纳米二氧化硅强化四元溴化盐熔化潜热及热稳定性的实验研究

发布时间：2018-06-27 08:46

  本文选题：四元溴化盐 + 纳米SiO　； 参考：《太阳能学报》2017年10期

【摘要】：高温熔盐作为一种高效的传热和蓄热工质,其熔点的高低和熔化潜热的大小决定着熔盐的工作温度和相变蓄热能力。以化学纯Na Br、KBr、CaBr_2、LiBr为基盐,按照一定比例配制一种混合四元溴化盐。为改善该混合熔盐的性能,将纳米SiO_2以一定质量分数均匀加入混合溴化盐中,配制得到SiO_2纳米溴化盐。利用同步热分析仪对四元溴化盐和SiO_2纳米溴化盐的熔点和熔化潜热进行实验研究。实验结果表明纳米溴化盐的熔点随纳米SiO_2质量百分含量的增大而缓慢下降,下降幅度在2.5℃以内;熔化潜热随纳米SiO_2质量百分含量的增大呈近似直线规律升高,当纳米SiO_2含量达到1.5%时,该纳米SiO_2溴化盐的熔化潜热达到最大,较四元溴化盐升高了89.6%;纳米SiO_2的添加提高了四元溴化盐的分解温度及热稳定性。
[Abstract]:High temperature molten salt is an efficient heat transfer and heat storage medium. The melting point and latent heat of molten salt determine the working temperature and phase change heat storage ability of molten salt. A mixed quaternary bromine salt was prepared with chemical pure Na Br-KBr-CaBr-CaBr2LiBr as base salt. In order to improve the properties of the mixed molten salt, nano-SiO2 was added into the mixed bromine salt with a certain mass fraction and the Sio _ 2 nano-bromine salt was prepared. The melting point and melting latent heat of quaternary bromine salt and SiO2 nanocrystalline bromine salt were studied by synchronous thermal analyzer. The experimental results show that the melting point of nano-SiO2 decreases slowly with the increase of mass percent content of nano-SiO-2, and decreases within 2.5 鈩，

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