近大气压DBD微放电模式与氧等离子体反应效能研究

发布时间：2018-06-15 13:32

本文选题：气压 + 放电模式　；参考：《大连海事大学》2017年硕士论文

【摘要】：利用高频激励强电场放电的高级氧化技术能够快速有效地处理船舶压载水和饮用水,该技术中氧等离子体反应器模块是核心组件,氧等离子体反应效能直接影响水处理效果。实际工作中,当反应器模块的进气量与气液混溶射流器的运行速度不匹配时,反应器模块的运行气压低于或高于大气压,变动范围在60-150 kPa之间,影响氧活性粒子反应效能,最终影响水处理效果。本文利用自行设计的氧等离子体反应器,分别在60-100 kPa和100-150 kPa气压条件下,研究了气压对氧活性粒子反应效能的影响,并借助针-板放电装置探究了气压对单微放电的放电状态和放电模式的影响。结果显示,单微放电在激励电压正负半周期内表现出不同的放电模式,激励电压正半周期放电模式为微流注放电,负半周期放电模式为微类辉光放电。运行气压与激励功率改变使得反应器模块中放电气隙折合场强度变化,导致在施加不同功率时,模块表现出不同的放电特性与等离子体化学反应效能。放电气隙折合电场强度是影响氧活性粒子反应效能的主要因素,当氧等离子体反应器内气压降低时,放电气隙折合电场强度增强,O_2电离度增大,气体放电尺度增大,放电强度增强,放电气隙击穿电压降低,单位时间放电电流脉冲数量增多,放电电流脉冲幅值减小,首个放电电流脉冲出现时间提前,放电气隙等效电阻减小,电介质层等效电容增大。可以通过调节气压和激励功率控制折合电场强度。在媒质气体为O_2的条件下,氧等离子体反应器模块存在最优折合电场强度,低于该折合电场强度,氧活性粒子反应效能随折合电场强度增强而增加,高于该电场强度,则会受等离子体化学反应过程中产生的反应热等因素的影响,氧活性粒子反应效能随折合电场强度增强而反而降低。在实际应用中,为使氧活性粒子反应效能最大,需根据氧活性粒子反应器内气压条件调节激励功率,当反应器在常压运行时激励功率要控制在250-300 W,气压降低到60 kPa时激励功率要控制在150 W,而当气压升高到150 kPa时激励功率要控制在400 W,使氧等离子体反应器模块处于最佳工作状态,从而更好地为相关水处理技术服务。
[Abstract]:The advanced oxidation technology with high frequency excited strong electric field discharge can deal with ship ballast water and drinking water quickly and effectively. The oxygen plasma reactor module is the core component in this technology, and the efficiency of oxygen plasma reaction directly affects the water treatment effect. In practice, when the air intake of the reactor module does not match the speed of the gas-liquid mixed jet reactor, the operating pressure of the reactor module is lower or higher than the atmospheric pressure, and the range of variation is 60-150 KPA, which affects the reaction efficiency of the oxygen active particles. Finally, the effect of water treatment is affected. In this paper, the effect of air pressure on the reaction efficiency of oxygen active particles was studied under the pressure of 60-100 KPA and 100-150 KPA, respectively, using a self-designed oxygen plasma reactor. The effect of air pressure on the discharge state and discharge mode of single micro discharge was investigated by means of a needle-plate discharge device. The results show that there are different discharge modes in the positive and negative half period of the excitation voltage. The positive half period discharge mode of the excitation voltage is a micro current discharge mode, and the negative half period discharge mode is a micro glow discharge mode. The change of operating pressure and exciting power makes the discharge air gap change in the reactor module, resulting in different discharge characteristics and chemical reaction efficiency of plasma when different power is applied. The electric field intensity of the discharge gap is the main factor affecting the reaction efficiency of the oxygen active particles. When the pressure in the oxygen plasma reactor decreases, the discharge air gap electric field intensity increases, the ionization degree of the gas discharge increases and the discharge scale of the gas increases. With the increase of discharge intensity, the breakdown voltage of discharge gap decreases, the number of discharge current pulses increases, the amplitude of discharge current pulse decreases, the first discharge current pulse appears earlier, and the equivalent resistance of discharge air gap decreases. The equivalent capacitance of dielectric layer increases. The reduced electric field intensity can be controlled by regulating air pressure and exciting power. Under the condition that the medium gas is O _ 2, the oxygen plasma reactor module has an optimal reduced electric field intensity, which is lower than that of the oxygen plasma reactor module, and the reaction efficiency of the oxygen active particle increases with the increase of the reduced electric field strength, which is higher than that of the electric field. The reaction efficiency of oxygen active particles decreases with the increase of electric field strength. In practical application, in order to maximize the reaction efficiency of oxygen active particles, it is necessary to adjust the excitation power according to the pressure conditions in the oxygen active particle reactor. When the reactor operates at atmospheric pressure, the excitation power should be controlled at 250-300 W, when the pressure is reduced to 60 KPA, the excitation power should be controlled at 150 W, and when the pressure rises to 150 KPA, the excitation power should be controlled at 400 W, so that the oxygen plasma reactor module will be controlled. In the best working condition, In order to better serve the related water treatment technology.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O461

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