Fachbereich Mathematik und Naturwissenschaften, Bergische Universität, Wuppertal, D-42097, Germany.
Nanoscale Res Lett. 2016 Dec;11(1):88. doi: 10.1186/s11671-015-1188-5. Epub 2016 Feb 13.
Molten salts are used as heat transfer fluids and for short-term heat energy storage in solar power plants. Experiments show that the specific heat capacity of the base salt may be significantly enhanced by adding small amounts of certain nanoparticles. This effect, which is technically interesting and economically important, is not yet understood. This paper presents a critical discussion of the existing attendant experimental literature and the phenomenological models put forward thus far. A common assumption, the existence of nanolayers surrounding the nanoparticles, which are thought to be the source of, in some cases, the large increase of a nanofluid's specific heat capacity is criticized and a different model is proposed. The model assumes that the influence of the nanoparticles in the surrounding liquid is of long range. The attendant long-range interfacial layers may interact with each other upon increase of nanoparticle concentration. This can explain the specific heat maximum observed by different groups, for which no other theoretical explanation appears to exist.
熔盐被用作太阳能发电厂的传热流体和短期热能储存介质。实验表明，通过添加少量特定纳米粒子，可以显著提高基础盐的比热容。这种效应在技术上很有趣，在经济上也很重要，但目前还没有得到很好的理解。本文对现有的相关实验文献和迄今为止提出的唯象模型进行了批判性讨论。一个常见的假设是纳米层围绕着纳米粒子，人们认为纳米粒子是纳米流体比热大幅增加的原因，这一假设受到了批评，并提出了一种不同的模型。该模型假设纳米粒子在周围液体中的影响具有长程性。随着纳米粒子浓度的增加，相邻的长程界面层可能会相互作用。这可以解释不同研究小组观察到的比热最大值，对于这种现象，目前似乎还没有其他理论解释。
