改进的多级闪蒸发电系统的优化

一、改进的多级闪蒸发电系统 改进的多级闪蒸发电系统(以下简称改进系统)如图1所示其特点是,第l级扩容器之前加设一个汽液分离器,末级扩容器出口的液体排至泵的出口与凝结液混合后进入换     

集成SCO_2动力循环的燃煤电站余热回收系统研究

低温烟气热能的高效梯级利用是火电厂节能减排的重要方向之一。本文结合某1000 MW超临界机组,对常规低温省煤器烟气余热利用系统进行了热力学分析,发现该系统可使系统发电标准煤耗率降低2.50 g·(kW·h)~(-1),但分析发现,空气预热器耗散占输入媚的22.03%,多于锅炉排烟所携带的。为此,本文提出了集成SCO_2动力循环的火电厂低温烟气热能利用系统,旨在减少空气预热器中的耗散。对SCO_2动力循环参数进行了优化,在优化参数下该系统可以使发电标准煤耗率降低3.62 g.(kW·h)~(-1),进一步集成低温省煤器可使发电标准煤耗率降低达5.58 g·(.kW·h)~(-1),最后采用分析结果解释了系统节能的本质原因。     

固体氧化物燃料电池分布参数模拟研究

固体氧化物燃料电池(SOFC)是一种将储存在燃料和氧化剂中的化学能通过电化学反应的方式直接转换为电能和中高温热能的全固态发电装置,被认为是最接近商业化的先进清洁高效发电技术之一。为了考察SOFC在变负荷条件下的稳态和非稳态特性,在MATLAB模拟环境下,建立了板式SOFC的一维稳态和非稳态分布参数模型,该模型充分考虑了SOFC中传热传质、流体流动、化学与电化学反应等因素相互耦合的影响,模拟分析了SOFC在不同条件下的工作参数变化对系统性能的影响。     

褐煤烟气预干燥发电系统变工况特性的仿真研究——机组负荷与原煤水分的影响

本文建立了常规褐煤发电系统与褐煤烟气预干燥发电系统的全厂机炉耦合变工况仿真模型,以600 MW机组为例研究了机组负荷和原煤水分变化对褐煤烟气预干燥系统节能、节水效果的影响。仿真结果表明:褐煤烟气预干燥发电系统具有显著的节能优势和水回收能力。在THA工况下,原煤水分由39.5%降低至预干燥煤的9.82%,同时乏气废热用于预热空气至55℃,可使烟气预干燥发电系统的标准煤耗率比常规褐煤发电系统降低9.91 g·(kW·h)~(-1),同时可回收12.8t·h~(-1)煤中水分。机组负荷下降至50%THA时,节煤量下降至9.30 g·(kW·h)~(-1),水回收量下降至7.3 t·h~(-1)。原煤水分每下降10%,节煤量下降1.25 g·(kW·h)~(-1),同时水回收量下降3.8 t·h~(-1)。     

半导体激光自混合干涉类锯齿波成立条件

本文从激光系统稳态条件出发,建立了具有普遍意义的半导体激光自混合干涉系统模型,通过仿真分析,结果表明：在较强光反馈水平时,自混合干涉信号并非都是类锯齿波形。波形形状受光反馈水平及激光器线宽展宽因数的共同制约。本文结果对激光自混合干涉技术的应用具有重要的指导意义。     

基于遗传算法优化卷积长短记忆混合神经网络模型的光伏发电功率预测

光伏发电受天气与地理环境影响,呈现出波动性和随机多干扰性,其输出功率容易随着外界因素变化而变化,因此预测发电输出功率对于优化光伏发电并网运行和减少不确定性的影响至关重要.本文提出一种基于遗传算法(GA)优化的卷积长短记忆神经网络混合模型(GA-CNN-LSTM),首先利用CNN模块对数据的空间特征提取,再经过LSTM模块提取时间特征和附近隐藏状态向量,同时通过GA优化LSTM训练网络的超参数权重与偏置值.在初期对历史数据进行归一化处理,以及对所有特征作灰色关联度分析,提取重要特征降低数据计算复杂度,然后对本文提出来的经GA优化后的CNN-LSTM混合神经网络(GA-CNN-LSTM)算法模型进行光伏功率预测实验.同时与CNN,LSTM两个单一神经网络模型以及未经GA优化的CNNLSTM混合神经网络模型的预测性能进行比较.结果显示在平均绝对误差率(MAPE)指标下,本文提出的GA-CNN-LSTM算法模型比单一神经网络模型最好的结果减少了1.537%的误差,同时比未经优化的CNNLSTM混合神经网络算法模型减少了0.873%的误差.本文的算法模型对光伏发电功率具有更好的预测性能.     

混合工质变浓度空调系统的试验研究

本文在分析混合工质单位容积制冷量随组成浓度变化的特性的基础上,结合筛选出的工质R22/R142b和R32/R124,进行固定工况下变浓度稳态性能对比试验和变工况变浓度调节稳态性能试验,测得空调系统在不同浓度下的稳态性能参数,验证了混合工质变浓度的容量调节特性。     

直接式S-CO_2塔式太阳能热发电系统光-热-功一体化热力学分析

本文将简单回热,预压缩,再压缩,部分冷却和中间冷却超临界二氧化碳(S-CO_2)布雷顿循环分别与塔式太阳能热发电(SPT)系统结合,建立了直接式S-CO_2塔式太阳能热发电系统的光-热-功一体化模型,对5种S-CO_2循环下整个SPT系统在不同透平入口温度下的热力学性能进行了对比分析。结果表明:随着透平入口温度的增大,整个SPT系统的效率在650℃附近具有最大值,表明直接式S-CO_2塔式太阳能热发电系统的运行温度并非越高越好;在本文研究的透平入口温度范围内(500~800℃),中间冷却和部分冷却S-CO_2循环下的SPT系统具有最高的效率,但系统也最为复杂;再压缩S-CO_2循环下的SPT系统在高温范围(650~800℃)具有较高的效率,且系统比较简单,具有巨大的应用潜力。     

环境风下光伏-温差发电系统耦合特性分析

综合考虑环境风和冷却流体的耦合作用,建立了采用纳米流体冷却的光伏(PV)-温差发电(TE)系统的性能分析数学模型,探讨了聚光比、风速、冷却流体流速、负载和热电材料品质因数等对其性能的影响。结果表明:采用纳米流体为冷却介质提高了系统的总效率;系统最佳负载值不同于温差发电模块效率最大时的负载;风速对系统最大效率的影响随着热电材料品质因数的变化而变化。     

太阳能燃气轮机与卡林那循环联合的热发电系统

本文提出了一种带间冷回热的太阳能燃气轮机与卡林那循环组成的联合循环发电系统,对其热力性能进行了分析,并研究了关键运行参数对热力性能影响。塔式太阳能接收器将经过间冷压缩的压缩空气加热至1000℃用以驱动燃气轮机做功。卡林那循环用以回收燃气余热发电。基于蔡睿贤的比较法,推导出了该系统太阳能热发电效率的简明解析式。结果表明,当燃气轮机入口温度为1000℃时,该系统的(火用)效率和太阳能热发电效率分别可达到29%和27.5%,比太阳能燃气-蒸汽联合循环分别高1.8%和1.6%。该系统的提出,为提高太阳能热发电系统的太阳能热发电效率提供了一种方法,并且对太阳能热发电耗水大的问题提供了一个解决途径。     

基于热释电探测器DIGA数学模型

根据热释电探测器工作原理 ,对其使用特点进行了分析。在分光型红外气体分析器 (DIGA)设计原理基础上 ,建立了基于热释电探测器的红外气体分析系统输入输出数学模型。依据该模型研制了一个新型多组分红外气体分析器 ,并指出设计DIGA注意的若干问题。应用表明 ,该模型对DIGA的设计、研究、性能分析和进一步改进具有一定的参考价值     

静止水滴真空闪蒸模型及实验研究

本文建立了描述真空制取二元冰过程中静止水滴的传热传质模型,研究冰晶形成过程的结晶成核与生长现象及其影响因素。设计并建立了一种可视化的真空制冰系统,清晰地展示了静态水滴成核结冰时液态蒸发、伴随气泡生长的蒸发、稳态蒸发结冰、伴随气泡生长的结冰、外部结冰内部气泡逸出最终爆裂的五种形态;利用所设计的二元冰真空制备装置进行冰晶的生成实验研究,分析讨论各种因素对二元冰真空制备的影响,并通过实验对照比较来证明模型的可靠性。     

Bearings-Only Target Motion Analysis Using a Dual-Waveband Infrared System

Infrared systems are widely used for target detection, designation and tracking. For example, an Infrared Search and Track (IRST) system, as a typical airborne or shipboard detecting device, is widely equipped for the remote target detection and tracking. In recent years, the problem of target motion analysis (TMA) and tracking has been studied increasingly extensively. In an airborne infrared system, the problem becomes more difficult due to absence of range information. In this paper, the infrared model and motion model of typical aerial targets are described. An airborne dual-waveband IRST system, which is quite familiar nowadays, is choosed for implementation of target motion analysis. Based on the above, a novel and more practical algorithm of target tracking via bearings-only measurements is formed and the major parameters are defined according to a typical airborne dual-waveband IRST system. Finally, data simulation is implemented, and the results demonstrate the new algorithm has a better performance than before for bearings-only target tracking.     

太阳能-土壤源热泵优化运行研究

根据太阳能-土壤源热泵系统各部件之间的耦合关系,建立了各部件的仿真模型,并在此基础上建立了太阳能-土壤源热泵系统仿真模型,将其应用于实际工程进行模拟计算,分别对系统的两种运行模式进行了研究分析。     

Stability analysis of multiple-lattice self-anticipative density integration effect based on lattice hydrodynamic model in V2V environment

Under the environment of vehicle-to-vehicle (V2V) communication, the traffic information on a large scale can be obtained and used to coordinate the operation of road traffic system. In this paper, a new traffic lattice hydrodynamic model is proposed which considers the influence of multiple-lattice self-anticipative density integration on traffic flow in the V2V environment. Through theoretical analysis, the linear stability condition of the new model is derived and the stable condition can be enhanced when more-preceding-lattice self-anticipative density integration effect is taken into account. The property of the unstable traffic density wave in the unstable region is also studied according to the nonlinear analysis. It is shown that the unstable traffic density wave can be described by solving the modified Korteweg-de-Vries (mKdV) equation. Finally, the simulation results demonstrate the validity of the theoretical results. Both theoretical analysis and numerical simulations demonstrate that multiple-lattice self-anticipative density integration effect can enhance the stability of traffic flow system in the V2V environment.     

激光侦察装备综合作战效能评估模型

根据激光侦察装备的工作原理,分析了影响其作战效能的主要因素,用系统分析的方法,通过对系统的可用度向量A、可信度矩阵D和能力向量C的建模,建立了定量评价激光侦察装备综合作战效能的数学模型,并通过算例对模型进行了验证.     

滑动回归最小二乘算法在某电动振动台模型辨识中的应用

为了能够准确地建立电动振动台的仿真模型,了解电动振动台系统特性,笔者在分析电动振动台数学模型的基础上,利用先进的滑动回归最小二乘辨识算法,有效地开展了电动振动台这一复杂电力学系统阶数和时延的确认,参数估计,并最终建立了系统的ARMA模型。文章最后,举出了某型电动台空台面和另一型振动台带滑台的模型辨识结果,并通过正弦扫频试验给予验证。结果表明,该算法辨识精度高,收敛速度快,鲁棒性强,能克服一定的噪声,对于高阶线性系统辨识具有良好的辨识效果。     

Characteristic model of travelling wave ultrasonic motor

In general, the design and analysis of ultrasonic motor and motor’s control strategy are based on mathematical model. The academic model is widely used in the analysis of traveling wave ultrasonic motor (TWUSM). But the dispersive characteristic of piezoelectric ceramics and other complicated process, such as the friction, make the model’s precision not so accurate. On the other hand, identification modeling method, which is built based on the tested data, has obtained increasing application in the study of ultrasonic motor’s control technology. Based on the identification model, many control strategies can be designed easily. But the identification model is an approximate model, so if a more accurate model of ultrasonic motor can be obtained, the analysis and design of motor control system will be more effective. Characteristic model is a kind of identification model which can accurately describe the characteristics of TWUSM. Based on the tested data, this paper proposes the modeling method of ultrasonic motor’s characteristic model. The paper also makes a comparison of the effectiveness of different identification algorithms. Aiming at the speed control of ultrasonic motor, the influence of the parameter’s initial values on the precision of model is discussed. The calculating results indicate the availability of this characteristic model.     

Stability of weighted spectral distribution in a pseudo tree-like network model

The comparison of networks with different orders strongly depends on the stability analysis of graph features in evolving systems. In this paper, we rigorously investigate the stability of the weighted spectral distribution(i.e., a spectral graph feature) as the network order increases. First, we use deterministic scale-free networks generated by a pseudo treelike model to derive the precise formula of the spectral feature, and then analyze the stability of the spectral feature based on the precise formula. Except for the scale-free feature, the pseudo tree-like model exhibits the hierarchical and small-world structures of complex networks. The stability analysis is useful for the classification of networks with different orders and the similarity analysis of networks that may belong to the same evolving system.