西北地区膨润土湿化变形特征的试验研究(英文)

通过对西北地区原生与重塑膨润土的湿化试验,研究了初始含水量、初始干密度与荷载水平对湿化变形的影响。研究表明,当初始干密度给定时,湿化变形增量随初始含水量增加而减小;当初始含水量给定时,湿化变形增量随初始干密度增加而增大。重塑膨润土也同样有此规律,但重塑膨润土的湿化变形比原生膨润土为大。     

Development of an advanced MEA to use high-concentration methanol fuel in a direct methanol fuel cell system

Despite serious methanol crossover issues in Direct Methanol Fuel Cells (DMFCs), the use of high-concentration methanol fuel is highly demanded to improve the energy density of passive fuel DMFC systems for portable applications. In this paper, the effects of a hydrophobic anode micro-porous layer (MPL) and cathode air humidification are experimentally studied as a function of the methanol-feed concentration. It is found in polarization tests that the anode MPL dramatically influences cell performance, positively under high-concentration methanol-feed but negatively under low-concentration methanol-feed, which indicates that methanol transport in the anode is considerably altered by the presence of the anode MPL. In addition, the experimental data show that cathode air humidification has a beneficial effect on cell performance due to the enhanced backflow of water from the cathode to the anode and the subsequent dilution of the methanol concentration in the anode catalyst layer. Using an advanced membrane electrode assembly (MEA) with the anode MPL and cathode air humidification, we report that the maximum power density of 78 mW/cm² is achieved at a methanol-feed concentration of 8 M and cell operating temperature of 60 °C. This paper illustrates that the anode MPL and cathode air humidification are key factors to successfully operate a DMFC with high-concentration methanol fuel.     

多联机系统的新风处理及其节能方式

全面论述了多联机系统中各种新风处理方式的特点,节能要求重点对新风换气机用于多联机系统进行了分析,指出新风换气机应用于多联机系统是一种较为理想的新风供应方式,并对新风换气机此种新风供应方式的冬季加湿问题进行了探讨。     

机房新风系统节能技术

通过和传统的机房新风系统作比较,介绍采用新风混风技术、变频调速技术、湿膜加湿技术等的新型新风处理方式,以及在全年不同时间中的新风运行模式,说明这种新风方式的节能效果.     

小流量涡流管热端加湿制冷系统实验研究

针对一种小流量涡流管加湿制冷系统进行了实验研究，得出了涡流管制冷系统不同入口压力下无加湿系统和有加湿系统的绝热效率曲线，指出也需要解决的关键技术问题。实验表明，有加湿系统可以大大提高涡流管的绝热效率。     

Ferritic Cathodes Degradation by Potassium/Chromium Poisoning and Air Humidification

Degradation mechanisms inherent to ferritic LSF‐SDC and LSCF‐GDC cathodes are studied by post‐mortem analysis of cells which suffered the most significant performance deterioration in a set of 18 500 h tests carried out under a specific experimental design. Three cathode processing parameters (composition, thickness, and sintering temperature) were combined with five operation conditions (chromium presence, current density, operating temperature, air flow, and humidification) through this design of experiments based in a L₁₈ Taguchi matrix. In the case of cells exposed to chromium vapors from Crofer 22 APU pieces, those cells which exhibited K₂Cr₂O₇ deposition in the cathode/GDC barrier interface underwent the most aggressive ASR degradation. Similar deposits were also observed on the surface of LSC current collectors. Two cells exposed to highly humidified air (20%) exhibited cathode delamination and GDC barrier deterioration by crack propagation though no foreign elements diffusion to the interface could be detected.     

改善PVC树脂流动性的措施

介绍了蒸汽加湿、添加抗静电剂、纯水雾化加湿等措施对PVC树脂流动性的改进效果,认为纯水雾化加湿能够很好地消除PVC树脂颗粒在长距离气流输送过程中产生的静电,能有效改善树脂颗粒的流动性,提高树脂的加工性能。     

载气增湿蒸发技术处理切削废液的研究

利用空气作为载气,采用蒸发塔进行了载气增湿蒸发浓缩切削废液的实验,探究了操作条件对蒸发过程的影响。随着载气流量的增加,容积传质系数、蒸发量和整塔压降均增大,出口载气VOC浓度减小;随着载气温度、循环流量的增加,容积传质系数、蒸发量、整塔压降和出口载气VOC浓度均增大。实验条件下容积传质系数及蒸发量最大达到了13.95 g·（m³·s）^-1和3.39 kg·h^-1;出口载气VOC浓度最大为6.2 mg·L^-1,小于《大气污染物综合排放标准》中规定值。研究结果表明载气增湿蒸发工艺能有效浓缩切削废液,为工业化应用奠定了基础。     

Sensitivity analysis of a polybenzimidazole‐based polymer fuel cell and insight into the effect of humidification

The present work describes a systematic investigation of the effect of operating temperature, cathode stoichiometry, anode stoichiometry and reactants humidification rate on the behavior of a polybenzimidazole‐based high temperature polymer fuel cell. The effect of reactants humidification was also considered; actually, in real applications, the syngas holds great amounts of water. Furthermore, water diffuses through the membrane and reaches the cathode side where it adds to the water produced by the electrochemical reaction. The investigation is based on the analysis of polarization curves measured under different operating conditions. Anode stoichiometry has no impact on the fuel cell voltage, while cathode stoichiometry and fuel cell temperature are relevant. When the anode stream is humidified, negligible effects take place; conversely, when the cathode stream is humidified, a consistent drop in the fuel cell voltage is observed, with a consequent drop in the power output. When air is saturated at 70 °C, a power loss of 8% and 27% takes place at 0.55 A cm^?2 and 0.9 A cm^?2, respectively. Such a finding might represent an issue when high power densities are pursued. The effect of cathode humidification was further investigated by means of electrochemical impedance spectroscopy and cyclic voltammetry. Thanks to dedicated tests, the effect of water in the cathode feed stream was clarified. Cathode humidification increases the electrode catalyst active area due to the dilution of the phosphoric acid retained in the electrode. Conversely, the presence of water hinders the oxygen mass transport to the catalyst active sites. Copyright © 2013 John Wiley & Sons, Ltd.     

气调冷库加湿分析与软件算法

气调冷库内的果蔬在被冷却的同时,由于自身呼吸热和干冷空气的吸湿作用会不断失去自身水分,这不但会加速自身营养成分的流失和破坏,而且会减少自身的质量,造成较大的经济损失。因此,对气调冷库内的果蔬及时、准确地加湿是一项非常重要的技术工作。本文分析阐述减湿和加湿的原理及过程,并提出修正的湿空气物性参数模型方程,依据牛顿迭代算法,开发冷库果蔬加湿计算机辅助计算软件,其计算结果与现有冷库工作过程的实测数据相吻合。