Thermal deformation simulation method of superconducting cable under different laying channel conditions
阅读说明：本技术 一种不同敷设通道条件下超导电缆的热变形仿真方法 (Thermal deformation simulation method of superconducting cable under different laying channel conditions ) 是由 焦婷 许经纬 李艳 孟毓 魏本刚 谢伟 郑健 于 2021-08-23 设计创作，主要内容包括：一种不同敷设通道条件下超导电缆的热变形仿真方法,其特征在于,所述方法包括以下步骤：步骤1,采集超导电缆敷设的工程示意图,并从所述工程示意图中提取所述超导电缆的敷设轨迹图；步骤2,基于所述超导电缆的敷设轨迹图,将所述超导电缆划分为超导电缆段,并为每一超导电缆段绘制三维模型；步骤3,采用铜材电缆近似等效所述超导电缆,并基于所述三维模型仿真获得所述铜材电缆轴向变形量结果。本发明中的方法,能够充分考虑到超导电缆在敷设过程中,复杂环境因素对其造成的影响,并提供具有电缆敷设参考性的仿真结果。(A thermal deformation simulation method of a superconducting cable under different laying channel conditions is characterized by comprising the following steps: step 1, collecting an engineering schematic diagram of superconducting cable laying, and extracting a laying track diagram of the superconducting cable from the engineering schematic diagram; step 2, dividing the superconducting cable into superconducting cable sections based on the laying track diagram of the superconducting cable, and drawing a three-dimensional model for each superconducting cable section; and 3, adopting a copper material cable to be approximately equivalent to the superconducting cable, and obtaining an axial deformation result of the copper material cable based on the three-dimensional model simulation. The method can fully consider the influence of complex environmental factors on the superconducting cable in the laying process, and provides a simulation result with cable laying reference.)
1. A thermal deformation simulation method of a superconducting cable under different laying channel conditions is characterized by comprising the following steps:
step 1, collecting an engineering schematic diagram of superconducting cable laying, and extracting a laying track diagram of the superconducting cable from the engineering schematic diagram;
step 2, dividing the superconducting cable into superconducting cable sections based on the laying track diagram of the superconducting cable, and drawing a three-dimensional model for each superconducting cable section;
and 3, adopting a copper material cable to be approximately equivalent to the superconducting cable, and obtaining an axial deformation result of the copper material cable based on the three-dimensional model simulation.
2. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 1, wherein:
the superconducting cable is a three-core superconducting cable, and each section of the superconducting cable is connected by a straight working well or a corner working well.
3. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 2, wherein:
a copper material cable with the diameter of 9mm is adopted to approximate a three-core superconducting cable with the equivalent weight of 15 t/km.
4. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 3, wherein:
the equivalent method for the copper material cable to be approximately equivalent to the superconducting cable comprises the following steps:
and under the condition of the same temperature variation amplitude, simulating or testing the deformation of the copper material cable and the superconducting cable, and realizing the approximate equivalence of the copper material cable to the superconducting cable when the deformation of the copper material cable and the superconducting cable is equal or similar.
5. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 4, wherein:
and performing modeling and simulation in advance on the typical laying condition of the superconducting cable, and acquiring the deformation and equivalent stress of the superconducting cable under different typical laying conditions.
6. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 5, wherein:
and simulating the superconducting cables under different laying conditions by referring to the deformation and the equivalent stress of the superconducting cables.
7. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 6, wherein:
the laying condition of the superconducting cable comprises the following steps: u-shaped horizontal laying, S-shaped horizontal laying and height difference laying.
8. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 7, wherein:
the deformation amount of the copper cable includes the deformation amount in the X, Y, Z axial direction.
9. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 8, wherein:
and calculating the axial deformation of the copper material cable based on the deformation of the copper material cable in the X, Y, Z axial direction.
10. A method for simulating thermal deformation of a superconducting cable under different laying channel conditions according to claim 9, wherein:
and obtaining the deformation and the deformation rate of each superconducting cable section based on the axial deformation of the copper cable.
Technical Field
The invention relates to the field of superconducting cables, in particular to a thermal deformation simulation method of a superconducting cable under different laying channel conditions.
Background
The application of superconducting technology in power systems is various, and is one of the main directions of research on superconducting application in recent years. Compared to power cables, superconducting cables have great advantages, such as: the power transmission capacity is strong, the cost is saved, the occupied space is small, the line impedance is extremely low, the power transmission loss is small, and the anti-magnetic interference capacity is strong; the method allows long-distance power transmission with relatively low voltage, and can also transmit power underground, thereby avoiding noise, electromagnetic pollution and potential safety hazard caused by ultrahigh-voltage high-altitude power transmission and protecting the ecological environment.
In the prior art, the superconducting cable is influenced by environmental factors such as a laying route, temperature, height difference and the like in a laying process, so that the superconducting cable is further deformed after being laid. Since such deformation may affect the precise laying of the cable to a certain extent, if the laying deformation can be accurately simulated and predicted before the superconducting cable is laid, the laying level of the superconducting cable can be effectively improved. However, the prior art does not provide a method for predicting the deformation of the superconducting cable.
Therefore, a simulation method for the laying of the superconducting cable is needed.
Disclosure of Invention
In order to solve the defects in the prior art, the invention aims to provide a thermal deformation simulation method of a superconducting cable under different laying channel conditions, which realizes the simulation calculation of the axial deformation result of the equivalent superconducting cable by segmenting, modeling and simulating the laid superconducting cable.
The invention adopts the following technical scheme.
A thermal deformation simulation method of a superconducting cable under different laying channel conditions comprises the following steps: step 1, collecting an engineering schematic diagram of the laying of the superconducting cable, and extracting a laying track diagram of the superconducting cable from the engineering schematic diagram; step 2, dividing the superconducting cable into superconducting cable sections based on the laying track diagram of the superconducting cable, and drawing a three-dimensional model for each superconducting cable section; and 3, adopting the copper material cable to approximate the equivalent superconducting cable, and obtaining the axial deformation result of the copper material cable based on the three-dimensional model simulation.
Preferably, the superconducting cable is a three-core superconducting cable, and each section of the superconducting cable is connected by a straight working well or a corner working well.
Preferably, a copper material cable with a diameter of 9mm is used to approximate a three-core superconducting cable with an equivalent weight of 15 t/km.
Preferably, the equivalent method of the copper material cable to approximate the equivalent superconducting cable is as follows: under the condition of the same temperature variation amplitude, the deformation of the copper material cable and the deformation of the superconducting cable are simulated or tested, and when the deformation of the copper material cable and the deformation of the superconducting cable are equal or similar, the copper material cable and the superconducting cable are approximately equivalent.
Preferably, the typical laying condition of the superconducting cable is modeled and simulated in advance, and the deformation amount and the equivalent stress of the superconducting cable under different typical laying conditions are obtained.
Preferably, the superconducting cables under different laying conditions are simulated by referring to the deformation amount and the equivalent stress of the superconducting cable.
Preferably, the laying condition of the superconducting cable includes: u-shaped horizontal laying, S-shaped horizontal laying and height difference laying.
Preferably, the deformation amount of the copper material cable includes a deformation amount in the X, Y, Z axis direction.
Preferably, the axial deformation amount of the copper material cable is calculated based on the deformation amount of the copper material cable in the X, Y, Z axial direction.
Preferably, the deformation amount and the deformation ratio of each superconducting cable segment are obtained based on the axial deformation amount of the copper material cable.
Compared with the prior art, the thermal deformation simulation method for the superconducting cable under different laying channel conditions can extract the laying track of the superconducting cable from the engineering schematic drawing for laying the superconducting cable, draw a three-dimensional model after segmenting the superconducting cable, perform equivalence on the superconducting cable, and approximately calculate the axial deformation result of the superconducting cable. The method can fully consider the influence of complex environmental factors on the superconducting cable in the laying process, and provides a simulation result with cable laying reference.
Compared with the prior art, the superconducting cable thermal deformation simulation method has the advantages that a better mode for coping with thermal expansion and contraction when the superconducting cable is laid is obtained through calculation of thermal expansion and contraction states and stress in different modes, and the superconducting cable thermal deformation simulation method is applied in engineering practice to solve the problem of thermal expansion and contraction of the superconducting cable in different temperature states such as normal temperature, low temperature and normal temperature. The method can be applied to various laying states such as arc, height difference and the like, can also be applied to laying positions of a working well, a pipe arrangement and the like, and has better applicability.
Drawings
FIG. 1 is a schematic flow chart illustrating steps of a thermal deformation simulation method for a superconducting cable under different laying channel conditions according to the present invention;
FIG. 2 is a diagram showing a laying trajectory of a superconducting cable in a thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention;
FIG. 3 is a schematic two-dimensional structure diagram of a superconducting cable segment in a thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention;
FIG. 4 is a schematic diagram showing the simulation result of X-axis deformation of a superconducting cable segment in the thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention;
FIG. 5 is a schematic diagram showing a simulation result of Y-axis deformation of a superconducting cable segment in the thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention;
fig. 6 is a schematic diagram of a simulation result of Z-axis deformation of a superconducting cable segment in the thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention.
Detailed Description
The present application is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present application is not limited thereby.
FIG. 1 is a schematic flow chart showing steps of a thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention. As shown in fig. 1, a thermal deformation simulation method for a superconducting cable under different laying channel conditions, wherein the method comprises the following steps: step 1, collecting an engineering schematic drawing for laying the superconducting cable, and extracting a laying track diagram of the superconducting cable from the engineering schematic drawing.
In the invention, because different conditions of the laying channels of the superconducting cables can affect the deformation of the superconducting cables to a certain extent, in order to prevent the operating condition of the superconducting cables from being affected by the thermal deformation and the mechanical stress deformation of the superconducting cables in the laying process, the deformation of the superconducting cables caused in the actual laying process needs to be simulated and estimated.
Specifically, in different superconducting cable laying environments, deformation behaviors of the superconducting cables have certain differences. Therefore, in an actual process, a layout of the superconducting cable may be obtained and processed. The superconducting cable of the engineering is laid between two 220KV substations, and power transmission between the two substations is realized. Between the two substations, the superconducting cable laid between the two substations can be laid in a conventional horizontal laying manner and a laying manner with a step difference according to the actual terrain.
Specifically, according to a straight working well or a corner working well through which the cable passes, the superconducting cable sections with different lengths can be connected end to end. After all the superconducting cable sections are connected, the total length of the whole superconducting cable section can be 1020 meters.
Fig. 2 is a diagram of a laying trajectory of a superconducting cable in the thermal deformation simulation method of the superconducting cable under different laying channel conditions according to the present invention. As shown in fig. 2, since the laying engineering drawing of the superconducting cable includes too many disordered contents, the engineering drawing must be simplified to perform analysis and calculation. According to the content in the engineering drawing, the surrounding environment information can be removed, and the installation track diagram of the primary superconducting cable can be extracted. The installation track map may include length and angle information of a straight work well and a corner work well connecting the sections, length information of a hole array pipe, and the like.
And 2, dividing the superconducting cable into superconducting cable sections based on the laying track diagram of the superconducting cable, and drawing a three-dimensional model for each superconducting cable section.
According to the corner working well or the straight working well, the superconducting cable can be divided into a plurality of different superconducting cable sections. In one embodiment of the present invention, the superconducting cable may be divided into 10 sections according to the numbering in fig. 2. Fig. 3 is a schematic two-dimensional structure diagram of a superconducting cable segment in the thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention. As shown in fig. 3, a two-dimensional schematic diagram of a segment of superconducting cable numbered 09 is shown. In this section, the row of holes is 66 meters long, the corner well is 14 meters long, and the total length of the superconducting cable is about 80 meters.
Preferably, the superconducting cable is a three-core superconducting cable, and each section of the superconducting cable is connected by a straight working well or a corner working well.
By the method, the related information of all superconducting cable segments can be recorded. Table 1 shows the information of the superconducting cable segment according to an embodiment of the present invention.
Numbering
Length of each segment/m
Total length/m
01
63+14
77
02
127+14
141
03
121+20
141
04
110+12
122
05
22+14
36
06
90+14
104
07
104+20
124
08
127+14
141
09
66+14
80
10
22+32
54
TABLE 1 superconducting Cable segmentation information
Through the length information and the corner information of the superconducting cable segments, each superconducting cable segment can be abstracted into a two-dimensional model. In addition, each superconducting cable segment is converted into a three-dimensional model according to other parameter information of the superconducting cable actually used, such as cross section diameter, unit length weight and the like.
And 3, adopting a copper material cable to approximate an equivalent superconducting cable, and obtaining an axial deformation result of the copper material cable based on three-dimensional model simulation.
In one embodiment of the present invention, the weight of the three-core superconducting cable used per kilometer may be about 15 tons, i.e., 147 newtons. Specifically, according to the previous modeling test, the three-core superconducting cable can be approximately equivalent to one copper cable.
Preferably, the equivalent method of the copper material cable to approximate the equivalent superconducting cable is as follows: under the condition of the same temperature variation amplitude, the deformation of the copper material cable and the deformation of the superconducting cable are simulated or tested, and when the deformation of the copper material cable and the deformation of the superconducting cable are equal or similar, the copper material cable and the superconducting cable are approximately equivalent.
Specifically, a plurality of different copper cables with the same length and different cross-sectional areas are simulated in sequence in a mode that the diameter of the cross section is from small to large or from large to small, and finally, the deformation of the superconducting cable and the deformation of the copper cable are most similar or even completely consistent on a certain cross-sectional area. At this time, the superconducting cable may be equivalent to the copper material cable. In one embodiment of the invention, a copper material cable with the diameter of 90mm is adopted to approximate a three-core superconducting cable with the equivalent weight of 15 t/km.
In order to further reduce the simulation calculation amount and improve the simulation speed and the simulation easiness, the actual model can be reduced in an equal proportion according to a certain proportion in the modeling process.
Preferably, the typical laying condition of the superconducting cable is modeled and simulated in advance, and the deformation amount and the equivalent stress of the superconducting cable under different typical laying conditions are obtained.
Specifically, in the present invention, the deformation amount and the equivalent stress of the superconducting cable of the complex structure under different shapes or under different stresses can be evaluated in advance in a plurality of different ways.
Preferably, the superconducting cables under different laying conditions are simulated by referring to the deformation amount and the equivalent stress of the superconducting cable.
Even under the condition that other conditions are completely the same, different laying modes still have serious influence on parameters such as the deformation amount and the equivalent stress of the superconducting cable, so a plurality of different typical cable laying modes are considered in the invention, and the equivalent stress and the deformation amount of the cable in different laying modes are subjected to simulation analysis. The simulation result of the invention can be better realized by acquiring the equivalent stress and deformation parameters of the cable in unit length in different laying modes.
Preferably, the laying condition of the superconducting cable includes: u-shaped horizontal laying, S-shaped horizontal laying and height difference laying.
For example, in the simulation process, the thermal expansion coefficient of the cable can be assumed to be 1.677 × 10-5℃-1The coefficient of friction between the cable and the gauntlet is 0.3. Under the above conditions, the simulation was performed on the U-shaped horizontally laid cable. The horizontal laying in the present invention is relative to the vertical laying which causes a step. In particular, the horizontal and differential elevations may be identical in the geometry, layout shape of the superconducting cable, but placed at the work wellThe manner of (c) is different. In order to simulate the situation that two ends of the cable stretch in the pipeline, the constraint condition can be set to include the condition 1: the movement of two horizontal sections of cables in the vertical direction; condition 2: the maximum displacement of the two sections of the cable in 3 directions. The constraint is carried out in such a way, so that the arrangement mode of the cable can be similar to the actual cable laying, and the influence caused by deformation and the cable displacement caused by deformation are maximally approximate to the actual situation.
Through cold-contraction deformation simulation, the deformation of the actual cable model under different spans can be obtained, as shown in table 2.
TABLE 2 cold shrinkage deformation and equivalent stress information table for U-shaped horizontal cabling
In the invention, the cables are horizontally laid, so that the U-shaped horizontally laid cables are basically not deformed in the vertical direction, namely the deformation in the Y direction does not need to be counted. The X-direction is parallel to the cable extension direction, and the Z-direction is perpendicular to the cable extension direction.
For cables spanning 1.05m, 1.35 and 1.65 in the X direction, the amount of deformation is small in the transverse direction and relatively large in the axial direction. According to the deformation of the cables with different lengths, the maximum equivalent stress at two ends of the cable is further known to be gradually reduced along with the increase of the length of the cable. The maximum equivalent stress value of a cable with a span of 1.05m is the largest.
In addition, the S-shaped horizontally laid structure may be regarded as a combination of two U-shaped laid structures. In the invention, the deformation in the Z direction and the deformation in the X direction and the equivalent stress condition can be respectively obtained by testing the superconducting cables with different amplitudes.
Different amplitude cable
0.525m*2
0.675m*2
0.825m*2
1.050m*2
In the Z direction
7.3384mm
7.4412mm
7.4984mm
7.545mm
In the X direction
18.5191mm
14.6302mm
12.106mm
9.7183mm
Maximum equivalent stress
2877.7MPa
2412.1MPa
1938MPa
1465.5MPa
TABLE 3S-TYPE HORIZONTAL CABLE COLD-RESTRACTION DEFORMATION AND EQUAL STRESS INFORMATION TABLE
Specifically, the amplitude of the cable as described herein refers to the axial length of the cable occupied by an S-shaped structure. With different amplitude, the amount of deformation of the cable is different. The cable with the smallest span has the largest value of the maximum equivalent stress. In addition, the span is two spans of 0.825m × 2 and 1.050m × 2, and the deformation amount of the cable can meet the requirement of cold contraction.
In addition, in the actual cable laying process, the cable is not only laid simply and horizontally, and when the condition of a cable laying channel is complex, the cable bears the influence of height difference. Therefore, according to the invention, two ends of the cable can be set to be in a free state in the simulation process aiming at the altitude difference laying mode, and the environmental constraint is not increased, so that the simulation result can be more accurate.
Particularly, the two ends of the cable can be restrained from displacing in the vertical direction, the friction coefficient between the cable and the pipe wall is designed to be 0.3, the friction force between the cable and the supporting bracket is ignored, the vertical bending amplitude is set in the work well for the cables in different height difference forms, the matching degree is calculated according to an actual cable model and a workstation by combining the condition of cable shrinkage, and simulation is carried out.
Typical laying pattern
Height difference 1.05m cable
Height difference 1.35m cable
Height difference 1.65m cable
In the X direction
3.386mm
3.7856mm
3.798mm
Y direction
7.4987mm
6.5889mm
5.5561mm
Maximum equivalent stress
1308.8MPa
743.72MPa
742MPa
Table 4 cold shrinkage deformation and equivalent stress information table for height difference cabling
Table 4 is a cold shrinkage deformation and equivalent stress information table of the elevation difference cabling of the present invention. As shown in table 4, at the cable intermediate working well with a height difference of 1.05m, the superconducting cable provides the largest amount of expansion and contraction for the entire cable.
Fig. 4 is a schematic diagram of a simulation result of X-axis deformation of a superconducting cable segment in a thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention. Fig. 5 is a schematic diagram of a simulation result of Y-axis deformation of a superconducting cable segment in the thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention. Fig. 6 is a schematic diagram of a simulation result of Z-axis deformation of a superconducting cable segment in the thermal deformation simulation method of a superconducting cable under different laying channel conditions according to the present invention. As shown in fig. 4 to 6, after the superconducting cable segment is equivalent to a copper cable, the deformation in each direction can be analyzed, and finally the total deformation is summarized.
In an embodiment of the present invention, simulation software may be used to simulate the three-dimensional model for laying the superconducting cable, and the result of the axial deformation amount is obtained, as shown in table 5. In table 5 of the present invention, l is an initial length of a superconducting cable segment, l' is an initial length of a laid superconducting cable segment, and l ″ is a length of a superconducting cable segment after thermal deformation.
Numbering
l/mm
l′/mm
l″/mm
01
77000
77852.17
77561.78
02
141000
141648.28
141151.09
03
141000
141648.28
141127.01
04
122000
122852.17
122377.96
05
36000
36852.17
36719.96
06
104000
104648.28
104268.14
07
124000
124648.28
124183.34
08
141000
141648.28
141111.43
09
80000
80852.17
80554.63
10
54000
54648.28
54458.85
TABLE 5 Length information of respective superconducting cable segments in different states
It can be seen that the length l ″ of the laying pattern after the thermal deformation is greater than the initial length l of the superconducting cable, and thus the laying scheme of the respective sections of the superconducting cable is feasible. The simulation analysis is carried out on the superconducting cable, the actual engineering situation is reflected more practically, and the simulation analysis method can be expanded and applied to similar situations and is beneficial to the implementation of other engineering cases.
Compared with the prior art, the thermal deformation simulation method for the superconducting cable under different laying channel conditions can extract the laying track of the superconducting cable from the engineering schematic drawing for laying the superconducting cable, draw a three-dimensional model after segmenting the superconducting cable, perform equivalence on the superconducting cable, and approximately calculate the axial deformation result of the superconducting cable. The method can fully consider the influence of complex environmental factors on the superconducting cable in the laying process, and provides a simulation result with cable laying reference.
The present applicant has described and illustrated embodiments of the present invention in detail with reference to the accompanying drawings, but it should be understood by those skilled in the art that the above embodiments are merely preferred embodiments of the present invention, and the detailed description is only for the purpose of helping the reader to better understand the spirit of the present invention, and not for limiting the scope of the present invention, and on the contrary, any improvement or modification made based on the spirit of the present invention should fall within the scope of the present invention.
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