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首页> 外文期刊>International Journal of Heat and Mass Transfer >R134a and R1234ze(E) liquid and flow boiling heat transfer in a high porosity copper foam
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R134a and R1234ze(E) liquid and flow boiling heat transfer in a high porosity copper foam

机译：高孔隙率铜泡沫中的R134a和R1234ze（E）液体和流动沸腾传热

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摘要

Heat dissipation is one of the most important issues for the reliability of electronics equipment. Boiling can be a very efficient heat transfer mechanism, thus it can be used to maintain the junction temperature of electronics equipment at values compatible with the technology using efficient and compact heat sinks. On the other hand, the environmental issues associated with the use of synthetic refrigerants call for a continuous improvement in technical solutions. Recently, new low-GWP refrigerants, in particular R1234ze(E), have been proposed as possible alternatives of the more traditional R134a. Besides, cellular structured materials both stochastic and periodic, particularly open cell metal foams, have been suggested as possible enhanced surfaces to lower electronics temperatures at high heat fluxes. Until now, most of the research on metal foams regards only single phase flow, whereas two phase flow is still almost unexplored. This paper presents an experimental study on the heat transfer of R134a and R1234ze(E) during single phase liquid and flow boiling inside a 5 PPI copper foam. The experimental measurements were carried out by imposing two different heat fluxes: 50 and 100 kWm~(-2), at constant saturation temperature of 30 ℃; the refrigerant mass velocity was varied between 50 and 200 kg m~(-2) s~(-1) while the vapor quality varied from 0.2 to 0.95. As a result, the effects of the refrigerant mass flow rate, heat flux, and vapor quality on the heat transfer coefficient, dryout phenomenon, and pressure drop are investigated. Furthermore, the flow boiling heat transfer was observed using a high speed video camera allowing for a detailed analysis of the experimental results.
机译：散热是影响电子设备可靠性的最重要问题之一。沸腾是一种非常有效的传热机制，因此可以用来将电子设备的结温保持在与使用高效紧凑的散热器的技术兼容的值。另一方面，与使用合成制冷剂相关的环境问题要求技术解决方案的不断改进。最近，已经提出了新的低全球升温潜能值的制冷剂，特别是R1234ze（E），可以作为更传统的R134a的替代品。此外，已经提出了随机的和周期性的多孔结构材料，特别是开孔金属泡沫，作为可能的增强表面，以降低高热通量下的电子温度。到目前为止，有关金属泡沫的大多数研究都只涉及单相流，而关于两相流的研究仍很少。本文介绍了在5 PPI铜泡沫内单相液体和流动沸腾过程中R134a和R1234ze（E）的传热实验。通过在恒定的30℃饱和温度下施加50和100 kWm〜（-2）两个不同的热通量来进行实验测量。制冷剂质量速度在50至200 kg m〜（-2）s〜（-1）之间变化，而蒸汽质量在0.2至0.95之间变化。结果，研究了制冷剂质量流量，热通量和蒸气质量对传热系数，变干现象和压降的影响。此外，使用高速摄像机观察了流动沸腾的热传递，从而可以对实验结果进行详细分析。

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  • 作者

    Simone Mancin; Andrea Diani; Luca Doretti; Luisa Rossetto;

  • 作者单位

    Dipartimento di Ingegneria Industrial, Universita degli Studi di Padova, Via Venezia 1, 35131 Padova, Italy;

    Dipartimento di Ingegneria Industrial, Universita degli Studi di Padova, Via Venezia 1, 35131 Padova, Italy;

    Dipartimento di Ingegneria Civile, Edile e Ambientale, Universita degli Studi di Padova, Via Marzolo 9, 35131 Padova, Italy;

    Dipartimento di Ingegneria Industrial, Universita degli Studi di Padova, Via Venezia 1, 35131 Padova, Italy;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    R134a; R1234ze(E); Flow boiling; Copper foam; Flow visualization;

    机译：R134a;R1234ze（E）;流沸腾;泡沫铜;流程可视化;

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