A hierarchical alarm method and system adapted to fan resonance

Abstract

The application discloses a hierarchical alarm method and system suitable for fan resonance, and relates to the technical field of wind power. The method comprises the following steps: performing a fan frequency knock test, calculating the average natural frequency of all blades and the natural frequency of the fan; calculating the rotating frequency under the rated rotating speed according to the rated rotating speed, and calculating the rotating frequency and the passing frequency under different rotating speeds; comparing the rotating frequency and the passing frequency under different rotating speeds with the natural frequency of the fan to determine the resonance interference rotating speed; establishing a scoring system and calculating the score of the current operating state; determining the alarm level according to the score of the current operating state and triggering the alarm. The application makes a comprehensive judgment from the overall characteristics of the system, gives a warning on the vibration caused by the resonance, and can be further expanded and compatible with automatic adjustment means to realize the integrated automatic control of alarm and avoidance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power technology, and particularly to a hierarchical alarm method and system adapted to wind turbine resonance. BACKGROUND

[0002] In the current power industry, speed regulation operation of rotating machinery is widely used, not only on large fans, but also on high-power pumps. However, when the rotating machine adopts speed regulation operation, its inherent frequency will inevitably interfere with the rotating frequency and the passing frequency to cause resonance. When resonance is excited, it will cause great harm to the equipment itself. In recent years, the frequent blade rupture, main shaft rupture and bearing damage accidents of power plant fans are mostly caused by resonance, which seriously affects the safety and economic benefits of power enterprises, and also causes great obstacles to social livelihood and industrial development.

[0003] With the current technology, it is almost impossible to eliminate the resonance of the equipment. For the equipment whose resonance frequency has been determined, it can still be avoided by adjusting means. Even so, as the equipment operates, wear and tear, dust accumulation and other factors will cause changes in its inherent frequency, so it needs to be adjusted regularly according to the actual situation of the equipment, which has great limitations. SUMMARY

[0004] In view of the problem that when resonance is excited, it will cause great harm to the equipment itself, the present application is proposed.

[0005] Therefore, the problem to be solved by the present application is how to make a comprehensive evaluation alarm strategy based on the analysis of the inherent frequency and the difficulty of resonance excitation and the intensity of harm under the condition that the inherent frequency of the equipment is known.

[0006] To solve the above technical problems, the present application provides the following technical solutions:

[0007] In a first aspect, the present application provides a hierarchical alarm method adapted to wind turbine resonance, which comprises: performing a wind turbine frequency knock test, calculating the average inherent frequency of all blades and the inherent frequency of the wind turbine; calculating the rotating frequency under the rated rotating speed according to the rated rotating speed, and calculating the rotating frequency and the passing frequency under different rotating speeds; comparing the rotating frequency and the passing frequency under the different rotating speeds with the inherent frequency of the wind turbine to determine the resonance interference rotating speed; establishing a scoring system and calculating the score of the current operating state; determining the alarm level according to the score of the current operating state and triggering the alarm and recording.

[0008] As a preferred embodiment of the graded alarm method adapted to wind turbine resonance described in this invention, the calculation of the average natural frequency of all blades includes the following steps: selecting m0 test points on the wind turbine blades; performing a tapping test at each test point using an eddy current sensor; recording the first to nth natural frequencies of each test point; and calculating the average natural frequency of the blade by averaging the squared data of the m0 test points; wherein m0 is a constant.

[0009] As a preferred embodiment of the graded alarm method adapted to wind turbine resonance described in this invention, the natural frequency of the wind turbine is calculated by arithmetically squaring the natural frequencies of all blades.

[0010] As a preferred embodiment of the graded alarm method adapted to wind turbine resonance described in this invention, wherein: the calculation of the rotational frequency based on the rated operating speed is: based on the rated operating speed n e Calculate the rotational frequency (Hertz):

[0011] υ r =n e / 60

[0012] Based on the number of fan blades M, calculate the passing frequency of the fan at its rated speed:

[0013] υ t =υ r ×M

[0014] Calculating the rotational frequency and throughput frequency at different operating speeds includes: deriving the N times υ of the fan at rated speed based on the ratio relationship. t and υ r When the fan speed increases from 0 to below the rated speed... e Then there will be (0,1,2,...,n) e The rotational frequency and the passing frequency are denoted as υ. t，N and υ r，N .

[0015] As a preferred embodiment of the graded alarm method adapted to wind turbine resonance described in this invention, the scoring system includes a vibration monitoring condition score (POV), a resonance excitation score (PORE), and a resonance speed deviation score (DORE); the scoring system is calculated using a (PORE×DORE+POV) scoring method.

[0016] As a preferred embodiment of the graded alarm method adapted to wind turbine resonance described in this invention, wherein: when the scoring system is implemented, the wind turbine operation is subject to the following conditions: if the wind turbine speed is located at the core position where resonance occurs, i.e. And the vibration exceeds the alarm value; if the fan speed is located at the core position of resonance, that is... But the vibration does not exceed the alarm value; if the fan speed is located at the higher position of resonance occurrence But the vibration exceeds the alarm value; if the fan speed is located at the higher position of resonance occurrence But the vibration does not exceed the alarm value; if the fan speed is located at the safe position But the vibration exceeds the alarm value; different scores are output according to different fan operation conditions.

[0017] As a preferred scheme of the grading alarm method adapted to fan resonance, the alarm comprises: setting a multi-color alarm, displaying an alarm button on a DCS screen, and performing entry accumulation statistics of alarm time in the background.

[0018] In a second aspect, the embodiment of the present application provides a grading alarm system adapted to fan resonance, which comprises: a frequency knock test module, used for performing fan frequency knock test, calculating the average natural frequency of all blades, and obtaining the natural frequency of the fan; a rotating frequency calculation module, used for calculating the rotating frequency under the rated rotating speed according to the rated rotating speed, and calculating the rotating frequency and the passing frequency under different rotating speeds; a frequency matching and resonance detection module, used for comparing the rotating frequency and the passing frequency under the different rotating speeds with the natural frequency of the fan, and determining the resonance interference speed; a sub-system module, used for establishing a scoring system, and calculating the score of the current operating state; and an alarm triggering and recording module, used for determining the alarm level according to the score of the current operating state, and triggering the alarm.

[0019] In a third aspect, the embodiment of the present application provides a computer device, comprising a memory and a processor, and the memory stores a computer program, wherein: the computer program instructions are executed by the processor to realize the steps of the grading alarm method adapted to fan resonance according to the first aspect of the present application.

[0020] In a fourth aspect, the embodiment of the present application provides a computer readable storage medium, which stores a computer program, wherein: the computer program instructions are executed by the processor to realize the steps of the grading alarm method adapted to fan resonance according to the first aspect of the present application.

[0021] The present application has the following beneficial effects: according to the known resonance frequency, combined with a certain avoidance rate and the real-time monitoring data of the vibration of the fan, the present application adopts a comprehensive scoring mechanism to perform alarm, gives the operating personnel with the operation warning of the device, and according to the same current and historical state of the device, judges the vibration jump generated at present, and issues a warning, and collects information in the comprehensive scoring mechanism to perform alarm. It can be seen that the present application makes a comprehensive judgment from the overall characteristics of the system, and gives a warning to the vibration condition of resonance, and can continue to expand and be compatible with automatic adjustment means, to realize the integrated automatic control of alarm + avoidance. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0023] Fig. 1 The hierarchical alarm configuration diagram adapted to the fan resonance.

[0024] Fig. 2 The schematic diagram of the knocking point of the fan blade. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0026] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from the description, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0027] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an independent or selective embodiment that excludes other embodiments.

[0028] Embodiment 1

[0029] Reference Figs. 1-2 For the first embodiment of the present application, the embodiment provides a hierarchical alarm method adapted to fan resonance, comprising,

[0030] S1: Perform fan frequency knocking test, calculate the average natural frequency of all blades and the natural frequency of the fan.

[0031] S1.1: Select m0 test points on the fan blade, wherein m0 of the present application is 4 (TAP POINT 1-4).

[0032] Among them, the test point is located at 1 / 2 of the blade height h, and the four test points are located at 1 / 5h, 2 / 5h, 3 / 5h and 4 / 5h of the blade height h respectively.

[0033] S1.2: Use an eddy current sensor to perform knocking test at each test point.

[0034] As Fig. 2 shown, the eddy current sensor is adsorbed at each TAP POINT position, and a knock is applied to the blade to excite the natural frequency (υ g，1x ~υ g，nx ) of the blade itself, wherein υ g，1x represents the 1st order natural frequency of the blade, and υ g，nx represents the n-th order natural frequency of the blade.

[0035] S1.3: Record and calculate the natural frequency of each blade.

[0036] Record the 1st to n-th order natural frequencies (υ g，1x，1 ~υ g，nx，1 , υ g，1x，2 ~υ g，nx，2 , υ g，1x，3 ~υ g，nx，3, , υ g，1x，4 ~υ g，nx，4 , etc.) of each test point, square average the data of the four test points, and obtain the average natural frequency (υ g，1x，avg ~υ g，nx，avg ) of the blade.

[0037] S1.4: Calculate the average natural frequency of all blades to obtain the natural frequency of the fan.

[0038] Arithmetically square the natural frequencies of all blades to finally obtain the natural frequency υ g,f，1x ~υ g, f ，nx of the fan.

[0039] S2: Calculate the rotational frequency at the rated rotational speed according to the rated rotational speed, and calculate the rotational frequency and the passing frequency at different rotational speeds.

[0040] Preferably, the rotational frequency is calculated according to the rated rotational speed n e : υ r = n e / 60, which is in Hz (Hertz), and combined with the number of blades M of the fan, the passing frequency of the fan at the rated rotational speed is calculated:

[0041] υ t = υ r × M

[0042] At the same time, according to the multiple relationship, the N times υ t and υ r of the fan at the rated rotational speed can be obtained;

[0043] Similarly, when the rotational speed of the fan is increased from 0 to the rated rotational speed n e, there will be (0, 1, 2,..., n e ) rotation frequencies and pass frequencies, denoted as υ t，N and υ r，N .

[0044] S3: compare the rotation frequency and pass frequency at different running speeds and the inherent frequency of the fan to determine the resonance interference rotation.

[0045] Compare the calculated rotation frequency υ t，N , pass frequency υ r，N and its multiple frequency with the inherent frequency of the fan, when it is close to or even equal to the inherent frequency of a certain order of the fan, it is considered that the rotation frequency υ r，N and the pass frequency υ t，N corresponding to the fan speed is the resonance interference speed.

[0046] S4: Establish a scoring system and calculate the score of the current running state.

[0047] From Fig. 1 It can be seen that the configuration of the present application mainly consists of three parts, including: POV is the vibration monitoring condition score, which evaluates the vibration output monitored by the system in real time and outputs the evaluation result;

[0048] PORE is the resonance excitation score, which correctly selects the monitoring speed and converts through the function when the monitoring speed reaches res1x~res4x, the output evaluation of the speed gear.

[0049] DORE is the resonance speed deviation score, which evaluates the deviation degree between the selected resonance speed interval and the actual speed, and finally obtains the evaluation.

[0050] From the intensity of resonance, the general principle is that regardless of the resonance phenomenon induced by any reason, it should be avoided, and the lower the order of the inherent frequency of the equipment, the easier the resonance is excited, and the higher the order, the more difficult the resonance phenomenon is excited, so the resonance phenomenon caused by the inherent frequency of the equipment should be rated according to the difficulty of excitation, that is, the resonance caused by the first order inherent frequency is rated as first level, and so on, the resonance caused by the fourth order inherent frequency is rated as fourth level.

[0051] The inherent frequencies of 1~4 orders of the equipment are defined as Res 1X ~Res 4X , then the resonance rating caused by the excitation Res 1X ~Res 4X is defined as Lvr1~Lvr4.

[0052] Simultaneously, the rotation speed that will excite the resonance of the equipment is defined as Rev, and there can be more than one rotation speed point that can excite the resonance in a rotating machine, and according to the number of rotation speed points, it is defined as Rev1-Rev n1 , wherein n1 is the number of resonance rotation speed points.

[0053] Further, the resonance excitation condition score (PORE) is:

[0054] According to the difficulty of excitation of the natural frequency, Rev n Res 1X -Res 4X The phenomenon of interference between the stages is assigned 7-4 points in turn, and generally Res 1X is the most easily excited, and the score is 4, Res 4X is the most difficult to be excited, and the score is 7.

[0055] The resonance rotation speed deviation condition score (DORE) is:

[0056] According to the deviation degree of the resonance rotation speed, when the deviation degree of the actual running speed of the fan and the resonance rotation speed is within 1%, it is recorded as 5 points; when the deviation degree is within 3%, it is recorded as 4 points; when the deviation degree is within 5%, it is recorded as 3 points; and other rotation speed intervals are recorded as 0 points.

[0057] , wherein the deviation degree of the deviation degree is the ratio of any one of the rotation speed n x of the fan to the actual rotation speed n s of the fan, recorded as:

[0058]

[0059] The vibration monitoring condition score (POV) is:

[0060] According to the DCS monitoring vibration data, 10 points are reached when the alarm value is reached, 8 points are reached when 80% of the alarm value is reached, and so on.

[0061] Preferably, the calculation of the scoring system includes:

[0062] The scoring method of (PORE×DORE+POV) is adopted.

[0063] When the system is implemented, the operation of the fan will present the following situations:

[0064] a. If the rotation speed of the fan is located in the core position of the resonance occurrence, i.e. and the vibration exceeds the alarm value, the system score output is 45 points;

[0065] b. If the rotation speed of the fan is located in the core position of the resonance occurrence, i.e. But the vibration does not exceed the alarm value, the system score output is 40 points;

[0066] c. If the fan speed is located in the higher position of resonance occurrence, that is, But the vibration exceeds the alarm value, the system score output is 34 points;

[0067] d. If the fan speed is located in the higher position of resonance occurrence But the vibration does not exceed the alarm value, the system score output is 29 points;

[0068] e. If the fan speed is located in the safe position But the vibration exceeds the alarm value, the system score output is: 10 points.

[0069] S5: According to the score of the current running state, determine the alarm level, and trigger the alarm and record.

[0070] Specifically, the score is greater than or equal to 40 points, which is a red alarm, indicating that the fan has entered the resonance core point and has a greater impact on the fan operation;

[0071] The score is greater than or equal to 20 points and less than 40 points, which is an orange alarm, indicating that the fan has entered a high resonance area and has a certain impact on the fan operation;

[0072] The score is greater than 10 points and less than 20 points, which is a yellow alarm, indicating that the fan has just entered the resonance range, but the monitoring data does not necessarily reflect the abnormality of the fan running state.

[0073] The score is less than or equal to 10 points, which is a green running state, indicating that the fan is not running in the resonance area, and the score of the fan only shows the vibration influence caused by other factors of the fan.

[0074] The red, orange and yellow alarms not only display the alarm button on the DCS screen, but also should be in the background to enter the alarm time cumulative statistics.

[0075] Further, the embodiment also provides a hierarchical alarm system adapted to fan resonance, comprising,

[0076] The frequency knock test module is used for performing fan frequency knock test, calculating the average natural frequency of all blades, and obtaining the natural frequency of the fan;

[0077] The rotating frequency calculation module calculates the rotating frequency under the rated speed according to the rated running speed, and calculates the rotating frequency and the passing frequency under different running speeds;

[0078] The frequency matching and resonance detection module compares the rotating frequency and the passing frequency under different running speeds with the natural frequency of the fan to determine the resonance interference speed.

[0079] a subsystem module for establishing a scoring system and calculating a score of the current running state;

[0080] an alarm triggering and recording module for determining an alarm level according to the score of the current running state and triggering an alarm.

[0081] The embodiment also provides a computer device suitable for the hierarchical alarm method adapted to fan resonance, which comprises a memory and a processor; the memory is used for storing computer executable instructions, and the processor is used for executing the computer executable instructions to realize the hierarchical alarm method adapted to fan resonance as proposed in the above embodiment.

[0082] The computer device can be a terminal, which comprises a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. The processor of the computer device is used for providing computing and control capabilities. The memory of the computer device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used for wired or wireless communication with external terminals. The wireless communication can be realized through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball or touchpad arranged on the shell of the computer device, or an external keyboard, touchpad or mouse, etc.

[0083] The embodiment also provides a storage medium having a computer program stored thereon, which is executed by a processor to realize the hierarchical alarm method adapted to fan resonance as proposed in the above embodiment.

[0084] In summary, according to the known resonance frequency, in combination with a certain avoidance rate and real-time vibration monitoring data of the fan, the comprehensive scoring mechanism is adopted to perform alarm, to give an operation warning of the device to the operator, to judge the vibration jump generated at present according to the current and historical states of the device under the same operation, to issue a warning, and to collect information in the comprehensive scoring mechanism to perform alarm. It can be seen that the comprehensive judgment is made from the overall characteristics of the system, and the vibration condition of resonance is warned. The subsequent automatic adjustment means can be compatible, to realize the integrated automatic control of alarm + avoidance.

[0085] Embodiment 2

[0086] Reference Fig. 1 and Fig. 2For the second embodiment of the present application, the embodiment provides a hierarchical alarm method adapted to fan resonance. In order to verify the beneficial effects of the present application, scientific demonstration is carried out through experiments.

[0087] In order to verify the effectiveness of the hierarchical alarm method adapted to fan resonance, three fans of FX3000 type are selected as test objects, named as fan A, fan B and fan C. The test mainly verifies the resonance characteristics of the fan at different speeds through the measurement and analysis of the natural frequency of the fan blade and the resonance point of the fan, and realizes the alarm triggering through the scoring system.

[0088] Firstly, the electric eddy current sensor is used for the knocking test of the fan blade. Four test points (TAP POINT 1-4) are arranged on each blade, which are located at 1 / 5h, 2 / 5h, 3 / 5h and 4 / 5h of the blade height and 1 / 2 of the width w. After the natural frequency of each test point is calculated by exciting the natural frequency of the blade, the square average of the data is obtained to get the average value of the natural frequency of each blade. Then, the arithmetic square of the average value of the natural frequency of all blades is calculated to obtain the natural frequency of the whole fan.

[0089] The rotation frequency ur and the passing frequency ut of the fan are calculated through the rated speed of the fan. At the same time, the resonance frequency change at different speeds is recorded in the process of the speed from 0 to the rated speed, and the key resonance interference speed area is marked.

[0090] By comparing the rotation frequency, passing frequency and its multiple of the fan with the natural frequency of the fan, the speed of the fan in the resonance area is identified, and the scoring system is used to score the running state of the fan. The three elements of the score include the vibration monitoring condition score (POV), the resonance excitation score (PORE) and the resonance speed deviation score (DORE), which are evaluated according to different speeds and vibration conditions.

[0091] Finally, the scoring system triggers the corresponding alarm level and records the alarm time according to different score values. When the score exceeds 40 points, the red alarm is triggered, indicating that the fan is in a serious resonance state; when the score is 2040 points, the orange alarm is triggered, indicating that the fan is in a higher resonance influence area; when the score is 1020 points, the yellow alarm is triggered; and when the score is less than or equal to 10 points, the green alarm is triggered, indicating that the fan is running normally.

[0092] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A method of graduated alerting adapted to fan resonance, characterized in that: Comprising, performing a fan frequency knock test, calculating the average natural frequency of all blades and the fan natural frequency; calculating the rotational frequency at the rated operating speed according to the rated operating speed, and calculating the rotational frequency and the passing frequency at different operating speeds; comparing the rotational frequency and the passing frequency at the different operating speeds and the fan natural frequency to determine the resonance interference rotation; establishing a scoring system and calculating the score of the current operating state; determining the alarm level according to the score of the current operating state and triggering an alarm; when the scoring system is implemented, the fan operation has the following situations: if the fan speed is in the core position of resonance occurrence, i.e. the deviation is ≤3%, and the vibration exceeds the alarm value; if the fan speed is in the core position of resonance occurrence, i.e. the deviation is ≤3%, but the vibration does not exceed the alarm value; if the fan speed is in the higher position of resonance occurrence, i.e. 3% < deviation ≤5%, but the vibration exceeds the alarm value; if the fan speed is in the higher position of resonance occurrence, i.e. 3% < deviation ≤5%, but the vibration does not exceed the alarm value; if the fan speed is in the safe position, i.e. the deviation is >5%, but the vibration exceeds the alarm value; output different scores according to different fan operating conditions; the alarm includes: setting a three-color alarm, displaying an alarm button on the DCS screen, and performing background alarm time entry accumulation statistics to calculate the cumulative time of the fan entering the resonance interval, provide data basis for the interval of the fan impeller inspection.

2. The hierarchical alarm method adapted to fan resonance of claim 1, wherein: The calculation of the average natural frequency of all blades includes the following steps: selecting m0 test points on the fan blades; using an eddy current sensor to perform a knock test at each test point; recording the 1st to n-th natural frequency of each test point, and performing square averaging on the data of the m0 test points to calculate the average natural frequency of the blade; wherein m0 is a constant.

3. The hierarchical alarm method adapted to fan resonance of claim 2, wherein: The calculation of the fan natural frequency is by arithmetic square of the natural frequencies of all blades.

4. The hierarchical alarm method adapted to fan resonance of claim 3, wherein: The calculation of the rotational frequency according to the rated operating speed is: According to the rated operating rotational speed n e Calculated rotational frequency (Hz): υ r = n e / 60 combined with the number of fan blades M, the passing frequency of the fan at the rated speed is calculated: υ t = υ r x M The calculation of the rotational frequency and the passing frequency at different operating speeds includes: According to the relationship of the ratio, the N times of υ of the fan under the rated speed is obtained t and υ r ; When the fan speed is raised from 0 to the rated operating speed n e then there are 0, 1, 2,..., n e rotational frequencies and through frequencies, denoted by υ t，N and υ r，N .

5. The hierarchical alarm method adapted to fan resonance of claim 4, wherein: The scoring system includes vibration monitoring condition score POV, resonance excitation score PORE and resonance speed deviation score DORE; The scoring system uses a scoring method of resonance excitation score × resonance speed deviation score + vibration monitoring condition score.

6. A hierarchical alarm system adapted to fan resonance, based on the hierarchical alarm method adapted to fan resonance according to any one of claims 1 to 5, characterized in that: Further comprising, a frequency knock test module for performing a fan frequency knock test, calculating the average natural frequency of all blades, and obtaining the fan natural frequency; a rotational frequency calculation module for calculating the rotational frequency at the rated operating speed according to the rated operating speed, and calculating the rotational frequency and the passing frequency at different operating speeds; a frequency matching and resonance detection module for comparing the rotational frequency and the passing frequency at the different operating speeds and the fan natural frequency to determine the resonance interference rotation; a subsystem module for establishing a scoring system and calculating the score of the current operating state; an alarm triggering and recording module for determining the alarm level according to the score of the current operating state and triggering an alarm. 7.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is characterized in that: The computer program is executed by the processor to realize the steps of the hierarchical alarm method adapted to fan resonance of any one of claims 1-5.

8. A computer readable storage medium having stored thereon a computer program, characterized in that: The computer program is executed by the processor to realize the steps of the hierarchical alarm method adapted to fan resonance of any one of claims 1-7.

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