初始温度对城镇燃气爆炸强度的影响研究

Influences of the initial temperature on theexplosion intensity of coal gas

为了探讨城镇燃气爆炸强度与反应初始温度的对应关系,根据工程热力学研究定组分混合气体的基本方法以及阿马格分体积定律将城镇燃气简化为含碳、氢、氧、氮的单一气体,简化其热化学反应方程式及反应终态温度的求解办法。在此基础上采用经典的气体爆炸强度公式计算不同反应初始温度下城镇燃气(体积分数10%)-空气混合气体理论上的最大爆炸压力和最大压力上升速率。结果表明,城镇燃气的最大爆炸压力及最大压力上升速率随初始温度的提高而线性减小,近似成反比例关系。为了验证理论计算所得结论的正确性,采用经典爆炸特性参数测试系统实测了该混合气体对应初始温度下的爆炸强度。实测结果与理论计算结果所得结论基本吻合,且最大爆炸压力的理论值与实测值最大误差为13.95%,最大爆炸压力上升速率的理论值与实测值最大误差为14.52%,满足工程应用(最大误差不超过20%)的需要。该理论计算方法可以近似估算不同初始温度下城镇燃气-空气混合气体的爆炸强度。在爆炸极限范围内城镇燃气的爆炸强度随反应初始温度的增加而线性减少,二者近似成反比例关系。

The present paper is aimed to study the corresponding re- lationship between the explosion intensity of coal gas and the initial temperature of different reactions. According to engineering thermo- dynamic research, the basic method on determining composition of mixed gas is applied to coal gas. The coal gas is simplified as unitary gas. Its thermochemical reaction equation is simplified. On the basis of the simplified calculation, we have worked out the maximum ex- plosion pressure on the condition of the initial temperatures of differ- ent reactions. At the same time, we have also deduced the maximum rate of pressure rise, which can be measured by means of explosion characteristic parameters. In addition, we have compared and ana- lyzed the practical value and the theoretical calculation results of the maximum explosion pressure and the maximum rate of pressure rise. As can be seen from the measured waveform through experiments, the maximum explosion pressure tends to decrease linearly with the rising of the initial temperature. The maximum error between the theoretical value and the experimental value of the explosion pressure turns to be 13.95%. At this, it was found that the maximum rate of explosion pressure rise is likely to be dropping linearly with the increment of the initial temperature. We can also find here that the maximum error be- tween the theoretical value and the experimental value of the maxi- mum rate of pressure rise is equal to 14.52%. Thus, it can be in- ferred that the theoretical value comes into conformity with the experi- mental value, and meet with the need of coal gas explosion engineer- ing. The results have thus proven that the explosion intensity of the coal gas agrees perfectly with the data measured in the experiments. Therefore, our conclusion can be said to provide an efficient theoreti- cal foundation for estimating the explosion intensity of poly-ingredient determining composite flammable mixed gases.