Numerical Simulation Of Jet For Hydraulic Flushing And Study Of Coal Breaking Mechanism In Coal

Our coal mine safety situation is more serious, coal disaster has become an important influencing factor for threatening national energy security, in which, coal and gas outburst is the worst natural disaster in underground coal mine. In order to effectively prevent coal and gas outburst accident to occurred, hydraulic flushing technology is an effective anti-conflict rapid elimination penetration outburst. Therefore, based on theoretical and experimental research in paper, we have developed special nozzle of hydraulic flushing, Then, jet of hydraulic flushing was simulated, finally, studyed coal breaking mechanism of hydraulic flushing.The main contents of this paper included the following aspects:1. Nozzle types and parameters in the effect of jet characteristics have been analyzed, hydraulic flushing nozzle structure and nozzle body has been designed;2. Internal flow field of hydraulic flushing nozzle body and Jet flow field of nozzle have been simulated by fluent, and, jet hitting power, jet target distance and flushing radius have been simulated calculation.3. Hydraulic flushing field test has been conducted in Yian Coal and Xinan Coal, the result show that test flushing radius higher than the simulative calculation result, the simulative calculation results has guiding significance for the field test.4. Coal breaking mechanism of hydraulic flushing has been researched and analise -d, derived hydraulic flushing process, including breaking cracks, water wedge effect, the surface washed for three mechanisms.It used theoretical research, numerical simulation and experimental validation in this paper study. Internal flow field of hydraulic flushing nozzle body and Jet flow field of nozzle have been simulated, the process of breaking coal of hydraulic flushing was revealed deeper. Jet hitting power, jet target distance and flushing radius have been simulated, the simulation results were consistent with the experimental data.The simulative calculation resultshas certain directive significance and reference for extension and application of hydraulic flushing outburst prevention technique.