含CO_2天然气燃烧爆炸特性实验研究

Experimental studies on fire and explosion characteristics of natural gas with carbon dioxide

我国已开始开发含CO2酸性天然气气田,此类气田的开发要求同时重视天然气的火灾爆炸特性和CO2的窒息危险性,如何确定CO2含量阈值浓度,从而制订相应的防护措施具有重要现实意义。为此,运用实验手段研究了含CO2天然气的爆炸极限,得到了CH4、空气及CO2三种组分气体爆炸范围图。研究表明:当泄漏天然气与空气的混合物中CO2体积分数达到13.86%,CH4体积分数为7.48%时,CH4在此混合气体中的爆炸下限与上限重合。当泄漏天然气与周围空气的混合物中CO2体积分数超过13.86%时,应重点考虑CO2的窒息危害,而在此浓度以下时,则应着重考虑天然气的火灾爆炸危险性。同时,还针对气田安全生产的实际情况提出了相应的对策措施。

China has started developing CO2 sour gas fields. While developing this kind of gas field,explosion characteristic of the fire accidents and asphyxiation accidents caused by natural gas should be attached with great importance. To identify the threshold concentration of CO2 and to figure out the corresponding protective measures are of great practical significance. This paper performed some researches into the explosion limits of natural gas which contains CO2. The obtained graphs present the explosion ranges of CH4,air and CO2. The results show that while air blend's CO2 content reaches 13.86%,and that of CH4 reaches 7.48%,then the lower explosion limit and the upper explosive limit of CH4 are the same. While air blend's CO2 content is higher than 13.86%,people should pay more attentions to asphyxiation accidents which might be caused by CO2. While CO2 content is lower than 13.86%,people should pay more attentions to fire and explosion risks. In addition,this paper puts forward some countermeasures in accordance with the safety production status at gas fields.