Experimental Research On Spark Discharge Energy Measurement

With the application of new technologies and expansion of production scale, the dust explosions of growing frequency caused serious casualties and property damage. The depth study of dust explosion parameters is therefore very necessary-it has important practical significance and scientific value in the prevention and control of such industrial devastating accidents.The main purpose of this paper is to use integral measurements the minimum ignition energy of dust clouds and dust explosion in the spark ignition energy of experimental apparatus. Currently, the minimum ignition energy of dust cloud the main reference test VDI2263 Association of German Engineers and the International Electrotechnical Commission IEC31 standard. In this paper, based on previous studies, using the combination of theoretical analysis and experimental research methods, adopting oscillography, to utilize high voltage probe and current probe measure the voltage and the current across the electrode, a lot of data were processed and analyzed and then integrate the discharge power to get the discharge energy.Due to constraints of transport, purchase and other matters, the use of chemical igniters for large energy tests are restricted, so it becomes an urgent need to study about electrostatic ignition, which by now results discrepant explosion factors to the chemical one. The two ignition methods differ not only in mechanism, but also in the energy of sparks. For the first time, the energy of spark in the electrostatic discharge was measured, and from the discharge curve, the value of current, gap resistance, discharge power and energy were compared and analyzed. The high energy sparks data was adapted; the waveform analysis and the calculation of its integrating energy were made; Multisimll simulation of the charge and discharge was used and the simulation data was analyzed. According to the equivalent analysis of R-C-L second-order zero-input circuit, the ratio of the integrating energy to the charging energy was theoretically analyzed. R-C-L discharge equation is established based on equivalent circuit of ignition system under inductive load, gap resistance and gap current changes during the process of electric spark discharge are modeled using Runge-Kutta method, discharge energy(spark energy) in electrode gap is calculated through discharge model. The calculating results of discharge model combined with the experimental results provides effective guidance for the experimental determination of parameters in ignition circuit, and provides important experimental results for the use of spark energy to measure minimum ignition energy of dust cloud. In the case of large energy, using current rise time and other parameters to calculate the equivalent resistance of circuit, discharge energy ratio was analyzed. In addition, the experience parameters, which are maximum explosion pressure (Pmax), explosion index (Kst) and the lower explosion limit (MEC), of lycopodium and HCMA with chemical and electrostatic ignition modes, were compared and analyzed. The difference between the reasons and results of two kinds of ignition was discussed.