四元溴化熔盐密度特性实验研究

EXPERIMENTAL STUDY ON DENSITY PROPERTIES OF QUATERNARY BROMIDE SALTS

基于阿基米德法测量密度的原理改进测量高温熔盐密度的实验系统,并以LiNO_3和Solar Salt混合盐验证实验系统测量密度的可靠性,在此基础上以KBr、Li Br、Na Br、CaBr_2为基础配制出6种不同组分含量的混合溴化盐,测量6种混合溴化盐在不同温度下的密度,拟合得到混合溴化盐密度随温度变化的实验关联式。实验结果表明,Ca Br2含量对混合溴化盐密度大小起到关键作用,混合溴化盐密度随温度升高线性下降,与绝大部分已知熔体密度随温度变化规律一致。

Molten salt is an extremely promising medium for heat transfer and storage in Concentrating Solar Power system. Density is one of the most important factors directly determining capability of heat transfer and storage. An experimental system was improved to measure density of high temperature molten salt with Archimedes method. By measuring densities of LiNOz and Solar Ssalt, reliability of experimental system and method was validated. On this basis, six samples from KBr, LiBr, NaBr and CaBr2 were made up according to different mass ratios. Densities of samples were measured with the experimental system at 380-580 ℃ and fitted as functions of temperature. The results indicate that CaBr2 is key factor determining density values of quaternary bromide salts, and density values diminish linearly with increasing temperature in accord with density change of most known molten liquids.