炼油厂含氢爆炸性气体混合物的分级

摘要

炼油厂工艺装置在生产过程中会产生大量爆炸危险气体，需要选择合理的防爆电气及工艺设备以保证安全生产。本文对爆炸性气体混合物的分级方法进行了分析，特别是对于IIC级的划分进行了重点论述，根据标准NFPA 497-2008提供的爆炸性混合气体的最大安全试验间隙计算公式进行了统计推算，结合标准IEC60079-20所列物质的最大安全试验间隙，给出了含氢爆炸性混合气体的分级方法，论证了按照氢气体积比25%判断含氢爆炸危险性混合气体是否为IIC级是可行和经济的。解决了业界争议多年的IIB级和IIC级划分的氢气含量百分比的问题，对炼油工程设计有很大的借鉴作用。%Refinery process equipments will produce a large number of explosive gases, so reasonable explosion-proof electrical and process equipments need be chosen to ensure the safety of production. In this paper, grading methods of explosive gas mixture were analyzed and compared, especially the division of IIC grade. Based on the maximum experimental safe gap (MESG) calculation formula for mixture explosive gas in the standard NFPA 497-497and MESG data in standard IEC60079-20, grading method of the explosive gas mixture with hydrogen was concluded. The method to determine IIC grade mixture explosion gas with hydrogen according as the volume of hydrogen is higher than 25% or not is feasible and economic, which can solve the issue how to grade mixture explosive gas with hydrogen.