CN117168639A - Cable temperature field distribution measuring device, method and equipment - Google Patents
Cable temperature field distribution measuring device, method and equipment Download PDFInfo
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Abstract
The application discloses a cable temperature field distribution measuring device, a method and equipment, wherein the device comprises a cable, a plurality of temperature sensor groups, a retarding layer, a temperature acquisition mechanism and a computing unit; the blocking layer is sleeved on the cable; each temperature sensor group is connected with the cable through an embedded retarding layer and is respectively and equidistantly arranged at the first end and the second end of the cable; each temperature sensor group is connected with the temperature acquisition mechanism; the temperature acquisition mechanism is in communication connection with the computing unit; acquiring a plurality of temperature data through a temperature sensor group, and transmitting the temperature data to a temperature acquisition mechanism; the temperature acquisition mechanism is used for transmitting the received plurality of temperature data to the calculation unit; the computing unit is used for determining cable temperature field distribution based on the plurality of temperature data. The technical problem that in the prior art, the result can be obtained only by carrying out simulation calculation on each joint, so that the calculated amount of a cable temperature field is overlarge is solved.
Description
Technical Field
The present application relates to the field of power cable temperature calculation technologies, and in particular, to a cable temperature field distribution measurement apparatus, method, and device.
Background
With the development of the economic and power industries in China, an underground cable system of an urban power distribution network has become an important part in the power grid transformation engineering in China, so that accurate calculation and timely early warning of the temperature rise of the power cable are of great significance for safe operation of the power system. Compared with the cable body, the cable connector has a complex structure, the field installation process is not proper, and the possibility of overheat faults caused by the existence of contact resistance is increased, so that the normal operation of the cable is affected to a certain extent.
The cable is commonly used for a low-voltage distribution line in a three-phase alternating current power grid and a three-phase four-wire system with a neutral point grounded, but the insulation ageing of a cable joint can be accelerated under a high-temperature environment after long-term operation, so that the normal operation of the cable joint is influenced. Therefore, the distribution of the temperature field of the cable joint is required to be accurately calculated, the temperature development rule of the cable joint is mastered, the timely early warning of the overhigh temperature rise is realized, and safety accidents such as overheat faults and even fire disasters are avoided.
In the prior art, most of the modeling calculation is performed on the temperature field of the cable based on a finite element simulation analysis method, but because one power cable is distributed with more than one cable joint in the whole length, the working condition of each joint is different, and the result can be obtained only by performing simulation calculation on each joint, so that the calculation amount of the temperature field of the cable is overlarge.
Disclosure of Invention
The application provides a cable temperature field distribution measuring device, method and equipment, which solve the technical problems that the calculation amount of a cable temperature field is overlarge because the temperature field of a crosslinked polyethylene insulated cable is calculated mostly based on a finite element analysis method and each joint is required to be subjected to simulation calculation to obtain a result in the prior art.
The first aspect of the application provides a cable temperature field distribution measuring device, which comprises a cable, a plurality of temperature sensor groups, a retarding layer, a temperature acquisition mechanism and a calculation unit;
the blocking layer is sleeved on the cable;
each temperature sensor group is connected with the cable through embedding the blocking layer and is respectively and equidistantly arranged at the first end and the second end of the cable;
each temperature sensor group is connected with the temperature acquisition mechanism;
the temperature acquisition mechanism is in communication connection with the computing unit;
the temperature sensor group is used for acquiring temperature data corresponding to the first end of the cable and the second end of the cable and transmitting the temperature data to the temperature acquisition mechanism;
the temperature acquisition mechanism is used for receiving the temperature data transmitted by each temperature sensor group and sending the temperature data to the calculation unit;
the computing unit is used for acquiring and determining temperature field distribution corresponding to the cable based on the plurality of temperature data.
Optionally, the temperature sensor group comprises a first temperature sensor, a heat conducting layer and a second temperature sensor which are sequentially arranged;
the first temperature sensor and the second temperature sensor are connected with the temperature acquisition mechanism;
the first temperature sensor is used for acquiring upper temperature data corresponding to the first end of the cable and the second end of the cable and transmitting the upper temperature data to the temperature acquisition mechanism;
the second temperature sensor is used for acquiring lower-layer temperature data corresponding to the first end of the cable and the second end of the cable, and transmitting the lower-layer temperature data to the temperature acquisition mechanism.
Optionally, the computing unit is specifically configured to:
substituting each upper layer temperature data and corresponding lower layer temperature data into a preset first formula respectively to determine a plurality of heat conduction rates, wherein the plurality of heat conduction rates comprise a first heat conduction rate of each temperature sensor group corresponding to a first end of the cable and a second heat conduction rate of each temperature sensor group corresponding to a second end of the cable;
substituting each first heat conduction rate and each second heat conduction rate into a preset second formula respectively to determine a first heat flux corresponding to the first end of the cable and a second heat flux sum corresponding to the second end of the cable;
performing difference operation on the first heat flux sum and the second heat flux sum to determine the heat flux difference of the actual working condition;
calculating the hot spot contact resistance of the actual working condition by adopting a preset experiment heat dissipation capacity ratio and the actual working condition heat flux difference;
and determining the temperature field distribution corresponding to the cable based on the hot spot contact resistance under the actual working condition.
Optionally, the preset first formula specifically includes:
in which Q sn A heat transfer rate for an nth temperature sensor group; k is the thermal conductivity of the heat conducting part of the retarding layer; s is the contact area between the temperature sensor and the retarding layer;is the rate of change of temperature; t (T) sn1 Is lower layer temperature data; t (T) sn2 Is upper layer temperature data; h is the thickness of the retarding layer;
the preset second formula specifically comprises the following steps:
in which Q w1 Is a first heat flux sum; q (Q) w2 Is the second heat flux sum; d is the cable diameter; l is the side length of the temperature sensor; q (Q) sn1 A first heat transfer rate for an nth temperature sensor group corresponding to the first end of the cable; s is S c S is the contact area of the temperature sensor and the cable c =L 2 ;Q sn2 A second heat transfer rate for an nth temperature sensor group corresponding to the second end of the cable.
Optionally, the thermal conductivity of the thermally conductive layer is higher than the thermal conductivity of the retarding layer.
The second aspect of the application provides a cable temperature field distribution measurement method, comprising the following steps:
acquiring a plurality of temperature data corresponding to a cable first end and a cable second end of a cable, wherein the temperature data comprise upper-layer temperature data and lower-layer temperature data;
each upper layer temperature data and corresponding lower layer temperature data are adopted and respectively substituted into a preset first formula to determine a plurality of heat conduction rates;
and determining a temperature field distribution corresponding to the cable based on a plurality of the heat conduction rates.
Optionally, the plurality of heat conduction rates include a first heat conduction rate of each temperature sensor group corresponding to the first end of the cable and a second heat conduction rate of each temperature sensor group corresponding to the second end of the cable; the step of determining a temperature field distribution corresponding to the cable based on a plurality of the heat conduction rates includes:
substituting each first heat conduction rate and each second heat conduction rate into a preset second formula respectively to determine a first heat flux corresponding to the first end of the cable and a second heat flux sum corresponding to the second end of the cable;
performing difference operation on the first heat flux sum and the second heat flux sum to determine the heat flux difference of the actual working condition;
calculating the hot spot contact resistance of the actual working condition by adopting a preset experiment heat dissipation capacity ratio and the actual working condition heat flux difference;
and determining the temperature field distribution corresponding to the cable based on the hot spot contact resistance under the actual working condition.
Optionally, the preset first formula specifically includes:
in which Q sn A heat transfer rate for an nth temperature sensor group; k is the thermal conductivity of the heat conducting part of the retarding layer; s is the contact area between the temperature sensor and the retarding layer;is the rate of change of temperature; t (T) sn1 Is lower layer temperature data; t (T) sn2 Is upper layer temperature data; h is the blocking layer thickness.
Optionally, the preset second formula is specifically:
in which Q w1 Is a first heat flux sum; q (Q) w2 Is the second heat flux sum; d is the cable diameter; l is the side length of the temperature sensor; q (Q) sn1 A first heat transfer rate for an nth temperature sensor group corresponding to the first end of the cable; s is S c S is the contact area of the temperature sensor and the cable c =L 2 ;Q sn2 A second heat transfer rate for an nth temperature sensor group corresponding to the second end of the cable.
An electronic device according to a third aspect of the present application includes a memory and a processor, where the memory stores a computer program, and the computer program when executed by the processor causes the processor to execute the steps of the cable temperature field distribution measurement method according to any one of the above.
From the above technical scheme, the application has the following advantages:
the first aspect of the present application provides a cable temperature field distribution measurement device, which includes a cable, a plurality of temperature sensor groups, a retardation layer, a temperature acquisition mechanism and a calculation unit; the temperature sensor groups are respectively arranged at the first end and the second end of the cable at equal intervals, are connected with the temperature acquisition mechanism, and are in communication connection with the calculation unit; firstly, acquiring temperature data corresponding to a first end and a second end of a cable through a temperature sensor group, and transmitting the temperature data to a temperature acquisition mechanism; the temperature acquisition mechanism transmits the temperature data transmitted by each temperature sensor group to the calculation unit; finally, determining the temperature field distribution corresponding to the cable according to the plurality of temperature data by a computing unit; above-mentioned scheme is through locating the heat exchange between separation cable that will block layer cover cable and the air that can be fine to improve temperature data's collection precision, simultaneously, through a plurality of temperature data that the computing element gathered according to a plurality of temperature sensor group that set up at cable first end and second end, confirm the temperature field distribution that the cable corresponds, this process need not to establish corresponding model and carry out simulation calculation to the cable, can significantly reduce the calculated amount of cable temperature field, thereby improve cable temperature field's computational efficiency.
The second aspect of the above technical solution of the present application provides a method for measuring a cable temperature field distribution, which includes firstly obtaining a plurality of temperature data corresponding to a first end of a cable and a second end of the cable, wherein the temperature data includes upper layer temperature data and lower layer temperature data, then substituting each upper layer temperature data and corresponding lower layer temperature data into a preset first formula respectively to determine a plurality of heat conduction rates, and finally determining a temperature field distribution corresponding to the cable based on the plurality of heat conduction rates; according to the scheme, the acquired upper temperature data and lower temperature data corresponding to the first end and the second end of the cable are subjected to algorithm operation, so that the temperature field distribution process corresponding to the cable is determined, and compared with the existing process of modeling and calculating the temperature field of the cable based on a finite element simulation analysis method, the process that the temperature field distribution result can be obtained only by carrying out simulation calculation on each joint can greatly reduce the calculation amount of the temperature field of the cable, and the calculation efficiency of the temperature field of the cable is improved.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the application, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a cable temperature field distribution measuring device according to a first embodiment of the present application;
fig. 2 is a schematic structural diagram of a blocking layer sleeved on a cable according to a first embodiment of the present application;
FIG. 3 is a simplified equivalent model of a power cable joint and the vicinity of the joint according to an embodiment of the present application;
FIG. 4 illustrates a cable hot spot heat dissipation path provided in accordance with a first embodiment of the present application;
fig. 5 is a flowchart illustrating steps of a cable temperature field distribution measurement method according to a second embodiment of the present application.
Wherein the reference numerals have the following meanings:
1. a temperature acquisition mechanism; 2. a cable; 3. a first temperature sensor; 4. a heat conducting layer; 5. a second temperature sensor; 6. a retarder layer.
Detailed Description
The embodiment of the application provides a cable temperature field distribution measuring device, method and equipment, which are used for solving the technical problem that the calculation amount of a cable temperature field is overlarge because the temperature field of a crosslinked polyethylene insulated cable is calculated mostly based on a finite element analysis method and each connector is required to be subjected to simulation calculation to obtain a result.
In order to make the objects, features and advantages of the present application more comprehensible, the technical solutions in the embodiments of the present application are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Referring to fig. 1-2, fig. 1 is a schematic structural diagram of a cable temperature field distribution measuring device according to an embodiment of the application.
The application provides a cable temperature field distribution measuring device which comprises a cable 2, a plurality of temperature sensor groups, a retarding layer 6, a temperature acquisition mechanism 1 and a calculating unit, wherein the retarding layer is arranged on the cable; the blocking layer 6 is sleeved on the cable 2; each temperature sensor group is connected with the cable 2 through an embedded retarding layer 6 and is respectively and equidistantly arranged at the first end and the second end of the cable 2; each temperature sensor group is connected with the temperature acquisition mechanism 1; the temperature acquisition mechanism 1 is in communication connection with the computing unit; the temperature sensor group is used for acquiring temperature data corresponding to the first end and the second end of the cable and transmitting the temperature data to the temperature acquisition mechanism 1; the temperature acquisition mechanism 1 is used for receiving the temperature data transmitted by each temperature sensor group and sending the temperature data to the calculation unit; the computing unit is used for acquiring and determining temperature field distribution corresponding to the cable based on the plurality of temperature data.
The first end of the cable is a location for deploying the temperature sensor set proximate the cable junction.
The second end of the cable is a position of disposing the temperature sensor group at a cable body far away from the cable joint.
It should be noted that, locate the cable 2 with blocking layer 6 cover, each temperature sensor group is connected with cable 2 through embedding blocking layer 6, deploys the surface at the cable to the equidistant cable first end and the cable second end that set up at cable 2 respectively, wherein, still need accord with the deployment principle on deployment temperature sensor group and the cable, specifically do: of a plurality of temperature sensor groups arranged close to the cable joint, the second temperature sensor of the two temperature sensor groups furthest away from the cable joint has the same acquired temperature, namely T S6 lower =T S7 under .T S6 lower ≠T S5 lower 。
In this embodiment, the temperature acquisition mechanism 1 may take various forms, for example, a DSP core, an ARM core, and other single-chip computers or acquisition cards, FPGAs, etc. that cooperate with the a/D sampling circuit to perform sampling; the retarding layer is of an annular structure, is convenient to nest on the cable, the retarding layer main body can be filled with foaming polyurethane or aerogel with low heat conductivity, the environment around the temperature measuring point on the surface of the cable is isolated through the retarding layer, and heat exchange between the cable and air can be well blocked, so that the acquisition accuracy of temperature data is improved, and obvious temperature difference can occur in the temperature data acquired by the temperature sensor group under the condition of cable working condition load.
Further, the occurrence of hot spots in the power cable typically occurs at the junction or intermediate junction, because the cables are connected by the junction or intermediate junction, transferring energy from one cable to another, the current being converted and connected, causing heat generation, and the current density at the junction or intermediate junction being higher, thus causing a local temperature rise; secondly, the problems of incomplete cable connection, poor contact, insulation damage and the like exist at the joint or the middle joint, and in the operation process of the power system, the connection at the joint can be loose, oxidized or corroded and the like under the influence of factors such as temperature change, mechanical vibration, humidity and the like, so that contact resistance and local hot spots can be generated when current passes through the joint or the middle joint; in addition, there are often high electric fields and voltage gradients at the joint or the middle joint, when the power cable transmits electric energy, the electric fields and the voltage gradients are generated, and the electric fields and the voltage gradients at the joint may be increased due to the geometric structure change of the cable, the non-uniform medium characteristics and other reasons, so that local hot spots are caused to form.
Further, referring to fig. 4, the surrounding structure of the power cable in fig. 3 is a simplified structure, the actual surrounding structure of the power cable has several layers, but the layering of the structure does not affect the process of calculating the temperature field distribution of the cable in the present application, in actual operation, the heat source of the power cable comes from the heat generated by the conductor resistor under the action of current, and the heat generated by the power cable comes from two parts, one is the heat generated by the cable conductor under the action of current, and the second is the heat generated by the resistor at the conductor crimping position under the action of current, because the resistance at the crimping position is generally significantly larger and the temperature is higher, so the power cable is called a hot spot; the heat generated by the hot spot is dissipated through a heat dissipation path as shown in fig. 4.
As a further improvement, the temperature sensor group comprises a first temperature sensor 3, a heat conducting layer 4 and a second temperature sensor 5 which are arranged in sequence; the first temperature sensor 3 and the second temperature sensor 5 are connected with the temperature acquisition mechanism 1; the first temperature sensor 3 is used for acquiring upper temperature data corresponding to the first end and the second end of the cable and transmitting the upper temperature data to the temperature acquisition mechanism 1; the second temperature sensor 5 is used for acquiring lower-layer temperature data corresponding to the first end and the second end of the cable, and transmitting the lower-layer temperature data to the temperature acquisition mechanism 1.
Optionally, the thermal conductivity of the thermally conductive layer 4 is higher than the thermal conductivity of the retarding layer 6.
It should be noted that, each temperature sensor group includes a first temperature sensor 3 and a second temperature sensor 5, upper layer temperature data of each cable position is collected by each first temperature sensor 3, and lower layer temperature data of each cable position is collected by each second temperature sensor 5, and then collected to the temperature collection mechanism 1, the appearance of each first temperature sensor 3 and each second temperature sensor 5 is a square temperature sensor, and the contact areas of each first temperature sensor 3 and each second temperature sensor 5 with the blocking layer 6 and the cable 2 are kept consistent, so that heat flow calculation is performed on the collected upper layer temperature data and lower layer temperature data; wherein, the contact area of the first temperature sensor 3 and the second temperature sensor 5 with the blocking layer is set as S, the contact area with the cable is set as Sc, the setting distance between the temperature sensors is set as an integral multiple of S, sc=L 2 L is the side length of the temperature sensor,
further, the heat conducting layer 4 can be processed by selecting materials with proper heat conductivity according to different cable voltage grades, and the selection principle is that the heat conductivity is higher than that of materials adopted by the retarding layer, such as solid ceramics, and the like, under the condition of the working condition of the cable, obvious temperature difference can occur between the upper sensor and the lower sensor.
As a further refinement, the computing unit is specifically configured to: substituting each upper layer temperature data and the corresponding lower layer temperature data into a preset first formula respectively to determine a plurality of heat conduction rates, wherein the plurality of heat conduction rates comprise a first heat conduction rate of each temperature sensor group corresponding to a first end of the cable and a second heat conduction rate of each temperature sensor group corresponding to a second end of the cable; substituting each first heat conduction rate and each second heat conduction rate into a preset second formula respectively, and determining a first heat flux sum corresponding to the first end of the cable and a second heat flux sum corresponding to the second end of the cable; performing difference operation on the first heat flux sum and the second heat flux sum, and determining the heat flux difference of the actual working condition; calculating the hot spot contact resistance of the actual working condition by adopting a preset experiment heat dissipation capacity ratio and the heat flux difference of the actual working condition; and determining the temperature field distribution corresponding to the cable based on the hot spot contact resistance under the actual working condition.
The preset first formula specifically comprises the following steps:
in which Q sn A heat transfer rate for an nth temperature sensor group; k is the thermal conductivity of the heat conducting part of the retarding layer; s is the contact area between the temperature sensor and the retarding layer;is the rate of change of temperature; t (T) sn1 Is lower layer temperature data; t (T) sn2 Is upper layer temperature data; h is the thickness of the retarding layer;
the preset second formula specifically comprises the following steps:
in which Q w1 Is a first heat flux sum; q (Q) w2 Is the second heat flux sum; d is the cable diameter; l is the side length of the temperature sensor; q (Q) sn1 A first heat transfer rate for an nth temperature sensor group corresponding to the first end of the cable; s is S c S is the contact area of the temperature sensor and the cable s =L 2 ;Q sn2 A second heat transfer rate for an nth temperature sensor group corresponding to the second end of the cable.
The heat conduction rate comprises a first heat conduction rate of each temperature sensor group corresponding to the first end of the cable and a second heat conduction rate of each temperature sensor group corresponding to the second end of the cable
It should be noted that, according to the fourier heat conduction law, the heat conduction rate is proportional to the heat transfer area and the temperature gradient, and inversely proportional to the thermal conductivity of the object, the dissipation outwards through the cable joint structure and the dissipation through the conductor towards the cable body and the cable surrounding structure are distributed in proportion, after the cable joint and the cable structure are determined, they do not change with the change of the temperature compliance, so a preset experimental dissipation heat ratio η is set, which represents the proportion of the heat dissipated by the hot spot temperature along the conductor towards the cable body and through the surrounding structure to the total heat.
Further, firstly, building an experiment platform according to a cable of an actual working condition to be measured, and measuring an experiment hot spot contact resistance R 1 And experimental heat flux difference Q t1 Since the power system is monitored by load, the through current I is a known value, and the experimental hot spot contact resistance R is adopted 1 And calculating the experimental hot spot thermal power Q through the flow I 1 The method specifically comprises the following steps: q (Q) 1 =I 2 ×R 1 The method comprises the steps of carrying out a first treatment on the surface of the Then using the measured experimental heat flux difference Q t1 And experimental hot spot thermal power Q 1 The heat dissipation capacity ratio eta of the preset experiment is calculated, and the specific steps are as follows: η=q t1 /Q 1 The method comprises the steps of carrying out a first treatment on the surface of the After determining the preset experiment heat dissipation capacity ratio eta, when a technician needs to calculate the temperature field distribution under the actual working condition of the cable, the temperature field distribution is input into a calculation unit, and the actual working condition heat flux difference Q obtained by the calculation unit according to each upper layer temperature data and the corresponding lower layer temperature data is combined t The actual working condition hot spot thermal power Q and the actual working condition hot spot contact resistance R are obtained, and the actual working condition hot spot thermal power Q and the actual working condition hot spot contact resistance R are specifically as follows: q=q t /η,R=Q/I 2 The method comprises the steps of carrying out a first treatment on the surface of the And finally, determining the temperature field distribution corresponding to the cable based on the hot spot contact resistance R in the actual working condition, and then evaluating the current carrying capacity of the cable line according to the result displayed by the temperature field distribution.
In the embodiment of the application, the application provides a cable temperature field distribution measuring device, which comprises a cable, a plurality of temperature sensor groups, a retarding layer, a temperature acquisition mechanism and a computing unit; the temperature sensor groups are respectively arranged at the first end and the second end of the cable at equal intervals, are connected with the temperature acquisition mechanism, and are in communication connection with the calculation unit; firstly, acquiring temperature data corresponding to a first end and a second end of a cable through a temperature sensor group, and transmitting the temperature data to a temperature acquisition mechanism; the temperature acquisition mechanism transmits the temperature data transmitted by each temperature sensor group to the calculation unit; finally, determining the temperature field distribution corresponding to the cable according to the plurality of temperature data by a computing unit; above-mentioned scheme is through locating the heat exchange between separation cable that will block layer cover cable and the air that can be fine to improve temperature data's collection precision, simultaneously, through a plurality of temperature data that the computing element gathered according to a plurality of temperature sensor group that set up at cable first end and second end, confirm the temperature field distribution that the cable corresponds, this process need not to establish corresponding model and carry out simulation calculation to the cable, can significantly reduce the calculated amount of cable temperature field, thereby improve cable temperature field's computational efficiency.
Referring to fig. 5, fig. 5 is a diagram illustrating a cable temperature field distribution measurement method according to a second embodiment of the present application.
The application provides a cable temperature field distribution measuring method, which comprises the following steps:
step 501, a plurality of temperature data corresponding to a first end of a cable and a second end of the cable are obtained, wherein the temperature data comprises upper layer temperature data and lower layer temperature data.
In this embodiment, a plurality of temperature data corresponding to a first end of a cable and a second end of the cable are obtained, where the temperature data includes upper layer temperature data and lower layer temperature data.
Step 502, each upper layer temperature data and the corresponding lower layer temperature data are adopted to be respectively substituted into a preset first formula, and a plurality of heat conduction rates are determined.
Optionally, the preset first formula is specifically:
in which Q sn A heat transfer rate for an nth temperature sensor group; k is the thermal conductivity of the heat conducting part of the retarding layer; s is the contact area between the temperature sensor and the retarding layer;is the rate of change of temperature; t (T) sn Is lower layer temperature data; t (T) sn Is upper layer temperature data; h is the blocking layer thickness.
In this embodiment, a plurality of upper layer temperature data and a plurality of lower layer temperature data are adopted, and are respectively substituted into a preset first formula to determine a plurality of heat conduction rates.
Step 503, determining a temperature field distribution corresponding to the cable based on the plurality of heat conduction rates.
Further, step 503 may include the following substeps S31-S34:
s31, substituting each first heat conduction rate and each second heat conduction rate into a preset second formula respectively, and determining a first heat flux corresponding to the first end of the cable and a second heat flux sum corresponding to the second end of the cable;
s32, carrying out difference value operation on the first heat flux sum and the second heat flux sum, and determining the heat flux difference of the actual working condition;
s33, calculating the hot spot contact resistance of the actual working condition by adopting a preset experiment heat dissipation capacity ratio and the heat flux difference of the actual working condition;
s34, determining temperature field distribution corresponding to the cable based on the hot spot contact resistance under the actual working condition.
Optionally, the preset second formula is specifically:
in which Q w1 Is a first heat flux sum; q (Q) w2 Is the second heat flux sum; d is the cable diameter; l is the side length of the temperature sensor; q (Q) sn1 A first heat transfer rate for an nth temperature sensor group corresponding to the first end of the cable;S c s is the contact area of the temperature sensor and the cable c =L 2 ;Q sn2 A second heat transfer rate for an nth temperature sensor group corresponding to the second end of the cable.
In this embodiment, the temperature field distribution corresponding to the cable is determined based on the plurality of heat transfer rates.
In the embodiment of the application, the application provides a cable temperature field distribution measurement method, which comprises the steps of firstly acquiring a plurality of temperature data corresponding to a first end and a second end of a cable, wherein the temperature data comprises upper temperature data and lower temperature data, then respectively substituting each upper temperature data and corresponding lower temperature data into a preset first formula to determine a plurality of heat conduction rates, and finally determining the temperature field distribution corresponding to the cable based on the plurality of heat conduction rates; according to the scheme, the acquired upper temperature data and lower temperature data corresponding to the first end and the second end of the cable are subjected to algorithm operation, so that the temperature field distribution process corresponding to the cable is determined, and compared with the existing process of modeling and calculating the temperature field of the cable based on a finite element simulation analysis method, the process that the temperature field distribution result can be obtained only by carrying out simulation calculation on each joint can greatly reduce the calculation amount of the temperature field of the cable, and the calculation efficiency of the temperature field of the cable is improved.
In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. The cable temperature field distribution measuring device is characterized by comprising a cable, a plurality of temperature sensor groups, a retarding layer, a temperature acquisition mechanism and a calculation unit;
the blocking layer is sleeved on the cable;
each temperature sensor group is connected with the cable through embedding the blocking layer and is respectively and equidistantly arranged at the first end and the second end of the cable;
each temperature sensor group is connected with the temperature acquisition mechanism;
the temperature acquisition mechanism is in communication connection with the computing unit;
the temperature sensor group is used for acquiring temperature data corresponding to the first end of the cable and the second end of the cable and transmitting the temperature data to the temperature acquisition mechanism;
the temperature acquisition mechanism is used for receiving the temperature data transmitted by each temperature sensor group and sending the temperature data to the calculation unit;
the computing unit is used for acquiring and determining temperature field distribution corresponding to the cable based on the plurality of temperature data.
2. The cable temperature field distribution measurement device of claim 1, wherein the temperature sensor group comprises a first temperature sensor, a heat conducting layer and a second temperature sensor arranged in sequence;
the first temperature sensor and the second temperature sensor are connected with the temperature acquisition mechanism;
the first temperature sensor is used for acquiring upper temperature data corresponding to the first end of the cable and the second end of the cable and transmitting the upper temperature data to the temperature acquisition mechanism;
the second temperature sensor is used for acquiring lower-layer temperature data corresponding to the first end of the cable and the second end of the cable, and transmitting the lower-layer temperature data to the temperature acquisition mechanism.
3. The cable temperature field distribution measurement device according to claim 2, wherein the calculation unit is specifically configured to:
substituting each upper layer temperature data and corresponding lower layer temperature data into a preset first formula respectively to determine a plurality of heat conduction rates, wherein the plurality of heat conduction rates comprise a first heat conduction rate of each temperature sensor group corresponding to a first end of the cable and a second heat conduction rate of each temperature sensor group corresponding to a second end of the cable;
substituting each first heat conduction rate and each second heat conduction rate into a preset second formula respectively to determine a first heat flux corresponding to the first end of the cable and a second heat flux sum corresponding to the second end of the cable;
performing difference operation on the first heat flux sum and the second heat flux sum to determine the heat flux difference of the actual working condition;
calculating the hot spot contact resistance of the actual working condition by adopting a preset experiment heat dissipation capacity ratio and the actual working condition heat flux difference;
and determining the temperature field distribution corresponding to the cable based on the hot spot contact resistance under the actual working condition.
4. A cable temperature field distribution measuring apparatus according to claim 3, wherein the predetermined first formula is specifically:
in which Q sn A heat transfer rate for an nth temperature sensor group; k is the thermal conductivity of the heat conducting part of the retarding layer; s is the contact area between the temperature sensor and the retarding layer;is the rate of change of temperature; t (T) sn1 Is lower layer temperature data; t (T) sn2 Is upper layer temperature data; h is the thickness of the retarding layer;
the preset second formula specifically comprises the following steps:
in which Q w1 Is a first heat flux sum; q (Q) w2 Is the second heat flux sum; d is the cable diameter; l is the side length of the temperature sensor; q (Q) sn1 A first heat transfer rate for an nth temperature sensor group corresponding to the first end of the cable; s is S c S is the contact area of the temperature sensor and the cable c =L 2 ;Q sn2 A second heat transfer rate for an nth temperature sensor group corresponding to the second end of the cable.
5. The cable temperature field distribution measurement apparatus of claim 2, wherein the thermal conductivity of the thermally conductive layer is higher than the thermal conductivity of the retarding layer.
6. A method for measuring a cable temperature field distribution, comprising:
acquiring a plurality of temperature data corresponding to a cable first end and a cable second end of a cable, wherein the temperature data comprise upper-layer temperature data and lower-layer temperature data;
each upper layer temperature data and corresponding lower layer temperature data are adopted and respectively substituted into a preset first formula to determine a plurality of heat conduction rates;
and determining a temperature field distribution corresponding to the cable based on a plurality of the heat conduction rates.
7. The method of claim 6, wherein the plurality of heat transfer rates includes a first heat transfer rate for each temperature sensor group corresponding to a first end of the cable and a second heat transfer rate for each temperature sensor group corresponding to a second end of the cable; the step of determining a temperature field distribution corresponding to the cable based on a plurality of the heat conduction rates includes:
substituting each first heat conduction rate and each second heat conduction rate into a preset second formula respectively to determine a first heat flux corresponding to the first end of the cable and a second heat flux sum corresponding to the second end of the cable;
performing difference operation on the first heat flux sum and the second heat flux sum to determine the heat flux difference of the actual working condition;
calculating the hot spot contact resistance of the actual working condition by adopting a preset experiment heat dissipation capacity ratio and the actual working condition heat flux difference;
and determining the temperature field distribution corresponding to the cable based on the hot spot contact resistance under the actual working condition.
8. The method for measuring a cable temperature field distribution according to claim 6, wherein the preset first formula is specifically:
in which Q sn A heat transfer rate for an nth temperature sensor group; k is the thermal conductivity of the heat conducting part of the retarding layer; s is the contact area between the temperature sensor and the retarding layer;is the rate of change of temperature; t (T) sn Is lower layer temperature data; t (T) sn2 Is upper layer temperature data; h is the blocking layer thickness.
9. The method for measuring a cable temperature field distribution according to claim 7, wherein the preset second formula is specifically:
in which Q w1 Is a first heat flux sum; q (Q) w2 Is the second heat flux sum; d is the cable diameter; l is the side length of the temperature sensor; q (Q) sb A first heat transfer rate for an nth temperature sensor group corresponding to the first end of the cable; s is S c S is the contact area of the temperature sensor and the cable c =L 2 ;Q sn A second heat transfer rate for an nth temperature sensor group corresponding to the second end of the cable.
10. An electronic device comprising a memory and a processor, the memory having stored therein a computer program which, when executed by the processor, causes the processor to perform the steps of cable temperature field distribution measurement according to any of claims 6-9.
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