Aging Performance and an Improved Evaluation Method for PE80 and PE100 Pipelines for Urban Gas
Abstract
:1. Introduction
2. Accelerated Aging Experiment
2.1. Sample Tube Preparation
2.2. Aging Experimental Process
3. The Aging Status of PE Pipes
3.1. OIT Tests
3.2. Results and Comparison
4. Aging Rate Calculation Model
4.1. Aging Rate Calculation Results
4.2. The Modified Calculation Model
5. Conclusions
- The aging experimental results of PE pipes are closer to the actual performance than those obtained from specimens. The aging process can be simulated with different pipe types, diameters, and pressures according to this method. The aging properties of PE pipes can be well characterized by the OIT value of the materials.
- In the aging experiments mentioned in this paper, the effects of pressure, temperature, diameter, and material types on the aging of PE pipes are considered. Based on the Arrhenius formula, the aging reaction rate at room temperature (service temperature) can be calculated under different conditions.
- Comparing the reaction rate coefficients, the diffusion ability of antioxidants in PE pipes enhances as the pressure increases. The antioxidant content is higher in PE pipes with a bigger diameter and wall thickness (when the SRD is constant) and the anti-aging ability is stronger. When the wall thickness doubles, the aging rate decreases about half of the rate under no pressure conditions.
- The anti-aging ability of PE100 is stronger than PE80. The aging life of PE100 is twice as much that of PE80 at room temperature.
- Based on the Arrhenius formula, the evaluation of the aging status can be extended. Combined with the aging experimental results of PE pipes, an improved aging evaluating method considering wall thickness is proposed in this paper, which can be a support for subsequent model improvements.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Aging Type | Mechanism | Description |
---|---|---|
Photo-oxidative | Photodegradation | The polymer chains will break down under prolonged exposure to ultraviolet (UV) light, causing surface embrittlement and discoloration and impacting resistance reduction. |
Thermo-oxidative | Chain Scission and Crosslinking | The polymer chains will break or crosslink in an environment with oxygen, which reduces the flexibility and strength of the PE pipe. |
Stress Cracking | Crack Initiation and Propagation | Micro-cracks on a PE pipe may occur in service, which will grow under mechanical stress. |
Temp/°C | Pressure/MPa | Aging Times | ||||
---|---|---|---|---|---|---|
1st/h | 2nd/h | 3rd/h | 4th/h | 5th/h | ||
80 | 0 | 0 | 144 | 288 | 576 | 864 |
0.2 | 0 | 144 | 288 | 576 | 864 | |
0.4 | 0 | 144 | 288 | 576 | 864 | |
90 | 0 | 0 | 96 | 192 | 288 | 384 |
0.2 | 0 | 96 | 192 | 288 | 384 | |
0.4 | 0 | 96 | 192 | 288 | 384 | |
100 | 0 | 0 | 24 | 48 | 96 | 192 |
0.2 | 0 | 24 | 48 | 96 | 192 | |
0.4 | 0 | 24 | 48 | 96 | 192 | |
110 | 0 | 0 | 8 | 16 | 32 | 72 |
0.2 | 0 | 8 | 16 | 32 | 72 | |
0.4 | 0 | 8 | 16 | 32 | 72 |
Temp/°C | Time/h | OIT/min | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
PE80 DN63 | PE100 N63 | PE80 DN110 | ||||||||
0 MPa | 0.2 MPa | 0.4 MPa | 0 MPa | 0.2 MPa | 0.4 MPa | 0 MPa | 0.2 MPa | 0.4 MPa | ||
80 | 0 | 88.5 | 88.5 | 88.5 | 87.3 | 87.3 | 87.3 | 88.5 | 88.5 | 88.5 |
144 | 82.3 | 79.9 | 78.4 | 82 | 79.8 | 79.2 | 84.4 | 84 | 83.9 | |
288 | 78.1 | 76.7 | 74.6 | 79.7 | 78.2 | 77.8 | 82.3 | 82.1 | 82 | |
576 | 76 | 74 | 71.2 | 78.2 | 75.8 | 74.6 | 80.1 | 80 | 78.1 | |
864 | 73.8 | 70.1 | 65.4 | 76.6 | 74 | 71 | 78.9 | 76.8 | 75.4 | |
90 | 0 | 88.5 | 88.5 | 88.5 | 87.3 | 87.3 | 87.3 | 88.5 | 88.5 | 88.5 |
96 | 81.2 | 80 | 79 | 83.2 | 82.7 | 82.6 | 85.1 | 84.4 | 83.8 | |
192 | 80.3 | 78.1 | 75.7 | 82.3 | 78.6 | 77.8 | 83 | 82.5 | 82.2 | |
288 | 77.9 | 76.7 | 74.8 | 80.5 | 77.4 | 75.8 | 81.4 | 80.2 | 79.5 | |
384 | 76.7 | 74.7 | 73.3 | 77.1 | 74.8 | 72 | 79.4 | 78 | 76.5 | |
100 | 0 | 88.5 | 88.5 | 88.5 | 87.3 | 87.3 | 87.3 | 88.5 | 88.5 | 88.5 |
24 | 86.1 | 84.3 | 83.3 | 84.8 | 82.8 | 81.9 | 85 | 84.5 | 83.7 | |
48 | 83.3 | 82.4 | 79.9 | 82 | 79.2 | 80.3 | 83.8 | 83 | 82.5 | |
96 | 80.2 | 77.2 | 76.3 | 79.8 | 77.2 | 77 | 83.2 | 82.3 | 80.5 | |
192 | 78.5 | 76.3 | 73.4 | 77.8 | 75 | 73.8 | 81 | 79.4 | 78 | |
110 | 0 | 88.5 | 88.5 | 88.5 | 87.3 | 87.3 | 87.3 | 88.5 | 88.5 | 88.5 |
8 | 85.8 | 85.6 | 85.4 | 84.6 | 83.9 | 83.6 | 85.6 | 84.7 | 83.9 | |
16 | 85.6 | 83.1 | 82 | 83.1 | 81.5 | 80.1 | 85.2 | 84.2 | 83.3 | |
32 | 83.5 | 81.9 | 78.6 | 82.2 | 79.8 | 78.5 | 83.5 | 83.4 | 82.3 | |
72 | 80.6 | 79.1 | 76.3 | 80.1 | 77.8 | 74.5 | 82 | 80.1 | 78.3 |
Pressure/MPa | Temp/°C | K | ||
---|---|---|---|---|
PE80 DN63 | PE100 DN63 | PE80 DN110 | ||
0 | 110 | 0.00118 | 0.00103 | 0.000911 |
100 | 0.0006 | 0.000568 | 0.000385 | |
90 | 0.000341 | 0.000293 | 0.000261 | |
80 | 0.000191 | 0.000133 | 0.000123 | |
0.2 | 110 | 0.0012 | 0.0014 | 0.00116 |
100 | 0.000739 | 0.000707 | 0.000478 | |
90 | 0.000369 | 0.000391 | 0.000316 | |
80 | 0.000212 | 0.000165 | 0.000148 | |
0.4 | 110 | 0.00193 | 0.00198 | 0.00142 |
100 | 0.000896 | 0.000786 | 0.000567 | |
90 | 0.000449 | 0.000491 | 0.000358 | |
80 | 0.00031 | 0.000211 | 0.000176 |
Pressure/MPa | K | ||
---|---|---|---|
PE80 DN63 | PE100 DN63 | PE80 DN110 | |
0 | 2.19655 × 106 | 9.02178 × 107 | 1.10495 × 106 |
0.2 | 2.48867 × 106 | 9.68853 × 107 | 1.15063 × 106 |
0.4 | 2.93855 × 106 | 1.05662 × 106 | 1.21285 × 106 |
PE80 DN63 | PE80 DN110 | |
---|---|---|
en/mm | 5.8 | 10 |
A | 0.970515076 | 0.981791678 |
E0/J·mol−1 | 67,611.62464 | 71,869.73828 |
B | 1,889,022.391 | 5,392,124.386 |
α | 46.2374 | 107.85093 |
β | 0.22897 | 0.38765 |
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Lin, N.; Sun, X.; Sun, M.; Li, X.; Liu, C.; Chen, S.; Meng, T. Aging Performance and an Improved Evaluation Method for PE80 and PE100 Pipelines for Urban Gas. Appl. Sci. 2024, 14, 9941. https://doi.org/10.3390/app14219941
Lin N, Sun X, Sun M, Li X, Liu C, Chen S, Meng T. Aging Performance and an Improved Evaluation Method for PE80 and PE100 Pipelines for Urban Gas. Applied Sciences. 2024; 14(21):9941. https://doi.org/10.3390/app14219941
Chicago/Turabian StyleLin, Nan, Xingze Sun, Ming Sun, Xiaolong Li, Changzheng Liu, Shan Chen, and Tao Meng. 2024. "Aging Performance and an Improved Evaluation Method for PE80 and PE100 Pipelines for Urban Gas" Applied Sciences 14, no. 21: 9941. https://doi.org/10.3390/app14219941
APA StyleLin, N., Sun, X., Sun, M., Li, X., Liu, C., Chen, S., & Meng, T. (2024). Aging Performance and an Improved Evaluation Method for PE80 and PE100 Pipelines for Urban Gas. Applied Sciences, 14(21), 9941. https://doi.org/10.3390/app14219941