小型液暖燃油加热器的设计与开发

【作者】 王伟；

【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， 2007， 硕士

【摘要】 车用燃油加热器是现代汽车冬季取暖的主要设备之一。随着我国汽车产业的迅速发展，国内加热器的市场也得到了快速发展。目前，国产加热器产品主要供国内的客车、公交车以及军事车辆使用的热功率较大加热器，因采用喷雾或甩油雾化燃油，所以加热器体积较大。但适于轿车使用的结构紧凑、热功率小的蒸发式燃油加热器却鲜有出现。鉴于这种情况，本文剖析了国外几种典型的蒸发式燃烧器，设计出一种具有自主知识产权的锥盖形燃烧器，并利用Star-CD软件对燃烧器内部的流动和燃烧进行数值模拟。通过数值模拟的分析和加热器的燃烧试验可看出，锥盖形燃烧器在点火性能，促进油气蒸发混合燃烧，降低燃烧噪音等方面具有一定的优势。在我们课题组的共同努力下，新开发设计了采用锥盖形燃烧器的液暖燃油加热器及其相关的控制器。新型锥盖形燃烧器在结构上省去了压铸件中间体，增加冲压件，而且在热交换体上采取不同高度的散热片，增加导流肋等措施，这样不仅使加热器的结构得到了大大的简化，方便拆装，而且同时保证了加热器的热效率。通过新型液暖燃油加热器的设计与开发，我们在加热器结构简化，提高热效率，以及加热器起动控制等方面积累了一定的经验，为进一步的优化设计打下了坚实的基础。通过对新、老两台蒸发式液暖加热器的性能试验，验证了新型加热器在热功率和热效率基本保持不变的前提下，使加热器内部流动阻力得到明显的降低。同时，试验证明了加热器的进水温度和过量空气系数对加热器的热功率和热效率有很大的影响，而水流量的增大使加热器的热功率和热效率有增大的趋势，但影响并不明显。另外，在分析了现有加热器试验台不足的基础上，通过配备大管径的流量计、改进阀门调节装置、添加放气装置和一套燃油供给系统等措施，使现有加热器试验台能够适应各种不同型号与类型的加热器的试验研究与测量。更多还原

【Abstract】 Fuel-burned heater is one of the main equipments for vehicle heating in winter. With the fast development of industry of automobile, the market of fuel-burned vehicle heater has gained a great increase in the recent few years. At present, big heaters with more than 10 kW heat output are popular in domestic market and these heaters mainly serve for big buses and military vehicles. However, we rarely find the compact and miniature heater for passenger cars with low heat output in home market while it has been used for many years in foreign countries.Considering lacking of miniature heater, our team designed a new kind of burner-the cone vaporizing burner which is suitable for the small heater. The burner has a cone vaporizing body in which liquid fuel is distributed on a comparatively large surface and is vaporized from it .At the same time, the vaporized fuel gas quickly mixes with the tangent flow. So the fuel and air have a good and fast mixture in the burner, that means a shorter start phase and less soot. There is also a cone shrinking hole in the mid part of the burner which is used for stabilizing flame. Then the fluent and combustion in the burner was simulated and analyzed by utilizing CFD software STAR-CD.Moreover, under the endeavor of our team, we devise a new model of water-warmed vehicle heater with so-called cone vaporizing burner and the corresponding controller. We have made great efforts to simplify the structure of the new vehicle heater and improve its heat efficiency. The new vehicle heater can be regarded as a good model to exploit the domestic and oversea market, and it will be successful. Meanwhile, we have applied for patents on the new product.Finally, many experiments were made with the new vehicle heater and an old one on a performance test bench. The results show that the new vehicle heater has lower resistance to both water and air flow with almost the same heat efficiency. We also find that the inlet water temperature and the ratio of air and fuel have a great effect on the heat efficiency of heaters. But the flux has a little impact on the efficiency. In additional, some changes were made to the test bench. After those improvements the test bench can be adapted for different types of fuel burned vehicle heaters, no matter what it is water-warmed or air-warmed.更多还原