Method for evaluating purification efficiency of air purifier for removing benzene series pollutants

Abstract

The application discloses a kind of air purifier removal benzene series pollutant's purification efficiency evaluation method suitable for, through collecting the initial concentration of benzene series pollutant in blank cabin and test cabin, and the initial concentration in test cabin;After starting prototype effect, the final concentration of benzene series pollutant in blank cabin and test cabin is collected respectively, and the final concentration in test cabin, the natural attenuation rate of benzene series pollutant is calculated by the initial concentration of benzene series pollutant in blank cabin and the final concentration of benzene series pollutant, the theoretical conversion concentration in test cabin is calculated by the initial concentration of benzene series pollutant in test cabin and the final concentration of benzene series pollutant and the natural attenuation rate of benzene series pollutant, and the conversion rate is calculated by the initial concentration and the final concentration in test cabin and the theoretical conversion concentration, according to conversion rate to evaluate the green purification efficiency of air purifier removal benzene series pollutant.

Description

Technical Field

[0001] This invention relates to the field of air purifier purification efficiency evaluation, and in particular to a green purification efficiency evaluation method applicable to air purifiers for removing benzene-based pollutants. Background Technology

[0002] With the continuous improvement of living standards, people have increasingly higher demands for the decoration of indoor environments such as offices and residences. A large number of chemically synthesized building materials are widely used, while various cosmetics and fragrances have gradually become indispensable daily necessities. These products directly or indirectly release various pollutants, easily leading to indoor air pollution. Among them, benzene compounds are highly toxic, exhibiting strong toxicity to the human respiratory and nervous systems. Therefore, they have been included in my country's indoor air quality standards, becoming one of the important evaluation indicators for indoor air pollution.

[0003] To effectively improve indoor air quality, domestic and international companies have successively developed and produced various types of air purifiers, which can be broadly categorized according to their purification principles into physical adsorption, mechanical filtration, plasma technology, and photocatalysis. Due to its advantages of rapid effectiveness, low cost, minimal technological requirements, and ease of production, physical adsorption is the dominant method in commercially available air purifiers. However, physical adsorption only provides a short-term purification effect for benzene-based pollutants; it does not irreversibly degrade the pollutants at the source, thus easily leading to secondary pollution release. Conversely, reactive degradation purification principles can fundamentally degrade benzene-based pollutants into CO2 and H2O, achieving a truly green purification effect. Furthermore, it is environmentally friendly and eliminates the potential risk of secondary pollution, making it highly popular among consumers.

[0004] Currently, domestic and international testing standards for air purifier performance cannot differentiate between physical adsorption and reactive degradation methods for evaluating the purification performance of gaseous pollutants. Furthermore, there is no specific testing method for evaluating the green purification efficiency of air purifiers in removing gaseous pollutants. This clearly hinders the accurate evaluation of the green purification performance of air purifier products, undoubtedly limiting the healthy and orderly development of the air purification industry. Therefore, researching and exploring suitable testing and evaluation methods for the green purification efficiency of air purifiers in removing gaseous pollutants has significant theoretical and practical implications. Summary of the Invention

[0005] The purpose of this invention is to provide a method for evaluating the green purification efficiency of air purifiers in removing benzene-based pollutants by introducing CO2 conversion rate as an evaluation index of the green purification effect of air purifiers. This method is applicable to accurately and objectively evaluating the green purification efficiency of air purifiers in removing benzene-based pollutants, filling the gap in domestic testing methods in this field, and providing data support for enterprise product research and development and production.

[0006] The purification efficiency evaluation method for removing benzene series pollutants by air purifiers according to the present invention includes the following steps:

[0007] S1. Select two adjacent experimental chambers with the same performance parameters as blank chamber and test chamber respectively;

[0008] S2. Place the air purifier prototype into the test chamber. After the prototype is tested and found to be running normally, turn off the prototype and seal the test chamber. Use the blank chamber as a blank control.

[0009] S3. Generate equal amounts of benzene-based pollutants in the blank chamber and the test chamber using a gas generator, turn on the stirring fan to stir, then turn off the stirring fan and let it stand for a period of time.

[0010] S4. Collect the initial concentrations of benzene series pollutants in the blank chamber and the test chamber, as well as the initial concentration of CO2 in the test chamber;

[0011] S5. Determine whether the initial concentration of benzene series pollutants in the blank chamber and the test chamber is less than the preset deviation value. Otherwise, return to step S3. If yes, start the prototype and after a period of time, collect the final concentration of benzene series pollutants in the blank chamber and the test chamber, and the final concentration of CO2 in the test chamber.

[0012] S6. Subtract the final concentration of benzene series pollutants from the initial concentration of benzene series pollutants in the blank chamber, and then divide by the initial concentration of benzene series pollutants to calculate the natural decay rate of benzene series pollutants.

[0013] S7. Determine whether the natural decay rate of benzene pollutants is less than the preset value. Otherwise, return to step S3. If yes, multiply the initial concentration of benzene pollutants in the test chamber by (1 - natural decay rate of benzene pollutants) and subtract the final concentration of benzene pollutants to calculate the theoretical CO2 conversion concentration in the test chamber.

[0014] S8. Subtract the initial CO2 concentration from the final CO2 concentration in the test chamber and then divide by the theoretical CO2 conversion concentration to calculate the CO2 conversion rate. Evaluate the purification efficiency of the air purifier in removing benzene pollutants based on the CO2 conversion rate.

[0015] As a preferred embodiment of the present invention, a green purification efficiency grading evaluation table for air purifiers to remove benzene series pollutants is established. The green purification efficiency grading evaluation table is divided into CO2 conversion rate intervals based on the CO2 conversion rate value. Each CO2 conversion rate interval corresponds to an air purifier performance level. The green purification efficiency of air purifiers in removing benzene series pollutants is graded and evaluated based on the air purifier performance level corresponding to the CO2 conversion rate interval in which the CO2 conversion rate is located.

[0016] As a preferred embodiment of the present invention, in step S7, the initial concentration of benzene pollutants in the test chamber is multiplied by (1 - natural decay rate of benzene pollutants) and the final concentration of benzene pollutants is subtracted. Then, the mass concentration is converted into the volume fraction under standard conditions (0°C, 101.325 kPa). Finally, it is multiplied by the number of carbon molecules in the benzene series to calculate the theoretical CO2 conversion concentration in the test chamber.

[0017] In a preferred embodiment of the present invention, after calculating the CO2 conversion rate in step S8, the process returns to step S1 and repeats multiple times. The CO2 conversion rates obtained multiple times are calculated to obtain the average CO2 conversion rate, and the purification efficiency of the air purifier in removing benzene pollutants is evaluated based on the average CO2 conversion rate.

[0018] As a preferred embodiment of the present invention, the stirring fan is turned on for stirring, and then the stirring fan is turned off and left to stand for a period of time. Specifically, the stirring fan is turned on for 2 to 10 minutes, and then left to stand for 10 to 30 minutes.

[0019] As a preferred embodiment of the present invention, the preset deviation value is 5%.

[0020] As a preferred embodiment of the present invention, the preset value is 5%.

[0021] The beneficial effects of this invention are as follows:

[0022] The purification efficiency evaluation method for removing benzene series pollutants by air purifiers, as described in this invention, involves selecting two adjacent experimental chambers with identical performance parameters as a blank chamber and a test chamber, respectively. Equal amounts of benzene series pollutants are generated in both chambers using a gas generator. A stirring fan is activated for agitation, then the fan is turned off, and the chambers are left to stand for a period of time. The initial concentrations of benzene series pollutants in the blank chamber and the test chamber, and the initial concentration of CO2 in the test chamber, are collected. After the prototype is activated, the final concentrations of benzene series pollutants in the blank chamber and the test chamber, and the final concentration of CO2 in the test chamber, are collected again. The natural decay rate of benzene series pollutants is calculated using the initial and final concentrations in the blank chamber, and the theoretical conversion concentration of CO2 in the test chamber is calculated using the initial and final concentrations and the natural decay rate. Finally, the CO2 conversion rate is calculated using the initial and final concentrations and the theoretical conversion rate. The CO2 conversion rate is then used to evaluate the purification efficiency of air purifiers. This study aims to accurately and objectively evaluate the green purification efficiency of air purifiers in removing benzene-based pollutants. This not only fills a gap in domestic testing methods in this field, providing data support for product development and production, but also helps consumers choose suitable air purifiers. Furthermore, by determining whether the initial concentration of benzene-based pollutants in the blank and test chambers is less than a preset deviation value, and if so, after the prototype has been running for a period of time, the final concentrations of benzene-based pollutants in the blank and test chambers, and the final CO2 concentration in the test chamber, can be collected to further accurately and objectively evaluate the green purification efficiency of the air purifier for benzene-based pollutants. Additionally, by determining whether the natural decay rate of benzene-based pollutants is less than a preset value, and if so, multiplying the initial concentration of benzene-based pollutants in the test chamber by (1 - natural decay rate of benzene-based pollutants) and subtracting the final concentration of benzene-based pollutants, the theoretical conversion concentration of CO2 in the test chamber can be calculated, further enabling an accurate and objective evaluation of the green purification efficiency of the air purifier for benzene-based pollutants. Attached Figure Description

[0023] Figure 1 This is a schematic flowchart of a green purification efficiency evaluation method for removing benzene-based pollutants from air purifiers, according to the present invention. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] A method for evaluating the purification efficiency of air purifiers in removing benzene series pollutants is proposed. Toluene is selected as the target pollutant, the test sample is a household air purifier, and the experimental chamber size is 30m². 3 ,like Figure 1 As shown, it includes:

[0027] S1. Select two adjacent 30m sections with the same performance parameters. 3 The experimental chamber serves as both a blank chamber and a test chamber. The temperature and humidity control system and clean air supply system within the chamber regulate the testing environment to the following conditions: temperature 20–26℃, humidity 40–60% RH, and background air particle concentration <1000 L / min. -1 CO2 concentration ≤ 0.10% (volume fraction), toluene concentration ≤ 0.20 mg / m³ 3 .

[0028] S2. Place the household air purifier prototype in the center of the test chamber. After the prototype is tested and found to be running normally, turn off the prototype and seal the test chamber. At the same time, turn off the temperature and humidity control system and the clean air supply system. Use the blank chamber as a blank control.

[0029] S3. Generate 0.83 mL of toluene solution (chromatographic grade) in the blank chamber and the test chamber respectively using a gas generator. Turn on the stirring fan and stir for 5 minutes to mix the pollutants in the chamber evenly. Then turn off the stirring fan and let it stand for 20 minutes.

[0030] S4. Initial concentrations of toluene contaminants in the blank chamber and experimental chamber were collected using Tenax-TA adsorption tubes at a flow rate of 0.2 L / min and a sampling volume of 2 L. Simultaneously, the initial CO2 concentration in the experimental chamber was measured using a non-dispersive infrared CO2 analyzer. The initial toluene concentration was controlled within the range of 16 mg / m³. 3 ~24mg / m 3 The initial CO2 concentration is ≤0.10% (volume fraction).

[0031] S5. Determine whether the initial concentration of toluene contaminants in the blank chamber and the test chamber is less than the preset deviation value. The preset deviation value is 5%. If it is less than 5%, turn on the prototype for 30 minutes, and then use Tenax-TA adsorption tubes to collect the final concentration of toluene contaminants in the blank chamber and the test chamber respectively. The sampling flow rate is 0.2L / min and the sampling volume is 4L. At the same time, use a non-dispersive infrared CO2 analyzer to determine the final concentration of CO2 in the test chamber.

[0032] S6. Subtract the final toluene contaminant concentration b from the initial toluene contaminant concentration b0 in the blank chamber. t Then, by dividing by the initial concentration of toluene pollutant b0, the natural decay rate N of toluene pollutant is calculated, as follows:

[0033] S7. Determine whether the natural decay rate of toluene pollutants is less than the preset value, which is 5%. If it is less than 5%, multiply the initial concentration of toluene pollutants B0 in the test chamber by (1-N) and subtract the final concentration of toluene pollutants B. t The theoretical CO2 conversion concentration C in the experimental chamber was calculated. r In order to increase the theoretical CO2 conversion concentration C r The accuracy is determined by multiplying the initial toluene contaminant concentration B0 in the test chamber by (1-N) and then subtracting the final toluene contaminant concentration B. t Then, the mass concentration is converted to a volume fraction under standard conditions (0℃, 101.325kPa), and finally multiplied by the number of carbon atoms in the benzene series molecules to calculate the theoretical CO2 conversion concentration C in the experimental chamber. r The formula is as follows:

[0034] Where 22.4 is the molar volume of the gas under standard conditions (0℃, 101.325kPa); 273.15 is the absolute temperature under standard conditions (0℃, 101.325kPa); T is the ambient temperature inside the test chamber; M is the relative molecular mass of the benzene series compound; P is the atmospheric pressure inside the test chamber; and n is the number of carbon atoms in the benzene series molecule (e.g., for toluene, n is 7).

[0035] S8. Set the final CO2 concentration C in the test chamber. t Subtract the initial CO2 concentration C0 and then divide by the theoretical CO2 conversion concentration C. r The CO2 conversion rate is calculated, and the purification efficiency of the air purifier in removing benzene-based pollutants is evaluated based on the CO2 conversion rate; the formula is as follows: The collected toluene samples were analyzed by secondary thermal desorption-gas chromatography, and the initial concentrations of toluene contaminants in the blank chamber and the test chamber were found to be 22.15 mg / m³. 3 and 21.56 mg / m 3 The final concentrations were 21.58 mg / m³. 3 and 0.37 mg / m 3 The natural decay rate of toluene pollutants in the blank chamber was calculated to be 2.57%, and the initial concentration deviation between the two experimental chambers was 2.70%, indicating that the experiment was successful. At the same time, under the conditions of ambient temperature of 25.5℃ and atmospheric pressure of 101.316kPa in the experimental chamber, the CO2 conversion rate was calculated to be 76.18% based on the initial CO2 concentration of 0.026% and the final concentration of 0.319% in the experimental chamber. This means that the green purification efficiency of the prototype in the experimental chamber for toluene pollutants is 76.18%.

[0036] A green purification efficiency grading evaluation table for air purifiers to remove benzene series pollutants was established, as shown in Table 1. The table divides CO2 conversion rate intervals according to the CO2 conversion rate value. Each CO2 conversion rate interval corresponds to an air purifier performance level. The green purification efficiency of air purifiers in removing benzene series pollutants is graded and evaluated based on the air purifier performance level corresponding to the CO2 conversion rate interval in which the CO2 conversion rate falls.

[0037] Table 1:

[0038]

[0039] According to the green purification efficiency rating table for air purifiers removing benzene-related pollutants, the prototype in the test chamber has a green purification efficiency of 76.18% for toluene pollutants, which is rated as AAA.

[0040] Example 2

[0041] A method for evaluating the purification efficiency of air purifiers in removing benzene series pollutants is proposed. Toluene is selected as the target pollutant, the test sample is an air purifier for passenger vehicles, and the experimental chamber space is 3m². 3 ,like Figure 1 As shown, it includes:

[0042] S1. Select two adjacent 3m sections with the same performance parameters. 3 The experimental chamber serves as both a blank chamber and a test chamber. The temperature and humidity control system and clean air supply system within the chamber regulate the testing environment to the following conditions: temperature 20–26℃, humidity 40–60% RH, and background air particle concentration <1000 L / min. -1 CO2 concentration ≤ 0.10% (volume fraction), toluene concentration ≤ 0.20 mg / m³ 3 .

[0043] S2. Place the prototype of the passenger car air purifier in the center of the test chamber. After the prototype is tested and found to be running normally, turn off the prototype and seal the test chamber. At the same time, turn off the temperature and humidity control system and the clean air supply system. Use the blank chamber as a blank control.

[0044] S3. Generate 83 μL of toluene solution (chromatographic grade) in the blank chamber and the test chamber respectively using a gas generator. Turn on the stirring fan for 3 minutes to mix the pollutants in the chamber evenly, then turn off the stirring fan and let it stand for 10 minutes.

[0045] S4. Initial concentrations of toluene contaminants in the blank chamber and experimental chamber were collected using Tenax-TA adsorption tubes at a flow rate of 0.2 L / min and a sampling volume of 2 L. Simultaneously, the initial CO2 concentration in the experimental chamber was measured using a non-dispersive infrared CO2 analyzer. The initial toluene concentration was controlled within the range of 16 mg / m³. 3 ~24mg / m 3 The initial CO2 concentration is ≤0.10% (volume fraction).

[0046] S5. Determine whether the initial concentration of toluene contaminants in the blank chamber and the test chamber is less than the preset deviation value. The preset deviation value is 5%. If it is less than 5%, turn on the prototype for 30 minutes, and then use Tenax-TA adsorption tubes to collect the final concentration of toluene contaminants in the blank chamber and the test chamber respectively. The sampling flow rate is 0.2L / min and the sampling volume is 4L. At the same time, use a non-dispersive infrared CO2 analyzer to determine the final concentration of CO2 in the test chamber.

[0047] S6. Subtract the final toluene contaminant concentration b from the initial toluene contaminant concentration b0 in the blank chamber. t Then, by dividing by the initial concentration of toluene pollutant b0, the natural decay rate N of toluene pollutant is calculated, as follows:

[0048] S7. Determine whether the natural decay rate of toluene pollutants is less than the preset value, which is 5%. If it is less than 5%, multiply the initial concentration of toluene pollutants B0 in the test chamber by (1-N) and subtract the final concentration of toluene pollutants B. t The theoretical CO2 conversion concentration C in the experimental chamber was calculated. r In order to increase the theoretical CO2 conversion concentration C r The accuracy is determined by multiplying the initial toluene contaminant concentration B0 in the test chamber by (1-N) and then subtracting the final toluene contaminant concentration B. t Then, the mass concentration is converted to a volume fraction under standard conditions (0℃, 101.325kPa), and finally multiplied by the number of carbon atoms in the benzene series molecules to calculate the theoretical CO2 conversion concentration C in the experimental chamber. r The formula is as follows:

[0049] Where 22.4 is the molar volume of the gas under standard conditions (0℃, 101.325kPa); 273.15 is the absolute temperature under standard conditions (0℃, 101.325kPa); T is the ambient temperature inside the test chamber; M is the relative molecular mass of the benzene series compound; P is the atmospheric pressure inside the test chamber; and n is the number of carbon atoms in the benzene series molecule (e.g., for toluene, n is 7).

[0050] S8. Set the final CO2 concentration C in the test chamber. tSubtract the initial CO2 concentration C0 and then divide by the theoretical CO2 conversion concentration C. r The CO2 conversion rate is calculated, and the purification efficiency of the air purifier in removing benzene-based pollutants is evaluated based on the CO2 conversion rate; the formula is as follows: The collected toluene samples were analyzed by secondary thermal desorption-gas chromatography, and the initial concentrations of toluene contaminants in the blank chamber and the experimental chamber were found to be 22.45 mg / m³. 3 and 21.81 mg / m 3 The final concentrations were 22.01 mg / m³. 3 and 0.13 mg / m 3 The natural decay rate of toluene pollutants in the blank chamber was calculated to be 1.96%, and the initial concentration deviation between the two experimental chambers was 2.89%, indicating that the experiment was successful. Simultaneously, under the conditions of an ambient temperature of 25.1℃ and an atmospheric pressure of 101.320 kPa in the experimental chamber, with an initial CO2 concentration of 0.031% and a final concentration of 0.380%, the CO2 conversion rate was calculated to be 88.23%, meaning the green purification efficiency of the prototype in the experimental chamber for toluene pollutants was 88.23%. According to Table 1, the green purification efficiency rating for removing benzene pollutants by air purifiers, the performance level of the prototype in the experimental chamber with a green purification efficiency of 88.23% for toluene pollutants is AAAA.

[0051] The above embodiments are only used to illustrate the detailed solutions of the present invention. The present invention is not limited to the above detailed solutions, that is, it does not mean that the present invention must rely on the above detailed solutions to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., are all within the protection scope and disclosure scope of the present invention.

Claims

1. A method for evaluating the purification efficiency of air purifiers in removing benzene series pollutants, characterized in that, Includes the following steps: S1. Select two adjacent experimental chambers with the same performance parameters as blank chamber and test chamber respectively; S2. Place the air purifier prototype into the test chamber. After the prototype is tested and found to be running normally, turn off the prototype and seal the test chamber. Use the blank chamber as a blank control. S3. Generate equal amounts of benzene-based pollutants in the blank chamber and the test chamber using a gas generator, turn on the stirring fan to stir, then turn off the stirring fan and let it stand for a period of time. S4. Collect the initial concentrations of benzene series pollutants in the blank chamber and the test chamber, as well as the initial concentration of CO2 in the test chamber; S5. Determine whether the initial concentrations of benzene series pollutants in the blank chamber and the test chamber are less than the preset deviation value. Otherwise, return to step S3. If yes, start the prototype and operate for a period of time, then collect the final concentrations of benzene series pollutants in the blank chamber and the test chamber, and the final concentration of CO2 in the test chamber, respectively. S6. Subtract the final concentration of benzene series pollutants from the initial concentration of benzene series pollutants in the blank chamber, and then divide by the initial concentration of benzene series pollutants to calculate the natural decay rate of benzene series pollutants. S7. Determine whether the natural decay rate of benzene series pollutants is less than the preset value. Otherwise, return to step S3. If yes, multiply the initial concentration of benzene series pollutants in the test chamber by (1 - natural decay rate of benzene series pollutants) and subtract the final concentration of benzene series pollutants. Then, convert the mass concentration into the volume fraction under standard conditions and finally multiply it by the number of carbon molecules in the benzene series to calculate the theoretical CO2 conversion concentration in the test chamber. The standard conditions are 0℃ and 101.325kPa. S8. Subtract the initial CO2 concentration from the final CO2 concentration in the test chamber and then divide by the theoretical CO2 conversion concentration to calculate the CO2 conversion rate. Evaluate the purification efficiency of the air purifier in removing benzene pollutants based on the CO2 conversion rate.

2. The method for evaluating the purification efficiency of air purifiers for removing benzene series pollutants according to claim 1, characterized in that, A green purification efficiency grading evaluation table for air purifiers in removing benzene series pollutants was established. The table divides CO2 conversion rate ranges based on CO2 conversion rate values, with each range corresponding to an air purifier performance level. The green purification efficiency of air purifiers in removing benzene series pollutants is graded and evaluated based on the performance level of the air purifier corresponding to the CO2 conversion rate range it falls within.

3. The method for evaluating the purification efficiency of air purifiers for removing benzene series pollutants according to claim 1, characterized in that, After calculating the CO2 conversion rate in step S8, return to step S1 and repeat multiple times. Calculate the average CO2 conversion rate obtained from multiple calculations and evaluate the air purifier's purification efficiency in removing benzene-based pollutants based on the average CO2 conversion rate.

4. The method for evaluating the purification efficiency of air purifiers for removing benzene series pollutants according to claim 1, characterized in that, Turn on the stirring fan to stir, then turn off the stirring fan and let it stand for a period of time. Specifically, turn on the stirring fan to stir for 2 to 10 minutes, then let it stand for 10 to 30 minutes.

5. The method for evaluating the purification efficiency of air purifiers for removing benzene series pollutants according to claim 1, characterized in that, The preset deviation value is 5%.

6. The method for evaluating the purification efficiency of air purifiers for removing benzene series pollutants according to claim 1, characterized in that, The default value is 5%.

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