除冰液强化换热研究

发布时间：2018-07-15 12:43

【摘要】：随着我国民航产业的快速发展,整个行业在安全运行的基础上更加重视飞机的运行效率和航班的准点率。在冬季有冰雪天气的机场,如何实现飞机除冰工作的快速化对保证飞机的高效运行有着重要的作用。本文从除冰液加热方面开展研究,考虑高粘度流体的特性,利用FLUNT软件对高粘度流体进行数值模拟,对除冰液的换热过程进行强化,为快速除冰工作提供支持。首先,基于场协同原理,本文对原有除冰液加热系统中的螺旋形盘管进行结构优化。在光滑盘管的基础上添加凹槽,形成有向内凸起的环形肋的横纹螺旋盘管,在SolidWorks软件环境下对光滑盘管和三种优化盘管进行造型。利用网格划分软件ICEM完成对四种盘管的网格生成工作。其次,选择可实现k-?湍流模型,改变不同的速度入口条件,利用FLUENT对水在四种盘管中的换热过程进行数值模拟。结果表明:优化后的横纹螺旋盘管对水的换热过程起到了强化作用,不但使管出口处的水温有较大提升,而且也增强了水温的均匀程度,减小了出口截面处水的温差。最后,根据实际情况,以除冰液的主要成分乙二醇为工质,利用Origin函数绘图软件拟合其粘度随温度变化的曲线,得到精度良好的粘度拟合公式。根据公式,编写FLUENT环境下的UDF函数,修正乙二醇的粘度项,进行数值模拟研究。结果表明:一方面,对于高粘度流体乙二醇,横纹螺旋盘管对其换热过程起到了强化作用,使管出口处的温度有所提升;另一方面,由于其高粘度特性,在加热过程中的初始阶段,与水不同,温度提升幅度较小,出口温度远小于同等条件下水的出口温度;此外,对于乙二醇来说,入口速度的改变对其出口温度的影响较大。本研究可以为除冰液加热系统的优化设计提供理论指导,同时对提高目前飞机的除冰效率有着很大的促进作用。
[Abstract]:With the rapid development of China's civil aviation industry, the whole industry pays more attention to the efficiency of aircraft operation and flight punctuality on the basis of safe operation. In an airport with ice and snow weather in winter, how to speed up the deicing of aircraft plays an important role in ensuring the efficient operation of aircraft. In this paper, from the aspect of deicing fluid heating, the characteristics of high viscosity fluid are considered, and the numerical simulation of high viscosity fluid is carried out by using FLUNT software. The heat transfer process of deicing fluid is strengthened to provide support for rapid deicing work. Firstly, based on the principle of field cooperation, the structure of spiral coil in the original deicing fluid heating system is optimized. On the basis of the smooth coil, the groove is added to form the transverse spiral coil with circular rib raised inward. The smooth coil and three kinds of optimized coil are molded under the environment of SolidWorks software. The grid generation of four kinds of coils is completed by using the grid division software ICEM. Secondly, the choice can be realized k-? The turbulent model is used to simulate the heat transfer process of water in four kinds of coils by using fluent. The results show that the optimized transverse spiral coil can strengthen the heat transfer process of water, not only raise the water temperature at the outlet of the pipe, but also enhance the uniformity of the water temperature and reduce the water temperature difference at the exit section. Finally, according to the actual situation, with ethylene glycol, the main component of deicing liquid, as the working medium, the curve of viscosity with temperature is fitted by Origin function drawing software, and the viscosity fitting formula with good precision is obtained. According to the formula, the UDF function under fluent environment is compiled, the viscosity term of ethylene glycol is modified, and the numerical simulation is carried out. The results show that, on the one hand, for the high viscosity fluid ethylene glycol, the heat transfer process of the transverse spiral coil tube is strengthened, and the temperature at the outlet of the tube is increased, on the other hand, because of its high viscosity, In the initial stage of heating process, unlike water, the temperature rise is smaller and the outlet temperature is much smaller than the outlet temperature of water under the same conditions. In addition, for ethylene glycol, the change of inlet velocity has a great effect on the outlet temperature. This study can provide theoretical guidance for the optimal design of deicing fluid heating system and promote the deicing efficiency of aircraft at present.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V244.15

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