利用可见-近红外吸收光谱技术对高温熔融盐蓄热特性研究

项目名称： 利用可见-近红外吸收光谱技术对高温熔融盐蓄热特性研究

项目编号： No.51506214

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 苏涛

作者单位： 中国科学院上海应用物理研究所

项目金额： 21万元

中文摘要： 太阳能热发电是非常有发展前景的可再生能源发电方式，熔盐直接吸收太阳能蓄热是关键技术之一。熔融盐由于具有传热性能好、液态工作温度范围宽等优点，成为太阳能热发电系统中重要的传蓄热介质。已有研究表明，熔融盐中添加少量添加剂可以显著提高其蓄热性能。本项目以传统太阳能传蓄热介质HTS（40%NaNO2-7%NaNO3-53%KNO3）为研究对象，测定其在可见-近红外波段的吸收光谱，构建吸收光谱与熔融盐蓄热特性的相关性；同时采用密度泛函理论计算方法预测多种添加剂在熔融盐中的增色吸收光谱；结合新体系熔盐吸收光谱和关键热物性参数（比热、导热系数等）测定，探索添加剂种类、添加量等与熔盐蓄热特性变化的关系。本研究利用在标准仪器基础上构建的高温熔融盐吸收光谱实验平台，建立了一种评价熔盐蓄热特性的方法，可以为太阳能热发电站设计提供必要的参数，通过添加剂的方式提高熔盐蓄热特性，可以为降低太阳能热发电成本提供依据。

中文关键词： 高温熔融盐；蓄热特性；可见-近红外吸收光谱；熔盐热物性；DFT计算

英文摘要： Concentrating Solar Power (CSP) is one of most promising power generation by renewable energy, in which thermal storage by molten salts directly absorbing solar energy is one of key techniques. Molten salts become the important heat-transfer and thermal storage media in the CSP system due to their excellent heat-transfer performance, low work pressure, wide work temperature range etc. Previously, many reports indicate that small amount of additives into molten salts can enormously enhance thermal storage performance. In this project, the visible-near-infrared absorption spectra of HTS (40%NaNO2-7%NaNO3-53%KNO3) that is widely used in CSP system is measured to construct the correlation with molten salts thermal storage characteristic, simultaneously, density functional theory (DFT) is employed to predict absorption spectra of additives in molten salts; in addition, the relation of heat-storage characteristic with species and quality of additives is explored by combination of absorption spectra of new molten salts system and key thermo-physical properties. The experimental platform of high-temperature molten salts absorption spectra is established on the basis of standard instrument, of which a method is developed to appraise molten salts thermal storage characteristics by use. It has essential implications for this project, the determination of heat-storage characteristic can supply essential parameters for CSP design, enhancement of thermal storage characteristic by additives into molten salts can tremendously reduce the cost of CSP construction.

英文关键词： molten salt;thermal storage characteristics;visible-near-infrared spectroscopy;thermo-physical properites;DFT calculation