Experimental investigation on flame characteristics in a linear array of dual spill fire

Abstract

In the process of petroleum production and transportation, a porous leakage accident can easily lead to combustion behaviors such as fire merging, resulting in more severe consequences. This study explores the combustion characteristics of merging spill fires through experimental investigations, incorporating dual leakage holes with varying spacing to examine their impact on the combustion process. The experimental results suggest that the flame height undergoes a pattern of initial decrease followed by an increase with the gradual expansion of leakage spacing, owing to the coupling effects of air entrainment and thermal radiation feedback within the additional entrainment zone. Based on the developmental pattern of flames with respect to leakage spacing, this study categorizes the dual spill fire into three states: which are: (1) full merging state, (2) intermittent merging state, and (3) separation state. The flame height prediction model is established for different merging states, considering parameters such as the fuel discharge rate and the leakage spacing of dual spill fire. The experiment reveals that the flame pulsation frequency (FPF) of the spill fire follows the pattern observed in pool fire FPF, and an FPF model for dual spill fire in all states is obtained through the fitting. Finally, the coupled heat transfer between dual fire sources is considered, and a burning rate model for dual spill fire in intermittent merging states is established.