Thermo-fatigued Coal

Marked Crack Growth

Coal for enhanced gas extraction, subjected to cyclic thermal shock, developing dense microcracks and interlayer debonding to effectively improve permeability.

Qin, Lei · Niandong, Chen · Wang, Weikai · Meiling, Xiong · Han, Wang · Zengning, Huang

Engineering Failure Analysis 2026

Specifications

Cold Temperature

{'zh': '-38', 'en': '-38'} °C

Hot Temperature

{'zh': '120', 'en': '120'} °C

Advantages

Enhanced Permeability

Cyclic thermal shock induces thermal fatigue, interlayer debonding, and microcrack coalescence, forming an effective flow network that improves coal permeability.

Water Saturation Buffering

Water-saturated coal exhibits a significant thermal buffering effect, with reduced temperature oscillation amplitudes due to the high heat capacity and phase-change behavior of pore water.

Thermal Stress Concentration

Cyclic cooling and heating generate intense transient thermal stress gradients, leading to localized stress concentration and subsequent structural fragmentation.

Applications

• Coal Permeability Enhancement：Generate microcrack networks via thermal fracturing to boost permeability for gas migration.
• Mine Gas Extraction：Enhance coal permeability to improve gas extraction efficiency and reduce time and cost.
• Rock Thermal Fracturing：Utilize cyclic thermal shock to induce controlled fracturing, providing data for thermal fracturing applications.