Treatment of NOx by Discharge Plasma

设计了三种不同类型的NOx处理反应器模型，并对其基本放电特性、臭氧生成和NOx去除进行了研究。所制备的反应器分别采用3种放电方式：1）水面电晕放电，2）两级电除尘器直流电晕放电，3）多极板阻挡放电，其中锯齿形电极在水面电晕放电中表现出较好的自由基生成特性和柴油机尾气NOx净化性能。设计了水面放电电除尘器作为同时除尘和脱硝的反应器。电除尘器利用电晕放电空间产生的离子、臭氧和OH自由基等离子体化学反应，使除尘和脱硝更好地进行。为了获得水面电晕放电的基本数据，用多功能测量仪测量了水面电晕放电的正负伏安特性和臭氧产生量 ...更多信息 i针和锯齿型放电电极。在不同的脉冲电压波形下，测量了脉冲电晕特性。实验在常压和室温下进行。直流电晕和脉冲电晕对水面的作用都表现出稳定的V-I特性，尽管电晕风会使水面产生波动。在直流和脉冲电晕中，正流光电晕比负流光电晕产生更多的臭氧。利用电除尘器模型对柴油机尾气进行了除尘和脱硝试验。研究结果表明，在脱硝除尘过程中，对水面的电晕放电为NO的氧化和NO_2的溶解提供了较好的条件。针对汽车隧道或地下停车场的污染空气净化问题，设计了一种电除尘器模型。利用该模型进行的粉尘和NOx处理试验结果表明，负荷电除尘效果较好，但NOx处理效果较差。设计了阻挡放电脱硝反应器，并进行了各种条件下的试验。结果表明，存在最大臭氧产生量的合适频率和NOx处理性能的最低放电功率。少

Three types of NOx treatment reactor model were designed and investigated on the basic discharge characteristics, ozone generation and NOx, removal. The prepared reactors were application of discharge : 1)Corona discharge over water surface, 2)DC corona in the two-stage ESP model, 3)Barrier discharge by multi plate electrodes.In corona discharge over water surface, the discharge electrodes of saw-edge type showed better characteristics on radical production and NOx treatment test with diesel engine exhaust gas. The ESP with the discharge electrode over water was designed as the reactor for removal of dust and NOx simultaneously. The ESP was expected to make the better proceeding of dust collection and the plasma chemical reactions for NOx removal by the ions, ozone and OH radical produced in the corona space. In order to get the fundamental data of the corona discharge over the water surface, positive and negative V-I characteristics and the ozone production were measured with the mult … More i needle and the saw-edge type of the discharge electrodes. The pulse corona characteristics were also measured with some different waveforms of the applied pulse voltage. The experiments were carried out under the atmospheric pressure and room temperature. Both DC and the pulse corona to the water surface showed the stable V-I characteristics though the surface of water was waved by the corona wind. The positive streamer corona showed the more ozone production than the negative one both in the DC and in the pulse corona. Some dust and NOx treatment tests by the model ESP reactor were carried out with diesel engine exhaust gas. The corona discharge to the water surface was confirmed to induce the better conditions for the proceeding of the NO oxidation and the NO_2 dissolution into water in the NOx removal processes as well as dust catching. An ESP model was designed for the contaminated air cleaning in the automobile tunnel or in the underground parking space. The results of dust and NOx treatment tests by the model showed good dust removal rates in negative charging but less removal rate for NOx treatment. Barrier discharge reactor for NOx treatment was also designed and tested under various conditions. They showed there was the fitting frequency for maximum ozone production and the lowest discharge power for NOx treatment performance. Less