变海水温度下舰用汽轮机组的环境适应性分析

鉴于舰用主汽轮机组的工作特性,指出了舰用主汽轮机组装置特有的环境适应性概念与度量的特殊性,以舰用主汽轮机组的耗汽率、功率、安全性、航速等性能为评价指标,基于MATLAB/Simulink模型,探讨在海水温度变化情况下,舰用主汽轮机组的环境适应性。该研究成果对制定合理的战术具有重要的指导意义。     

海水环境下镍铁渣粉水泥土的抗渗性能

为研究镍铁渣粉对水泥土渗透性能的影响,采用加压型渗透装置对镍铁渣粉水泥土在清水环境和海水环境下进行渗透试验,并用压汞试验和扫描电镜-能谱分析试验对镍铁渣粉水泥土进行微观分析.结果表明：清水环境和海水环境下镍铁渣粉的掺入均能提升水泥土的抗渗性能,而海水环境下尤为明显;镍铁渣粉掺量超过20%后,镍铁渣粉掺量增加对水泥土抗渗性能的影响逐渐变小;镍铁渣粉能发挥微集料效应和活性效应,减小水泥土的最可几孔径和总孔隙率,增强其抗海水侵蚀性能;镍铁渣粉能使水泥土的微细观结构更加致密,同时能促进水泥土生成具有低钙硅比的水化产物,增强其抗渗性能.     

膜法海水提溴用PVDF中空纤维膜的研制

采用相转化法制备海水提溴用疏水性聚偏氟乙烯中空纤维膜,考察聚合物浓度、无机复合添加剂浓度、膜干燥方式及后处理方法对膜结构和性能的影响.结果表明,无机复合添加剂能有效提高膜机械性能,同时不影响膜疏水性;溶剂置换法不能完全避免膜收缩,从而直接影响膜孔结构和透气性能.物理后处理方法可显著提高膜透气性能,氮气通量为8.62 m3/(m2.h),孔隙率为63.31%,膜断裂强度可达到1.64 cN/Tex,膜断裂伸长率为79.10%.     

Corrosion behaviour of hot dip zinc and zinc-aluminium coatings on steel in seawater

A comparative investigation of hot dip Zn-25Al alloy, Zn-55Al-Si and Zn coatings on steel was performed with attention to their corrosion performance in seawater. The results of 2-year exposure testing of these at Zhoushan test site are reported here. In tidal and immersion environments, Zn-25Al alloy coating is several times more durable than zinc coating of double thickness. At long exposure times, corrosion rate for the Zn-25Al alloy coating remains indistinguishable from that for the Zn-55Al-Si coating of similar thickness in tidal zone, and is two to three times lower than the latter in immersion zone. The decrease in tensile strength suggested that galvanized and Zn-55Al-Si coated steel suffer intense pitting corrosion in immersion zone. The electrochemical tests showed that all these coatings provide cathodic protection to the substrate metal; the galvanic potentials are equal to −1,050, −1,025 and −880 mV (SCE) for zinc, Zn-25Al alloy and Zn-55Al-Si coating, respectively, which are adequate to keep the steel inside the immunity region. It is believed that the superior performance of the Zn-25Al alloy coating is due to its optimal combination of the uniform corrosion resistance and pitting corrosion resistance. The inferior corrosion performance by comparison of the Zn coating mainly results from its larger dissolution rate, while the failure of the Zn-55Al-Si coating is probably related to its higher susceptibility to pitting corrosion in seawater.     

采用纳滤预处理的海水淡化集成技术

海水淡化是解决淡水危机的主要方法之一，但由于海水的硬度、浊度和总固溶物含量均非常高，因而导致淡化水的能耗量和成本较高．采用纳滤膜技术可以降低海水的硬度和总固溶物及有机物的含量，减少结垢与污染，提高水回收率，有望实现海水淡化成本的进一步降低．详细介绍了纳滤与常规蒸馏法、膜法海水淡化相结合而构成的新型纳滤预处理海水淡化集成技术：NF—MSF、NF—SWRO、NF—SWROrej-MSF等的国外研究与应用进展情况．     

反渗透海水淡化技术最新研究动态

从降低海水反渗透淡化产水成本和环境友好过程的开发两个方面探讨了国内外海水反渗透淡化技术的最新研究成果和应用情况，包括能量回收器的研究、新型工艺过程的设计、海水反渗透膜的研究和应用、用膜法预处理代替传统化学器预处理以及NF—SWRO—MSF过程集成5个部分．     

Sandwich Photothermal Membrane with Confined Hierarchical Carbon Cells Enabling High‐Efficiency Solar Steam Generation

Solar‐driven vaporization is a sustainable solution to water and energy scarcity. However, most of the present evaporators are still suffering from inefficient utilization of converted thermal energy. Herein, a universal sandwich membrane strategy is demonstrated by confining the hierarchical porous carbon cells in two energy barriers to obtain a high‐efficiency evaporator with a rapid water evaporation rate of 1.87 kg m^?2 h^?1 under 1 sun illumination, which is among the highest performance for carbon‐based and wood‐based evaporators. The significantly enhanced evaporation rate is mainly attributed to the inherently optimized porous evaporation mode derived from the hierarchical hollow structures of pollen carbon cells, and the synergistically regulated water transporting and thermal management performance of the sandwich membrane. Moreover, the constructed sandwich membrane also exhibits excellent self‐regenerating performance in simulated seawater and high salinity water. The developed device can maintain an average evaporation rate of 4.3 L m^?2 day^?1 in a 25 day consecutive outdoor test.     

醋酸纤维素类渗透功能膜的研究进展

随着膜法水处理技术的迅猛发展,对渗透功能膜制备及应用技术的要求日益提高。与常规渗透膜制备所采用的主流膜材料聚酰胺相比,醋酸纤维素(CA)及其衍生物由于兼具无可比拟的资源优势和独特的耐氧化性等优势而备受关注。围绕醋酸纤维素类渗透膜在纳滤、反渗透和正渗透等领域的应用,简要介绍了该类膜材料的制备方法和改性方法,回顾了其在海水淡化、油水分离、重金属脱除、手性分离等领域的应用进展,并在分析醋酸纤维素类渗透膜产品在应用领域的技术和性能优势的基础上,指出了醋酸纤维素类渗透膜进一步发展需要重点关注的研究方向。     

氧化锌超疏水薄膜的制备及其耐久性

为了提高氧化锌(ZnO)纳米疏水膜层在实际应用中的耐久性能,采用水热法在铝基底表面制备出微纳米结构的ZnO超疏水薄膜,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和接触角测量仪对所得ZnO薄膜的成分、微观结构及润湿性能进行分析;利用UMT摩擦磨损试验机对薄膜的摩擦性能和机械疏水耐久度进行研究;并用CHI660E电化学工作站对超疏水试样在海水中的耐腐蚀性能进行测量分析。结果表明:制备的微纳米结构ZnO薄膜具有超疏水性,在未经低表面能物质改性的情况下,对水的静态接触角高达152°,滚动角仅为2°;摩擦磨损测试表明该薄膜在经过2 400磨损周期后仍能保持较高的静态接触角;电化学阻抗谱和Tafel曲线测试表明,该薄膜的确降低了铝在海水中的腐蚀速率,缓蚀率高达93.8%。     

超滤用于海水淡化预处理的研究进展

良好的预处理是保证反渗透(RO)装置长期稳定运行的关键要素之一.与传统预处理技术相比,UF预处理能够有效降低海水的SDI、浊度和TOC等,为RO装置提供优良、稳定的进水,增强RO膜的可靠性.详细评述了近年来国内外采用UF技术作为RO淡化预处理过程的研究和应用进展.此外,对UF膜的污染和控制对策研究进展也作了评述.UF作为膜法海水预处理技术已成为该领域的发展趋势.