Method for calculating pressure loss of woven air filter screen and medium

Abstract

The invention belongs to the technical field of air filtration, and particularly relates to a method and medium for calculating the pressure loss of a woven air filter screen, and the method comprises the following steps: obtaining the number of filaments per centimeter in the warp direction and the weft direction in the filter screen and the diameter of the filaments in the filter screen, and calculating the aperture ratio eta of the filter screen; calculating the reference pressure loss P0 of the filter screen at the reference wind speed V0 according to the aperture opening ratio eta; and according to the aperture opening ratio eta, the reference pressure loss P0 and a set target wind speed V, calculating the actual pressure loss P of the filter screen at the target wind speed V. Compared with the prior art, the problems that in the prior art, the pressure loss needs to be measured based on experiments or calculated through experimental data, the obtaining process is tedious, consumed time is long, and cost is high are solved. According to the scheme, the corresponding pressure loss of the filter screen can be calculated according to the design density of the filter screen and the target wind speed, so that a large amount of time and materials can be saved for technicians during structural design and optimization of the filter screen, and the speed and efficiency of product iteration upgrading are further improved.

Description

Technical Field

[0001] This invention belongs to the field of air filtration technology, specifically relating to a method and medium for calculating the pressure loss of woven air filter screens. Background Technology

[0002] Woven filters are important components of air conditioners, fresh air systems, and other complete products, and mainly serve to filter airborne dust.

[0003] In the use of woven filter screens, pressure loss and filtration efficiency are the main performance indicators. However, pressure loss and filtration efficiency are often contradictory; specifically, higher filter efficiency usually leads to higher pressure loss, resulting in greater energy consumption and noise in the overall product. Therefore, engineers need to balance the relationship between pressure loss and filtration effect during the structural development, design, and optimization of woven filter screens.

[0004] For filter screens, pressure loss mainly stems from their structural characteristics, including porosity, mesh count, filament diameter, weaving method, surface roughness, and thickness, exhibiting high complexity and high coupling. Therefore, the primary method for obtaining filter screen pressure loss currently involves directly testing the raw materials after spinning and weaving to determine the pressure loss value for the corresponding structural design, as illustrated in CN108224554A, where the current pressure loss of the filter screen is obtained through measurement by the first acquisition unit. However, this testing method is cumbersome, time-consuming, and wastes a significant amount of raw materials, resulting in high design costs.

[0005] In addition, some existing technologies, such as CN110529976A and CN113521893A, have proposed detection methods for filter life and clogging. However, these solutions also require calculation and judgment based on product test results. They cannot calculate the pressure loss of the corresponding filter based on the set parameters and structural parameters. For the structural design and optimization stage, there are still drawbacks such as cumbersome process, long time consumption, and waste of a lot of raw materials, resulting in high design costs. Summary of the Invention

[0006] The purpose of this invention is to provide a method and medium for calculating the pressure loss of woven air filters, thereby addressing at least one of the aforementioned problems. This solves the problem in existing technologies where pressure loss requires experimental measurement or calculation based on experimental data, resulting in a cumbersome, time-consuming, and costly process. This solution can calculate the corresponding pressure loss based on the filter's design density and target wind speed, thus saving technicians significant time and materials during filter structure design and optimization, further improving the speed and efficiency of product iteration and upgrades.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] The first aspect of this invention discloses a method for calculating the pressure loss of a woven air filter, comprising the following steps:

[0009] S1: Obtain the aperture ratio η:

[0010] Obtain the number of filaments per centimeter in the warp and weft directions of the filter screen, as well as the diameter of the filaments in the filter screen, and calculate the opening ratio η of the filter screen;

[0011] S2: Obtain the baseline pressure drop P0:

[0012] Calculate the reference pressure loss P0 of the filter screen at the reference wind speed V0 based on the opening ratio η;

[0013] S3: Obtain the actual pressure loss P:

[0014] Based on the opening ratio η obtained in step S1, the reference pressure loss P0 obtained in step S2, and the set target wind speed V, calculate the actual pressure loss P of the filter screen at the target wind speed V.

[0015] Preferably, in step S1, the aperture ratio η is calculated using the following formula:

[0016] η=(10-A×D / 100)×(10-B×D / 100) / (10×10)×100%;

[0017] In the formula:

[0018] A represents the number of warp filaments per centimeter in the filter screen;

[0019] B represents the number of filaments per centimeter in the weft direction of the filter screen;

[0020] D is 100 times the diameter of the wires in the filter screen, in millimeters.

[0021] Preferably, in step S2, the reference pressure loss P0 is a logarithmic function related to the aperture ratio η, and the reference pressure loss P0 is calculated by the following formula:

[0022] P0 = a × ln(η) + b;

[0023] In the formula:

[0024] a and b are both constants.

[0025] Preferably, in step S2, the reference wind speed V0 is 2.5 m / s;

[0026] The reference pressure loss P0 is calculated using the following formula:

[0027] P0 = -19.39 × ln(η) - 2.2359.

[0028] Preferably, in step S3, the actual pressure loss P is calculated using the following formula:

[0029] P = K × P0 × V / V0;

[0030] In the formula:

[0031] K is a coefficient.

[0032] Preferably, in step S3, the coefficient K is a function related to the aperture ratio η, and the coefficient K is calculated by the following formula:

[0033] K = 1.2688 × η 2 -0.7316×η+0.7432.

[0034] Preferably, the filter screen is made of synthetic fiber material.

[0035] Preferably, the filter screen is made of PP, PET, or PA.

[0036] Preferably, the filter screen includes a woven filter screen.

[0037] A second aspect of the present invention discloses a computer-readable storage medium storing a computer program, the computer program including program instructions;

[0038] When the program instructions are executed by the processor, the processor performs the method described in any of the preceding statements.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The estimation method proposed in this invention first calculates the aperture ratio of the filter mesh based on its warp and weft densities and wire diameter. Then, it calculates the baseline pressure loss at a reference wind speed based on the aperture ratio. Finally, it calculates the actual pressure loss at the target wind speed based on the aperture ratio and the baseline pressure loss. This method fully utilizes test data from the filter mesh raw materials, allowing for the estimation of pressure loss at different wind speeds for filter meshes of different densities. It avoids the cumbersome process of sample preparation and testing required in filter mesh structure design and optimization, saving technicians significant time and materials, effectively improving the efficiency of structural design and optimization, and promoting rapid product iteration.

[0041] The pressure loss calculated by this method has been verified to have a relative error within ±10%, which meets the product error requirements. Furthermore, the pressure loss of the filter screen can be calculated by combining the fold height and number of folds of the screen plate to obtain the unfolded area of ​​the screen plate, and then the ratio of this area to the surface area of ​​the screen is calculated to obtain the pressure loss of the screen plate filter. Attached Figure Description

[0042] Figure 1 This is a schematic diagram illustrating the relationship between aperture ratio and pressure loss at a reference wind speed. Detailed Implementation

[0043] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0044] Unless otherwise specified, the reagents used in the following description may be commercially available products, the methods used may be known in the art, and any other matters not covered herein may be handled using existing technology.

[0045] Example 1

[0046] The method for calculating the pressure loss of a woven air filter in this invention includes the following steps:

[0047] (1) Select filter screens of different densities, test the relationship between filter screen opening ratio and pressure loss, and derive the fitting formula;

[0048] (2) Calculate the opening ratio of the target filter based on the structural parameters of the target filter;

[0049] (3) Based on the opening ratio of the target filter and the fitting formula obtained above, the pressure loss at different wind speeds is calculated.

[0050] in:

[0051] 1) Formula for calculating the aperture ratio η:

[0052] η=(10-A×D / 100)×(10-B×D / 100) / (10×10)×100%;

[0053] In the formula:

[0054] A represents the number of warp filaments per centimeter in the filter screen;

[0055] B represents the number of filaments per centimeter in the weft direction of the filter screen;

[0056] D is 100 times the diameter of the wires in the filter screen, in millimeters;

[0057] 2) Set a reference wind speed V0, and test the relationship between the filter opening ratio η of different densities and the reference pressure drop P0. This relationship is a logarithmic function, and its general formula is as follows:

[0058] P0 = a × ln(η) + b;

[0059] In the formula:

[0060] a and b are both constants.

[0061] In this scheme, a reference wind speed of 2.5 m / s V0 is preferred. The relationship between the opening ratio η and the reference pressure loss P0 of filter screens with different densities is tested. The test results are shown in Table 1.

[0062] Table 1. Measured data on the aperture ratio and pressure loss of filter screens of different specifications.

[0063]

[0064]

[0065] For example, PP60*56H8-P is a filter specification that indicates: PP is the raw material code (usually PP, PET, PA, etc.); 60 is the warp density code (A): the number of warp filaments per centimeter in the filter; 56 is the weft density code (B): the number of weft filaments per centimeter in the filter; H is the color code; 8 is the filament diameter code: 100 times the diameter of the filaments in the filter (D), in millimeters; P is the weave structure code (usually P represents plain weave, PB represents plain weave, and CS represents honeycomb weave); in addition, there may be a function code between the "PP" item and the "60" item.

[0066] The fitting results from the test results yielded a = -19.39 and b = -2.2359, i.e., P0 = -19.39 × ln(η) - 2.2359. Figure 1 As shown.

[0067] 3) Based on the aforementioned aperture ratio η and the formula obtained from the fitting above, the actual pressure loss P under the target wind speed V can be calculated using the following formula:

[0068] P = K × P0 × V / V0;

[0069] Based on the reference wind speed V0 set at 2.5 m / s in this embodiment, the formula can be expanded as follows:

[0070] P=K×(-19.39×ln(η)-2.2359)×V / 2.5;

[0071] In the above, K is a coefficient, which is a function related to the aperture ratio η. The larger the aperture ratio η is, the larger K is. Its calculation formula is as follows:

[0072] K = 1.2688 × η 2 -0.7316×η+0.7432.

[0073] Application Example 1

[0074] Taking the design of antibacterial filter PPK12*13B14-P as an example, we can see from the specification representation that A=12, B=13, and D=14.

[0075] The pressure loss of this filter screen under different wind speeds was calculated using the method in Example 1, thereby providing pressure loss reference data for the next step of the screen technicians.

[0076] Opening ratio:

[0077] η=(10-A×D / 100)×(10-B×D / 100) / (10×10)×100%=68%;

[0078] At a reference wind speed of 2.5 m / s V0, the filter pressure drop P0 = a × ln(η) + b = -19.39 × ln(68%) - 2.2359 = 5.2 Pa;

[0079] but,

[0080] Calculation of the theoretical pressure loss P of the filter screen at a target wind speed V of 1.0 m / s:

[0081] K = 1.2688 × η 2 -0.7316×η+0.7432=0.83;

[0082] P=K×P0×V / V0=0.83×(-19.39×ln(68%)-2.2359)×1.0 / 2.5=

[0083] 1.73 Pa;

[0084] Calculation of the theoretical pressure loss P of the filter screen at a target wind speed V of 2.0 m / s:

[0085] P=K×P0×V / V0=0.83×(-19.39×ln(68%)-2.2359)×2.0 / 2.5=3.5Pa;

[0086] Further verification was conducted using actual woven PPK12*13B14 filter screens. The actual pressure losses of the filter screens were measured to be 5.0 Pa, 1.6 Pa, and 3.6 Pa at target wind speeds of 2.5 m / s, 1.0 m / s, and 2.0 m / s, respectively.

[0087] Application Example 2

[0088] Taking the design of filter PET15*18H8-P as an example, we can see from the specification representation that A=15, B=18, and D=8.

[0089] The pressure loss of this filter screen under different wind speeds was calculated using the method in Example 1, thereby providing pressure loss reference data for the next step of the screen technicians.

[0090] Opening ratio:

[0091] η=(10-A×D / 100)×(10-B×D / 100) / (10×10)×100%=75%;

[0092] At a reference wind speed of 2.5 m / s V0, the filter pressure drop P0 = a × ln(η) + b = -19.39 × ln(75%) - 2.2359 = 3.3 Pa;

[0093] but,

[0094] Calculation of the theoretical pressure loss P of the filter screen at a target wind speed V of 1.0 m / s:

[0095] K = 1.2688 × η 2 -0.7316×η+0.7432=0.91;

[0096] P=K×P0×V / V0=0.91×(-19.39×ln(75%)-2.2359)×1.0 / 2.5=1.2Pa;

[0097] Calculation of the theoretical pressure loss P of the filter screen at a target wind speed V of 2.0 m / s:

[0098] P=K×P0×V / V0=0.91×(-19.39×ln(75%)-2.2359)×2.0 / 2.5=2.4Pa;

[0099] Further verification was conducted using actual woven PET15*18H8 filter screens. The actual pressure losses of the filter screens were measured to be 3.2 Pa, 1.2 Pa, and 2.5 Pa at target wind speeds of 2.5 m / s, 1.0 m / s, and 2.0 m / s, respectively.

[0100] Comparative Application Example 1

[0101] Taking the design of filter PET15*18H8-PB as an example, we can see from the specification representation that A=15, B=18, D=8. The difference from application example 2 is that the weaving structure is a flat variable structure.

[0102] The pressure loss of this filter screen under different wind speeds was calculated using the method in Example 1, thereby providing pressure loss reference data for the next step of the screen technicians.

[0103] Opening ratio:

[0104] η=(10-A×D / 100)×(10-B×D / 100) / (10×10)×100%=75%;

[0105] At a reference wind speed of 2.5 m / s V0, the theoretical pressure loss of the filter is P0 = a × ln(η) + b = -19.39 × ln(75%) - 2.2359 = 3.3 Pa;

[0106] but,

[0107] Calculation of the theoretical pressure loss P of the filter screen at a target wind speed V of 1.0 m / s:

[0108] K = 1.2688 × η 2 -0.7316×η+0.7432=0.91;

[0109] P=K×P0×V / V0=0.91×(-19.39×ln(75%)-2.2359)×1.0 / 2.5=1.2Pa;

[0110] Calculation of the theoretical pressure loss P of the filter screen at a target wind speed V of 2.0 m / s:

[0111] P=K×P0×V / V0=0.91×(-19.39×ln(75%)-2.2359)×2.0 / 2.5=2.4Pa;

[0112] Further verification was conducted using actual woven filter mesh PET15*18H8-PB. The pressure loss of the filter mesh was measured to be 3.4 Pa, 1.2 Pa, and 2.6 Pa at target wind speeds of 2.5 m / s, 1.0 m / s, and 2.0 m / s, respectively.

[0113] The results of application examples 1 and 2, and the calculation and experimental results of application example 1 are summarized in Table 2 below.

[0114] Table 2. Summary of the calculation and experimental results for Application Examples 1 and 2, and Comparative Application Example 1.

[0115]

[0116]

[0117] As shown in Table 2 above, by comparing the calculated pressure loss data (theoretical value) and experimental measured data (actual value) of the two types of filters, the relative error between the two results is within ±10%, which meets the product error requirements. This verifies and demonstrates that the calculation formula can be used for rapid calculation of pressure loss values ​​of filter screens of different specifications under different wind speeds, and the calculation results have high accuracy. A comparison between Application Example 1 and Application Example 2 shows that the relative error between the theoretical and actual calculated pressure loss values ​​of filter screens with different weave structures is also within ±10%, which conforms to the calculation rules. This indicates that the filter screen weave structure has a negligible impact on the rapid calculation of this method. Furthermore, this demonstrates that although the calculation method proposed in this scheme mainly considers key influencing factors, its calculation results still have extremely high reliability and reference value, and can further ensure the calculation speed, making it very suitable for estimation and on-site calculation.

[0118] The embodiments of this application also provide a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, implement the steps of the method for calculating the pressure loss of a machine-woven air filter provided in the above embodiments of this application.

[0119] The computer-readable storage medium can be a conventional storage unit, such as a hard drive or memory. Alternatively, it can be an external storage device, such as a plug-in hard drive, a Smart MediaCard (SMC), a Secure Digital (SD) card, or a Flash Card.

[0120] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for calculating the pressure loss of a woven air filter, characterized in that, Includes the following steps: S1: Obtain the aperture ratio η: Obtain the number of filaments per centimeter in the warp and weft directions of the filter screen, as well as the diameter of the filaments in the filter screen, and calculate the opening ratio η of the filter screen; S2: Obtain the baseline pressure drop P0: Calculate the reference pressure loss P0 of the filter screen at the reference wind speed V0 based on the opening ratio η; S3: Obtain the actual pressure loss P: Based on the opening ratio η obtained in step S1, the reference pressure loss P0 obtained in step S2, and the set target wind speed V, calculate the actual pressure loss P of the filter screen at the target wind speed V.

2. The method for calculating the pressure loss of a woven air filter according to claim 1, characterized in that, In step S1, the aperture ratio η is calculated using the following formula: η=(10-A×D / 100)×(10-B×D / 100) / (10×10)×100%; In the formula: A represents the number of warp filaments per centimeter in the filter screen; B represents the number of filaments per centimeter in the weft direction of the filter screen; D is 100 times the diameter of the wires in the filter screen, in millimeters.

3. The method for calculating the pressure loss of a woven air filter according to claim 1, characterized in that, In step S2, the reference pressure drop P0 is a logarithmic function related to the aperture ratio η, and the reference pressure drop P0 is calculated by the following formula: P0 = a × ln(η) + b; In the formula: a and b are both constants.

4. The method for calculating the pressure loss of a woven air filter according to claim 1, characterized in that, In step S2, the reference wind speed V0 is 2.5 m / s; The reference pressure loss P0 is calculated using the following formula: P0 = -19.39 × ln(η) - 2.2359.

5. A method for calculating the pressure loss of a woven air filter according to claim 1, characterized in that, In step S3, the actual pressure loss P is calculated using the following formula: P = K × P0 × V / V0; In the formula: K is a coefficient.

6. A method for calculating the pressure loss of a woven air filter according to claim 5, characterized in that, In step S3, the coefficient K is a function related to the aperture ratio η, and the coefficient K is calculated by the following formula: K=1.2688×η 2 -0.7316×η+0.7432。 7. A method for calculating the pressure loss of a woven air filter according to claim 1, characterized in that, The filter screen is made of synthetic fiber materials.

8. A method for calculating the pressure loss of a woven air filter according to claim 7, characterized in that, The filter screen is made of materials including PP, PET, and PA.

9. A method for calculating the pressure loss of a woven air filter according to claim 1, characterized in that, The filter screen includes a woven filter screen.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions; When the program instructions are executed by the processor, the processor performs the method as described in any one of claims 1-9.

Images