高效相变工业余热回收机理研究

发布时间：2018-03-23 15:05

本文选题：潜热型纳米相变热功能流体　切入点：微通道　出处：《南昌大学》2013年硕士论文

【摘要】：作为高能耗行业代表,过程工业余热资源亟待回收利用,而相关技术与理论的研究还处在起步阶段,尚不能实现低温工业余热高效回收利用,潜热型纳米相变热功能流体微通道余热回收装置是解决这一技术难题最先进的余热回收技术,但其工业应用仍存在许多关键科学问题亟待研究。弄清潜热型纳米相变热功能流体的非常规流动和强化传热机理,是解决工业余热高效回收的理论前提,该研究对开发具有我国知识产权工业余热高效回收技术和装置,以及我国的节能和环保事业均具有重要意义。为此,本文对潜热型纳米相变热功能流体在微通道内层流流动时的强化传热机理和潜热型纳米相变热功能流体微通道余热回收装置的余热回收机理进行了数值模拟研究。本文取得主要成果如下： (1)本文基于强化传热的场协同原理和潜热型纳米相变热功能流体有机结合,建立了潜热型纳米相变热功能流体微通道强化传热物理机制及潜热型纳米相变热功能流体在微通道内流动与传热问题相适应的数值模拟方法。 (2)研究表明,在定热流条件和定壁温条件下都有,纳米PCM颗粒浓度c、纳米PCM颗粒的相变潜热LH和雷诺数Re增大,则微通道潜热型纳米相变热功能流体传热强化效果增强,而初始过冷度Ti-Ts、相变温度范围TL-TS对纳米相变流体强化传热影响不是很明显。 (3)研究表明,潜热型纳米相变热功能流体微通道余热回收装置比传统单相流体微通道余热回收装置具有明显的强化传热效果,其强化传热程度随着纳米PCM颗粒浓度c、纳米PCM颗粒的相变潜热LH、输运流体流速u增大而增强,在c=25%和LH=271kJ/kg二种条件下,其强化传热效果分别高达34.9%和39.16%；提高c、LH、u,有利于提高潜热型纳米相变热功能流体微通道工业余热回收装置的强化传热效果。
[Abstract]:As a representative of high energy consumption industry, the waste heat resource of process industry needs to be recycled, but the research of related technology and theory is still in its infancy, and it can not realize the efficient recovery and utilization of low temperature industrial waste heat. The latent heat recovery device with nanometer phase change heat function fluid microchannel is the most advanced waste heat recovery technology to solve this technical problem. However, there are still many key scientific problems to be studied in industrial application. It is a theoretical prerequisite for efficient recovery of industrial waste heat to make clear the unconventional flow and enhanced heat transfer mechanism of latent heat nano-phase change heat functional fluid. This research is of great significance to the development of efficient recovery technology and equipment for waste heat in the intellectual property industry of China, as well as to the cause of energy conservation and environmental protection in China. In this paper, the mechanism of enhanced heat transfer of latent heat nanocrystalline phase change heat functional fluid in laminar flow in microchannel and the residual heat recovery mechanism of micro channel waste heat recovery device of latent heat nano phase change heat functional fluid have been numerically simulated. ... the main achievements of this paper are as follows:. 1) based on the field synergy principle of enhanced heat transfer and the organic combination of latent heat type nano-phase change thermal functional fluid, The physical mechanism of heat transfer enhancement by microchannel of latent heat nanostructured phase change heat functional fluid and the numerical simulation method for the flow of latent heat nano phase change heat functional fluid in microchannel are established. The results show that under constant heat flux and constant wall temperature, the heat transfer enhancement effect of nanocrystalline PCM particle concentration c, phase change latent heat LH and Reynolds number re of nanometer PCM particle increases, and the heat transfer enhancement effect of micro channel latent heat type nano phase change thermal functional fluid is enhanced. However, the effect of initial undercooling Ti-Ts and phase transition temperature range (TL-TS) on the enhancement of heat transfer of nanocrystalline phase change fluids is not obvious. The results show that the latent heat type nano-phase change heat functional fluid micro-channel heat recovery device has obvious heat transfer enhancement effect compared with the traditional single-phase fluid micro-channel residual heat recovery device. The degree of heat transfer enhancement increases with the increase of the concentration of nanometer PCM particles, the latent heat of phase change of PCM nanoparticles, and the flow rate u of the transport fluid. Under the conditions of 25% C ~ (2 +) and 2% LH=271kJ/kg, the enhancement of heat transfer is enhanced. The heat transfer enhancement effect is up to 34.9% and 39.16%, respectively, and the enhancement of the heat transfer efficiency of the industrial waste heat recovery device of the latent heat nanosized phase change heat function fluid microchannel is improved.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TQ021.3

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