A comprehensive review of solar thermoelectric cooling systems

The negative environmental impacts of burning fossil fuels have forced the energy research community seriously to consider renewable sources, such as naturally available solar energy. This paper provides an overview of solar thermoelectric (TE) cooling systems. Thus, this review presents the details referring to TE cooling parameters and formulations of the performance indicators and focuses on the development of TE cooling systems in recent decade with particular attention on advances in materials and modeling and design approaches. Additionally, the TE cooling applications have been also reviewed in aspects of electronic cooling, domestic refrigeration, air conditioning, and power generation. Finally, the possibility of solar TE cooling technologies application in “nearly zero” energy buildings is briefly discussed, and some future research directions are included. This research shows that TE cooling systems have advantages over conventional cooling devices, including compact in size, light in weight, high reliability, no mechanical moving parts, no working fluid, being powered by direct current, and easily switching between cooling and heating modes.     

Influence of processing on stability,microstructure and thermoelectric properties of Ca3Co4 − xO9 + δ

Due to high figure of merit, Ca₃Co_4 ? xO_9 + δ (CCO) has potential as p-type material for high-temperature thermoelectrics. Here, the influence of processing including solid state sintering, spark plasma sintering and post-calcination on stability, microstructure and thermoelectric properties is reported. By a new post-calcination approach, single-phase materials were obtained from precursors to final dense ceramics in one step. The highest zT of 0.11 was recorded at 800 °C for CCO with 98 and 72% relative densities. In situ high-temperature X-ray diffraction in air and oxygen revealed a higher stability of CCO in oxygen (～970 °C) than in air (～930 °C), with formation of Ca₃Co₂O₆ which also showed high stability in oxygen, even at 1125 °C. Since achievement of phase pure high density CCO by post-calcination method in air is challenging, the phase stability of CCO in oxygen is important for understanding and further improvement of the method.     

Novel poly(aryl ether nitrile ketone) foams and the influence of copolymer structure on the foaming result

Novel poly(aryl ether nitrile ketone) foams were prepared through the batch foaming method with supercritical CO₂ as the blowing agent. Both temperature‐induced and pressure‐induced foaming methods were conducted to examine the influence of nitrile groups on the foaming result. The results indicated that nitrile groups influenced the foaming result by affecting both the viscoelasticity and CO₂ absorption of the polymers. In addition, the CO₂ solubility of the polymers increased with increasing CN content presumably because of the Lewis acid–base nature of the interaction between the CO₂ molecules and the nitrile groups. The cell growth process was assessed by analyzing the influence of foaming temperature and foaming time on the cell morphology. Nanocellular foams with a minimum size of 30–50 nm were achieved by the temperature‐induced foaming method. Moreover, highly expanded foams with a maximum expansion ratio of 23.6 were obtained by the pressure‐induced foaming method. © 2018 Society of Chemical Industry     

抗凝冰乳化沥青涂层的性能研究

为了研究自制融雪剂对抗凝冰乳化沥青涂层性能的影响,将自制固态型融雪剂按5%、10%、15%的比例加入乳化沥青制备涂层乳液,采用水煮法、摆式摩擦仪、电导率试验分别对涂层材料的粘附性、抗滑性能和抗凝冰性能进行了测试。结果表明:自制型融雪剂对乳化沥青与集料的粘附性影响不大;随着融雪剂掺配比例的增大,抗凝冰乳化沥青涂层的摩擦系数有所降低,但均满足规范要求;相比于普通沥青涂层,抗凝冰乳化沥青涂层的抗凝冰性能得到改善,且随着融雪剂掺配比例的增大,凝冰性能逐渐提高。     

超高效液相色谱串联质谱法测定烟草中的噁霉灵残留

为降低烟草中噁霉灵检测中的基质干扰，提高检测灵敏度和和稳定性，通过试验建立了以QuEChERS为样品前处理方法、液相色谱串联质谱仪为检测仪器的烟草中噁霉灵残留检测方法。样品加水浸润后，经丙酮提取、盐析试剂包除水、石墨化炭黑除杂后，采用Agilent ZORBAX 300SB-C8液相色谱柱（2.1 mm×100 mm，1.8 μm）分离，甲醇-水程序洗脱，ESI雾化，串联质谱MRM检测。结果发现，该方法在0.0025~0.0500 mg/L范围内线性良好，决定系数r²=0.9996，定量检测限1.06 μg/L，回收率在90.8%~92.0%之间，相对标准偏差为5.1%。运用该方法测定烟草中的噁霉灵，操作简单，检测精度高，满足CORESTA对烟草农残检测的要求。     

Leading edge erosion of wind turbines: Effect of solid airborne particles and rain on operational wind farms

Leading edge erosion (LEE) affects almost all wind turbines, reducing their annual energy production and lifetime profitability. This study presents results of an investigation into 18 operational wind farms to assess the validity of the current literature consensus surrounding LEE. Much of the historical research focuses on rain erosion, implying that this is the predominant causal factor. However, this study showed that the impact of excessive airborne particles from seawater aerosols or from adverse local environments such as nearby quarries greatly increases the levels of LEE. Current testing of leading edge protection coatings or tapes is based on a rain erosion resistivity test, which does little to prove its ability to withstand solid particle erosion and may drive coating design in the wrong direction. Furthermore, it was shown that there is little correlation between test results and actual field performance. A method of monitoring the expected level of erosion on an operational wind turbine due to rain erosion is also presented. Finally, the energy losses associated with LEE on an operational wind farm are examined, with the average annual energy production dropping by 1.8% due to medium levels of erosion, with the worst affected turbine experiencing losses of 4.9%.     

基于粒子群算法的车辆半主动悬架模糊PID控制的优化研究

为 了 改 善 轮 毂 驱 动 电 动 汽 车 非 簧 载 质 量 增 加 导 致 行 驶 平 顺 性 和 操 纵 稳 定 性 下 降 的 问 题 ，提 出了 一 种 基 于 粒 子 群 算 法 优 化 的 模 糊ＰＩＤ控 制 器 。 首 先 ，建 立 １ ／ ２ 车 辆 半 主 动 悬 架 模 型 ，完 成 对 模 糊 控 制 器的 设 置 ，并 在Ｓｉｍ ｕｌｉｎｋ 环 境 下 建 立 带 有 模 糊 ＰＩＤ控 制 器 的 悬 架 模 型 ，然 后 使 用 粒 子 群 算 法 对 模 糊ＰＩＤ控 制器 进 行 优 化 。 最 后 ，对 粒 子 群 算 法 优 化 的 模 糊ＰＩＤ控 制 半 主 动 悬 架 进 行 仿 真 研 究 。 仿 真 结 果 表 明 ，粒 子 群算 法 优 化 的 模 糊ＰＩＤ控 制 的 悬 架 系 统 相 较 于 传 统ＰＩＤ控 制 和 模 糊ＰＩＤ控 制 ，悬 架 性 能 得 到 大 幅 提 升 。     

两种多层穿梭车系统的性能比较分析

物流配送中心订单响应速度的加快,对订单拣选系统提出了更高的要求。多层穿梭车系统因其柔性强、效率高等特点,近年来得到了广泛应用。多层穿梭车系统具有两种形式--基于转载车和基于环形输送线,二者均可实现货物的快速拣选,但在系统吞吐量和订单完成周期方面存在差异,致使企业决策者难以进行系统选择。基于上述原因,本文比较两种多层穿梭车系统的性能差异。建立两个系统的开环排队网络模型,然后求解系统吞吐量、订单完成周期,通过仿真验证了排队论模型的准确性,通过试验对两种系统的性能进行对比分析。结果表明,系统吞吐量与层数、巷道数相关,层数越多,巷道数越少,转载车系统相对于环线系统优势越显著;订单完成周期与层数、订单到达率相关,层数越多,订单到达率越低,转载车系统相对于环线系统越具优势。     

蓝宝石晶体掏棒机内冷式刀柄辅具结构研究

因蓝宝石晶体硬度为莫氏9级,仅次于最硬白金刚石,蓝宝石晶体掏棒加工中会产生很高的切削热量,筒刀和晶体必须进行筒刀内部和外部同时强力冷却,才能保证掏棒加工的稳定性和晶棒质量。所以蓝宝石晶体掏棒加工中要解决的关键技术问题之一,是内冷式刀柄辅具结构的研究、设计、试制、改进和联机使用。     

运行压力对超声雾化溶液除湿系统性能的影响

基于溶液除湿热质传递过程中所遵循的质量平衡、能量平衡模型，以超声雾化溶液除湿系统（UADS）为例，探讨了在不同空气处理温度、湿度下，系统运行压力对除湿性能的影响。结果表明：随着运行压力的升高，UADS系统的除湿性能显著改善。特别是在所处理空气入口温度较高时，提升系统运行压力对除湿效率的提高作用更加显著。同时，当所处理空气的含湿量较大时，提高运行压力对系统除湿速率的增幅明显，而对除湿效率的改善作用减弱。此外，当除湿系统在较高压力下运行时，其除湿效率受所处理空气入口温湿度变化而产生的波动减小，系统性能稳定性显著改善。所得结果可对溶液除湿系统的高效、稳定运行提供积极参考。