基于发动机在环重型车C-WTVC循环油耗影响性研究

Research on influence of C-WTVC test cycle on fuel consumption of the heavy-duty diesel vehicle based on Engine-in-Loop platform

以某款重型柴油车为研究对象,基于发动机在环平台采用C-WTVC测试循环,研究不同换挡策略和不同滑行阻力对油耗的影响。文中通过对高挡位、居中挡位、偏低挡位3种驾驶换挡策略和相同类别车辆选取最大、居中、较小3组不同滑行系数对循环油耗的影响分析。结果发现:驾驶换挡策略不同循环油耗最大偏差为4.4%,最小偏差为0.99%,高挡位驾驶换挡策略的循环油耗最低。市区道路采用低挡位驾驶换挡策略发动机输出功最小,市郊路况不同驾驶换挡策略做功无明显差异,高速路况采用较高挡位输出功最小;不同滑行阻力导致油耗最大偏差为16.46%,最小偏差为6.96%,油耗结果随着滑行阻力增大而增大。分析比较该测试循环市区路况与市郊路况中不同换挡策略、不同滑行系数的油耗试验结果差异,为重型车自动换挡系统的研发与提升燃油经济性提供借鉴。

In this article, with the focus on a heavy-duty diesel vehicle, based on the engine-in-loop platform, the C-WTVC test cycle is adopted to explore the influence of different shifting strategies and various sliding resistance on fuel consumption. By means of the analysis on influence of three shifting strategies of high gear, middle gear and low gear and three groups of the same type of vehicles with different sliding coefficient on fuel consumption, it is found that the maximum deviation of fuel consumption resulting from different shifting strategies is 4.4%, and the minimum deviation is 0.99%. The cycle fuel consumption resulting from the high-gear shifting strategy is the lowest. The results show that the engine’s output power is the minimum when driving in low gear on the urban roads and there is no significant difference between different shifting strategies on the suburb road;the output power is the minimum when driving in high gear on the high-speed roads. Besides, the maximum deviation of fuel consumption caused by different sliding resistance is 16.46%, and the minimum deviation is 6.96%;fuel consumption increases with the ever-growing sliding resistance. Finally, difference in the fuel-consumption experimental results obtained from different shifting strategies and various sliding coefficients in the test cycle of urban road conditions and suburb road conditions are analyzed and compared, which provides reference for research and development of automatic shifting systems of those heavy-duty vehicles on one hand and improvement of fuel economy on the other hand.