Development of test equipment based on isothermal difference to determine characteristic parameters involved in coal spontaneous combustion

ABSTRACT

The characteristic parameter test is the basis for the prevention and control of the spontaneous combustion of coal; however, there are some deficiencies in many test methods at present, such as large amounts of experimental coal, long testing periods, and not being able to fully reflect the oxidation and exothermic characteristics of coal itself. This study has independently designed and developed a test device to determine the characteristic parameters of the spontaneous combustion of coal based on the isothermal difference leading method. Through experimental testing of different coal samples using 3, 7, 10, 15, and 20°C as the leading values, it was determined that the lead error was less affected by the lead value, and that it had a direct relationship with the temperature control program. The difference in the lead value did not change the linearity; however, it changed the periodicity. The optimal leading temperature difference was determined as 15°C. In a comparison experiment using a large-scale spontaneous combustion test bench, the heating law of the spontaneous combustion of coal was consistent. The experimental system based on isothermal difference leading achieved the adiabatic oxidation of coal up to a maximum point, which could better reflect the low-temperature oxidization of coal, reduce the amount of experimental coal needed, and improve the experimental periodicity. Additionally, it considerably improved experimental efficiency and provided a new technical approach for the prevention and control of the spontaneous combustion of coal.

KEYWORDS:

• Spontaneous combustion of coal
• isothermal difference leading
• leading value
• characteristic parameters
• experimental efficiency

Acknowledgments

We appreciated the co-authors for their guidance on experimental design. Thanks for their contribution to this study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the National Natural Science Foundation of China (grant numbers 51904234).