Experimental Study on Explosion Characteristics of Ultra-Low Concentration Methane Mixed with Dimethyl Ether

ABSTRACT

Low-concentration methane accounts for the most massive percent of coal mine methane (CMM). Reasonable utilization of low-concentration methane, especially the ultra-low concentration methane (less than 5%), is of great significance for resource conservation and environmental protection. Therefore, a reasonable utilization method of ultra-low concentration methane (ULCM) was proposed. The main idea is to add combustible substances, such as dimethyl ether (DME), into ULCM to promote its combustion and explosion. The experimental investigations on the explosion parameters of ULCM mixed with DME were conducted in a horizontal explosion pipeline. The results suggested that the addition of DME can promote the combustion and explosion of ULCM. The maximum values of v and P_max appear in the equivalence ratio of 1.1–1.3, which are slightly higher than the values at stoichiometric concentration because of the transient effect of the explosion pipeline. The results provide a reference for selecting optimum mixing concentration in the utilization process of ULCM mixed with combustion supporting agent. The researches offer a feasible method for the utilization of ULCM, which is of great significance for energy conservation and emission reduction of CMM.

KEYWORDS:

• Ultra-low concentration methane
• dimethyl ether addition
• maximum explosion pressure
• flame propagation velocity

Acknowledgments

This work was financially supported by the Open Fund of Key Laboratory of Mine Disaster Prevention and Control in Hebei Province, North China Institute of Science and Technology [KJZH2017K01], the opening project of State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology) [KFJJ21-05M], Leading Talents in Science and Technology Innovation under the Ten Thousands Program [W02020049], National Natural Science Foundation of China [51974322], International Clean Energy Talent Program [201902720011], the Fundamental Research Funds for the Central Universities [2009KZ03], Natural Science Foundation of Xinjiang Uygur Autonomous Region [2019D01A33].

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [51974322]; Natural Science Foundation of Xinjiang Uygur Autonomous Region [2019D01A33]; Leading Talents in Science and Technology Innovation under the Ten Thousands Program [W02020049]; the opening project of State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology) [KFJJ21-05M]; International Clean Energy Talent Program [201902720011]; the Fundamental Research Funds for the Central Universities [2009KZ03]; the Open Fund of Key Laboratory of Mine Disaster Prevention and Control in Hebei Province, North China Institute of Science and Technology [KJZH2017K01].