Pre-Crosslinked Cable Insulation Aging for Storage Life Detection
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Solution Overview
Problem
There is no well-proven method for detecting the activity and storage life of pre-crosslinked materials used for insulation in high-voltage alternating-current cables, which affects the performance of the insulation layers due to varying DCP content over time.
Innovation Solution
A method involving tableting, measurement of crosslinking and mechanical properties, and accelerated aging tests at controlled temperatures to determine the storage life of pre-crosslinked materials, using equations to calculate decomposition rates and half-life periods of the crosslinking agent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If accelerated aging test is performed on pre-crosslinked material to determine storage life, then accurate assessment of insulation performance is achieved, but test time and material consumption increase
Solution Approach 1:
The patent applies parameter changes by conducting accelerated aging tests at elevated temperatures (e.g., 70°C, 80°C, 90°C) to speed up the decomposition process of the crosslinking agent. By changing the temperature parameter, the test achieves in compressed time the effects that would otherwise require years of natural storage aging, thus resolving the contradiction between measurement accuracy and test time
Solution Approach 2:
The patent performs preliminary actions by conducting tableting and measuring crosslinking degree and mechanical properties on unaged pre-crosslinked material before the aging test. This establishes baseline reference data that enables comparison with aged samples, allowing accurate determination of storage life without needing to conduct the full aging process in real-time conditions
2Measurement precision
If accelerated aging test is performed on pre-crosslinked material to determine storage life, then accurate assessment of insulation performance is achieved, but material consumption increases
Solution Approach 1:
By changing the temperature parameter to elevated levels during accelerated aging tests, the patent achieves equivalent aging effects with significantly reduced material consumption. The high-temperature environment accelerates the decomposition of the crosslinking agent, allowing accurate storage life assessment using smaller, fewer samples compared to traditional long-term natural aging methods
3Productivity
If DCP content is maintained in pre-crosslinked material for long storage life, then crosslinking efficiency is improved, but spontaneous decomposition occurs during storage reducing DCP content
Solution Approach 1:
The patent applies feedback by measuring the crosslinking degree and mechanical properties of pre-crosslinked material at different storage times and temperatures, then using this data to determine the actual storage life. This feedback mechanism allows identification of the optimal storage duration before DCP decomposition significantly impacts crosslinking efficiency, enabling timely use of material while maintaining productivity
Solution Approach 2:
The patent changes the temperature parameter during storage to accelerate decomposition for testing purposes, and uses this data to establish storage life parameters. By understanding how temperature affects DCP stability through parameter changes, the patent determines optimal storage conditions and timeframes that balance crosslinking efficiency with compositional stability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for efficient determination of the storage life of pre-crosslinked materials, reducing test time and material consumption while ensuring accurate assessment of insulation performance.
Implementation Method 1
During storage of the pre-crosslinked granules before being used for cable manufacturing, an amount of DCP is spontaneously decomposed
Implementation Method 2
heating the pre-crosslinked material at a predetermined temperature for a predetermined time period to obtain a fast-aged pre-crosslinked material
Implementation Method 3
free radicals are generated by thermal decomposition of a peroxide crosslinking agent, and are used to crosslink polyethylene having a linear structure into crosslinked polyethylene having a network structure
Data Source
AI summary
A method for detecting a storage life of a pre-crosslinked material is provided. Tableting is performed on an unaged pre-crosslinked material to obtain crosslinked polyethylene. A crosslinking degree and a mechanical property of the crosslinked polyethylene are measured to obtain reference data. The pre-crosslinked material is heated to obtain a fast-aged pre-crosslinked material. The crosslinking degree and mechanical property of crosslinked polyethylene obtained from the fast-aged pre-crosslinked material are measured to obtain measurement results, which are compared with the reference data. If comparison results all fall within corresponding ranges, the time period of heating is increased by a step to repeat the above steps until the comparison results do not all fall within the corresponding ranges. A result obtained by subtracting the step from the time period of heating is converted into a time period of storage at the room temperature.