Overall Evaluation of Plasma Exhaust Gas Cleaning Method for Diesel Engine Generator

柴油发电机等离子废气净化方法的总体评价

基本信息

批准号：
17560270
负责人：
YOSHIOKA Yoshio
金额：
$ 2.18万
依托单位：
KANAZAWA INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560270/
关键词：
Barrier discharge NOx removal Diesel engine Exhaust gas recirculation (EGR)Urea Automatic control Catalysis Discharge mode バリヤ放電発電設

项目摘要

Based on the original scheme of research, various NOx removal experiments were carried out, and analyzed the results. The followings are the principal conclusion of this work.(1)Barrier discharge usually has a filamentary micro-discharge mode. As the radical formation by high energy electrons occur only in the thin micro-discharge channels, we considered that to make such micro-discharge as small as possible and to increase the number of micro-discharges would be better for NO removal performance. We found that by increasing the temperature of barrier materials or by using acrylic barrier, the barrier discharge mode changed from filamentary mode to glow like mode. The glow like discharge mode was confirmed to increase the NO removal efficiency by 170%.(2)The reason why the temperature of barrier material changes the discharge mode was investigated using very simple needle to plane discharge device. We found that the surface discharge changes with temperature and at the top of surface d … More ischarge, some glow like discharge mode appears. This phenomenon is considered to be a cause of the change of discharge mode.(3)As a new method, we made an experimental system, with which we can test the effect of a combination of discharge, catalysis and ammonia. Ammonia is generated from urea resolved in water by heating it over 160℃. Various experiments were carried out, and we had a conclusion that a combination of ammonia, discharge and catalysis directly can reduce NOx from exhaust gas at relatively lower temperature such as 200℃, although the catalysis used work at the temperature more than 400℃ without discharge. Even if we added ammonia in exhaust gas and plasma treatment was done, the NOx removal performance is not improved.(4)The exhaust gas recirculation (EGR) reduces the emission of NOx from engine considerably. Therefore, if we apply EGR before the plasma treatment, the load of the plasma process will be lightened. It was demonstrated that EGR of 10% could decrease the energy for plasma process to 1/4 of the case without EGR application. The automatic control of NOx removal apparatus using EGR was developed. By controlling the discharge power of discharge device and EGR rate, we can keep the outlet NO concentration to a low constant level.(5)As for over all evaluation of the plasma process, we concluded that a combination of EGR and ozone injection would be the best. It can reduce the plasma energy to minimum, and meets the industrial demand of energy consumption. It can achieve much lower NOx level control than conventional ways. A combination of ammonia generated from urea, discharge and SCR has a merit that the water scrubber is not necessary. Plasma can lower the operating temperature of SCR considerably. However, the higher temperature operation of discharge device is not so stable, and there need another cost for urea for ammonia source. Less

根据最初的研究方案，进行了各种NOX去除实验，并分析了结果。以下是这项工作的主要结论。（1）屏障排放通常具有丝状微型放电模式。由于高能电子的自由基形成仅出现在薄的微型放电通道中，因此我们认为，要使这样的微型放电尽可能小，并增加微型电荷的数量，而无需删除性能就会更好。我们发现，通过升高屏障材料的温度或使用丙烯酸屏障的温度，屏障放电模式从丝状模式转变为“辉光模式”。确认闪闪发光的排放模式将无去除效率提高了170％。（2）屏障材料的温度更改的原因是使用非常简单的针对平面排放装置研究了放电模式。我们发现，表面排放随温度和表面d的顶部变化……更多的汇总，出现了一些闪闪发光，例如排放模式。这种现象被认为是出院模式变化的原因。（3）作为一种新方法，我们制造了一个实验系统，我们可以通过它来测试排放，催化和氨组合的效果。氨是由尿素中的尿素通过在水中加热160℃的加热而产生的。进行了各种实验，我们得出的结论是，氨，排放和催化剂的结合可以直接在相对较低的温度（例如200°）下从排气中降低NOX，尽管该催化剂在温度下使用的工作超过400°，而无需放电。即使我们在废气和血浆处理中添加了氨，也无法提高NOX去除性能。（4）废气再循环（EGR）仔细地减少了NOX的发射。因此，如果我们在血浆处理前应用EGR，则血浆过程的负载将减轻。事实证明，如果没有EGR应用，则10％的EGR可以将等离子体过程的能量降低到该病例的1/4。开发了使用EGR对NOX去除设备的自动控制。通过控制排放装置的放电能力和EGR速率，我们可以将出口不集中到低恒定水平。（5）对于对等离子体过程的所有评估，我们得出结论，EGR和臭氧注入的组合将是最好的。它可以将等离子能量降至最低，并满足能源消耗的工业需求。与常规方式相比，它可以实现低得多的NOX水平控制。由尿素，排放和SCR产生的氨组合具有不需要水洗涤器的优点。等离子体可以大大降低SCR的工作温度。但是，排放装置的较高温度运行并不那么稳定，氨源还需要尿素的另一个成本。较少的