Abstract

This paper aims to evaluate the potential of lubricating pumps to reduce the fuel consumption of passenger cars under the standardized driving cycles conditions. The transient parameters of lubricating pump in a gasoline engine are measured based on the test bench, and a quasi-steady-state model is brought forward to calculate the matching work state of lubricating pump and engine lubricating system. The result shows that a certain amount of excessive hydraulic power is needed under low speed condition to meet the step increase of lubricating requirement. In the range over piston spray cooling speed, the excessive hydraulic power of lubricating system is proportional to engine speed, and this part of driving power can be saved. The duration of acceleration conditions in driving cycles and the lubricant temperature are the most critical factors affecting the lubricating pump’s driving power. At 100 °C, the lunricating system driving energy costed in the Urban Driving Cycle (UDC) is 60.2% lower than 25 °C, but it is 42.1% in the World-wide harmonized Light duty Test Cycle (WLTC) due to the increase of acceleration condition. With a fully variable lubrication pump, the driving energy levels can reduce by 5.76%, 8.96%, 32.1% in WLTC, Extra-Urban Driving Cycle (EUDC), and UDC, respectively.

摘要

本文旨在评估润滑泵在标准化驾驶循环条件下降低乘用车油耗的潜力。基于试验台架对汽油机润滑油泵的瞬态参数进行测量，提出准稳态模型计算润滑油泵与发动机润滑系统的匹配工作状态。结果表明，在低速工况下，需要一定量的过剩液压动力来满足润滑要求的阶跃增加。在超过活塞喷雾冷却速度范围内，润滑系统多余的液压功率与发动机转速成正比，这部分驱动功率可以节省下来。驾驶循环中加速条件的持续时间和润滑油温度是影响润滑泵驱动功率的最关键因素。在 100 °C 时，城市驾驶循环 (UDC) 中的润滑系统驱动能量成本比 25 °C 低 60.2%，但由于增加的增加，在全球协调轻型测试循环 (WLTC) 中为 42.1%的加速条件。采用全可变润滑泵，在 WLTC、Extra-Urban Driving Cycle (EUDC) 和 UDC 中，驱动能量水平可分别降低 5.76%、8.96%、32.1%。