Optimization of wind-and-water coordinated dust reduction device for coal mine return airway based on CFD technology

Abstract

High-concentration respirable dust is generated in fully mechanized mining faces, causing health hazards to operators in return airways. To effectively solve this problem, we developed a wind-and-water coordinated dust reduction device. Firstly, the effectiveness of the numerical simulation was validated through spray experiments. Next, the orthogonal experiment method was employed using software such as Fluent and CFD-Post to conduct numerical simulations. This enabled the analysis of the influence of the fan airflow rate (Q), spray pressure (Pw), and nozzle diameter (D) on the coverage capability of the return air roadway and the distribution pattern of the mist field. The results of the numerical simulations indicated that the optimal combination of parameters was Q = 500 m3/min, D = 1.6 mm, and Pw = 5 MPa. Through field application and actual measurement in the return air tunnel of 117 fully mechanized mining face of Jinjitan Coal Mine, the average dust reduction efficiency reaches 91.05%. After dust reduction, the respiratory dust concentrations in the return airway at 20 m, 50 m and 80 m from the air inlet of the return airway are 0.214 mg/m3, 0.172 mg/m3 and 0.153 mg/m3 respectively, which effectively solves the problem of dust pollution in the return airway and reduces dust harm.