Ventilation system energy-saving transformation method based on filtering

Abstract

The invention relates to the technical field of ventilation systems, in particular to a ventilation system energy-saving transformation method based on filtration, which comprises the following steps: S1, in a brand new state of an original filter, measuring a section wind speed V1, filter efficiency e1 and filter pressure loss p1 at the wind speed, and measuring corresponding energy consumption n at running time T; s2, replacing the high-efficiency low-resistance filter, adjusting the wind speed of the operation section of the system to V1, measuring the efficiency E1 and the filtering pressure loss P1 of the filter at the wind speed, and measuring the corresponding energy consumption N of the operation time T; and S3, implementing energy efficiency evaluation. In the early stage of replacing the high-efficiency low-resistance filter, the initial resistance is lower, the needed fan work is reduced, under the condition of the same ventilation quantity, the fan work is reduced, the energy consumption is lower, in the middle and later stages of replacing the high-efficiency low-resistance filter, the final resistance is lower than that of an original filter, the average resistance is lower, and the needed fan work is reduced in the whole life cycle stage. Therefore, energy conservation is realized.

Description

Technical Field

[0001] This invention relates to the field of ventilation system technology, and more specifically to a method for energy-saving retrofitting of ventilation systems based on filtration. Background Technology

[0002] Ventilation systems are a building environment control technology that uses methods such as air exchange and dilution or ventilation and exhaust to control the spread and harm of air pollutants and ensure the quality of indoor and outdoor air environments.

[0003] Filters are a component of ventilation systems and an important means of controlling air pollutants. Filters can be classified according to their performance levels as: coarse, medium, high-medium, sub-high efficiency, and high efficiency filters. Filters are installed in series from low to high efficiency according to the airflow direction of the ventilation system.

[0004] The existing energy-saving retrofit of ventilation systems mainly involves adding a frequency converter to the power supply wiring front end of the AC motor to achieve load adjustment on demand. The internal functional sections or components are not adjusted and traditional components are used. That is, the purpose of load adjustment is achieved by adding a frequency converter without changing any functional sections. Since the main component that consumes the static pressure of the fan in the ventilation system is the filter, and traditional filters have the problem of high initial resistance and final resistance, the energy-saving retrofit scheme using traditional technology does not optimize the filter, a large load unit, which will inevitably lead to limited energy-saving efficiency and small energy-saving potential. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art by proposing a method for energy-saving retrofitting of ventilation systems based on filtration.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for energy-saving retrofitting of a filtration-based ventilation system includes the following steps:

[0008] S1. Under the original filter's brand-new condition, measure the cross-sectional wind speed V1, the filter efficiency e1 and filter pressure loss p1 at that wind speed, and measure the corresponding energy consumption n over the operating time T.

[0009] S2. Replace the high-efficiency low-resistance filter and adjust the system operating section wind speed to V1. Measure the filter efficiency E1 and filtration pressure loss P1 at this wind speed, and measure the corresponding energy consumption N for the operating time T.

[0010] S3. Implement energy efficiency assessment;

[0011] The filter efficiency is the ratio of the difference in the concentration of a specific diameter particle in the airflow on the upwind side and the airflow on the downwind side of the filter to the corresponding particle concentration in the airflow on the upwind side.

[0012] The filter pressure loss is measured by measuring the static pressure loss upstream and downstream of the filter.

[0013] Preferably, in step S1, after the original filter has been running for T, the cross-sectional wind speed V2 and the filter efficiency e2 and pressure drop p2 at that wind speed are measured.

[0014] In step S2, for the high-efficiency low-resistance filter operating time T, the ventilation system load is adjusted based on the speed reduction strategy to make the cross-sectional wind speed V1 to V2, and the filter efficiency E2, pressure loss P2 and energy consumption N are measured at the cross-sectional wind speed V2.

[0015] Preferably, the source of the particles with the specific diameter can be one of the following methods:

[0016] 1) The particulate matter source is natural dust, that is, the concentration of particles in the upstream of the actual use environment is directly measured;

[0017] 2) Add a dust generator with a specific particle size upstream to increase the concentration of this particulate matter;

[0018] The diameter of the specific diameter particles is one of the following:

[0019] 1) Particles with a diameter ≥ 2.0 μm;

[0020] 2) Particles with a diameter ≤ 2.5 μm;

[0021] 3) Particles with a diameter ≤ 0.3 μm;

[0022] 4) Particles with a diameter ≥ 0.3 μm;

[0023] 5) Particles with a diameter of 0.4 μm;

[0024] 6) Particles with a diameter ≥ 0.5 μm.

[0025] Preferably, the original filter uses a series of multi-stage filters, and each stage of the filter needs to be measured independently.

[0026] Preferably, the operating time T ≥ 0.5 * the nominal lifespan of the filter.

[0027] Preferably, the cross-sectional wind speed measurement is performed using one of the following methods:

[0028] 1) Directly measure the wind speed at the inlet or outlet section of the ventilation system;

[0029] 2) Directly measure the wind speed at any cross-section of a stable airflow zone inside the ventilation system;

[0030] 3) Measure the air volume and cross-sectional area of ​​any section of the ventilation system, and then calculate the wind speed.

[0031] Preferably, the high-efficiency low-resistance filter is a filter with the same cross-section and wind speed V1, where the measured efficiency E1 of the replacement filter is greater than or equal to the efficiency e1 of the original filter, the pressure loss P1 of the replacement filter is less than or equal to the pressure loss p1*s of the original filter, and s ≤ 0.75.

[0032] Preferably, the high-efficiency low-resistance filter is a filter with the same cross-sectional wind speed V2 after operation time T, where the measured efficiency E2 of the replacement filter is greater than or equal to the efficiency e1 and e2 of the original filter, and the pressure loss P2 of the replacement filter is less than or equal to the pressure loss p2*s of the original filter, and s ≤ 0.5.

[0033] Preferably, the speed reduction strategy adopts one of the following methods:

[0034] 1) Average reduction method, reducing the speed from V1 to V2 in an average of hours, days or weeks;

[0035] 2) End-point speed reduction method: The initial operating wind speed is V1, and after operating time T, the wind speed is directly adjusted to V2.

[0036] Preferably, the energy efficiency assessment includes filter performance stability assessment, graded energy saving estimation, and actual energy saving assessment;

[0037] The filter performance stability assessment includes the following steps:

[0038] S4. Draw straight lines based on the coordinate points (0, e1), (T, e2) and (0, E1), (T, E2), and calculate the slope K for each line.

[0039] S5. Determine the stability of the filter performance;

[0040] The graded energy-saving estimation includes the following steps:

[0041] S6. Classify ventilation systems into coarse, medium, high-efficiency, sub-high efficiency, and high efficiency levels;

[0042] S7. Calculate the energy efficiency ratio C of each initial resistance level. 初 =1-P1 / p1*100%, the final resistance energy-saving efficiency ratio C 试终 =1-P2 / p2*100% and the final energy of the experiment

[0043] The actual energy-saving assessment includes the following steps:

[0044] S8, Actual energy saving w = nN;

[0045] S9. Comparative analysis of the sum of actual energy saving w and experimental final energy saving ω.

[0046] Compared with existing technologies, the advantages of this invention are:

[0047] 1. In the initial stage of replacing with a high-efficiency, low-resistance filter, the initial resistance is lower, which requires less work from the fan. Under the same ventilation volume, the fan's work is reduced, resulting in lower energy consumption.

[0048] 2: In the later stages of replacing with high-efficiency, low-resistance filters, the final resistance is lower than that of the original filters, the average resistance is even lower, and the work required by the fan throughout the entire life cycle is reduced, thereby achieving energy saving.

[0049] 3. Add stability assessment to avoid adverse effects caused by reduced efficiency while saving energy. Attached Figure Description

[0050] Figure 1 This is a schematic diagram illustrating the steps of a filtration-based energy-saving retrofit method for a ventilation system proposed in this invention.

[0051] Figure 2 This is a linear graph of the slope K in Example 2. Detailed Implementation

[0052] The technical solutions of 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Reference Figure 1 A method for energy-saving retrofitting of a filtration-based ventilation system includes the following steps:

[0054] S1. Under the original filter's brand-new condition, measure the cross-sectional wind speed V1, the filter efficiency e1 and filter pressure loss p1 at that wind speed, and measure the corresponding energy consumption n over the operating time T.

[0055] S2. Replace the high-efficiency low-resistance filter and adjust the system operating section wind speed to V1. Measure the filter efficiency E1 and filtration pressure loss P1 at this wind speed, and measure the corresponding energy consumption N for the operating time T.

[0056] S3. Implement energy efficiency assessment;

[0057] Filter efficiency is the ratio of the difference in the concentration of a specific diameter particle in the airflow on the upwind side and the airflow on the downwind side of the filter to the corresponding particle concentration in the upwind side airflow.

[0058] Filter pressure loss is measured by measuring the static pressure loss upstream and downstream of the filter.

[0059] In step S1, after the original filter has been running for T, the cross-sectional wind speed V2 and the filter efficiency e2 and pressure loss p2 at that wind speed are measured.

[0060] In step S2, for the high-efficiency low-resistance filter operating time T, the ventilation system load is adjusted based on the speed reduction strategy to make the cross-sectional wind speed V1 to V2, and the filter efficiency E2, pressure loss P2 and energy consumption N are measured at the cross-sectional wind speed V2.

[0061] Particulate matter of a specific diameter can be sourced in one of the following ways:

[0062] 1) The particulate matter source is natural dust, that is, the concentration of particles in the upstream of the actual use environment is directly measured;

[0063] 2) Add a dust generator with a specific particle size upstream to increase the concentration of this particulate matter;

[0064] The diameter of particles with a specific diameter can be one of the following:

[0065] 2) Particles with a diameter ≥ 2.0 μm;

[0066] 2) Particles with a diameter ≤ 2.5 μm;

[0067] 3) Particles with a diameter ≤ 0.3 μm;

[0068] 4) Particles with a diameter ≥ 0.3 μm;

[0069] 5) Particles with a diameter of 0.4 μm;

[0070] 6) Particles with a diameter ≥ 0.5 μm.

[0071] The original filter used multiple filters connected in series, requiring independent measurement of each filter stage.

[0072] Operating time T ≥ 0.5 * nominal filter life.

[0073] Cross-sectional wind speed measurement can be performed using one of the following methods:

[0074] 1) Directly measure the wind speed at the inlet or outlet section of the ventilation system;

[0075] 2) Directly measure the wind speed at any cross-section of a stable airflow zone inside the ventilation system;

[0076] 3) Measure the air volume and cross-sectional area of ​​any section of the ventilation system, and then calculate the wind speed.

[0077] For a high-efficiency, low-resistance filter with the same cross-section and wind speed V1, the measured efficiency E1 of the replacement filter is greater than or equal to the efficiency e1 of the original filter, and the pressure loss P1 of the replacement filter is less than or equal to the pressure loss p1*s of the original filter, where s ≤ 0.75.

[0078] The high-efficiency, low-resistance filter is defined as a filter with the same cross-section and wind speed V2 after an operating time T, where the measured efficiency E2 of the replacement filter is greater than or equal to the efficiency e1 and e2 of the original filter, and the pressure loss P2 of the replacement filter is less than or equal to the pressure loss p2*s of the original filter, and s ≤ 0.5.

[0079] The deceleration strategy adopts one of the following methods:

[0080] 1) Average reduction method, reducing the speed from V1 to V2 in an average of hours, days or weeks;

[0081] 2) End-point speed reduction method: The initial operating wind speed is V1, and after operating time T, the wind speed is directly adjusted to V2.

[0082] Energy efficiency assessment includes filter performance stability assessment, graded energy saving estimation, and actual energy saving assessment;

[0083] Filter performance stability assessment includes the following steps:

[0084] S4. Draw straight lines based on the coordinate points (0, e1), (T, e2) and (0, E1), (T, E2), and calculate the slope K for each line.

[0085] S5. Determine the stability of the filter performance, as shown in the table below;

[0086] K K≥0 K＜0 stability Stablize Unstable

[0087] Graded energy saving estimation includes the following steps:

[0088] S6. Classify ventilation systems into coarse, medium, high-efficiency, sub-high efficiency, and high efficiency levels;

[0089] S7. Calculate the energy efficiency ratio C of each initial resistance level. 初 =1-P1 / p1*100%, the final resistance energy-saving efficiency ratio C 试终 =1-P2 / p2*100% and the final energy of the experiment Where q is the air volume (unit: m³) 3 / s), (Unit: Pa), t = T (unit: h), η is the conversion efficiency with a value of 0.5;

[0090] Actual energy efficiency assessment includes the following steps:

[0091] S8, Actual energy saving w = nN;

[0092] S9. Comparative analysis of the sum of actual energy saving w and experimental final energy saving ω.

[0093] The energy-saving retrofit of the ventilation system of the present invention will be described below through specific embodiments.

[0094] Example 1: Energy-saving retrofit of a ventilation system with a three-stage filtration system

[0095] The first step is to measure the raw filter data.

[0096] The original filter consisted of three filters connected in series, with nominal efficiencies of: coarse (G4), medium-high efficiency (F8), and high efficiency (H13), and a rated air velocity of 40,000 m / s. 3 / h, an upstream particle size dust generator is added, and the cross-sectional wind speed measurement position is 350mm after the second stage filter of the ventilation system, with a cross-sectional area of ​​4.45m². 2 The data for each stage of the filter were measured independently, as shown in the table below:

[0097]

[0098] The operating time is T = 24 hours, corresponding to an energy consumption of n = 457.44 kWh;

[0099] The second step is to replace the high-efficiency, low-resistance filter and measure the corresponding data.

[0100] All three stages were replaced with high-efficiency, low-resistance filters, and the same measurement method as in the first step was used. The measurement data is shown in the table below:

[0101]

[0102] The operating time is T = 24 hours, and the corresponding energy consumption is N = 330.45 kWh.

[0103] For the same cross-sectional wind speed, the above high-efficiency, low-resistance filters are as follows:

[0104] For the first stage filter, the measured efficiency of the replacement filter is greater than that of the original filter, and the pressure loss of the replacement filter is 0.310 times that of the original filter.

[0105] The second stage filter has a measured efficiency greater than that of the original filter, and the pressure loss of the replacement filter is 0.411 times that of the original filter.

[0106] The third-stage filter has a measured efficiency greater than that of the original filter, and the pressure loss of the replacement filter is 0.552 times that of the original filter.

[0107] The third step is to conduct an energy efficiency assessment.

[0108] I. Graded Energy Saving Estimation

[0109] 1) Differentiate the ventilation system into three levels: the first level is coarse efficiency, the second level is medium-high efficiency, and the third level is high efficiency;

[0110] 2) Calculate the energy-saving efficiency ratio of the initial resistance at each stage and the final energy saving ω at the end of the test;

[0111] Coarse initial resistance energy efficiency ratio C初1 =1-P1 / p1*100%=1-45 / 145=68.97%;

[0112] High-efficiency initial resistance energy-saving efficiency ratio C 初2 =1 - 78 / 190 = 58.95%;

[0113] High initial resistance energy saving efficiency ratio C 初3 =1 - 196 / 355 = 44.79%;

[0114] II. Actual Energy Saving Assessment

[0115] The actual energy saving is w = nN = 457.44 - 330.45 = 126.99 kWh.

[0116] Example 2: Energy-saving retrofit of a ventilation system based on initial filtration resistance + test final resistance (coarse filter G4, medium-high efficiency F7)

[0117] The first step is to measure the raw filter data.

[0118] The original filter consisted of two filters connected in series, with nominal efficiencies of G4 (coarse) and F7 (medium-high efficiency). The user provided nominal lifespans of 3 months and 6 months respectively, and a rated air velocity of 76,000 m / s. 3 / h, upstream natural dust sampling was used, and the cross-sectional wind speed measurement location was the cross-section of the ventilation system's air supply duct, with a cross-sectional area of ​​2.82m². 2 The data for each stage of the filter were measured independently, as shown in the table below:

[0119]

[0120] Running time T = 90 calendar days, measure again using the same method as above:

[0121]

[0122] The corresponding energy consumption is n = 55317.6 kWh.

[0123] The second step is to replace the high-efficiency, low-resistance filter and measure the corresponding data.

[0124] Both sections were replaced with high-efficiency, low-resistance filters, and the same measurement method as in the first step was used. The measurement data is shown in the table below:

[0125]

[0126] The operating time T = 90 calendar days, and the endpoint speed reduction method is used, that is, the wind speed is directly adjusted to 5.9 m / s during the 90-day operating time, and the same method as in the first step is used to measure again:

[0127]

[0128] The operating time T = 90 (days) corresponds to an energy consumption of N = 35143.2 kWh.

[0129] The above high-efficiency, low-resistance filter:

[0130] Under the initial conditions of wind speed V1 = 7.1 m / s at the same cross-section:

[0131] The first stage filter: the measured efficiency of the replacement filter is equal to the efficiency of the original filter, and the pressure loss of the replacement filter is 0.333 times that of the original filter.

[0132] The second stage filter has a measured efficiency greater than that of the original filter, and the pressure loss of the replacement filter is 0.418 times that of the original filter.

[0133] After an operating time of T = 90 days, under the same cross-section wind speed V2 = 5.9 m / s:

[0134] The first stage filter, the measured efficiency of the replacement filter (67%) is greater than the efficiency of the original filter (55%) (initial efficiency), the pressure loss of the replacement filter is 0.304 times that of the original filter after a period of time T;

[0135] The second stage filter, the measured efficiency of the replacement filter (89%) is greater than that of the original filter (73%) (initial efficiency), and the pressure loss of the replacement filter is 0.361 times that of the original filter after a period of time T.

[0136] The third step is to conduct an energy efficiency assessment:

[0137] I. Filter Performance Stability Assessment

[0138] 1) Draw a straight line based on the coordinates (0, 55%), (90, 87%), (0, 73%), (90, 32%) and (0, 55%), (90, 67%), (0, 75%), (90, 89%) as shown below. Figure 2 As shown, calculate the slope K respectively;

[0139] 2) Determine the stability of the filter performance, as shown in the table below:

[0140] Filter K value stability Original Filter - First Segment K＞0 Stablize Original Filter - Second Stage K＜0 Unstable Replace the filter - first section K＞0 Stablize Replace the filter - second section K＞0 Stablize

[0141] II. Graded Energy Saving Estimation

[0142] 1) Differentiate the ventilation system into different levels: the first level is coarse efficiency, and the second level is medium efficiency.

[0143] 2) Calculate the energy-saving efficiency ratio of the initial resistance at each stage, the energy-saving efficiency ratio of the final resistance at the end of the test, and the energy saved at the end of the test ω;

[0144] Coarse initial resistance energy efficiency ratio C初1 =1-P1 / p1*100%=1-46 / 138*100%=66.67%;

[0145] Coarse-effect test final resistance energy efficiency ratio C 试终1 =1-P2 / p2*100%=1-86 / 282*100%=69.50%;

[0146] Coarse-effect test final energy saving

[0147] High-efficiency initial resistance energy-saving efficiency ratio C 初2 =1-69 / 165*100%=58.18%;

[0148] High-efficiency test final resistance energy saving efficiency ratio C 试终2 =1 - 91 / 252 * 100% = 63.89%;

[0149] High-efficiency test final energy saving

[0150] III. Actual Energy Saving Assessment

[0151] Actual energy saving w = nN = 55317.6 - 35143.2 = 20174.4 kWh

[0152] The energy saving in the experiment was ω=ω1+ω2=2=20638.8kwh, with a deviation of <±5%, indicating that the theoretical calculation and actual measurement are reasonable.

[0153] In the initial stage of replacing the filter with a high-efficiency, low-resistance filter, the initial resistance is lower, the fan work required is reduced, and the fan work is reduced under the same ventilation volume, resulting in lower energy consumption.

[0154] Furthermore, in the later stages of replacing the filter with a high-efficiency, low-resistance filter, the final resistance is lower than that of the original filter, the average resistance is even lower, and the work required by the fan throughout the entire life cycle is reduced, thereby achieving energy saving.

[0155] In addition, a stability assessment is added to avoid the adverse effects of reduced efficiency while saving energy.

[0156] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for energy-saving retrofitting of a filtration-based ventilation system, characterized in that, Includes the following steps: S1. Under the original filter's brand-new condition, measure the cross-sectional wind speed V1, the filter efficiency e1 and filter pressure loss p1 at that wind speed, and measure the corresponding energy consumption n over the operating time T. S2. Replace the high-efficiency low-resistance filter and adjust the system operating section wind speed to V1. Measure the filter efficiency E1 and filtration pressure loss P1 at this wind speed, and measure the corresponding energy consumption N for the operating time T. S3. Implement energy efficiency assessment; The filter efficiency is the ratio of the difference in the concentration of a specific diameter particle in the airflow on the upwind side and the airflow on the downwind side of the filter to the corresponding particle concentration in the airflow on the upwind side. The filter pressure loss is measured by measuring the static pressure loss upstream and downstream of the filter.

2. The energy-saving retrofit method for a filtration-based ventilation system according to claim 1, characterized in that, In step S1, after the original filter has been running for T, the cross-sectional wind speed V2 and the filter efficiency e2 and pressure loss p2 at that wind speed are measured. In step S2, for the high-efficiency low-resistance filter operating time T, the ventilation system load is adjusted based on the speed reduction strategy to make the cross-sectional wind speed V1 to V2, and the filter efficiency E2, pressure loss P2 and energy consumption N are measured at the cross-sectional wind speed V2.

3. The energy-saving retrofit method for a filtration-based ventilation system according to claim 1, characterized in that, The specific diameter particles can be sourced in one of the following ways: 1) The particulate matter source is natural dust, that is, the concentration of particles in the upstream of the actual use environment is directly measured; 2) Add a dust generator with a specific particle size upstream to increase the concentration of this particulate matter; The diameter of the specific diameter particles is one of the following: 1) Particles with a diameter ≥ 2.0 μm; 2) Particles with a diameter ≤ 2.5 μm; 3) Particles with a diameter ≤ 0.3 μm; 4) Particles with a diameter ≥ 0.3 μm; 5) Particles with a diameter of 0.4 μm; 6) Particles with a diameter ≥ 0.5 μm.

4. The energy-saving retrofit method for a filtration-based ventilation system according to claim 1, characterized in that, The original filter uses multiple filters connected in series, and each filter needs to be measured independently.

5. The energy-saving retrofit method for a filtration-based ventilation system according to claim 1, characterized in that, The operating time T ≥ 0.5 * the nominal lifespan of the filter.

6. The energy-saving retrofit method for a filtration-based ventilation system according to claim 1, characterized in that, The cross-sectional wind speed measurement is performed using one of the following methods: 1) Directly measure the wind speed at the inlet or outlet section of the ventilation system; 2) Directly measure the wind speed at any cross-section of a stable airflow zone inside the ventilation system; 3) Measure the air volume and cross-sectional area of ​​any section of the ventilation system, and then calculate the wind speed.

7. The energy-saving retrofit method for a filtration-based ventilation system according to claim 1, characterized in that, The high-efficiency, low-resistance filter is a filter with the same cross-section and wind speed V1, where the measured efficiency E1 of the replacement filter is greater than or equal to the efficiency e1 of the original filter, the pressure loss P1 of the replacement filter is less than or equal to the pressure loss p1*s of the original filter, and s ≤ 0.

75.

8. The energy-saving retrofit method for a filtration-based ventilation system according to claim 2, characterized in that, The high-efficiency, low-resistance filter is a filter with the same cross-section wind speed V2 after operation time T, whose measured efficiency E2 is greater than or equal to the original filter efficiency e1 and e2, and whose pressure drop P2 is less than or equal to the original filter pressure drop p2*s, and s ≤ 0.

5.

9. The energy-saving retrofit method for a filtration-based ventilation system according to claim 2, characterized in that, The speed reduction strategy adopts one of the following methods: 1) Average reduction method, reducing the speed from V1 to V2 in an average of hours, days or weeks; 2) End-point speed reduction method: The initial operating wind speed is V1, and after operating time T, the wind speed is directly adjusted to V2.

10. The energy-saving retrofit method for a filtration-based ventilation system according to claim 1, characterized in that, The energy efficiency assessment includes filter performance stability assessment, graded energy saving estimation, and actual energy saving assessment. The filter performance stability assessment includes the following steps: S4. Draw straight lines based on the coordinate points (0, e1), (T, e2) and (0, E1), (T, E2), and calculate the slope K for each line. S5. Determine the stability of the filter performance; The graded energy-saving estimation includes the following steps: S6. Classify ventilation systems into coarse, medium, high-efficiency, sub-high efficiency, and high efficiency levels; S7. Calculate the energy efficiency ratio C of each initial resistance level. 初 =1-P1 / p1*100%, the final resistance energy-saving efficiency ratio C 试终 =1-P2 / p2*100% and the final energy of the experiment The actual energy-saving assessment includes the following steps: S8, Actual energy saving w = nN; S9. Comparative analysis of the sum of actual energy saving w and experimental final energy saving ω.

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