抛物槽式太阳能集热器内合成油基纳米流体传热特性的数值模拟

对Al₂O₃-合成油纳米流体在槽式太阳能集热管内的传热特性进行流体动力学数值模拟，重点考察纳米流体导热系数模型的影响。通过与管内Nusselt数半经验模型的预测结果对比，表明使用考虑布朗运动的纳米流体导热系数模型可较好地预测集热管内传热特性。研究表明纳米颗粒与流体基液的相对运动具有促进集热管内传热的作用。最后，定量研究纳米颗粒添加量对提高基础流体平均传热系数的影响，显示纳米流体在太阳能集热器中具有巨大应用潜力。

Numerical Simulation of Heat Transfer of Synthetic Oil-based Nanofluids in a Parabolic Trough Solar Receiver

A computational fluid dynamics numerical simulation was performed on Al₂O₃-synthetic oil nanofluids to study heat transfer in a trough solar receiver. Different nanofluid thermal conductivity models were tried. Calculated Nusselt numbers were compared with results of semiempirical model models. It was found that the thermal conductivity model based on Brownian motion predicted heat transfer characteristics well. The relative motion between nanoparticles and base fluid was found important in enhancing heat transfer. Further volume fraction analysis shows that the nanoparticles improved significantly average heat transfer coefficient, which indicates that nanofluids have great potential in solar collector applications.