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《International Journal of Hydrogen Energy》2020,45(6):3769-3775
Practically, before being fed to the treatment plant, food waste (FW) is stored for up to a week in a storage tank under ambient temperature condition, which would have an impact on the bioenergy yield. In the present work, FW was stored at different temperatures (5 °C, 20 °C, and 35 °C) for 0 d, 1 d, and 2 d, and it was used as a feedstock for mesophilic H2 fermentation. H2 production curves were divided by three groups, finally attaining 1.7–1.8 mol H2/mol hexoseadded, 1.4–1.5 mol H2/mol hexoseadded, and 1.2 mol H2/mol hexoseadded, achieved from the (fresh, FW stored at 5 °C), (FW stored at 20 °C, and 35 °C for 1 d), and (FW stored at 35 °C for 2 d), respectively. The different performance was attributed to the growth of indigenous lactic acid bacteria such as Lactobacillus and Weissella during storage under high temperature condition. In addition, it was found that the activity of homoacetogenic reaction (R17, 4H2 + CO2 → Acetate) calculated by establishing metabolic flux balance was different depending on the H2 production performance. The flux of R17 ranged 0.03–0.06 under low H2 yield achieved conditions, while it increased to 0.10–0.17 those showing low H2 yields. 相似文献
44.
针对5G基站设备相对于以往2G/3G/4G设备的变化,面向一线勘察设计人员,阐述5G基站在供配电需求方面功耗增大、供电方式多样化、供配电改造工作量和难度加大等相应变化,归纳相应的勘察前期准备工作要点,分析在实际工作中可能面临的外市电引入改造、供电方式选择的多样性、新型锂电池应用等重点、难点,介绍理想的5G供配电模式及发展方向,最后提出5G基站供配电勘察设计工作思路调整的建议。 相似文献
45.
刘刚 《中国水能及电气化》2020,(4):30-32,52
水电站厂用电指标使用综合厂用率,反映电站厂用电消耗的实际情况,可通过厂用电率合理性分析电站厂用耗电情况以及节能降耗挖潜的空间,促进厂用电的合理管理,提高电站效益。文章结合华能甘肃水电开发有限公司管控的6座小型水电站厂用电管理实践,分析了影响水电厂用电损耗的相关因素,提出了厂用电节能降耗的应对措施。 相似文献
46.
An Improved Torque Sensorless Speed Control Method for Electric Assisted Bicycle With Consideration of Coordinate Conversion 下载免费PDF全文
Tinghua Li Qinghua Yang Xiaowei Tu Bin Ren 《IEEE/CAA Journal of Automatica Sinica》2020,7(6):1575-1584
In this paper, we propose an improved torque sensorless speed control method for electric assisted bicycle, this method considers the coordinate conversion. A low-pass filter is designed in disturbance observer to estimate and compensate the variable disturbance during cycling. A DC motor provides assisted power driving, the assistance method is based on the real-time wheel angular velocity and coordinate system transformation. The effect of observer is proved, and the proposed method guarantees stability under disturbances. It is also compared to the existing methods and their performances are illustrated through simulations. The proposed method improves the performance both in rapidity and stability. 相似文献
47.
针对机械振动无线传感器网络因拓扑不均衡导致传输时延和网络传输能耗增加的问题,提出了一种基于模糊层次分析(fuzzy analytic hierarchy process,简称FAHP)的均衡拓扑构建方法,该方法由构建模糊判断矩阵和计算权重向量组成。首先,传感器节点进行簇内通信获取信标广播信息,将信标节点网络决策因子统一量纲化,利用网络决策因子构建模糊判断矩阵;其次,检验模糊判断矩阵一致性,采用行和归一化处理或拉格朗日最小二乘法计算权重向量;最后,传感器节点通过权重向量计算出各个信标节点综合权值,关联最优信标节点为父节点加入网络,将提出的模糊层次分析拓扑构建方法与基于链路质量单准则构建网络拓扑机制进行对比。实验结果表明,该方法能有效改善传输时延和机械振动无线传感器节点网络寿命。 相似文献
48.
The consumption of fossil fuel has resulted in global warming, environmental pollution, and many other crucial problems. Replacing fossil fuel with renewable energy has become an important issue over the recent decades. As a renewable clean energy, wind power is a relatively well‐developed and promising energy method for current technology development in China. Under the background of growing demand for electricity and enhancing awareness for environmental, the “Internet+ wind power” concept has emerged based on both the wind power's characteristics that renewable and non‐polluting, and the rapid development of the Internet in China. Through querying an amount of literature and information, this paper reveals the resource endowment and policy environment about wind power and energy Internet at first. Then, the PEST‐SWOT strategy analysis model is used to analyze the internalities (strengths and weaknesses) and the externalities (opportunities and threats) of “Internet+ wind power”. According to these results, the paper puts forward some measures (development and utilization, business mode) for wind power accommodation. Then some policy recommendations have been proposed. The government should provide favorable conditions for wind power grid with the “Internet+” technology innovation. 相似文献
49.
Jian-hua XIANG Chao ZHOU Chun-liang ZHANG Gui-yun LIU Cong-gui CHEN Wei ZHOU 《中国有色金属学会会刊》2018,28(7):1404-1412
A theoretical model of phase change heat sink was established in terms of thermal resistance network. The influence of different parameters on the thermal resistance was analyzed and the crucial impact factors were determined. Subsequently, the forming methods including ploughing–extrusion and stamping method of boiling enhancement structure at evaporation surface were investigated, upon which three-dimensional microgroove structure was fabricated to improve the efficiency of evaporation. Moreover, the crucial parameters related to the fabrication of miniaturized phase change heat sink were optimized. The heat transfer performance of the heat sink was tested. Results show that the developed phase change heat sink has excellent heat transfer performance and is suitable for high power LED applications. 相似文献
50.
An up to date review of continuously variable speed wind turbines with mechatronic variable transmissions 下载免费PDF全文
Xiuxing Yin 《国际能源研究杂志》2018,42(4):1442-1454
As a promising and potential alternative to conventional fixed or variable speed wind turbines, continuously variable speed wind turbines (CVSWTs) with variable transmissions offer improved power efficiency and enhanced power control capabilities. The CVSWTs can be generally achieved by adapting mechatronic variable transmissions in the turbine drive train for continuously variable speed operations for wind turbines. Therefore, this paper serves to provide an up to date and exhaustive review of the CVSWTs with mechatronic variable transmissions such as mechanical variable transmission, electrical variable transmission, and power splitting transmission. In this paper, the analysis of CVSWTs with different mechatronic transmission topologies is performed regarding basic configurations, dynamic characteristics, control principles, and experimental or simulation results. Review results indicate the feasibility of applying CVSWTs with such mechatronic transmissions and highlight superiorities of the CVSWTs with power splitting transmission. The CVSWT with power splitting transmission will be particularly suitable for megawatt‐scale turbine systems and will hence increase the economic competitiveness of these turbines due to its large power capacity and high reliability. The directions or challenges for future investigations of CVSWTs with such mechatronic transmissions are also presented to foster in‐depth understanding of such CVSWTs and their control strategies. 相似文献