Method, system and equipment for measuring thermal resistance of ice-coated insulated wire in ice melting process and medium

Abstract

The invention relates to the technical field of ice melting, and discloses a thermal resistance measuring method, system, equipment and medium for an ice-coated insulated conductor in an ice melting process, and the method comprises the steps: arranging an insulated conductor in a temperature-controllable refrigeration house, connecting two ends of the insulated conductor with an ice melting test power supply, removing an insulating layer at two positions near one end of the conductor, and connecting a voltage measuring line; a plurality of infrared temperature measurement units are axially arranged in the middle section of the wire at intervals, are aligned with the outer surface of the wire and are positioned on the same horizontal plane; the infrared temperature measurement control module collects the surface temperature of the wire at fixed time intervals, and the voltage and current measurement system synchronously records the voltage drop of the wire and the output current of the power supply at fixed sampling frequency. After uniform ice coating is formed, constant ice melting power is applied, temperature, voltage and current data are recorded in the whole process, thermal resistance per unit length, conductor real-time temperature, dynamic internal and external temperature difference and dynamic ice melting thermal resistance are calculated hourly based on the data, and then thermal resistance, heat conductivity coefficient and natural convection heat transfer coefficient of an insulating layer are determined.

Description

Technical Field

[0001] This invention relates to the field of de-icing technology, and in particular to a method, system, equipment, and medium for measuring the thermal resistance during the de-icing process of ice-covered insulated wires. Background Technology

[0002] When ice-covered insulated conductors operate in winter, the ice buildup on the conductor surface can easily increase the line load and reduce insulation performance, necessitating de-icing to ensure power supply safety. Traditional de-icing technologies for ice-covered conductors focus primarily on de-icing power output and the final de-icing effect, lacking monitoring of the dynamic changes in thermal resistance during the de-icing process, and making it difficult to accurately obtain key parameters such as the thermal characteristics of the insulation layer and the laws governing natural convection heat transfer.

[0003] Because the de-icing process involves multiple physical processes such as conductor heat conduction, ice melting, and environmental heat exchange, the parameter coupling relationship is complex. Traditional methods cannot quantify the de-icing efficiency and heat loss distribution, making it difficult to formulate suitable de-icing schemes for different icing conditions. When the ice thickness is uneven or the ambient temperature fluctuates, improper parameter configuration may even cause problems such as conductor overheating or incomplete de-icing. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a method, system, device and medium for measuring the thermal resistance of iced insulated wires during the icing process, which can solve the problem that the existing technology is prone to overheating of the wires or incomplete icing when the icing thickness is uneven or the ambient temperature fluctuates.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for measuring the thermal resistance during the de-icing process of an ice-covered insulated conductor, comprising: Install an insulated wire inside a temperature-controlled cold storage room; Connect the de-icing test power supply to both ends of the insulated wire, remove the surface insulation layer at two locations near one end of the insulated wire, and connect the test line of the voltage measurement system. Multiple infrared temperature measuring units are arranged axially at intervals in the middle section of the insulated conductor. Each infrared temperature measuring unit is aligned with the outer surface of the ice-covered insulated conductor and is at the same horizontal plane as the center of the conductor. The infrared temperature measurement unit is configured to collect temperature data of the outer surface of the ice-covered insulated wire at fixed time intervals; A voltage and current measurement system is configured to synchronously record the voltage drop data of the insulated conductor and the current data output by the de-icing test power supply at a fixed sampling frequency.

[0007] As a preferred embodiment of the thermal resistance measurement method for the de-icing process of the iced insulated conductor described in this invention, it further includes: The cold storage temperature is adjusted to a preset low temperature, and a uniform ice layer is formed on the surface of the insulated wire in the voltage measurement section by spraying until the ice layer thickness reaches the preset thickness. Based on the conductor cross-sectional area of ​​the insulated wire, select the corresponding DC test current from the preset current parameter table as the initial de-icing current; Based on the initial de-icing current, conductor cross-sectional area, and wire length, the constant de-icing power is calculated, and the de-icing test power supply is configured to output the constant de-icing power.

[0008] As a preferred embodiment of the thermal resistance measurement method for the de-icing process of the iced insulated conductor described in this invention, it further includes: Start the ice-melting test power supply and allow it to continuously output a constant ice-melting power. The infrared temperature measurement unit collects the temperature data of the outer surface of the ice-covered insulated wire, the voltage data collected by the voltage measurement system, and the current data collected by the current measurement system. After the ice has completely melted, save the temperature, voltage, and current data throughout the entire melting process.

[0009] As a preferred embodiment of the thermal resistance measurement method for the de-icing process of the iced insulated conductor described in this invention, it further includes: At fixed time intervals, the thermal resistance value of a unit length of insulated wire is calculated based on the voltage and current data recorded at each moment. The thermal resistance value is determined by the voltage, current and wire length at that moment.

[0010] As a preferred embodiment of the thermal resistance measurement method for the de-icing process of the iced insulated conductor described in this invention, it further includes: The real-time temperature of the conductor at each moment is calculated based on the thermal resistance value per unit length, the initial resistance value of the conductor before the start of ice melting, the initial temperature of the conductor before the start of ice melting, and the temperature coefficient of resistance of the conductor material at standard temperature. The real-time temperature is determined by the initial temperature, the initial resistance value, the current thermal resistance value, and the temperature coefficient of resistance.

[0011] As a preferred embodiment of the thermal resistance measurement method for the de-icing process of the iced insulated conductor described in this invention, it further includes: The average outer surface temperature of the ice-covered insulated wire at that moment is obtained by arithmetically averaging the outer surface temperature data collected by multiple infrared temperature measurement units at the same time. The difference between the real-time temperature of the conductor at that moment and the average temperature of the outer surface is calculated as the dynamic internal and external temperature difference at that moment.

[0012] As a preferred embodiment of the thermal resistance measurement method for the de-icing process of the iced insulated conductor described in this invention, it further includes: The dynamic de-icing thermal resistance of a unit length of iced insulated wire is calculated based on the dynamic internal and external temperature difference and the heat power consumed per unit length of insulated wire. The dynamic de-icing thermal resistance is determined by the dynamic internal and external temperature difference and the heat power per unit length. Also includes: The value of the dynamic ice-melting thermal resistance at the beginning of ice melting is taken as the thermal resistance of the insulation layer; Calculate the thermal conductivity of the insulation layer based on the thermal resistance of the insulation layer, the inner diameter of the conductor, and the outer diameter of the insulation layer. The equivalent thermal resistance of natural convection heat transfer is obtained by subtracting the thermal resistance of the insulation layer from the value of the dynamic ice melting thermal resistance at the end of ice melting. The natural convection heat transfer coefficient is calculated based on the equivalent thermal resistance of natural convection heat transfer, ambient temperature, average surface temperature of the iced insulated conductor at the end of the thawing process, and outer diameter after icing.

[0013] Secondly, the present invention provides a thermal resistance measurement system for the de-icing process of ice-covered insulated wires, comprising: Temperature-controlled cold storage; Insulated wires arranged within the cold storage; An ice-melting test power supply, wherein the ice-melting test power supply is connected to both ends of the insulated wire; The voltage measurement system has a test line connected to two locations near one end of the insulated conductor where the surface insulation layer has been removed. Multiple infrared temperature measuring units are arranged axially at intervals along the middle section of the insulated wire, with each infrared temperature measuring unit aligned with the outer surface of the insulated wire and at the same horizontal plane as the center of the wire. An infrared temperature measurement and control module is connected to the plurality of infrared temperature measurement units and is configured to collect temperature data of the outer surface of the insulated wire at fixed time intervals. A voltage and current measurement system is connected to the insulated wire and the de-icing test power supply, and is configured to synchronously record the voltage drop data of the insulated wire and the current data output by the de-icing test power supply at a fixed sampling frequency.

[0014] Thirdly, the present invention provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described above.

[0015] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0016] Compared with existing technologies, the beneficial effects of this invention are that it proposes a method for measuring the thermal resistance of an ice-covered insulated conductor during the ice-melting process. An insulated conductor is arranged in a temperature-controlled cold storage room, with both ends connected to a melting test power supply. The insulation layer is removed at two points near one end of the conductor, and voltage measuring lines are connected. Multiple infrared temperature measuring units are spaced axially along the middle section of the conductor, aligned with the outer surface of the conductor and at the same horizontal plane. The surface temperature of the conductor is collected at fixed time intervals by an infrared temperature control module, while a voltage and current measurement system synchronously records the voltage drop across the conductor and the power supply output current at a fixed sampling frequency. After uniform ice formation, a constant melting power is applied, and temperature, voltage, and current data are recorded throughout the process. Based on the data, the thermal resistance per unit length, the real-time temperature of the conductor, the dynamic internal and external temperature difference, and the dynamic melting thermal resistance are calculated hourly, thereby determining the insulation layer thermal resistance, thermal conductivity, and natural convection heat transfer coefficient. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a method for measuring the resistance temperature during the de-icing process of an ice-covered insulated wire, as provided in one embodiment of the present invention.

[0019] Figure 2 This diagram illustrates an example of the layout of a thermal resistance measurement system for the melting process of an icy insulated conductor, as provided in an embodiment of the present invention.

[0020] Figure 3 An example diagram of infrared temperature measurement on the surface of an ice-covered insulated conductor is provided as part of an embodiment of the present invention for measuring the thermal resistance during the ice-melting process of an ice-covered insulated conductor.

[0021] Figure 4 This invention provides a method for measuring the thermal resistance of an icing-covered insulated wire during the melting process, which includes a conductor temperature curve and an average surface temperature curve of the icing-covered insulation.

[0022] Figure 5 A dynamic internal and external temperature difference curve (95mm) of an icing-insulated conductor is provided as part of a method for measuring the thermal resistance during the melting process of an icing-insulated conductor according to an embodiment of the present invention. 2 Insulated wire test data).

[0023] Figure 6This invention provides a method for measuring the thermal resistance per unit length (95mm) of an ice-covered insulated conductor during the ice-melting process, according to an embodiment of the present invention. 2 Insulated wire test data).

[0024] Figure 7 This is an internal structural diagram of an electronic device for measuring the thermal resistance during the de-icing process of an ice-covered insulated wire, as provided in an embodiment of the present invention. Detailed Implementation

[0025] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0026] It should be noted in advance that the system mentioned in the embodiments as the subject of real-time operation refers to any system configured with this method.

[0027] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a method for measuring the thermal resistance during the de-icing process of an ice-covered insulated wire, comprising: This invention provides a method that can effectively solve the problems mentioned above. The following will describe in detail how to implement the thermal resistance measurement method for the ice-covered insulated wire during the ice melting process using multiple embodiments. Figure 1 A flowchart illustrating a method for measuring the resistance temperature and thermal conductivity (RTD) during the de-icing process of an ice-covered insulated conductor is shown, including: S101, Install an insulated wire in a temperature-controlled cold storage room; Connect the de-icing test power supply to both ends of the insulated wire, remove the surface insulation layer at two locations near one end of the insulated wire, and connect the test line of the voltage measurement system. It should be noted that in actual operation, the current-heat effect inside the conductor of the ice-covered insulated wire will cause temperature changes during the ice melting process. The conductor resistance changes non-linearly with temperature. If the actual voltage drop across the conductor cannot be accurately obtained, the real-time thermal resistance value of the conductor during the ice melting process cannot be accurately calculated.

[0028] For example, when applying a constant de-icing power to an ice-covered insulated conductor in a cold storage environment, if the insulation layer is still retained at the voltage measurement point, the measured voltage will include interference from the interface contact resistance and surface potential of the insulation layer. This will cause the calculated conductor resistance to deviate significantly from the true value, and may even lead to a misjudgment of the conductor's temperature rise state, thereby affecting the safety and effectiveness of the de-icing strategy.

[0029] For example, if the voltage measurement point is located far from the current injection point, the voltage drop of the line itself, combined with the contact impedance, will introduce additional errors, distorting the results of the resistance temperature reading (RTD) calculation. If only the power supply output voltage is used as the conductor voltage for calculation, the voltage drop of the conductor itself and contact losses will be ignored, leading to an underestimation of the conductor temperature rise, resulting in insufficient de-icing current or failure to identify overheating risks.

[0030] Therefore, the surface insulation layer must be precisely removed at two adjacent locations near one end of the insulated wire and directly connected to the test line of the voltage measurement system to ensure that the collected voltage signal strictly corresponds to the potential difference of the conductor body, thereby providing high-precision raw data support for subsequent hourly calculation of the thermal resistance per unit length based on Ohm's law.

[0031] S102, Multiple infrared temperature measuring units are arranged at axial intervals in the middle section of the insulated conductor, and each infrared temperature measuring unit is aligned with the outer surface of the ice-covered insulated conductor and is at the same horizontal plane as the center of the conductor. It is understandable that when the ice layer thickness is unevenly distributed or there are local air gaps during the ice melting test, relying solely on the conductor resistance to invert the temperature without simultaneously obtaining the actual heat distribution on the outer surface of the conductor will lead to misjudgments of the ice melting front position and the ice melting completion status.

[0032] If a single-point contact temperature measurement method is used, it will not be able to cover the entire icing area, and the contact probe is prone to frost and failure in low temperature and high humidity environments, which will result in missing or delayed temperature data, thus affecting the real-time performance and safety of the de-icing current control.

[0033] Therefore, after detecting the start of the ice melting process, the present invention activates a non-contact multi-point synchronous infrared temperature measurement mechanism, which arranges multiple infrared temperature measurement units at equal intervals along the axial direction in the middle section of the insulated conductor to ensure that the optical axis of each infrared temperature measurement unit is vertically aligned with the outer surface of the ice-covered insulated conductor and is strictly kept at the same horizontal plane as the center of the conductor, so as to eliminate radiation temperature measurement errors caused by viewing angle deviation.

[0034] The infrared temperature measurement unit mentioned above can be understood as a key sensing component used in this invention to capture the axial temperature distribution characteristics of the outer surface of the ice-covered insulated wire in real time, verify the consistency of the conductor thermal model inversion results, and provide boundary feedback for dynamically adjusting the output of the de-icing power supply.

[0035] S103 is equipped with an infrared temperature measurement unit to collect temperature data of the outer surface of the ice-covered insulated wire at fixed time intervals. It is worth noting that when the ice layer melts unevenly or dry zones appear in some areas during the de-icing process, if temperature data is collected using non-timed or manual triggering methods, the temperature change process of the key phase change stage will be missing, making it impossible to accurately capture the critical point of ice shedding, which in turn affects the judgment of the timing of de-icing power supply regulation.

[0036] However, if continuous high-frequency sampling is relied upon without setting a unified time reference, the efficiency of subsequent thermal model fitting will decrease due to data redundancy and storage overload. At the same time, the time asynchrony between different infrared temperature measurement units will introduce axial temperature distribution artifacts, misleading the identification of the direction of the melting front.

[0037] Therefore, after activating the infrared temperature measurement unit, this invention forces all infrared temperature measurement units to synchronously collect temperature data of the outer surface of the ice-covered insulated conductor at a preset fixed time interval, ensuring that the time series has strict consistency and comparability, and providing structured input for constructing the conductor's axial dynamic temperature rise curve.

[0038] The aforementioned fixed time interval can be understood as a core timing control parameter used in this invention to ensure the time alignment of multi-point infrared temperature measurement data and to support subsequent synchronous thermal resistance inversion and icing state discrimination with the voltage measurement system.

[0039] S104, configured with a voltage and current measurement system to synchronously record voltage drop data of insulated wires and current data output by the de-icing test power supply at a fixed sampling frequency.

[0040] In some embodiments, the temperature of the cold storage is adjusted to a preset low temperature, and a uniform ice layer is formed on the surface of the insulated wire in the voltage measurement section by spraying until the thickness of the ice layer reaches the preset thickness. Based on the conductor cross-sectional area of ​​the insulated wire, select the corresponding DC test current from the preset current parameter table as the initial de-icing current; Based on the initial de-icing current, conductor cross-sectional area, and wire length, the constant de-icing power is calculated, and the de-icing test power supply is configured to output constant de-icing power.

[0041] In some embodiments, the ice-melting test power supply is activated and continuously outputs a constant ice-melting power. The infrared temperature measurement unit collects the temperature data of the outer surface of the ice-covered insulated wire, the voltage data collected by the voltage measurement system, and the current data collected by the current measurement system. After the ice has completely melted, save the temperature, voltage, and current data throughout the entire melting process.

[0042] It should be noted that in actual operation, the thermal response characteristics of the iced insulated wires in the de-icing test are highly dependent on the consistency of the initial icing state and the stability of the electrothermal input. Deviations in the initial icing thickness or fluctuations in the de-icing power will directly lead to distortion of the conductor temperature rise rate, thereby affecting the accurate identification of the de-icing critical point and the evolution law of thermal resistance.

[0043] Optionally, the above-mentioned ice-melting test procedure may include the following operations performed in sequence: First, the internal temperature of the environmental test cold storage is adjusted to -15 degrees Celsius and maintained at this temperature for at least two hours to ensure uniform thermal field in the test space. Then, the top atomizing spray device is activated to continuously spray deionized water onto the surface of the voltage measurement section of the horizontally erected insulated wire. The spray flow rate and duration are controlled to form an axially continuous cylindrical ice layer with a thickness of eight millimeters on the surface of the wire.

[0044] Furthermore, based on the cross-sectional area of ​​the aluminum core conductor of the insulated wire being tested being 180 square millimeters, the corresponding DC test current is determined to be 320 amperes by consulting the preset current parameter table, and this current value is set as the initial de-icing current.

[0045] Furthermore, based on the initial de-icing current of 320 amperes, the conductor cross-sectional area of ​​180 square millimeters, and the conductor length of the voltage measurement section of 3 meters, the constant de-icing power was calculated to be 1,920 watts by substituting the Joule heating formula, and the de-icing test power supply was configured to operate in constant power mode accordingly.

[0046] Furthermore, the de-icing test power supply is activated, continuously applying DC current to the insulated wire at a constant power of 1,920 watts. At the same time, the infrared temperature measurement unit is triggered to collect the temperature of the outer surface of the wire at a fixed time interval of 10 times per second, and the voltage and current measurement system is triggered to synchronously record the voltage drop across the wire and the power supply output current at a fixed sampling frequency of 10,000 Hz per second.

[0047] Finally, after infrared thermometry data determined that the ice layer had completely disappeared and the surface temperature of the conductor had stabilized, the power supply for the de-icing test was stopped. The temperature, voltage, and current data collected throughout the process were packaged and stored in the local test database with a unified timestamp for subsequent thermal model verification and de-icing strategy optimization.

[0048] It should be noted that the aforementioned preset current parameter table includes, but is not limited to, a mapping relationship table pre-calibrated according to the IEC 60826 standard, which combines the temperature coefficient of resistance of conductor materials with the safe current carrying capacity boundary.

[0049] It should also be noted that the voltage measurement section mentioned above can be understood in this invention as specifically referring to the physical section between two de-insulation treatment points near one end of the insulated conductor, used to accurately obtain the voltage drop of the conductor itself. Constant melting power can be understood in this invention as the core control parameter used to ensure a constant heat input rate during the melting process, thereby achieving repeatable thermal response observation. Fixed sampling frequency can be understood in this invention as a key hardware configuration indicator used to ensure time alignment of electrical parameters and support high-precision instantaneous resistance inversion.

[0050] In some embodiments, the thermal resistance value of a unit length of insulated wire is calculated at fixed time intervals based on the voltage and current data recorded at each moment. The thermal resistance value is determined by the voltage, current and wire length at that moment.

[0051] In some embodiments, the real-time temperature of the conductor at each moment is calculated based on the thermal resistance value per unit length, the initial resistance value of the conductor before the start of ice melting, the initial temperature of the conductor before the start of ice melting, and the temperature coefficient of resistance of the conductor material at a standard temperature. The real-time temperature is determined by the initial temperature, the initial resistance value, the current thermal resistance value, and the temperature coefficient of resistance.

[0052] In some embodiments, the arithmetic mean of the outer surface temperature data collected by multiple infrared temperature measurement units at the same time is used to obtain the average outer surface temperature of the ice-covered insulated wire at that time. The difference between the real-time temperature of the conductor at that moment and the average temperature of the outer surface is calculated as the dynamic internal and external temperature difference at that moment.

[0053] In some embodiments, the dynamic de-icing thermal resistance of a unit length of iced insulated wire at that moment is calculated based on the dynamic internal and external temperature difference and the heat power consumed per unit length of insulated wire. The dynamic de-icing thermal resistance is determined by the dynamic internal and external temperature difference and the heat power per unit length. It should be understood that when the heat conduction path of an ice-covered insulated conductor changes dynamically due to the phase change of the ice layer during the ice melting process, if the conductor temperature is calculated solely based on the static resistance temperature rise model, it will be impossible to reflect the real-time modulation effect of the ice layer on the conductor's heat dissipation capacity, which will lead to a delay or advance in the judgment of the completion time of ice melting.

[0054] However, if the coupling relationship between dynamic internal and external temperature difference and thermal power is ignored, and the thermal resistance of the conductor is directly equated with the overall thermal resistance of the ice covering, the two physical processes of conductor self-heating and ice covering heat transfer will be confused, resulting in a distorted assessment of the ice melting efficiency and even a misjudgment of the risk of local dry band formation.

[0055] After acquiring synchronously collected voltage, current, and infrared surface temperature data, this invention initiates a multi-physics coupling inversion mechanism. First, it calculates the thermal resistance per unit length of the conductor based on Ohm's law at each time step. Then, it inverts the real-time internal temperature of the conductor by combining the known initial resistance, initial temperature, and the temperature coefficient of resistance of the aluminum conductor. Finally, it uses the difference between the real-time temperature of the conductor and the infrared-measured outer surface temperature as the dynamic internal and external temperature difference. Combined with the Joule heat power per unit length, it solves for the dynamic melting thermal resistance that characterizes the instantaneous heat conduction properties of the ice layer.

[0056] The aforementioned dynamic melting thermal resistance can be understood as a time-varying thermal parameter used in this invention to quantify the degree to which the ice layer hinders the outward transfer of heat from the conductor during the melting process. Its value directly reflects the combined effect of ice thickness reduction and ice-water phase change on the overall thermal resistance.

[0057] In some embodiments, the value of the dynamic de-icing thermal resistance at the start of de-icing is taken as the thermal resistance of the insulation layer. Calculate the thermal conductivity of the insulation layer based on the thermal resistance of the insulation layer, the inner diameter of the conductor, and the outer diameter of the insulation layer. The equivalent thermal resistance of natural convection heat transfer is obtained by subtracting the thermal resistance of the insulation layer from the value of the dynamic ice melting thermal resistance at the end of ice melting. The natural convection heat transfer coefficient is calculated based on the equivalent thermal resistance of natural convection heat transfer, ambient temperature, average surface temperature of the iced insulated conductor at the end of the thawing process, and outer diameter after icing.

[0058] It should be noted that when evaluating the heat exchange characteristics of the iced insulated conductor after the ice has melted, directly treating the entire dynamic melting thermal resistance as a single thermal resistance without distinguishing between the inherent thermal resistance of the insulation layer and the external convective thermal resistance will lead to confusion in the identification of the thermal conductivity of the insulation material and the heat dissipation capacity of air convection, thereby affecting the accuracy of subsequent melting model parameter calibration.

[0059] If the typical thermal conductivity or convection coefficient in the standard manual is used instead of the measured value, the actual insulation material aging, the roughness of the icing surface and the airflow disturbance in the cold storage will not be taken into account, which will cause the thermal simulation results to deviate significantly from the actual physical process. In severe cases, it may misjudge the long-term operating safety of the line in the low temperature and high humidity environment.

[0060] Therefore, after obtaining the dynamic melting thermal resistance sequence of the complete melting process, the present invention initiates the thermal resistance decomposition and property inversion mechanism to extract the characteristic thermal resistance values ​​at the beginning and end of the melting process, and independently calculates the thermal conductivity and natural convection heat transfer coefficient of the insulation layer.

[0061] Optionally, the specific operations of the above-mentioned thermal resistance decomposition and property inversion may include the following steps: We can first extract the thermal resistance value corresponding to the start of the ice melting from the dynamic ice melting thermal resistance time series and define it as the thermal resistance of the insulation layer. At this moment, the ice has not yet melted and the external heat exchange is only undertaken by the insulation layer. Furthermore, based on the thermal resistance of the insulation layer, the known inner diameter of the conductor aluminum core is 15.2 mm, and the outer diameter of the insulation layer is 18.5 mm, the thermal conductivity of the insulation layer material is calculated by substituting it into the steady-state heat conduction formula of the cylindrical wall. Furthermore, after the ice has completely melted, the thermal resistance value corresponding to the end of the ice melting is extracted from the dynamic ice melting thermal resistance sequence, and the aforementioned determined insulation layer thermal resistance is subtracted. The difference obtained is the equivalent thermal resistance of natural convection heat transfer. Furthermore, by combining the equivalent thermal resistance of natural convection heat transfer, the ambient temperature of the cold storage being -10 degrees Celsius, the average temperature of the outer surface of the conductor recorded by the infrared temperature measurement unit being 4.3 degrees Celsius, and the outer diameter of the insulation layer restored after the ice melts being 18.5 millimeters, and substituting these into the thermal resistance model of natural convection heat transfer on the outer surface of the cylinder, the natural convection heat transfer coefficient can be solved.

[0062] The aforementioned thermal resistance of the insulation layer can be understood as an inherent thermal parameter used in this invention to characterize the ability of the insulation material itself to impede the outward conduction of heat from the conductor; the equivalent thermal resistance of natural convection heat transfer can be understood as a dynamic thermal resistance component used in this invention to quantify the convective heat transfer resistance between the exposed insulation surface and the surrounding cold air after the ice melt is completed; the dynamic ice melt thermal resistance can be understood as a comprehensive time-varying thermal resistance index that integrates the entire process of ice-covering phase change, insulation heat conduction, and external convection in this invention.

[0063] Example 2: Based on the above examples, a specific implementation of a method for measuring the thermal resistance during the melting process of an ice-covered insulated wire can be designed as follows: The cold storage facility is equipped with insulated wires, an infrared temperature measurement array, a voltage and current measurement system, a power supply for the ice-melting test, and related wiring. See the example below. Figure 2 .

[0064] Take an insulated wire of length L (L>10m); connect the two ends of the insulated wire to the de-icing test power supply; break the surface insulation layer at both ends of the insulated wire at a distance of 10m and connect it to the measuring line of the voltage measurement system; arrange a set of infrared temperature measuring units every 1m within a 9m length range in the middle of the insulated wire.

[0065] Furthermore, an infrared temperature measurement array was constructed to measure the surface temperature of the iced insulated conductor. This array consists of ten 1m-spaced infrared temperature measurement units. Each unit is located on the same horizontal plane as the center of the iced conductor, and the infrared measurement point is located on the surface of the iced insulated conductor. Figure 3Example diagrams are provided. Each infrared temperature measurement unit records the temperature change on the surface of the ice-covered line conductor during the de-icing process, with a set of data per second, and saves the data to the computer.

[0066] Furthermore, a voltage and current measurement system is set up to record the voltage drop of the insulated wires and the de-icing current data output by the de-icing test power supply during the de-icing process at a sampling rate of not less than 1.2 kHz.

[0067] Furthermore, the surface of the insulated conductors in the voltage measurement section is iced, and the initial de-icing current and de-icing power output of the de-icing test power supply are configured.

[0068] Furthermore, the temperature of the cold storage was lowered to -15°C, and ice was uniformly applied to the surface of the insulated wires in the voltage measurement section by spraying until the ice thickness reached 10mm.

[0069] Furthermore, configure the initial de-icing current output of the de-icing test power supply. Depending on the different conductor types and cross-sectional areas, the initial de-icing current configured for the de-icing test power supply should be selected according to the de-icing current parameters shown in Table 1.

[0070] Table 1. Current selection parameters for cold storage de-icing tests of different types of insulated wires.

[0071] Furthermore, configure the ice-melting power output of the ice-melting test power supply. Configure the constant ice-melting power output of the ice-melting test power supply as follows: (1) Where P is the de-icing power output of the de-icing test power supply (W), I is the initial de-icing current output of the de-icing test power supply (A), and S is the cross-sectional area of ​​the conductor (mm²). 2 L is the length (m) of the insulated wire.

[0072] Furthermore, the de-icing test power supply was used to perform de-icing at a constant power P, while simultaneously recording temperature rise and voltage and current data.

[0073] Furthermore, the ice melting process begins, with the ice melting test power supply continuously outputting constant power P.

[0074] Furthermore, according to Figure 2 The wiring diagram is shown, and the temperature measurement data of the infrared temperature measurement array and the measurement data of the voltage-current measurement system are recorded simultaneously.

[0075] Furthermore, we will wait for the ice to melt completely and then save the data from the entire experiment.

[0076] Furthermore, the change in conductor resistance during the entire ice-melting process of a unit length of insulated wire was deduced from voltage-current measurement data.

[0077] The formula for calculating the conductor resistance of a unit length of insulated wire during the entire ice-melting process, with a time interval of seconds, is as follows: (2) In the formula, R(n) is the change in thermal resistance per unit length of the insulated wire during the entire ice melting process (°C‧m / W), and V(t) and I(t) are the voltage drop (V) and ice melting current (A) of the insulated wire at time t, respectively. F represents nFS+k time points. S Here, n is the sampling frequency (Hz), n is the integer time coordinate number, and k is the intermediate variable for iterative calculation.

[0078] Furthermore, by extrapolating the conductor temperature change of the insulated wire throughout the entire ice-melting process, and based on the conductor resistance temperature coefficient characteristics per unit length of insulated wire during the entire ice-melting process, the conductor temperature change law of the insulated wire during the entire ice-melting process is as follows: (3) In the formula, R(0) is the initial resistance (°C‧m / W) of the insulated conductor, and α 293 T1(0) is the temperature coefficient of the resistivity of the insulated conductor at 20℃ (1 / ℃), T1(n) is the initial temperature of the insulated conductor (℃), and T1(n) is the real-time temperature of the insulated conductor (℃).

[0079] Furthermore, the average temperature change on the surface of the icy insulated conductor is calculated from the infrared temperature measurement array data. The average temperature change on the surface of the icy insulated conductor is taken as the average value of the measurement data from the infrared temperature measurement array: (4) In the formula, T 2-k This is the data (°C) for the infrared temperature measurement sensor numbered k.

[0080] Furthermore, the temperature difference between the inside and outside of the ice-covered insulated conductor is calculated, and the variation law of the temperature difference between the inside and outside of the ice-covered insulated conductor is as follows: (5) In the formula, ΔT(n) is the dynamic internal and external temperature difference (°C) of the ice-covered insulated conductor.

[0081] Furthermore, the dynamic de-icing thermal resistance per unit length of the icing-covered conductor is calculated. The formula for calculating the dynamic de-icing thermal resistance per unit length of the icing-covered conductor throughout the entire de-icing process is as follows: (6) In the formula, RT(n) is the dynamic de-icing thermal resistance per unit length of ice-covered insulated wire (°C‧m / W).

[0082] Furthermore, the dynamic melting resistance data of the ice-covered insulated conductor per unit length were analyzed to obtain the thermal resistance and thermal conductivity of the insulation layer, as well as the equivalent thermal resistance and natural convection heat transfer coefficient.

[0083] Furthermore, the thermal resistance and thermal conductivity of the insulation layer are calculated. The initial melting resistance is equal to the thermal resistance of the insulation layer: (7) In the formula, R ins Thermal resistance of insulation layer per unit insulated conductor (°C‧m / W).

[0084] The formula for calculating the thermal conductivity of the insulation layer is: (8) In the formula, λ ins D1 is the thermal conductivity of the insulation layer (W / (℃‧m)), and D2 is the inner conductor diameter and outer insulation diameter (mm) of the insulated wire, respectively.

[0085] Furthermore, the equivalent thermal resistance and natural convection heat transfer coefficient of the insulated circuit are calculated.

[0086] The equivalent thermal resistance of natural convection heat transfer in insulated circuits: (9) In the formula, R nh The equivalent thermal resistance (°C‧m / W) of natural convection heat transfer per unit insulated conductor, n max T3 is the time number of the termination time, and T3 is the ambient temperature (°C).

[0087] Furthermore, the formula for calculating the natural convection heat transfer coefficient of an insulated circuit is: (10) In the formula, h n The natural convection heat transfer coefficient of the insulated circuit (W / m) 2 ).

[0088] Furthermore, to estimate the equivalent natural convection heat transfer coefficient during the ice-melting process, considering the entire ice-melting process, the equivalent natural convection heat transfer coefficient is: (11) In the formula, h eq The equivalent natural convection heat transfer coefficient (W / m²) of the insulated line during the entire de-icing process. 2 D3 represents the icing thickness (mm) of the insulated circuit.

[0089] Furthermore, the heat loss due to natural convection during the ice melting process is estimated. The formula for calculating the heat loss due to natural convection heat transfer is as follows: (12) In the formula, Q h The heat loss (J) is due to natural convection heat transfer during the ice melting process.

[0090] Furthermore, the energy consumed in melting the ice is calculated. The formula for calculating the energy consumed in melting the ice is: (13) (14) (15) In the formula, W represents the consumption (J), and Q... core and Q ins The heat absorption of the conductor and the heat absorption of the insulating layer are respectively (J), γ core and γ ins These are the specific heat capacities of the conductor and the insulation layer, respectively (J / kg), M core and M ins These represent the heat absorption of the conductor and the mass (kg) of the insulation layer, respectively.

[0091] Furthermore, the energy consumed in melting insulated conductors under different ice thicknesses is calculated. The formula for calculating the energy consumed in melting insulated conductors under different ice thicknesses is as follows: (16) In the formula, D4 is the ice thickness (mm) of the insulated wire.

[0092] Furthermore, the formula for calculating the minimum melting power under the condition of icing thickness D4 is as follows: (17) In the formula, P D4 The minimum melting power (W) and T are respectively for ice thickness D4. D4 These represent the duration (s) for an icing thickness D4, typically taken as 3600, Q´ h The heat loss (J) during the melting process due to natural convection heat transfer under an ice thickness of D4. h The calculation formula is (18) Compared to traditional methods that only focus on the melting results and lack monitoring of process thermal parameters, this technology clearly presents the correlation changes of conductor temperature, surface temperature, and internal and external temperature differences from the perspective of the heat exchange mechanism throughout the melting cycle, making up for the limitations of existing methods in analyzing the thermal resistance of ice-covered insulated wires during the melting process.

[0093] Example 3, referring to Figure 7 This embodiment also provides a thermal resistance measurement system for the de-icing process of iced insulated wires, including: Temperature-controlled cold storage; Insulated wires installed inside the cold storage; The de-icing test power supply is connected to both ends of the insulated wire; The voltage measurement system's test leads are connected to two locations near one end of an insulated conductor where the surface insulation layer has been removed. Multiple infrared temperature measuring units are arranged axially at intervals along the middle section of the insulated conductor. Each infrared temperature measuring unit is aligned with the outer surface of the insulated conductor and is at the same horizontal plane as the center of the conductor. An infrared temperature measurement and control module is connected to multiple infrared temperature measurement units and is configured to collect temperature data of the outer surface of the insulated wire at fixed time intervals. The voltage and current measurement system is connected to the insulated wire and the de-icing test power supply, and is configured to synchronously record the voltage drop data of the insulated wire and the current data output by the de-icing test power supply at a fixed sampling frequency.

[0094] The above-mentioned unit modules can be embedded in the processor of the electronic device in hardware form or independent of it, or they can be stored in the memory of the electronic device in software form, so that the processor can call and execute the corresponding operations of the above modules.

[0095] This embodiment also provides an electronic device, which can be a terminal, and its internal structure diagram can be as follows: Figure 7 As shown, the electronic device includes a processor, memory, communication interface, display screen, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a method for measuring the thermal resistance during the melting process of iced insulated wires. The display screen can be an LCD screen or an e-ink screen. The input device can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the device's casing, or an external keyboard, touchpad, or mouse.

[0096] This embodiment also provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, it performs the following steps: Install an insulated wire inside a temperature-controlled cold storage room; Connect the de-icing test power supply to both ends of the insulated wire, remove the surface insulation layer at two locations near one end of the insulated wire, and connect the test line of the voltage measurement system. Multiple infrared temperature measuring units are arranged axially at intervals in the middle section of the insulated conductor. Each infrared temperature measuring unit is aligned with the outer surface of the ice-covered insulated conductor and is at the same horizontal plane as the center of the conductor. Configure an infrared temperature measurement unit to collect temperature data of the outer surface of the ice-covered insulated wire at fixed time intervals; Configure a voltage and current measurement system to synchronously record the voltage drop data of the insulated wire and the current data output by the power supply for the de-icing test at a fixed sampling frequency.

[0097] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

[0098] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0099] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for measuring the thermal resistance of an ice-covered insulated conductor during the ice-melting process, characterized in that, include: Install an insulated wire inside a temperature-controlled cold storage room; Connect the de-icing test power supply to both ends of the insulated wire, remove the surface insulation layer at two locations near one end of the insulated wire, and connect the test line of the voltage measurement system. Multiple infrared temperature measuring units are arranged axially at intervals in the middle section of the insulated conductor. Each infrared temperature measuring unit is aligned with the outer surface of the ice-covered insulated conductor and is at the same horizontal plane as the center of the conductor. The infrared temperature measurement unit is configured to collect temperature data of the outer surface of the ice-covered insulated wire at fixed time intervals; A voltage and current measurement system is configured to synchronously record the voltage drop data of the insulated conductor and the current data output by the de-icing test power supply at a fixed sampling frequency.

2. The method for measuring the thermal resistance during the de-icing process of an ice-covered insulated conductor as described in claim 1, characterized in that, Also includes: The cold storage temperature is adjusted to a preset low temperature, and a uniform ice layer is formed on the surface of the insulated wire in the voltage measurement section by spraying until the ice layer thickness reaches the preset thickness. Based on the conductor cross-sectional area of ​​the insulated wire, select the corresponding DC test current from the preset current parameter table as the initial de-icing current; Based on the initial de-icing current, conductor cross-sectional area, and wire length, the constant de-icing power is calculated, and the de-icing test power supply is configured to output the constant de-icing power.

3. The method for measuring the thermal resistance of an ice-covered insulated conductor during the de-icing process as described in claim 2, characterized in that, Also includes: Start the ice-melting test power supply and allow it to continuously output a constant ice-melting power. The infrared temperature measurement unit collects the temperature data of the outer surface of the ice-covered insulated wire, the voltage data collected by the voltage measurement system, and the current data collected by the current measurement system. After the ice has completely melted, save the temperature, voltage, and current data throughout the entire melting process.

4. The method for measuring the thermal resistance during the de-icing process of an ice-covered insulated conductor as described in claim 3, characterized in that, Also includes: At fixed time intervals, the thermal resistance value of a unit length of insulated wire is calculated based on the voltage and current data recorded at each moment. The thermal resistance value is determined by the voltage, current and wire length at that moment.

5. A method for measuring the thermal resistance of an ice-covered insulated conductor during the de-icing process as described in claim 4, characterized in that, Also includes: The real-time temperature of the conductor at each moment is calculated based on the thermal resistance value per unit length, the initial resistance value of the conductor before the start of ice melting, the initial temperature of the conductor before the start of ice melting, and the temperature coefficient of resistance of the conductor material at standard temperature. The real-time temperature is determined by the initial temperature, the initial resistance value, the current thermal resistance value, and the temperature coefficient of resistance.

6. The method for measuring the thermal resistance during the de-icing process of an ice-covered insulated conductor as described in claim 5, characterized in that, Also includes: The average outer surface temperature of the ice-covered insulated wire at that moment is obtained by arithmetically averaging the outer surface temperature data collected by multiple infrared temperature measurement units at the same time. The difference between the real-time temperature of the conductor at that moment and the average temperature of the outer surface is calculated as the dynamic internal and external temperature difference at that moment.

7. A method for measuring the thermal resistance of an ice-covered insulated conductor during the de-icing process as described in claim 6, characterized in that, Also includes: The dynamic de-icing thermal resistance of a unit length of iced insulated wire is calculated based on the dynamic internal and external temperature difference and the heat power consumed per unit length of insulated wire. The dynamic de-icing thermal resistance is determined by the dynamic internal and external temperature difference and the heat power per unit length. Also includes: The value of the dynamic ice-melting thermal resistance at the beginning of ice melting is taken as the thermal resistance of the insulation layer; Calculate the thermal conductivity of the insulation layer based on the thermal resistance of the insulation layer, the inner diameter of the conductor, and the outer diameter of the insulation layer. The equivalent thermal resistance of natural convection heat transfer is obtained by subtracting the thermal resistance of the insulation layer from the value of the dynamic ice melting thermal resistance at the end of ice melting. The natural convection heat transfer coefficient is calculated based on the equivalent thermal resistance of natural convection heat transfer, ambient temperature, average surface temperature of the iced insulated conductor at the end of the thawing process, and outer diameter after icing.

8. A thermal resistance measurement system for the de-icing process of an ice-covered insulated conductor, using the method described in any one of claims 1 to 7, characterized in that, include: Temperature-controlled cold storage; Insulated wires arranged within the cold storage; An ice-melting test power supply, wherein the ice-melting test power supply is connected to both ends of the insulated wire; The voltage measurement system has a test line connected to two locations near one end of the insulated conductor where the surface insulation layer has been removed. Multiple infrared temperature measuring units are arranged axially at intervals along the middle section of the insulated wire, with each infrared temperature measuring unit aligned with the outer surface of the insulated wire and at the same horizontal plane as the center of the wire. An infrared temperature measurement and control module is connected to the plurality of infrared temperature measurement units and is configured to collect temperature data of the outer surface of the insulated wire at fixed time intervals. A voltage and current measurement system is connected to the insulated wire and the de-icing test power supply, and is configured to synchronously record the voltage drop data of the insulated wire and the current data output by the de-icing test power supply at a fixed sampling frequency.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method for measuring the thermal resistance during the de-icing process of an ice-covered insulated wire as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the thermal resistance measurement method for the ice melting process of an ice-covered insulated wire as described in any one of claims 1 to 7.

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