重型柴油车实际道路油耗与排放模拟及其应用研究

基于实际行驶状态下重型车动力需求和传动系统变化规律,建立了重型柴油车整车的瞬态油耗和排放模拟方法,可实现整车发动机工况及油耗与排放的实时模拟.为验证模型的有效性,利用重型车车载排放测试手段,以柴油公交车为研究案例,模拟并验证了车辆在实际运营线路上的油耗与排放水平.公交车综合线路实测百公里油耗为16.38L,NOx、CO和THC排放因子分别为4.44、3.35、1.96g·km-1,模拟结果与实测值基本吻合,其油耗与排放因子与实测值之比均在1.06倍左右.模拟结果显示,实测公交车怠速、NOx控制区及其它区域工况点分别占32.6%、7.1%和60.4%,增加10t负载或提高1.5倍车速可使发动机负荷利用率上升,控制区比例上升至18.4%和18.8%,同时增加负载和提高车速,控制区工况可提高至33.9%.相应地,增加负载或提高车速情景分别使车辆油耗与排放上升至1.5～1.7倍和1.6～1.8倍,同时增加负载和提高车速,油耗与排放可增至2.5倍～3.0倍,控制区油耗与排放比例均有大幅度上升.总体上,该模型方法可以为评价和研究重型柴油车在实际道路上的能耗及其排放状况提供新的模拟方法和分析手段.

Real world fuel consumption and emissions simulation and its application for heavy duty diesel vehicles

The purpose of this study is to simulate transient fuel consumption and gas emissions of a heavy duty diesel vehicle in the real world. A new simulation methodology for heavy duty diesel vehicles was developed based on the principles of power demand and transmission system in real world systems. To validate the methodology, a heavy duty diesel bus was selected to be tested on its business route by using an on-board emission measurement system. The fuel economy was 16.38 L·100 km-1. NOx, CO and THC emission factors reached 4.44, 3.35, and 1.96 g·km-1, respectively, and the simulated results were generally in accord with the test data. The fuel and emission factors were 1.06 times the test results. The proportions of driving condition under idling, NOx control zone and other zones of the engine map were 32.6%, 7.1% and 60.4%. If we increase the 10t load or speed up the velocity by 1.5 times, the engine load in the NOx control zone will increase to 18.4% and 18.8%, and the fuel and emission level will be 1.5~1.7 times or 1.6~1.8 times the base case. While integrating these two scenarios, the vehicle will be operated under a high stress load. The share of driving conditions under the NOx control zone will be 33.9%, and the fuel and emission level will increase to 2.5~3.0 times correspondingly. The simulation methodology can be utilized to analyze the second-by-second energy consumption and exhaust gas emissions for heavy duty diesel vehicles in the real world.