Improving methods for calculating the equivalent pressure of jet fans in large-section mine workings

Abstract

Relevance. The need to improve methods for calculating the operating parameters of jet fans in mine workings. The use of jet fans operating without air stopping is a promising option for increasing the efficiency of ventilation of large-section mine working systems. Operational analysis of the effectiveness of the selected parameters of jet fans and mixing chambers is possible only if there are sufficiently universal and accurate methods for calculating equivalent characteristics. While the approaches existing today have, as a rule, only one of the above properties. Aim. To determine the patterns of changes in the aerodynamic parameters of the air flow as it moves through a mine working with the jet fan operating without air stopping. Objects. Air flows generated in a large-section mine working as a result of the operation of the jet fan with a mixing chamber. Methods. Three-dimensional numerical simulation of steady-state turbulent air flow in a mine working, comparative analysis of calculation results for different locations of the jet fan, comparative analysis of numerically calculated equivalent characteristics of the jet fan with an analytical formula. Results. The authors have determined the patterns of changes in mechanical energy and static pressure of the air flow as it moves along the mine working. Multiparameter numerical simulation for various airflow rates at the entrance to the mine working made it possible to obtain equivalent pressure characteristics of the VM-8 jet fan with a mixing chamber, which can be used in one-dimensional calculations of the steady-state distribution of flow rates in the mine ventilation networks. A comparative analysis of simulation data with a known analytical dependence of the pressure drop made it possible to determine the directions for further improvement of analytical methods for describing air flow in mine workings with jet fans equipped with mixing chambers.