Transformer oil tank wall

Abstract

The utility model provides an oil tank wall of a transformer. The oil tank wall of the transformer comprises an inner-layer tank wall and an outer-layer tank wall, the outer-layer tank wall is arranged outside the inner-layer tank wall in the length direction of the oil tank, a buffering energy-absorbing cavity is defined between the outer-layer tank wall and the inner-layer tank wall, the buffering energy-absorbing cavity is filled with buffering energy-absorbing materials, and rib plates are further arranged in the buffering energy-absorbing cavity; the upper box edge and the lower box edge are arranged at the top end and the bottom end of the inner-layer box wall respectively, and supporting reinforcing ribs are arranged between the upper box edge and the top of the outer-layer box wall and between the lower box edge and the bottom of the outer-layer box wall respectively. The outer-layer tank wall is arranged outside the inner-layer tank wall to form the composite tank wall, the rib plates and the buffer energy-absorbing materials are arranged between the outer-layer tank wall and the inner-layer tank wall, and the supporting reinforcing ribs are arranged among the upper tank edge, the lower tank edge and the inner-layer tank wall, so that the transformer oil tank wall forms a rigid-flexible composite supporting network; and an anti-impact protection mechanism of combining hardness and softness is realized, so that the cooperative improvement of static pressure strength and dynamic anti-impact performance is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of power equipment, specifically, relates to a transformer oil tank wall. BACKGROUND

[0002] The design of the traditional extra-high voltage transformer oil tank wall mainly focuses on meeting the static pressure strength requirement (such as positive pressure 120kPa, negative pressure 13Pa), and usually adopts single thickening steel plate or locally added rigid support structure. However, under extreme working conditions such as internal high-energy arc fault, instantaneous shock wave will form a high-strength mechanical stress field on the surface of the oil tank wall, causing local stress concentration of the inner wall, which is easy to cause cracks and even rupture, causing serious accidents such as insulation oil leakage and fire. In the prior art, although the thickness of the tank wall is simply increased to improve the static pressure bearing capacity, the plastic deformation space of the material is significantly reduced, and the energy absorption efficiency is weakened; and the dense arrangement of the rigid support structure may cause the overall tank wall to be "too rigid", and the stress transmission is intensified due to the lack of buffering mechanism under dynamic impact, thereby increasing the risk of rupture. In addition, the traditional design is not optimized according to the differentiated load characteristics of highway and railway transportation, and is easy to cause structural fatigue or installation conflict due to vibration or size limitation. SUMMARY

[0003] In view of this, the utility model provides a transformer oil tank wall, which aims to solve the problem that the existing oil tank wall is difficult to optimize the static pressure strength and dynamic impact resistance performance.

[0004] The utility model provides a transformer oil tank wall, which comprises an inner tank wall, an outer tank wall arranged outside the inner tank wall along the length direction of the oil tank, a buffer energy absorption cavity formed between the outer tank wall and the inner tank wall, a buffer energy absorption material filled in the buffer energy absorption cavity, and a rib plate arranged in the buffer energy absorption cavity for providing local rigidity support, an upper tank edge and a lower tank edge arranged at the top end and the bottom end of the inner tank wall respectively, and a support reinforcing rib arranged between the upper tank edge, the lower tank edge and the top and bottom of the outer tank wall respectively to form a rigid support network with the support reinforcing rib, the rib plate and the outer tank wall to suppress stress diffusion.

[0005] Further, the outer tank wall of the above-mentioned transformer oil tank wall is a long rectangular shell structure with one end open, and the four side plates thereof are connected with the inner tank wall.

[0006] Further, the buffer energy absorption material is installed in the buffer energy absorption cavity by interference filling process, or the buffer energy absorption material and the inner wall of the buffer energy absorption cavity are connected by adhesive.

[0007] Further, the transformer oil tank wall, the inner layer tank wall is made of Mn13 plastic steel material, and the yield strength is greater than or equal to 300 MPa.

[0008] Further, the transformer oil tank wall, the outer layer tank wall is made of Q345B steel material, and the yield strength is greater than or equal to 400 MPa.

[0009] Further, the transformer oil tank wall, the outer wall of the part of the inner layer tank wall exposed outside the buffer energy absorption cavity and the outer wall of the outer layer tank wall is provided with an outer wall reinforcing rib.

[0010] Further, the transformer oil tank wall, the inner layer tank wall is made of a plurality of modules and is welded, and the welding seams of the inner layer tank wall are arranged in the vertical direction, and each welding seam is located in the buffer energy absorption material coverage range.

[0011] Further, the transformer oil tank wall, the cross section of the supporting reinforcing rib is trapezoidal or rectangular.

[0012] Further, the transformer oil tank wall, the outer layer tank wall and the inner layer tank wall are connected by welding.

[0013] Further, the transformer oil tank wall, the outer layer tank wall and the inner layer tank wall are connected by bolt riveting.

[0014] The transformer oil tank wall provided by the utility model forms a composite tank wall through setting the outer layer tank wall outside the inner layer tank wall, and setting the rib plate and the buffer energy absorption material between the two, and the supporting reinforcing rib set between the upper tank edge, the lower tank edge and the inner layer tank wall makes the transformer oil tank wall form a rigid-flexible composite support network, realizes the impact protection mechanism of "rigid and flexible", and further realizes the synergistic improvement of static pressure strength and dynamic impact resistance, and solves the problem that the existing oil tank wall is difficult to synergistically optimize the static pressure strength and the dynamic impact resistance. BRIEF DESCRIPTION OF DRAWINGS

[0015] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments with reference made to the accompanying drawings. The drawings are for purposes of illustration only and are not considered a limitation of the present utility model. Moreover, like reference numerals are used to designate identical parts throughout the specification and drawings. In the drawings:

[0016] Fig. 1 The top view of the transformer oil tank wall provided by the utility model embodiment is shown in the figure;

[0017] Fig. 2 The side view of the transformer oil tank wall provided by the utility model embodiment is shown in the figure;

[0018] Fig. 3The utility model provides a structure schematic view of the highway transportation transformer oil tank wall provided by the embodiment of the utility model.

[0019] Fig. 4 The utility model provides a structure schematic view of the railway transportation transformer oil tank wall provided by the embodiment of the utility model.

[0020] Mark explanation: 1 - inner layer tank wall, 2 - outer layer tank wall, 3 - rib plate, 4 - buffering energy-absorbing material, 5 - upper tank along, 6 - lower tank along, 7 - support reinforcing rib, 8 - outer wall reinforcing rib. DETAILED DESCRIPTION

[0021] Exemplary embodiments of the present disclosure will be described in greater detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be accurately conveyed to those skilled in the art. It should be noted that the embodiments in the utility model and the features in the embodiments can be combined with each other without conflict. The utility model will be described in detail below with reference to the drawings and in combination with the embodiments.

[0022] Reference Figs. 1 to 4 It shows the preferred structure of the transformer oil tank wall provided by the embodiment of the utility model. As shown in the figure, the transformer oil tank wall comprises: an inner layer tank wall 1, an outer layer tank wall 2, a rib plate 3, a buffering energy-absorbing material 4, an upper tank along 5, a lower tank along 6, a support reinforcing rib 7 and an outer wall reinforcing rib 8.

[0023] The outer layer tank wall 2 is arranged outside the inner layer tank wall 1 along the length direction of the oil tank, a buffering energy-absorbing cavity is formed between the outer layer tank wall 2 and the inner layer tank wall 1, the buffering energy-absorbing cavity is filled with the buffering energy-absorbing material 4, and the buffering energy-absorbing cavity is also provided with the rib plate 3 for providing local rigidity support.

[0024] Specifically, the inner tank wall 1 can be made of a steel material with good plasticity, for example, Mn13 plastic steel material, the thickness of the inner tank wall 1 can be reduced by 1-2mm compared with the traditional design, and part of the impact energy can be absorbed by controllable deformation. The yield strength of the inner tank wall 1, i.e. the tensile strength, is greater than or equal to 300MPa. The outer tank wall 2 is arranged in the high failure risk area of the oil tank in the long axis direction, and the outer tank wall 2 can be made of Q345B steel material with high yield strength, and the yield strength, i.e. the tensile strength, is greater than or equal to 400MPa. The outer tank wall 2 can be a long rectangular shell structure with one end open, and the four side plates are connected with the inner tank wall 1 to form a rectangular structure buffer energy absorbing cavity. The buffer energy absorbing material 4 is filled between the inner tank wall 1 and the outer tank wall 2, and the buffer energy absorbing material 4 is fixed between the inner tank wall 1 and the outer tank wall 2 by interference connection or glueing. That is, the buffer energy absorbing material 4 is installed in the buffer energy absorbing cavity by interference filling process, or the buffer energy absorbing material 4 is connected with the inner wall of the buffer energy absorbing cavity by glueing. The elastic modulus and yield strength of the buffer energy absorbing material 4 are selected by simulation optimization to ensure controllable deformation in the static pressure stage and high energy dissipation in the dynamic impact stage. The elastic modulus of the buffer energy absorbing material 4 can be 1-5GPa, and the yield strength can be 1-20MPa. The rib plate 3 can be uniformly welded between the inner tank wall 1 and the outer tank wall 2, and the number of the rib plate 3 can be 8-15 to provide local stiffness support.

[0025] The upper tank edge 5 and the lower tank edge 6 are respectively arranged at the top end and the bottom end of the inner tank wall 1, and the upper tank edge 5 and the lower tank edge 6 are respectively provided with a support reinforcing rib 7 between the top and bottom of the outer tank wall 2. Specifically, the upper tank edge 5 is arranged between the inner tank wall 1 and the tank cover to realize the connection therebetween; the lower tank edge 6 is arranged between the inner tank wall 1 and the tank bottom plate to realize the connection therebetween. The support reinforcing rib 7 is further arranged between the upper tank edge 5 and the top end of the inner tank wall 1, and the support reinforcing rib 7 is also arranged between the lower tank edge 6 and the bottom end, i.e. the bottom, of the inner tank wall 1, that is, the support reinforcing rib 7 connects the outer tank wall 2 with the upper and lower tank edges, and the cross section is trapezoidal or rectangular to further optimize the bending resistance and improve the connection stability. The support reinforcing rib 7 can be arranged along the whole circumference of the inner tank wall 1, or can be arranged in the risk area. The spacing of the inner tank wall 1 is 200-500mm to improve the overall bending resistance. Further preferably, the spacing of the support reinforcing rib 7 can be 300mm to improve the overall stiffness.

[0026] In the embodiment, to further improve the stability of the transformer oil tank wall, preferably, the outer wall of the part of the inner tank wall 1 exposed outside the buffer energy absorption cavity and the outer layer tank wall 2 is provided with an outer wall reinforcing rib 8, the outer wall reinforcing rib 8, the rib plate 3 and the outer layer tank wall 2 form a rigid support network to inhibit stress diffusion, and in combination with the buffer energy absorption material 4, a rigid-flexible composite support network is formed. Specifically, the outer wall reinforcing rib 8 is a box-shaped structure with one side open and hollow, and the cross section can be rectangular or trapezoidal structure, which can be fixedly installed on the outer wall of the part of the inner tank wall 1 exposed outside the buffer energy absorption cavity and the outer layer tank wall 2 by welding. Wherein, the arrangement interval of the outer wall reinforcing rib 8 can be determined according to the actual situation.

[0027] In the embodiment, the inner layer tank wall 1 is made by modular butt welding, and the weld seams of the inner layer tank wall 1 are arranged in the vertical direction, and each of the weld seams is located within the coverage range of the buffer energy absorption material 4. Specifically, the vertical direction weld seam is used when the inner layer tank wall 1 is butt welded, to avoid the weld seam crossing or being arranged in the corner area of the tank wall, and all the weld seams are located within the coverage range of the buffer energy absorption material 4, to reduce the risk of stress concentration. Wherein, the butt welding of the inner layer tank wall 1 can adopt TIG welding, i.e. tungsten inert gas welding, and the weld seam flaw detection qualified rate is ≥99.5%.

[0028] In the embodiment, the finite element model of the transformer oil tank wall is distributedly optimized to obtain the optimized design parameters satisfying the constraint conditions; wherein, the constraint conditions include: static pressure deformation constraint condition and dynamic impact constraint condition; the optimized design parameters include: thickness of the buffer energy absorption material, yield strength of the buffer energy absorption material, number of the rib plates; the static pressure deformation constraint condition is that the transformer oil tank wall deformation under positive pressure 120 kPa and negative pressure 13 Pa is less than or equal to 3 times the thickness of the inner layer tank wall; the dynamic impact constraint condition is that when the inner layer tank wall bears 80 MJ arc fault energy impact, the ratio of the material dynamic ultimate strain to the plastic working strain should be greater than or equal to k; wherein, when the voltage level exceeds 800 kV, k>1.4; when the voltage level exceeds 1000 kV, k>1.5.

[0029] Specifically, the finite element model of the transformer oil tank wall is distributedly optimized, the static simulation model and the explosion impact dynamic simulation model can be established by using ansys finite element simulation software respectively, the structure parameters are optimized, so that the static pressure deformation and the dynamic strain satisfy the constraint conditions. When the static simulation model is established, the following static pressure deformation constraint equation is established based on the finite element simulation: wherein, t is the thickness of the inner layer tank wall 1, the transformer oil tank wall deformation under positive pressure 120 kPa and negative pressure 13 Pa. When the explosion impact dynamic simulation model is established, the dynamic impact plastic strain constraint equation is established as follows: ; wherein, The plastic strain of the inner tank wall under 80 MJ arc fault energy is 0.8, The material limit value can be a safety factor value, when the voltage level exceeds 800 kV, k > 1.4; when the voltage level exceeds 1000 kV, k > 1.5. In optimization, the number of ribs, thickness, thickness and yield strength of the buffer energy-absorbing material are used as variables, and the optimal parameter combination is determined through iterative simulation.

[0030] The highway transport oil tank and the railway transport oil tank are described in detail below.

[0031] The highway transport oil tank can include: an inner tank wall 1, an outer tank wall 2, a rib 3, a buffer energy-absorbing material 4, an upper tank edge 5, a lower tank edge 6, a support stiffener 7 and an outer wall stiffener 8, the inner tank wall 1, the outer tank wall 2, the rib 3, the buffer energy-absorbing material 4 and the outer wall stiffener 8 form a rigid-flexible composite support network. The support stiffener 7 is arranged between the upper tank edge 5, the lower tank edge 6 and the inner tank wall 1, and the bending resistance is optimized through trapezoidal or rectangular cross-section design. The inner tank wall 1 is made of Mn13 plastic steel material, the thickness is 10 mm, which is reduced by 2 mm compared with the traditional design, and the vertical weld is used when the inner tank wall 1 is welded, the weld is away from the corner area, and all located in the coverage range of the buffer energy-absorbing material 4. The outer tank wall 2 is arranged in the high fault risk area of the long axis direction of the oil tank, which is made of Q345B steel material, the thickness is 12 mm, and is connected with the inner tank wall 1 through full penetration welding. The outer wall stiffener 8 connects the outer tank wall 2 with the upper tank edge 5 and the lower tank edge 6, the cross-section is rectangular, the spacing is 300 mm, and the overall stiffness is improved. The highway transport oil tank can be distributed and optimized. The parameters are that the deformation amount is ≤3 times the inner wall thickness under the positive pressure of 120 kPa and the negative pressure of 13 Pa in the static pressure stage, and the number, thickness and buffer material parameters of the rib are determined through finite element simulation; the plastic strain of the inner wall under 80 MJ arc fault energy is ≤0.8 times the material limit value in the dynamic impact stage, and the yield strength of the buffer material and the rib distribution are optimized. The buffer energy-absorbing material 4 is filled between the inner and outer tank walls, the thickness is 200 mm, the elastic modulus is 5 GPa, the yield strength is 10 MPa, and is fixed through interference fit. The rib 3 is uniformly welded between the inner tank wall 1 and the outer tank wall 2, the number is 8, the thickness is 10 mm, and the spacing is 600 mm. The inner tank wall 1 is welded by TIG welding, and the weld detection qualified rate is ≥99.5%. The outer tank wall 2 is welded before transportation, to ensure the overall sealing performance and fatigue resistance of the structure.

[0032] The railway transportation oil tank can include: inner tank wall 1, outer tank wall 2, rib plate 3, buffer energy-absorbing material 4, upper tank edge 5, lower tank edge 6, support stiffener 7 and outer wall stiffener 8, the inner tank wall 1 is made of Mn13 plastic steel material, the thickness is 10mm, which is reduced by 2mm compared with the traditional design, the inner tank wall 1 is welded by using vertical weld, the weld is avoided from the corner area, and is located in the coverage range of the buffer energy-absorbing material 4. The outer tank wall 2 is connected with the inner tank wall 1 by bolted flange connection, the bolt is M20 high-strength locking bolt, the pre-tightening force is 80kN, the interval is 150mm, the outer tank wall is made of Q345B steel material, and the yield strength is higher. The outer wall stiffener 8 is 10 in number and 16mm in thickness, and the section is rectangular. The support stiffener 7 is trapezoidal in section and 250mm in interval.

[0033] The railway transportation oil tank can be distributed and optimized. In the static pressure stage, the deformation is constrained to be less than or equal to 2.5 times the thickness of the inner wall, and the constraint is about 2.5 times the thickness of the inner wall. The number, thickness and buffer material parameters of the rib plate are determined by finite element simulation; in the dynamic impact stage, the inner wall plastic strain is less than or equal to 0.8 times the material limit value under 80MJ arc fault energy, and the buffer material yield strength and rib plate distribution are optimized. The buffer energy-absorbing material 4 is filled between the inner and outer tank walls, the thickness is 150mm, the yield strength is increased to 20MPa, and the adhesive process is used for fixation. The rib plate 3 is uniformly welded between the inner tank wall 1 and the outer tank wall 2, the number is 12, the thickness is 12mm, and the interval is 500mm. The local stiffness is enhanced by densification arrangement. Among them, the bolted flange connection adopts high-strength locking design, and the pre-tightening force and interval are verified by finite element simulation to ensure the stability of the connection under vibration conditions; the outer tank wall installation can be carried out on site to avoid the size constraint of railway transportation during transportation, and the size limitation of railway transportation is adapted.

[0034] To sum up, the transformer oil tank wall provided by the embodiment forms a composite tank wall by arranging an outer tank wall outside an inner tank wall, arranging a rib plate and a buffer energy-absorbing material between the two, arranging a support stiffener between the upper tank edge, the lower tank edge and the inner tank wall, so that the transformer oil tank wall forms a rigid-flexible composite support network, realizes an impact-resistant protection mechanism of “rigid and flexible combination”, and further realizes the synergistic improvement of static pressure strength and dynamic impact resistance, thereby solving the problem that the existing oil tank wall is difficult to synergistically optimize the static pressure strength and dynamic impact resistance.

[0035] It should be noted that, in the description of the utility model, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the direction or positional relationship terms based on the direction or positional relationship shown in the drawings, which is merely for the convenience of description, and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0036] In addition, it needs to be explained that, in the description of the utility model, unless another explicit provision and limitation, the term "installation", "connection", "connect" should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected; can be directly connected, also can be indirectly connected through the intermediate medium, can be two elements inside the communication. For those skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.

[0037] Obviously, those skilled in the art can make various modifications and variations to the utility model without departing from the spirit and scope of the utility model. Thus, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and its equivalent technologies, the utility model also intends to include these modifications and variations.

Claims

1. A transformer tank wall, characterized in that The transformer oil tank wall comprises: an inner tank wall; an outer tank wall arranged outside the inner tank wall along the length direction of the oil tank, a buffer energy absorption cavity being formed between the inner tank wall and the outer tank wall, the buffer energy absorption cavity being filled with a buffer energy absorption material, and a rib plate being arranged in the buffer energy absorption cavity for providing local rigidity support; an upper tank edge and a lower tank edge arranged at the top end and the bottom end of the inner tank wall respectively, and a support reinforcing rib being arranged between the upper tank edge and the top of the outer tank wall and between the lower tank edge and the bottom of the outer tank wall respectively, so that the support reinforcing rib, the rib plate and the outer tank wall form a rigid support network to inhibit stress propagation.

2. The transformer oil tank wall according to claim 1, wherein the outer tank wall is a cuboid shell structure with one end open, and four side plates of the outer tank wall are connected to the inner tank wall.

3. The transformer oil tank wall according to claim 1 or 2, wherein the buffer energy absorption material is installed in the buffer energy absorption cavity by an interference filling process, or the buffer energy absorption material is connected to the inner wall of the buffer energy absorption cavity by adhesive bonding.

4. The transformer oil tank wall according to claim 1 or 2, wherein the inner tank wall is made of Mn13 plastic steel material, and the yield strength of the inner tank wall is ≥300 MPa.

5. The transformer oil tank wall according to claim 1 or 2, wherein the outer tank wall is made of Q345B steel material, and the yield strength of the outer tank wall is ≥400 MPa.

6. The transformer oil tank wall according to claim 1 or 2, wherein an outer wall reinforcing rib is arranged on the outer wall of the outer tank wall and the part of the inner tank wall exposed outside the buffer energy absorption cavity.

7. The transformer oil tank wall according to claim 1 or 2, wherein the inner tank wall is made by modular tailor-welding, and the weld seams of the inner tank wall are arranged in the vertical direction, and each of the weld seams is located within the coverage range of the buffer energy absorption material.

8. The transformer oil tank wall according to claim 1 or 2, wherein the cross section of the support reinforcing rib is trapezoidal or rectangular.

9. The transformer oil tank wall according to claim 1 or 2, wherein the outer tank wall and the inner tank wall are connected by welding.

10. The transformer oil tank wall according to claim 1 or 2, wherein the outer tank wall and the inner tank wall are connected by bolted joint. ​ ​ ​ ​ ​ ​ ​ ​ ​

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