Analysis of supercritical CO2 cooling in macro- and micro-channels
Analysis of supercritical CO2 cooling in macro- and micro-channels
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DOI：
10.1016/j.ijrefrig.2008.01.010
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发表时间：
2008-12
期刊：
影响因子：
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通讯作者：
Lixin Cheng;G. Ribatski;J. Thome
中科院分区：
文献类型：
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作者：
Lixin Cheng;G. Ribatski;J. Thome
本文综合分析了超临界co2在宏观和微通道中的传热和压降实验数据及相关关系。首先讨论了超临界条件下co2的物理性质和输运性质及其对传热和压降的影响。其次，回顾了超临界co2冷却的传热和压降实验研究，并尽可能详细地比较和分析了超临界co2冷却的传热和压降相关性。此外，注意到缺乏使用这些研究中发表的数据所需的所有相关实验细节，并就如何在未来适当地减少和呈现超临界二氧化碳实验数据提出了意见。此外，油对超临界co2的传热和压降的影响显著降低了前者，增加了后者。将实验数据与选择的传热相关性进行比较表明，Fang等[2001b]。气体冷却器的建模与分析。ASHRAE学报，107(1)，4-13]相关性给出了最接近实验数据的值，但仍不能令人满意。通过对比分析，建议今后在精确数据库的基础上，进一步努力开发超临界co2冷却的良好换热方法。为了实现这一目标，需要在更大的测试参数范围内进行更仔细的实验，以满足实际应用的要求。此外，四项实验研究表明，Blasius方程适用于近超临界区域的co2冷却。由于一些实验数据与其他实验数据差异很大，因此还需要更仔细的实验数据来进一步验证这一结论。
A comprehensive analysis of heat transfer and pressure drop experimental data and correlations for supercritical CO2cooling in macro- and micro-channels is presented in this article. First, the physical and transport properties of CO2at supercritical conditions are discussed and then their influence on heat transfer and pressure drops. Next, a review of experimental studies on heat transfer and pressure drops of supercritical CO2cooling is provided and detailed comparisons and analysis relative to the available heat transfer and pressure drop correlations for supercritical CO2cooling were done where possible. Furthermore, noting the lack of all pertinent experimental details required to use the data published in many of these studies, comments are given on how to reduce and present supercritical CO2experimental data properly in the future. In addition, the effect of oil on heat transfer and pressure drops for supercritical CO2is shown to significantly decrease the former and to increase the latter. Comparison of experimental data to a selection of heat transfer correlations shows that the Fang et al. [2001b. Modeling and analysis of gas coolers. ASHRAE Trans. 107 (1), 4–13] correlation gives the closest values to the experimental data but is still not satisfactory. According to the comparison and analysis, it is recommended that further efforts be made to develop good heat transfer methods for supercritical CO2cooling based on accurate database in the future. To achieve this, more careful experiments should be done over a wide range of test parameters to meet the requirement in practical applications. In addition, four experimental studies show that the Blasius equation works well for CO2cooling in the near supercritical region. More careful experimental data are still needed to further validate this conclusion because some experimental data are much different from others.