Analysis of behaviour of computational model to evaluate performance of heat pipe containing nanofluids

含纳米流体热管性能计算模型的分析

Application of nanofluids in heat pipes usually presents satisfactory experimental results regarding a thermal resistance reduction of the heat pipe.However,the existing computational studies connecting heat pipes and nanofluids lack a deeper discussion regarding the validity of the models currently used for representing the behaviour of a nanofluid in a heat pipe,particularly for unusual base fluids and nanoparticles such as carbon nanotubes or ethylene glycol.Thus,this comparative study presents the results of a set of computational simulations using pre-established equations for modelling a nanofluid in a heat pipe with experimental data from the literature.The results show agreement with the expected behaviour qualitatively and the presented maximum variations between 1.5% and 23.9% in comparison to the experimentally measured average temperatures.Also,the experimentally obtained temperature distribution of a heat pipe could not be reached numerically only with the use of adequate thermal properties,indicating that the boiling phenomenon is more complex than the current model used for computational simulations.Moreover,the existence of an optimal particle volume fraction for using nanofluids in this application could be observed by combining different properties models.

将纳米流体应用在热管中进行热阻降低实验,可以得到理想的实验结果。然而,为了表征纳米流体在热管中的行为,目前所建立的热管和纳米流体的研究模型尚缺少深入讨论,特别是对于基础流体和纳米颗粒如碳纳米管或乙二醇的研究。因此,本研究先建立热管中纳米流体的流动方程,根据文献中热管的数据进行模拟。结果表明,实验测得的平均温度与预测结果有定性的一致性,误差在1.5%和23.9%之间。此外,实验得到的热管温度分布不能仅通过适当的热性能数值计算得到,这也表明沸腾现象比现有的应用模型更复杂。通过结合不同的性能模型,可以观察到纳米流体在此应用中存在最优的颗粒体积分数。