塑料薄膜微通道流动与传热特性及其应用研究

发布时间：2018-02-05 23:57

本文关键词： 微通道塑料薄膜微换热器数值模拟流动特性传热特性　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：微通道塑料薄膜(Micro Capillary Film, MCF)是一种内含数十条平行中空微通道的塑料薄膜,微通道尺寸为微米级,具有表面积体积比高、成本低、易于大批量生产的特点,在微散热器、微泵、微反应器以及防伪技术等领域有广阔的应用前景。利用挤出加工技术制得的MCF宽14～22mm,厚0.6～0.9mm,28条水力直径在50～300μm的微通道集成。研究了塑料薄膜微通道的几何参数对流体流动与传热特性的影响规律,为MCF在微散热器、防伪技术等领域的应用提供理论参考,本文开展的主要工作有：首先,建立塑料薄膜微通道物理模型,对微通道内流体流动与传热特性进行理论研究和数值模拟。通过理论分析,建立微通道阻力系数、压降、速度分布及努赛尔数(Nu)的数学模型。对不同长短轴比及不同水力直径的椭圆微通道进行数值分析,结果表明：在相同雷诺数下,椭圆微通道长短轴比越大,流体流动阻力越大,Nu数越低；在相同雷诺数下,微通道水力直径越大,Nu数越大,其换热效果越好。其次,设计搭建了塑料薄膜微通道流动与传热实验台。以去离子水为流动工质,对三种不同尺寸的微通道塑料薄膜的流动与传热特性进行了实验研究,分析了微通道几何参数对压降、摩擦系数和Nu数的影响,并将实验值与理论分析和数值模拟结果进行对比,分析误差产生原因,并对微通道流动与传热的理论模型进行修正,为新型聚合物微散热器的开发和应用提供参考。最后,提出了一种基于微通道塑料薄膜的新型防伪技术,拓展了MCF的应用领域。搭建了微通道防伪油墨灌注实验装置,探讨了影响微通道油墨流动的因素。研究发现,微通道长度、微通道水力直径和油墨浓度是影响油墨在塑料薄膜微通道流动的主要因素,为微通道塑料薄膜在防伪领域的应用提供理论依据。
[Abstract]:Microchannel plastic film Micro Capillary Film (MCFs) is a kind of plastic film containing dozens of parallel hollow microchannels. With high surface area volume ratio, low cost, easy to mass production characteristics, in the micro radiator, micro pump. The microreactor and anti-counterfeiting technology have a wide application prospect. The MCF prepared by extrusion technology has a width of 14 ~ 22 mm and a thickness of 0.6 ~ 0. 9 mm. 28 microchannels with a hydraulic diameter of 50 ~ 300 渭 m were integrated. The effect of geometric parameters of plastic film microchannels on fluid flow and heat transfer characteristics was studied. The results show that MCF is in the micro radiator. The application of anti-counterfeiting technology provides theoretical reference. The main work of this paper is as follows: firstly, the physical model of microchannel of plastic film is established. The flow and heat transfer characteristics in microchannels are studied theoretically and numerically. The resistance coefficient and pressure drop of microchannel are established by theoretical analysis. Numerical analysis of elliptical microchannels with different axial ratios and hydraulic diameters shows that under the same Reynolds number. The larger the ratio of the long to short axis of the elliptical microchannel is, the greater the flow resistance is, and the lower the Nu number is. At the same Reynolds number, the larger the hydraulic diameter of the microchannel, the better the heat transfer efficiency. Secondly, a plastic film micro-channel flow and heat transfer experiment platform was designed and built. Deionized water was used as the flow medium. The flow and heat transfer characteristics of three kinds of microchannel plastic films with different sizes were studied experimentally. The effects of geometric parameters of microchannel on pressure drop, friction coefficient and Nu number were analyzed. The experimental data are compared with the theoretical analysis and numerical simulation results, the causes of the errors are analyzed, and the theoretical model of microchannel flow and heat transfer is modified. Finally, a new anti-counterfeiting technology based on microchannel plastic film is proposed. The application field of MCF was expanded. The experiment device of anti-counterfeiting ink was set up, and the factors influencing the flow of micro-channel ink were discussed. The length of micro-channel was found. The hydraulic diameter of microchannel and the concentration of ink are the main factors affecting the flow of ink in the plastic film, which provides the theoretical basis for the application of microchannel plastic film in the field of anti-counterfeiting.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK124

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