Experimental investigation on upstream and downstream discharges in airflows

Dielectric barrier discharge has widely used in airflow control, ignition and combustion, and other applications; the influence of airflow on dielectric barrier discharge is of extensive concern. Previous studies demonstrate that the discharge becomes more uniform and the discharge intensity decreases with increasing of airflow velocity. In this study, we adopt a discharge cell construction with upstream and downstream structure and study the discharge states and intensities. The experimental results demonstrate that within a specific range of airflow speed, the upstream discharge intensity is decreased, and the downstream discharge intensity is enhanced. The physical basis for this phenomenon is proposed as follows: Within a pulse interval time, some particles, such as charged and metastable particles produced by the upstream discharge, could be transported to the downstream region. The concentration of particles in the downstream region is increased, and these particles play a pre-ionization role in the downstream discharge, the intensity of the downstream discharge is enhanced. Further, factors such as the pulse frequency and the distance between electrodes are discussed in detail, along with the conditions for enhancing downstream discharge intensity.     

关于汽轮机蒸汽功率测量的多传感器信息融合方法的研究

在功频调节系统中，利用电功率信号作为反馈信号会引起反调现象的产生。利用汽轮机中特殊位置处的蒸汽压力对蒸汽功率的变化响应快和电功率信号的稳态精度高的特性，将两者组成一个信息融合对，通过构造互补FRF(频率响应函数)对，在频域内进行信息融合，获取高性能的蒸汽功率信号。最后采用仿真试验表明，通过此法获取的蒸汽功率信号作为功频调节中的功率反馈信号可明显减小反调现象。     

我国煤层气发电技术现状研究

随着能源危机加剧,环境保护要求的提高,煤层气作为一种很好的清洁能源,越来越受到人们的重视.本文通过对国内煤层气的利用现状研究,阐述了煤层气发电的工艺流程及其不同的能量利用形式,比较了其优缺点.探讨了煤层气发电存在的问题以及关键技术,提出了一种新的循环形式.     

分体燃气轮机的总体方案研究

本文针对地面分布式能源系统应用,针对经典共轴燃气轮机由于压气机和透平共轴导致的机组的运行灵活性差的缺点,提出了一种分体式燃气轮机的概念,并分析分体式燃气轮机的集成原则和集成方案,同时研究了机组的参数耦合关系,并通过与经典燃气轮机的比较,对本文所提出的分体式燃气轮机的概念的特点和应用领域进行了讨论.结果表明这样分体式燃气轮机有多种组合方式,为适应分布式能源系统的灵活性要求提供了可能.     

Hysteresis characteristics of the initiating and extinguishing boundaries in a nanosecond pulsed DBD

The dielectric barrier discharge (DBD) is presently used in many fields, including plasma medicine, surface modification, and ozone synthesis; the influence of airflow on the DBD is a widely investigated topic. In this work, a hysteresis characteristic on the initiating and extinguishing boundaries is observed in a nanosecond pulsed DBD, which is sensitive to the variation in the airflow velocities and pulse repetition frequencies (PRFs). It is found that, at a certain airflow velocity, the initiating PRF is higher than the extinguishing PRF. This difference between the initiating PRF and the extinguishing PRF leads to a hysteresis phenomenon on the initiating and extinguishing boundaries. When the airflow velocity is increased, both the initiating and extinguishing PRFs are increased and the difference between the initiating PRF and the extinguishing PRF also increased. The hysteresis width between the initiating and extinguishing boundaries is enhanced. To explain these results, the physical processes involved with the seed particles and the mechanisms of forming discharge channels are discussed.     

分体式燃气轮机的变工况性能分析

采用商业软件Thermoflex对分体式燃气轮机进行模拟,建立了系统的性能分析模型,分析指出压气机转速、透平转速和燃气初温是影响系统变工况性能的主要因素,并对转速和燃气初温变化时系统的输出性能进行了计算分析.通过和共轴燃机的比较分析,得出了分体式燃气轮机的性能潜力.