A large-scale experimental study on CO2 capture utilizing slurry-based ab-adsorption approach

The increasing concentration of CO_2 in atmosphere is deemed the main reason of global warming.Therefore,efficiently capturing CO_2 from various sources with energy conservation is of great significance.Herein,a series of experiments were carried out to successfully test the slurry-based ab-adsorption method for continuously capturing CO_2 in the large-scale cycled separation unit with cost-effect taking into account the scale-up criteria.A bubble column(with height 4900 mm and inner diameter 376 mm) and a desorption tank(with volume 310 L) are the essential components of the separation unit.The novel slurry used in this study was formed with zeolitic imidazolate framework-8 and 2-methylimidazole-water solution.The influence of operation conditions was investigated systematically.The results show that increasing sorption pressure and slurry height level,decreasing gas volume flow and sorption temperature are beneficial for separation processes.The volume fraction of CO_2 in the feed gas was also studied.Although the scale-up effect had been observed and it was found that it exerted a negative effect on CO_2 capture,depending on experimental conditions,CO_2 removal efficiency could still reach 85%-95% and the maximum CO_2 loading in the recycled slurry could be up to0.007 mol·L~(-1)·kPa~(-1).Furthermore,the slurry-based method could be operated well even under very moderate regeneration conditions(333 K and 0.05 MPa),which means that the novel approach shows greater energy conservation than traditional amine absorption methods.     

3D Prussian blue/Pt decorated carbon nanofibers based screen-printed microchips for the ultrasensitive hydroquinone biosensing

Nowadays,water pollution has become more serious,greatly affecting human life and healthy.Electrochemical biosensor,a novel and rapid detection technique,plays an important role in the real-time and trace detection of water pollutants.However,the stability and sensitivity of electrochemical biosensors remain a great challenge for practical detections in real samples to the strong interferences derived from complex components and coagulation effects.In this work,we reported a novel three-dimensional architecture of Prussian blue nanoparticles (PBNPs)/ Pt nanoparticles (PtNPs) composite film,using 3D interweaved carbon nanofibers as a supporting matrix,for the construction of screen-printed microchips-based biosensor.PtNPs with diameters of～2.5 nm was highly dispersed on the carbon nanofibers (CNFs) to build a 3D skeleton nanostructure through a solvothermal reduction.Subsequently,uniform PBNPs were in-situ self-assembled on this skeleton to construct a 3D architecture of PB/Pt-CNF composite film.Due to the synergistic effects derived from this special feature,the as-prepared hydro-quinone (HQ) biosensor chips can synchronously promote both surface area and conductivity to greatly enhance the electrocatalysis from enzymatic reaction.This biosensor has exhibited a high sensitivity of 220.28 μA·L·mmol-1·cm-2 with an ultrawide linear range from 2.5μmol·L-1 to 1.45 mmol·L-1 at a low potential of 0.15 V,as well as the satisfactory reproducibility and usage stability.Besides,its accuracy was also verified in the assays of real water samples.It is highly expected that the 3D PB/Pt-CNF based screen-printed microchips will have wide applications in dynamic monitoring and early warning of ana-lytes in the various practical fields.     

不同形式电压下高压直流电缆试验终端电场与空间电荷分布计算

试验终端是高压直流电缆电气性能试验的重要组成部分,该文基于交流电缆水终端建立了直流电缆水油终端模型,并得到了直流电场下的电场和电荷分布.为研究不同形式电压下高压直流水油终端中电场强度及其电荷密度分布,首先建立了水油终端电场-空间电荷仿真模型,该模型考虑了空间电荷的注入以及空间电荷和电场的相互作用;接着将仿真结果与试验进行对比,以验证模型的正确性;随后,基于该仿真模型分析了直流电压及6种不同形式冲击电压下水油终端的电场强度、电荷密度分布规律,并与GB/T 31489.1规定的6种冲击电压下水油界面处的场强与电荷密度进行比较.结果 表明,雷电冲击电压在水油界面上产生的场强幅值最大,超过了水的击穿场强.因此水油终端不适用于雷电冲击试验.论文研究可为高压直流试验终端的研发提供参考.     

一种基于图计算的电力系统故障建模方法

故障建模是电力系统仿真分析的重要基础,如何快速准确对某类（N-1、N-2等）故障进行建模一直困扰电网分析人员。首先,分析了电力系统故障建模需要考虑的故障发展路径、故障动作时序两个要素,其中故障发展路径的搜索是故障建模的难点;其次,结合电力系统数据结构特征,提出了基于图计算的电力系统故障建模方法;最后,通过一个规模较大的省级电网验证了所提方法的有效性。在未来“双碳”“双高”电力系统发展的背景下,所提方法为电力系统在线、离线仿真分析所依赖的全网故障建模提供了新的思路和工具。     

基于自适应惯量阻尼的双馈风电机组虚拟同步控制策略

针对恒参数虚拟同步控制的双馈风电机组因有功功率突变而导致电网频率和输出功率振荡的问题,提出一种以虚拟电流为闭环参考输入量的虚拟同步控制的双馈风电机组控制策略.通过虚拟同步二阶小信号闭环传递函数,分析转动惯量和阻尼系数对系统稳定性的影响.结合频域指标关系,制定系统参数的选取规则.考虑双馈风电机组输出有功功率的变化阈值,提出一种适用于双馈风电机组的交错自适应虚拟同步控制策略,并根据特征根的根轨迹图分析不同参数下系统稳定情况.理论分析和仿真对比验证了所提出的控制策略和交错自适应算法的有效性.     

适用于非理想条件下的自适应自抗扰锁相环技术

为解决传统三相同步锁相环在电网电压波动时无法精确锁相的问题,本文通过引入二阶线性自抗扰控制技术代替传统PI控制,并利用其扩张状态观测器对各状态变量进行估计和补偿实现锁相.基于二阶广义积分器的移相特性提出一种快速计算正序电压幅值的算法,并以此为基础设计一种可以根据电压跌落深度自适应调节参数的自抗扰锁相环结构.仿真和实验表明,所提出的锁相环结构可以有效提高锁相环的动态性能,且能在非理想的工况下为逆变器并网发电提供可靠的基准信号.     

影响增强聚丙烯雾化测试结果的因素

雾化重量法是衡量汽车内饰材料挥发物中的有害成分对人体健康的影响程度的测试。因此,为了合理控制挥发性物质的产生,降低车内环境污染,对用于汽车内饰的材料进行雾化测试是十分必要的。通过控制变量研究样品状态、加工工艺、测试温度、测试时间、平衡时间对雾化重量法进行测试,分别测试了内饰材料增强聚丙烯系列的长玻璃纤维增强材料和短玻璃纤维增强材料散发量。得出同种材料测试温度是重量法雾化的主要影响因素,不同加工工艺材料的雾化结果不同,且不具备可比性,测试时间、样品状态和平衡时间对结果也有一定程度的影响,所以对改善材料的散发性和筛选材料时要明确样品和测试条件。     

塑料增韧增强技术现状分析及发展趋势

主要介绍了塑料增韧增强的技术研究现状,并例举了相关增韧增强材料的功能和特性,分析了今后塑料增韧增强发展的方向。     

基于多分量融合的调度端小电流接地选线策略

针对中性点不接地的配电系统站端接地选线方式投资大、维护成本高,零序电流采样监测运行维护困难的问题,提出一种基于多分量融合的调度端小电流接地选线方法。首先,在现有调度自动化系统监测数据集中,针对性分析了对接地故障较为敏感的单分量特征及其影响因素;其次,综合考虑实际运行可靠性和判断准确性,提出了基于三角模融合的接地选线判据;进而通过归一化计算各线路接地概率,实现在调度端远程的故障线路准确选线;最后,通过在某电力公司实际部署基于所提方法的小电流接地选线功能模块进行实测验证。运行结果显示,所提方法具有良好的选线成功率,能够较好支撑调度端的远程故障定位,具有较高的推广价值。     

考虑元件耐受性的电网关键元件辨识

在历次大停电事故过程中,电网中存在少量元件对事故的演化发展起到关键性作用。为此,本文提出一种综合元件耐受性与重要性的电网元件关键性评估方法。从电网元件对电网电能传输影响的角度来衡量电网元件的重要性,分别定义了输电线路的潮流分布影响熵和节点电压影响熵;从引发电网元件失效的主导因素出发来衡量电网元件的耐受性,分别定义了输电线路在N-1准则下和节点在负荷波动下电网元件的耐受性指标;将耐受性指标与重要性指标综合来进行电网元件的关键性评估。最后,利用IEEE 39节点系统算例验证了所提方法的有效性。