三电极脉冲沿面流光放电等离子体防破风力发电机叶片覆冰的方法与机制

As a clean and renewable energy, wind power has got the great attention of Chinese government and Chinese people. An effective technique of anti-icing and de-icing for wind turbine blade is very important to improve the stabile operation of wind power. According to the requirement of anti-icing and de-icing for wind turbine blade, the principle of the fast excited by nanosecond pulse and the coupling effect of electric field produced by three-electrode system, a method of anti-icing and ice-breaking for wind turbine blade using three-electrode pulsed surface streamer discharge plasma is proposed to enhance the discharge intensity and discharge stability in a mixture of high humidity air, ice or ice-water and achieving the effectiveness of anti-icing and ice-breaking for blade. It is developed from typical surface discharge system and the second grounded electrode is arranged on the same side of the original high-voltage electrode. Coupled electric field can be generated when the three-electrode system is excited by nanosecond pulse, which can induce surface streamer discharge plasma and cause series of physical effects such as heating, pressure wave and force via reinforcing the chemical reaction among the particles. As a result, the application performance of anti-icing and ice-breaking for blade using plasma is improved. The generation method of three-electrode pulsed surface streamer discharge plasma, the effect and influencing factors of anti-icing and ice-breaking for wind turbine blade will be investigated. In the end of the research, we hope to reveal the mechanism of anti-icing and ice-breaking of wind turbine blade using pulsed surface streamer discharge plasma through exploring the formation process of plasma physical effects via plasma diagnostics and numerical simulation. This project is expected to provide reference for the development of novel technology for anti-icing and de-icing of wind turbine blade.

风电作为清洁可再生能源受到我国政府和人民的高度重视，而有效防除风力发电机叶片覆冰技术，对提高风电稳定运行水平是非常重要的。本申请面向有效防除风力发电机叶片覆冰需求，针对提高沿面放电等离子体强度和在高湿空气、冰相或冰水混合环境下放电稳定发生与有效防破叶片覆冰的问题，依托纳秒脉冲快速激励和三电极电场耦合作用的原理，提出三电极脉冲沿面流光放电等离子体防破风力发电机叶片覆冰的方法，是在传统两电极配置的沿面放电电极结构基础上，于高压电极同侧加装第二接地电极构成三电极模式，在三电极之间施加纳秒脉冲高压形成耦合电场诱导沿面流光放电等离子体产生，增强等离子体中粒子间化学反应产生热、波和力等物理效应的能力，高效防破叶片覆冰。研究三电极脉冲沿面流光放电等离子体发生方法、防破叶片覆冰效果及其影响因素，通过物理效应形成过程的诊断与数值模拟，揭示等离子体防破叶片覆冰机制。目的是为研发新的防除叶片覆冰技术提供参考。

风力发电机叶片覆冰对其正常工作带来严重问题。沿面介质阻挡放电（SDBD）作为一种新型的除冰技术，由于能耗低、响应快和良好的除冰性能近年来受到学者们的青睐。基于此，本项目采用脉冲SDBD对覆冰进行有效破除。研究工作和结果如下：.1. 搭建了实验系统，提出并验证了三电极脉冲沿面介质阻挡放电防破覆冰的有效性。.2. 研究了传统两电极脉冲沿面流光放电等离子体特性。得到单次正脉冲放电由正电流对应的一次流光和负电流对应的二次流光组成。数值模拟得到了正电流由电子电流组成，负电流由离子电流组成；且发现残余表面电荷越多，抑制一次流光长度和发光强度越明显，但有利于反向电场的增强，进而增强二次流光强度。.3. 研究了三电极脉冲沿面流光放电等离子体特性。结果是三电极脉冲沿面流光放电较两电极脉冲沿面流光放电有更强的沉积能量和更高的激励器表面温度；流光发展图像显示三电极脉冲沿面流光放电除了包含一次流光和二次流光外，在一次流光到达第二接地电极后，形成了过渡流光。数值模拟得到第二接地电极的存在可导走放电产生的电荷，减少介质表面电荷积累，有利于过渡流光阶段电场增强。.4. 三电极脉冲沿面火花放电等离子体特性研究。放电时空演图像得到三电极脉冲沿面火花放电由一次流光、过渡流光和火花放电组成；发射光谱得到火花放电最大电子温度约为4.815 eV，火花放电阶段电子密度约为4.30-7.06×1017 cm-3。纹影仪和高马赫数流体模型分析发现了脉冲沿面火花放电能量的快速释放，放电区域温度急剧上升至约4000 K产生冲击波。.5. 脉冲沿面介质阻挡放电除冰过程的等离子体特性研究。实验结果表明三电极脉冲沿面火花放电可有效破除表面明冰，破冰过程可分为三个放电阶段：电晕放电、流光放电和沿面火花放电；沿面火花放电的产生诱导强烈的冲击波破碎明冰。根据放电过程所测发射光谱谱线，计算得到电子密度约为2.08×1017 cm-3。