Analysis of exhaust emission processes during the Real Driving Emissions test

The article deals with the study of exhaust emissions from a combustion engine in the Real Driving Emission (RDE) test. These tests are a simulation of real conditions of use of motor vehicles. Nowadays, RDE tests are mandatory for Light Duty Vehicle (LDV) and Heavy Duty Vehicle (HDV) vehicles and in the future, restrictive standard. Euro 7, which combines stricter limits with a comprehensive RDE test cycle, is becoming a challenge for current vehicle engineering. The paper presents the results of pollutant emission tests from a passenger car (PC). In the tests of LDV in the RDE test, the results of which are analyzed in the article, the Portable Emissions Measurement System (PEMS) mobile exhaust emission testing system was used. The processes describing the operating states of the vehicle and the combustion engine, as well as the processes of exhaust emission intensity and the intensity of the number of particulate (PN), were examined. The correlation between the considered processes was investigated. The emission of carbon monoxide, hydrocarbons, nitrogen oxides, particulate and carbon dioxide as well as the road PN were examined. The zero-dimensional statistical characteristics of the examined processes were also determined. The probability density and power spectral density of the processes were established. A great diversity was found in the properties of the process distributions, as well as in the dynamic properties of the processes. In the summary of the analysis of the results of the car speed process, the operating states of the combustion engine and the processes of exhaust emission intensity and the process of the intensity of PN in the RDE test, conclusions were formulated regarding, among others, course of the intensity of these compounds, correlation of the processes of pollution emission intensity and the intensity of the PN with the process of car speed, distribution of processes

Determination of exhaust emission characteristics in the RDE test using the Monte Carlo method

The article presents a method of determining the characteristics of exhaust emissions and fuel mass consumption in real driving conditions based on a single test using the Monte Carlo method. The exhaust emission characteristics used are the relations between the emissions and the average vehicle speed, and the characteristic of the fuel mass consumption is the dependence of the fuel mass consumption at the average vehicle speed. The results of empirical research of a passenger car with a spark-ignition engine in the RDE test were used. The use of the Monte Carlo method made it possible to select the initial and final moments of averaging the process values, thanks to which it was possible to determine the discrete values of the characteristics for various values of average vehicle speeds. The determined discrete characteristics of the particulate mass and number emissions and fuel mass consumption relative to the average vehicle speed were approximated by polynomial functions of the second and third degree. The determined discrete characteristics, presented as sets of points, were characterized by a relatively small dis-persion in relation to their polynomial approximations. The average relative deviation of the points of discrete characteristics from the value of the polynomial was in most cases small less than 4%, only in the case of the number of particles emitted deviated from this, as the average relative deviation of the measured points from the determined polynomial was nearly 14%. Combined with the results of RDE empirical studies, the Monte Carlo method proved to be an effective method for determining the characteristics of exhaust emissions, measured in real vehicle operating conditions. The main advantage of the proposed method was a significant reduction in the actual workload necessary to carry out the empirical research where it became possible to determine the charac-teristics in a large range of vehicle average speed values with just one drive test. Using standard methods of meas-uring this type of data, it would be necessary to conduct multiple tests, driving at different average vehicle speeds

Assessment of the Internal Catalyst Efficiency in a Diesel Engine of a Vehicle under the Conditions Simulating Real Driving

The application of a catalyst on a surface inside a combustion chamber is known as a supplementary method of exhaust gas aftertreatment. The efficiency of this method in the reduction in exhaust emissions as well as its influence on other engine properties has been analyzed in multiple scientific works. Most often, these works present the results of investigations carried out on dynamometers under engine stationary conditions. There are no results of the catalyst investigations performed under dynamic states, particularly on-going real time analyses during engine operation. Therefore, the authors set out to explore the efficiency of the in-cylinder catalyst of a diesel engine under dynamic conditions simulating actual vehicle operation. A unique methodology was applied. The investigations were carried out in road conditions in a test simulating the New European Driving Cycle (NEDC) homologation test in compliance with the similarity criteria of the zero-dimensional characteristics of vehicle speed during the investigations and in the homologation test. For the research, the authors used portable exhaust emissions measurement equipment. A unique method of test results analysis was also applied (a continuous method in the time domain). As a result of the tests being repeated several times, it was observed that the application of an internal catalyst under different operating engine conditions repeatedly results in: an approx. 2% reduction in the emissions of carbon monoxide, hydrocarbons, and carbon dioxide; a similar increase in the emission of nitrogen oxides; and a significant (over 10%) reduction in the particle number. The obtained results substantiate the purpose of actions aiming at improving the efficiency of the internal catalyst

Simulation tests of selected gas flow parameters through combustion engine valves

The article presents the numerical analysis of a single-cylinder gasoline engine with indirect injection and spark ignition. The goal is to recognize and analyze gas flow through inlet and outlet valves and channels. These data were obtained from the simulation of a four-cycle engine cycle without combustion of the fuel-air mixture. The simulation was carried out in ANSYS, using a dedicated IC Engine module. After the simulation, the result was analyzed on the cross-sectional plane of both the valves and the combustion chamber. This method provided the necessary and concise representation of the flow characteristics. Five separate stages are presented – two describing the different displacement of the valve for each inlet and exhaust stroke and one representing the phenomenon of overlapping. The type of flow, its speed and tendency to create turbulence are described

The influence of internal catalyst on exhaust emission in dynamic conditions

The article discusses the use of an internal catalyst, which allows to reduce the emission of harmful compounds during internal combustion engine operation. This is a type of exhaust aftertreatment system; however, its placement inside the combustion chamber, and thus closest to the combustion process, allows reducing the pollution at the source (the catalyst was sprayed on the glow plugs). This is necessary because vehicle pollution reduction is a key aspect of reducing the negative environmental impact of transport. The presented research results are a part of a wider research scheme, on the evaluation of the internal catalyst impact in various engine operating conditions – starting from static tests (on an engine dynamometer), through dynamic dynamometer tests, and ending with vehicle road tests in real driving conditions. The use of an internal catalyst during dynamic tests results in a few percent reduction in the mass of carbon monoxide, hydrocarbons, carbon dioxide and the number of particulates in the considered measurement test. It is technically possible to introduce this kind of a technical solution in most vehicles with Diesel engines, thus resulting in improved ecological properties of internal combustion engines

Influence of the Length of a Catalyst-Coated Glow Plug on Exhaust Emissions

This paper discusses the application of an in-cylinder catalyst in reducing the exhaust emissions from a diesel engine. This is an additional method of exhaust gas aftertreatment; yet the placement of a catalyst in the combustion chamber (i.e., the closest location to the process of combustion) allows a reduction of the emissions ‘at source’ (the catalyst applied on the glow plugs). For the investigations, we used an engine dynamometer to reproduce the traffic conditions of a homologation test carried out on a chassis dynamometer. We carried out the investigations on a Euro 4 1.3 JTD MultiJet diesel engine. The selection of the research object was followed by an analysis of the number of engines used in the EU meeting individual emission standards. We present results (measurement of carbon monoxide, hydrocarbons, nitrogen oxides, particle number, and carbon dioxide) related to the assessment of the applicability of the in-cylinder catalyst for three types of glow plugs: standard, catalyst-covered, and a prototype plug with an elongated catalyst-covered heating part. Prototype catalytic glow plugs ensure a few percent reduction in the emission of carbon monoxide, hydrocarbons, carbon dioxide, and particle number. The use of such a solution (glow plug replacement) in most diesel engines (easy to retrofit) would improve the environmental performance of combustion engines. It is of particular importance that in-cylinder catalysts are most efficient during cold start and warm-up, which is often the case in urban driving

CFD analysis of the Ferrari 348 GTC intake system

The article presents CFD (Computational Fluid Dynamics) analysis of the intake system of a Ferrari 348 GTC sports car. With this system, an adequate amount of air is supplied relative to the current demand for fuel combustion. The air demand of a given engine was determined, then analyzes were carried out. The article contains an analysis of the velocity distribution: total velocities, angular velocities and static pressure distribution. In addition, local velocity and flow in the filtration chamber were determined along with the flow directions and returns as well as power lines. The cycle impact on the temperature, locations of the highest speed drop, increase in turbulence, the largest pressure differences, and modulus of elasticity were determined. This information allows to assess whether there are no unwanted phenomena occurring in the system, such as flow disturbances. The Ansys Fluent software was used for analysis.W artykule przedstawiono analizę CFD (Computational Fluid Dynamics) układu dolotowego samochodu sportowego Ferrari 348 GTC. W tym systemie dostarczana jest odpowiednia ilość powietrza w stosunku do bieżącego zapotrzebowania na spalanie paliwa. Określono zapotrzebowanie na powietrze dla danego silnika, a następnie przeprowadzono analizy. Artykuł zawiera analizę rozkładu prędkości: prędkości całkowite, prędkości kątowe i rozkład ciśnienia statycznego. Dodatkowo wyznaczono lokalną prędkość i przepływ w komorze filtracyjnej wraz z kierunkami przepływu i powrotami oraz liniami energetycznymi. Oceniono wpływ cyklu na temperaturę, lokalizację największego spadku prędkości, wzrost turbulencji, największe różnice ciśnień i moduł sprężystości. Informacje te pozwalają ocenić, czy w systemie nie występują niepożądane zjawiska, takie jak zakłócenia przepływu. Do analizy wykorzystano oprogramowanie Ansys Fluent

Analiza CFD układu dolotowego Ferrari 348 GTC

The article presents CFD (Computational Fluid Dynamics) analysis of the intake system of a Ferrari 348 GTC sports car. With this system, an adequate amount of air is supplied relative to the current demand for fuel combustion. The air demand of a given engine was determined, then analyzes were carried out. The article contains an analysis of the velocity distribution: total velocities, angular velocities and static pressure distribution. In addition, local velocity and flow in the filtration chamber were determined along with the flow directions and returns as well as power lines. The cycle impact on the temperature, locations of the highest speed drop, increase in turbulence, the largest pressure differences, and modulus of elasticity were determined. This information allows to assess whether there are no unwanted phenomena occurring in the system, such as flow disturbances. The Ansys Fluent software was used for analysis.W artykule przedstawiono analizę CFD (Computational Fluid Dynamics) układu dolotowego samochodu sportowego Ferrari 348 GTC. W tym systemie dostarczana jest odpowiednia ilość powietrza w stosunku do bieżącego zapotrzebowania na spalanie paliwa. Określono zapotrzebowanie na powietrze dla danego silnika, a następnie przeprowadzono analizy. Artykuł zawiera analizę rozkładu prędkości: prędkości całkowite, prędkości kątowe i rozkład ciśnienia statycznego. Dodatkowo wyznaczono lokalną prędkość i przepływ w komorze filtracyjnej wraz z kierunkami przepływu i powrotami oraz liniami energetycznymi. Oceniono wpływ cyklu na temperaturę, lokalizację największego spadku prędkości, wzrost turbulencji, największe różnice ciśnień i moduł sprężystości. Informacje te pozwalają ocenić, czy w systemie nie występują niepożądane zjawiska, takie jak zakłócenia przepływu. Do analizy wykorzystano oprogramowanie Ansys Fluent

The influence of the heating time of a catalyst-covered glow plug on the exhaust emissions from a diesel engine

The paper discusses the application of an in-cylinder catalyst allowing a reduction of the exhaust emissions from a diesel engine. Its placement in the combustion chamber, the area where the process of combustion takes place, allows reducing the emissions (carbon monoxide, hydrocarbons, particulate matter) ‘at source’. The paper presents the possibilities of boosting the efficiency of catalysts in diesel engines by extending the time of heating of a glow plug (the catalyst applied on the glow plug). The tests were performed for the following conditions: no heating (marked 0+0), glow plug heating for 60 s after engine start (marked 0+60), glow plug heating prior to engine start for 60 s and glow plug heating for 60 s after engine cold start (marked 60+60). An improvement in the efficiency of oxidation of the exhaust components was observed as the glow plug heating time increased

Evaluation of the correlation between concentration of volatile organic compounds and temperature of the exhaust gases in motor vehicles

Volatile organic compounds (VOCs) are the group of organic compounds which are one of the most important air pollutants. One of the main sources of VOCs are combustion processes including fuel combustion is internal combustion engines. Volatile organic compounds are very dangerous pollution, because even in very low concentrations they have significant harmful effect on human health. A lot of that compounds are mutagenic and carcinogenic, in addition they could cause asthma, intoxication or allergy. The measurements of VOCs are quite problematic, because it is required using the specialist analytical apparatus, ex. chromatograph. However, not always it is need to measure the content of that compounds in engine exhaust with high precision and sometimes it is enough only to estimate the level of the concentration. Emission of the VOCs mainly depends on the combustion process in the engine and this determines the temperature of the exhaust gases. In this paper authors tried to determine if the correlation between temperature of exhaust gases and VOCs' concentration exist and is able to determine