Evaluation of the Performance of Lithium-Ion Accumulators for Photovoltaic Energy Storage

In a context of climate change exacerbated by the increasing scarcity of fossil fuels, renewable energies, in particular photovoltaic solar energy, offer a promising alternative. Solar energy is non-polluting, globally available and the most widely distributed resource on Earth. However, the intermittency of this energy source considerably limits its expansion. To solve this problem, storage techniques are being used, in particular, electrochemical storage using lithium-ion batteries. In this article, we will evaluate the performance of lithium-ion batteries when integrated into a photovoltaic grid. To do this, modelling and simulation of a photovoltaic system connected to a lithium-ion battery storage system will be carried out using MATLAB/Simulink software. A diagnostic of the energy consumption of the Kaya Polytechnic University Centre will be carried out, and the data will then be used in the simulator to observe the behaviour of the PV-Lion system. The results obtained indicate that lithium-ion batteries can effectively meet the centre’s energy demand. In addition, it was observed that lithium-ion batteries perform better under high energy demand than the other battery technologies studied. Successive storage systems with the same capacity but different battery technologies were compared. It was found that these storage systems can handle a maximum power of 4 × 105 W for lead-acid batteries, 6.5 × 105 W for nickel-cadmium batteries, 8.5 × 105 W for nickel-metal-hydride batteries, and more than 10 × 105 W for lithium-ion technology.

Theoretical and experimental study of energy transportation and accumulation in femtosecond laser ablation on metals

The energy transportation and accumulation effect for femtosecond(fs)laser ablation on metal targets were studied using both theoretical and experimental methods.Using finite difference method,numerical simulation of energy transportation characteristics on copper target ablated by femtosecond laser was performed.Energy accumulation effects on metals of silver and copper ablated by an amplified Ti:sapphire femtosecond laser system were then studied experimentally.The simulated results show that the electrons and lattices have different temperature evolvement characteristics in the ablation stage.The electron temperature increases sharply and reaches the maximum in several femtoseconds while it needs thousands of femtoseconds for lattice to reach the maximum temperature.The experimental results show that uniform laser-induced periodic surface structures(PSS)can be formed with the appropriate pulsed numbers and laser energy density.Electron-phonon coupling coefficient plays an important role in PSS formation in different metals.Surface ripples of Cu are more pronounced than those of Au under the same laser energy density.

Characteristics of Energy Accumulation and Release of Seismogenic Tectonics and Seismic Risk Analysis in Some Areas in the Tianshan Mountains, Xinjiang

Comparative analysis between the quantitative data of active faults and seismicity reveals that a complete earthquake recurrence cycle includes the characteristic earthquake and the sub-maxima earthquakes in-between. The magnitude of the sub-maxima events is correlated with the elapsed time of the characteristic earthquake and the slip rate of the fault. The fault displacement includes the major stick-slip generated by the characteristic earthquakes and the minor stick-slip by the sub-maxima ones. The magnitude-frequency relationship still works in the complete recurrence cycle. The energy accumulation in the cycle is divided approximately into four phases, and the seismicity differs at each phase. The relation of the maximum displacement with the average displacement of the characteristic earthquake suggests the partitioning of deformation between the characteristic and the sub-maxima earthquakes. Based on the above analysis, relevant mathematical equations are put forward for the quantitative assessment of the potential magnitude and earthquake risk of seismogenic tectonics. Tentative study has been carried out in this aspect in some areas of Tianshan.

A Preliminary Study on Seismicity and Stages of Seismic Energy Accumulation in Seismotectonic Regions of Tianshan

Using seismic parameters, the characteristics of the seismic activity in various seismotectonic regions of Tiaushan were studied in this paper. These regions are going through different stages of seismic energy accumulation. Current seismic risk levels of these areas were analyzed synthetically by the tectonic movement rates, as well as the characteristics of the seismic activity and the recurrence intervals of strong earthquakes. We preliminarily studied the characteristics of seismic activity in different seismic energy accumulating stages. The result shows that the characteristics of the seismic activity in various seismotectonic regions of the Tiaushan area are influenced, not only by the regional tectonic movement, but also by the energy accumulating stage of various seismic tectonics. In the intense tectonic movement areas, it is important to estimate its stage of energy accumulating in order to predict the upper limit of the potential earthquake magnitude. In the less intense tectonic movement areas, the estimating of the stage of energy accumulation will help us recognize the dangerous level of the potential strong earthquake. The study shows that the seismotectonic regions in southern Tiaushan have reached the mid-stage and late-stage of energy accumulation, with a higher seismic activity and thus a higher seismic dangerous level than those in the northern and middle Tiaushan. The earthquake risk of southern Tianshan is up to Ms7.0, while that of the middle Tiaushan is up to Ms6.0 and that of northern Tiaushan is only around Ms5.0 - 6.0.

Buoyance-driven hydrocarbon accumulation depth and its implication for unconventional resource prediction

The discovery of unconventional hydrocarbon resources since the late 20th century changed geologists’understanding of hydrocarbon migration and accumulations and provides a solution to energy shortage.In 2016,unconventional oil production in the USA accounted for 41%of the total oil production;and unconventional natural gas production in China accounted for 35%of total gas production,showing strong growth momentum of unconventional hydrocarbons explorations.Unconventional hydrocarbons generally coexist with conventional petroleum resources;they sometimes distribute in a separate system,not coexisting with a conventional system.Identification and prediction of unconventional resources and their potentials are prominent challenges for geologists.This study analyzed the results of 12,237 drilling wells in six representative petroliferous basins in China and studied the correlations and differences between conventional and unconventional hydrocarbons by comparing their geological features.Migration and accumulation of conventional hydrocarbon are caused dominantly by buoyance.Wepropose a concept of buoyance-driven hydrocarbon accumulation depth to describe the deepest hydrocarbon accumulation depth driven dominantly by buoyance;beyond this depth the buoyance becomes unimportant for hydrocarbon accumulation.We found that the buoyance-driven hydrocarbon accumulation depth in petroliferous basins controls the different oil/gas reservoirs distribution and resource potentials.Hydrocarbon migration and accumulations above this depth is dominated by buoyancy,forming conventional reservoirs in traps with high porosity and permeability,while hydrocarbon migration and accumulation below this depth is dominated by non-buoyancy forces(mainly refers to capillary force,hydrocarbon volumeexpansion force,etc.),forming unconventional reservoirs in tight layers.The buoyance-driven hydrocarbon accumulation depths in six basins in China range from 1200mto 4200 m,which become shallowerwith increasing geothermal gradient,decreasing particle size of sandstone reservoir layers,or an uplift in the whole petroliferous basin.The predicted unconventional resource potential belowthe buoyance-driven hydrocarbon accumulation depth in six basins in China is more than 15.71×10^(9) t oil equivalent,among them 4.71×10^(9) t reserves have been proved.Worldwide,94%of 52,926 oil and gas reservoirs in 1186 basins are conventional reservoirs and only 6%of them are unconventional reservoirs.These 94%conventional reservoirs show promising exploration prospects in the deep area below buoyance-driven hydrocarbon accumulation depth.

Peak Load Evaluation Based on the Accumulated Annual Energy

This paper presents a nonlinear approach to estimate the consumed energy in electric power distribution feeders. The proposed method uses the statistical solution algorithm to analyze the active energy monthly consumption, which enables one to estimate the energy consumption during any period of the year. The energy readings and the normalized accumulated energy profile are used to estimate the hourly consumed active power, which can be used for future planning and sizing the equipment of the electrical system. The effectiveness of the proposed method is demonstrated by comparing the simulated results with that of real measured data.

阿根廷滑柔鱼能量积累的食物组成及其生态角色的研究进展

阿根廷滑柔鱼(Illex argentinus)是生长速度快、终生一次繁殖产卵、生命周期短的大洋浅海性头足类,也是世界上重要的经济物种。在西南大西洋生态系统中,阿根廷滑柔鱼发挥着重要的“生物泵”作用。在短暂的生命周期里,阿根廷滑柔鱼具有索饵–生殖洄游的生活史特征,并采取收入–资本混合型的生殖投入策略,即以现场摄食饵料吸收转化的能量投入为主、肌肉存储能量投入为辅。在不同的栖息海域与生长发育阶段,阿根廷滑柔鱼具有不同的食物组成。本文扼要概述阿根廷滑柔鱼的组织能量积累特点、能量积累过程的食物组成变化以及在西南大西洋生态系统中作为能量传输者的生态角色。同时,探讨了阿根廷滑柔鱼能量积累需求与洄游、摄食策略的关系,并对阿根廷滑柔鱼作为海洋食物网能量传输者的生态角色在气候变化、渔业活动背景下的变化做了展望分析,可为持续开发该种类资源提供资料参考。

川滇主要断裂带应力应变积累速率的三维有限元模拟:初步结果

川滇地区构造活动强烈,活动断裂众多,强震活动频繁.了解主要活动断裂的应力应变积累速率对于评估该区的长期地震危险性具有重要参考作用.本文新建立川滇地区及其主要活动断裂的三维黏弹性有限元模型,其中考虑了该区的岩石圈结构分层以及介质在水平和深度方向的不均匀性;采用1996—2018年的平均GPS水平速度场约束模型的侧边界,同时考虑川滇地块深部介质的拖曳力过程,模拟计算了构造加载作用下模型的动力学响应——区域变形特征和断裂的应力积累速率.模拟的位移场能很好拟合GPS观测的速度场,模拟的水平主应力方向在川滇块体和华南块体西缘与地震震源主应力方向相符,反映所建模型与模拟结果有较好的可信度.尝试将模拟的应力积累速率与基于GPS/GNSS观测的应变速率相结合,计算能反映区域地壳应变积累程度的弹性应变能密度分布;讨论了主要断裂带的背景应力、弹性应变能密度和库仑应力积累速率与M≥6.0地震发生的关系.结果显示除了模型边界附近的应力奇异地带外,川滇其余地区1996年以来M≥6.0地震大多数发生在模拟应力积累速率高或次高的断裂带(段),以及弹性应变能密度积累速率中偏高的断裂带(段).在模拟的背景应力速率高而且库仑应力增长快的龙门山断裂带南段和鲜水河断裂带最南段,分别在本文写作和定稿阶段发生2022年6月1日四川芦山M6.1地震和2022年9月5日四川泸定M6.8地震.认为研究区具有类似高或者次高的模拟应力和弹性应变能密度积累速率、但至今无强震发生和记录的断裂带(段),潜在的地震危险性需要关注.

煤厚变化区围岩能量积聚规律及开采方向对其影响

为揭示煤厚变化区围岩能量积聚规律以及开采方向对其影响,以鹤岗峻德煤矿17~#煤层冲击倾向性煤层为研究背景,以组合岩层为对象,探讨了煤厚变化区应力转移机制,揭示了煤厚变化区原岩应力与煤岩厚度比、弹性模量比之间关系,阐明了开采方向对煤厚变化区采动应力及能量积聚规律的影响。结果表明:由于岩石和煤的强度(刚度)差异,导致煤厚变化区域主应力分布不均匀,在煤厚变薄区域出现峰值应力,变厚区域出现谷值应力,且煤厚变化范围越大、煤岩弹性模量比越小,峰值应力越大,谷值应力越小;受采动应力影响,在煤厚变化区域超前支承压力与煤厚变化异常应力叠加,围岩应力集中程度高;由薄向厚回采,工作面前方超前支承压力区和应力异常区叠加,存在1个冲击危险区,由厚向薄回采存在2个冲击危险区,从而由薄向厚回采更为合理。针对煤厚变化区采动应力及能量积聚规律,提出调控采场围岩结构、围岩应力、增加冲击阻能的防控思路,并进行工程应用,效果良好。

飞轮储能蓄能器挖掘机动臂设计及负载特性分析

对飞轮储能蓄能器进行分析,在动臂驱动系统中加入了蓄能器以及轴向柱塞马达,以实现储存更多挖掘机动臂能量和节能控制的效果。研究利用速度传感器把测试得到的负载速度信号传输到比较器中,根据检测数据完成柱塞马达排量的实施调节功能,最终达到稳定的运行速度。研究结果表明:挖掘机阀控系统中选择一个循环下的液压执行元件进行能量利用率分析,执行元件的能量利用率达到了主泵输出的近81%,动臂能量回收占比为17.5%,回转机构的能量回收比例达到主泵输出能量8.9%。负载从位移为0的初始状态发生线性增大,表现出了稳定的运动性能,最终达到2.8 m的位移。环形活塞的压力与位移之间呈现线性变化的特征。位移由0提高到172 mm,压力则由2.1 MPa提高到3.2 MPa,实现了稳定的控制性能。

基于养正除积法运用杵针治疗肝郁脾虚型卒中后抑郁临床观察

目的研究基于养正除积法探讨杵针对肝郁脾虚型卒中后抑郁患者的影响。方法选择2021年3月—2022年3月广东省第二中医院脑病科门诊和病房收治的肝郁脾虚型卒中后抑郁患者80例,随机分为试验组和对照组,每组40例。对照组采用基础治疗结合草酸艾司西酞普兰治疗,试验组采用基础治疗结合杵针治疗,比较两组临床效果、汉密尔顿抑郁量表(HAMD)评分、脑卒中影响量表(SIS)评分及治疗依从性。结果试验组患者治疗总有效率为92.50%(37/40),高于对照组的75.00%(30/40),差异有统计学意义(P<0.05)。治疗后,试验组HAMD评分低于对照组,SIS评分及治疗总依从性高于对照组,差异有统计学意义(P<0.05)。结论基于养正除积法的杵针治疗可有效缓解肝郁脾虚型卒中后抑郁患者抑郁情绪,提高患者生活质量。

面向动臂势能再生的主动式储能元件控制策略

主动式储能元件是一种针对现有液压蓄能器不足而提出的新型气-电混合型储能元件,但其存在着液压能、压缩气体能和电能间的能量耦合问题,导致其工作时抗干扰能力较差,降低了工作液压系统的节能效率。为了解决其存在抗干扰能力差的问题,针对液压挖掘机动臂液压回路的工作特点,提出了利用主动式储能元件实现动臂势能再生的系统架构,并设计了一种自抗扰控制策略及其参数优化方法,通过设计扩张状态观测器来解决干扰和参数不确定性等问题。为验证控制策略的可行性,首先介绍了主动式储能元件的结构;其次,设计了以主动式储能元件为控制对象的自抗扰控制器。建立了基于主动式储能元件的动臂势能再生系统仿真模型,并进行了试验验证。研究结果表明,蓄能器模式、普通控制模式及自抗扰控制模式的回收效率分别为42.81%、56.76%和58.60%;再利用效率分别为96.01%、97.06%和95.81%;再生效率分别为41.1%、55.1%和56.1%。仿真试验验证结果也表明,以主动式储能元件为对象提出的自抗扰控制策略有效地改善了控制性能,增强了系统压力稳定性。

中深层地热地埋管管群换热性能模拟和布置优化

在中深层地热地埋管(DBHE)供热技术应用中,主要使用多个地埋管构成管群为建筑供暖。为了研究中深层同轴地埋管管群换热性能,本文基于西安市西咸新区典型地质分布,构建了中深层同轴地埋管管群数值模型,研究了不同间距、不同分布下各地埋管换热器间热交互作用以及长期取热期水温衰减规律。结果表明,多井集群供暖过程中周围岩土所形成的“冷堆积”现象是导致地埋管集群供暖能力逐年下降的主要原因;当地埋管间距从5m增至25m,平均出口水温和取热功率分别提升3.86%和11.5%;在西咸新区典型地质条件分布下,地埋管间间距应保持在15m以上;本文提出的四种管群分布中,地埋管呈直线分布时各地埋管出口水温和取热功率衰减最小,其中心地埋管出口水温仅衰减5.74%。在工程设计中,中深层地埋管管群应尽可能直线排布,避免重叠排布。

基于双蓄能器切换的非对称泵势能回收系统

针对挖掘机动臂在下落过程中单个蓄能器回收势能效率有限的问题,提出一种高低压双蓄能器切换的能量回收策略。基于能量回收原理,利用计算机仿真软件SimulitionX,根据工作装置的三维结构模型建立3D仿真模型和液压系统仿真模型。在此基础上研究挖掘机工作装置姿态对动臂势能回收效率的影响,对不同作业模式下蓄能器不同压力时的动臂伸缩过程进行模拟分析。最后调查统计了某工地挖掘机某段时间内的作业情况,并进行了计算分析。结果表明:挖掘机在该作业情况下,使用3 MPa和5 MPa的高低压双蓄能器回收能量比使用3 MPa的低压蓄能器效率提升29.23%,比使用5 MPa的高压蓄能器效率提升9.06%。

强威粉TNK对蓄能器橡胶隔膜胶料性能的影响

研究强威粉TNK对蓄能器橡胶隔膜胶料(丁腈橡胶胶料)性能的影响。结果表明:与未添加强威粉TNK的胶料相比,添加强威粉TNK可以提高填料在橡胶基体中的分散性,混炼胶的加工性能更好,硫化胶的拉伸性能、弹性、气密性和耐屈挠性能提高;强威粉TNK用量为8份时,硫化胶拉伸性能、弹性和气密性最好,耐屈挠性能明显提升。

阿根廷滑柔鱼雄性个体的能量积累特点及与环境因子关系

为了掌握阿根廷滑柔鱼(Illex argentinus)雄性个体的能量积累及对栖息环境的适应性,文章利用组织能量密度测定技术,分析了2020—2021年阿根廷滑柔鱼雄性个体肌肉、消化腺和精巢等组织的能量积累及其变化。结果显示,阿根廷滑柔鱼雄性个体的肌肉、消化腺和精巢的组织能量密度分别为(20.15±0.64)、(30.00±2.62)和(19.66±0.33)kJ/g。肌肉组织能量积累占比最大,消化腺次之,精巢的最小;肌肉、消化腺两者的相对能量积累均存在显著的年间差异,精巢的相对能量积累没有年间差异。三个组织的总能量积累与胴长呈正相关关系,肌肉、消化腺的相对能量积累也与胴长呈线性相关关系,而精巢相对能量与胴长没有显著相关性。肌肉和消化腺的相对能量积累均与海底温存在显著效应关系,并且海表温也是影响肌肉相对能量积累的重要环境因子;精巢相对能量积累与栖息海域环境因子没有显著相关性。结果表明阿根廷滑柔鱼雄性个体的能量积累存在组织差异,并且肌肉、消化腺的相对能量积累与个体大小、栖息海域水温密切相关,而精巢组织相对能量积累不因个体大小、栖息海域环境波动变化而变化。研究结果可为阿根廷滑柔鱼能量积累及环境选择适应性的研究提供重要的数据参考。

西白令海夏季狭鳕个体肌肉组织能量密度及其影响因素分析

为了解白令海海域狭鳕(Gadus chalcogrammus)生长发育过程中肌肉组织的能量变化状况,利用2019年和2020年于西白令海拖网采集的112尾狭鳕样本,对其肌肉组织能量密度进行了测量,利用广义加性模型(generalized additive model, GAM)分析了夏季狭鳕个体肌肉组织的能量积累及变化情况,并探究了其影响因素。研究结果显示,体长范围为23.8~60.5 cm的狭鳕肌肉组织的能量密度为(21.10±0.89) kJ·g^(-1),2019和2020年间狭鳕肌肉组织能量密度不存在显著的年际差异(P>0.05)。GAM结果对狭鳕肌肉组织能量密度的解释偏差为46.1%,仅性腺质量和捕捞月份是影响肌肉组织能量密度的两个显著因素,而体长、性腺成熟度等其他指标未对肌肉组织能量密度造成显著影响。相对于性腺成熟度,性腺质量更适于作为生长发育指标来分析狭鳕肌肉能量密度的影响因素。建议应采用多元统计手段开展生物能量累积与能量密度影响分析,以更好地揭示影响能量密度的主要因素。

液压挖掘机液能回收再利用节能装置测控系统

液压挖掘机动臂下降重力势能和回转制动动能均以节流和溢流的形式转化为了油液的热能,严重影响整机能效,亟需提高液压挖掘机液压系统的效率。针对这一问题,提出了基于三腔蓄能器的挖掘机液能回收再利用的节能装置方案,可以回收挖掘机动臂势能和回转制动动能,用于驱动动臂举升。首先,介绍了节能装置的工作原理。其次,设计并开发了节能装置的测控系统,采用CoDeSys编写了下位机控制器程序,直接控制节能装置的动作实现能量回收和再利用;运用C#语言开发了上位机程序进行节能装置电控系统和液压系统的模拟调试和数据监控,并实现了节能装置的远程无线通讯功能。试验结果表明:该测控系统实现了对插装阀开闭和比例节流阀开度的快速、精准控制;达到了对节能装置远程控制和数据实时采集的目标;节能装置的动臂势能回收效率为84.9%,动臂节能效率为52.8%,回转制动工况下的动能回收效率为41.1%。

基于恒压蓄能器非对称缸能量回收及强度校核

针对非对称缸工作装置在下降过程中存在较大的节流损耗问题,采用普通的蓄能器进行回收可以减小系统发热,但是当蓄能器内外压差小时,能量充放效果差,影响作业性能。因此,提出采用恒压蓄能器对非对称缸能量回收系统进行回收与利用,并对所提出的恒压蓄能器隔膜进行强度校核。首先,在Simulation X液压仿真软件中,搭建非对称泵驱动的非对称缸工作装置进行基于恒压蓄能器的能量回收系统仿真;然后,采用基于粒子群算法的并行优化设计方法,对影响回收效率的恒压蓄能器参数进行参数匹配,以提高能量回收效率;最后,对所提出的恒压蓄能器的隔膜进行强度校核与可行性分析。仿真研究结果表明:采用优化后的恒压蓄能器参数进行能量回收的方案,充放压力效果恒定,系统能量回收率达到18.9%。同时所提出的新隔膜方案满足设计强度要求,可为后续的恒压蓄能器的试制提供参考依据。

旋挖钻机主卷扬势能回收系统仿真与研究

针对旋挖钻机主卷扬下放势能难以有效回收与再利用的问题,提出一种主卷扬下放势能回收与利用系统。以某中型旋挖钻机为研究对象,利用AMESim构建了节能系统仿真模型,探究蓄能器的初始工作压力、预充气压力、有效容积等关键参数对系统能量回收效率的影响机制。最后搭建试验样机,通过试验验证了仿真模型和理论分析的正确性。研究结果表明所提出的主卷扬下放势能回收与利用系统重力势能回收效率可达45.53%,节能效果显著。