温度压力耦合对甲烷爆炸极限影响的试验研究

Experimental study on the explosion limits of methane under coupling effects of temperature and pressure

在对甲烷爆炸极限理论分析的基础上,建立了一套温度压力耦合条件下的气体爆炸极限测试系统,并对甲烷在50~200℃和0.2~1.0 MPa环境条件下的爆炸极限进行了试验研究。结果表明：随环境温度升高和环境压力增大,甲烷爆炸上限升高,爆炸下限下降,爆炸范围变大;在200℃和1.0 MPa条件下,试验测得的甲烷爆炸下限为4.05%,爆炸上限为25.6%,相对于常温常压条件爆炸下限下降了0.95%,而爆炸上限上升了9.6%,这表明初始温度和压力对甲烷爆炸上限的影响较大,而对爆炸下限的影响较小。

In hoping to prevent methane explosion accidents in differ ent conditions of temperature and pressure, the paper intends to establish a test system for testing the gas explosion limits under coupling effects of temperature and pressure. So far as we know, we have set the explosion limits of methane under the environmental conditions of 50 -200 ℃ and 0.2 -1.0 MPa through experiments based on the theoretical analysis of methane explosion limits. The experimental re suits we have gained indicate that： with the rising of temperature （50 200 ℃ ） and pressure （0.2 - 1.0 MPa）, the methane upper explo sion limit increases, the lower explosion limit declines, and the ex plosion range is likely to widen. When the environmental temperature comes to 200 ℃ with the environmental pressure reaching 1.0 MPa, the methane would come to its lower explosion limit of 4.05% ac cording to the results of our experiments. However, when the envi ronmental temperature comes to 25 ℃, and the atmospheric pressure to 0.1 MPa, the methane tends to come to its lower explosion limit of 5.0% according to the theoretical study results, so under such tem poral and spatial condition, the lower explosion limit of methane may decline to 0.95 % . Nevertheless, when the environmental tempera ture reaches 200 ℃ and the environmental pressure goes up to 1.0 MPa, the methane would go up to its upper explosion limit, that is, 25.6 % according to the results of our experiments. But, when the environmental temperature is 25 ℃ , and the environmental pressure is 0.1 MPa, the upper explosion limit of methane will be 16.0% in theory. Under this condition of time, the upper explosion limit of methane tends to rise to 9.6 %. Thus, it can be followed that the up per explosion limit of methane can be greatly influenced by the envi ronmental temperature and pressure, while its lower explosion limit would be less affected by the environmental temperature and pres sure. Thus, comparing the theoretical results with the experimental results of methane explosion limits, it can be concluded that they are in perfect agreement with each other, which suggests that our experi mental study results prove to be reasonable and perceivable. The ex perimental results and changing regularities can surely serve as a the oretic basis for preventing mining gas explosive accidents in a down to earth way.