A fan base, a fan overall device and a fan vibration control method

Abstract

The present invention specifically relates to a fan base, the stiffness of which is improved by diagnosing the faults existing in the existing fan base according to the modal vibration data of the model; a wire rope isolator is provided on the fan base. The fan base provided by the present invention effectively isolates and reduces the vibration of the fan, and improves the reliability of the fan operation.

Description

Technical Field

[0001] The invention relates to the technical field of fan control in nuclear power plants, and in particular to a fan base, a fan overall device and a fan vibration control method. Background Art

[0002] In the fans running in nuclear power plants, the manifestation of frequent failures is excessive vibration (flexible connection vibration standard ≤ 5.5mm / s). After analysis, it is believed that the rigidity of the fan base is insufficient, and the rubber vibration isolator of the fan is prone to aging, and the vibration isolation performance is reduced. According to the existing overall equipment weight and the rigidity of the rubber vibration isolator, the system natural frequency is about 11Hz, which is high and the vibration isolation effect is not ideal. In addition, the location of the rubber vibration isolator is obviously unreasonable and eccentric, which will cause vibration coupling during vibration, which is not conducive to vibration response control. Summary of the invention

[0003] Based on this, it is necessary to provide a fan base, fan overall equipment and fan vibration control method to address the problem of excessive excitation speed of fan bases in factories and mines, so as to effectively isolate and reduce fan vibration and improve the reliability of fan operation.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A fan base, the rigidity of which is improved by diagnosing faults existing in an existing fan base based on modal vibration data of a model; a wire rope vibration isolator is provided on the fan base.

[0006] Working principle: The fan base of the present invention improves the first-order natural frequency of the fan base by improving the stiffness characteristics. The wire rope vibration isolator reduces the first-order natural frequency of the fan base and improves the vibration isolation efficiency of the fan base.

[0007] Furthermore, the modal vibration data of the model is obtained by performing SOLIDWORKS modeling on the existing fan base according to the actual status of the on-site fans in factories and mines, and performing modal analysis on the model using the finite element method.

[0008] Furthermore, the order of the modal vibration shape is 10th order.

[0009] Furthermore, the fan base is ensured to have a modal frequency significantly higher than the fan interference frequency through modal calculation, thereby preventing the fan base from generating resonance; and the fan base is manufactured by a steel plate welding process.

[0010] Furthermore, the fan base is connected to the wire rope vibration isolator by bolts.

[0011] Furthermore, the model and quantity of the wire rope vibration isolator on the fan base are selected based on the sum of the weights of the motor, fan and fan base, and the natural frequency of the fan is adjusted to the peak response frequency F of the overall equipment. r .

[0012] Furthermore, the peak response frequency F of the overall device r Greater than or equal to 4Hz, less than or equal to 5Hz.

[0013] Furthermore, the calculation formula for selecting the model and quantity of the wire rope isolator is as follows:

[0014]

[0015] In the formula, f r is the peak response frequency of the whole equipment, in Hz; K is the static stiffness of a single vibration isolator, in N / m; a is the dynamic stiffness coefficient of a single vibration isolator; m is the bearing mass of a single vibration isolator, in kg.

[0016] The present invention also provides an integrated fan device, comprising a fan, a motor and the fan base.

[0017] The present invention also provides a fan vibration control method, comprising the following steps:

[0018] 1. According to the actual status of the fans on site in factories and mines, SOLIDWORKS modeling is performed on the existing fan base, and the modal analysis of the model is performed using the finite element method to obtain the modal vibration shape of the model;

[0019] 2. Diagnose the faults of the existing fan base according to the modal vibration data of the model and adjust the stiffness of the fan base;

[0020] 3. Calculate and select the appropriate type and quantity of wire rope vibration isolators based on the sum of the weight of the motor, fan and fan base, and adjust the natural frequency of the fan to the peak response frequency of the entire equipment;

[0021] 4. According to the center of gravity of the motor, fan and fan base, the center of gravity of the whole equipment is obtained, and the installation position of the wire rope vibration isolator is reasonably arranged according to the principle of moment balance;

[0022] 5. Implement on-site according to the above steps;

[0023] The fan base is the above-mentioned fan base, and the overall equipment is the above-mentioned overall equipment.

[0024] Beneficial technical effects of the present invention.

[0025] The fan vibration control device and method of the present invention improve the first-order natural frequency of the fan base by improving the stiffness characteristics of the fan base, and significantly improve the first-order natural frequency of the fan base from 98.995HZ to 231.94HZ; and reduce the system natural frequency by using a suitable type of wire rope isolator through calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the 10th order natural frequency response diagram of the fan vibration when using the existing fan base;

[0027] Figure 2 is a 10th order natural frequency response diagram of the fan vibration when the fan base of the present invention is used;

[0028] Figure 3 It is a schematic diagram of the structure of the fan base of the present invention;

[0029] Figure 4 It is the vibration transmission curve diagram of the whole equipment;

[0030] Figure 5 This is the static mechanical performance curve of the wire rope isolator.

[0031] In the figure, 1. the fan base of the present invention; 2. the wire rope vibration isolator. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] See also Figure 3 The present invention provides a fan base 1, the stiffness of which is improved by diagnosing the faults existing in the existing fan base based on the modal vibration data of the model; a wire rope vibration isolator 2 is provided on the fan base 1.

[0034] Working principle: The fan base 1 of the present invention improves the first-order natural frequency of the fan base 1 by improving the stiffness characteristics. The wire rope vibration isolator 2 reduces the first-order natural frequency of the fan base 1 and improves the vibration isolation efficiency of the fan base 1.

[0035] Furthermore, the modal vibration data of the model is obtained by performing SOLIDWORKS modeling on the existing fan base according to the actual status of the on-site fans in factories and mines, and performing modal analysis on the model using the finite element method. The modal vibration data of the model includes the natural frequency of the existing fan base and the corresponding modal vibration shape.

[0036] Furthermore, the order of the modal vibration shape is 10th order.

[0037] Furthermore, the fan base 1 is ensured to have a modal frequency significantly higher than the fan interference frequency through modal calculation, thereby preventing the fan base 1 from generating resonance; the fan base 1 is formed by steel plate welding to increase overall rigidity.

[0038] Furthermore, the fan base 1 is connected to the wire rope vibration isolator 2 by bolts.

[0039] Furthermore, the model and quantity of the wire rope vibration isolator 2 on the fan base 1 are selected based on the sum of the weights of the motor, the fan and the fan base 1, and the natural frequency of the fan is adjusted to the peak response frequency F of the overall equipment. r .

[0040] Furthermore, the peak response frequency F of the overall device r Greater than or equal to 4Hz, less than or equal to 5Hz.

[0041] Furthermore, the calculation formula for selecting the model and quantity of the wire rope vibration isolator 2 is as follows:

[0042]

[0043] In formula (1), f r is the peak response frequency of the whole equipment, in Hz; K is the static stiffness of a single vibration isolator, in N / m; a is the dynamic stiffness coefficient of a single vibration isolator; m is the bearing mass of a single vibration isolator, in kg.

[0044] The vibration transmissibility of the overall device is calculated according to the following formula:

[0045]

[0046] In formula (2), x is the response amplitude; Χ0 is the excitation amplitude; ζ is the damping ratio, which is 0.15; λ is f i / f r The value of f i is the external excitation frequency or interference frequency; f r It is the natural frequency of the whole device and also the peak response frequency of the whole device.

[0047] See also Figure 2 , when λ is greater than 6, the system will produce a vibration reduction effect. It can be seen that when the external interference frequency is greater than 5.9Hz, the entire device enters the vibration isolation area, and when it is greater than 12.6Hz, the system achieves a relatively ideal vibration isolation effect, and the vibration isolation efficiency is 80%. The actual excitation frequency of the entire device is about 25Hz, the frequency ratio λ is about 6, and the vibration isolation effect can reach more than 95%.

[0048] The present invention further provides an integrated fan device, comprising a fan, a motor and the fan base 1 mentioned above.

[0049] The present invention also provides a fan vibration control method, using the above-mentioned fan base 1 and the fan overall device, comprising the following steps:

[0050] 1. According to the actual status of the fans on site in factories and mines, SOLIDWORKS modeling is performed on the existing fan base, and the modal analysis of the model is performed using the finite element method to obtain the modal vibration shape of the model;

[0051] 2. Diagnose the faults of the existing fan base according to the modal vibration data of the model and adjust the stiffness of the fan base;

[0052] 3. Calculate and select appropriate types and quantities of wire rope vibration isolators 2 according to the sum of the weights of the motor, fan and fan base 1, and adjust the natural frequency of the fan to the peak response frequency of the entire equipment;

[0053] 4. According to the center of gravity of the motor, fan and fan base, the center of gravity of the whole equipment is obtained, and the installation position of the wire rope vibration isolator is reasonably arranged according to the principle of moment balance;

[0054] 5. Implement on-site according to the above steps.

[0055] Furthermore, the excitation frequency of the fan=the rotation speed of the motor / 60s, the unit of the excitation frequency of the fan is Hz, and the unit of the rotation speed of the motor is r / min.

[0056] The first-order natural frequency of the existing fan base is 98.995Hz. The existing fan base is equipped with rubber shock absorbers. As the rubber shock absorbers age, they harden, resulting in an increase in the stiffness coefficient, which in turn increases the peak response frequency of the overall equipment. The vibration of the existing fan fluctuates around 7mm / s. The natural frequency of the existing overall equipment is about 11Hz, which is high and the vibration isolation effect is not very ideal. There is an obvious unreasonable distribution of the rubber shock absorbers, and there is eccentricity. Vibration coupling will occur during vibration, which is not conducive to vibration response control.

[0057] The first-order natural frequency of the fan base 1 of the present invention is greatly increased to 231.94 Hz, and the dynamic stiffness characteristics of the fan base 1 are improved.

[0058] See also Figure 2 The fan base 1 of the present invention is provided with a wire rope vibration isolator 2, and the first to sixth order natural frequencies of the overall equipment are all lower than the corresponding natural frequency values ​​of the existing overall equipment. The vibration of the fan of the present invention is reduced to ≤2mm / s and is stable, which is much lower than the flexible connection vibration standard of 5.5mm / s.

[0059] Based on the above effects, the equipment and method of the present invention have promotion significance for dealing with similar problems in other factories and mining enterprises.

[0060] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A fan base, characterized in that: The stiffness of the fan base (1) is improved by diagnosing the faults existing in the existing fan base based on the modal vibration data of the model, thereby improving the first-order natural frequency of the fan base (1); a wire rope vibration isolator (2) is provided on the fan base (1); the fan base (1) ensures that the modal frequency of the fan base (1) is higher than the fan interference frequency through modal calculation, thereby preventing the fan base from generating resonance; the model and number of the wire rope vibration isolators (2) on the fan base (1) are selected based on the sum of the weights of the motor, the fan and the fan base, and the natural frequency of the fan is adjusted to the peak response frequency F of the overall equipment. r , a fan overall device, including a fan, a motor and a fan base; the peak response frequency F of the overall device r Greater than or equal to 4Hz, less than or equal to 5Hz.

2. The fan base according to claim 1, characterized in that: The modal vibration data of the model are obtained by performing SOLIDWORKS modeling on the existing fan base according to the actual state of the fan on site in the factory and mine enterprise, and performing modal analysis on the model using the finite element method.

3. The fan base according to claim 2, characterized in that: The order of the modal vibration shape is 10th order.

4. The fan base according to claim 2, characterized in that: The fan base (1) is manufactured by using a steel plate welding process.

5. The fan base according to claim 1, characterized in that: The fan base (1) is connected to the wire rope vibration isolator (2) via bolts.

6. The fan base according to claim 1, characterized in that: The calculation formula for selecting the model and quantity of the wire rope vibration isolator (2) is as follows: , where f r is the peak response frequency of the whole equipment, in Hz; K is the static stiffness of a single vibration isolator, in N / m; a is the dynamic stiffness coefficient of a single vibration isolator; m is the bearing mass of a single vibration isolator, in kg.

7. A fan integrated device, comprising a fan, a motor and a fan base, characterized in that: The fan base is the fan base according to any one of claims 1 to 6.

8. A fan vibration control method, characterized in that: The steps include: Step 1: According to the actual status of the fans on site in factories and mines, SOLIDWORKS modeling is performed on the existing fan base, and the modal analysis of the model is performed using the finite element method to obtain the modal vibration shape of the model; Step 2: diagnose the faults existing in the existing fan base according to the modal vibration data of the model, and adjust the stiffness of the fan base (1); Step 3: Calculate and select appropriate types and quantities of wire rope vibration isolators based on the sum of the weights of the motor, the fan and the fan base (1), and adjust the natural frequency of the fan to the peak response frequency of the entire device; Step 4: According to the center of gravity of the motor, fan and fan base (1), the center of gravity of the entire device is obtained, and the installation position of the wire rope vibration isolator (2) is reasonably arranged according to the principle of moment balance; Step 5: Implement on-site according to the above steps; The fan base (1) is the fan base described in any one of claims 1 to 6, and the overall device is the overall device described in claim 7.

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