Experimental investigations on the deflagration explosion characteristics of different DME–LPG mixtures

The deflagration explosion characteristics of premixed dimethyl ether (DME)–liquefied petroleum gas (LPG)–air mixtures with different equivalence ratios and DME to DME–LPG mixture ratios were investigated using a confined chamber with a length and cross section of 500 mm and 100×100 mm2, respectively. Six fuels including 100% LPG, 100% DME and four different DME–LPG mixtures with varying DME ratios (the DME was increased incrementally by 20%) were used in the experiments, and the effects of the equivalence ratio and DME ratio on the flame speed and overpressure were determined. As the equivalence ratio and DME to DME–LPG mixture ratio were increased, an increase in the flame speed and overpressure was observed. The flow velocity vectors of unburnt mixtures ahead of the propagating flame in the wake of an obstacle were sensitive to the DME ratio. Moreover, the flame speed, flow velocity vector and overpressure of 100% LPG and 20% DME were similar. Thus, 20% DME and 100% LPG present similar explosion hazards.

► The deflagration explosion characteristics of different DME–LPG mixtures were investigated.
► As the DME to DME–LPG mixture ratio increased, the flame speed and overpressure increased.
► The flame speed, flow velocity vector and overpressure of 100% LPG and 20% DME were similar.
► 20% DME and 100% LPG present similar explosion hazards.