太阳能界面蒸发器的研究进展

太阳能驱动界面蒸发技术利用太阳光在空气-水界面蒸发获取洁净水，能有效缓解水资源短缺。本文介绍了太阳能界面蒸发器的结构和蒸发原理，概述了太阳能界面蒸发器蒸发性能调控措施，从光热材料的选择、有效的热管理、水路设计、表面润湿性、活化水以及3D结构设计等多方面对光-热-蒸汽性能进行调控，并探讨了太阳能界面蒸发器在海水淡化、废水处理和协同发电等领域的广阔应用前景。     

面向水处理与有机溶剂回收的太阳能界面蒸发系统与材料

海水淡化是缓解全球淡水资源短缺的重要途径,但传统海水淡化技术受限于过大的能源消耗,而太阳能界面蒸发技术因高蒸发效率、可持续性和低成本等优点引起了人们极大的关注。太阳能界面蒸发技术利用光热转换材料将光捕获并高效地转化为热能,随之将热量传递给水分子将其蒸发收集而实现净化。本文综述了近年太阳能界面蒸发系统结构设计的演变,总结了新兴的光热材料如金属基等离子体材料、碳基材料、半导体材料、生物质材料等在海水淡化、污水处理等方面的研究,并基于系统设计理念提出了太阳能蒸发技术应用于有机溶剂纯化领域的可能性。在此基础上,对太阳能界面蒸发技术的前景和面临的挑战进行了总结,提出了太阳能界面蒸发技术与蒸汽发电、光催化、光解水产氢等多种技术的耦合。     

热法太阳能海水淡化理论研究进展综述

热法海水淡化是太阳能利用海水淡化中重要的研究方向。针对热法海水淡化蒸发冷凝过程的理论模型主要集中在以Dunkle模型为代表的盘式海水淡化模型上。近年来随着新型淡化结构的提出,太阳能集热系统的改进导致操作条件的变化,以及计算机软件、新型检测设备的开发和应用,国内外学者提出了许多新的淡化模型。该文综述了经典理论模型以及近年来新的理论模型,提出了未来的理论研究将针对建立不同腔体类型的模型以及对腔体内部物理场分布的模拟。     

太阳能海水淡化新技术综述

依据太阳能的光效应和热效应对传统的海水淡化进行分类,列举了太阳能与传统蒸馏法与渗析法的结合形式,指出了传统蒸馏法效率不高的原因,重点介绍利用冷凝潜热和提升换热效率的新型高效海水淡化技术以及反渗透的能量回收装置,认为将太阳能与传统海水淡化技术有机结合起来前景广阔,并简述了太阳能收集器的研究现状及先进技术,为太阳能海水淡化技术的进一步研究和发展提供了参考与依据.     

PDA@PPHF太阳能驱动界面蒸发性能及水质净化研究

将聚多巴胺（PDA）负载在聚丙烯中空纤维（PPHF）膜上制备PDA@PPHF复合材料,研究了其在太阳能驱动下的界面蒸发性能及水处理性能。结果表明,在1个太阳光强下,PDA@PPHF复合材料的水蒸发效率达到80.84%,是纯水自然蒸发效率的4.2倍。此外,PDA@PPHF复合材料在1 kW/m²太阳能驱动下进行了海水除盐和重金属以及染料废水净化,展现出良好的净水效果。实验结果表明,其有潜力应用于海水淡化、废水净化等领域,缓解水资源短缺问题。     

化石燃料能源零能耗太阳能光热海水淡化系统应用研究

介绍了太阳能光热产蒸汽系统和海水淡化系统,以太阳能光热作为系统动力来源,以光伏发电等可再生能源作为系统设备电力来源,将高温蒸汽和海水淡化装置在集成系统中加以融合,实现一种化石燃料能源零能耗太阳能光热海水淡化系统。并以海南某太阳能光热海水淡化示范项目为实例,对该系统进行详细的性能和效果应用分析,在该系统成功产水之后总结系统配置,展望太阳能海水淡化今后的发展方向与前景。     

新型太阳能海水淡化材料制备及其性能表征

设计一个操作简单的光热材料制备及在新型太阳能海水淡化中应用的创新性化学综合实验。通过一步浸泡涂覆的方法，制备出具有优异光热性能的材料，将其应用到新型技术——太阳能界面海水淡化中，可实现淡化水的收集和海水的浓缩。并通过实验表征材料微观形貌结构，探究太阳能利用效率，分析不同水样品的电导率。结合基础理论知识，引入前沿科学研究课题，实验方案设计既简单又具探究性，有利于培养学生的创新意识、创新思维和创新能力。     

开路热管海水淡化的热力学第2效率分析

基于平衡分析方法对利用毛细力驱动耦合低品位余热的开路热管海水淡化装置中关键节点处焓、熵、进行热力学计算和分析。结果表明,在环境温度28℃、蒸发温度40℃时,淡化过程最小分离功为2.09 J/g,系统整体效率为1.54%。损失最大过程是蒸汽冷凝成淡水,为系统总输入的67.1%,是影响开路热管海水淡化系统能效水平的关键因素。说明开路热管海水淡化过程中存在很大的不可逆程度,在提高系统热力学完善程度方面仍具备相当大的潜力。     

南京大学朱嘉教授团队成功将纳米技术应用于海水淡化

<正>南京大学朱嘉教授团队将氧化铝多孔模板与金属纳米颗粒自组装技术结合,创新性地设计了一种新型吸收体材料,在400 nm到10μm波段具有99%的太阳光吸收效率。结合新型界面光热转换设计,将这种材料应用到海水淡化上,光热蒸汽转化效率可达90%,并且水质可以满足WHO的饮用水标准。在此基础上,该团队进一步实现蒸汽焓存储利用和太阳能水电联产,依靠太阳光和自然水源两种地球上最充沛的资源,即     

新型太阳能蒸汽系统及光热材料研究进展

新型太阳能蒸汽技术是一种绿色环保的太阳能光热利用技术,因其简单高效且应用前景广泛而备受关注。高效的太阳能蒸汽系统应该同时具有优异的热管理能力、水输入和水蒸发性能以及具有宽光谱吸收光热层。本文首先从新型太阳能蒸汽系统出发,介绍分散型和漂浮型蒸汽系统,并阐述了两种蒸汽系统的基本原理、各自特点以及系统装置的研究进展;而后较为详细地介绍了各类光热材料的性能、光热转换机理及制备方法;最后探讨了新型太阳能蒸汽系统目前存在的问题以及今后的主要研究方向。     

三效管式海水淡化装置产水性能实验研究

研制了一种三效管式海水淡化装置,对其进行了定功率和太阳能加热运行实验研究,分析了该淡化装置的产水性能及影响因素。定功率实验研究表明,当淡化装置加热功率为300 W时,其性能系数最高达约1.32,提升淡化装置蒸发传热,同时降低热量耗散(辐射耗散和对流耗散),加大装置冷凝温差可以提升淡化装置性能。太阳能加热实验结果表明,淡化装置的产水性能受太阳辐射值、太阳能集热系统效率、热源稳定性、环境温度与风速等多种因素影响,特别是热源稳定性对装置性能有较大影响。     

Solar thermal desalination technologies

The use of solar energy in thermal desalination processes is one of the most promising applications of the renewable energies. Solar desalination can either be direct; use solar energy to produce distillate directly in the solar collector, or indirect; combining conventional desalination techniques, such as multistage flash desalination (MSF), vapor compression (VC), reverse osmosis (RO), membrane distillation (MD) and electrodialysis, with solar collectors for heat generation. Direct solar desalination compared with the indirect technologies requires large land areas and has a relatively low productivity. It is however competitive to the indirect desalination plants in small-scale production due to its relatively low cost and simplicity. This paper describes several desalination technologies in commercial and pilot stages of development. The primary focus is on those technologies suitable for use in remote areas, especially those which could be integrated into solar thermal energy systems.     

A small solar desalination plant for the production of drinking water in remote arid areas of southern Algeria

The common methods of desalination salt water for production of fresh water by distillation, reverse osmosis and electrodialysis are intensive energy techniques. However, in remote arid areas, the desalination needs not exceed a few cubic meters per day. This decentralised demand favours local water production by developing other desalination processes, especially those using renewable or recovered energy (solar, geothermal, etc.). Solar desalination process is one of these methods used to resolve the scarcity of fresh water. Several reviews have been published by different authors. Small production systems as solar stills can be used if fresh water demand is low and the land is available at low cost. To supply the population of remote arid lands of South Algeria with drinkable water, solar distillation of brackish waters is recommended. It satisfies some of theses demands. Solar stills are used to produce fresh water from brackish water by directly utilising sunshine. These stills represent the best technical solution to supply remote villages or settlements in South Algeria with fresh water without depending on high-tech and skills. The production capacity indicates a possible daily production of far more than 15 l/m²d. Therefore, the still has a place in the upper range of known comparable products with regards to production output. This depends on the material used and the price of the solar stills and their accessories. The best working temperature solves most problems. Small, modular high-performance stills with features like the possibility of decentralised use, less maintenance and robust construction can help to reduce fresh water scarcity. The recent development of stills based on new concepts and heat recovery has been successful. The technical optimization is still in process today, it aims to improvement of the efficiency of these distillers. In our research work, a plant for brackish water distillation by directly sunshine and heat recovery was constructed and investigated experimentally and theoretically in South Algeria. This study aims the improvement of the performance of this solar distillation plant, conducted under the actual insulation, for brackish underground geothermal water desalination.     

Analysis of a mechanical vapor compression desalination system

The mechanical vapor compression (MVC) desalination system is based on distillation of seawater. The system is basically a heat exchanger that is an evaporator/condenser. The heat required to evaporate water which flows on one side of a heat transfer surface is supplied through the simultaneous condensation of the distillate-producing vapor on the other side of the surface. That is, the latent heat is exchanged in the evaporation—condensation process within the system. A compressor is the driving force for this heat transfer and provides the energy required separating the solution and overcoming dynamic pressure losses and other irreversibilities. In this study, the operation characteristics of a low-temperature MVC desalination system are investigated. In the modeling, the overall energy balance and mass balance equations and LMTD method for heat transfer are used. The tube diameter and the tube length were taken at 0.025 m and 9 m, respectively. The main dependent parameters, the compressor work and the mass flow rate of the distilled water, were investigated against the independent parameters, the evaporation side pressure, the condensation side pressure, and the water inlet temperature.     

Solar desalination with a humidification-dehumidification cycle: performance of the unit

The closed air cycle humidification-dehumidification process was used for water desalination using solar energy. The circulated air by natural or forced convection was heated and humidified by the hot water obtained either from a flat plate solar collector or from an electrical heater. The latent heat of condensation was recovered in the condenser to preheat the saline feed water. Two units of different sizes were constructed from different materials. The productivity of these units was found to be much higher than those of the single-basin stills. Moreover, these units were capable of producing a large quantity of saline warm water for domestic uses other than drinking. No significant improvement in the performance of the desalination units was achieved using forced air circulation at high temperatures. While at lower temperatures, a larger effect was noticed. This can be related to the low heat and mass transfer coefficients at low temperatures and to the non-linear increase in the water vapor pressure with temperature.     

New experimental aspects of the carrier gas process (CGP)

The carrier gas process (CGP) based on humidification and dehumidification is a new interesting process (with respect to previous conventional processes such as multistage flash and reverse osmosis) for water desalination. The CGP contains several advantages such as flexibility in capacity, moderate installation and operating cost, possibility of using a wide range of thermal energies (geothermal, solar, recovered, direct fossil fuel, etc.) and simplicity (atmospheric pressure). The aim of this paper is to present the principal and characteristics of this technique based on experimental investigation. The present pilot plant unit consists of two packed columns, humidification and dehumidification, one heat exchanger and one air pre-heater. Most investigators have used solar thermal energy as the source for heating the saline water, but in this work electrical energy was used for heating the air stream. Besides this point most investigators have used a coil heat exchanger for condensation of fresh water but in the present work a packed column was used instead to do the same job. The experimental results of the work that was carried out at Bushehr Port, southern Iran, were: the effect of air pre-heater and coolant water temperatures, air, saline water, recirculating fresh water and coolant water flow rates on the amount of produced fresh water per unit of heat duty and fresh water production flow rate. It was found that the performance of the system strongly depended on the temperature and flow rate of the air pre-heater and the temperature and flow rate of the coolant water. However, it depended weakly on the flow rate of the saline water and fresh water re-circulation. It is expected that the unit would be of great potential for saline water desalination in arid areas and isolated islands.     

新型闭式太阳能海水淡化装置及其性能模拟

本文提出了一种闭式海水淡化装置,阐述了系统的工作原理,建立了相应的数学模型。就冷却水流量、海水喷淋量、集热器面积、蒸发器尺寸等因素对系统淡水产量的影响情况进行了计算机模拟,根据实验测得的气象数据对一天内系统淡水产量随时间变化情况进行了模拟,并根据典型的月平均日气象数据对系统一年内每个月的系统性能进行了分析。分析表明,不计系统夜间运行时的淡水产量,在西安地区系统淡水产量可以达到4.6kg/d.m2。     

Energy and exergy analyses of seawater desalination system integrated in a solar heat transformer

Among the numerous options to improve the energy efficiency of desalination plants stands out the absorption heat transformer. A heat transformer is a device, which can deliver heat at a higher temperature than the temperature of the fluid by which it is fed. Solar thermal energy can be used as heat input for single effect heat transformer while the high grade thermal energy delivered by the heat transformer can be used as heat source for water desalination.In this paper, an attempt has been made to study the combination: flat plate solar collectors, a single effect heat transformer and desalination system (distillation process) used to provide a beach house located in Skikda (East of Algeria; Latitude 36.52°N, Longitude 6.57°E) with drinking water. This system produces about 500 l of drinking water per day in July.Mathematical models of the solar flat plate collectors (FPC), absorption heat transformer (AHT) operating with the water/lithium bromide solution and the overall desalination system (WP) were developed to simulate the performance of this combination system. The energy and exergy analyses are carried out for each component of the system. All exergy losses that exist in this solar desalination system are calculated. Energy and exergy efficiencies are estimated.     

Comparison of solar thermal technologies for applications in seawater desalination

This paper deals with a global analysis of the use of solar energy in seawater distillation under Spanish climatic conditions. Static solar technologies as well as one-axis sun tracking were compared. Different temperature ranges of the thermal energy supply required for a desalination process were considered. At each temperature range, suitable solar collectors were compared in some aspects as: (1) fresh water production from a given desalination plant; (2) attainable fresh water production if a heat pump is coupled to the solar desalination system; (3) area of solar collector required for equivalent energy production. Results showed that direct steam generation (DSG) parabolic troughs are a promising technology for solar-assisted seawater desalination.