在圆柱面池沸腾传热强化与混合可湿性模式
Summary
池沸腾传热进行实验以观察对传热系数（HTC）混合可湿性图案的影响。调查的参数是联运的数量和改性可湿性表面的图案取向。
Abstract
In this study, pool-boiling heat-transfer experiments were performed to investigate the effect of the number of interlines and the orientation of the hybrid wettable pattern. Hybrid wettable patterns were produced by coating superhydrophilic SiO2 on a masked, hydrophobic, cylindrical copper surface. Using de-ionized (DI) water as the working fluid, pool-boiling heat-transfer studies were conducted on the different surface-treated copper cylinders of a 25-mm diameter and a 40-mm length. The experimental results showed that the number of interlines and the orientation of the hybrid wettable pattern influenced the wall superheat and the HTC. By increasing the number of interlines, the HTC was enhanced when compared to the plain surface. Images obtained from the charge-coupled device (CCD) camera indicated that more bubbles formed on the interlines as compared to other parts. The hybrid wettable pattern with the lowermost section being hydrophobic gave the best heat-transfer coefficient (HTC). The experimental results indicated that the bubble dynamics of the surface is an important factor that determines the nucleate boiling.
Introduction
甲提供在10-10 5瓦的范围内的冷却高热通量维持系统cm 2的需要/电子，国防，航空电子设备，和核装置发展的新兴领域。与空气传统冷却不足以用于这些应用由于两个自由和强制对流条件下低传热系数（HTC）。相位基于变更的冷却技术，例如池沸腾和流动沸腾，都不够好，10的顺序上除去高的热通量- 1000 W / cm 2的1。由于两相热传递过程是等温的，在冷却装置温度在其表面上几乎不变。由于沿表面的温度的变化可以忽略不计，该装置的热冲击可以被消除。然而，在沸腾传热的主要限制参数是临界热通量（CHF），这导致温度2的异常上升</sup>。
在过去的几十年中，广泛的研究已经进行了通过使用表面改性，纳米流体，和表面涂层3，4，5，6，7，8，9，10，11，以改善CHF。在各种方法中，表面涂层由于表面积大幅增加发现改善CHF的最佳方法。表面涂层通常增加鳍动作，孔隙率的影响，和表面润湿性12的热传递。表面润湿性起着沸腾传热一个显著的作用。以前的研究表明，在较低热通量的条件下，在疏水性表面显示出较好的HTC由于前期成核。然而，在较高热通量，所形成的气泡的分离是缓慢由于水朝向表面的低亲和力。这导致气泡聚结和导致较低的CHF 3。在另一方面，亲水性表面产生较高的CHF，因为所形成的气泡的快速拆卸的，但它在低的热通量使下部HTC，由于气泡成核13的延迟。
所述混合结构显示在沸腾传热所有热通量一个显着的提高，由于疏水性和亲水性14，15，16的组合效果。 Hsu 等人。通过涂覆超亲水的Si产生的异质可湿性表面纳米颗粒上的掩蔽铜表面上。它们通过改变涂层时间来实现不同的润湿性比。沸腾的发病早期出现异质表面上比在Homogeneous表面，其实质上减少了壁17过热。曹某等人。上的亲水性，疏水性，和异构的润湿表面进行核沸腾热传递的研究。将不均匀的润湿表面是由亲水性表面上的疏水性图案化的点。他们得到了较高的HTC的和非均相表面相比，亲水性表面一样瑞士法郎。在沸腾传热的改进直接取决于在表面上并在沸腾条件18的点的数量。
在这项研究中，使用浸涂技术的圆柱形的铜表面制作轴向混合可湿性图案。池沸腾传热研究，以确定联运的数目和混合可湿性图案的取向的影响。沸腾的热通量，HTC，和气泡动力学分析对于所有涂覆基材和我们与铜相比，衬底再。
Protocol
Representative Results
Discussion
The main goal of this investigation was to develop a pool-boiling heat sink for high heat dissipation applications, such as nuclear reactors, boilers, and heat pipes, by introducing the hybrid wettable surface, as described in the protocol section. These surfaces can produce better pool-boiling performances than homogeneous wettable surfaces (hydrophilic and hydrophobic). The improvement in the boiling heat-transfer performance is due to an increase in active nucleation sites and the easy detachment of the formed bubbles…
Disclosures
The authors have nothing to disclose.
Acknowledgements
The authors gratefully acknowledge funding support from the Ministry of Science and Technology, MOST (project numbers: MOST 104-2218-E-002 -004, MOST 105-2218-E-002-019, MOST 105-2221-E-002 -107 -MY3, MOST 102-2221-E-002 -133 -MY3, and MOST 102-2221-E-002 -088 -MY3).
Materials
| Deionized water | |||
| Silica nanopowder,40nm | UniRegion Bio-Tech | 60676860 | |
| Ethanol | ECHO Chemical co. Ltd | 64175 | |
| Hydrochloric acid | SHOWA Chemical co. Ltd. | 7647010 | |
| Tetraethoxysilane | SHOWA Chemical co. Ltd. | 78104 | |
| Acetone | UNI-ONWARD CORP. | 67641 | |
| Cartridge Heater | Chung Shun Heater & Instrument Co, Ltd. | ||
| Pyrex glass | Automotive Glass service , Taiwan | ||
| Ordinary toughened glass | Automotive Glass service , Taiwan | ||
| Thermal paste | Electrolube | EG-30 | |
| Insulation Tape | Chuan Chi Trading Co. Ltd | Kapton Tape | |
| Sandpaper | Chuan Chi Trading Co. Ltd | #2000 | |
| Heating furnace | Chung Chuan | Hong Sen HS-101 | |
| Electronic scales | A&D co. Ltd | GX400 | |
| Ultrasonic cleaner | Bransonic | Bransonic 3510 | |
| Magnet stirrer | Yellow line | MST D S1 | |
| Data logger | Yokogawa | MX-100 | |
| CCD camera | JVC | LY35862-001A | |
| Silicon paste | Permatex | 599BR | |
| Power supply | Gwinstek | GPR-20H50D | |
| Teflon tape | Chuan Chi Trading Co. Ltd | CS170000 | |
| Contact Angle Goniometer | Sindatek | Model 100SB | |
| Auxiliary Heater | Chuan Chi Trading Co. Ltd | ||
| T- type thermocouples | Chuan Chi Trading Co. Ltd | ||
| Reflux Condenser | Chuan Chi Trading Co. Ltd | ||
| Fiber glass | Professional Plastics, Taiwan |
References
- Putsch, G. Thermal challenges in the next generation of supercomputers. Proc. CoolCon MEECC Conference. , 1-83 (2005).
- Phan, H. T., Caney, N., Marty, P., Colasson, S., Gavillet, J. Surface wettability control by nanocoating: The effect on pool boiling heat transfer and nucleation mechanism. Int. J. Heat and Mass Transfer. 52, 5459-5471 (2009).
- Barber, J., Brutin, D., Tadrist, L. A review on boiling heat transfer enhancement with nanofluids. Nanoscale Res. Lett. 6 (1), 280 (2011).
- Kim, S. J., Bang, I. C., Buongiorno, J., Hu, L. W. Effects of nanoparticle deposition on surface wettability influencing boiling heat transfer in nanofluids. Appl. Phys. Lett. 89, 153107 (2006).
- Berenson, P. J. Experiments on pool-boiling heat transfer. Int. J. Heat Mass Transfer. 5 (10), 985-999 (1962).
- You, S. M., Simon, T. W., Bar-Cohen, A. A technique for enhancing boiling heat transfer with application to cooling of electronic equipment. IEEE Trans. Compon. Hybrids Manuf. Tech. 15 (5), 823-831 (1992).
- Li, C., Peterson, G. P. Parametric study of pool boiling on horizontal highly conductive microporous coated surfaces. J. Heat Transfer. 129 (11), 1465-1475 (2007).
- Trisaksri, V., Wongwises, S. Critical review of heat transfer characteristics of nanofluids. Renew. Sust. Energy Rev. 11 (3), 512-523 (2007).
- Trisaksri, V., Wongwises, S. Nucleate Pool Boiling Heat Transfer of TiO2-R141b nanofluids. Int. J. Heat Mass Transfer. 52 (5-6), 1582-1588 (2009).
- Suriyawong, A., Wongwises, S. Nucleate pool boiling heat transfer characteristics of TiO2- water nanofluids at very low concentrations. Exp. Therm. Fluid Sci. 34 (8), 992-999 (2010).
- Suriyawong, A., Dalkilic, A. S., Wongwises, S. Nucleate Pool Boiling Heat Transfer Correlation for TiO2-Water Nanofluids. J. ASTM Int. 9 (5), 1-12 (2012).
- Sarangi, S., Weibel, J. A., Garimella, S. V. Effect of particle size on surface-coating enhancement of pool boiling heat transfer. Int. J. Heat Mass Transfer. 81, 103-113 (2015).
- Kumar, C. S. S., Suresh, S., Kumar, M. C. S., Gopi, V. Effect of surfactant addition on hydrophilicity of ZnO-Al2O3 composite and enhancement of flow boiling heat transfer. Exp. Therm. Fluid Sci. 70, 325-334 (2016).
- Takata, Y., Hidaka, S., Uraguchi, T. Boiling feature on a super water-repellent surface. Heat Transfer Eng. 27 (8), 25-30 (2006).
- Takata, Y., Hidaka, S., Masuda, M., Ito, T. Pool boiling on a super hydrophilic surface. Int. J. Energy Res. 27 (2), 111-119 (2003).
- Takata, Y., Hidaka, S., Kohno, M. Enhanced nucleate boiling by super hydrophobic coating with checkered and spotted patterns. International Conference on Boiling Heat Transfer. , (2006).
- Hsu, C. C., Chiu, W. C., Kuo, L. S., Chen, P. H. Reversed boiling curve phenomenon on surfaces with interlaced wettability. AIP Advances. 4, 107110 (2014).
- Jo, H., Ahn, H. S., Kang, S. H., Kim, M. H. A study of nucleate boiling heat transfer on hydrophilic, hydrophobic and heterogeneous wetting surface. Int. J. Heat Mass Transfer. 54 (25-26), 5643-5652 (2011).
- Mehta, J. S., Kandlikar, S. G. Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure, Part I: Experimental results for circumferential rectangular open microchannels. Int. J. Heat Mass Transfer. 64, 1205-1215 (2013).
- Cornwell, K., Houston, S. D. Nucleate Pool Boiling on Horizontal Tubes – a Convection-Based Correlation. Int. J. Heat Mass Transfer. 37, 303-309 (1994).
- Holman, J. P. . Experimental Methods for Engineers. , (2007).
