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利用等离子体技术可以裂解甲烷,产生C2烃和氢气等具有更高价值的物质。对等离子体放电参数优化以提高甲烷等离子体转化效率具有重要意义。文中基于同轴DBD反应装置,在自主研制的微秒和纳秒脉冲电源的激励下,改变电源参数和气体流速,研究了甲烷裂解过程中不同参数下初始击穿电压的变化规律、放电图像、Lissajous图形以及单脉冲内的能量和功率,为甲烷转化提供参考。实验结果表明,两台电源作用下气体初始击穿电压均随脉冲重复频率的增加而下降,但纳秒源作用时该趋势更明显;放电强度均随脉冲重复频率增加而加强,相同参数下,微秒源作用时放电更强;施加电压一定时,不同脉冲重复频率以及不同气体流速下Lissajous图形形状几乎一致,微秒源作用时的图形更接近典型的平行四边形;气体流速和脉冲重复频率相同时,两台电源单脉冲内放电能量与所加电压几乎成直线关系变化,气体流速和施加电压相同时,单脉冲内放电能量几乎不受脉冲重复频率的影响,但是纳秒源可以得到更高的瞬时功率。实验表明,脉冲电源可以作用于DBD反应器用于转化甲烷,纳秒源作用时系统的效率比微秒源更高。
Using plasma technology, methane can be cracked to produce higher value materials such as C2 hydrocarbons and hydrogen. It is significant to optimize plasma discharge parameters to improve methane plasma conversion efficiency. In this paper, based on the coaxial DBD reaction device, under the excitation of self-developed microsecond and nanosecond pulse power supply, the parameters of the power supply and the gas flow rate are changed. The variation law of the initial breakdown voltage under different parameters in methane cracking process is studied. Lissajous pattern and the energy and power in a single pulse provide a reference for methane conversion. The experimental results show that the initial breakdown voltage of gas decreases with the increase of pulse repetition frequency under the two power supplies, but the trend is more obvious when the nanosecond source is applied. The discharge intensity is strengthened with the increase of pulse repetition frequency. Under the same parameters, When the applied voltage is constant, the shapes of Lissajous patterns at different pulse repetition frequencies and gas velocities are almost the same, and the patterns at microsecond source are closer to the typical parallelograms. The gas flow rate and pulse repetition frequency At the same time, the discharge energy of one power pulse is nearly linear with the applied voltage. When the gas flow rate and applied voltage are the same, the discharge energy in one pulse is hardly affected by pulse repetition frequency, but the nanosecond source can get higher Instantaneous power. Experiments show that the pulse power can act on the DBD reactor for methane conversion, and the efficiency of the system is higher than the microsecond source when the nanosecond source is used.