火电机组碳排放量及碳敏感性通用矩阵模型

为实现火电机组碳排放量的简便准确计量及掌握运行因素对机组碳排放强度的影响,在排放因子法技术上,参考传统q-γ-τ矩阵结构形式,根据求解火电机组碳排放量的需要,并掌握运行参数对发电碳排放强度的影响,建立了火电机组碳排放量及碳敏感性通用矩阵模型,确定了矩阵填写规则。采用热平衡法结合物料衡算法验证了模型的准确性,并与排放因子法核算结果对比;核算了某火电机组24 h的碳排放量,分析了排烟氧量、主蒸汽温度和压力波动时的发电碳排放强度的扰动量ΔM CO_(2)。结果表明:相较于排放因子法,本文所提模型缩短了碳排放量核算的时间跨度,且能提高碳排放量核算的精度;该机组24 h的碳排放量为5780.644 t;当排烟氧量降低0.1%时,ΔM CO_(2)为1.7726 g/(kW·h);当主蒸汽温度升高0.5 K时,ΔM CO_(2)为3.0206 g/(kW·h);当主蒸汽压力增加0.2 MPa时,ΔM CO_(2)为0.3788 g/(kW·h)。

TechImp局放脉冲信号分离与识别研究

通过对TechImp公司高频局部放电检测仪PDCheck在新疆电力系统中的现场应用,利用高频局部放电检测技术检测和分析电力变压器、电力电缆附件、电流互感器、电压互感器及避雷器等高压电气设备绝缘缺陷;利用局部放电高频信号并借助分析软件和专家系统对设备缺陷进行诊断,能有效抑制现场复杂的干扰信号以正确判断放电类型及放电强度;实践表明,采用高频局部放电现场检测能对设备运行状态进行有效评估,为实现电气设备的状态检修提供了物质基础。

Porosity Determination Equation for Porous Silicon

Through the studying of the carriers moving of the porous and the definition of S BET ,the equation of the relationship among the porosity,the current density and the etching speed can be deduced.Here,it is shown that for porous silicon made from p type silicon,there is a universal relationship,it is possible to determine the change in porosity with respect to etching under a set etching current density.This relationship is checked against experimental data from several reports on these etching parameters,and they confirm the validity.

Peculiarities of the C2 Swan Band System Intensities in Gas Discharges through CO-Contained Mixtures

The paper discusses the experimental results pointing to the efficient channel of the CO vibrational to the C2 electronic energy-transfer. The radiation spectra of the d3Hg electronic state of C2 molecule are investigated and the relation of their kinetics to a vibrational excitation of CO molecules in the He-CO-O2 plasma is discussed. The changes of CO VED （vibrational energy distribution） were imposed by an application of a laser resonator to the discharge tube under investigation. Strong correlation has been found in experiments between concentrations of vibrationally excited CO molecules and the electronically excited state d31qg of C2 molecule. Modulation of the intensity of lasing oscillation cased marked modulation of the intensity of the emission from d3Hg （Swan bands）. It was found that the vibrational levels 12 〈 w 〈 20 of the CO molecules most effect on the concentration of the C2 （d3flg）. The facts discussed above most probably point to the existence of efficient channel for the VE energy transfer： CO （w） ＋ C2 →CO ＋ C2 （d3II）. The efficiency of this channel increases with the growth of populations of high vibrational levels of CO （X1∑, w）.

电力碳排放强度的基本概念及其研究进展

“双碳”已经成为国家战略,国家有关部委对碳排放统计核算计量发布一系列政策,提出了明确的工作需求。量化计算电力碳排放强度可以准确掌握我国各个地区的碳排放变化趋势,并开展有针对性的各项碳减排工作以促进绿色经济转型。我国虽然已初步建立了一套碳排放计量方法,并以年为单位开展碳消费清单的核算工作,但该方法的理论体系仍相对落后,在统计能源碳消费层面会产生较大偏差,且核算周期过长,核算结果缺乏时效性,使相关企业对我国发布的碳排放清单核算数据的权威性产生疑问,因此,碳核算工作的机制亟须完善。提出了一种分时分区电力碳排放强度的核算体系,利用电力状态估计和潮流特性,构建电网发用电侧碳排放量的耦合关联计算方法,定义发用电碳排放强度,提出考虑电能替代的区域与边际碳排放强度计算方法,以及采用电力碳排放强度体现绿电交易中的区域碳强度变化,最后探讨了基于图计算的分时分区电力碳排放强度的先进性。

适用于电磁暂态仿真的大电网简化方法及在南方电网的应用

为了减少采用电磁暂态仿真程序研究大规模交直流电力系统中交流系统不对称故障时的计算量,提出了采用发电机支撑强度进行动态等值的方法。根据500 k V主干网架母线与低压网络拓扑结构以及低压网络是否含有发电机分别采用3种标准等值结构替代;其次采用时域聚合法得到等值发电机参数;最后针对动态等值结果评价提出3个量化指标。该文对南方电网2020年规划数据进行等值计算,比较了等值前后主干网架的稳态潮流、短路电流水平和暂态响应特性。比较结果表明,该等值方法既能保证等值前后主干网架稳态潮流不变,又能保证短路电流近似不变;等值系统极大简化原型系统的同时,保持了一定的动态响应相似性。

Wind Tunnel Study on Wind and Turbulence Intensity Profiles in Wind Turbine Wake

In recent years, there has been a rapid development of the wind farms in Japan. It becomes very important to investigate the wind turbine arrangement in wind farm, in order that the wake of one wind turbine does not to interfere with the flow in other wind turbines. In such a case, in order to achieve the highest possible efficiency from the wind, and to install as many as possible wind turbines within a limited area, it becomes a necessity to study the mutual interference of the wake developed by wind turbines. However, there is no report related to the effect of the turbulence intensity of the external flow on the wake behind a wind turbine generated in the wind tunnel. In this paper, the measurement results of the averaged wind profile and turbulence intensity profile in the wake in the wind tunnel are shown when the turbulence intensity of the external wind was changed. The wind tunnel experiment is performed with 500mm-diameter two-bladed horizontal axis wind turbine and the wind velocity in wake is measured by an I-type hot wire probe. As a result, it is clarified that high turbulence intensities enable to the entrainment of the main flow and the wake and to recover quickly the velocity in the wake.

Ultrafast exciton relaxation dynamics of PbS and core/shell PbS/CdS quantum dots

Optical properties and ultrafast exciton relaxation dynamics in PbS and core/shell PbS/CdS quantum dots(QDs) have been studied using UV-vis absorption and fluorescence spectroscopy as well as femtosecond(fs) transient absorption spectroscopy.The electronic absorption spectrum of the PbS QDs features broad absorption in the entire near IR-vis-UV region with a monotonic increase in intensity towards shorter wavelength.Relative to PbS,the absorption of the core/shell PbS/CdS QDs shows a slight blue shift in the 600?800 nm region,due to the decrease of the PbS crystal size caused by the synthetic process of the core/shell structure,and increased absorption near 400 nm due to the CdS shell.The PL of the PbS/CdS QDs was ~2.6 times more intense than that of the PbS QDs,due to surface passivation of PbS by CdS,and blue-shifted,attributable to smaller PbS size and thereby stronger quantum confinement in the core/shell QDs.Fs transient absorption measurements of both systems showed a strong transient absorption feature from 600 to 750 nm following excitation at 750 nm.The transient absorption decays can be fit to a biexponential with time constants of 8 and 100 ps for PbS and 6 and 80 ps for PbS/CdS.The amplitude and lifetime of the fast component were excitation intensity dependent,with the amplitude increasing more than linearly with increasing excitation intensity and the lifetime decreasing with increasing intensity.The fast decay is attributed to exciton-exciton annihilation and it occurs more readily for the PbS/CdS than the PbS QDs,which is attributed to a lower density of trap states in the core/shell QDs,as supported by their stronger PL.

Full-temperature covered switching material with triple optic-dielectric states in a lead-free hybrid perovskite

Optic-electric responsive materials have attracted much attention for their applications in temperaturesensing,actuators,and memory switches.However,it is a challenge to integrate various functions to form multifunctional responsive materials.As molecule-based hybrid materials usually consist of organic and inorganic components,the introduction of multiple functions can be achieved through structural construction.Thus far,even though fulltemperature cover is required for device applications,fulltemperature covered multi-switchable hybrid materials have rarely been successfully synthesized.Herein,the dynamic[(CH3)3NOH]+cation and luminous center Mn(II)were introduced to form a hybrid material[(CH3)3NOH][Mn Cl3],showing multiple temperature-responsive behaviors.Upon temperature change,it exhibits multi-state dielectric switching response and intensity or peak shift response of luminous in full-temperature range(low,room,and high temperatures).These responsive behaviors are triggered by the motion or reorientation of[(CH3)3NOH]+cations and inorganic framework.Overall,the switchable photoelectric material has potential applications in multiple encrypted storage and sensor devices.

Study on the fluorescence quenching of ZnO by graphene oxide

Zinc oxide（ZnO） microrod arrays were synthesized on Si substrate by a vapor phase transport（VPT） method in a tube furnace.The obtained ZnO microrods are characterized by scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The photoluminescence（PL） measurement indicates that the ZnO microrods have a strong ultraviolet（UV） emission centered at ~391 nm and a defect-related emission centered at ~530 nm.After the microrods were coated with graphene oxide（GO）,the PL intensity of the hybrid microstructure is quenched compared with that of the bare one at the same excitation condition,and the PL intensity changes with the concentration of the GO.The fluorescence quenching mechanism is also discussed in this work.