Study on particle size distribution, microstructure, and water-soluble ion composition of smoke released by typical combustibles in substations

  Objective  To carry out research on the particle size distribution, micro-morphology, and composition characteristics of combustible combustion smoke particles, and comprehensively understand the smoke information of fires.

  Methods  The cable outer sheath, rubber tires, wire insulation layer, insulating cardboard, transformer oil, and fire residue oil at the combustion site of the substation fire were collected. Through combustion simulation experiments, use a particle matter classification sampler to collect the smoke particles released by combustion and analyze the particle size distribution characteristics of different smoke particles and their distribution in different deposition sites of the human respiratory tract. By comparing the scanning electron microscope images of different particle sizes of smoke dust, the micro-morphology and elemental composition of different particle sizes were surveyed.

  Results  Based on ion chromatography analysis, Cl^-emission factor was 0.089 2-1.207 2 μg/g, accounting for 57.3%-67.9% of water-soluble ions, and there were differences in its particle size distribution characteristics between solid and liquid combustibles.

  Conclusions  The smoke particles released by different combustibles were mainly particles with a diameter less than 0.25 μm, and there were differences in Cl^-emission factors. These differences could be used as the basis for evaluating the source of smoke dust and respiratory exposure assessment of personnel at fire scenes.