【作者】 潘世艳；

【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， 2008， 硕士

【摘要】 汽车加热器是低温条件下发动机冷起动,车厢供暖,挡风玻璃除霜的重要辅助装置,在国内外均有良好的应用前景。国外的汽车加热器的研究和应用的起步较早,发展到现在技术已很成熟,产品种类也很丰富。与国外相比国内的加热器研究起步较晚,从刚开始的仿制阶段发展到今天已具备了独立研发和生产新型汽车加热器的能力。山东大学在汽车加热器方面的研究走在国内其他高校的前列,其与河北宏业机械股份有限公司合作,共同开发了多种型号的汽车加热器,并获得多项发明专利,拥有自主知识产权。新型加热器的研制往往采用理论与经验相结合的方法,先设计试制出样机,然后根据样机试验进一步改进和确定新产品的各项技术指标。这种研发模式存在成本高,周期长的不足。随着计算机技术的不断发展和进步,数值模拟技术也日趋完善,在各个工程技术领域发挥着越来越重要的作用,正指导着新产品的设计和完善。在已经批量生产的产品的优化方面,数值模拟技术同样起着不可替代的作用。本课题就是运用CFD流体仿真软件Star-CD对河北宏业机械股份有限公司的YJP-Q32型喷雾雾化式汽车加热器进行优化设计,并对计算结果进行了试验对比验证。整个课题的研究工作可分为理论研究、数值模拟和试验验证三部分。理论研究部分主要查阅了国内外有关燃油雾化及混合燃烧的文献和有关CFD数值模拟技术理论方法的文献,以对后续的数值模拟和加热器结构改进提供理论指导和借鉴。数值模拟部分又可分为建模、计算和结果后处理三部分工作。计算的几何模型是根据该型号加热器的技术图纸经过适当简化用Pro-e软件得到,网格模型用Star-CD软件自带的工具包获得。计算条件和边界条件的设定则主要参考Star-CD软件的帮助文件完成。结果后处理则根据模拟计算所要考察的结构的关键部分进行分析对比。主要进行了燃烧器内助燃风流动计算和45°、60°、80°三种喷雾锥角下的喷雾和燃烧排放计算。试验验证是在课题组自行搭建的加热器试验台上完成,主要研究了不同工况下加热器的热效率和排放情况。通过燃烧器内的助燃风流动模拟计算发现该燃烧器后部存在旋流较弱的问题,不利于燃烧过程后期的掺混,从而导致燃烧室后部及燃烧筒内的燃烧温度场分布不均匀,局部高温造成后燃期生成浓度较高的NO,造成NO排放较高。通过对三种喷雾锥角的燃烧计算结果进行对比,发现相同喷油量下80度喷雾锥角的最高燃烧温度较高,从而热效率较高,而且与其他两种喷雾锥角相比NO和炭烟排放没有明显升高,故80度喷雾锥角较好。这一计算分析结果也与试验结果一致。更多还原

【Abstract】 Vehicle heater is an important assistant facility used for cold engine starting, carriage heating and windshield hoarfrost removing, which has good application future both in home and abroad. Vehicle heater research and application started earlier abroad, they have mature technology and abundant products up to now. Compared with them, vehicle heater research began a little later home. From the modeling beginning to now, we already have the ability of developing and manufacturing new heater all by ourselves. Shandong University is in front among other universities in vehicle heater research. Shandong University and Hebei Hongye Mechanical Ltd. cooperate with each other and have developed several types of new vehicle heaters, and what’s more , we have got several invention patents and have our own intellectual property rights.The way of traditional new product development is to combine theory with experience. First design and make a muster, then evaluate and improve the technical parameters of the new product by experiments, which is a big cost of time and money. With the development of computer technology, numerical simulation is becoming more and more advanced, which plays more and more important part in various project fields and gives instruction to the improvement of new products. And for the optimization of products which have already been manufactured in batches and in use, numerical simulation also plays an important role. This project was carried out with the CFD software Star-CD to optimize the YJP-Q32 spray atomization vehicle heater of Hebei Hongye Mechanical Ltd. And the simulation results were compared with the experimentation results, too.The whole work of the project can be divided into three parts, namely theory research, numerical simulation and experimentation validation. The theory research part mainly consulted the literature about fuel spray , mixture and combustion together with CFD numerical simulation theory, which can provide theory induction for the after simulation and configuration improvement of the burner. The numerical simulation part consists of three parts, including model creation, simulation and post progress. The geometry model was created by Pro-e software according to the drawings of the heater with some predigestion. And the gridding model was made with the tools of Star-CD. The computational and boundary conditions were determined according to the tutorial of Star-CD. The post progressing mainly carried out compare and analysis of critical parts of the configuration. The main work is about the air flow inside the burner, together with spray and combustion simulation with cone angel of 45、60 and 80 degrees. The experiments were made at test-bed set up by ourselves. The main goal is to compare the heat efficiency and emission of the heater under different work conditions.From the simulation results of air flow inside the burner, it is found that the swirl at the rearward of the heater is too weak, which is disadvantage for the mixture and combustion, as may result in high NO emission. Through analysis of three different cone angel simulation results, a conclusion was got that the cone angel of 80 degrees is the best, with higher combustion temperature and combustion efficiency and without NO and soot emission increase, which is consistent to the experiment results.更多还原