Emissions Pollutant from Diesel, Biodiesel and Natural Gas Refuse Collection Vehicles in Urban Areas - Highway and Urban Environment - page 134

Fig. 3 Installation of the measurement equipment in a refuse truck with lateral loading

The installation of the exhaust gas flow meter is also shown in Fig. 3 , with its Pitot
tubes, sample gas outlet and exhaust temperature sensor.

Analysis Methodology

On-board emissions measurements were conducted in real-world driving conditions
on a specific driving route in the city of Madrid. Although chassis dynamometer
drive cycles exists for heavy duty vehicles [1, 2] , on-road test represent the field
evaluation of the exhaust after-treatment system development, under real-world
operating conditions in the vehicle [3-5] .

Driving Cycle

The first step in the data analysis was the separation of in-use vehicle data into a
number of distinct operational segments or categories specific to the refuse applica-
tion. Figure 4 shows a sample of vehicle speed data based on which the operational
categories were defined [6] . Route segment include:

• Approach

• Collection

• Transfer to Dump

• Dump

• Return

Data sequences for each segment were analyzed to determine their emission
contributions. The characteristics of all the segments significantly differ. For example,
the Approach, Transfer to Dump, and Return segments involve no refuse compac-
tions (i.e., no use of body hydraulics or power-take-off operation). Collection
segment is a combination of kinematic and hydraulic operation. The Dump category
does not involve significant vehicle motion, basically power-take-off operation.