Thermoelectric coupling analysis of high-voltage breakdown industrial frequency pyrolysis in Fuyu oil shale

Abstract A high voltage can achieve the electrical breakdown of an oil shale, and a heating channel is formed inside the oil shale. Subsequently, the industrial electrical frequency is used to heat the oil shale with the produced plasma and the inner surface of the conductive carbonization channel, which then causes the oil shale to crack. A three-dimensional coupling model of an oil shale is established by the finite element analysis software, and the temperature field distribution of a high-voltage breakdown of an oil shale is obtained by numerical calculations. The reliability of the numerical simulation is verified by laboratory tests. When the voltage is 1000 V, the breakdown current in the oil shale is 22 A. After heating for 6 min, the heating channel temperature of the oil shale reaches 643 °C. Within a 25-mm heating channel length, the temperature reaches 347 °C, which meets the demand of oil shale pyrolysis. Combined with the numerical simulations and experimental results, the high-voltage industrial-frequency pyrolysis oil shale has high heating efficiency and high energy utilization efficiency. Thermoelectric coupling analysis is an effective way to study the high-voltage-breakdown industrial-frequency pyrolysis of oil shale.