Piotr Lijewski

Development of the methodology of exhaust emissions measurement under RDE (Real Driving Emissions) conditions for non-road mobile machinery (NRMM) vehicles

The paper analyzes the exhaust emissions from farm vehicles based on research performed under field conditions (RDE) according to the NTE procedure. This analysis has shown that it is hard to meet the NTE requirements under field conditions (engine operation in the NTE zone for at least 30 seconds). Due to a very high variability of the engine conditions, the share of a valid number of NTE windows in the field test is small throughout the entire test. For this reason, a modification of the measurement and exhaust emissions calculation methodology has been proposed for farm vehicles of the NRMM group. A test has been developed composed of the following phases: trip to the operation site (paved roads) and field operations (including u-turns and maneuvering). The range of the operation time share in individual test phases has been determined. A change in the method of calculating the real exhaust emissions has also been implemented in relation to the NTE procedure.

Analysis of the CO2, NOx emission and fuel consumption from a heavy-duty vehicle designed for carriage of timber

The paper presents the results of measurements of the CO2 and NOx emission and fuel consumption recorded under actual operating conditions of a heavy-duty vehicle designed for loading and carriage of timber. The tests were performed on a specially designed test route that reflected the arrival of the vehicle to the felling site in the forest, the loading process and return to the lumberyard. The route ran through paved (asphalt) and unpaved (forest) portions. Its total length was 8.6 km. An advanced PEMS (Portable Emission Measurement System) device was used for the measurement of the exhaust emissions - SEMTECH DS by Sensors Inc. The paper analyses the CO2 and NOx emission and fuel consumption on all portions of the test route and presents a comparison between the forest and asphalt roads.

The assessment of exhaust system energy losses based on the measurements performed under actual traffic conditions

It is generally acknowledged that energy losses from the exhaust system are approximately 30% of the total losses of energy supplied to the engine in the form of fuel. Part of this energy is used to heat the aftertreatment systems whose pollutant conversion rate is tightly related to their operating temperature. The exhaust gas flowing through the catalytic supports of the converters and filters warms them up while the outstanding energy contained in the gases is lost permanently. Hence, it is vital to recuperate the waste energy and convert it into different forms such as electrical energy using thermoelectric modules. In this paper, we determined the energy loss in an exhaust system of a city bus following the measurements carried out under actual traffic conditions on a regular bus route. The measurements of the exhaust gas temperature and mass flow were performed at three points. For this, thermoresistors and a portable exhaust emission analyzer SEMTECH DS (designed for exhaust emission testing under actual traffic conditions) were used. Based on the measured exhaust emission of CO2, CO and THC we determined the vehicle gas mileage. From the vehicle diagnostic system, we pulled basic data of the engine operation and based on this, the amount of energy supplied to the engine and the losses through the exhaust system throughout the entire test run of the bus were determined.

Environmental Aspects of the Use of CNG in Public Urban Transport

This chapter concerns the problem of assessing the exhaust emission from the engines of city transport buses fuelled by CNG. It presents a comparative analysis of toxic exhaust emissions of CO, HC, NOx and PM, from urban buses powered by diesel and CNG. The measurements were carried out over the SORT standardised cycles as well as during a real drive condition on a city bus route. The research revealed that CNG bus generates significantly lower NOx emission, whereas its CO and HC emissions are higher. Taking into account low PM emissions, CNG buses should be regarded as eco-friendly means of public transport.