Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough receiver

This paper proposes a comprehensive thermodynamic and economic model to predict and compare the performance of concentrated solar power plants with traditional and novel receivers with different configurations involving operating temperatures and locations. The simulation results reveal that power plants with novel receivers exhibit a superior thermodynamic and economic performance compared with traditional receivers. The annual electricity productions of power plants with novel receivers in Phoenix, Sevilla, and Tuotuohe are 8.5%, 10.5%, and 14.4% higher than those with traditional receivers at the outlet temperature of 550°C. The levelized cost of electricity of power plants with double-selective-coated receivers can be decreased by 6.9%, 8.5%, and 11.6%. In Phoenix, the optimal operating temperature of the power plants is improved from 500°C to 560°C by employing a novel receiver. Furthermore, the sensitivity analysis of the receiver heat loss, solar absorption, and freeze protection temperature is also conducted to analyze the general rule of influence of the receiver performance on power plants performance. Solar absorption has a positive contribution to annual electricity productions, whereas heat loss and freeze protection temperature have a negative effect on electricity outputs. The results indicate that the novel receiver coupled with low melting temperature molten salt is the best configuration for improving the overall performance of the power plants.     

A spectrally selective surface structure for combined photothermic conversion and radiative sky cooling

The sun and outer space are the ultimate heat and cold sources for the earth, respectively. They have significant potential for renewable energy harvesting. In this paper, a spectrally selective surface structure that has a planar polydimethylsiloxane layer covering a solar absorber is conceptually proposed and optically designed for the combination of photothermic conversion (PT) and nighttime radiative sky cooling (RC). An optical simulation is conducted whose result shows that the designed surface structure (i.e., PT-RC surface structure) has a strong solar absorption coefficient of 0.92 and simultaneously emits as a mid-infrared spectral-selective emitter with an average emissivity of 0.84 within the atmospheric window. A thermal analysis prediction reveals that the designed PT-RC surface structure can be heated to 79.1°C higher than the ambient temperature in the daytime and passively cooled below the ambient temperature of approximately 10°C in the nighttime, indicating that the designed PT-RC surface structure has the potential for integrated PT conversion and nighttime RC utilization.     

模糊控制的模糊推理分析

分析了使用RZ算子时推理合成规则(CRI)不具有还原性和不能正确进行模糊推理的原因,给出了正确应用CRI的条件;分析了全蕴涵3I算法的不足及其具有还原性的原因;对各种蕴涵算子的模糊推理进行分析比较,得到了正确的推理算法;对模糊推理在理论和实际应用中的矛盾作了具体说明.     

高压条件下石英砂中的静力触探试验及大变形模拟

在深部土层中进行原位试验时,以往针对中低应力水平的数据解译公式不再适用。为探究砂土在高应力条件下的力学特性,利用自行研制的高压标定罐,改变围压水平,进行不同密实度石英砂中的静力触探试验,基于任意拉格朗日—欧拉格式的大变形有限元方法,模拟静力触探仪的完整贯入过程,有效避免了锥尖周围的网格扭曲。大变形模拟中采用修正摩尔—库伦模型描述砂土的内摩擦角和剪胀角随累积塑性剪应变的变化,并通过修正弯曲元试验,确定合理的土体剪切模量。标定罐试验和大变形有限元方法获得的锥尖阻力结果能很好地相互验证;在此基础上,建立高应力条件下静力触探锥尖阻力与砂土相对密实度之间的关系,与已有的低应力水平试验结果进行对比,证明建立的经验公式能通过锥尖阻力很好地预测砂土的相对密实度。     

智慧能源区块链平台及典型应用分析与设计

针对智慧能源开放、动态和可控难度大等特点,为了实现开放、自主、灵活的能源消费方式,本文利用区块链去中心化的全新分布式基础架构与计算方式等特点,采用区块链技术支持智慧能源领域新的应用模式。本文分析了区块链的基本原理、技术特征和关键技术,基于智慧能源与传统能源的对比分析结果,提出了智慧能源区块链平台并设计了平台架构。随后,本文对平台技术选型进行了分析,提出并设计了平台技术架构和平台接口。最后,本文基于智慧能源区块链平台,提出了社区能源共享及绿证发行管理两类智慧能源典型应用,设计了两个典型应用的数据结构和功能函数。基于本文的分析与设计可以看出,区块链技术在智慧能源领域和未来能源革命中必将发挥重要作用。智慧能源区块链平台的相关理念和技术特征符合未来能源互联网的发展趋势,基于该平台可培育、衍生出众多的基于区块链的智慧能源应用。     

镀锌层硅酸盐+虫胶复合转化膜的制备和表征

目的阻碍热镀锌板出现白锈,提高镀锌层的耐腐蚀性能。方法采用正交试验法优化出添加虫胶水溶液的有机无机复合钝化液。通过电化学Tafel极化曲线、交流阻抗(EIS)、乙酸铅点滴和中性盐雾试验,对比分析基体、硅酸盐+虫胶复合钝化膜与铬酸盐钝化膜的耐腐蚀性能。采用摩擦法测试对比分析基体和无铬钝化膜试样的附着性能,并通过扫描电子显微镜、X射线光电子能谱和红外光谱对形貌和结构进行分析。结果添加虫胶水溶液的复合钝化膜表面平整致密,72 h中性盐雾试验后的腐蚀面积小于10%。乙酸铅点滴试验和电化学测试显示,复合钝化膜的耐腐蚀性能较基体好。附着力试验测试显示,复合钝化膜具有良好的附着能力。结论因为复合钝化液中的虫胶与硅酸盐交织为O—Si—CH_2结构,与金属离子结合生成致密的膜层附着在镀锌层表面,使得复合钝化膜致密平整,且使腐蚀过程得到了强烈的抑制。     

喷丸处理对GH3535合金900℃恒温氧化行为的影响

采用不连续增重法,对喷丸状态与非喷丸状态GH3535合金900℃恒温氧化行为进行了对比研究。结果表明,900℃下,喷丸强度0.45Nmm样品与未喷丸样品相比,氧化增重降低了79.7%。未喷丸GH3535合金表面氧化产物为NiCr2O4,MoO2,NiMoO4,喷丸状态下氧化膜主要由NiO、NiFe2O4、Cr2O3和NiCr2O4组成。喷丸处理后GH3535合金表面产生塑性变形使晶粒细化,位错密度增加,在合金表层塑性变形区域的位错及晶界充当了Cr原子的快速扩散路径,增加了Cr原子扩散通量,促进Cr向表面扩散形成富Cr氧化物,使得Cr2O3层的更快形成,减少了瞬态氧化期。     

电子行业用高纯钯的制备研究

高纯钯在电子行业等领域应用广泛,需求迫切。以氯化钯为原料,提出采用氯化铵沉淀-氨水配合联合工艺净化钯溶液,水合肼还原纯净钯溶液制备高纯钯。结果表明,固体氯化钯溶解后,在合适的条件下,该钯溶液经过氧化-氯化铵沉淀、氨水配合有效去除杂质元素,获得纯净二氯四氨合钯溶液,再经水合肼还原后,获得纯度99.999%高纯钯,其碳、氧、氮等杂质元素总含量小于355×10^-6。     

改进RetinaNet的水泥路面露骨病害检测

露骨病害是水泥路面常见的病害之一,会严重影响路面使用年限和行车安全性能.因此,及时对露骨病害进行检测与修复十分重要.针对传统的人工检测方法检测精度不高且检测效率低的问题,本文提出一种基于改进RetinaNet模型的水泥路面露骨病害检测方法.首先对人工和检测车采集露骨病害图像进行滤波、去噪等预处理操作,构建模型训练数据集...     

基于AutoCAD的弧段地质剖面精确绘制算法与实现

当地质平面图中的剖面线包含弧段时,传统的基于AutoCAD开发的绘图工具绘制出的地质剖面图总是比实际剖面长度短一点。为解决这一问题,利用弧长公式、AutoCAD二次开发技术、出图标准,研究并实现了带弧段地质剖面图的精确绘制,并结合工程地质数据库,自动在剖面图上绘制勘察信息。应用效果表明:绘制出的弧段剖面图长度、地形高程、地质界线特征、相交剖面特征以及勘察点位置与平面图完全吻合,图上自动绘制的勘察信息与工程地质数据库数据一致。该技术提高了制图效率,提升了工作质量,可在多个平台的弧段地质剖面图绘制中推广。