基于道路融雪化冰集热过程传热分析

发布时间：2018-06-17 14:01

本文选题：融雪化冰 + 路面集热　；参考：《吉林大学》2017年硕士论文

【摘要】：路面集热结构是平板式太阳能集热结构的一种。夏季时路面集热系统吸收的能量可以通过蓄能方式储存供冬季道路融雪化冰应用,因此道桥集热和融雪化冰系统是一种复合能源利用的系统。本文针对集热路面的集热过程进行传热分析,从实际工程的集热路面提取几何模型和物理模型。针对集热路面的物理模型特点,选择合适的流动模型和辐射模型,基于集热路面传热分析设定相应的边界条件。通过分析不同工作条件的仿真结果,对路面集热过程的基本性能进行分析。通过仿真模拟探究循环流体的流速和初始温度对集热路面的集热性能的影响。研究显示,在一定范围内随着循环流体流速的增加,集热效率提高,且随着流速的增加,单位面积集热量和集热效率存在峰值。环境因素也对于集热路面的集热过程有一定影响。本文探究了环境风速和太阳辐射强度对路面集热过程的影响。仿真结果显示,随着路面环境风速的增大,循环流体温升逐渐减小,单位流程温差和单位面积集热量也逐渐减小,所以环境风速对于路面集热过程是一个不利因素,集热路面系统应选择在风速较小的天气情况下运行。太阳辐射强度存在峰值时间段,路面温度相对太阳辐射强度变化存在滞后性。除了集热路面工作环境,道路集热结构对路面集热性能也有一定的影响。本文建立了多组不同路面形态、不同管间距、不同管径以及不同置管深度的集热道路网格模型,通过仿真分析道路集热结构对路面集热的影响作用。在一定范围内,减小管间距、增大管径有利于路面集热,其集热效率大幅度提高。环境风速越小、太阳辐射强度越大,路面吸热总量越大,有利于集热系统的集热过程。基于对冬季道路融雪化冰传热过程的分析,根据实际工程需求,提取坡度为15°的弯道/坡路的物理模型,利用VOF模型、融化模型以及流动模型的多模型组合,模拟路面融雪化冰过程。融化的液态水在重力作用下流至道路边缘且在融化过程中,冰雪层的出口处液体的流速存在峰值,斜坡路面减少路面上液态水蒸发的耗热量,有利于减少干燥冰雪路面的能耗。
[Abstract]:Pavement heat collecting structure is a kind of flat solar energy collecting structure. In summer, the energy absorbed by the road surface heat collection system can be stored in the form of energy storage for the application of road snow melting ice in winter, so the road and bridge heat collection and snow melting ice system is a kind of composite energy utilization system. In this paper, the heat transfer analysis is carried out in view of the heat collecting process of the collector pavement, and the geometric and physical models are extracted from the actual engineering heat collecting pavement. According to the characteristics of the physical model of the collector pavement, the appropriate flow model and radiation model are selected, and the corresponding boundary conditions are established based on the heat transfer analysis of the collector pavement. By analyzing the simulation results of different working conditions, the basic performance of pavement heat collecting process is analyzed. The effects of flow velocity and initial temperature of circulating fluid on the performance of collector pavement were investigated by simulation. The results show that the heat collection efficiency increases with the increase of circulating fluid velocity in a certain range, and with the increase of flow velocity, there is a peak value of heat collection and heat collection efficiency per unit area. Environmental factors also have a certain impact on the heat collection process of the road surface. In this paper, the effects of environmental wind speed and solar radiation intensity on the process of road surface heat collection are investigated. The simulation results show that, with the increase of the wind speed, the temperature rise of circulating fluid decreases gradually, the temperature difference per unit flow and the heat accumulation per unit area decrease gradually, so the environmental wind speed is a disadvantageous factor for the process of road surface heat collection. The collector road surface system should be selected to operate under the condition of low wind speed. There is a peak period of solar radiation intensity, and the change of road surface temperature relative to solar radiation intensity is lagging. In addition to the working environment of road surface, the structure of road heat collection also has a certain impact on the performance of road surface heat collection. In this paper, a grid model of a collection road with different pavement shapes, different pipe spacing, different pipe diameters and different pipe-setting depths is established, and the effect of road heat collecting structure on pavement heat collection is analyzed by simulation. In a certain range, reducing the distance between pipes and increasing the diameter of the pipe is beneficial to the collection of heat on the pavement, and its heat collection efficiency is greatly improved. The smaller the ambient wind speed, the greater the solar radiation intensity and the larger the total heat absorption of road surface, which is beneficial to the collection process of heat collection system. Based on the analysis of snowmelt and ice heat transfer process in winter road, the physical model of bend / slope with slope of 15 掳is extracted according to the actual engineering requirements, and the combination of VOF model, melting model and multi-model of flow model is used. The process of snow melting and ice melting is simulated. The melting liquid water flows to the edge of the road under the action of gravity. During the melting process, the flow velocity of the liquid at the exit of the ice and snow layer has a peak value, and the slope pavement reduces the heat consumption of the evaporation of liquid water on the road surface, which is conducive to reducing the energy consumption of the dry ice and snow pavement.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U418.41;TK513

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