Underground » Detection and Prevention of Fires and Explosions
A comprehensive research project into mine fires study applying the VENTGRAPH mine fire simulation software, preplanning of escape scenarios and general interaction with rescue responses has been completed. The project relied on substantial mining company and site support to allow the approach to be introduced in the most creditable way. The Australian mining industry is in an improved position in their understanding of mine fires and the use of modern advances to preplan for mine fires and the handling of possible emergency incidents.
The essential work program of the project was built around the introduction of fire simulation computer software and the consequent modelling of fire scenarios in selected mine with different layouts. Some technology transfer at technical seminars has occurred. The theory of fire behaviour and fire control in the underground mine environment is complex. Application of the simulation software package to the changing mine layouts requires experience to achieve realistic outcomes. The research program was managed through a team from the University of Queensland. It has drawn on the experience of overseas experts who provided support to the project, namely Dr Andrzej Wala of the University of Kentucky and Dr Waclaw Dziurzynski from the Polish Academy of Sciences. The commitment of industry bodies with interest in mine fires was vital. Support and advice were sought from the relevant sectors and agencies across state boundaries.
Most Australian mines currently use a ventilation network simulation program. Under the project a small subroutine has been written to transfer the input data from the existing mine ventilation network simulation program "Ventsim" to "Ventgraph". It is necessary to understand the range of effects of mine fires on various mine ventilation systems correctly before the effects of simulation of fire behaviour on the mine ventilation system can be attempted. Case studies demonstrating the possible effects of fires on some typical Australian coal mine ventilation layouts have been examined. Development panel arrangements presents a variety of situations and some cases where reversal of ventilation air may occur have been highlighted. Unstable and dangerous situations may arise under some situations in which there is gas make at the face and a fire occurs.
The importance of understanding complex ventilation networks such as those with diagonal connections has been discussed. It is important to identify and understand their potential effects on the mine ventilation network as the airflow through the diagonal connections could reverse or stop due to the changes in the adjoining branches within the ventilation network. Mining companies need to identify the existing and potential diagonal connections in their ventilation system and analyse how these connections will affect their ventilation system especially in the case of fires. Training is necessary to equip mine ventilation personnel how to identify and minimize diagonal connections in their ventilation system.
Case studies have been developed to examine usage of inertisation tools and particularly application of the Polish developed jet engine unit, the Gorniczy Agregat Gasniczy (GAG). Gorniczy Agregat Gasniczy loosely translates to Mining Apparatus Extinguisher The best surface portal location placement for the GAG for most efficient suppression of a fire and the situation with significant seam gas being emitted on a dipping face have been examined. Operation of an inertisation unit requires preplanning in terms of infrastructure requirements for a surface portal docking station and access for operating personnel, jet fuel, water and other operating requirements.
The aims of the project have been achieved. The Polish fire simulation program VENTGRAPH program has been introduced to the Australian coal industry. Greater understanding of coal mine fire behaviour has been achieved. A sub-program has been written to allow mine network information used for Ventsim to be transferred in a reasonably convenient step to allow input to VENTGRAPH. The industry has been very supportive and case studies of scenario development have been undertaken at four Queensland mines. Application of the program to the industry is an on-going process and other mines in Queensland and NSW are also having fire scenarios developed for their circumstances.
Mine fires are recognized across the world as a major hazard issue. New approaches allowing improvement in understanding their consequences have been developed.