实测路谱加载条件下的燃油系统动态泄漏性研究

Research on dynamic fuel leakage of fuel system based on measured Attitude&Heading road-spectrum

车辆燃油系统的动态油液泄漏将严重影响行驶安全与蒸发排放控制水平。基于实测姿态路谱在六自由度台架上探究了国Ⅵ阶段5种类型燃油系统的动态油液泄漏表现,按照炭罐丁烷工作容量测试标准研究了国Ⅵ与国Ⅴ阶段两种排放标准的炭罐在油液泄漏发生后的有效吸附容量变化。结果表明:国Ⅵ阶段部分燃油系统存在不能有效防止动态油液泄漏的隐性设计缺陷,在单次路谱的加载过程中泄漏0~140 mL不等的油液;炭罐的有效吸附容量与进油量呈负相关,国Ⅵ阶段炭罐的有效吸附容量衰减速度可能快于国Ⅴ标准。建立的测试方案和实测姿态路谱数据将完善燃油系统耐久性测试体系,基于油液泄漏量的炭罐有效吸附容量模型将提升在用车蒸发排放量的核算精度。

Dynamic fuel leakage from vehicle fuel systems affects driving safety and evaporative emission control levels.In this study,the Attitude Heading road spectrum was acquired by a vehicle-mounted gyroscope in five scenarios:urban commuter driving,urban and rural transportation driving,long-distance highway driving,extreme terrain driving,and scenic section driving.The outliers of Attitude Heading road-spectrum caused by gyroscope and high-frequency vibration of the vehicle body during acquisition were eliminated by using signal processing methods such as Pauta criterion and Butterworth band-pass filter.Then,the Attitude Heading road spectrum was loaded into a 6-Dof platform and the fuel leakage performance of five types of fuel systems in the China 6 stage under dynamic conditions was studied.Lastly,according to the test method for butane work capacity of carbon canister,the adsorption capacity changes of carbon canisters with China 6 stage and China 5 stage after fuel leakage were studied.Studies have shown that:(1)some fuel systems in the China 6 stage have invisible design defects that cannot effectively prevent dynamic fuel leakage.During the loading process of a single Attitude Heading road spectrum,fuel ranging from 0 to 140 mL is leaked,and the test method for fuel system quality needs to be perfected.(2)The adsorption capacity of the carbon canister is negatively correlated with the amount of fuel intake,and the decay rate of the adsorption capacity of the carbon canister in the China 6 stage may be faster than that in China 5 stage.It is suggested that the gas-liquid separator should be installed in the carbon canister to prevent fuel leakage.The test scheme and the measured Attitude Heading broad-spectrum data in this study can perfect the fuel system durability test system,and the actual adsorption capacity model of the carbon canister based on the fuel leakage can improve the calculation accuracy of the evaporative emissions of in-use vehicles.