Tilted wick solar still with external flat plate reflector: Optimum inclination of still and reflector

We present a theoretical analysis of a tilted wick solar still with an external flat plate reflector. The reflector is assumed to be able to be inclined forwards or backwards according to the seasons. We theoretically predicted the daily amount of distillate of the still throughout the year, which varies with the inclination angle of both the still and reflector. We found the optimum inclination angle of the still as well as the optimum inclination angle of the reflector for each month at 30°N latitude. The daily amount of distillate of the still can be increased by adjusting the inclination of both the still and reflector for any season, thus producing an average of about 21% more than a conventional tilted wick still throughout the year.     

海水淡化泵用2507超级双相不锈钢铸件的焊接修复工艺

使用2507超级双相不锈钢铸造海水淡化泵的承压铸件,通过焊条电弧焊对铸件出现的缺陷进行焊接修复。确定海水淡化泵用2507超级双相不锈钢铸件的合理焊接修复工艺参数,用于指导海水淡化泵用2507超级双相不锈钢铸件的生产。结果表明,采用E2594-16焊条,热输入控制在1 800 J/cm以下,层间温度控制在≤100 ℃,焊后经过1 080 ℃固溶处理可以得到较优的修复质量。     

国产万吨级低温多效海水淡化技术应用

介绍了神华河北国华沧东发电有限责任公司国产万吨级低温多效海水淡化装置的工艺流程、工作原理、技术特点,研究了海水淡化装置对天然海水温度、加热蒸汽压力等外部参数变化的适应性,分析了影响淡化装置制水经济性的因素,并讨论了淡化装置的负荷调节特性.试验结果表明,本套国产化装置运行稳定,制水负荷可在40%～110%之间灵活调节,产品水水质优良,达到了生活饮用水卫生标准.     

海岛一体化制水装置研究与应用示范

2009年10月,在洞头县大瞿岛村建成一套50m~3·d~(-1),海岛一体化制水装置,该装置采用先进的反渗透技术、能量回收技术、微电解技术,电抑菌技术,产水水质好,能耗省,制水成本低,占地面积少.本装置的应用示范打破了国外公司对海水淡化能量回收装置的垄断,对海岛地区降低海水淡化工程建设成本、降低制水能耗、提高产品水的水质以及降低设备运行维护费用等方面起到较好的示范推广作用,对缓解我国的海岛及部分沿海地区村庄的水资源危机和保障我国海水淡化的供水安全具有极为重大的意义.     

反渗透膜技术研究和应用进展

反渗透膜技术是20世纪60年代兴起的一门新型分离技术,是目前最为先进的分离技术之一,应用广泛。反渗透是渗透的逆过程,它是以压力差为推动力的膜分离过程。简单介绍了反渗透膜技术产生的背景和发展概况,着重论述了国内外反渗透膜技术的研究现状,介绍了反渗透膜在海水和苦咸水淡化、纯水制备以及医药和化工废水处理等方面的应用,并进一步探讨了反渗透膜技术目前存在的问题和未来发展趋势。     

基于温差函数的低温多效蒸发海水淡化过程热力学分析

从分析低温多效蒸发海水淡化过程的不可逆性出发,建立了海水加热和蒸发以及冷凝器海水预热过程的火用损失关系;导出了反映低温多效蒸发过程热力学效率的不可逆温差函数,为分析、评价过程的热力学效率提供了新的工具;并在温差函数的基础上研究讨论了蒸发器总效数、冷凝器端差、首效加热蒸汽温度和相对热容率等关键因素对低温多效蒸发海水淡化过程热力学效率的影响,为过程的优化、提高过程的能量利用率指明了方向。     

正渗透-水纯化和脱盐的新途径

正渗透作为一种潜在的水纯化和淡化新技术,国际上正对其进行着多角度、深层次的理论研究和实践探索.本文综述了正渗透的原理、当前的发展水平及其现存问题,旨在引起我国相关领域科研人员对它的重视.     

Progresses in improving the effectiveness of the single basin passive solar still

Single basin solar still is a very simple solar device used for converting available brackish or waste water into potable water. This device can be fabricated easily with locally available materials. The maintenance is also cheap and no skilled labor is required. This device can be a suitable solution to solve drinking water problem. Because of its low productivity it is not popularly used. Numbers of works are undertaken to improve the productivity of the still. In this work progresses in the works done on single basin passive types still to improve its productivity are reviewed. The orientation and inclination are optimized to receive maximum radiation and lower the condensation loss. Different materials are used in the basin along with water to improve the heat capacity, radiation absorption capacity and enhance the evaporation rate. Rubber is the best basin material to improve absorption, storage and evaporation effects. The effect of varying the depth of the basin water is also studied.     

Myth and reality of the hybrid desalination process

The paper discusses some misconceptions that have contributed to the continued use of thermal desalination processes and promotion of the hybrid desalination process for new plants being built or considered at Middle East locations. The misconceptions are examined both on the basis of fundamental thermodynamic principles and in terms of practical engineering parameters. The analysis shows that there is no economic or performance advantage in the installation of greenfield hybrid power/thermal desalination/ seawater reverse osmosis (SWRO) plants in preference to power/SWRO plants, because the latter would produce water more cheaply under all conditions and at all fuel costs, and would provide more operational flexibility than the former. The paper identifies situations where the hybrid desalination process can be fully justified: in existing power/desalination plants, where aging boilers and multistage flash (MSF) units need to be repaired or replaced, through retrofitting and repowering. In such situations, abandonment of the MSF process would result in a reduction in the power output of the plant. The paper refers to previous work which showed that the repowering of a typical existing power/desalination station with refurbishment/replacement of the MSF units, together with the addition of SWRO units, would result in a several-fold increase in the water and power output and a dramatic improvement in the fuel efficiency, without any additions to the existing seawater intake system. The paper emphasizes the importance of test stations/demonstration plants at existing power/desalination stations in the Middle East in order to obtain data and make improvements in the technology of higher temperature SWRO, with the feed obtained from the cooling water returning from the power plant condenser and the thermal desalination plant. The paper shows that the potential benefits would easily justify the investment in research and development required to validate this concept.     

海水淡化及其对经济持续发展的作用

经济增长、人口增加以及水体的污染,导致我国当前淡水资源严重短缺,成为经济持续发展的重要障碍。本文评述了国内外缺水的现状,系统介绍了国内外海水淡化技术的发展形势和应用规模,以及本科研组近年来在海水淡化方面的研发成果。到2009年全世界已有150个国家应用海水淡化技术,数亿人饮用或使用淡化水,淡化水以年增长率10%~12%的速度增加。10年来我国海水淡化厂的投建,以及相关产业迅速发展,使我国成为国际前十大淡化技术应用市场之一。但我国在海水淡化产业方面仍处于初期阶段,设备制造业和大型装置的开发设计能力与国际先进水平差距尚大。还需进一步加大投入,并通过国际合作加快进入国际水准的技术领域和市场竞争。