【作者】 纪民举；

【导师】 李超；

【作者基本信息】 兰州理工大学 ， 化工过程机械， 2008， 硕士

【摘要】 为了提高我国城市道路交通条件下的轻型车用动力——中、小排量汽油机的动态性能,本文在分析和比较各种增压系统特性的基础上,论证了采用涡旋增压系统作为城市工况下轻型车用动力增压系统的必要性和可行性。本文以TU5JP/K自然吸气式汽油机为例,对新型的车用机械式增压系统——涡旋增压器与发动机的匹配理论计算、涡旋增压器的结构设计进行了研究。首先,对涡旋增压器的性能进行了分析。根据涡旋增压器工作时的特点,对增压器的热力学和传热进行了分析,讨论了能量方程、理论压缩循环、工作腔和背压腔的传热;对涡旋增压器的几何特性进行了分析,包括涡旋型线及方程,工作腔容积,容积比和压力比,泄漏线长度;并讨论了增压器工作时的受力情况,分别确定了它所受轴向气体力F_a,切向气体力F_t以及径向气体力F_r的方向和大小的计算方法。其次,对增压系统进行涡旋增压器和发动机的匹配理论计算。选择合适的增压度和发动机的一些指标参数,在发动机的中、低转速范围内考察发动机所需的空气流量,分析发动机的转速与空气流量之间的关系。在此基础上,对发动机和涡旋增压器匹配时的增压压力、进气温度进行计算,分析了压力比与发动机转速、进气温度与压力比之间的关系。鉴于涡旋增压器的工作特点以及与发动机最佳匹配的原则,合理确定匹配参数。再次,根据涡旋增压器和发动机匹配的参数,对涡旋增压器进行结构设计。以获得增压器最佳性能为目的,确定了涡旋增压器的型线。考虑增压器的工作原理、密封性、制造加工、外形尺寸、涡旋体的受力等多方面的因素,并对增压器和发动机匹配时的吸气容积进行计算,然后按照增压器和发动机匹配的基本参数对涡旋增压器的基本结构进行设计计算。然后,对增压后涡旋增压器和发动机匹配的调整进行了简要的研究,如对进气中冷、空气量调节、进排气系统、燃烧系统、压缩比、润滑系统的调整以及增压器在发动机上的安装等。得出一些汽油机增压后的调整方案。最后,在总结全文内容的基础上,对车用涡旋增压系统的应用前景作了展望。更多还原

【Abstract】 In order to improve the transient characteristics of gasoline engine in the light-duty vehicle including truck and bus running in Chinese cities, the paper deeply demonstrates the necessary and probability of fixing scroll supercharger for light-duty vehicle on city’s road after analyzing and comparing with various supercharging systems.The paper takes TU5JP/K naturally aspirated engine as the example and researches the new model mechanical supercharging system—the scroll supercharging system’s theory of matching of supercharger and engine and designs the structure of scroll supercharger.Firstly, the performance of scroll supercharger is analyzed. According to the work characteristics of scroll supercharger the thermodynamics and diathermancy are analyzed, and the energy equation, constringent cycle of theory, transferring heat of the working chanber and back pressure cavity are discussed. And the geometric characteristic of scroll supercharger is analyzed, including the scroll profile, profile equation, the working chamber volume, volume ratio and pressure ratio, the leakage wire length. Then the scroll supercharged vehicle engine’s mechanic characteristic is discussed, and the calculational method of axes-pressure, tangency-pressure, and radial-pressure are established.Secondly, the matching of supercharger and engine for scroll supercharging system is calculaed theoretically. The appropriate supercharging degree and some parameters of engine are chosen. Study the air flux of engine in the range of medium and low speed of engine, and then analyze the relation of air flux with engine speed. On the base of it, the pressure of supercharging and the inlet temperature are calculated, and then the relation of pressure ratio with engine speed and inlet temperature with pressure ratio is analyzed. In the light of the work characteristics of scroll supercharger and the best match of supercharger and engine, the matching parameters are decided reasonably.Thirdly, according to the matching parameters of scroll supercharger and engine, the structure of scroll supercharger is designed. The scroll form of supercharge is selected to get the best performance of supercharger. Some factors of the operating principle of scroll supercharger, sealing performance, manufacture, supercharger size and the mechanic characteristic of scroll form are considered, and the inspiratory volume of supercharge is calculated, then the structure of scroll supercharger is designed in term of the matching parameters of supercharger and engine.Fourthly, the adjust of matching of engine and scroll supercharger are simply studied, such as air inter-cooler, adjust of air flux, inlet air and discharge air systems, combustion system, compresson ratio, lubricate system and fixing of supercharger on the engine and so on. And some adjustable blue prints of the supercharged gasoline engine are gained.Finally, on the base of summarizing whole content, the applied foreground of the scroll supercharging system is expected.更多还原