Experimental Study on Failure Characteristics and Energy Release Evolution of Coal Under Microwave Irradiation
Abstract
1. Introduction
2. Test Methods
2.1. Coal Sample Preparation
2.2. Test Scheme
2.2.1. Experimental Equipment
2.2.2. Experimental Procedure
2.3. Nuclear Magnetic Resonance Principles
2.4. Microwave Irradiation Principles
2.5. Numerical Simulation of Microwave Irradiation
2.5.1. Geometric Model Establishment and Simulation Condition Setting
2.5.2. Characteristics of Temperature Gradient Distribution
3. Experimental Results and Analysis
3.1. Porosity Variation Characteristics Before and After Microwave Irradiation
3.1.1. T2 Spectrum Analysis
3.1.2. Pore Damage Analysis
3.2. Analysis of Damage Quantity of Coal Samples
3.3. Effects of Damage on Mechanical Properties
3.4. Effects of Damage on Energy Characteristics
3.4.1. Variations in Acoustic Emission Parameters in Different Stages
3.4.2. The Evolution Law of Strain Energy in Different Stages
3.5. The Influence of Damage on the Macroscopic Fracture Characteristics of Coal Samples
4. Discussion
4.1. Microwave-Induced Damage Mechanisms: Porosity Development
4.2. Coal Damage Index Caused by Changes in Porosity After Microwave Irradiation
4.3. Evolution of Coal Cracks and Energy Dissipation Characteristics Under Microwave Irradiation
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Type of Sample | Debase Saturated Semaphore | Pore Volume of Coal Sample | Sample Volume/cm3 | Porosity /% | ||
---|---|---|---|---|---|---|
HC1 | Before microwave irradiation | 2227.128 | 0.40 | 29.24 | 1.41 | 0.017 |
After microwave irradiation | 5131.206 | 0.90 | 3.03 | |||
HC2 | Before microwave irradiation | 3022.012 | 0.54 | 31.26 | 1.84 | 0.013 |
After microwave irradiation | 5218.664 | 0.93 | 2.97 |
Microwave Processing | Sample Number | Initial Damage Quantity D | Average Initial Damage D | of Coal Sample |
---|---|---|---|---|
Non-microwaved coal sample | CGN1 | 0.078 | : 0.089 | 0.017 |
CGN2 | 0.089 | |||
CGN3 | 0.099 | |||
Coal sample after microwave treatment | CGY1 | 0.095 | : 0.106 | |
CGY2 | 0.107 | |||
CGY3 | 0.117 |
Index | CGN1 | CGN2 | CGN3 | Average Value | Standard Deviation | CGY1 | CGY2 | CGY3 | Average Value | Standard Deviation |
---|---|---|---|---|---|---|---|---|---|---|
Stress peak value/MPa | 10.95 | 8.98 | 7.59 | 9.17 | 1.69 | 3.49 | 3.15 | 2.26 | 2.97 | 0.64 |
Bursting energy index | 6.25 | 5.27 | 3.51 | 5.01 | 1.39 | 1.95 | 2.05 | 1.01 | 1.67 | 0.57 |
Sample Number | Fissure Compaction Stage | Elastic Stage | Stable Development Stage of Microfractures | Unstable Rupture Development Stage | |
---|---|---|---|---|---|
Duration/s | CGN1 | 41.49 | 79.05 | 9.53 | 25.64 |
CGN2 | 40.06 | 43.52 | 34.93 | 15.50 | |
CGN3 | 43.19 | 24.62 | 37.03 | 9.71 | |
Average value | 41.58 | 49.06 | 27.16 | 16.95 | |
CGY1 | 45.78 | 45.19 | 8.70 | 4.77 | |
CGY2 | 54.49 | 40.17 | 5.25 | 15.74 | |
CGY3 | 43.82 | 27.74 | 10.75 | 16.27 | |
Average value | 48.03 | 37.70 | 8.23 | 12.26 | |
Acoustic emission ringing count | CGN1 | 56,555 | 236,400 | 256,489 | 318,857 |
CGN2 | 9548 | 112,990 | 207,745 | 389,639 | |
CGN3 | 62,724 | 92,853 | 119,251 | 146,340 | |
Average value | 42,942 | 147,414 | 194,495 | 284,945 | |
CGY1 | 163,406 | 466,608 | 523,751 | 615,707 | |
CGY2 | 75,313 | 359,247 | 417,590 | 566,189 | |
CGY3 | 77,774 | 202,745 | 277,911 | 388,395 | |
Average value | 105,498 | 342,867 | 406,417 | 523,430 | |
Acoustic emission energy/aJ | CGN1 | 3.42 × 106 | 3.91 × 107 | 6.33 × 106 | 3.71 × 107 |
CGN2 | 4.32 × 105 | 1.28 × 107 | 2.72 × 107 | 6.34 × 107 | |
CGN3 | 5.21 × 106 | 2.22 × 106 | 2.84 × 106 | 4.17 × 106 | |
Average value | 3.02 × 106 | 1.80 × 107 | 1.21 × 107 | 3.49 × 107 | |
CGY1 | 1.04 × 107 | 3.08 × 107 | 9.04 × 106 | 3.85 × 107 | |
CGY2 | 2.53 × 106 | 3.01 × 107 | 7.28 × 106 | 1.43 × 107 | |
CGY3 | 1.62 × 106 | 6.47 × 106 | 6.18 × 106 | 8.72 × 107 | |
Average value | 4.84 × 106 | 2.25 × 107 | 7.50 × 106 | 4.67 × 107 |
Sample | Index | Fragment Size/mm | Fractal Dimension D | ||||
---|---|---|---|---|---|---|---|
<2 | 2~5 | 5~10 | 10~20 | >20 | |||
CGN1 | Quality/g | 0.44 | 0.95 | 0.48 | 0.73 | 191.25 | 1.33 |
Mass fraction/% | 0.23 | 0.49 | 0.25 | 0.38 | 98.66 | ||
CGN2 | Quality/g | 0.93 | 1.15 | 0.42 | 4.45 | 186.37 | 1.47 |
Mass fraction/% | 0.48 | 0.59 | 0.22 | 2.30 | 96.40 | ||
CGN3 | Quality/g | 1.35 | 3.23 | 5.60 | 16.29 | 170.71 | 1.50 |
Mass fraction/% | 0.68 | 1.64 | 2.84 | 8.26 | 86.58 | ||
CGY1 | Quality/g | 2.32 | 4.18 | 2.00 | 2.64 | 181.59 | 1.78 |
Mass fraction/% | 1.20 | 2.17 | 1.04 | 1.37 | 94.22 | ||
CGY2 | Quality/g | 2.51 | 5.25 | 2.27 | 8.92 | 161.35 | 1.78 |
Mass fraction/% | 1.39 | 2.91 | 1.26 | 4.95 | 89.49 | ||
CGY3 | Quality/g | 2.98 | 3.87 | 3.28 | 7.81 | 170.07 | 1.81 |
Mass fraction/% | 1.59 | 2.06 | 1.74 | 4.15 | 90.46 |
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Ding, C.; Cao, A.; Liu, H.; Wen, Y.; Guo, W.; Shi, Y. Experimental Study on Failure Characteristics and Energy Release Evolution of Coal Under Microwave Irradiation. Appl. Sci. 2025, 15, 9522. https://doi.org/10.3390/app15179522
Ding C, Cao A, Liu H, Wen Y, Guo W, Shi Y. Experimental Study on Failure Characteristics and Energy Release Evolution of Coal Under Microwave Irradiation. Applied Sciences. 2025; 15(17):9522. https://doi.org/10.3390/app15179522
Chicago/Turabian StyleDing, Chuanghong, Anye Cao, Haonan Liu, Yingyuan Wen, Wenhao Guo, and Yang Shi. 2025. "Experimental Study on Failure Characteristics and Energy Release Evolution of Coal Under Microwave Irradiation" Applied Sciences 15, no. 17: 9522. https://doi.org/10.3390/app15179522
APA StyleDing, C., Cao, A., Liu, H., Wen, Y., Guo, W., & Shi, Y. (2025). Experimental Study on Failure Characteristics and Energy Release Evolution of Coal Under Microwave Irradiation. Applied Sciences, 15(17), 9522. https://doi.org/10.3390/app15179522