Method for collecting and analyzing crosslinking by-products in degassing process of XLPE cable production

Abstract

The invention discloses a method, a system and equipment for collecting and analyzing crosslinking byproducts in a degassing process of XLPE cable production, and a storage medium. The method comprises the following steps: acquiring a cable to be measured and setting a plurality of temperature measuring points; a hollow aluminum pipe is adopted to seal the cable; the method comprises the following steps: putting a to-be-detected cable into a degassing chamber, carrying out primary gas extraction, degassing, regularly carrying out gas extraction operation on the cable in a degassing process, and collecting temperature data of each inner layer of the cable in a degassing period; the method comprises the following steps: performing pressure relief on a to-be-tested cable, sampling, performing nitrogen charging, and performing regular gas taking operation on the to-be-tested cable after nitrogen charging and the to-be-tested cable which is not processed; and carrying out gas chromatographic analysis on the gas sample, and calculating the concentration of by-product gas components in the gas sample by adopting a normalization method to obtain a cross-linked by-product time sequence data diagram of the cable to be detected in the production and gas removal process. According to the invention, the overflow of byproducts in the cable gas taking operation process is reduced, so that the error of the final analysis result of the cable is reduced.

Description

Technical Field

[0001] This invention belongs to the field of cable production quality assessment technology, specifically relating to a method, system, equipment, and storage medium for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production. Background Technology

[0002] High-voltage XLPE cables (cross-linked polyethylene insulated power cables) are widely used in modern power transmission due to their excellent electrical performance, mechanical strength, and environmental protection characteristics.

[0003] For high-voltage XLPE cables, the production process requires cross-linking with peroxides to obtain cross-linked polyethylene. Currently, the most commonly used cross-linking agent is dicumyl peroxide (DCP). However, DCP generates various cross-linking byproducts during the cross-linking process, such as cumyl alcohol, acetophenone, α-methylstyrene, and methane. These byproducts are volatile substances that can severely affect the insulation quality of the cable. Therefore, to ensure the insulation quality of the cable meets standards, a degassing process is necessary after the high-voltage XLPE cable production is completed, and the cable's production quality performance is evaluated based on the degassing effect.

[0004] In existing technologies, the degassing effect of cables is usually analyzed by detecting the residual by-product content of degassed cable samples. However, this method is greatly affected by the sampling location, and samples taken from the end position usually cannot represent the state of the entire cable reel. Moreover, by-products are easily spilled during the sampling process, resulting in a large discrepancy between the collected crosslinking by-product content and the actual content, thus increasing the error of the analysis results. In addition, this method lacks monitoring of the by-product content during the cable degassing process. All these factors contribute to the incomplete and inaccurate evaluation results of the cable degassing effect. Summary of the Invention

[0005] The first objective of this invention is to overcome the shortcomings of the prior art and provide a method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production. This method strengthens the monitoring of byproduct content during the degassing process of cable production and reduces the overflow of byproducts during the cable gas sampling operation, so that the collected crosslinking byproduct content is consistent with the actual content, thereby reducing the error of the final cable analysis results and enhancing the accuracy and comprehensiveness of the cable analysis results.

[0006] The second objective of this invention is to provide a system for collecting and analyzing crosslinking byproducts during the degassing process in the production of XLPE cables.

[0007] A third objective of this invention is to provide a computer device.

[0008] A fourth objective of this invention is to provide a storage medium.

[0009] The first objective of this invention can be achieved by adopting the following technical solution:

[0010] A method for collecting and analyzing crosslinking byproducts during the degassing process in XLPE cable production, comprising the following steps:

[0011] S1. Before the cable leaves the factory, obtain at least two cables to be tested that have not undergone degassing; the cables to be tested are XLPE cables with insulated cores, inner shielding layer, main insulation layer and outer shielding layer;

[0012] S2. Set multiple temperature measuring points in the main insulation layer of the undegassed cable under test; use a hollow aluminum tube to fit onto the cable under test after setting the temperature measuring points, seal both ends of the hollow aluminum tube by argon arc welding, and set a gas sampling nozzle on the hollow aluminum tube to obtain a sealed cable under test.

[0013] S3. Place the sealed cable to be tested obtained in step S2 into the degassing chamber for the first gas extraction operation. After the first gas extraction operation is completed, perform the degassing operation on the cable to be tested after the first gas extraction. During the degassing process of the cable to be tested, perform gas extraction operation on it periodically. After the degassing of the cable to be tested is completed, collect the temperature change data of the main insulation layer of the cable to be tested throughout the entire degassing cycle through the temperature measuring point.

[0014] S4. Depressurize the degassed test cable obtained in step S3 and divide it into two parts. One part of the test cable is nitrogen-filled, while the other part is left untreated. After periodically sampling the nitrogen-filled test cable and the untreated test cable, the crosslinking byproducts of the degassing process of the test cable production are collected.

[0015] S5. Perform gas chromatography analysis on the crosslinking byproduct gas samples collected in all gas sampling operations in steps S3 and S4, and calculate the concentration of byproduct gas components in the gas samples using the normalization method to obtain a time series data diagram of crosslinking byproducts in the degassing process of the cable under test, and analyze the degree of degassing of the cable under test based on the time series data diagram of crosslinking byproducts.

[0016] Preferably, the specific process of step S2 is as follows:

[0017] First, equally spaced holes are drilled on the surface of the undegassed cable under test. The measuring end of the thermocouple is installed into the main insulation layer along the drilled holes. Holes are also drilled at corresponding positions on the hollow aluminum tube. The drilled hollow aluminum tube is then fitted onto the surface of the cable under test. The compensating end of the thermocouple is then connected to the paperless recorder along the corresponding drilled holes in the hollow aluminum tube. The paperless recorder is placed outside the hollow aluminum tube. Finally, both ends of the hollow aluminum tube are sealed using argon arc welding, and a gas sampling nozzle is installed on the hollow aluminum tube to obtain a sealed cable under test.

[0018] Preferably, the calculation of the gas sampling cycle for periodically sampling the cable under test during the degassing process in step S3 is expressed as follows:

[0019] Δt=(L2 / (π 2 D))×ln(1 / (1-r))

[0020] Where Δt is the gas extraction cycle, L is the insulation layer thickness in mm, D is the byproduct diffusion coefficient in mm / h, and r is the expected byproduct reduction rate within one gas extraction cycle, 0 < r < 1.

[0021] Preferably, before all gas sampling operations in steps S3 and S4, the gas pressure must be measured with a barometer, and then a fixed amount of gas is extracted each time using an air pump. The extracted gas is collected as a gas sample in a gas collection bag for labeling and preservation.

[0022] Preferably, the concentration of the byproduct gas components in step S5 is specifically expressed as follows:

[0023]

[0024] Where, n ik % represents the actual concentration of byproduct gaseous component i, h represents the total number of gas types, and n ik The total amount of substance of the actual gaseous component i of the byproducts.

[0025] Preferably, the length of the undegassed test cable in step S1 is at least 3 meters.

[0026] Preferably, the criteria for judging the degree of degassing of the cable under test in step S5 are as follows:

[0027] According to the data in the time series data diagram of the cross-linking byproducts corresponding to the cable under test, if the content of each cross-linking byproduct is stable in the three gas sampling tests before the end of degassing, and the fluctuation range of the cross-linking byproduct content is less than 10% of the average value of the three gas sampling tests, and the measured cross-linking byproduct gas concentration is less than 2% during the nitrogen filling stage of the cable under test, then the degassing is considered sufficient; otherwise, the degassing is insufficient.

[0028] A system for collecting and analyzing crosslinking byproducts during the degassing process in XLPE cable production, used to implement the method for collecting and analyzing crosslinking byproducts during the degassing process in XLPE cable production, the system comprising:

[0029] The test cable acquisition module is used to acquire at least two undegassed test cables before the cables leave the factory; the test cables are XLPE cables with insulated cores, inner shielding layers, main insulation layers and outer shielding layers;

[0030] The cable temperature measurement module is used to set multiple temperature measurement points in the main insulation layer of the cable under test that has not undergone degassing, and to collect temperature change data of the main insulation layer of the cable under test throughout the entire degassing cycle.

[0031] The cable sealing module is used to attach a hollow aluminum tube to the cable under test after the temperature measuring point is set, and to seal both ends of the hollow aluminum tube by argon arc welding. Finally, an air sampling nozzle is set on the hollow aluminum tube to obtain the sealed cable under test.

[0032] A sealing inspection module is used to test the sealing performance of the sealed cable under test.

[0033] The cable air sampling operation module is used to perform air sampling operations at various stages of the cable under test.

[0034] The cable degassing module is used to degas the sealed cable under test to obtain a degassed cable under test.

[0035] The cable pressure relief module is used to relieve pressure on the degassed cable under test.

[0036] A nitrogen-filled cable module is used to perform nitrogen-filled treatment on a portion of the cable under test obtained from the cable depressurization module, resulting in a nitrogen-filled cable under test.

[0037] The crosslinking byproduct time series data acquisition module is used to perform gas chromatography analysis on the gas sample obtained by the cable gas sampling operation module, and to calculate the concentration of byproduct gas components in the gas sample using the normalization method, so as to obtain the crosslinking byproduct time series data of the cable under test during the degassing process.

[0038] The cable degassing analysis module is used to analyze the degassing degree of the cable under test based on the crosslinking byproduct time series data diagram.

[0039] A computer device includes a processor and a memory for storing a processor-executable program, wherein when the processor executes the program stored in the memory, it implements the method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production.

[0040] A storage medium storing a program, which, when executed by a processor, implements a method for collecting and analyzing crosslinking byproducts during the degassing process in the production of XLPE cables.

[0041] The present invention has the following advantages over the prior art:

[0042] This invention discloses a method for collecting and analyzing crosslinking byproducts during the degassing process in XLPE cable production. The method involves sealing the cable under test with a hollow aluminum tube, then placing the cable in a degassing chamber for degassing. This effectively prevents the diffusion of byproducts during the collection and detection of byproduct concentration, thus improving upon existing methods which suffer from low sensitivity and large errors. Furthermore, this method studies the dynamic process, enhancing the monitoring of byproduct content during the degassing process in cable production. This provides more comprehensive data for subsequent cable analysis, improving the accuracy and comprehensiveness of the analysis results and laying a solid foundation for subsequent cable assembly. Attached Figure Description

[0043] Figure 1 This is a flowchart of a method for collecting and analyzing crosslinking byproducts during the degassing process in the production of XLPE cables, provided in Embodiment 1 of the present invention.

[0044] Figure 2 This is a schematic diagram showing the location of the temperature measuring point on the cable under test provided in Embodiment 1 of the present invention;

[0045] Figure 3 This is a schematic diagram of the air intake nozzle provided in Embodiment 1 of the present invention;

[0046] Figure 4 This is a reference example diagram of the time-series data of crosslinking byproducts provided in Embodiment 1 of the present invention;

[0047] Figure 5 This is a schematic diagram of the crosslinking byproduct collection and analysis system for the degassing process in the production of XLPE cables provided in Embodiment 2 of the present invention;

[0048] Figure 6 This is a schematic diagram of the structure of a computer device provided in Embodiment 3 of the present invention.

[0049] Figure 7 This is a schematic diagram of the structure of a storage medium provided in Embodiment 4 of the present invention.

[0050] In the diagram, 1 is a hollow aluminum tube; 2 is a thermocouple; 3 is an insulated wire core; 4 is an inner shielding layer; 5 is the main insulation layer; and 6 is the outer shielding layer. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0053] In the description of this invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] In the description of this invention, it should be noted that, unless otherwise explicitly specified and agreed, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] Example 1

[0056] like Figures 1-4 As shown, a method for collecting and analyzing crosslinking byproducts during the degassing process in XLPE cable production includes the following steps:

[0057] S1. Before the cable leaves the factory, two undegassed cables are obtained for testing; the cables to be tested are XLPE cables with insulated cores, inner shielding layer, main insulation layer and outer shielding layer.

[0058] Specifically, the length of the test cable that has not undergone degassing in step S1 is at least 3 meters.

[0059] S2. Set multiple temperature measuring points in the main insulation layer of the two undegassed cables under test; use a hollow aluminum tube to fit onto the cable under test after setting the temperature measuring points, seal both ends of the hollow aluminum tube by argon arc welding, and set a gas sampling nozzle on the hollow aluminum tube to obtain a sealed cable under test.

[0060] Specifically, the process of step S2 is as follows:

[0061] First, equally spaced holes are drilled on the surface of the undegassed cable under test. The measuring end of the thermocouple is installed into the main insulation layer of the cable along the drilled holes. Holes are also drilled at corresponding positions on the hollow aluminum tube. The drilled hollow aluminum tube is then fitted onto the surface of the cable under test. The compensating end of the thermocouple is then connected to the paperless recorder along the corresponding drilled holes in the hollow aluminum tube. The paperless recorder is placed outside the hollow aluminum tube. Finally, both ends of the hollow aluminum tube are sealed using argon arc welding, and a gas sampling nozzle is installed on the hollow aluminum tube to obtain a sealed cable under test.

[0062] Specifically, the length of the thermocouple needs to match the size of the degassing chamber, and the length of the thermocouple should be less than ten meters.

[0063] In this embodiment, after the cable under test is sealed, nitrogen gas needs to be injected into the gas sampling port of the cable under test, and soapy water is applied to the sealed area to test the sealing performance. If no bubbles emerge from the sealed area, it means that the sealing performance is good, and the next step can be continued. If bubbles emerge, it means that the sealing performance is insufficient, and the cable under test needs to be resealed.

[0064] S3. Place the sealed cable to be tested obtained in step S2 into the degassing chamber for the first gas extraction operation. After the first gas extraction operation is completed, perform the degassing operation on the cable to be tested after the first gas extraction. During the degassing process of the cable to be tested, perform gas extraction operation on it periodically. After the degassing of the cable to be tested is completed, collect the temperature change data of the main insulation layer of the cable to be tested throughout the entire degassing cycle through the temperature measuring point.

[0065] Specifically, in this embodiment, the two sealed test cables obtained in step S2 are placed at the air outlet and the back air outlet of the degassing chamber, respectively. Then, the two sealed test cables are connected to the air pump and the air collection bag, respectively, and an interference fit is achieved. During the air intake process of the test cables, close attention is paid to whether each connection of the air intake pipeline is kept sealed.

[0066] Specifically, the calculation of the gas sampling cycle for periodically sampling the cable under test during the degassing process described in step S3 is expressed as follows:

[0067] Δt=(L 2 / (π 2 D))×ln(1 / (1-r))

[0068] Where Δt is the gas extraction cycle, L is the insulation layer thickness in mm, D is the byproduct diffusion coefficient in mm / h, and r is the expected byproduct reduction rate within one gas extraction cycle, 0 < r < 1.

[0069] S4. Depressurize the degassed test cable obtained in step S3 and divide it into two parts. One part of the test cable is nitrogen-filled, while the other part is left untreated. After periodically sampling the nitrogen-filled test cable and the untreated test cable, the crosslinking byproducts of the degassing process of the test cable production are collected.

[0070] Specifically, before all gas sampling operations in steps S3 and S4, the gas pressure must be measured with a barometer, and then a fixed amount of gas must be extracted each time using an air pump. The extracted gas is then collected as a gas sample into a gas collection bag for labeling and preservation.

[0071] Specifically, the calculation formula for the periodic gas sampling cycle in step S4 is generally the same as that in step S3, but the diffusion coefficient of the byproduct used is different from that in step S3. The specific calculation of the gas sampling cycle in step S4 is as follows:

[0072] Δt=(L 2 / (π 2 D))×ln(1 / (1-r))

[0073] D = D0·e (-E / KT)

[0074] Where D0 is the diffusion factor in mm / h; E is the activation energy in J / mol; K is the Boltzmann constant in J / K; and T is the temperature in K (S3 is the degassing temperature, and S4 is room temperature).

[0075] S5. Perform gas chromatography analysis on the crosslinking byproduct gas samples collected in all gas sampling operations in steps S3 and S4, and calculate the concentration of byproduct gas components in the gas samples using the normalization method to obtain a time series data diagram of crosslinking byproducts in the degassing process of the cable under test, and analyze the degree of degassing of the cable under test based on the time series data diagram of crosslinking byproducts.

[0076] Specifically, the concentrations of the byproduct gas components are expressed as follows:

[0077]

[0078] Where, n ik % represents the actual concentration of byproduct gaseous component i, h represents the total number of gas types, and n ik The total amount of substance of the actual gaseous component i of the byproducts.

[0079] n ik The specific representation is as follows:

[0080]

[0081] Where, nik ′ represents the total amount of substance of gas component i extracted;

[0082] Specifically, n ik The specific representation of ′ is as follows:

[0083]

[0084] Among them, V 总 where c is the cavity volume, p is the pressure, and c is the pressure. ik Let be the relative concentration of gas component i in the k-th sampling;

[0085] Specifically, V 总 The specific representation is as follows:

[0086]

[0087] Among them, V 总 r1 is the volume of the cavity; r2 is the radius of the hollow aluminum tube; r2 is the radius of the insulated wire core; h1 is the length of the hollow aluminum tube; h2 is the length of the insulated wire core.

[0088] n im0 The specific representation is as follows:

[0089]

[0090] Where, n ik0 Vi is the amount of gas component i extracted in the k-th extraction; V0 is the volume of gas extracted in each extraction; R is the gas constant; T k The temperature of the k-th gas extraction is denoted as p; the pressure is p; and the temperature of the k-th gas extraction is c. ik Let be the relative concentration of gas component i in the k-th sampling;

[0091] Specifically, the gases detected include 12 gases such as methane, ethane, ethylene, acetylene, propane, propylene, propyne, hydrogen, oxygen, nitrogen, carbon monoxide, and carbon dioxide.

[0092] Specifically, the criteria for evaluating the degree of degassing of the cable under test in step S5 are as follows:

[0093] like Figure 4 As shown, according to the data in the time series data diagram of the cross-linking byproducts corresponding to the cable under test, if the cable under test satisfies the following conditions: the content of each cross-linking byproduct is stable in the three gas sampling tests before the end of degassing, and the fluctuation range of the cross-linking byproduct content is less than 10% of the average value of the three gas sampling tests, and the measured cross-linking byproduct gas concentration is less than 2% during the nitrogen filling stage of the cable under test, then it is considered to have sufficient degassing; otherwise, it is considered to have insufficient degassing.

[0094] Specifically, in practical applications, this method can also be used to analyze the insulation performance, dielectric performance, tensile performance, and other indicators of cables based on the time series data of the cross-linking by-products. In this embodiment, the degree of degassing of the cable is used as the analysis indicator.

[0095] Example 2

[0096] like Figure 5 As shown, a crosslinking byproduct collection and analysis system for the degassing process in XLPE cable production is provided to implement the crosslinking byproduct collection and analysis method for the degassing process in XLPE cable production as described in Example 1. The system includes:

[0097] The test cable acquisition module is used to acquire at least two undegassed test cables before the cables leave the factory; the test cables are XLPE cables with insulated cores, inner shielding layers, main insulation layers and outer shielding layers;

[0098] The cable temperature measurement module is used to set multiple temperature measurement points in the main insulation layer of the cable under test that has not undergone degassing, and to collect temperature change data of the main insulation layer of the cable under test throughout the entire degassing cycle.

[0099] The cable sealing module is used to attach a hollow aluminum tube to the cable under test after the temperature measuring point is set, and to seal both ends of the hollow aluminum tube by argon arc welding. Finally, an air sampling nozzle is set on the hollow aluminum tube to obtain the sealed cable under test.

[0100] A sealing inspection module is used to test the sealing performance of the sealed cable under test.

[0101] The cable air sampling operation module is used to perform air sampling operations at various stages of the cable under test.

[0102] The cable degassing module is used to degas the sealed cable under test to obtain a degassed cable under test.

[0103] The cable pressure relief module is used to relieve pressure on the degassed cable under test.

[0104] A nitrogen-filled cable module is used to perform nitrogen-filled treatment on a portion of the cable under test obtained from the cable depressurization module, resulting in a nitrogen-filled cable under test.

[0105] The crosslinking byproduct time series data acquisition module is used to perform gas chromatography analysis on the gas sample obtained by the cable gas sampling operation module, and to calculate the concentration of byproduct gas components in the gas sample using the normalization method, so as to obtain the crosslinking byproduct time series data of the cable under test during the degassing process.

[0106] The cable degassing analysis module is used to analyze the degassing degree of the cable under test based on the crosslinking byproduct time series data diagram.

[0107] Example 3

[0108] like Figure 6 As shown, this embodiment provides a computer device, which includes a processor 102, a memory, an input device 103, a display 104, and a network interface 105 connected via a system bus 101. The processor 102 provides computing and control capabilities. The memory includes a non-volatile storage medium 106 and internal memory 107. The non-volatile storage medium 106 stores an operating system, computer programs, and a database. The internal memory 107 provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium 106. When the computer program is executed by the processor 102, it implements the method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production as described in Embodiment 1.

[0109] Example 4

[0110] like Figure 7 As shown, this embodiment provides a storage medium storing a program. When the program is executed by a processor, it implements the method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production as described in Embodiment 1.

[0111] It should be noted that the computer-readable storage medium in this embodiment can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0112] In this embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this embodiment, the computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying a computer-readable program. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable storage medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The computer program contained on the computer-readable storage medium can be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination thereof.

[0113] The computer-readable storage medium described above can be used to write computer programs for executing this embodiment in one or more programming languages ​​or combinations thereof. These programming languages ​​include object-oriented programming languages—such as Java, Python, and C++—and conventional procedural programming languages—such as C or similar programming languages. The program can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0114] In summary, the crosslinking byproduct collection and analysis method of the degassing process in XLPE cable production of the present invention can effectively prevent the diffusion of byproducts during the detection of byproduct concentration by placing the cable under test in a degassing chamber, thereby improving the shortcomings of existing methods such as low sensitivity and large error. At the same time, this method studies the dynamic process, strengthens the monitoring of the residual amount of byproducts during the cable degassing process, provides more comprehensive data, enhances the accuracy and comprehensiveness of the final cable degassing evaluation results, and makes full preparations for the subsequent cable cabling work.

[0115] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for collecting and analyzing crosslinking byproducts during the degassing process in XLPE cable production, characterized in that, Includes the following steps: S1. Before the cable leaves the factory, obtain at least two test cables that have not undergone degassing. The cable under test is an XLPE cable with insulated cores, an inner shielding layer, a main insulation layer, and an outer shielding layer. S2. Set multiple temperature measuring points in the main insulation layer of the cable under test that has not been degassed; A hollow aluminum tube is sleeved onto the cable to be tested after the temperature measuring point is set. The two ends of the hollow aluminum tube are sealed by argon arc welding, and a gas sampling nozzle is set on the hollow aluminum tube to obtain the sealed cable to be tested. S3. Place the sealed cable to be tested obtained in step S2 into the degassing chamber for the first gas extraction operation. After the first gas extraction operation is completed, perform the degassing operation on the cable to be tested after the first gas extraction. During the degassing process of the cable to be tested, perform gas extraction operation on it periodically. After the degassing of the cable to be tested is completed, collect the temperature change data of the main insulation layer of the cable to be tested throughout the entire degassing cycle through the temperature measuring point. S4. Depressurize the degassed test cable obtained in step S3 and divide it into two parts. One part of the test cable is nitrogen-filled, while the other part is left untreated. After periodically sampling the nitrogen-filled test cable and the untreated test cable, the crosslinking byproducts of the degassing process of the test cable production are collected. S5. Perform gas chromatography analysis on the crosslinking byproduct gas samples collected in all gas sampling operations in steps S3 and S4, and calculate the concentration of byproduct gas components in the gas samples using the normalization method to obtain a time series data diagram of crosslinking byproducts in the degassing process of the cable under test, and analyze the degree of degassing of the cable under test based on the time series data diagram of crosslinking byproducts.

2. The method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production according to claim 1, characterized in that, The specific process of step S2 is as follows: First, equally spaced holes are drilled on the surface of the undegassed cable under test. The measuring end of the thermocouple is installed into the main insulation layer along the drilled holes. Holes are also drilled at corresponding positions on the hollow aluminum tube. The drilled hollow aluminum tube is then fitted onto the surface of the cable under test. The compensating end of the thermocouple is then connected to the paperless recorder along the corresponding drilled holes in the hollow aluminum tube. The paperless recorder is placed outside the hollow aluminum tube. Finally, both ends of the hollow aluminum tube are sealed using argon arc welding, and a gas sampling nozzle is installed on the hollow aluminum tube to obtain a sealed cable under test.

3. The method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production according to claim 1, characterized in that, The calculation of the gas sampling cycle for the periodic gas sampling operation performed on the cable under test during the degassing process described in step S3 is expressed as follows: Δt=(L2 / (π 2 D))×ln(1 / (1-r)) Where Δt is the gas extraction cycle, L is the insulation layer thickness in mm, D is the byproduct diffusion coefficient in mm / h, and r is the expected byproduct reduction rate within one gas extraction cycle, 0 < r < 1.

4. The method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production according to claim 1, characterized in that, Before all gas sampling operations in steps S3 and S4, the gas pressure must be measured with a barometer. Then, a fixed amount of gas is extracted each time using an air pump, and the extracted gas is collected as a gas sample into a gas collection bag for labeling and preservation.

5. The method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production according to claim 1, characterized in that, The specific concentrations of the byproduct gas components mentioned in step S5 are as follows: Where, n ik % represents the actual concentration of byproduct gaseous component i, h represents the total number of gas types, and n ik The total amount of substance of the actual gaseous component i of the byproducts.

6. The method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production according to claim 1, characterized in that, The length of the undegassed test cable mentioned in step S1 is at least 3 meters.

7. The method for collecting and analyzing crosslinking byproducts during the degassing process of XLPE cable production according to claim 1, characterized in that, The criteria for evaluating the degree of degassing of the cable under test in step S5 are as follows: According to the data in the time series data diagram of cross-linking byproducts corresponding to the cable under test, if the cable under test meets the following conditions: the content of each cross-linking byproduct is stable in the three gas sampling tests before the end of degassing, and the fluctuation range of the cross-linking byproduct content is less than 10% of the average value of the three gas sampling tests, and the measured cross-linking byproduct content is less than 2% during the nitrogen filling stage of the cable under test, then the cable under test is considered to have been degassed sufficiently; otherwise, the cable under test is considered to have been degassed insufficiently.

8. A system for collecting and analyzing crosslinking by-products during the degassing process in XLPE cable production, used to implement the method for collecting and analyzing crosslinking by-products during the degassing process in XLPE cable production as described in any one of claims 1-7, characterized in that, The system includes: The test cable acquisition module is used to acquire at least two undegassed test cables before the cables leave the factory; the test cables are XLPE cables with insulated cores, inner shielding layers, main insulation layers and outer shielding layers; The cable temperature measurement module is used to set multiple temperature measurement points in the main insulation layer of the cable under test that has not undergone degassing, and to collect temperature change data of the main insulation layer of the cable under test throughout the entire degassing cycle. The cable sealing module is used to attach a hollow aluminum tube to the cable under test after the temperature measuring point is set, and to seal both ends of the hollow aluminum tube by argon arc welding. Finally, an air sampling nozzle is set on the hollow aluminum tube to obtain the sealed cable under test. A sealing inspection module is used to test the sealing performance of the sealed cable under test. The cable air sampling operation module is used to perform air sampling operations at various stages of the cable under test. The cable degassing module is used to degas the sealed cable under test to obtain a degassed cable under test. The cable pressure relief module is used to relieve pressure on the degassed cable under test. A nitrogen-filled cable module is used to perform nitrogen-filled treatment on a portion of the cable under test obtained from the cable depressurization module, resulting in a nitrogen-filled cable under test. The crosslinking byproduct time series data acquisition module is used to perform gas chromatography analysis on the gas sample obtained by the cable gas sampling operation module, and to calculate the concentration of byproduct gas components in the gas sample using the normalization method, so as to obtain the crosslinking byproduct time series data of the cable under test during the degassing process. The cable degassing analysis module is used to analyze the degassing degree of the cable under test based on the crosslinking byproduct time series data diagram.

9. A computer device comprising a processor and a memory for storing a processor-executable program, characterized in that, When the processor executes the program stored in the memory, it implements the method for collecting and analyzing crosslinking byproducts in the degassing process of XLPE cable production as described in any one of claims 1-7.

10. A storage medium storing a program, characterized in that, When the program is executed by the processor, it implements the method for collecting and analyzing crosslinking byproducts in the degassing process of XLPE cable production as described in any one of claims 1-7.

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