Department of Mechanical Engineering, University of California, Riverside, CA, USA.
College of Engineering-Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, CA, USA.
J Air Waste Manag Assoc. 2023 Jul;73(7):568-577. doi: 10.1080/10962247.2023.2205367.
Tailpipe PM (particulate matter) emissions have been reduced due to decades of tightening regulations, however non-tailpipe PM emissions are not regulated and are expected to become a significant source of traffic-related PM emissions. Previous studies have focused on emission measurement from laboratory and track tests. Their findings suggest brake wear PM emission rates are dependent on brake activity. Therefore, it is important to characterize brake emissions by first understanding the real-world brake activity from many different vehicle vocations and driving conditions. The goal of the current study is to establish a test method and analysis for brake activity measurements of heavy-duty vehicles. In this study, brake fluid pressure and brake pad temperature were measured for a heavy-duty vehicle during chassis and on-road driving tests. The chassis tests consisted of the Central Business District (CBD) cycle representative of a repetitive stop-and-go driving pattern of a bus, and the Urban Dynamometer Driving Schedule (UDDS) cycle representative of urban driving conditions of heavy-duty vehicles. The on-road tests consisted of a local Riverside City route focused on urban roads at low vehicle speeds with frequent braking, while the second route from Riverside City to Victorville focused on highway driving and downhill braking. The brake pad temperature of the triplicate CBD cycle gradually increased linearly with a slope of 2.3°C/min and the temperature per kinetic energy lost during braking increased by 2.3 × 10°C/J for the CBD cycle. The UDDS cycles had the largest kinetic energy loss between 3.2 × 10 to 3.0 × 10 J in the histogram. The local Riverside city route brake temperature increased by 2.0°C/min. The kinetic energy loss for the on-road tests were one order of magnitude larger than that of the dynamometer tests due to brake events occurring under higher speeds. The non-tailpipe source contributions to traffic related particulate matter (PM) emissions have surpassed that of tailpipe emissions. The results of this work provide a measurement method to obtain brake activity information for a heavy-duty vehicle, which is critical estimating emission inventory accurately.
由于几十年来法规的不断收紧，尾管 PM（颗粒物）排放量已经减少，但非尾管 PM 排放量不受监管，预计将成为交通相关 PM 排放的重要来源。先前的研究侧重于实验室和轨道测试的排放测量。他们的发现表明，制动磨损 PM 排放率取决于制动活动。因此，通过首先了解来自许多不同车辆用途和驾驶条件的实际制动活动来对制动排放进行特征描述非常重要。本研究的目的是建立一种用于重型车辆制动活动测量的测试方法和分析。在这项研究中，在底盘和道路行驶测试中测量了一辆重型车辆的制动液压力和制动片温度。底盘测试包括中央商务区 (CBD) 循环，该循环代表了公共汽车的反复停车-行驶模式，以及城市动态驾驶计划 (UDDS) 循环，该循环代表了重型车辆的城市驾驶条件。道路测试包括一条以城市道路为主的本地河滨城市路线，该路线以低车速和频繁制动为特点，而从河滨城市到维克多维尔的第二条路线则侧重于高速公路行驶和下坡制动。三倍 CBD 循环的制动片温度逐渐线性增加，斜率为 2.3°C/min，每次制动损失的动能增加 2.3×10°C/J。在直方图中，UDDS 循环的动能损失最大，介于 3.2×10 到 3.0×10 J 之间。本地河滨城市路线的制动温度上升了 2.0°C/min。由于制动事件发生在更高的速度下，道路行驶测试的动能损失比测功机测试大一个数量级。非尾管源对交通相关颗粒物 (PM) 排放的贡献已经超过了尾管排放。这项工作的结果提供了一种获取重型车辆制动活动信息的测量方法，这对于准确估计排放清单至关重要。
