新型低熔点熔盐黏度的实验研究

熔盐因其具有广泛的使用温度范围,低蒸气压,大热容量,低黏度,良好的稳定性,低成本等诸多特性已成为聚光太阳能热发电中颇有潜力的传热蓄热介质。准确的熔盐热物性对于太阳能发电过程中介质的传热蓄热性能有重要影响。其中熔盐黏度作为重要的热物性之一,对于提高传热效率和降低流动阻力具有决定作用。本文利用研制的高温黏度测量仪对水和HITEC盐的黏度温度特性进行了实验研究,实验结果与文献数据具有较好的一致性,证明了该高温熔盐黏度仪的可靠性。为了降低混合熔盐的熔点,改进其热物性能,本文对Solar Salt进行改性研究,得到两种新型低熔点混合熔盐,并测定得到了黏度温度特性曲线。结果表明,改性后的高温熔融盐黏度有所降低,有利于降低太阳能热发电熔盐传热管路系统的阻力和成本。

Experimental Study of Viscosity of New Kind of Molten Salt With Low Melting Point

Molten salt,with wide using temperature range,low vapor pressure,large heat capacity, low viscosity,good thermal stability,low cost and so on,has become recognized as a considerable regenerative potential of the heat transfer medium for solar thermal power generation.Accurate thermal property data of molten salt has a major impact on heat transfer and storage performance of medium used in solar thermal power generation.Viscosity of molten salt,as an important one of thermal properties,has a decisive role on improving heat transfer efficiency and reducing flow resistance.In this paper,viscosity-temperature characteristics of water and HITEC were measured by using developed high-temperature viscometer,and the results were agreement with literature data to prove the reliability of this high-temperature molten salt viscometer.In order to reduce the melting point of mixed molten salt and improve their thermal properties,based on Solar Salt,two new kinds of molten salts with low melting point were obtained through modification, whose viscosity-temperature characteristics were studied further.The results show that viscosity of modified high-temperature molten salt decreased at a certain degree,that is helpful to reduce the resistance of molten salt heat transfer system and cost of solar thermal power generation.