Method and system for monitoring air volume of centrifugal fan

Abstract

The application relates to the technical field of air conditioning treatment, in particular to a centrifugal fan air volume monitoring method and system, which comprises the following steps: analyzing the difference between real-time monitoring data and all belt tension data obtained through experimental monitoring data, so as to calculate the deviation degree of the air volume value measured based on the static pressure method of the real-time monitoring data under different frequencies, and obtain a real-time air volume value; based on the fluctuation degree of the wind speed data in all wind speed sensors, and by using the chaotic distribution of the fluctuation degree calculated by all wind speed sensors, and the average distribution of the fluctuation degree calculated at all collection moments, the reliability of the real-time measurement of the air volume based on the wind speed method is obtained, and a real-time air volume is determined; the air volume values measured by the static pressure method and the wind speed method are comprehensively determined, and the deviation degree and the reliability of the respective measurement methods are determined, so as to determine the final air volume of the centrifugal fan. The application aims to comprehensively consider the results of the static pressure method and the wind speed method, and improve the overall accuracy and reliability of the air volume measurement.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, specifically to a method and system for monitoring the air volume of a centrifugal fan. Background Technology

[0002] Centrifugal fans are widely used as key equipment in modern industrial production and commercial operations, serving as crucial components in ventilation, air exchange, and dust removal systems. However, monitoring the airflow of centrifugal fans currently faces numerous challenges. Traditional methods, such as the Pitot tube method, orifice plate flowmeter method, anemometer method, and Pitot tube-micromanometer combination method, have many shortcomings and cannot meet the high precision, real-time performance, and long-term stability requirements of industrial production. Therefore, an advanced airflow monitoring method is urgently needed to address these issues and provide strong support for the efficient operation of centrifugal fans and the optimization of system performance.

[0003] In practical applications, centrifugal fans operate under complex and diverse conditions, and their airflow is affected by various factors, such as fan speed, blade angle, duct resistance, ambient temperature, and humidity. Traditional monitoring methods exhibit significant limitations when dealing with these complex conditions. For example, the Pitot tube method is easily affected by airflow disturbances within the duct, leading to inaccurate measurement results; the orifice plate flowmeter method has high installation and maintenance costs and increases duct resistance; the anemometer method's measurement accuracy is easily affected by environmental factors, requiring frequent calibration and maintenance; and the static pressure method for measuring belt-driven centrifugal fans is affected by belt wear, resulting in low measurement accuracy.

[0004] The shortcomings of these traditional methods not only affect the accuracy of air volume monitoring, but also limit the real-time monitoring and timely adjustment of the centrifugal fan's operating status, making it difficult to meet the requirements of modern industrial production for efficient, precise, and intelligent equipment management. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a method and system for monitoring the airflow of a centrifugal fan, the specific technical solution of which is as follows:

[0006] In a first aspect, one embodiment of this application provides a method for monitoring the air volume of a centrifugal fan, the method comprising the following steps:

[0007] Obtain the airflow-static pressure curves of the fan at different frequencies; obtain the airflow measurement deviation values ​​using the static pressure method from experiments on the belt under different wear levels; analyze the differences between all belt tension data obtained from real-time monitoring data and experimental monitoring data, and screen out multiple experimental monitoring data with belt conditions similar to those in the real-time monitoring data at different frequencies to calculate the degree of deviation of the airflow values ​​measured by the static pressure method in the real-time monitoring data at different frequencies; and obtain the airflow value in the airflow-static pressure curve of the real-time monitoring data measured by the static pressure method at the corresponding frequency.

[0008] Based on the fluctuation of wind speed data from all wind speed sensors, wind speed stability is determined; the uniformity of distribution is determined by the chaotic distribution of the fluctuation calculated from all wind speed sensors and the average distribution of the fluctuation calculated at all acquisition times; the wind speed stability index and the uniformity of distribution are positively fused to obtain the reliability of real-time air volume measurement based on the wind speed method; the air volume at the outlet measured in real-time based on the wind speed method is determined by using the average wind speed at the current moment and the cross-sectional area corresponding to the measurement position of the wind speed sensor.

[0009] The final air volume of the centrifugal fan is determined by combining the real-time air volume values ​​measured by the combined static pressure method and the wind speed method, as well as the deviation and reliability of each measurement method.

[0010] Preferably, the method for selecting multiple experimental monitoring data points that are similar to the belt condition data of the fan at different frequencies and real-time monitoring data is as follows:

[0011] Based on the differences between real-time monitoring data and any experimental monitoring data obtained at the same fan frequency, the similarity of belt wear between the real-time monitoring data and the any experimental monitoring data is determined.

[0012] Experimental monitoring data with belt wear similarity greater than a preset similarity threshold are used as experimental monitoring data with belt condition similar to real-time monitoring data.

[0013] Preferably, the method for determining the similarity of belt wear is as follows:

[0014] Calculate the normalized value of the sum of the differences between real-time monitoring data and any experimental monitoring data obtained at the same fan frequency for all belt tension data;

[0015] The difference between the value 1 and the normalized value is used as the similarity of belt wear between the real-time monitoring data and any experimental monitoring data at the same fan frequency.

[0016] Preferably, the method for calculating the degree of deviation is as follows:

[0017] The normalized value of the average air volume measurement deviation value corresponding to all experimental monitoring data with belt conditions similar to the real-time monitoring data at the same frequency is used as the degree of deviation of the air volume value measured by the static pressure method based on the real-time monitoring data at the same frequency.

[0018] Preferably, the method for determining wind speed stability is as follows: calculate the variance of all wind speed data of each wind speed sensor during the collection period, take the reciprocal of the mean of the variance values ​​calculated by all wind speed sensors, and then normalize them to obtain the wind speed stability.

[0019] Preferably, the method for determining the uniformity of distribution is as follows:

[0020] The variance of the variance values ​​calculated by all wind speed sensors is used as the first wind speed uniformity index.

[0021] The wind speed variance of all wind speed sensors at each acquisition time is normalized and used as the wind speed uniformity at that time. The average value of the wind speed uniformity at all times is used as the second wind speed uniformity index.

[0022] The average value of the first and second wind speed uniformity indices is taken as the distribution uniformity.

[0023] Preferably, the reliability is positively correlated with the wind speed stability and the distribution uniformity, respectively.

[0024] Preferably, the method for determining the outlet air volume based on real-time measurement using the wind speed method is as follows:

[0025] The average wind speed values ​​collected from all wind speed sensors at the current moment are multiplied by the cross-sectional area corresponding to the measurement location of the wind speed sensor to obtain the air volume at the outlet based on the wind speed method in real time.

[0026] Preferably, the method for determining the air volume of the final centrifugal fan is as follows:

[0027]

[0028] In the formula, Pw represents the final air volume of the centrifugal fan obtained by combining the static pressure method and the wind speed method, PL represents the deviation of the real-time monitoring data based on the air volume value measured by the static pressure method, Kf represents the reliability of the air volume measurement based on the wind speed method, Fc represents the air volume value measured in real time based on the static pressure method, and Fv represents the outlet air volume measured in real time based on the wind speed method.

[0029] Secondly, another embodiment of this application provides an airflow monitoring system for a centrifugal fan, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the airflow monitoring method for a centrifugal fan described in any of the above claims.

[0030] This application has at least the following beneficial effects:

[0031] This application assesses wear by monitoring belt tension changes and repeatedly analyzes the impact of different wear levels on the measurement deviation of the static pressure method. This allows for early understanding of the influence of belt wear on measurement results, enabling corrections during actual monitoring and improving measurement reliability. Based on the similarity calculation between the collected tension data sequence and experimental data, the deviation of the real-time airflow value measured by the static pressure method is obtained, providing a basis for accurate subsequent airflow value acquisition and effectively addressing measurement deviations caused by belt wear. A first uniformity index is obtained by calculating the variance of different wind speed variances, and a second uniformity index is obtained by calculating and normalizing the variance of wind speed differences among sensors at the same time. The average of these two indices yields the overall distribution uniformity index, comprehensively reflecting the uniformity of airflow at the centrifugal fan outlet and providing a crucial basis for accurately assessing the reliability of the wind speed method. Finally, by combining the results of the static pressure method and the wind speed method, considering their respective influencing factors, the advantages of both methods are fully utilized, compensating for the shortcomings of a single method, and improving the overall accuracy and reliability of airflow measurement. Attached Figure Description

[0032] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart illustrating a method for monitoring the airflow of a centrifugal fan, provided as an embodiment of this application. Detailed Implementation

[0034] Example 1

[0035] One embodiment of this application provides a method for monitoring the air volume of a centrifugal fan, which can be found in the following reference. Figure 1 The method includes the following steps:

[0036] step Data collection.

[0037] This application combines the static pressure method and the anemometer method to obtain measurement results based on both methods. By integrating multiple airflow detection methods, it accurately obtains the airflow measurement results of the centrifugal fan. Therefore, the data acquisition design and related measurement parameters of this application are as follows:

[0038] Among them, the hot-wire anemometer directly measures the wind speed at a certain cross-sectional distribution point, and the air volume is calculated from the average wind speed and cross-sectional area. The static pressure difference method uses the relationship between the static pressure difference at the fan inlet section and the air volume; the fan air volume can be calculated by measuring the static pressure difference.

[0039] Therefore, the anemometer is first placed at the outlet of the centrifugal fan to measure the wind speed. The cross-sectional area S of the outlet corresponding to the installation position of the anemometer is then obtained.

[0040] The static pressure difference between the inlet and outlet of the centrifugal fan is measured using a differential pressure sensor. Since this application uses a belt-driven centrifugal fan, it is necessary to analyze the impact of belt wear on the measurement results; therefore, a belt tension meter is installed to collect belt tension data.

[0041] Therefore, during monitoring, a monitoring data vector H={U, E, Y} is obtained at each monitoring moment, where U={V1,V2,V3,…,Vn}, V1, V2, V3, and Vn represent the wind speed values ​​obtained by the 1st, 2nd, 3rd, and nth wind speed sensors, respectively. In this embodiment, n=8, meaning that 8 wind speed sensors are evenly placed at the same cross-section at the air outlet to collect wind speed data; E represents the static pressure difference; Y={Y1,Y2,Y3,…Ym}, where Y1, Y2, Y3, and Ym represent the belt tension data obtained by the 1st, 2nd, 3rd, and mth belt tension measuring instruments on the belt of the belt-driven centrifugal fan, respectively. In this embodiment, m=3, meaning that three belt tension measuring instruments are evenly placed on the conveyor belt to collect belt tension data. In this embodiment, the above data is collected once per second, and the collection duration is set by the implementer according to the actual situation. In this embodiment, it is set to the data from the previous hour.

[0042] step Real-time air volume measurement based on static pressure method.

[0043] The main logical steps involve analyzing the impact of belt wear on the static pressure method for measuring air volume through multiple experimental data. This is detailed below:

[0044] 1. Obtain the air volume-static pressure curves of the fan at different frequencies.

[0045] For static pressure measurement, the value is mostly obtained based on the fan characteristic curve. That is, the static pressure value is obtained through a pressure sensor, and the corresponding air volume can be obtained by looking up the fan characteristic curve. Therefore, when measuring air volume based on the static pressure method, it is necessary to obtain the fan characteristic curve of the corresponding centrifugal fan in advance.

[0046] In the fan airflow-static pressure curve, the horizontal axis represents airflow, and the vertical axis represents static pressure. Each curve represents the relationship between static pressure and airflow at a given fan frequency. This curve can be obtained directly from the manufacturer or experimentally using the controlled variable method. By adjusting the fan speed or outlet valve opening, the operating conditions of the fan are changed, and the airflow and static pressure values ​​under different conditions are measured. Airflow can be obtained using methods such as the anemometer method or the Pitot tube method. For example, to obtain the relationship between static pressure and airflow at a fan frequency of 20Hz, other parameters need to be kept constant while changing the airflow, and the static pressure value is obtained from the sensor. By continuously changing the fan speed or outlet valve opening to change the airflow, different static pressure values ​​can be obtained, thus yielding the characteristic curve of static pressure and airflow at a fan frequency of 20Hz.

[0047] 2. Obtain the air volume measurement deviation value using the static pressure method obtained from experiments on belts under different wear levels.

[0048] Centrifugal fans use belt drive, where the motor's rotation transmits energy to the fan impeller via the belt, driving the fan's rotation. Prolonged use inevitably leads to localized belt wear, causing slippage. Slippage reduces the energy transferred from the motor's drive wheel to the fan impeller; in other words, at the same frequency, the impeller rotates at a lower speed, resulting in less airflow and greater energy loss.

[0049] Therefore, a belt tension meter needs to be installed below the belt or at the pulley to monitor changes in belt tension in real time and determine the degree of belt wear based on these changes. When the belt wears, its tension will decrease accordingly, and the extent of belt wear can be detected promptly by monitoring these tension changes.

[0050] The experiment was repeated using the above method to analyze the impact of different belt wear degrees on the reliability of static pressure-based measurements. The belt wear degree can be simulated by adjusting the belt tension. The fan speed or outlet valve opening was changed multiple times under the same wear degree to change the fan air volume. The difference between the air volume value measured by the static pressure method and the air volume value obtained by the wind speed method or other methods (in this embodiment, the absolute value of the difference is calculated as the difference) is recorded as the air volume measurement deviation value. Using this method, the air volume measurement deviation value measured by the static pressure method under different belt wear degrees at the same fan frequency can be obtained.

[0051] 3. Analyze the differences between all belt tension data obtained from real-time monitoring data and experimental monitoring data, and select multiple experimental monitoring data that are similar to the belt condition of the fan at different frequencies and the real-time monitoring data, so as to calculate the degree of deviation of the air volume value measured by the static pressure method in the real-time monitoring data at different frequencies.

[0052] In step 2 above, different degrees of belt wear were simulated using experimental methods, and the air volume measurement deviation value corresponding to each degree of belt wear was obtained.

[0053] Since wear is a continuous indicator, it is impossible to conduct experimental analysis on all wear levels. Therefore, this application uses the similarity of the collected tension data as the basis for comparing the belt wear levels between real-time monitoring data and experimental monitoring data.

[0054] Furthermore, considering the rotation of the belt, the instantaneous data collected by the belt tension measuring instrument may not accurately reflect the degree of belt wear. Therefore, in order to obtain more accurate measurement results, this application analyzes the belt tension data at each monitoring location for t consecutive monitoring times. The calculation method for the similarity of belt wear between the real-time monitoring data and experimental monitoring data of the fan at different frequencies is as follows:

[0055]

[0056] In the formula, This represents the similarity of belt wear between real-time monitoring data a and experimental monitoring data b when the centrifugal fan frequency is p. norm represents the normalization function, m represents the number of belt tension measuring instruments placed on the conveyor belt, and t represents the monitoring time length for each monitoring data point. This represents the belt tension data acquired by the real-time monitoring data 'a' at the j-th monitoring time of the belt tension measuring instrument at the i-th time. This represents the belt tension data obtained by the experimental monitoring data b at the j-th monitoring time of the belt tension measuring instrument at the i-th time. It should be understood that when the belt tension data obtained by the belt tension measuring instrument at each corresponding monitoring time of the real-time monitoring data a and the experimental monitoring data b are similar, it indicates that the similarity of belt wear between the real-time monitoring data a and the experimental monitoring data b is higher.

[0057] When the motor frequency is p in the real-time monitoring data, the similarity of belt wear is calculated by comparing the real-time monitoring data 'a' acquired in real time with the experimental monitoring data from each experiment. A similarity threshold H=0.9 is preset, and experimental monitoring data that are greater than the similarity threshold are recorded as experimental monitoring data with similar belt conditions.

[0058] Threshold filtering can filter out some real-time monitoring data a that are similar to the belt condition at the fan frequency p. Suppose there are k experimental monitoring data that are similar to the belt condition. Obtain the air volume measurement deviation value corresponding to these data. The normalized value of the average value of the air volume measurement deviation value corresponding to these k experimental monitoring data is denoted as the deviation degree PL of the air volume value measured by the static pressure method of the real-time monitoring data at the fan frequency p.

[0059] 4. And obtain real-time monitoring data based on the static pressure value measured by the static pressure method and the air volume value in the air volume-static pressure curve at the corresponding frequency.

[0060] The static pressure value measured by the static pressure method based on real-time monitoring data is substituted into the air volume-static pressure curve of the fan at the corresponding fan frequency to obtain the air volume value Fc measured in real time based on the static pressure method.

[0061] step Real-time air volume measurement based on wind speed method.

[0062] When using the anemometer method to measure air volume, the measurement results are mainly affected by the instability and non-uniformity of the cross-sectional wind speed. Therefore, this application obtains the wind speed uniformity and stability during the anemometer method measurement by analyzing real-time monitoring data, thereby obtaining the reliability of the measurement results.

[0063] 1. Determine wind speed stability based on the degree of fluctuation in wind speed data from all wind speed sensors.

[0064] In this embodiment, the variance of all wind speed data for each wind speed sensor during the data collection period is calculated. The mean of the variances calculated by all wind speed sensors is taken as the reciprocal and then normalized to obtain the wind speed stability.

[0065] First, wind speed data F is obtained from the same wind speed sensor over a time period of t. The wind speed data obtained by the first wind speed sensor is F1, where F1 = {V11, V12, ..., V1t}, and V11, V12, and V1t represent the wind speed data collected by the first wind speed sensor at the first, second, and t-th times, respectively. The variance of all wind speed data obtained by the same wind speed sensor within the collection period is calculated. That is, the smaller the variance of the obtained wind speed data, the stronger the wind speed stability at the corresponding point of the wind speed sensor.

[0066] For each of the n wind speed sensors located at the fan inlet, the variance of all wind speed data within a time period of length t is calculated, resulting in n variance values. The average of these n variance values ​​is then taken as the mean variance, and its reciprocal is used for normalization to obtain the wind speed stability. In this example, t = 20.

[0067] 2. Determine the uniformity of the distribution by using the disordered distribution of the fluctuation degree calculated from all wind speed sensors and the average distribution of the fluctuation degree calculated at all acquisition times.

[0068] In this embodiment, the variance of the variance values ​​calculated by all wind speed sensors is used as the first wind speed uniformity index; the wind speed variance of all wind speed sensors at each acquisition time is normalized and used as the wind speed uniformity at that time; the average value of the wind speed uniformity at all times is used as the second wind speed uniformity index; and the average value of the first and second wind speed uniformity indices is used as the distribution uniformity.

[0069] Specifically, the variance of the variance values ​​of n wind speed sensors is calculated as the first wind speed uniformity index. That is, the greater the difference in wind speed variation between different points, the worse the wind speed uniformity of each point in the cross section.

[0070] The analysis is based on the wind speed data collected by all sensors at each moment within a time period of length t. The variance of the wind speed collected by all sensors at the same moment is calculated. The larger the variance of the wind speed, the more uneven the wind speed at the outlet of the centrifugal fan at that moment. The wind speed variance is normalized and recorded as the wind speed uniformity at the outlet of the centrifugal fan at that moment. The average value of the wind speed uniformity at the outlet of the centrifugal fan acquired at t moments is recorded as the second wind speed uniformity index.

[0071] The distribution uniformity of the wind speed at the fan outlet at the current moment is obtained by averaging the first wind speed uniformity index and the second wind speed uniformity index.

[0072] 3. By positively integrating the wind speed stability index with the distribution uniformity, the reliability of real-time wind volume measurement based on the wind speed method is obtained.

[0073] The reliability Kf of the wind speed method for measuring air volume is obtained based on the wind speed stability index and distribution uniformity index acquired t time steps before the target time. Specifically, the more stable the wind speed at the centrifugal fan outlet and the more uniform the wind speed distribution at different locations, the greater the reliability Kf of the wind speed method for measuring air volume, indicating that the air volume obtained based on the wind speed method is more accurate and reliable. In this embodiment, the reliability Kf of the wind speed method for measuring air volume is obtained by multiplying the wind speed stability index and the distribution uniformity index.

[0074] 4. Using the average wind speed at the current moment and the cross-sectional area corresponding to the measurement position of the wind speed sensor, determine the air volume of the air outlet based on the real-time measurement of the wind speed method.

[0075] Specifically, the average wind speed value of all wind speed sensors collected at the current moment is multiplied by the cross-sectional area corresponding to the measurement position of the wind speed sensor to obtain the air volume of the outlet measured in real time based on the wind speed method.

[0076] The average wind speed value obtained by each wind speed sensor at the monitoring time is obtained, and it is multiplied by the cross-sectional area S of the air outlet to obtain the air volume Fv of the air outlet based on the wind speed method in real time.

[0077] step Comprehensive measurement of centrifugal fan air volume.

[0078] Based on the above information, this application obtains centrifugal fan measurement results based on both the wind speed method and the static pressure method. Considering their respective influencing factors, a more accurate centrifugal fan measurement result can be obtained by combining the two methods. The specific method is as follows:

[0079]

[0080] In the formula, Pw represents the final air volume of the centrifugal fan obtained by combining the static pressure method and the wind speed method, PL represents the deviation of the real-time monitoring data based on the air volume value measured by the static pressure method, Kf represents the reliability of the air volume measurement based on the wind speed method, Fc represents the air volume value measured in real time based on the static pressure method, and Fv represents the outlet air volume measured in real time based on the wind speed method.

[0081] It should be understood that the greater the deviation of the desired airflow value obtained based on the static pressure method, and the more reliable the airflow measurement based on the anemometer method, the more likely the measurement results can be obtained from the anemometer method in the real-time monitoring results. Conversely, the smaller the deviation of the desired airflow value obtained based on the static pressure method, and the less reliable the airflow measurement based on the anemometer method, the more likely the measurement results can be obtained from the static pressure method in the real-time monitoring results.

[0082] Therefore, by combining the air volume values ​​measured in real time by the static pressure method and the wind speed method, as well as the deviation and reliability of each measurement method, the final air volume of the centrifugal fan can be determined using the method described in this application.

[0083] Based on the same inventive concept as the centrifugal fan airflow monitoring method described above, another embodiment of this application provides a centrifugal fan airflow monitoring system, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the centrifugal fan airflow monitoring method described above.

[0084] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not invented in this application.

[0085] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A method for monitoring the air volume of a centrifugal fan, characterized in that, The method includes the following steps: Obtain the airflow-static pressure curves of the fan at different frequencies; obtain the airflow measurement deviation values ​​using the static pressure method from experiments on the belt under different wear levels; analyze the differences between all belt tension data obtained from real-time monitoring data and experimental monitoring data, and screen out multiple experimental monitoring data with belt conditions similar to those in the real-time monitoring data at different frequencies to calculate the degree of deviation of the airflow values ​​measured by the static pressure method in the real-time monitoring data at different frequencies; and obtain the airflow value in the airflow-static pressure curve of the real-time monitoring data measured by the static pressure method at the corresponding frequency. Based on the fluctuation of wind speed data from all wind speed sensors, wind speed stability is determined; the uniformity of distribution is determined by the chaotic distribution of fluctuation calculated from all wind speed sensors and the average distribution of fluctuation calculated at all acquisition times; the reliability of real-time airflow measurement based on the wind speed method is obtained by multiplying the wind speed stability index by the uniformity of distribution; and the airflow at the outlet measured in real-time based on the wind speed method is determined by using the average wind speed at the current moment and the cross-sectional area corresponding to the measurement position of the wind speed sensor. The method for determining wind speed stability is as follows: calculate the variance of all wind speed data for each wind speed sensor during the data collection period, take the reciprocal of the mean of the variances calculated by all wind speed sensors, and then normalize the data to obtain the wind speed stability. The method for determining the uniformity of distribution is as follows: the variance of the variance values ​​calculated by all wind speed sensors is used as the first wind speed uniformity index; the wind speed variance of all wind speed sensors at each acquisition time is normalized and used as the wind speed uniformity at that time; the average value of the wind speed uniformity at all times is used as the second wind speed uniformity index; and the average value of the first and second wind speed uniformity indices is used as the distribution uniformity. The final air volume of the centrifugal fan is determined by combining the real-time air volume values ​​measured by the combined static pressure method and the wind speed method, as well as the deviation and reliability of each measurement method.

2. The method for monitoring the air volume of a centrifugal fan as described in claim 1, characterized in that, The method for selecting multiple experimental monitoring data points of the fan at different frequencies that are similar to the belt condition data in real-time monitoring data is as follows: Based on the differences between real-time monitoring data and any experimental monitoring data at the same fan frequency, the similarity of belt wear between real-time monitoring data and any experimental monitoring data is determined. Experimental monitoring data with belt wear similarity greater than a preset similarity threshold are used as experimental monitoring data with belt condition similar to real-time monitoring data.

3. The method for monitoring the air volume of a centrifugal fan as described in claim 2, characterized in that, The method for determining the similarity of belt wear is as follows: Calculate the normalized value of the sum of the differences between real-time monitoring data and any experimental monitoring data obtained at the same fan frequency for all belt tension data; The difference between the value 1 and the normalized value is used as the similarity of belt wear between the real-time monitoring data and any experimental monitoring data at the same fan frequency.

4. The method for monitoring the air volume of a centrifugal fan as described in claim 2, characterized in that, The method for calculating the degree of deviation is as follows: The normalized value of the average air volume measurement deviation value corresponding to all experimental monitoring data with belt conditions similar to the real-time monitoring data at the same frequency is used as the degree of deviation of the air volume value measured by the static pressure method based on the real-time monitoring data at the same frequency.

5. The method for monitoring the air volume of a centrifugal fan as described in claim 1, characterized in that, Reliability is positively correlated with wind speed stability and distribution uniformity, respectively.

6. The method for monitoring the air volume of a centrifugal fan as described in claim 1, characterized in that, The method for determining the outlet air volume based on real-time measurement using the anemometer method is as follows: The average wind speed values ​​collected from all wind speed sensors at the current moment are multiplied by the cross-sectional area corresponding to the measurement location of the wind speed sensor to obtain the air volume at the outlet based on the wind speed method in real time.

7. The method for monitoring the air volume of a centrifugal fan as described in claim 1, characterized in that, The final method for determining the air volume of the centrifugal fan is as follows: In the formula, Pw represents the final air volume of the centrifugal fan obtained by combining the static pressure method and the wind speed method, PL represents the deviation of the real-time monitoring data based on the air volume value measured by the static pressure method, Kf represents the reliability of the air volume measurement based on the wind speed method, Fc represents the air volume value measured in real time based on the static pressure method, and Fv represents the outlet air volume measured in real time based on the wind speed method.

8. A centrifugal fan airflow monitoring system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements a centrifugal fan air volume monitoring method as described in any one of claims 1-7.

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