1:40 scaled physical model of a longwall coal mine to investigate mine ventilation and the formation of explosive gas zones, A

Abstract

The formation of explosive gas zones (EGZs) is a critical problem in longwall coal mines. The investigation of how EGZs might form currently relies on Computational Fluid Dynamics (CFD) models, which have limitations around long solution times and availability of certain validation data in a longwall mine. Physical, scaled models are an alternative to investigating dynamic fluid behavior under complex scenarios that range from aircraft design to airway investigation. Scaled modeling requires extensive dimensional analysis evaluation to replicate complex airflow phenomena adequately. This work presents design and manufacturing considerations to build a 1:40 scaled version of a longwall coal mine to investigate mine ventilation strategies and the formation of EGZs. The physical model presented is the only known scaled model of a longwall coal mine built on a modular design and capable of simulating different ventilation strategies, longwall face advance, and shearer motion. The physical model has a mine-wide atmospheric monitoring system (AMS) capable of measuring airflow speed and gas concentrations in the air courses, longwall face, and gob region. Initial experimental data results prove the model to be consistent with CFD models and published ventilation data of longwall coal mines. The physical model captured the trends of flow leakage and simulated methane accumulation across the longwall face compared to published data of actual mines and CFD models.