光储微网的储能优化配置与技术经济分析

在储能系统和光伏发电相结合的统筹规划中,电池储能投资成本、光伏装机容量、光伏并网价格以及热电联产(CHP)的采用对电池储能的容量配置和电池充放电策略具有显著影响。基于分时电价下的光伏储能系统,将电池储能的容量和功率的配置转化为根据电价时段划分的约束优化问题。以某工业园区为研究对象,建立光伏-储能系统功率流模型,优化计算得到经济效益最优化的电池容量和功率配置结果及电池充放电策略。基于内部收益率、光伏自我消纳率等指标,根据光伏上网价格和电网谷段电价的关系划分场景,通过光伏发电容量和电池价格的变化探究光伏-储能系统中电池储能的容量配置、经济效益的变化规律和热电联产对系统的影响。     

基于动态运行策略的太阳能分布式供能系统设计运行联合优化

提出将光伏剩余电量按照可变比例分配给储能电池及市政电网的动态运行策略,建立基于该策略的并网太阳能分布式供能系统设计运行联合优化模型,在不同分时电价下基于遗传算法对模型寻优,并将动态运行策略与对照运行策略（剩余电量优先并网或优先分配储能电池）下的系统运行结果进行比较分析。以陕西某乡村典型民居建筑为例进行分析,结果表明：1）分时电价的峰谷价差较大时,动态运行策略可有效降低太阳能分布式供能系统成本;2）分时电价的峰谷价差对于动态运行策略下储能电池的容量配置具有较大影响：峰谷价差越大,储能电池的配置容量越大;3）光伏度电补贴对3种运行策略下的系统成本影响程度为：动态运行策略>策略B（剩余电量优先分配储能电池）>策略A（剩余电量优先并网）。     

风光互补独立供电系统的优化设计

在设计风光互补独立供电系统时,系统中需要优化的不仅有光伏电池和蓄电池的容量,还应该有风力发电机种类和容量以及光伏电池的倾角。优化目标为系统安装成本,约束条件为供电可靠性,其指标负载缺电率LP- SP需经仿真运行得到。本问题属于非线性整数规划,也是一个NP-hard问题。用包含精英策略的遗传算法优化,以自适应罚函数法处理约束。计算和验证表明本文采用的算法收敛,能同时优化风力发电机类型和容量、光伏电池的容量和倾角以及蓄电池的容量,并且计算效率高。     

独立光伏发电系统的能量优化管理

提出了一个由光伏电池、蓄电池、单向DC-DC变换器和双向DC-DC变换器组成的独立光伏发电系统。为了在不同的工作条件下使直流母线电压稳定,采用一种光伏发电系统的协调控制策略,对系统能量进行管理,使光伏电池和蓄电池协同工作。通过Matlab仿真证明了所提出的控制策略的正确性与可行性。     

计及储能系统的微电网优化调度模型

为了缓解含风电、光伏等新能源微网并网对系统安全运行的影响,提出了在分时电价下,考虑储能系统的微网优化调度策略。以微网总成本最低为目标,分别考虑了投资成本、污染惩罚成本及主网购电成本,建立了微网主网联合运行优化模型,并以典型日负荷出力情况为例分析了不同情景下的优化结果。算例结果表明,所提策略和模型能有效实现微网优化调度,有效降低了含电动汽车和蓄电池等储能设备的微网年运行成本,同时能够保障微网和主网的联合安全运行。     

考虑时段耦合的带有蓄电池的用户光伏系统优化运行研究

考虑到光伏出力、负荷变化以及电价都有明显的以一天为周期的变化规律,建立以天为一个运行优化周期,一天内又可分为任意多个时段的带有时段耦合的配蓄电池的用户光伏系统的运行优化模型。该模型在整个优化周期表现为非线性模型或分段线性模型,通过控制变量分拆的方法将其改造为等价全局线性模型,以便运用高效快捷的线性规划单纯形算法对其求解。与非线性模型在相同条件下进行比较,该模型不仅可在分时电价、实时电价下得出最佳运行方案,更重要的是在运算时间上也有极强优势,所以不但可用于日前优化方案的制定,也可用超短时优化方案的制定。最后在某省现行分时电价下应用该模型预测了蓄电池配在光伏系统中可实现盈利的折旧费或投资成本。     

计及蓄电池使用寿命的热电联供型微电网经济优化

热电联供型微电网与当前能源互联网发展联系紧密,具有经济、节能、环保等优点。为了使热电联供系统的经济模型计算更加精确,文章在微电网经济调度优化模型中,考虑了蓄电池充放电深度和荷电状态SOC对蓄电池寿命的影响,利用加权吞吐量法计算其运行成本,建立了含风电机组、光伏电池、储能系统、燃料电池、空调机以及热电联供的并网型微电网系统的日运行成本优化模型,采用改进型遗传算法优化各微源出力,使其日运行成本最小。通过仿真算例,验证了考虑蓄电池使用寿命的微电网运行成本模型更符合实际运行工况。     

太阳能布雷顿循环耦合蓄电池平抑光伏输出波动策略研究

为研究太阳能布雷顿循环耦合蓄电池平抑光伏输出功率波动性策略问题,建立了光伏-光热-蓄电池联合发电系统,以光伏为主要出力,太阳能空气布雷顿循环和蓄电池为辅稳定光伏输出功率波动,并根据微燃机高效运行方式及联合发电系统变负荷方式提出了4种运行策略。结果表明：4种策略均能在一定程度上降低光伏输出功率波动性,且在相同蓄电池容量下,策略二光伏输出功率波动性最小,策略三蓄电池最大充电功率最小;随着蓄电池容量的增加,4种策略光伏输出功率波动性均在减少,并且策略二和策略一在平抑输出功率波动性能力上不断接近;在储热与储电容量比例为3∶4时,策略一～策略四相对仅光伏运行时的输出功率波动性分别减少了80.7%、88.3%、50.5%和55.1%。     

动态电价下分布式光伏-储能系统优化与经济性分析

基于无政策补贴和上网电价研究背景,该文采用提高光伏微网自用且兼顾系统经济性的储能控制策略,分析了不同动态电价定价方案、储能容量和单位容量成本对光伏-储能系统经济性的影响.以长沙某办公建筑为例,采用动态规划求解系统年最佳运行策略并计算系统生命周期经济性和光伏自消耗率,结果表明动态电价每提高41.5％,系统盈利可行域提高8...     

电力市场环境下槽式太阳能热发电系统配置优化设计方法研究

通过建立全年时段槽式太阳能热发电系统运行的线性规划模型,提出槽式太阳能热发电系统太阳倍数和储热时长优化选取的方法,并考虑了电力市场环境下负荷和光伏发电出力波动对电价的影响因素。通过实际算例分析不同的分时电价曲线下最佳集热场面积和储热容量的选取,以及其设计参数选取对发电项目年利用小时数和收益的影响。     

Optical properties and thermal stability of pulsed-sputter-deposited AlxOy/Al/AlxOy multilayer absorber coatings

Spectrally selective Al_xO_y/Al/Al_xO_y multilayer absorber coatings were deposited on copper (Cu) and molybdenum (Mo) substrates using a pulsed sputtering system. The Al targets were sputtered using asymmetric bipolar-pulsed DC generators in Ar+O₂ and Ar plasmas to deposit an Al_xO_y/Al/Al_xO_y coating. The compositions and thicknesses of the individual component layers were optimized to achieve high solar absorptance (α=0.950-0.970) and low thermal emittance (ε=0.05-0.08). The X-ray diffraction data in thin film mode showed an amorphous structure of the Al_xO_y/Al/Al_xO_y coating. The X-ray photoelectron spectroscopy data of the Al_xO_y/Al/Al_xO_y multilayer absorber indicated that the Al_xO_y layers present in the coating were non-stoichiometric. The optical constants (n and k) of the multilayer absorber were determined from the spectroscopic ellipsometric data. Drude's free-electron model was used for generating the theoretical dispersion of optical constants for Al films, while the Tauc-Lorentz model was used for modeling optical properties of the dielectric Al_xO_y layers. In order to study the thermal stability of the Al_xO_y/Al/Al_xO_y coatings, they were subjected to heat treatment (in air and vacuum) at different temperatures and durations. The multilayer absorber deposited on Cu substrates exhibited high solar selectivity (α/ε) of 0.901/0.06 even after heat-treatment in air up to 400 °C for 2 h. At 450 °C, the solar selectivity decreased significantly on Cu substrates (e.g., α/ε=0.790/0.07). The coatings deposited on Mo substrates were thermally stable up to 800 °C in vacuum with a solar selectivity of 0.934/0.05. The structural stability of the absorber coatings heat treated in air (up to 400 °C) and vacuum (up to 800 °C) was confirmed by micro-Raman spectroscopy measurements. Studies on the accelerated aging tests suggested that the absorber coatings on Cu were stable in air up to 75 h at 300 °C and the service lifetime of the multilayer absorber was predicted to be more than 25 years. Further, the activation energy for the degradation of the multilayer absorber heat treated for longer durations in air is of the order of 64 kJ/mol.     

Hydrogen storage properties of multi-principal-component CoFeMnTixVyZrz alloys

This study presents an innovative multi-principal-element CoFeMnTiVZr alloy system for the absorption and desorption of hydrogen. Pressure-composition-isotherms (PCIs) demonstrate that CoFeMnTi_xVZr, CoFeMnTiV_yZr, and CoFeMnTiVZr_z can absorb and desorb hydrogen for x, y, and z that satisfy 0.5 ≤ x ≤ 2.5, 0.4 ≤ y ≤ 3.0, and 0.4 ≤ z ≤ 3.0, respectively. X-ray diffraction (XRD) reveals that CoFeMnTi_xV_yZr_z alloys have a simple C14 Laves phase with a single set of lattice parameters before and after PCI tests. The distributions of each element in CoFeMnTi_xV_yZr_z alloys are roughly equal, as revealed by SEM/EDS mapping. The effects of values x, y, and z on the hydrogen storage properties are elucidated in terms of lattice constant, element segregation, hydride formation enthalpies of the alloy components and hydrogen, and the averaged formation enthalpy. The high-entropy effect promotes the formation of a single C14 Laves phase, and the maximum hydrogen storage capacity is strongly related to the hydride formation enthalpy of the alloy and hydrogen.     

Explosion behavior of CH4/O2/N2/CO2 and H2/O2/N2/CO2 mixtures

In this work, the explosion behavior of stoichiometric CH₄/O₂/N₂/CO₂ and H₂/O₂/N₂/CO₂ mixtures has been studied both experimentally and theoretically at different CO₂ contents and oxygen air enrichment factors. Peak pressure, maximum rate of pressure rise and laminar burning velocity were measured from pressure time records of explosions occurring in a closed cylindrical vessel. The laminar burning velocity was also computed through CHEMKIN–PREMIX simulations.     

C/H/O/N/S/Cl/K/Na元素的详细化学反应机理的简化与验证

基于Senkin模型,应用自编化学反应机理简化程序,结合Kinalc和Mechmod开源程序,发展了详细化学反应机理的简化与验证方法.以电站锅炉燃烧的计算流体力学(CFD)数值模拟为应用背景,建立了考虑C/H/O/N/S/Cl/K/Na元素的详细化学反应机理(115组分,1,342基元反应),并运用此方法得到简化反应机理(28组分,20反应).验证结果表明,该简化机理在锅炉运行的主要参数变化范围内(温度T=1,100～1,500,℃,过量空气系数λ=0.8～1.2)具有较好的准确性和较高的计算效率,可应用于锅炉燃烧的CFD计算.     

Structural and transport properties of LixNi1−y−zCoyMnzO2 cathode materials

In this work structural and transport properties of layered LiNi_1−y−zCo_yMn_zO₂ (y = 0.25, 0.35, 0.5 and z = 0.1) cathode materials are presented. In the considered group of oxides, LiNi_1−y−zCo_yMn_zO₂, there is no clear correlation between electrical conductivity and the a parameter (M-M distance in the octahedra layers). A non-monotonic modification of electrical properties of Li_xNi_0.65Co_0.25Mn_0.1O₂ cathode materials is observed upon lithium deintercalation.     

Metal/CdTe/CdS/Cd1−xZnxS/TCO/glass: A new CdTe thin film solar cell structure

The potential of CdTe/CdS/Cd_1−xZn_xS structure as an alternative to CdTe/CdS structure in photovoltaic application has been demonstrated. The unoptimized solar cell structure grown on transparent conducting oxide coated soda lime glass of 3 mm thickness with no antireflection coating yielded a 10% efficiency. This efficiency is the highest ever recorded in any Cd_1−xZn_xS film containing CdTe solar cells.     

Preparation and electrochemical properties of layer-structured LiNi1/3Co1/3Mn1/3−yAlyO2

Layer-structured LiNi_1/3Co_1/3Mn_1/3−yAl_yO₂ has been synthesized via a sol–gel method. The lattice constants of LiNi_1/3Co_1/3Mn_1/3−yAl_yO₂ decrease with the concentration of aluminum ions. XANES analysis further confirms that the valence of cobalt ion is 3+, and that of Ni is between 2+ and 3+ in LiNi_1/3Co_1/3Mn_1/3−yAl_yO₂. With doping aluminum ions, the redox centers for the electrochemical reaction change from nickel ions alone to both nickel and cobalt ions. The amounts of de-intercalatable lithium ions are affected by the concentration of aluminum ions; however, the extracting efficiency of lithium ions is improved by doping aluminum ions. Among all the samples, LiNi_1/3Co_1/3Mn_0.23Al_0.1O₂ exhibits the best capacity retention and the least irreversible capacity.     

Experimental and modeling studies of C2H4/O2/Ar, C2H4/methylal/O2/Ar and C2H4/ethylal/O2/Ar rich flames and the effect of oxygenated additives

The addition of dimethoxymethane (DMM or methylal) and diethoxymethane (DEM or ethylal) to a rich ethylene/oxygen/argon flame has been investigated by measuring the depletion of soot precursors. Three rich premixed ethylene/oxygen/argon (with and without added methylal or ethylal) flat flames have been stabilized at low-pressure (50 mbar) on a Spalding–Botha type burner with the same equivalence ratio of 2.50. Identification and monitoring of signal intensity profiles of species within the flames have been carried out by using molecular beam mass spectrometry (M.B.M.S.). The replacement of some C₂H₄ by C₃H₈O₂ or C₅H₁₂O₂ is responsible for a decrease of the maximum mole fractions of the detected intermediate species. This phenomenon is noticeable for C₂–C₄ intermediates and becomes more effective for C₅–C₁₀ species, mainly when C₃H₈O₂ added.A new kinetic model has been elaborated and contains 546 reactions and 107 chemical species in order to simulate the three investigated flames: C₂H₄/O₂/Ar, C₂H₄/DMM/O₂/Ar and C₂H₄/DEM/O₂/Ar. The reaction mechanism well reproduces experimental mole fraction profiles of major and intermediate species, and underlines the effect of methylal and ethylal addition on species concentration profiles for these flames.     

Highly structured TiO2/In(OH)xSy/PbS/PEDOT:PSS for photovoltaic applications

A system of highly structured TiO₂/In(OH)_xS_y/PbS/PEDOT:PSS has been developed and investigated by photovoltage spectroscopy, X-ray photo- and Auger electron spectroscopies, electron microscopy, and photovoltaic response. TiO₂, In(OH)_xS_y, PbS, and PEDOT:PSS serve as electron conductor, buffer layer, absorber, and hole conductor, respectively. Both buffer and absorber layers were prepared by chemical bath deposition. The band gap of as-prepared In(OH)_xS_y varied between 2.4 and 3.5 eV depending on the pH-value of the solution. In addition, the band gap of the PbS could be widened to about 0.85 eV making the application as absorber for solar cells feasible. At present, corresponding solar cell devices reach short-circuit current densities of about 8 mA/cm² and open-circuit voltages of about 0.3 V.     

Burning velocities and kinetics of H2/NF3/N2, CH4/NF3/N2, and C3H8/NF3/N2 flames

The combustion characteristics and reaction mechanism of mixtures containing nitrogen trifluoride (NF₃) were investigated. Burning velocities for H₂/NF₃/N₂, CH₄/NF₃/N₂, and C₃H₈/NF₃/N₂ flames were determined for the first time at various equivalence ratios and N₂ mole fractions. The burning velocities of the latter two flames were similar and showed peaks at equivalence ratios of ∼1.0, while those of the H₂/NF₃/N₂ flames had the pronounced peak at low equivalence ratios where the formation of the wrinkled flames was observed. A detailed kinetic model was constructed to simulate the laminar burning velocities of H₂/NF₃/N₂ and CH₄/NF₃/N₂ flames. The model accurately reproduced the experimental results. Analyses of the reaction mechanism revealed the major reaction pathways that involve the decomposition of NF₃, the oxidation and chain-fluoridation of H₂ and CH₄, and the formation of N₂.