Work

Study on the Spatiotemporal Evolution Characteristics of Gas Pressure Field during Gas Injection into Loaded Coal

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide To investigate the spatiotemporal distribution characteristics of gas pressure inside coal during gas injection, this study utilized N 2 and CO 2 as the injection source gases. By combination of experimental research with theoretical analysis, the internal gas pressure variation in coal during the injection process was analyzed in-depth. The differences in gas pressure between the two source gases were compared, and the influence of strong-adsorption and weak-adsorption gases on the internal gas pressure was explored. The results show that the distribution of the gas pressure within the coal during injection is not uniform. Under a constant injection pressure of 0.7 MPa, the maximum pressure difference is approximately 0.17 MPa. The internal gas pressure exhibited distinct variation characteristics during N 2 and CO 2 injection. Due to the weaker adsorption of N 2, it mainly exists in a free state after entering the coal. Thus, the internal gas pressure in the coal rises rapidly at the early stage of injection but then gradually decreases as some N 2 exits the outlet. Conversely, CO 2 quickly transitions to an adsorbed state after entering the coal, leaving little free gas in the coal. Combined with the outflow of some gas from the outlet, the internal gas pressure initially shows a downward trend during the early stage of CO 2 injection. Later, as CO 2 gradually reaches adsorption saturation, the gas pressure begins to increase slowly. These findings provide a basis for selecting optimal injection source gases and offer a reference for addressing safety issues during the gas injection process.

Source: ACS Omega

DOI: 10.1021/acsomega.4c10880

Authors: Kan Zhou, Jinfeng Guan, Xionggang Xie, Huaiguang Guo

Institutions: Guizhou Normal University, Guizhou University of Engineering Science, Guizhou University, China Coal Technology and Engineering Group Corp (China), State Key Laboratory of Coal Mine Safety Technology

Language: English

Topic: Coal Properties and Utilization

Subfield: Ocean Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funder: National Natural Science Foundation of China