Harnessing overlapped temperature-salinity gradient in solar-driven interfacial seawater evaporation for efficient steam and electricity generation

Solar-driven interfacial water evaporation(SIWE)offers a superb way to leverage concentrated solar heat to minimize energy dissipation during seawater desalination.It also engenders overlapped temperaturesalinity gradient(TSG)between water-air interface and adjacent seawater,affording opportunities of harnessing electricity.However,the efficiency of conventional SIWE technologies is limited by significant challenges,including salt passivation to hinder evaporation and difficulties in exploiting overlapped TSG simultaneously.Herein,we report self-sustaining hybrid SIWE for not only sustainable seawater desalination but also efficient electricity generation from TSG.It enables spontaneous circulation of salt flux upon seawater evaporation,inducing a self-cleaning evaporative interface without salt passivation for stable steam generation.Meanwhile,this design enables spatial separation and simultaneous utilization of overlapped TSG to enhance electricity generation.These benefits render a remarkable efficiency of90.8%in solar energy utilization,manifesting in co-generation of solar steam at a fast rate of 2.01 kg m^(-2)-h^(-1)and electricity power of 1.91 W m^(-2)with high voltage.Directly interfacing the hybrid SIWE with seawater electrolyzer constructs a system for water-electricity-hydrogen co-generation without external electricity supply.It produces hydrogen at a rapid rate of 1.29 L h^(-1)m^(-2)and freshwater with 22 times lower Na+concentration than the World Health Organization(WHO)threshold.

Assessment of Electric Power Generation via Water Hyacinths and Agricultural Waste

The importance and the necessary of researches on renewable energy have become a hot topic in recent years due to climate change and global warming. In addition, the fossil fuel reserves is facing rapid depletion on the earth. Currently, most researches have concentrated on producing biogas for heating, lighting, drying, cooking but lack in researching on electricity production because the possibility of producing biogas at households are common at small scale. Studying on alternative energy sources to replace traditional fuel for electric power generation brings new chances and great opportunities for development. This study presents an assessment electric power generation via water hyacinths and agricultural waste. In this paper, the evaluation electric power is generated by operating internal combustion engines which use biogas fuel to replace traditional fuel （diesel, gasoline）. The results of the studies were demonstrated by experiments on the renewable energy production system at Hoa An Biotechnology Research and Experimental Center of Cantho University.

Insights into the role of oxygen-containing functional groups on carbon surface in water–electricity generation

A deep understanding of the electricity generation mechanism from the interaction between water molecules and carbon material surfaces is attractive for next-generation water-based energy conversion and storage systems.Herein,an asymmetric generator was assembled based on functionalized carbon nanotubes films to investigate the relative contribution from various oxygen functional groups on carbon surface to the water-electrical performance.Experiments and calculations demonstrate that the electricity mainly originates from the water molecule adsorption by carboxyl groups and dissociation of functional groups on carbon surface,which leads to the formation of electrical double layers at interfaces.This device allows the electricity generation with a variety of water sources,such as deionized water,tap water,as well as seawater.In particular,the generator based on carboxyl carbon nanotubes can induce a voltage of over 200 mV spontaneously in natural seawater with the power density of about 0.11 mW·g^(−1).High voltages can be achieved easily through the series-connection strategy to power electronic products such as a liquid crystal display.This work reveals the dominant role of carboxyl groups in carbon-based water–electricity conversion and is expected to offer inspiration for the preparation of carbon materials with high electrical performance.

Renewable Energy:Wind Turbines,Solar Cells,Small Hydroelectric Plants,Biomass,and Geothermal Sources of Energy

In this paper,we present five basic types of renewable energy sources,namely:wind turbines,solar cells,small hydroelectric plants,biomass,and geothermal sources of energy.Wind turbines transform energy of wind into electrical energy,solar cells transform energy of sun into electric energy,hydroelectric plants transform energy of water into electric energy,devices or machines can be constructed to transform energy of biomass into heat energy,and geothermal energy into some form of energy.In this paper we present basic information and reasons why there is need today to use these forms of energy—called green energies,we present how these devices or machines function,and we propose for future work design of typical devices or machines that will satisfy basic functional needs.

Tortuosity regulation of two-dimensional nanofluidic films for water evaporation-induced electricity generation

Water evaporation-induced electricity generation is a promising technology for renewable energy harvesting.However,the output power of some reported two-dimensional(2D)nanofluidic films is still restricted by the relatively weak water–solid interactions within the tortuous nanochannels.To further enhance the comprehension and utilization of water–solid interactions,it is of utmost importance to conduct an in-depth investigation and propose a regulatory concept encompassing ion transport.Herein,we propose tortuosity regulation of 2D nanofluidic titanium oxide(Ti_(0.87)O_(2))films to optimize the ion transport within the interlayer nanochannel for enhanced efficiency in water evaporation-induced electricity generation for the first time.The significance of tortuosity in ion transport is elucidated by designing three 2D nanofluidic films with different tortuosity.Tortuosity analysis and in situ Raman measurement demonstrate that low tortuosity can facilitate the formation of efficient pathways for hydrated proton transport and promote water–solid interactions.Consequently,devices fabricated with the optimized 2D nanofluidic films exhibited a significantly enhanced output power density of approximately 204.01μW·cm^(−2),far exceeding those prepared by the high-tortuosity 2D nanofluidic films.This work highlights the significance of the construction of low tortuosity channels for 2D nanofluidic films with excellent performance.

A hybrid fuel cell for water purification and simultaneously electricity generation

The development of highly efficient energy conversion technologies to extract energy from wastewater is urgently needed,especially in facing of increasing energy and environment burdens.Here,we successfully fabricated a novel hybrid fuel cell with BiOCl-NH_(4)PTA as photocatalyst.The polyoxometalate(NH_(4)PTA)act as the acceptor of photoelectrons and could retard the recombination of photogenerated electrons and holes,which lead to superior photocatalytic degradation.By utilizing BiOCl-NH_(4)PTA as photocatalysts and Pt/C air-cathode,we successfully constructed an electron and mass transfer enhanced photocatalytic hybrid fuel cell with flow-through field(F-HFC).In this novel fuel cell,dyes and biomass could be directly degraded and stable power output could be obtained.About 87%of dyes could be degraded in 30 min irradiation and nearly 100%removed within 90 min.The current density could reach up to~267.1μA/cm^(2);with maximum power density(Pmax)of~16.2μW/cm^(2) with Rhodamine B as organic pollutant in F-HFC.The power densities were 9.0μW/cm^(2),12.2μW/cm^(2),and 13.9μW/cm^(2) when using methyl orange(MO),glucose and starch as substrates,respectively.This hybrid fuel cell with BiOCl-NH_(4)PTA composite fulfills the purpose of decontamination of aqueous organic pollutants and synchronous electricity generation.Moreover,the novel design cell with separated photodegradation unit and the electricity generation unit could bring potential practical application in water purification and energy recovery from wastewater.

Laser-induced periodic surface structured electrodes with 45% energy saving in electrochemical fuel generation through field localization

Electrochemical oxidation/reduction of radicals is a green and environmentally friendly approach to generating fuels.These reactions,however,suffer from sluggish kinetics due to a low local concentration of radicals around the electrocatalyst.A large applied electrode potential can enhance the fuel generation efficiency via enhancing the radical concentration around the electrocatalyst sites,but this comes at the cost of electricity.Here,we report about a~45%saving in energy to achieve an electrochemical hydrogen generation rate of 3×10^(16) molecules cm^(–2)s^(–1)(current density:10 mA/cm^(2))through localized electric field-induced enhancement in the reagent concentration(LEFIRC)at laser-induced periodic surface structured(LIPSS)electrodes.The finite element model is used to simulate the spatial distribution of the electric field to understand the effects of LIPSS geometric parameters in field localization.When the LIPSS patterned electrodes are used as substrates to support Pt/C and RuO_(2) electrocatalysts,the η_(10) overpotentials for HER and OER are decreased by 40.4 and 25%,respectively.Moreover,the capability of the LIPSS-patterned electrodes to operate at significantly reduced energy is also demonstrated in a range of electrolytes,including alkaline,acidic,neutral,and seawater.Importantly,when two LIPSS patterned electrodes were assembled as the anode and cathode into a cell,it requires 330 mVs of lower electric potential with enhanced stability over a similar cell made of pristine electrodes to drive a current density of 10 mA/cm^(2).This work demonstrates a physical and versatile approach of electrode surface patterning to boost electrocatalytic fuel generation performance and can be applied to any metal and semiconductor catalysts for a range of electrochemical reactions.

Proposal of a Solar Thermal Power Plant at Low Temperature Using Solar Thermal Collectors

To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surface solar collectors, so working at low temperature (i.e., below 100°C). This power plant is aimed at warm countries, i.e., the ones mainly located between -40° and 40° latitude, having available space along their coast. This land based plant, to install on the seashore, is technologically similar to the one used for OTEC (Ocean Thermal Energy Conversion). This plant, apart from supplying electricity with a much better thermodynamic efficiency than OTEC plants, has the main advantage of providing desalinated water for drinking and irrigation. This plant is designed to generate electricity (and desalinated water) night and day and all year round, by means of hot water storage, with just a variation of the power delivered depending on the season.

多年调节水电站节水增发电量考核计算方法研究

黄河上游梯级联合调度以龙羊峡和刘家峡两库联合调节为原则 ,而龙羊峡电站节水增发电量考核不同于一般的年调节电站或径流电站 ,需以梯级联合运行调度图为依据 ,根据多年调节水库的特点 ,提出库存水量转换成电量的方法 ,将计算电量与库存电量之和作为考核电量。实例计算结果表明 。

水驱油岩石物理响应特征实验研究

在油层注水开发过程中,随着注入水与原始地层水逐渐混合,油层被水淹,由于注入水与原始地层水矿化度不同,造成混合液电阻率逐渐发生变化,相应的地层电阻率、地层电阻率增大系数、岩电参数b和n等均发生相应变化。选取朝阳沟油田10块岩样,模拟地层高温高压,开展了水驱油岩电相渗实验研究,从理论上对各储层参数的变化规律进行了探讨。研究结果为水驱地层含水饱和度模型优选及参数的正确选取提供了理论依据。根据实验结果计算的目前含水饱和度精度达到5.4%,满足注水开发中水淹层测井解释的需求。

从微生物细胞中收集生物降解塑料PHB

用自制的ＮａＣｌＯ 溶液毁解生物细胞，离心分离收集ＰＨＢ，ＰＨＢ 的纯度随ＮａＣｌＯ 溶液中Ｃｌ 含量的增加而增加。以含ＰＨＢ 为４０ ％ 的生物细胞为原料，当ＮａＣｌＯ 溶液中Ｃｌ 的含量为６．９ ％ 、ｐＨ 为１１ 、处理时间为３０ ｍｉｎ 时，获得ＰＨＢ 的纯度为８９．２ ％ ，收率为９６．９ ％ 。在处理过程中，ＰＨＢ 的分子量会发生一定程度的降解，其粘均分子量 －Ｍη从３．５ ×１０５ 下降为０．４９ ×１０５ 。

双模热水器接力加热的FLUENT仿真研究

在热水器的使用中,出水温度是否恒定,是否能提供足够的用水量,这些对用户的舒适性都有很大的影响。针对目前销量较大的储水式电热水器存在预热时间长、保温耗电量高、占用空间大、水量有限且出水温度不稳定等问题,提出了一种新型的双模电热水器,既有即热式热水器的即开即用的即热功能和储水式电热水器的预热功能,又能有效解决即热式热水器的大电流安全性难题和储水式电热水器的加热速度慢、保温能耗高、热效率低等问题。利用计算流体动力学CFD软件FLUENT中RNG k-ε的湍流模型,对双模热水器进行了接力加热特性的三维数值瞬态模拟,分析了热水器静态加热、动态放水接力加热过程的流场特点以及出水口平均温度、水箱平均温度和其他点的温度随时间变化的规律,研究结果表明,20L双模热水器比相同容积的储热式热水器增容30L。

阳离子表面活性剂提高低渗透油藏注水效率机理

针对长庆油田低渗透油藏注水困难的问题,采用可见光分光光度计和微电泳仪研究了一种水溶性双阳离子表面活性剂在岩石颗粒表面的吸附特性和对岩石颗粒表面电性的影响规律,选用长庆油田长6地层的岩心,评价了该处理剂的抑制黏土膨胀效果及降压增注能力。结果表明,表面活性剂在岩心颗粒表面的吸附等温线遵循Langmuir吸附规律,与岩心颗粒之间的静电引力较大。吸附后,使岩石表面电势减弱,减弱了黏土的膨胀,对黏土颗粒的运移具有一定的抑制作用,因而能够降低注入水对岩心渗透性的伤害程度,明显提高低渗透油藏注水效率。

水电站节水增发电量考核软件研制

介绍了节水增发电量考核指标中的节水增发电量、水能利用提高率的计算原理。应用软件工程学思想,以PowerBuilder(PB)为开发工具开发节水增发电量考核软件,软件简单适用,效益明显。

梯级水电站优化调度与节能减排

加大水电在总能源供应中的权重是履行我国政府对国际社会节能减排承诺的重要途径,流域梯级水电站优化调度可增加可观的发电量,相当于在不增加投资、不需要移民的情况下多建了大、中型水电站。这些举措对加大非化石能源的消费比重、减少大气污染物排放有着重要意义。

华中电网减少水电弃水增发电量问题探讨

充分利用水能资源是能源可持续发展战略的重要组成部分 ,优先开发水电是世界各国电力发展的共同选择。在华中地区水能资源及水电开发利用现状的基础上 ,针对华中电网调峰矛盾突出、水电弃水调峰损失电量大等问题 ,提出了华中电网减少水电弃水增发电量的对策和建议 ,并结合实际分析了可行性和合理性。

水电能源的增效节能措施探讨

论述了节能的必要性,分析了水电站工程建设和管理方面存在的水电能源流失问题,探讨了有关增效节能的措施,并提出优化管理的建议。

电动给水泵节能优化增容改造及应用

山西漳泽电力股份有限公司蒲州发电分公司两台亚临界300MW空冷机组各配备三台上海电力修造厂生产的50%容量DG600-240V型锅炉主给水泵及FA1D56A型前置泵,正常情况下2台给水泵运行,1台备用。该机组经常处于低负荷调峰状况下运行,泵组运行效率不高。该公司对#2机2C主电动给水泵节能优化增容改造,针对各部分提出改造措施:确定增容改造后的最佳设计参数、主泵实施增容提效改造、叶轮各部分进行优化、提高给水泵检修维护工艺、管路系统运行优化等。

600MW发电机组采用汽动给水泵优化运行的优势

介绍了火力发电厂600 MW汽轮发电机组中锅炉给水泵小汽轮机拖动技术,其意义相当于主机增容改造,节约了大量的厂用电,新增了发电量,增加售电主营收入。

大涝坝1号构造注水开发地面工艺流程优化

大涝坝1号构造DLK8井注水开发,原地面工艺注水流程存在注水压力高、注水回流量大、撬块震动较大等问题。通过调整柱塞大小、流程优化等经济可行的对策,解决了回流量大、撬块震动过大问题,提高了注水水质,起到了节电增油的效果。为边远井撬装注水流程的开发建设提供了借鉴和参考。