本质安全Ⅰ类电容电路最小点燃电压曲线分析

Analysis of Minimum Ignition Voltage Curve of Intrinsically Safe ClassⅠ Capacitor Circuit

本文通过对本质安全Ⅰ类电容电路的最小点燃电压曲线的研究,准确实现了最小点燃曲线的数值化.比较最小点燃曲线上各点的电容储能与最小点燃能量,发现在电容小于10μF时,电容储存能量基本等于最小点燃能量的6倍;而当电容大于10μF时,电容储能随着电容的增大而增大,以至于电容储能远大于最小点燃能量.该发现将最小点燃曲线与最小点燃能量联系起来,可弥补能量法评价本安电路的不足.通过研究不同限流电阻下的最小点燃曲线,总结出最低点燃电压与限流电阻和电路等效电容的关系,可实现任意限流电阻下的电容电路本安性能评价,使得基于最小点燃曲线的非爆炸性评价具有现实意义.

This paper makes the study of the minimum ignition voltage curve of intrinsically safe class Ⅰ capacitor circuits,and the accuracy of the minimization of the ignition curve is implemented.Comparing the capacitance storage at each point on the minimum ignition curve with the minimum ignition energy,we found that the capacitance storage energy is equal to 6 times of the minimum ignition energy when the capacitance is less than 10μF,and when the capacitance is greater than 10μF,the capacitance storage capacity increases as the capacitance increases,as a result the capacitance energy storage is much larger than the minimum ignition energy.This finding encourages us to link the minimum igniting curve to the minimum igniting energy so as to make up the shortage of energy evaluation method of intrinsically safe circuit.The study of the minimum ignition curve under different current limiting resistors enables us to summarize the relationship between the minimum ignition voltage and the current limiting resistor and the equivalent capacitance of the circuit,and the intrinsic safety performance of the capacitor circuit under any current limiting resistor can be realized.The non-explosive evaluation based on the minimum ignition curve is more practical.