CN102880747A - Method for modeling, calculating and analyzing temperature fields of photoelectric composite submarine cable - Google Patents

Abstract

The invention discloses a method for modeling, calculating and analyzing the temperature field of a photoelectric composite submarine cable. Input the material parameters of each component material into ANSYS finite element analysis software to establish the finite element model of the photoelectric composite submarine cable; Step 3: set the value range of the thermal load working current, ambient temperature and convective heat transfer coefficient of the photoelectric composite submarine cable; Step 4: Model the overall steady-state temperature field of the photoelectric composite submarine cable; Step 5: Model the local heating steady-state temperature field of the photoelectric composite submarine cable; Step 6: Model the transient temperature field of the photoelectric composite submarine cable for modeling. The present invention has extremely high accuracy in calculating the temperature field of the composite submarine cable under complex structures and environmental conditions; without a large amount of experimental data, the nonlinear mapping relationship between the conductor and optical fiber temperature of the photoelectric composite submarine cable can be obtained, which is simple and convenient .

Description

A Modeling Calculation and Analysis Method of Temperature Field of Photoelectric Composite Submarine Cable

technical field

The present invention relates to a distributed real-time monitoring and measurement technology for photoelectric composite submarine cables, in particular to a method for modeling, calculating and analyzing the temperature field of photoelectric composite submarine cables, specifically how to use the optical fiber temperature provided by Brillouin Optical Time Domain Analysis (BOTDA) equipment Data to obtain the method of the cable conductor temperature of the photoelectric composite submarine cable. the

Background technique

During the operation of the photoelectric composite submarine cable, thermal breakdown will be caused by factors such as the aging of the insulating layer, excessive power harmonics, poor intermediate joints, power supply voltage fluctuations, and heavy loads. Therefore, it is necessary to monitor the conductor temperature of the photoelectric composite submarine cable. However, since the photoelectric composite submarine cable is laid in the seabed, the temperature of the conductor cannot be directly measured. the

Contents of the invention

The purpose of the present invention is to provide a kind of photoelectric composite submarine cable temperature field modeling calculation analysis method, under the condition that the input parameter is accurate, the accuracy of calculating the temperature field of the composite submarine cable under complex structure and environmental conditions is extremely high, and needs A large amount of experimental data can be used to obtain the nonlinear mapping relationship between the cable conductor and the fiber temperature of the photoelectric composite submarine cable. Compared with the neural network method, it is undoubtedly much simpler and more convenient. the

In order to achieve the above object, the present invention is achieved through the following technical solutions:

A method for modeling, calculating and analyzing the temperature field of a photoelectric composite submarine cable, comprising the following steps:

Step 1: In the ANSYS finite element analysis software, establish the geometric model of the photoelectric composite submarine cable;

Step 2: Input the material parameters of each component material of the photoelectric composite submarine cable into ANSYS finite element analysis software to establish a finite element model of the photoelectric composite submarine cable;

Step 3: Set the thermal load working current, ambient temperature and convective heat transfer coefficient range of the photoelectric composite submarine cable;

Step 4: Model the overall steady-state temperature field of the optoelectronic composite submarine cable;

Step 5: Model the local heating steady-state temperature field of the optoelectronic composite submarine cable;

Step 6: Model the transient temperature field of the optoelectronic composite submarine cable.

The value range of the thermal load working current described in step 3 is [300, 400] A, the value range of the ambient temperature is [-31, 50] °C, and the value range of the convective heat transfer coefficient is [ 5, 1000] W/(m ² ·°C).

Described step 4 includes following sub-steps:

Step 4.1: meshing the geometric model of the photoelectric composite submarine cable described in step 1;

Step 4.2: According to the value range of the thermal load working current described in step 3, take a working current and input the thermal load of the heat generation rate;

Step 4.3: According to the value range of the ambient temperature described in step 3, set the ambient temperature of the boundary condition of the photoelectric composite submarine cable;

Step 4.4: According to the value range of the convective heat transfer coefficient described in step 3, set the boundary condition convective heat transfer coefficient of the photoelectric composite submarine cable;

Step 4.5: performing steady-state thermal analysis;

Step 4.6: Obtain the temperature of the optical fiber and conductor of the photoelectric composite submarine cable;

Step 4.7: Input the processed results into the database corresponding to the optical fiber temperature of the photoelectric composite submarine cable and the cable conductor temperature.

Described step 5 comprises following sub-steps:

Step 5.1: In ANSYS finite element analysis software, set the length of the photoelectric composite submarine cable according to the geometric model established by the physical structure dimension diagram of the photoelectric composite submarine cable described in step 1;

Step 5.2: According to the thermal conductivity coefficient of each component material of the photoelectric composite submarine cable obtained in step 2, take an insulating part of a length in the center of the photoelectric composite submarine cable, and set its thermal conductivity;

Step 5.3: meshing the geometric model of the photoelectric composite submarine cable with the length set in step 5.1;

Step 5.4: Repeat step 4.2, step 4.3, step 4.4, step 4.5, step 4.6 and step 4.7 of step 4 in sequence.

Described step 6 comprises following sub-steps:

Step 6.1: Repeat step 1;

Step 6.2: In the ANSYS finite element analysis software, input the material parameters of each component material of the photoelectric composite submarine cable;

Step 6.3: Repeat Step 4.1 and Step 4.2 in Step 4;

Step 6.4: According to the value range of the ambient temperature described in step 3, the ambient temperature of the boundary condition of the photoelectric composite submarine cable is taken;

Step 6.5: According to the value range of the convective heat transfer coefficient described in step 3, take the convective heat transfer coefficient of the boundary condition of the photoelectric composite submarine cable;

Step 6.6: Perform transient thermal analysis;

Step 6.7: Step 4.6 in Step 4;

Step 6.8: Obtain the time required to reach a steady state and the time required for the temperature of the optical fiber to change when the temperature of the conductor and optical fiber in the photoelectric composite submarine cable changes when the energized current changes.

Compared with the prior art, the present invention has the following advantages:

1. Under the condition of accurate input parameters, the accuracy of calculating the temperature field of the composite submarine cable under complex structure and environmental conditions is extremely high;

2. Compared with the neural network method that requires a large amount of experimental data to obtain the nonlinear mapping relationship between the cable conductor and the fiber temperature of the photoelectric composite submarine cable, it is very simple and convenient.

Description of drawings

Fig. 1 is a schematic diagram of the submarine cable structure of a method for modeling, calculating and analyzing the temperature field of a photoelectric composite submarine cable according to the present invention. the

Detailed ways

The present invention will be further elaborated below by describing a preferred specific embodiment in detail in conjunction with the accompanying drawings. the

A method for modeling, calculating and analyzing the temperature field of a photoelectric composite submarine cable, comprising the following steps:

Step 1: Obtain the physical structure size drawing of the photoelectric composite submarine cable 1, and establish its geometric model. In the ANSYS finite element analysis software, according to the physical structure size diagram of the photoelectric composite submarine cable, its geometric model is established. In this embodiment, a schematic structural diagram of a submarine cable modeled as HYJQ41-26/35KV-3*185+SM3*10C is shown in FIG. 1 .

Step 2: Obtain the material parameters of each component material of the optoelectronic composite submarine cable through an external Brillouin optical time domain analysis (BOTDA) device. In this embodiment, the material parameters include: density, specific heat capacity, and thermal conductivity. Establish Finite element model of optoelectronic composite submarine cable 1. the

Step 3: List the ranges of thermal load operating current I, ambient temperature T, and convective heat transfer coefficient H. In this embodiment, set: the value range of thermal load operating current I is [300, 400]A, and the ambient temperature The value range of T is [-31, 50]°C, and the value range of the convective heat transfer coefficient H is [5, 1000]W/(m ² ·°C).

Step 4: Model the overall steady-state temperature field of the optoelectronic composite submarine cable 1. The overall steady-state temperature field modeling includes the following sub-steps:

Step 4.1: Perform grid division on the geometric model of the optical-electrical composite submarine cable 1 described in step 1.

Step 4.2: Take the working current I as 300A, and input the thermal load of the heat generation rate according to the heat generation rate Q=I ² R/(LS), wherein, R is the resistance of the conductor 14 of the photoelectric composite submarine cable 1, and L is the photoelectric composite cable 1 The length of the submarine cable 1, S is the cross-sectional area of the conductor 14 of the photoelectric composite submarine cable 1; in the present embodiment, the conductor of the submarine cable whose model is HYJQ41-26/35KV-3*185+SM3*10C is a copper core .

Step 4.3: Set the first temperature boundary condition of the photoelectric composite submarine cable 1: the ambient temperature is -31°C. the

Step 4.4: Set the boundary condition of the first convective heat transfer coefficient of the photoelectric composite submarine cable 1: the convective heat transfer coefficient is 5W/(m ² ·°C).

Step 4.5: Perform steady-state thermal analysis. the

Step 4.6: Perform post-processing on the calculated results to obtain the temperature of the optical fiber 12 and the temperature of the conductor 14 of the photoelectric composite submarine cable 1 . the

Step 4.7: Input the processed results into the corresponding database of the temperature of the optical fiber 12 of the photoelectric composite submarine cable 1 and the temperature of the conductor 14. This database is used in the online monitoring system of the photoelectric composite submarine cable. According to the temperature of the optical fiber 12 obtained by the BOTDA equipment data, look up the table and display the temperature of the conductor 14 of the photoelectric composite cable 1 . the

Step 5: Model the local heating steady-state temperature field of the optoelectronic composite submarine cable 1. The local heating steady-state temperature field modeling includes the following sub-steps:

Step 5.1: In the ANSYS finite element analysis software, according to the geometric model established by the physical structure size diagram of the photoelectric composite submarine cable 1 described in step 1, in the present embodiment, the length L of the photoelectric composite submarine cable 1 is set as 10.1 meters, it is convenient to take the insulating part with a length of 0.1m at the middle 5m~5.1m of the photoelectric composite submarine cable 1, so as to modify its thermal conductivity.

Step 5.2: According to the thermal conductivity coefficient of each component material of the photoelectric composite submarine cable 1 obtained in step 2, take the insulating part 11 with a length of 0.1 meters in the center of the photoelectric composite submarine cable 1, and the insulating part 11 is as shown in Figure 1. Set Its thermal conductivity is 0.001W/(m·℃), which makes it much smaller than the thermal conductivity of the insulating material itself, so as to obtain the material characteristics in its heating state. the

Step 5.3: The geometric model of the optical-electrical composite submarine cable 1 with a length of 10.1 meters described in step 5.1 is meshed. the

Step 5.4: Repeat Step 4.2, Step 4.3, Step 4.4, Step 4.5, Step 4.6, and Step 4.7 of Step 4 in sequence. the

Step 6: Model the transient temperature field of the optoelectronic composite submarine cable 1. To change the energizing current of the photoelectric composite submarine cable 1 from 0 to 300A, the transient temperature field modeling includes the following sub-steps:

Step 6.1: Repeat step 1.

Step 6.2: In the ANSYS finite element analysis software, input the material parameters of each component material of the optoelectronic composite submarine cable 1. In this embodiment, the material parameters include: density, specific heat capacity, and thermal conductivity. the

Step 6.3: Repeat Step 4.1, Step 4.2 in Step 4. the

Step 6.4: Take the second temperature boundary condition of the photoelectric composite submarine cable 1 as: ambient temperature 20°C. the

Step 6.5: Take the boundary condition of the second convective heat transfer coefficient of the photoelectric composite submarine cable 1 as: convective heat transfer coefficient 8W/(m ² ·°C).

Step 6.6: Change the energizing current of the photoelectric composite submarine cable 1 from 0 to 300A, and perform transient thermal analysis. the

Step 6.7: Step 4.6 in Step 4. the

Step 6.8: Obtain the temperature of the conductor 14 and the optical fiber 12 in the photoelectric composite submarine cable 1 when the energized current changes: ①The temperature of the conductor 14 and the temperature of the optical fiber 12 no longer rise, and the time required to reach a stable state; ②The optical fiber 12 The time required for the temperature to change. the

In this embodiment, the temperature and time data obtained in steps 5 and 6 are used to judge the temperature data of the optical fiber 12 obtained by BOTDA when the photoelectric composite submarine cable 1 is abnormal. in what operating state. the

In summary, the present invention is a method for modeling, calculating and analyzing the temperature field of a photoelectric composite submarine cable. Under the condition of accurate input parameters, the accuracy of calculating the temperature field of a composite submarine cable under complex structures and environmental conditions is extremely high. Compared with the neural network method that requires a large amount of experimental data to obtain the nonlinear mapping relationship between the cable conductor and the fiber temperature of the optoelectronic composite submarine cable, it is undoubtedly much simpler and more convenient. the

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended claims. the

Claims (5)

1. a photoelectric composite sea cable temperature field Modeling Calculation analytical approach is characterized in that, comprises following steps:

Step 1: in the ANSYS finite element analysis software, set up the geometric model of photoelectric composite sea cable;

Step 2: with the material parameter input ANSYS finite element analysis software of each composition material of photoelectric composite sea cable, set up the finite element model of photoelectric composite sea cable;

Step 3: the span of setting thermal force working current, environment temperature and the convection transfer rate of photoelectric composite sea cable;

Step 4: the whole Steady-State Thermal Field to photoelectric composite sea cable carries out modeling;

Step 5: the local pyrexia Steady-State Thermal Field to photoelectric composite sea cable carries out modeling;

Step 6: the transient state temperature field to photoelectric composite sea cable carries out modeling.

2. photoelectric composite sea cable as claimed in claim 1 temperature field Modeling Calculation analytical approach, it is characterized in that, the span of the thermal force working current described in the described step 3 is [300,400] A, the span of environment temperature is [31,50] ℃, the span of convection transfer rate is [5,1000] W/ (m ²℃).

3. photoelectric composite sea cable as claimed in claim 2 temperature field Modeling Calculation analytical approach is characterized in that, described step 4 comprises following substep:

Step 4.1: the geometric model of the photoelectric composite sea cable described in the step 1 is carried out grid divide;

Step 4.2: according to the span of the thermal force working current described in the step 3, get a working current, input heat generation rate thermal force;

Step 4.3: according to the span of the environment temperature described in the step 3, set the boundary condition environment temperature of photoelectric composite sea cable;

Step 4.4: according to the span of the convection transfer rate described in the step 3, set the boundary condition convection transfer rate of photoelectric composite sea cable;

Step 4.5: carry out steady-state thermal analysis;

Step 4.6: the temperature of obtaining optical fiber and the conductor of photoelectric composite sea cable;

Step 4.7: will process in acquired results input photoelectric composite sea cable fiber optic temperature and the cable conductor temperature correspondence database.

4. photoelectric composite sea cable as claimed in claim 3 temperature field Modeling Calculation analytical approach is characterized in that, described step 5 comprises following substep:

Step 5.1: in the ANSYS finite element analysis software, according to the geometric model that the physical arrangement dimensional drawing of the photoelectric composite sea cable described in the step 1 is set up, set the length of photoelectric composite sea cable;

Step 5.2: according to the heat-conduction coefficient of each composition material of photoelectric composite sea cable that obtains in the step 2, get the insulated part of center one segment length of photoelectric composite sea cable, set its heat-conduction coefficient;

Step 5.3: the geometric model of the photoelectric composite sea cable of the length that sets in the step 5.1 carries out grid and divides;

Step 5.4: the step 4.2, step 4.3, step 4.4, step 4.5, step 4.6, the step 4.7 that repeat successively described step 4.

5. photoelectric composite sea cable as claimed in claim 4 temperature field Modeling Calculation analytical approach is characterized in that, described step 6 comprises following substep:

Step 6.1: repeating step 1;

Step 6.2: in the ANSYS finite element analysis software, the material parameter of each composition material of input photoelectric composite sea cable;

Step 6.3: step 4.1, step 4.2 in the repeating step 4;

Step 6.4: according to the span of the environment temperature described in the step 3, get the boundary condition environment temperature of photoelectric composite sea cable;

Step 6.5: according to the span of the convection transfer rate described in the step 3, get the boundary condition convection transfer rate of photoelectric composite sea cable;

Step 6.6: carry out Transient Thermal Analysis;

Step 6.7: the step 4.6 in the step 4;

Step 6.8: obtain conductor and fiber optic temperature in the photoelectric composite sea cable when electrical current changes: reach required time of steady state (SS) and fiber optic temperature and change the required time.

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