formula is: F 1-2 (x,l,r)=F d1-2 (x,l1,r)+F d2-2 (x,l2,r) (9) Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet light to the space point, F d1-2 (x,l1,r) is the irradiance angle coefficient of the left part of the ultraviolet light to this point, F d2-2 (x,l2,r) is the irradiance angle coefficient of the right part of the ultraviolet light to this point; c) The spatial point is not perpendicular to the UV lamp The ultraviolet lamp is virtually extended so that the end point of the extended ultraviolet lamp is perpendicular to the spatial point. The irradiation angle coefficient of the ultraviolet lamp to the spatial point is: F 1-2 (x,l,r)=F d1-2 (x,l1,r)-F d2-2 (x,l2,r) (10) Among them: F 1-2 (x, l, r) is the irradiance angle coefficient of ultraviolet light to the space point, F d1-2 (x,l1,r) is the irradiation angle coefficient of the solid part of the UV lamp to this point, F d2-2 (x,l2,r) is the irradiance angle coefficient of the virtual extension of the UV lamp to this point; Grid of disinfection space: l direction is the airflow direction, x direction is perpendicular to the gas flow direction; F(x,l,r) is the irradiation angle coefficient of ultraviolet rays to the spatial point; dx is the grid length in the direction perpendicular to the gas flow; dl is the grid length in the direction perpendicular to the gas flow; α is the error coefficient; β is the error coefficient; Step 5: Calculation of UV lamp output power The irradiation intensity at a certain point in the disinfection space is proportional to the irradiation angle coefficient of the point and the output power of the lamp; Where: E UV is the UV output power (W); Using the irradiation intensities I1 and I2 of the middle and front sections of a single UV irradiation intensity tube, calculate the irradiation output power E at two locations UV1 and E UV2 Calculate the average output power of the two positions and record it as the calculated output power of the lamp E UV ; Step 6: Arrange the ultraviolet irradiation lamps and superimpose the space irradiation intensity: By dividing the disinfection space into grids, calculate the irradiation intensity of each grid by a single ultraviolet disinfection lamp at different positions; after arranging N ultraviolet irradiation lamps in the disinfection space, calculate the ultraviolet irradiation intensity in each grid of the disinfection space, and calculate the average irradiation intensity in the disinfection space; Step 7: Experimentally test the actual survival rate of microorganisms: Install the disinfection equipment in the actual air conditioning system; adjust the air supply speed to the design speed, use a six-stage impact microbial sampler to test the change in the concentration of microorganisms in the cross section before and after disinfection; at least three measuring points are evenly arranged on each test cross section; calculate the actual survival rate of microorganisms S(t) according to the following formula; S(t) is the actual survival rate of microorganisms; C1 is the concentration of microorganisms in the airflow before disinfection, and C2 is the concentration of microorganisms in the airflow after disinfection; Step 8: Experimental effect iteration: If the actual survival of the microorganism S(t) is less than 0.1, the calculation ends; If S(t) is greater than 0.1, the actual death constant k can be calculated by the above formula: i+1 , and return to Step 3 to recalculate.

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