【作者】 黄勇；

【导师】 高青；

【作者基本信息】 吉林大学 ， 动力机械及工程， 2010， 博士

【摘要】 热流体循环融雪化冰系统是一种新型路面冰雪热融除冰技术,在寒冷的冬季,利用夏季储存的热量来融化道路上的冰雪,从而提高道路安全性,此外,在炎热的夏季,路面还可以太阳辐射吸热,与热量地下储存集成,实现热量的跨季节利用。因此,该新型技术不仅可再生能源季节性利用,有效地降低炎热夏季路面温度,减少路面热蚀破坏,提高道路寿命。路面作为热流体循环融雪化冰系统的基本构造体,担负着冬季融雪化冰热力过程和夏季太阳辐射吸热过程,即释热和集热基本传热过程。本研究以路面冬季融雪化冰和夏季太阳辐射吸热为研究重点,通过实验研究与数值计算分析相结合,探索融雪化冰过程中传热传质特征,路面状况变化特征及时变规律,揭示路面融雪化冰和太阳能辐射吸热过程中传热机理和变化规律,推动路面融雪化冰新技术的发展和科技进步。研究工作主要包括循环热流动路面融雪化冰过程分析、特征研究和仿真计算,以及太阳辐射吸热过程研究。其一,系统研究了基于路面不同降融雪过程基本热特征,并结合客观融雪方式,提出静态融雪、非预热式降融同步、预热式降融同步等基本过程,揭示其内在的温变规律、能量特性,以及相关的热特征和影响作用差异;其二,系统研究了基于路面冰融过程融冰热力特性,以可变负荷加热面实验为基础,探讨融冰特性和影响作用因素关系,获得负荷特征关系;其三,系统开展了路面融雪化冰基本传热分析,在客观解析融雪化冰单元过程的基础上,提出表征基本热现象的传热控制方程,并基于MATLAB—Simulink,建立了路面融雪模型,形成基本组合模块,由此进一步分析融雪化冰过程的路面温度特征和能源特性,同时为面融雪化冰集成系统及其控制策略研究提供了基本手段,并依此进行了路面融雪化冰集成系统仿真分析,进一步研究路面融雪系统可采取的各种主动融雪方式;其四,针对道路夏季吸热过程,利用热力分析和光谱分析,进行了不同道路材料和不同道路表面形态下的太阳辐射热吸收性,以及循环热流体太阳辐射集热性能的研究。融雪过程分为静态融雪和动态融雪过程,动态融雪过程又有提前预热和非提前预热之分。因此,本文以可控电加热方式代替实际工程中热泵加热装置,建立了一套冬季路面融雪实验装置和实验系统,研究此三种不同降融雪过程。根据路面状况和路面温度评估路面融雪能力,根据融雪耗能特征评估融雪过程中能量的利用效能和热交换能力。从而为路面融雪化冰系统的设计提供重要的依据。冬季路面结冰而使道路表面摩擦力大大降低,研究路面融冰特性很有必要。本文采用可控电加热碳纤维管加热方式,以及采用缩小比例的模拟道路,建立了一套寒冷环境下模拟路面融冰实验装置,研究路面融冰过程中的融冰特性,以及传热传质特性规律。根据融冰率的变化和冰层温度的变化来反映融冰特性,同时分析冰层厚度、冰融水流动、加热管节距以及埋管布置形式对冰层热融过程的影响。从而为路面融冰设计提供重要的指导。冬季路面融雪化冰系统是一个复杂的传热传质和有相变发生的过程,通过编写S函数自建各种仿真模块,包括路面融雪化冰模块、热泵模块、循环水泵模块、地下换热器模块和控制器模块等,从而组建完整的冬季路面融雪化冰集成系统。通过单次融雪过程和单个冬季融雪过程,对衡量系统能力的特征参数表面无雪率和路面温度做了详细分析,提出系统经济性指标热泵性能系数和能耗指标,通过对比不同降雪量、不同室外空气温度和不同地下初始温度,分别对系统经济性做了评价。研究结果表明提高地下土壤初始温度可以有效增强系统性能,而适当提高地下土壤温度,可以通过夏季路面集热蓄能来实现。因此,太阳辐射集热研究显得很有必要。路面太阳辐射集热对冬季路面融雪化冰具有重要的意义。然而,不同材料道路和不同表面形态道路对太阳辐射集热具有不同的吸热性和集热性能。因此,本文分别对不同材料道路和不同表面形态道路下的太阳辐射吸热做了详细分析。从温度和辐射反射光谱的角度,重点分析太阳辐射的热吸收性,探索其间的温变特性和导热能力。同时,针对不同路面形态的道路,研究其太阳辐射集热性能的变化规律,分析单位面积集热量和集热效率的变化,进一步指导工程应用。更多还原

【Abstract】 Hydronic Ice-Snow Melting (HISM) system is a new kind of Hot Melting De-Icing technology, by using the heat collecting in summer to melt the snow and ice on the road in winter, which can improve road safety. While in the hot summer, it uses the road to absorb solar radiation and stores it to the ground for winter use. This technology not only can realize the seasonal application of renewable energy, but also can effectively reduce the pavement surface temperature in hot summer, reduce the rate of heat corrosion and extend the life of the pavement adequately.Road surface, as a basic structure in HISM system, bears the thermodynamic process of winter ice-snow melting and heat absorption process of summer solar radiation, which is the basic heat transfer process of heat release and heat collection. Therefore, this paper will focus on road ice-snow melting in winter and slab solar collection in summer by combining with experimental investigation and analog simulation, to explore the heat transfer and mass transfer characteristic in ice-snow melting and variation of surface condition and time-varying feature of underground soil, to discover the mechanism of heat transfer and mass transfer in road ice-snow melting process and slab solar collection for technological improvement of road ice-snow melting.The main works of this paper are consisted of the analysis of the process, characteristics researches and simulation of HISM system and the study of heat absorption process of solar radiation. At first, based on different snow falling and melting process on road, the basic heating characteristics was studied systematically, and presented basic processes of static snow melting, dynamic snow melting and preheating snow melting process, to reveal their inside variation rules of temperature, energy character, relative heat character and the difference of influences; At second, depending on the experiment of variable load heating surface, the ice melting characteristic in the process of surface ice melting was studied systematically, to discuss the ice melting characteristics and impacts for getting the relation of load character; At third, basic heat transfer analysis was carried out systematically on HISM system, on the base of resolving the process of HISM unit objectively, heat transfer control equations presenting the basic thermal phenomena was brought up, and based on MATLAB-Simulink, a model of HISM was built to form a fundamental module of the integrated system, and from this module, surface temperature and energy characteristics in the process of HISM were analyzed further, so it provided a powerful method for the research of integrated HISM system and its control strategy, and an analog simulation of this integrated system was taken for a further research of HISM system with several dynamic snow melting method available; At fourth, as to heat absorption of solar radiation on road in summer, by using thermodynamic analysis and spectral analysis, heat absorption experiments with different road materials and different road morphology and heat collection experiment of solar radiation were carried out.The snow melting process can be divided into static melting and dynamic melting, and the latter one can be divided into preheating melting and non preheating melting. Therefore, a set of experimental system of road snow melting was built by using electric heating hot fluid with controlled temperature, instead of heat pump heating devices in practical engineering to study the three processes with different snowfalling characteristics. Depending on surface condition and surface temperature, the ability of road snow melting was evaluated, and depending on energy consumption of snow melting, the utilization efficiency of energy and heat exchange capacity was evaluated. So, it provides an important basis of the design of HISM system.Because of the icy road, that will heavily reduce the surface friction, it becomes necessary to study the characteristics of road ice melting. In this paper, by using a scaled down stimulant, a set of experimental facility was built, which used controllable electric heating carbon fiber, for the study on the characteristics of ice melting and heat transfer and mass transfer characteristic. Depending on ice melting rate and the variation of ice-layer temperature, ice melting characteristics was analyzed. Meanwhile, the effect of heating load, thickness of ice-layer, ice water flowing, spacing of heating pipe and arrangement of pipe on ice melting were analyzed. So, it provides an important guidance to the design of ice melting system.Road ice-snow melting system of winter is a complex heat and mass transfer process with phase transformation. By writing S function to build various simulation modules by myself, including road ice-snow melting module, heat pump module, circulating pump module, GLHE module and controller module, etc, an integrated HISM system was set up. Snow free area ratio and surface temperature that are feature parameters to measure the system capacity were analyzed through single snow melting process and whole winter process. And meanwhile, two economic indicators of the system, COP of heat pump and energy consumption, were presented. By comparing different snowfall, different outdoor air temperatures and different initial underground temperature, an anlysis were done on the economic evaluation of the system. The results indicated that raising the temperature of underground soil can effectively improve the performance of the system. And the way to raise the temperature of underground soil can be realized by heat collection in summer. Therefore, the study on slab solar collection seems to be necessary.It is important of slab solar radiation collection to road ice-snow melting of winter. However, different absorbability of solar radiation and heat collecting performance are arisen on different material slabs and different configuration slabs. Therefore, in this paper, these two kinds of slabs were studied. From the view of temperature and reflection spectrum, the absorbability of solar radiation was analyzed mainly to explore the characteristic of temperature variation and the capacity of heat transmission. Meanwhile, for different configuration slabs, the performance of heat collection under solar radiation was studied, and the characteristic of heat quantity per unit area and heat collecting efficiency were analyzed for further application of practical engineering.更多还原