Agromayor Roberto, Cabaleiro David, Pardinas Angel A, Vallejo Javier P, Fernandez-Seara Jose, Lugo Luis
Área de Máquinas y Motores Térmicos, Escola de Enxeñería Industrial, Universidade de Vigo, Vigo E-36310, Spain.
Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, Vigo E-36310, Spain.
Materials (Basel). 2016 Jun 8;9(6):455. doi: 10.3390/ma9060455.
The low thermal conductivity of fluids used in many industrial applications is one of the primary limitations in the development of more efficient heat transfer systems. A promising solution to this problem is the suspension of nanoparticles with high thermal conductivities in a base fluid. These suspensions, known as nanofluids, have great potential for enhancing heat transfer. The heat transfer enhancement of sulfonic acid-functionalized graphene nanoplatelet water-based nanofluids is addressed in this work. A new experimental setup was designed for this purpose. Convection coefficients, pressure drops, and thermophysical properties of various nanofluids at different concentrations were measured for several operational conditions and the results are compared with those of pure water. Enhancements in thermal conductivity and in convection heat transfer coefficient reach 12% (1 wt %) and 32% (0.5 wt %), respectively. New correlations capable of predicting the Nusselt number and the friction factor of this kind of nanofluid as a function of other dimensionless quantities are developed. In addition, thermal performance factors are obtained from the experimental convection coefficient and pressure drop data in order to assess the convenience of replacing the base fluid with designed nanofluids.
许多工业应用中使用的流体的低导热率是开发更高效传热系统的主要限制之一。解决这个问题的一个有前景的方法是在基础流体中悬浮具有高导热率的纳米颗粒。这些悬浮液，即所谓的纳米流体，在增强传热方面具有巨大潜力。本文探讨了磺酸功能化石墨烯纳米片水基纳米流体的传热增强问题。为此设计了一种新的实验装置。在几种操作条件下，测量了不同浓度的各种纳米流体的对流系数、压降和热物理性质，并将结果与纯水的结果进行了比较。导热率和对流换热系数的增强分别达到12%（1 wt%）和32%（0.5 wt%）。开发了能够预测这类纳米流体的努塞尔数和摩擦系数作为其他无量纲量函数的新关联式。此外，从实验对流系数和压降数据中获得热性能因子，以评估用设计的纳米流体替代基础流体的便利性。
