A NaNO3-KNO3-Mg(NO3)2 Molten Nitrate Salt Used for Solar Thermal Power Generation
DU Baoqiang1,2, WANG Huaiyou1,3, LI Jinli1,3, ZHAO Youjing1,3, YANG Hongjun1,3, ZHONG Yuan1,3, WANG Min1,3
1 Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008; 2 University of Chinese Academy of Sciences, Beijing 100049; 3 Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008
摘要 Solar Salt(60%NaNO3-40%KNO3)熔盐作为传蓄热介质,在太阳能光热发电领域应用广泛。以Solar Salt熔盐为基础,采用熔融共混法,通过添加Mg(NO3)2·6H2O制备了低熔点NaNO3-KNO3-Mg(NO3)2三元熔盐(NKM熔盐),优化了制备工艺,获得了最佳工艺参数及条件,获得了三元熔盐热物性变化规律。通过热物性分析,确定NKM熔盐配比为49.5%NaNO3-33%KNO3-17.5%Mg(NO3)2。与Solar Salt和HTS(53%KNO3-40%NaNO2-7%NaNO3)熔盐相比,NKM熔盐具有较低的熔点和良好的温度使用范围,黏度较小,储热性和导热性良好,适合作为中温储能材料应用于光热发电。
Abstract: Solar Salt (60%NaNO3-40%KNO3) is widely used in solar thermal power generation as heat storage medium. NaNO3-KNO3-Mg(NO3)2 (NKM) ternary molten salt was obtained in this work through adding magnesium nitrate in Solar Salt molten salt, and a subsequent melt-blending process. The process parameters and conditions were optimized, and thermophysical properties of NKM ternary molten salt were obtained. The optimized composition of NKM ternary molten salt was 49.5%NaNO3-33%KNO3-17.5%Mg(NO3)2. Compared with HTS (53%KNO3-40%NaNO2-7%NaNO3) and Solar Salt, NKM ternary molten salt showed lower melting point and viscosity, higher density, better heat capacity and thermal conductivity, which indicated an application prospect as a promising candidate of medium temperature energy storage material for solar thermal power generation.
杜宝强, 王怀有, 李锦丽, 赵有璟, 杨红军, 钟远, 王敏. 面向太阳能光热发电的NaNO3-KNO3-Mg(NO3)2三元硝酸熔盐*[J]. 《材料导报》期刊社, 2017, 31(18): 1-4.
DU Baoqiang, WANG Huaiyou, LI Jinli, ZHAO Youjing, YANG Hongjun, ZHONG Yuan, WANG Min. A NaNO3-KNO3-Mg(NO3)2 Molten Nitrate Salt Used for Solar Thermal Power Generation. Materials Reports, 2017, 31(18): 1-4.
1 Price H. Advances in parabolic trough solar power technology[J]. Sol Energy Eng, 2002,124(2):109. 2 Zhang Z M, Wang G H, Gao H. Chinese regenerative energy deve-lopment strategy and policy study[J]. Rev Econ Res, 2004(84):26(in Chinese). 张正敏,王革华,高虎. 中国可再生能源发展战略与政策研究[J]. 经济研究参考,2004(84):26. 3 Wu Y T, Wang T, Ma C F, et al. Preparation and experimental study of binary nitrate salts[J]. Acta Energ Sol Sin, 2012,33(1): 148(in Chinese). 吴玉庭,王涛,马重芳,等. 二元混合硝酸盐的配制及性能[J]. 太阳能学报,2012,33(1):148. 4 Zhang H T, Zhao Y J, Li J L, et al. Preparation and thermal sto-rage properties of high-temperature molten nitrate salts[J]. Mater Sci Forum, 2015,814(47):60. 5 Kearney D,Kell B Y. Assessment of a molten heat transfer fluid in a parabolic trough solar field[J]. Sol Energy Eng, 2003,125(1):170. 6 于建国,宋兴福,潘惠琴. LiNO3-KNO3-NaNO3-NaNO2混合熔盐及制备方法:中国, 1263924A [P]. 2000-08. 7 Takahashi Y, Sakamoto R, Kamimoto M. Heat capacities and latent heats of LiNO3,NaNO3,KNO3[J]. Int J Thermophys, 1988, 9(6):1081. 8 Wang T, Ren N, Wu Y T, et al. Exploitation and experimental study of new mixed molten salt with low melting point[J]. Acta Energ Sol Sin, 2015,36(11):2605(in Chinese). 王涛,任楠,吴玉庭,等. 新型低熔点混合熔盐的开发和热物性测定[J]. 太阳能学报,2015,36(11):2605. 9 Wang T. Experimental study on thermal performance of mixed nitrate and carbonate salts[D]. Beijing:Beijing University of Techno-logy, 2009(in Chinese). 王涛. 混合硝酸及碳酸盐的热性能实验研究[D]. 北京: 北京工业大学,2009.