Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology, as a highly selective, interference-resistant, and rapid-response (<1 s) optical gas detection method, demonstrates significant advantages in real-time monitoring of multi-component toxic and hazardous gases (such as CH₄, CO, H₂S, etc.) in coal mines. It is progressively replacing traditional electrochemical sensors and gas chromatography techniques. This paper systematically reviews the key technical pathways, current engineering applications, and future challenges of TDLAS in complex coal mine environments. It highlights the performance differences between Direct Absorption Spectroscopy (DAS) and Modulation Spectroscopy (MS), emphasizing the mainstream role of the WMS-2f/1f normalization method in enhancing trace gas detection sensitivity and anti-interference capabilities. For multi-component detection, the paper thoroughly examines the advantages and disadvantages of time-division multiplexing (TDM) Technology, frequency-division multi-plexing (FDM) Technology, and their hybrid strategy (F-TDM). It also explores the potential of overlapping spectral line separation strategies based on single lasers and machine learning algorithms for achieving low-cost, compact multi-component sensing. Although TDLAS has achieved preliminary applications in duct monitoring and in-situ detection, challenges persist, including nonlinear responses to high-concentration gases, laser costs, system complexity, and adaptability to extreme environments (high humidity, high dust, strong vibration). Future research should focus on developing high-concentration correction algorithms, low-cost laser sources, enhanced environmental robustness, and multi-technology integration to advance the comprehensive application of TDLAS in intelligent gas safety monitoring systems for mining environments.

Quantitative design of the optimal gas extraction engineering parameters has always been a key scientific problem to meet the predrainage target of the coal seam, which is paid great attention to and urgently expected to solve for the gas extraction engineering of coal mine. In this paper, the governing equation of the evolution of coal seam gas content is established under the interference and cooperation of gas extraction by boreholes, and the calculation formula of gas cooperative efficiency is defined. Based on gas-air mixed flow, a multifield coupling 3d model of coal gas extraction using boreholes was developed. The content, method, and principle of optimal spacing parameter design of extraction borehole were proposed, and the constraint conditions and objective function of optimal design were constructed. The flow characteristics of gas extraction using boreholes in the coal seam area and the influence of different parameters on gas extraction effect are studied. The cooperative and competitive behaviors of gas extraction by boreholes in coal seam are revealed. The results show that borehole spacing, seam fracture permeability, and gas adsorption constant have significant effects on the synergistic and competitive effects of gas extraction, while the negative pressure of gas extraction and coal matrix permeability have little effects, but the negative pressure of gas extraction has great effects on gas extraction concentration. Finally, Comsol With Matlab is used to solve the multiconstraint nonlinear optimization problem of gas drainage engineering parameters along coal seam in 18401 working face of Tunlan Coal Mine. The effect of actual gas extraction investigation is very remarkable, which provides a quantitative calculation basis for scientific gas extraction in coal mine.

For a long time, the serious mismatch between negative pressure and drainage parameters of underground gas drainage has been the main reason for the standing engineering problems in coal mines, such as low gas drainage concentration, fast decay, and low-utilization rate. Aiming at these problems, an innovative method by adding micro-frequency conversion drainage pumps and electronically controlled valves at the key nodes of the conventional pipe network system of gas drainage and the joint quantitative regulation of underground regulation facilities and surface drainage pumps based on the intrinsic correlation between the drainage parameters and negative pressure is proposed in this paper to solve the difficulty of how to regulate increasing pressure or resistance in the on-site gas-drainage system and to realize energy matching in the whole drainage system on demand. For this method, the study further defines the safety and efficiency criteria of gas drainage, proposes the adaptive control strategy of gas-drainage parameters, and establishes the adaptive control model based on particle swarm optimization. The model took the safety and efficiency criteria of gas drainage as the constraint conditions and the maximum gas-drainage flow or concentration as the objective function to adaptively adjust the operating conditions of drainage pumps, micro-frequency conversion drainage pumps, and electric control valves to realize the adaptive regulation of gas-drainage parameters. Finally, based on the adaptive control strategy and model of gas-drainage parameters, the numerical simulation research was carried out through Comsol with Matlab. The results show that the gas-drainage concentration and high-concentration drainage period can be increased many times, and the adaptive drainage parameters of valves and micro pumps can be adjusted intelligently, which provides a theoretical basis for the intelligent field implementation of gas.