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RISS 인기검색어
- 검색키워드
- 저자 : Rickard Hansen (검색결과 2 건)
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Modelling temperature distributions and flow conditions of fires in an underground mine drift
Rickard Hansen 한국자원공학회 2020 Geosystem engineering Vol.23 No.6
An analysis on the modelling of fire gas temperatures and fire gas velocities in a mine drift with longitudinal ventilation is conducted. A computational fluid dynamics (CFD) model and a number of empirical correlations are validated against the results from two full-scale fire experiments in a mine drift. During the analysis it is found that the upper level (ceiling) fire gas temperature at 35 and 50 m from the fire is well fitted when comparing the results from the CFD modelling with the experimental results. The fire gas temperatures at the lower level are found to be over predicted by the CFD model. The ceiling fire gas temperatures directly above the vehicles are over predicted in one case and under predicted in the other case by the CFD model. The empirical models are found to over predict the average fire gas temperature during extensive parts of the fires. The fire gas velocities at the higher section are found to be under predicted and the fire gas velocities at the lower section are over predicted by the CFD model. Future studies should be aimed at developing empirical models for mining applications as well as validating developed CFD models.
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The onset of extreme fire behaviour in a mine drift
Rickard Hansen 한국자원공학회 2018 Geosystem engineering Vol.21 No.5
The onset of extreme fire behaviour in a mine drift with longitudinal ventilation was analysed. A fire in a mine drift with continuous fuel load, involving several separate fires may lead to flames tilted horizontally and filling up the entire cross section. This will lead to earlier ignition, higher fire growth rate, higher fire spread rate and a severe fire behaviour. The focus has been on what changes take place at the onset and signs of the impending phenomenon. It was found that the fire gas temperature at the ceiling level provided a poor indicator. At the downstream far-field region of the fire, the sudden temperature increase at the lowest levels of the cross section and the sudden increase in flow velocities would provide signs of extreme fire behaviour. The corresponding full-scale heat release rates of the experiments at the onset of extreme fire behaviour were found to be very high for mining applications but not necessarily for tunnel fires. The heat release rate threshold for a mine drift with smaller cross-sectional dimensions would decrease considerably, increasing the likelihood of occurrence. The distance between the fuel items will play an important role during the initiation of horizontal flames.
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