Sang Lixia, Ai Wenming, Liu Tai, Wu Yuting, Ma Chongfang
Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Ministry of Education, Key Laboratory of Heat Transfer and Energy Conservation Beijing Municipality, Department of Energy Science and Engineering, College of Environmental and Energy Engineering, Beijing University of Technology Beijing 100124 China
RSC Adv. 2019 Feb 12;9(10):5288-5294. doi: 10.1039/c8ra10318f. eCollection 2019 Feb 11.
Ternary carbonate nanofluids have proven to be a promising high temperature thermal energy storage and transfer medium for solar thermal power. For the ternary carbonate KCO-LiCO-NaCO (4 : 4 : 2, mass ratio) with SiO nanoparticles prepared using a two-step solution method, the enhancement of the specific heat capacity was up to 113.7% at 540 °C compared to the ternary carbonate prepared by a direct mixing method. The present work aims to give insights into the marked enhancement of specific heat capacity. The effect of evaporation temperature on the nanostructures formed in ternary carbonate nanofluids is discussed for the enhancement of specific heat capacity. More importantly, based on an analysis of inductively coupled plasma atomic emission spectrometry, it is revealed that the composition ratio of the ternary carbonate, which can influence its specific heat capacity, was changed during the evaporation process in an electrothermal drier. Besides a difference in the solubility of the carbonates in water, it is demonstrated that the heating mode can affect the composition ratio of mixed molten salts.
三元碳酸盐纳米流体已被证明是一种用于太阳能热发电的、很有前景的高温热能储存和传输介质。对于采用两步溶液法制备的含有SiO₂纳米颗粒的三元碳酸盐K₂CO₃-Li₂CO₃-Na₂CO₃（质量比4∶4∶2），与通过直接混合法制备的三元碳酸盐相比，在540℃时其比热容提高了113.7%。本工作旨在深入了解比热容的显著提高。讨论了蒸发温度对三元碳酸盐纳米流体中形成的纳米结构的影响，以提高比热容。更重要的是，基于电感耦合等离子体原子发射光谱分析表明，在电热干燥器的蒸发过程中，会影响其比热容的三元碳酸盐的组成比例发生了变化。除了碳酸盐在水中溶解度的差异外，还证明了加热方式会影响混合熔盐的组成比例。
