Progress in Research and Development of Molten Chloride Salt Technology for Next Generation Concentrated Solar Power Plants

Concentrated solar power(CSP)plants with thermal energy storage(TES)system are emerging as one kind of the most promising power plants in the future renewable energy system,since they can supply dispatchable and low-cost electricity with abundant but intermittent solar energy.In order to significantly reduce the levelized cost of electricity(LCOE)of the present commercial CSP plants,the next generation CSP technology with higher process temperature and energy efficiency is being developed.The TES system in the next generation CSP plants works with new TES materials at higher temperatures(>565℃)compared to that with the commercial nitrate salt mixtures.This paper reviews recent progressin research and development of the next generation CSP and TES technology.Emphasis is given on theadvanced'TES technology based on molten chloride salt mixtures such as MgCl_(2)/NaCl/KCl which hassimilar thermo-physical properties as the commercial nitrate salt mixtures,higher thermal stability(>800℃),and lower costs(<0.35USD·kg^(-1)).Recent progress in the selection/optimization of chloridesalts,determination of molten chloride salt properties,and corrosion control of construction materials(eg.,alloys)in molten chlorides is reviewed.

Assessment of Hybrid Concentrated Solar Power-Biomass Plant Generation Potential in Sahel: Case Study of Senegal

Concentrating Solar Power (CSP) is non-existent in Sahel. Such a situation arises from the high investment costs required by these energy infrastructures and from a lack of information on the identification of suitable sites to accommodate them. Conversely, CSP-biomass plants due to lower investment may be an option for CSP penetration in Sahel where Direct Normal Irradiation (DNI) is between 1400 kWh/m2/year and 2000 kWh/m2/year and significant biomass potential. This work presents the results of an identification of suitable sites for hybrid CSP-Biomass in the Sahel, case study of Senegal, taking into account the Direct Normal Irradiation, the availability of water, space and biomass potential. The identified sites have a DNI > 1600 kWh/m2/year. The biogas production capacity is equivalent to 5,096,563 m3/year. The quantity of Typha Australis, invasive plant in Senegal river valley available is estimated at more than 3 million tons. The capacity of electrical energy in this zone is estimated at 6.89 GWe for an installation surface estimated at 275.61 km2. The establishment of CSP/hybrid plants can also contribute to combat the proliferation of Typha Australis.

Multi-aiming Strategy Design for Quadruple Prism Shaped Central Receiver in Solar Power Tower System

For solar power tower technology, the improvement of interception efficiency of heliostat field and the extension of central receiver's life time are two technical difficulties. To the receiver, higher interception efficiency means more thermal shocks and stronger stresses of high temperatures mainly contribute to the reduction of receiver's life time. To address these problems,a semi-random distribution strategy is proposed to select the best aiming point of the heliostat, and the distribution of onedimensional array arranged on the centerline of the receiver is carried out for further optimization. It is shown by simulation that through our optimization the temperature distribution on the receiver surface becomes much more uniform while maintaining acceptable interception efficiency.

基于FCM-LSTM的光热发电出力短期预测

对光热电站的出力进行短期预测,可以有效应对太阳能随机性和波动性带来的影响,为电网调度做好准备.该文以青海某光热电站为例,首先使用模糊C均值聚类算法对预处理后的实验数据进行分类,然后通过分析不同聚类类型下出力和气象数据中各因子间的关联程度,充分挖掘出数据间的关系,确定不同类型预测模型的输入变量,进而构建出不同类别下的长短期记忆神经网络预测模型.结果表明,与传统长短期记忆神经网络模型、BP神经网络模型、支持向量机模型和随机森林模型的预测结果相比,基于模糊C均值聚类的长短期记忆神经网络预测模型效果良好,大幅减少了预测误差,验证了该预测模型的有效性.

基于三端柔性直流的光热储能站与新能源场站功率协同控制策略

新能源基地大多经传统交流方式接入高压交流或直流外送通道,为解决大规模新能源经交流接入方式下并网容量小、损耗大,以及功率波动对电网稳定性影响等问题,构建了一个基于柔性直流输电并网的风电和光伏、光热储能及电网三端柔性直流系统。基于直流电压-有功功率特性,提出一种适用于该系统的站间协调控制策略,根据柔性直流输电系统的直流电压波动情况,调整光热储能机组的出力,以平抑风、光功率波动,降低其对电网的影响。针对光热储能侧换流站,采用直流电压裕度下垂混合控制策略,通过控制器参数配置,抑制控制模式切换过程中的暂态过电压,提高系统响应速度。最后,在PSCAD/EMTDC中搭建三端柔性直流系统仿真模型,验证所提控制策略的有效性。

碳交易机制下园区综合能源系统优化调度

为抑制园区综合能源系统的碳排放,优化系统运行成本,提出一种以系统运行总成本最小为目标、平衡经济性和低碳性的园区综合能源系统优化调度策略。首先将阶梯式碳交易机制引入综合能源系统,然后在能源供给侧利用光热电站促进光能实现削峰填谷,在需求侧通过需求响应减少电、热能的使用成本,最后运用CPLEX进行求解,并对多个优化调度方案进行对比分析。结果表明,所提方案在有效控制系统运行成本的同时,碳排放量也得到降低,有助于园区综合能源系统实现“双碳”目标。

光热电站主机直接空冷系统优化探讨

光热发电是一种比较有发展前景的可再生能源发电形式,具有良好的储能和调峰能力。受制于水资源条件,目前我国光热电站的主机冷却系统多采用直接空冷系统。直接空冷系统配置对机组经济性和盈利能力均会产生较大影响。在总结和分析光热电站投资构成及运行特点的前提下,依托某案例工程进行直接空冷系统优化计算和分析。对光热电站直接空冷系统气象数据选取与处理、以及电价敏感性分析进行初步探讨。由于上网电价及成本电价普遍较高,与常规火电厂直接空冷系统相比较,光热电站直接空冷系统配置倾向于初始温差(ITD)值较低、风速较小、空冷凝汽器面积较大的方案。

含CSP电站的风光火储联合外送系统优化配置

为解决中国西北地区的新能源消纳问题,提出一种含CSP电站的风光火储联合外送系统优化配置方法。首先,根据风光火储的互补特性建立含CSP电站的风光火储联合外送系统的典型架构,并分析其工作机制;其次,结合拉丁超立方抽样以及基于时序自相关和互相关的时序重构、时序组合和场景择优,生成考虑时序自相关和互相关性的随机场景集;接着,以计及碳排放成本的系统收益和系统新能源消纳能力最优为多目标,构建含CSP电站的风光火储联合外送系统多目标优化配置模型,并通过增广ε-约束法结合商用软件CPLEX进行求解;最后,以西北某地区2025年电网规划数据构造的算例进行仿真,验证了该配置方法能有效提高系统收益,促进风光消纳,提高系统电力送出能力。

Thermo-Economic Optimization of Solar Thermal Devices by Coherent Integration of Technologies

Radiation is a form of energy where the angular variable of the direction of its photons has a primary importance, particularly for radiation concentration processes, which are essential tools to reach high temperatures from radiation beams (as the solar ones) with moderate intensities. Solar radiation cannot be used directly to feed thermodynamic cycles, and optical concentration must be applied to that goal. In general, reflection from mirrors is preferred to refraction by lenses in this case, because they have less optical aberrations. Concentration conveys very high temperatures in the receiver. However, the higher the temperature, the lower the efficiency of the solar thermal apparatus. Besides that, economy also suffers quite a lot when going to very high concentration factors, which is one of the main burdens in the development of Solar Thermal Energy. A new configuration of solar radiation concentrator is presented. It includes a salient innovation in the way the mirrors are given the right curvature by mechanical forces. Those mirrors are originally flat and do not need any special thermal treatment for this purpose. The whole device concept has been guided by the principle of thermoeconomic coherence, which requires similar efforts in all degrees of freedom that have strong influence in the performance and cost of the system. The paper shows the decision tree that has oriented the project, following the principle of equilibrium in efforts, which leads to a design window of moderate values in the main variables. The prototype of this new configuration has already been built, and the first stage of research is considered to be finished, because the prototype has shown excellent conditions to include selected (fitting) technologies at a very low cost.

计及多重不确定性及光热电站参与的区域综合能源系统配置与运行联合优化

针对含光热电站参与的多能耦合区域综合能源系统,考虑了系统中风光出力、光热电站中的储热装置出力、负荷、购能价格的不确定性,提出了一种基于多元宇宙算法-区间线性规划的双层优化配置方法。上层以运行年限内总收益最大为目标进行设备选型和容量配置,下层以运行净收益最大为目标优化各设备出力,从而获得系统的最佳配置与运行方案。算例结果表明,光热电站的参与可以增加系统的协调优化能力,且与传统算法相比,采用多元宇宙算法对模型进行求解,收敛速度更快,考虑多重不确定因素的优化配置能够使得系统的净收益更加稳定,提高系统的总收益。

考虑氢储供能时序的综合能源系统三阶段调度

为提高可再生能源的消纳水平,分析可调度能源价格对可再生能源消纳的影响,提出从源荷侧双角度结合的方法。源侧将机组分为可调度能源和可再生能源机组两部分,同时考虑光热电站、热电联产机组联合运行;荷侧考虑居民负荷和工业负荷,将工业负荷中氢储参与电能调度。结合电能三阶段调度,建立了考虑氢储供能时序的综合能源系统三阶段调度模型。模型以运行成本最低为目标函数,调用Matlab中SCIP求解器求解,结果表明,模型能够有效提升系统灵活性,促进可再生能源消纳,同时显著提高系统运行经济性。

碳交易机制下光热电站参与的综合能源系统配置与优化运行研究

对于“双碳”背景下光热电站参与的综合能源系统,建立了碳交易机制下考虑源侧出力和荷侧需求不确定性的多能耦合区域综合能源系统两阶段鲁棒优化配置与优化运行模型。模型中针对不确定性调节参数的设定,使运行方案更具灵活性。然后,基于列与约束生成算法和拉格朗日对偶法,将原问题分解为主问题和子问题迭代求解。最后,通过仿真算例验证了所提方法。结果表明本方法能有效减少不确定性因素导致系统容量配置波动大的问题,并能够降低综合调度成本;同时光热电站的参与运行使得系统能够兼顾低碳性和经济性。

考虑光热光伏混合电站内外双重电压安全的两阶段无功优化控制

针对实际运行的大规模光热光伏混合电站并网后面临的“内忧外患”电压问题,既受电站内部节点电压状态的影响,也受外部电网系统静态电压稳定状态的影响,提出一种考虑光热光伏混合电站内外双重电压安全的两阶段无功优化控制方法。首先,通过静态电压稳定裕度、节点电压均衡度和无功储备裕度3种指标表征混合电站电压安全状态。然后,结合小时级长时间尺度的光伏出力预测信息,在第I阶段实施有载变压器和电容器慢速调整。针对分钟级短时间尺度内的光伏出力波动,以混合电站内的光伏发电单元、光热发电单元和静止同步补偿器为第II阶段的优化控制对象,实现快速精细化电压调节。所提方法能有效避免全站设备频繁参与优化调整,从而提高控制效率。最后,通过测试系统验证分析结果表明:通过两阶段无功控制协调,所提方法能够抑制光伏出力的波动冲击,有效降低站内电压安全越限和失稳风险。

含光热电站的热-电系统供暖期优化调度

为解决西北地区热电联产机组“以热定电”特性导致供暖期产生弃风的问题,提出一种含光热电站的热电联供系统优化调度策略。该模型将含储热的光热电站与电加热装置联合进行辅助供热,同时考虑能量损耗的影响,以系统综合成本最小、弃风率最低为目标,制订最优日前调度计划。模型对光热电站供热潜力进行深度开发,减弱了常规热电联产机组热电耦合程度,大大提高了风电消纳水平。最后利用西北某地区实际数据进行算例分析,验证模型有效性。结果表明,所提策略在促进风电消纳的同时降低系统综合成本。

计及阶梯式碳交易机制的海岛综合能源优化调度

针对以柴油发电为主的传统海岛供电模式,存在污染环境、成本高且不易运输等问题,提出一种含碳交易机制的海岛综合能源优化运行策略。在以净收益最大为目标的同时,考虑阶梯式碳交易机制、新能源消纳、系统运行约束,构建了一种含阶梯式碳交易的光热储能配合风电制氢的日前综合能源优化调度模型。最后,通过cplex求解模型并对各类优化调度方案进行对比。结果表明,本文所提方案能有效提高系统收益及新能源消纳率,具有有效性和经济性。

Concentrated solar energy——the path for efficient thermal conversion to power and fuels

Concentrated solar energy provides an unlimited clean source of high-temperature process heat. It can be therefore used for power generation by driving heat engines, as well as for fuel production by driving endothermic chemical transformations (1)Currently, the main optical configurations to concentrate the direct(beam) solar radiation at large scale are the line-focussing parabolic trough and linear Fresnel systems, and the point-focussing solar tower and dish systems.

物探队在聚光太阳能热发电厂作业的风险分析和对策

物探队的施工作业现场往往是沙漠、戈壁等太阳能储备丰富的地方,而聚光太阳能热发电厂也一般建设在这种环境下,经过大规模建设,占地面积非常大。如果物探队作业现场有聚光太阳能热发电厂,倘若进行炮点偏移的话,将会对物探数据采集的质量和生产效益带来很大影响。如果进入聚光太阳能热发电厂进行物探施工作业,则会面临许多新风险和挑战。对物探队进入聚光太阳能热发电厂施工作业进行了风险分析,并针对主要风险提出了对策和风险控制措施。

蓄热技术在聚焦式太阳能热发电系统中的应用现状

从了解聚焦式太阳能热发电(CSP)的发展背景出发,综述了CSP系统中的蓄热技术的应用现状与发展方向,对各种蓄热技术进行了比较,并简要介绍了我国目前技术发展的现状,同时指出经济型的蓄热系统设计是CSP系统成功走向市场化的关键技术,双罐熔融盐直接蓄热塔式系统将是我国发展CSP技术努力的方向。

光热发电机组聚合模型及其在电力系统运行模拟中的应用

光热发电不仅提供了一种大规模利用太阳能的方式,还具备良好的调峰能力,能为构建可再生能源主导的电力系统提供有力支撑。由于组成结构和运行特性的特殊性,光热机组在建模中面临着所需变量多、约束复杂的问题。考虑到其单机容量较小,大规模光热并网后将显著提升运行模拟问题的规模和复杂度,增大模型求解难度,给电力系统运行模拟和优化规划带来挑战。针对上述问题,提出一种光热聚合建模方法,将多台机组聚合成一台等效机组,从而减小问题规模、加速模型求解。基于改编IEEE-RTS79的算例分析表明该方法正确、有效,不仅加速效果显著,而且计算误差较小。所提出的方法能为含大规模光热电力系统运行模拟及规划研究提供有力的分析工具。

明确太阳能热发电战略定位促进技术发展

太阳能热发电技术具有安全性高、电力品质高、储能规模大、可双向连接电网的优势,在"碳达峰、碳中和"战略中具有不可替代的地位,在构建以新能源为主体的新型电力系统中将发挥中坚作用。通过近20年的发展,我国太阳能热发电产业成熟度高,产业链完整,国内已投运项目的设备国产化率超过90%,具备大规模应用发展的条件。对太阳能热发电科技引领突破,产业规模发展大幅度降低成本,与光伏风电打捆参与电力市场促进太阳能热发电产业发展等方面进行分析,并提出了建议。