Purpose

This study aims to present the experimental and computational performance analysis in compact plate heat exchanger (PHE) using graphene oxide nanofluids at different concentrations and flow rate.

Design/methodology/approach

Field emission scanning electron microscope and X-ray diffraction were used to characterize graphene oxide nanoparticles. The nanofluid samples were prepared by varying volume concentration. Zeta potential test was done to check stability of samples. The thermophysical properties of samples have been experimentally measured. The experimental setup of PHE with 60° chevron angle has also been developed. The numerical analysis is done using computational fluid dynamics (CFD) model having similar geometry as of the actual plate. Distilled water at fixed temperature and flow rate is used in hot side tank. Nanofluid at fixed temperature with varying concentration and flow rate is used in cold side tank as coolant.

Findings

The numerical and experimental results were compared and found that both results were in good agreement. The results showed ∼13% improvement in thermal conductivity, ∼14% heat transfer rate (HTR), ∼9% in effectiveness and ∼10% in overall heat transfer coefficient at cost of pressure drop and pumping power using nanofluid. Exergy loss also decreased using nanofluid at optimum concentration of 1 Vol.%.

Originality/value

The CFD model can be significant to analyze temperature, pressure and flow distribution in heat exchanger which is impossible otherwise. This study gives ease to predict PHE performance with high accuracy without performing the experiment.

中文翻译：

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使用氧化石墨烯/水纳米流体的紧凑板式换热器性能的数值和实验分析

目的

本研究旨在展示使用不同浓度和流速的氧化石墨烯纳米流体的紧凑板式换热器 (PHE) 的实验和计算性能分析。

设计/方法/方法

场发射扫描电子显微镜和 X 射线衍射用于表征氧化石墨烯纳米粒子。通过改变体积浓度制备纳米流体样品。进行 Zeta 电位测试以检查样品的稳定性。样品的热物理性质已通过实验测量。还开发了具有 60° V 形角的 PHE 实验装置。数值分析是使用具有与实际板相似几何形状的计算流体动力学 (CFD) 模型完成的。热侧罐使用固定温度和流量的蒸馏水。在冷侧罐中使用不同浓度和流速的固定温度的纳米流体作为冷却剂。

发现

对数值和实验结果进行了比较，发现两者的结果非常吻合。结果表明，以使用纳米流体的压降和泵功率为代价，热导率提高了约 13%，传热率 (HTR) 提高了约 14%，效率提高了约 9%，总传热系数提高了约 10%。使用最佳浓度为 1 Vol.% 的纳米流体时，火用损失也减少了。

原创性/价值

CFD 模型对于分析换热器中的温度、压力和流量分布非常重要，而这在其他情况下是不可能的。这项研究可以轻松地以高精度预测 PHE 性能，而无需进行实验。