为确定含二氧化碳天然气云团扩散的危险区域范围,借助数值模拟方法建立了含二氧化碳天然气云团扩散模型,详细研究了含二氧化碳天然气云团扩散过程,确定了包括窒息和燃爆在内的2种危险区域。研究结果表明,含二氧化碳天然气云团扩散中燃爆区域呈不规则圆环状分布,燃爆区域的横风向尺度变化不大,而平行于风向的方向变化较大。无论横风向还是顺风向,燃爆区域尺度随时间的变化都呈开口朝下的抛物线形分布。高含二氧化碳天然气云团扩散后形成的燃爆区域无论从时间还是空间尺度看,波及的范围都远小于窒息性危险区域。

The explosion characteristics and hazards caused by dispersion of the natural gas containing carbon dioxide are concerned about. In order to confirm the hazard zone determination during the dispersion of natural gas containing carbon dioxide, explosion characteristics and the accuracy evaluation for the numerical model, mechanism of the puff dispersion and dispersion issues caused by blowout were investigated by numerical simulation methods. A dispersion model of natural gas containing carbon dioxide was set up, and the dispersion evolvement was researched in detail, furthermore, the hazard zone concluding asphyxiation and explosion or flammability is defined. The numerical simulation results show that the flammability zone caused by the puff dispersion of the natural gas containing carbon dioxide takes on an irregular cirque distribution. Along-wind variation of flammability-zone dimension is larger than that for crosswind. For both cases of along-wind and crosswind, the distribution of variations of flammability zone with time presents the shape of parabola whose peak point is up. Besides, it does not matter to judge explosive zone based on time or on space, the affected area for flammability zone is way smaller than that for the asphyxia zone.