车用燃油加热器的优化设计与计算

【作者】 刘海涛；

【导师】 毛华永； 李国祥；

【作者基本信息】 山东大学 ， 动力机械及工程， 2005， 硕士

【摘要】 随着人们对乘车舒适性要求的提高,加热器在寒冷地区的行车上得到了越来越多的应用。但由于国内关于加热器内气体流动和燃烧方面的研究很少,这就严重制约了加热器性能的提高。同国外产品相比,国内加热器尚存在着许多问题,如工作性能差、燃烧效率低、排放水平较高等。本文在借鉴国内外先进技术的基础上,利用FIRE软件进行了加热器燃烧室内的气体流动、雾化及燃烧过程的数值模拟计算和分析。 在加热器中作为供油系统核心部件的转子式齿轮泵,对加热器的工作性能有着至关重要的影响。本文利用VB6.0及CAD的AutoLisp软件建立了一套转予式齿轮泵的外形尺寸、工作性能及动态运行模拟的程序。 本文做的另外一部分工作是加热器燃烧室内的气体流动、雾化及燃烧过程的数值模拟计算和分析。通过对德国5kW机型、我们课题组为河北宏业集团所设计的5kW在用机型及在该机型基础上进一步探索的数种气流组织方案的模拟计算和分析,为燃烧室内流场组织的改进提供了依据,总结出加热器燃烧室的气流组织对其燃烧效率、排放物的生成及温度场的分布的影响及其变化规律。在此基础上提出在对加热器外部结构及加热器燃烧室内部外形尺寸不进行修改前提下,通过利用合理的气流组织来达到提高加热器工作性能、提高燃油利用率和降低排放的方法。 这种改进方法不仅可以较大地节省现有机型的改进设计成本,而且也为新机型的设计开发提供了有益的探讨和规律总结,为提高加热器的性能指明了方向。更多还原

【Abstract】 With the increasing demand on the comfort of the automobiles, the heater is commonly applied on them. But the improvement of the heater is hold back due to the scarce of reaserch on the fluent and combustion. Compared with the foreign advanced heater, the domestics have a lot of shortcomings, such as bad working performance, low combustion efficiency and higher discharge. In this text, base on the advanced abroad developed technology, the fluent and combustion of heater chamber, was simulated and analysed by utilizing CFD software —FIRE.As the most important apartment, performance of the pump has essential influence on fuel supply system. In this paper, MS VB6.0 and CAD AutoLisp were used to setup a suit of softwares, which can not only calculate the external dimensions of pump, but also simulate the operation of it.The other part of this work is the simulatation of the combustion system. In this part, the simulation of gas fluent and combustion of chamber are done. Through the comparation and analyse the results of different structure schemes of simulation and calculation, the regulars and differences of them can be got. With the regulars, we know that the flow structures can influent not only on the performance of heater, but also discharges. So a perfect flow structure is essential for a wonderful heater. Enhancing the performer of heater and reducing the discharge by means of reforming the flow structure, is very useful and economical. All the information that we get from the simulations can be great useful in designing some new heaters.更多还原