ORVR车辆加油过程的流动机理与特性研究

发布时间：2018-01-08 08:16

本文关键词：ORVR车辆加油过程的流动机理与特性研究　出处：《北京化工大学》2016年硕士论文　论文类型：学位论文

【摘要】：基于机动车的油气排放控制技术,即车载加油油气回收(Onboard Refueling Vapor Recovery, ORVR)技术, 自美国环境保护署EPA(Environmental Protection Agency, EPA)于1994年推出该技术以来已有20多年的历史。随着我国机动车数量日益增多,机动车污染排放越来越受到人们的重视,ORVR技术也逐渐进入人们的视线,但国内对ORVR技术的认识仍处于起步阶段,相关的基础理论研究寥寥可数,可供参考的相关数据更是微乎其微。为此,本文以ORVR燃油系统为模型,采用参数分析、数值模拟和实验测量相结合的方法,以及相位多普勒三维动态粒子分析仪(Particle Dynamic Analyzer, PDA)、高速摄影仪等先进测试仪器设备,对ORVR车辆加油过程中的气液两相流动特性进行了系统研究。本文首先建立了一种包括加油管、燃油箱和翻车阀等的集总参数法模型,将整个系统分割成4个控制体和2个连接阀。讨论了燃油系统的几何结构、加油枪加油速率、燃油挥发性、燃油箱中的空气／燃油蒸汽比例等参数对压力的影响程度,成功地预测了燃油系统在加油过程中加油管和燃油箱内气相空间的压力变化。然后利用。商业计算流体动力学(Computational Fluid Dynamics,CFD)软件ANSYS FLUENT分别对加油管和全尺寸的ORVR燃油系统进行了数值模拟分析,系统研究了加油过程中加油管的液封现象、加油管管口处空气的卷吸现象、加油管中的回流现象、加油管中的流场和燃油箱中气相空间的压力变化,得到了加油速度、加油管内径、翻车阀背压等对气液两相流动的影响,并利用PDA对加油管中的流场进行了测量,测试结果与数值模拟基本吻合,验证了所采用的CFD数值模型的可靠性。机动车加油是一个瞬态过程,为了对加油管中复杂的气液两相流动进行更深入的研究,本文搭建了1：1的有机玻璃加油管、燃油箱组成的可视化实验平台,采用PDA和高速摄影仪等设备,测量了加油过程中加油管内的速度流场、加油管管口和燃油箱顶部空间的压力变化,系统观察了加油过程中层流流动到湍流流动的转变过程、沿着加油管轴线的涡旋运动的发展过程、空气的卷吸和空气与液体的混合过程。本文研究成果揭示了加油管形成液封的机理及ORVR燃油系统加油过程中的流动特性和压力变化,为国内自主研发ORVR系统提供了可靠数据。
[Abstract]:Motor vehicle emission control technology based on oil and gas, namely vehicle gas oil and gas recovery (Onboard Refueling Vapor Recovery ORVR) technology, since the United States Environmental Protection Agency (Environmental EPA Protection Agency, EPA) launched in 1994 has a history of over 20 years since the technology. With the increasing number of motor vehicles in China, more and more vehicle emission people's attention, ORVR technology has gradually entered the sight of people, but the understanding of ORVR technology is still at the starting stage, very few basic theoretical research related to the relevant data for reference is very little. Therefore, this paper uses ORVR fuel system as a model, using the method of parameter analysis, numerical simulation and experimental measurement. With the phase Doppler particle analyzer and dynamic three-dimensional (Particle Dynamic Analyzer, PDA), high-speed photography and other advanced testing equipment, to ORVR The gas-liquid two-phase flow characteristics of the vehicle refueling process were studied. The paper has established a including gas pipe, lumped parameter method model of the fuel tank and rollover valve, divide the whole system into 4 control and 2 connection valve. Discuss the geometrical structure of fuel system, refueling refueling gun the rate of volatile fuel in the fuel tank, the influence degree of the air / fuel ratio and other parameters of the steam pressure, successfully predicted the pressure changes in the fuel system during refueling refueling pipe and a fuel tank vapor space. Then using the commercial computational fluid dynamics (Computational Fluid, Dynamics, CFD) ANSYS FLUENT software respectively. The numerical simulation analysis of gas pipe and the full size of the ORVR fuel system, the system of gas in the process gas pipe fluid seal gas outlet pipe, air entrainment phenomenon, gas pipe in the back The flow phenomena, flow field and gas pressure pipe of fuel tank in gas phase space, the gas velocity, gas tube diameter, impact on the rollover valve back pressure of gas-liquid two-phase flow, the flow of gas in the tube and the use of PDA were measured. The test results agree well with the numerical simulation, to verify the reliability of CFD the adopted numerical model. The vehicle refueling is a transient process, in order to further study the complex gas-liquid two-phase flow of gas in the tube, this paper set up the organic glass 1:1 gas pipe, visualization experiment platform composed of fuel tank, using PDA and high speed photography equipment, gas in the process gas flow velocity the tube was measured, gas pressure pipe and the fuel tank top space, observe the transformation process of laminar gas flow in the process of the turbulent flow, vortex gas along the tube axis. The development process of air, the entrainment of air and the mixing process of air and liquid. The research results reveal the mechanism of liquid seal formation and the flow characteristics and pressure changes during the ORVR fuel system filling process, which provides reliable data for the domestic research and development of ORVR system independently.

【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.136

【参考文献】