基于双缸耦合原理的阀控式能量回收系统原理设计与仿真分析

针对小规模海水淡化需要解决能量回收装置的能回效率与空间问题,将能量回收装置与压力提升泵进行集成一体化设计,研究了一种双缸耦合阀控式能量回收系统。系统两液压缸内活塞各由一个电动推杆推动,叠加高压浓海水压力实现压力交换,同时进行活塞推力的耦合控制,避免了压力交换过程中活塞的压力脉冲波动,保障了反渗透膜工作压力稳定;基于小型海水淡化装置,根据压力能流反渗透工艺节点压力流进行了计算分析,得出电动推杆推力压力0.5 MPa左右的补偿压力曲线。通过AMESim进行液压仿真分析,结果表明在系统回收率为30%,高压浓海水进口压力为4.8 MPa,增压海水压力4.6 MPa的情况下,通过压力补充增压海水压力可增压到5.0 MPa,反渗透膜压力与流量波动较小,满足反渗透海水淡化的压力需求。     

低启动转矩直驱型潮流能发电机关键参数分析与研究

文中首先从理论上分析直驱型永磁电机的齿槽转矩数学模型,讨论影响电机齿槽转矩的主要因素和降低永磁电机齿槽转矩的关键参数设计方法,分析直驱型潮流能发电机组加工运行过程中容易出现的影响电机齿槽转矩的主要原因。最后采用有限元仿真方法,结合样机实验测试,对永磁电机齿槽转矩进行对比分析。样机及仿真分析结果表明,直驱型潮流能发电机的启动转矩主要受电机电磁方案设计、样机加工误差及运行环境等因素影响。     

中小型海水淡化装置及其能量回收技术的开发和应用

海水淡化是解决沿海地区淡水资源短缺问题的重要途径,目前我国适用于海岛、舰船和钻井平台等工况的中小型海水淡化装置及其能量回收技术还不完善。文章分别介绍手持式、自增压式和撬装式(船用、岛用和风光油储一体化)中小型海水淡化装置系列的技术特点,并按类别分别介绍装置关键技术即能量回收技术的工作原理,提出研发中小型海水淡化装置与能量回收一体机的系列化产品可有效降低能耗、促进技术进步和满足国内需求。     

海水冷冻预淡化系统的试验研究

本文提出了一种基于冷冻脱盐的海水双级冷冻预淡化系统。该系统利用蒸发结晶器对海水进行冷冻,并通过振动分离与洗涤实现冰晶与卤水的分离,以此实现海水的初步脱盐,可作为反渗透淡化的预处理系统。同时,海水冷冻淡化过程中消耗的冷量可重新回收用于空调制冷,淡化成本得以有效降低。本文建立了海水双级冷冻预淡化系统的数学模型,获得了试验系统的关键设计参数,以此搭建了试验平台并完成了试验测试,并对海水双级冷冻预淡化系统进行了经济性分析。试验结果表明:经过海水冷冻预淡化系统,预淡化海水产量可维持在21~27 L/h之间;预淡化海水盐度可从35降低到约11;预淡化过程可回收总冷量7.91 kW;反渗透淡化总成本可降低约33%。     

多点液压式波浪能海水淡化系统建模与仿真

为缓解淡水资源短缺及化石能源过度使用问题,提出多点液压式波浪能海水淡化系统,该系统主要由采能装置、液压传递系统与反渗透膜海水淡化设备组成。系统的采能装置采用振荡浮子式,可将波浪能转换为浮子振荡从而被液压系统吸收达到采集波浪能的目的。为了提高液压式波浪能海水淡化系统的采能效率及淡水率,利用AMEsim软件对液压传递系统进行建模与仿真,分析了蓄能器、浮子个数及波高对液压传递系统输出响应的影响。结果表明:蓄能器能够使液压马达的输出响应更加稳定;当浮子的数量增加时,液压系统达到稳定的运行状态所需的时间更短,从而有利于提高系统的效率;波高在2 m左右时,本系统的产水量达到最大。     

新型水平轴定桨距永磁直驱潮流能发电系统设计及应用

双向潮流适应性和运行可靠性是水平轴潮流能发电系统需要解决的两个关键问题。文中研究的新型潮流能发电系统由自适应双向流水平轴定桨距潮流能透平、直驱永磁发电机、功率变换器、蓄电池储能系统以及卸荷负载组成。根据我国潮流能特点和直驱永磁发电系统的运行特性,采用翼型尾翼完成透平的双向潮流对流功能。针对离网型潮流能发电系统的功率控制,设计了基于三相不可控整流桥和双管BUCK-BOOST变换器的功率变换电路。基于Matlab/Simulink软件对20 k W潮流能发电系统各部分进行了建模与仿真分析。在实海况环境进行了现场试验。研究表明,设计的离网型水平轴潮流能发电系统能够有效地利用双向潮流能,而且在结构设计方面所采取的措施提高了系统的可靠性。     

基于MATLAB and Simulink的波浪能装置液压能量转换系统仿真研究

液压式能量转换系统是波浪能发电装置应用最为广泛的一种能量转换方式。本文针对波浪能液压能量转换系统展开了模型仿真研究,建立了带有蓄能稳压环节和液压自治控制器的波浪能装置液压能量转换系统的数学模型。基于所建立的数学模型搭建了波浪能装置液压转换系统的MATLAB and Simulink仿真框图,对系统进行仿真,并利用实海况实验得到的发电数据和仿真数据进行对比。结果显示,二者之间的相对误差较小,验证了该系统仿真模型的准确性。此外,还分别模拟了规则波和随机波输入情况下液压能量转换系统的发电特性曲线。仿真结果表明,无论是规则波还是随机波,经过液压能量转换系统之后,输出的发电特性都比较稳定,也即是利用该能量转换系统实现将不稳定的波浪能转换成稳定的电能,提高了发电质量,为后续的电力输送及并网提供了便利。     

旋转式压力交换器流体能量损失研究

为探究旋转式压力交换器运行过程中流体能量损失规律,以外驱式旋转压力交换器为研究对象,采用数值模拟方法对模型的湍流耗散率进行模拟研究。研究结果表明,转子在低压区转动时,海水侧流体能量损失先降低后升高,浓盐水侧逐渐降低;转入低压密封区,流体能量损失集中在海水侧,范围逐渐向浓盐水侧扩散;进入高压区后,海水侧流体能量损失逐渐下降,浓盐水侧逐渐升高;转子在高压密封区运行时,流体能量损失集中于浓盐水侧,能量损失范围向海水侧扩散。研究结果对旋转式压力交换器结构优化具有一定指导意义。     

升膜蒸发海水淡化实验研究

本文利用水平微槽管管外液膜蒸发进行海水淡化。分别在27 kPa压力下对初始质量分数为3.5%的盐水在不同热流密度下进行升膜欠热蒸发实验和在常压下进行不同液位蒸发实验。分析热流密度对升膜管外温度分布、结晶率及淡化效率等参数的影响及液位高低对升膜蒸发能力的影响,基于实验得出:随着热流密度的增加,海水淡化产水能耗逐渐下降,并且水平微槽管的槽道宽度较小时升膜蒸发能力较高;液位在45°时产水能耗相对较低;水平微槽管管外自顶向下逐渐扩展的氯化钠结晶面积随热流密度的增加而减小。另外,此种蒸发方式对于管外结晶有很好的自洁效果。     

西班牙海水淡化产业政策研究

西班牙是目前应用海水淡化最多的西方国家,主要发展反渗透等膜法淡化技术。西班牙政府自2004年起实施的"水资源管理和利用措施"(AGUA)计划不仅使地中海沿岸的淡化产水能力迅速增长、产水能耗不断降低,还提升了本国企业开拓海外市场的实力。西班牙政府在长期实践中制定了较完备的政策,保障淡化产业可持续发展并有效应对其导致的环境影响。文章总结了西班牙海水淡化产业的发展现状,并对产业促进和环境保护两方面的政策进行了研究,最后依据我国当前海水淡化业发展形势,参照西班牙的成功经验提出一些政策建议,旨在为我国海水淡化产业的健康发展提供有益的参考。     

碟形越浪式波能发电装置的系统研究

碟形越浪式波能发电装置是一种新型的波能发电装置,其利用蓄水池将不稳定的入射波能转换为稳定的淹没出流动能,势能转换为动能带动水轮机运转实现发电。该装置具有输出功率平稳、适应各种海况、可靠度好的的特点,对其进行深入研究,对于边远海域的岛屿经济开发、国防及海水淡化等具有十分重要的意义。     

直驱式波浪能转换系统的研究和性能优化

A direct-drive wave energy conversion system based on a three-phase permanent magnet tubular linear generator （PMTLG） and a heaving buoy is proposed to convert wave energy into electrical energy. Sufficient experimental methods are adopted to compare the computer simulations, the validity of which is verified by the experiment results from a wave tank laboratory. In the experiment, the motion curves of heaving buoy are with small fluctuations, mainly caused by the PMTLG＇s detent force. For the reduction of these small fluctuations and a maximum operational efficiency of the direct-drive wave energy conversion system, the PMTLG＇s detent force minimization technique and the heaving buoy optimization will be discussed. It is discovered that the operational efficiency of the direct-drive wave energy conversion system increases dramatically after optimization. The experiment and optimization results will provide useful reference for the future research on ocean wave energy conversion system.     

Nozzle optimization for water jet propulsion with a positive displacement pump

In the water jet propulsion system with a positive displacement （PD） pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.     

Nozzle Optimization for Water Jet Propulsion with A Positive Displacement Pump

In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.     

反渗透海水淡化技术现状和展望

反渗透膜技术于20世纪60年代取得突破性进展,促使反渗透海水淡化在近50年间高速发展,淡化产能自20世纪90年代起激增.海水反渗透(SWRO)淡化已成为目前投资最省、成本最低的利用海水制备饮用水的过程.文中主要对海水反渗透淡化的发展状况进行了介绍,如膜和组件的改进,关键设备高压泵和能量回收装置效率的提高,多种工艺过程的不断发展,包括预处理和后处理的新工艺,以及对环境的影响和相应对策等.反渗透技术的发展也推动了其他膜分离技术的进步,并扩展其应用领域.预计在不久的将来,膜技术在海水淡化和水再利用、扩大和保护水资源、循环经济、清洁生产、改造传统产业、节能减排及提高人民生活水平等方面发挥的作用会越来越显著.     

Management priorities for seawater desalination plants in a marine protected area: A multi-criteria analysis

The development of seawater desalination plants to increase water reliability in coastal areas poses a threat to the health of near shore marine ecosystems and may affect the effectiveness of marine protected areas (MPAs) that have been established to meet international conservation targets. This paper applies a multi-criteria analysis approach to quantify stakeholder groups’ priorities for seawater desalination plants that have been proposed in communities adjacent to a National Marine Sanctuary. All groups placed the highest importance on minimizing environmental impacts on protected areas and endangered species that could be affected by water intake and brine discharge emphasizing the need for integrated land and sea conservation. Minimizing socio-economic impacts on coastal communities was much less important. Stakeholders also weighted reducing pressure on water levels in rivers, streams, and aquifers as more important than increasing water for residential consumption, which may foster coastal growth rather than replacing water taken from other sources. The study further revealed differences in the importance of multiple management objectives among stakeholder groups, which highlights the need to elicit distinct priorities of all groups to understand concerns and potential conflicts of desalination with existing marine users. The analysis of consistency ratios revealed that around half of all surveyed stakeholders had high inconsistencies in their responses, which suggests either a lack of understanding of desalination, or reflects the complexity of establishing desalination plants in coastal areas adjacent to a marine protected area.     

发展海水淡化产业,缓解淡水危机

介绍并论述了国内的水资源现状、海水淡化技术在国内外的发展情况和各种海水淡化技术的适应范围与发展趋势。分析了我国实现海水淡化产业化的有利条件和不利因素 ,提出了海水淡化技术的产业化对策。     

应用“跨零-能量”法估算海洋波浪再生能资源

海洋波浪能是一种可持续和零污染的再生能源,随着自然能源日渐匮乏和全球气候变化,人类对波浪能的开发利用显得尤其重要。本文应用"跨零—能量"波浪分析的新方法,首次推导了不规则波浪的波能流垂向分布及其理论计算公式。本文研究发现,浅水波能流具有均匀的垂向分布,深水波能流集中于海表层的水体中,过渡区波能流的垂向分布介于浅水和深水波能的分布之间。研究还发现,目前海洋波能流的估算方法和现今波浪发电装置的波能采集深度缺少相关性,过高估算了海洋波浪的可发电资源。