Iron core reactor capable of reducing resonance

Abstract

The invention belongs to the field of electric reactor noise reduction, and particularly discloses an iron core electric reactor capable of reducing resonance, which comprises an oil tank, an iron core assembly and a connecting assembly arranged in the oil tank, and a plurality of positioning nails arranged between the bottom of the oil tank and the iron core assembly, the connecting assembly comprises a foot pad arranged outside the positioning nail, a rubber pad arranged between the foot pad and the box bottom, an elastic assembly arranged above the foot pad and a steel washer arranged above the elastic assembly; the bottoms of the positioning nails are fixedly connected with the box bottom, and the tops of the positioning nails are connected with the iron core assembly through nuts. The soft wood rubber pad and the belleville spring are combined, the appropriate belleville spring is selected while the parameters of the soft wood rubber pad are adjusted, the difference between the inherent frequency of the connecting assembly and the vibration frequency of the electric reactor is large, resonance is avoided, even resonance is avoided, mechanical vibration is buffered, vibration is damped, noise is absorbed, and transmission of vibration and mechanical noise is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of reactor noise reduction, and in particular relates to an iron core reactor for reducing resonance. Background Art

[0002] The large vibration of the iron core reactor can easily damage the structural parts and components, endangering the safety of the power grid. At the same time, the mechanical noise generated by the vibration makes it extremely difficult to achieve the goal of substation boundary noise meeting the limit value stipulated in the Environmental Protection Law. In the existing technology, all reactors in the UHV projects built are equipped with soundproof enclosures, but the soundproof enclosures have a series of problems such as being unfavorable for fire protection. The current industry goal is to reduce the noise level of UHV reactors of 240,000 kvar and below to below 64dB(A). The IEC standard limit is 85dB(A). Compared with the IEC standard, it can be seen that this is an unprecedented global problem.

[0003] The connection between the body of the iron core reactor and the oil tank 1 becomes one of the key factors affecting vibration and noise. On the one hand, a relatively strong solid connection is necessary in the product structure. For example, when the body is placed on the oil tank 1, it falls on the upper surface of the tank bottom 101 and is strongly fixed to it, otherwise it will be displaced during transportation and operation. On the other hand, the solid connection is the main bridge for transmitting vibration and noise. The structure and connection method of the prior art are: the body has two feet 7 with holes at both ends and a lower crossbeam. Four positioning nails 5 are welded on the bottom 101 of the box corresponding to the holes of the feet 7 for fixing the body; the reinforcing iron support of the crossbeam is supported on the bottom 101 of the box, and the crossbeam with a thickness of about 3 mm is insulated. Therefore, the connection between the body and the bottom 101 of the box in the prior art is basically a rigid connection, which is a sound transmission bridge for vibration and noise to propagate from the body to the outside. See Figure 1 to Figure 2 , Figure 1 The single-phase iron core reactor body includes a body and an oil tank 1. Figure 2 It is a schematic diagram of the connection system between the foot 7 and the bottom 101 of the box. This rigid connection system is: the threaded positioning nail 5 welded to the bottom 101 is covered with an insulating tube, a layer of about 3mm thick cardboard is insulated and laid between the foot 7 of the device body and the interlayer of the bottom 101 of the box, the foot 7 with holes at both ends is covered outside the positioning nail 5 and the insulating tube, the upper part of the foot 7 is provided with an insulating washer 10 and a steel washer 9, and the positioning nail 5 is tightened with a nut 16. This connection system is similar to a rigid connection, which cannot absorb vibration and noise, and is a vibration and sound transmission bridge, which will obviously cause a lot of noise. When the iron core reactor resonates, it will cause great damage to the body of the device, and even resonance may occur, causing safety hazards and affecting the normal operation of the reactor. Summary of the invention

[0004] The invention provides an iron core reactor with reduced resonance, which is used to solve the problem that the current reactor cannot absorb vibration and noise and is a vibration and sound transmission bridge, which obviously causes relatively large noise.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: the iron core reactor for reducing resonance, wherein, comprises: an oil tank, an iron core assembly and a connecting assembly arranged in the oil tank, and a plurality of positioning pins arranged between the bottom of the oil tank and the iron core assembly;

[0006] The connecting assembly includes a foot arranged outside the positioning nail, a rubber pad arranged between the foot and the bottom of the box, an elastic assembly arranged above the foot, and a steel washer arranged above the elastic assembly;

[0007] The bottom of the positioning nail is fixedly connected to the box bottom, and the top of the positioning nail is connected to the core assembly through a nut.

[0008] In a preferred embodiment of the present invention, the core assembly includes an iron yoke in the shape of a "mouth" along the vertical plane, an iron core column arranged in the middle of the iron yoke, a coil wound outside the iron core column, and a lower clamp arranged at the bottom of the iron core column; the top of the positioning pin is fixed to the lower clamp by a nut.

[0009] In a preferred embodiment of the present invention, the connecting assembly further comprises an insulating washer disposed between the elastic assembly and the foot.

[0010] In a preferred embodiment of the present invention, the connection assembly further includes an insulating layer disposed between the rubber pad and the pad foot.

[0011] In a preferred embodiment of the present invention, an insulating tube is provided between the positioning pin and the foot, and the positioning pin is provided in the insulating tube.

[0012] In a preferred embodiment of the present invention, the elastic component includes a limiting cylinder and a disc spring, the bottom of the limiting cylinder is provided with a through hole for the positioning pin to pass through, and the disc spring is arranged in the limiting cylinder.

[0013] In a preferred embodiment of the present invention, the height H of the limiting cylinder is obtained by formula 1:

[0014] H=e+a+kx (1)

[0015] Among them, e is the thickness of the steel plate at the bottom of the limit cylinder; a is the length of the disc spring after being fully compressed, k is the limit coefficient, among which 0.71≤k≤0.75, and x is the stroke length of the disc spring.

[0016] In a preferred embodiment of the present invention, the total area S (unit: cm 2 ) is obtained by formula 2:

[0017] S=m / 9 (2)

[0018] Wherein, m is the mass of the device, unit: kg.

[0019] In a preferred embodiment of the present invention, the connection assembly further comprises an insulating support assembly, and the insulating support assembly is disposed between two adjacent pads.

[0020] In a preferred embodiment of the present invention, the insulating support assembly includes a crossbeam, a supporting steel plate disposed below the crossbeam, and an insulating plate disposed below the supporting steel plate.

[0021] In a preferred embodiment of the present invention, when the calculated total area S of the rubber pad is greater than the total area of ​​the pad feet, a rubber pad is arranged between the insulating plate and the box bottom.

[0022] The technical solution provided by the present invention has the following advantages compared with the prior art:

[0023] The present invention adopts a combination of a cork rubber pad and a disc spring, adjusts the parameters of the cork rubber pad and selects a suitable disc spring, so that the natural frequency of the connection assembly differs greatly from the vibration frequency of the reactor, avoids the formation of resonance or even resonance, and reduces the noise during the operation of the reactor. It can not only press at a constant pressure, but also give the device body a certain vertical movement space, so it can effectively release vibration energy, absorb sound waves, and reduce vibration and noise to a certain extent; at the same time, in the vertical direction, the connection here is prevented from being excessively rigid, forming a constant pressure positioning, buffering mechanical vibration, damping vibration, absorbing noise, thereby reducing the spread of vibration and mechanical noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of a reactor body in the prior art;

[0026] Figure 2 This is a schematic diagram of the connection system of the reactor in the prior art.

[0027] Figure 3 It is a schematic diagram of a body of an iron core reactor for reducing resonance described in one embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of a connection assembly of an iron core reactor for reducing resonance according to an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of a support assembly of an iron core reactor for reducing resonance according to an embodiment of the present invention;

[0030] Figure 6 It is a schematic diagram of the parameter positions of a disc spring of an iron core reactor for reducing resonance described in one embodiment of the present invention.

[0031] As shown in the figure:

[0032] 1- oil tank; 101- tank bottom; 2- iron yoke; 3- iron core column; 4- coil; 5- positioning nail; 6- insulating tube; 7- foot; 8- rubber pad; 9- steel washer; 10- insulating washer; 11- insulating layer; 12- crossbeam; 13- insulating plate; 14- limiting cylinder; 15- disc spring; 16- nut. DETAILED DESCRIPTION

[0033] For ease of understanding, the iron core reactor for reducing resonance is described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation and positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0037] like Figure 3 As shown, a resonance-reducing iron core reactor includes: an oil tank 1, an iron core assembly and a connecting assembly arranged in the oil tank 1, and a plurality of positioning pins 5 arranged between the bottom 101 of the oil tank 1 and the iron core assembly.

[0038] The core assembly includes an iron yoke 2 in the shape of a "mouth" along the vertical plane, an iron core column 3 arranged in the middle of the iron yoke 2, a coil 4 wound outside the iron core column 3, and a lower clamp arranged at the bottom of the iron core column 3; the top of the positioning pin 5 is fixed to the lower clamp by a nut 16.

[0039] The bottom of the positioning pin 5 is fixedly connected to the box bottom 101, and the top of the positioning pin 5 is connected to the core assembly through a nut 16. Figure 4 An insulating tube 6 is arranged between the positioning nail 5 and the pad foot 7, and the positioning nail 5 is arranged in the insulating tube 6.

[0040] The connection assembly includes a foot 7 disposed outside the positioning nail 5, a rubber pad 8 disposed between the foot 7 and the box bottom 101, an elastic assembly disposed above the foot 7, and a steel washer 9 disposed above the elastic assembly. The steel washer 9 is fixed above the foot 7 by a force wrench or hydraulic method.

[0041] Combination Figure 3-Figure 4 As shown, the connection assembly further includes an insulating gasket 10 disposed between the elastic assembly and the foot 7 and an insulating layer 11 disposed between the rubber pad 8 and the foot 7 .

[0042] Combination Figure 3 and Figure 5 As shown, the connection assembly further includes an insulating support assembly, which is disposed between two adjacent pads 7. The insulating support assembly includes a crossbeam 12, a support steel plate disposed below the crossbeam 12, and an insulating plate 13 disposed below the support steel plate.

[0043] The present invention combines the disc spring 15 with the rubber pad 8, and provides a certain vertical movement space for the device body under the required constant pressure, which can effectively release vibration energy, damp vibration, absorb sound waves, and reduce vibration and noise to a certain extent.

[0044] Reference Figure 4 As shown, the elastic component includes a limiting cylinder 14 and a disc spring 15 . A through hole for the positioning pin 5 to pass through is arranged at the bottom of the limiting cylinder 14 , and the disc spring 15 is arranged in the limiting cylinder 14 .

[0045] The height H of the limiting cylinder 14 is obtained by formula 1:

[0046] H=e+a+kx (1)

[0047] Wherein, e is the thickness of the steel plate at the bottom of the limiting cylinder 14; a is the length of the disc spring 15 after being fully compressed, k is the limiting coefficient, wherein 0.71≤k≤0.76, and x is the stroke length of the disc spring.

[0048] The total area S of the rubber pad 8 (unit: cm 2 ) is obtained by formula 2:

[0049] S=m / 9 (2)

[0050] Wherein, m is the mass of the device, unit: kg.

[0051] Reference Figure 3 As shown in FIG. 1 , when the calculated total area S of the rubber pad 8 is greater than the total area of ​​the foot 7, the rubber pad 8 is arranged between the insulating plate 13 and the box bottom 101. That is, if the area of ​​the cork rubber pad 8 arranged at the foot 7 is not enough to bear the pressure of about 9 kgf / cm 2 , it is necessary to add a cork rubber pad 8 at the crossbeam 12.

[0052] The present invention is applicable to single-phase iron core reactors and three-phase iron core reactors. Taking a single-phase reactor as an example, the body mass m, the static friction coefficient μ of the cork rubber pad 8, the pad foot 7 and the bottom 101 are known, and the noise reduction effect is best when the cork rubber withstands a pressure of 9 kg / cm2. The four positioning nails 5 are M42 / φ60, that is, round steel with a diameter of 60 mm, and one end is processed into an M42 thread for screwing the nut 16. The maximum acceleration allowed when the reactor is transported or carried is 3g.

[0053] Take the UHV reactor BKD-240000 / 1100 as an example. The body weight is 98 tons. There are two pads 7. The pads 7 are 2126 long and 220 wide. The crossbeam 12 is 1816 long and 700 wide. The steel plates in contact with the crossbeam 12 and the cork rubber are 2 steel plates with a length of 1816 and a width of 300. The cork rubber with a thickness of 60 and the same area is padded between the pads 7, the crossbeam 12 and the bottom 101 of the box. The static friction coefficient between it and the upper and lower surfaces is considered to be 0.4. Four M42 / φ60 positioning pins 5 are welded at the holes of the pads 7 on the bottom 101 of the box. The specifications of the disc spring 15 are shown in Tables 1 and 2. Figure 6 , refer to Table 1 and Table 2 to design the tightening pressure of the nut 16 at the positioning pin 5, the combination of the disc spring 15 and determine the limit cylinder 14.

[0054] Table 1 Dimensions and main parameters of disc spring 15

[0055]

[0056] Table 2 Deformation characteristics of disc spring 15

[0057]

[0058] For standardized design, several disc springs 15 of different capacities have been designed, which can be used alone or in combination. The combination means that the number of disc springs 15 in parallel can be adjusted to change the pressure by multiples, and the number of disc springs in series can be adjusted to change the total stroke by multiples. The disc springs 15 used in the present invention are non-standard parts specially designed according to specific needs.

[0059] The pressure 4F applied by the nut 16 in the connection system and the weight of the body are the total positive pressure N, which should make the cork rubber pad 8 withstand a pressure of about 9kgf / cm 2 , so as to achieve the best noise reduction effect, and secondly, provide positive pressure to create static friction between the device body and the bottom of the box 101, and then cooperate with other auxiliary positioning measures to ensure that the device body does not move when it is subjected to a horizontal acceleration of 3g.

[0060] Due to the addition of a thicker cork rubber pad 8 and a disc spring 15 placed in the limit tube 14, the pressure, stroke of the disc spring 15 and the depth of the limit tube 14 are accurately calculated as required, which prevents the connection here from being excessively rigid in the vertical direction, forms a constant pressure positioning, and buffers mechanical vibrations, thereby reducing the spread of vibration and mechanical noise.

[0061] Combination Figure 3-Figure 5 As shown in the figure, the disc spring 15 provides different forces when the stroke is compressed by different amounts. It has the best performance when the maximum stroke is compressed by about 75%, and cannot be flattened. In this way, the specifications of the disc spring 15 can be determined, and then the size of the limit cylinder 14 can be determined. For example, the disc spring 15 in Table 1 and Table 2, the stroke is compressed by 71%-75%, and the pressure F=196000N=20000kgf.

[0062] The positive pressure N is obtained by formula 3:

[0063] N=4F+G=4×20000+98000=178000kgf (3)

[0064] The maximum static friction force F2 is obtained by formula 4:

[0065] F2=μN=0.4×178000=71600kgf (4)

[0066] The maximum impact force F1 during transportation is obtained by formula 5:

[0067] F1=ma=3mg=3×98000=294000kgf (5)

[0068] The inner diameter of the disc spring 15 is 43.2, the outer diameter is 108, and the height after the three disc springs are compressed in parallel is 20. The limiting cylinder 14 is designed accordingly.

[0069] The contact area S between the foot pad 7, the cross beam 12 and the cork rubber is obtained by formula 6:

[0070] S=22×212.6×2+181.6×30×2=20250.4cm 2 (6)

[0071] The pressure of cork rubber is P = N / S = 178000 / 20250.4 = 8.8 kgf / cm 2 , and 9kgf / cm 2 The closer it is, the better the shock absorption effect.

[0072] The present invention adopts the combination of cork rubber pad 8 and disc spring 15, adjusts the parameters of cork rubber pad 8 and selects suitable disc spring 15, so that the natural frequency of the connection assembly is greatly different from the vibration frequency of the reactor, avoiding the formation of resonance or even resonance, and reducing the noise during the operation of the reactor. It can not only press with constant pressure, but also give the body of the device a certain vertical movement space, so it can effectively release vibration energy, absorb sound waves, and reduce vibration and noise to a certain extent; at the same time, in the vertical direction, the connection here is prevented from being excessively rigid, forming constant pressure positioning, buffering mechanical vibration, damping vibration, absorbing noise, thereby reducing the spread of vibration and mechanical noise.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An iron core reactor for reducing resonance, characterized in that: include: An oil tank, an iron core assembly and a connecting assembly arranged in the oil tank, and a plurality of positioning pins arranged between the bottom of the oil tank and the iron core assembly; The connecting assembly includes a foot arranged outside the positioning nail, a rubber pad arranged between the foot and the bottom of the box, an elastic assembly arranged above the foot, and a steel washer arranged above the elastic assembly; The bottom of the positioning nail is fixedly connected to the box bottom, and the top of the positioning nail is connected to the core assembly through a nut.

2. The iron core reactor for reducing resonance according to claim 1, characterized in that: The core assembly includes an iron yoke in the shape of a "mouth" along the vertical plane, an iron core column arranged in the middle of the iron yoke, a coil wound outside the iron core column, and a lower clamp arranged at the bottom of the iron core column; the top of the positioning nail is fixed to the lower clamp by a nut.

3. The iron core reactor for reducing resonance according to claim 1, characterized in that: The connecting assembly also includes an insulating washer arranged between the elastic assembly and the pad foot.

4. The iron core reactor for reducing resonance according to claim 1, characterized in that: The connection assembly also includes an insulating layer arranged between the rubber pad and the pad foot.

5. The iron core reactor for reducing resonance according to claim 1, characterized in that: An insulating tube is arranged between the positioning nail and the pad foot, and the positioning nail is arranged in the insulating tube.

6. The iron core reactor for reducing resonance according to claim 1, characterized in that: The elastic component includes a limiting cylinder and a disc spring. The bottom of the limiting cylinder is provided with a through hole for the positioning pin to pass through, and the disc spring is arranged in the limiting cylinder.

7. The iron core reactor for reducing resonance according to claim 6, characterized in that: The height H of the limiting cylinder is obtained by formula 1: H=e+a+kx (1) Among them, e is the thickness of the steel plate at the bottom of the limit cylinder; a is the length of the disc spring after being fully compressed, k is the limit coefficient, among which 0.71≤k≤0.75, and x is the stroke length of the disc spring.

8. The iron core reactor for reducing resonance according to claim 1, characterized in that: The total area S of the rubber pad (unit: cm 2 ) is obtained by formula 2: S=m / 9 (2) Wherein, m is the mass of the device, unit: kg.

9. The iron core reactor for reducing resonance according to claim 8, characterized in that: The connection assembly also includes an insulating support assembly, and the insulating support assembly is arranged between two adjacent pads.

10. The iron core reactor for reducing resonance according to claim 9, characterized in that: The insulating support assembly includes a crossbeam, a supporting steel plate arranged below the crossbeam, and an insulating plate arranged below the supporting steel plate.

11. The iron core reactor for reducing resonance according to claim 10, characterized in that: When the calculated result of the total area S of the rubber pad is greater than the total area of ​​the pad feet, a rubber pad is arranged between the insulating plate and the box bottom.

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