纳米材料改善硝酸熔盐传蓄热性能的研究进展EI北大核心CSCD

聚光式太阳能热发电是解决能源和环境矛盾的理想途径,传热蓄热技术是光热发电的重要环节,在此需要解决的关键问题是传热蓄热介质。熔盐作为储蓄热介质具有明显优势。国内外运行的光热电站中大多使用二元硝酸熔盐(Solar salt)与三元硝酸熔盐(Hitec),但二者传蓄热性能均欠佳,影响了太阳能的利用效率。纳米材料的独特空间结构,使其具有优异的导热性能、良好的稳定性等,将其作为添加剂引入到硝酸熔盐体系中,有望改善材料的传热蓄热等热物性能,进而提高太阳能光热利用的效率,降低发电成本。本文综述了纳米金属粒子、纳米金属氧化物、纳米碳材料和其他无机纳米材料作为添加剂掺杂到硝酸熔盐体系中的相关研究,论述了改性后熔盐热物性的变化并探讨了作用机理,以期为制备优异热性能的储能熔盐提供参考。未来的研究可重点关注热物性测试、传热机理、构效关系和工业化中试,将具有优异的传蓄热性能的硝酸熔盐应用在太阳能光热发电领域,在清洁能源开发利用方面发挥更重要的作用。     

The possibility of high-temperature heat capacity measurements by differential scanning calorimetry

We have been conducting series of heat capacity measurements by differential scanning calorimetry (DSC) on various latent thermal storage materials such as NaOH-NaNO₃. Our concern is now shifting to higher temperature applications of latent thermal storage: space solar dynamic power systems (solar thermal electric power generation systems in space) and so on. Such applications require storage materials which can be operated above 1000 K. Needs for heat-capacity measurements at higher temperatures are increasing. In the present paper, some results of our heat capacity measurements by DSC at intermediate temperatures are presented. Several items which should be considered in order to realize the heat capacity measurements above 1000 K by DSC are discussed.Paper presented at the Second U.S.-Japan Joint Seminar on Thermophysical Properties, June 23, 1988, Gaithersburg, Maryland, U.S.A.     

The development of metal hydrides using as concentrating solar thermal storage materials

Metal hydrides high temperature thermal heat storage technique has great promising future prospects in solar power generation, industrial waste heat utilization and peak load regulating of power system. This article introduces basic principle of metal hydrides for thermal storage, and summarizes developments in advanced metal hydrides high-temperature thermal storage materials, numerical simulation and thermodynamic calculation in thermal storage systems, and metal hydrides thermal storage prototypes. Finally, the future metal hydrides high temperature thermal heat storage technique is been looked ahead.     

风光储联合发电运行技术研究

随着能源需求的日益增长和新能源的快速发展,利用风能、太阳能的发电技术已经逐步成熟,且在电网中的渗透率也在不断提高。为弥补风能、太阳能发电所带来的功率不稳定、电能质量低等问题,有必要对风能、太阳能、储能联合发电进行深入研究。文中依据简单平抑方法、考虑一定约束的平抑方法、考虑功率预测与人工智能的平抑方法对储能的平抑控制策略进行了归纳总结。在储能平抑风光波动的研究中滤波算法是最为常见的方法,加入一定的约束会使平抑效果更佳,储能平抑配合精准的预测使整个系统更加平滑。多储能技术混合可以发挥各储能技术优越性。加入储能装置的风光储互补系统可以有效降低原风光互补系统对电网的不利影响。可以在更高程度上平滑风光发电系统的输出特性,增加电网对可再生能源的吸收接纳程度,取得良好的经济和社会效益。     

Generating capacity adequacy evaluation of small stand-alone power systems containing solar energy

This paper presents a time sequential simulation method for generating capacity adequacy evaluation of small stand-alone power systems containing solar energy (PSCSE) operating in parallel with battery storage. The reliability performance of such a system is quite different from one containing only conventional generation. This is due to the chronological random nature of the solar radiation level and the dependencies associated with the power output of every photovoltaic (PV) generating unit at the site location. The adequacy of a PSCSE depends on various factors such as the solar radiation level, the battery size and charging (discharging) capability, the failure/repair characteristics of the diesel generator (DG) and the PV unit, the system load profile and peak load and the solar energy penetration level in the system etc. The methodologies, results and discussions presented in this paper should provide valuable information to utilities involved in planning and operating stand-alone systems utilizing both conventional and solar energy.     

新型光伏储电原位集成电池研究进展

随着光伏智能电子产品日益融入到日常生活,人们不仅对高性能光伏发电设备的需求增加,同时对智能化、可持续和快速充电/放电能源集成设备的需求也急剧增加,将能量产生部件和能量存储部件结合成独立设备已经成为一种极具有吸引力和挑战性的前沿技术。原位逐层制备光电转换功能薄膜与储电功能薄膜并组装,获得光伏储电原位集成电池的技术,既减少了太阳光波动对能量输出的影响,又可以实现光伏自供电、弱光缓冲和可穿戴等功能,因此具有良好的发展前景。本文综述了硅基光伏储电原位集成电池、敏化光伏储电原位集成电池、钙钛矿光伏储电原位集成电池的最新研究成果,介绍了此类新型电池性能的评价方法,分析了其工作原理、构造特点和性能参数,并对此新兴研究领域的发展趋势进行了展望。     

Integrated solar capacitors for energy conversion and storage

Solar energy is one of the most popular clean energy sources and is a promising alternative to fulfill the increasing energy demands of modern society.Solar cells have long been under intensive research attention for harvesting energy from sunlight with a high power-conversion efficiency and low cost.However,the power outputs of photovoltaic devices suffer from fluctuations due to the intermittent instinct of the solar radiation.Integrating solar cells and energystorage devices as self-powering systems may solve this problem through the simultaneous storage of the electricity and manipulation of the energy output.This review summarizes the research progress in the integration of new-generation solar cells with supercapacitors,with emphasis on the structures,materials,performance,and new design features.The current challenges and future prospects are discussed with the aim of expanding research and development in this field.     

硝酸熔盐储热材料在太阳能利用中的研究进展

随着全球经济的快速发展,能源危机日渐凸显,太阳能作为可再生能源的一种,越来越受到人们的重视.因此,如何高效利用太阳能资源值得深究.熔盐具有良好的蓄热特性,在石化、电池及冶金行业中发挥着很大的作用,尤其可以作为传热蓄热介质应用于太阳能热发电和太阳能制氢中.其中硝酸盐的特性较为适合用于熔盐储热材料.主要针对硝酸熔融盐体系,一是介绍了硝酸熔融盐体系在太阳能方面的应用,二是介绍了国内外学者对此体系的物化性质研究,如工作温度范围、热力学性质及热稳定性等.通过对比,总结了不同混合熔融盐各项性能的异同.指出了硝酸熔融盐性能深入研究的方向,为硝酸熔盐在能源开发利用和环境保护等方面发挥更重要的作用提供了重要参考.     

Long-term heat storage with NaOH

To reach high solar energy fractions for building heat supply, several seasonal thermal storage techniques have been developed and tested so far. Besides ground storage techniques, thermo-chemical techniques with high heat storage capacity and virtually no heat losses in the storage state are most promising. This paper deals with closed sorption systems and focuses on the concept with sodium hydroxide (NaOH)-water as the working pair. In an experimental prototype system setup, vapor pressure and boiling temperatures of highly concentrated sodium lye, as well as heat charge and discharge processes of the storage under low-pressure conditions were analyzed or verified. The storage capacity is limited by the temperature levels of the produced heat and by the solidification of the NaOH lye. The results for the single-stage prototype show that for charging the storage, solar heat input at 150 °C is needed, and that, compared to conventional water storage, the system-volume-related heat capacity could be increased by a factor of 6 for low-temperature space heating (40 °C) and by a factor of 3 for domestic hot water supply (65-70 °C). Future systems shall be built as a double-stage system in one integral vacuum container, containing solution tanks, heat exchangers, piping, and pumps.     

相变储能材料的研究与发展

储能技术是通过物理或化学变化将某种能量存储,然后在后续过程中释放利用的技术,现多用于电力系统、交通运输、太阳能利用和移动电子等设备中,能够有效节约能源和提高能源利用率。相变储能材料是相变储能技术的关键载体,对其应用起着重要作用。本文对相变储能材料的基本特征、应用领域、储能原理以及分类等方面作了简要的介绍。并依据成分分类,对目前国内外研究的无机类、有机类、金属基及复合类相变储能材料进行了综述。详细介绍了不同材料的种类、性质、优缺点、适用范围等。最后指出了当前相变储能材料存在的不足,并展望了相变储能材料未来的发展方向和应用前景。     

金属相变储热技术在太阳能热发电系统中的应用分析

对聚光类太阳能热发电中的储热技术作了介绍;针对太阳能热发电系统中通常需要配备热储存设备以最大程度发挥太阳能热发电系统发电能力的特点,提出了利用熔点温度适宜的金属相变材料作为储热介质的观点,并根据已有的研究成果对集吸热、储能与产生蒸汽于一体的金属相变储热蒸汽锅炉在聚光类尤其是塔式太阳能热发电系统中应用的可行性进行了理论分析和探讨,为下一步的实验工作打下基础。     

Local Electrochemical Functionality in Energy Storage Materials and Devices by Scanning Probe Microscopies: Status and Perspectives

Energy storage and conversion systems are an integral component of emerging green technologies, including mobile electronic devices, automotive, and storage components of solar and wind energy economics. Despite the rapidly expanding manufacturing capabilities and wealth of phenomenological information on the macroscopic device behaviors, the microscopic mechanisms underpinning battery and fuel cell operations in the nanometer–micrometer range are virtually unknown. This lack of information is due to the dearth of experimental techniques capable of addressing elementary mechanisms involved in battery operation, including electronic and ion transport, vacancy injection, and interfacial reactions, on the nanometer scale. In this article, a brief overview of scanning probe microscopy (SPM) methods addressing nanoscale electrochemical functionalities is provided and compared with macroscopic electrochemical methods. Future applications of emergent SPM methods, including near field optical, electromechanical, microwave, and thermal probes and combined SPM‐(S)TEM (scanning transmission electron microscopy) methods in energy storage and conversion materials are discussed.     

Toward Wearable Self‐Charging Power Systems: The Integration of Energy‐Harvesting and Storage Devices

One major challenge for wearable electronics is that the state‐of‐the‐art batteries are inadequate to provide sufficient energy for long‐term operations, leading to inconvenient battery replacement or frequent recharging. Other than the pursuit of high energy density of secondary batteries, an alternative approach recently drawing intensive attention from the research community, is to integrate energy‐generation and energy‐storage devices into self‐charging power systems (SCPSs), so that the scavenged energy can be simultaneously stored for sustainable power supply. This paper reviews recent developments in SCPSs with the integration of various energy‐harvesting devices (including piezoelectric nanogenerators, triboelectric nanogenerators, solar cells, and thermoelectric nanogenerators) and energy‐storage devices, such as batteries and supercapacitors. SCPSs with multiple energy‐harvesting devices are also included. Emphasis is placed on integrated flexible or wearable SCPSs. Remaining challenges and perspectives are also examined to suggest how to bring the appealing SCPSs into practical applications in the near future.     

蓄冷空调在大型公共建筑中的应用分析

介绍了水蓄冷、静态冰蓄冷、动态冰蓄冷系统的特点及对平衡电网负荷的作用,并以广州白云机场2号航站楼为例,对各种系统的应用进行了技术和经济分析,得出各种系统的特性、对电网削峰填谷的效果及存在电价差时水蓄冷的经济优势.     

新型布雷登塔式太阳能热发电系统

太阳能热发电通常以水工质吸热作为第1代,以熔盐吸热作为第2代,以空气、超临界二氧化碳或固体粒子作为介质的布雷登循环系统称为第3代太阳能热发电系统。通过采用空气或陶瓷粒子作为吸热介质,采用干热存储介质（如耐火砖和陶瓷材料等）进行规模化储热,能提高系统效率和降低成本,系统的储热能力可保证电站在任何时候都按照电网调度要求发电。采用标准化模块设计,通过工厂化制作,使电站设计、设备生产、安装、调试和运行都大为简便,储存的热量可用于食品加工、干燥、农业应用等。根据美国能源部的研究,具有储热功能的模块配备小型燃气型透平可实现快速启停,改善电网电压和频率质量。     

Cooling machine with integrated cold storage

The use of thermal solar energy systems in combination with thermal driven sorption chillers for climatisation gains increasing influence. For solar assisted cooling a backup system is necessary for times when no solar energy is available. Absorption chillers driven by a combination of thermal collectors and conventional furnaces, which supply the driving heat in times of no insolation, suffer from an abrupt drop of the system efficiency (COP) during the operation change. This drop in COP can be avoided by installing a combined heat buffer and storage feature. Various possibilities of heat storage features are compared. An experimental setup of a high-efficient absorption chiller which facilitates the supply of a constant load of coldness at constantly high COP in spite of periodically available driving heat is presented.     

Nonsiliceous Mesoporous Materials: Design and Applications in Energy Conversion and Storage

In this work, the progress in the design of nonsiliceous mesoporous materials (nonSiMPMs) over the last five years from the perspectives of the chemical composition, morphology, loading, and surface modification is summarized. Carbon, metal, and metal oxide are in focus, which are the most promising compositions. Then, representative applications of nonSiMPMs are demonstrated in energy conversion and storage, including recent technical advances in dye‐sensitized solar cells, perovskite solar cells, photocatalysts, electrocatalysts, fuel cells, storage batteries, supercapacitors, and hydrogen storage systems. Finally, the requirements and challenges of the design and application of nonSiMPMs are outlined.     

纳米填料增强硝酸盐复合材料传储热性能的研究进展

硝酸盐凭借成本低、工作温度范围广等优点作为储热介质被广泛应用于聚光太阳能热发电系统。向硝酸盐中掺入纳米填料会使其传储热性能显著提高,可有效提高太阳能光热发电系统的发电效率。本文介绍了常见硝酸盐基纳米复合材料组分及制备方法,分析了纳米填料掺杂浓度和尺寸对硝酸盐纳米复合材料传储热性能的影响及其增强机制,最后指明硝酸盐纳米复合材料未来的研究方向。     

Optimization of battery and wind technologies: Case of power deviation penalties

Incorporation of wind power with the current power grids and electricity related markets is an arduous task because of its volatile essence. As a result, there is a need for extra capacity as backup as wind power and battery are integral to one another. This research delves into the utilization of a lithium-ion battery storage system to reduce day ahead bid changes and market integration issues that exist due to sporadic disposition of wind power in Turkey. This research uses data from a 30 MW wind farm and considers added Lithium-ion batteries. Financial analyses have been carried out with lithium-ion investment, variable costs, and current market prices considered. Net present value of both systems was discovered as positive. This research advocates the use of storage systems for the developing countries such as Turkey. It demonstrates that with the drop of battery prices, storage systems have the potential to serve as more applicable options. Furthermore, the importance of energy storage regulation for storage system to enter the market is demonstrated.     

Use of variable geometry ejector with cold store to achieve high solar fraction for solar cooling

Concerns over environmental impact of heat pump cooling systems have led to a revival of solar ejector cooling systems. In order to achieve high solar fractions, the common approach is to increase the solar collector area. However, this is costly and does not provide cooling after sunset. This paper uses software modelling to examine the use of variable geometry ejectors and cold stores to increase the annual yield of an ejector system. The study concludes that a variable geometry ejector is able to increase yield by 8–13% compared to a fixed geometry ejector. However, a 46–50% increase in solar fraction is available if a 60 MJ cold store is included compared to a fixed geometry ejector without storage and up to 63% increase in solar fraction is available if a variable geometry ejector and 60 MJ cold store is used. Alternatively, the modelling shows how the solar collector area may be decreased if a cold store is used and this may benefit the capital and operating cost of the system.