Exhaust Gas Analysis Research Articles

Thermal characteristics and exhaust-gas analysis behind bluff-body frustums

Four configurations of frustums (unrifled, inner-rifled, outer-rifled and two-faced rifled) were used to modulate the flow momentum. The rifle configuration transformed the axial flow velocity to radial direction for increasing the turbulence intensity (T.I.). The increased T.I. improved the mixing between the air and fuel flow. Direct photography, Schlieren photography, hot-wire anemometry, thermocouple, and gas analyzer were utilized to measure the flame length, turbulence intensity, flame temperature, heat release, and exhaust-gas concentrations. The Schlieren flame structures show that the lifted flame is dismissed behind the unrifled, inner-rifled, outer-rifled, and two-faced rifled frustums; and therefore, the flame can be further stabilized. Behind the two-faced rifled frustum, the T.I. increased from 0.15% to 4.6% and the non-dimensional flame length (H/D) decreased from 24 to 14 (i.e., a flame shortening of around 42%). The low flame temperature approximately corresponded to the low concentration of nitride oxide (CNO). The high air–fuel mixing (caused by the high T.I.) corresponded to a high total combustion intensity and a low NO.

Combustion and Emission Investigation of Diesel Fuel and Kerosene Blends

This study presents experimental investigation of combustion of diesel fuel, kerosene and their blends. The objective of this study is to determine the combustion performance and gas emission of diesel fuel, kerosene and various mixtures of diesel fuel and kerosene in a horizontally positioned cylindrical furnace. Heat was removed from the system by the use of water around a jacket of the combustion unit. The combustion unit is capable of burning most types of liquid and gaseous hydrocarbon fuels. Results on combustion performance and gas emissions are presented for a wide range of air fuel equivalence ratios. The results of exhaust gas analyses of carbon monoxide, carbon dioxide and oxygen are presented. Combustion efficiency and the effect of blending of fuels on its performance are also presented. In general, some improvements in exhaust gas emission and combustion efficiency were obtained upon using mixtures of fuels. The best results were obtained when a fuel blend of 75% kerosene and 25% diesel was prepared and burned in the unit.

Optical Studies of Dry and Wet Reformed Methane on Solid Oxide Fuel Cell Anodes

The presently limited understanding of solid oxide fuel cell (SOFC) anode mechanisms is due to a lack of experimental techniques that can probe species and component materials directly during operation, or in operando. Previous investigations on the efficiency of Ni-YSZ-based electrode materials in different reforming conditions have been performed using post-mortem and in situ electrochemical analyses with little information on specific mechanisms that lead to fuel oxidation and cell degradation. An ensemble of non-invasive optical methods consisting of near infrared thermal imaging (NIRTI), Raman spectroscopy, and Fourier-transform infrared emission spectroscopy (FTIRES) is utilized to correlate the chemistry of fuel oxidation and carbon formation with traditional electrochemical measurements for methane and simulated biogas fuels in operating SOFCs. Different reforming conditions for methane including plain, wet (steam), and dry (carbon dioxide) are investigated on anode- and electrolyte-supported cells. NIRTI results demonstrate that cooling on the anode surface due to endothermic hydrocarbon cracking for dry reforming or simulated biogas is significantly greater than for unreformed methane on both types of cells. Raman and FTIRES both show that more carbon is deposited with methane than with biogas. The small amount of carbon formed is limited to lower temperatures with simulated biogas whereas carbon formation occurs to a great extent at all temperatures with methane. Exhaust gas analysis with ex situ FTIR absorption measurements and mass spectrometry are combined with in operando measurements to further characterize and quantify the species involved. These findings serve as benchmark data for a better understanding of the mechanisms responsible for performance and degradation of SOFCs.

Analysis of pre-heated crude palm oil, palm oil methyl ester and its blends as fuel in a diesel engine

Diesel engines are widely used in the surface transport system. They are the main source of economic growth of a nation. Nowadays, awareness of the environment compels people to adopt stringent emission norms. The rapid depletion of fossil fuels and the increase in the emission levels have caused concerns globally. An eco-friendly alternate is required to fulfil the growing demand. This paper focuses on alternate fuels and the importance of choosing palm oil. The energy density and higher cetane number are its major advantages. Also it reduces environmental pollution drastically. The viscosity of palm oil is a problem like other vegetable oils, which affects the fuel spray pattern. It reduces the efficiency of the combustion to a large extent. To overcome the problem, the pre-heating technique and transesterification process are adopted in this work. Performance tests were conducted on a single cylinder, four-stroke, direct injection diesel engine coupled with eddy current dynamometer, and emission was monitored using an AVL exhaust gas analyser. The results indicated that vegetable oil fuels have lower brake thermal efficiency compared to that of diesel. Pre-heated oil and methyl ester showed an appreciable reduction in hydrocarbon (HC) and carbon monoxide (CO) emissions and higher exhaust temperature and nitric oxide (NOx) emission.

Artificial neural network approach to predict the engine performance of fish oil biodiesel with diethyl ether using back propagation algorithm

An artificial neural network (ANN) model is developed to predict the engine performance of fish oil biodiesel blended with diethyl ether. Engine performance and emission characteristics such as brake thermal efficiency, hydrocarbon, exhaust gas temperature, oxides of nitrogen (NOx), carbon monoxide (CO), smoke and carbon dioxide (CO2) were considered. Experimental investigations on single-cylinder, constant speed, direct injection diesel engine are carried out under variable load conditions. The performance and emission characteristics are measured using an exhaust gas analyser, smoke metre, piezoelectric pressure transducer and crank angle encoder for different fuel blends and engine load conditions. In this model, a back propagation algorithm is used to predict the performance. Computational results clearly demonstrated that the developed ANN models produced less deviations and exhibited higher predictive accuracy with acceptable determination correlation coefficients of 0.97–1 and mean relative error of 0–3.061% with experimental values. The root mean square errors were found to be low. The developed model produces the idealised results and it has been found to be useful for predicting the engine performance and emission characteristics with limited number of available data.

INFLUENCE OF SPEED AND LOAD ON THE ENGINE TEMPERATURE AT AN ELEVATED TEMPERATURE COOLING FLUID

In this article has been found that the most popular and widely used method of cooling is liquid cooling, which ensures uniformity of temperature around the combustion chamber and easy acquisition and transfer of heat, although the properties of water are limited by maximum temperature of the coolant. Preliminary scientific research of such a system indicates the possibility of increasing overall efficiency and reducing toxic components in exhaust gases at low engine loads when the engine exhaust temperature of the classic system is too low for efficient catalytic action. This paper presents the dynamometer test stand designed and built using original components of diesel engine 4CT90 production of WSW ANDORIA SA. Presented system was designed for the four cylinder with indirect fuel injection system. Research was made on the engine dynamometer stand, which was equipped with standard measure devices (measures: speed, torque, temperatures, flows) and exhaust gas analysers. The temperature of this liquid was increased to the higher level than temperature of boiling water in normal conditions. Overpressure inside the cooling system was limited to 0.3 MPa, the temperature inside the cooling system was increased to 115–120°C. During the test, the cooling system was filled with coolant at 90%. The selected results of investigations of the cooling system for the combustion engine working with higher temperature of the cooling liquid, where the influence of speed and load on the engine temperature were presented.

APPROVAL TESTS AND EVALUATION OF EMISSION PROPERTIES OF VEHICLE

Operation of vehicles equipped with combustion engines is a source of pollution. That is why the emissions from this source are restricted. The emissions reduction system consists of several steps, whose basic component is a typeapproval of vehicle in terms of emissions level and admission to the registration of vehicles that meets the requirements for emissions. It is assumed, that the gradual reduction of emissions limits will improve the emission properties of the vehicles, and gradual withdrawal of used vehicles, will reduce of emissions growth. The basis for issuing opinions on a vehicle's exhaust emissions is the measurement of emissions performed in the laboratory on a chassis dynamometer in reproducible conditions of preparing the vehicle for testing, test replication, fuel for the engine, and the procedure for collecting the exhaust gas analysis. Motor Transport Institute conducts the type approval tests, as well as the research on emissions from vehicles in the real traffic conditions, which are used to determine the actual emission from the vehicle population. Emission tests for applications, that go beyond the application of type approval show, that there are vehicles whose emissions in operation is substantially different from the emissions measured during type approval. It is a natural phenomenon in the case of used vehicles and vehicles with engine malfunctions or exhaust aftertreatment system defect. However, there are vehicles whose emissions under specific operating traffic conditions are significantly different from the values obtained in the course of type approval tests, despite the good properties of emission measured under the conditions provided by the type-approval procedure. The article discusses the results of the emissions from vehicles, obtained in the tests used to determine the emission factors for vehicles used in real traffic conditions, thus taking into account emissions from vehicles, made under different conditions than the type approval tests, which show that, in terms of driving cycles, which are not covered by the emission test procedure, can multiply and exceed the approved values.. This is particularly true for modern diesel engines.

Exhaust emission test performance with the use of the signal from air flow meter

The paper presents selected technical solutions in the area of exhaust emissions research conducted in real operational conditions of a vehicle. The author describes his own road emissions research methodology with the use of information about the air flow supplying an engine (OBD II) and the measured volumetric shares of particular fumes components (exhaust gas analyser). Test results confirm the possibility of applying this measurement method, and their analysis shows the inadequacy of the type-approval tests compared to the real operation of the vehicle.

Thermochemical recovery technology for improved modern engine fuel economy – part 1: analysis of a prototype exhaust gas fuel reformer

Exhaust gas fuel reforming has the potential to improve the thermal efficiency of internal combustion engines, as well as simultaneously reduce gaseous and particulate emissions.

Combustion characteristics of premixed propane flame with added H2 and CO on a V-shaped impinging burner

The combustion characteristics of H2/C3H8/air and CO/C3H8/air premixed flames on a V-shaped burner have been investigated experimentally for future blended fuels with flow visualization, chemiluminescence and analysis of exhaust gases. The lean flammability of H2/C3H8/air is expanded to 0.38 and that of CO/C3H8/air is expanded to 0.50 on the V-shaped burner. The flame configurations, flow structures, distributions of chemiluminescence intensity of CH* and OH*, flame temperatures and CO emissions under varied mixture conditions were recorded during the combustion. Two flame configurations were observed – of types M and hill. The addition of H2 and CO to the fuel altered the flame pattern from hill-type to M-type (shorter flame) because the burning velocity, temperature and flame intensity increased with the addition of H2 and CO in the fuel. Analysis of flow visualization and chemiluminescence revealed the impinging effect, in which the collision of mixture jets decreases the main flow velocity and increases the residence time. It results in a greatly decreased leakage of the unburned mixture with accumulated heat acting as a well stirred combustible mixture for improved flame stabilization. At ɸ = 0.6, the flame temperature of H2/C3H8/air with M-type flame is 1.37 times that of CO/C3H8/air with hill-type flame, while the C3H8/air flame is extinguished. The combustion of CO that occurs in the impinging region resulted in decreased CO emissions when the addition of CO to the fuel surpassed 73.7%. These findings about the combustion characteristics, mechanisms and effects of fuel variability provide industries with an effective concept of burning blended fuels, and are applicable to syngas combustion.

Non-invasive monitoring of bacterial growth and auto-induced protein production in a bioreactor with a closed-loop GC-IMS

In numerous applications biomass or biochemically active substances, like pharmaceuticals, flavors or bio-ethanol, are produced in industrial-scale bioreactors. In order to ensure a constant and high quality and quantity of the particular product the biochemical environment within the reactor needs to be continuously controlled within narrow limits. Thus, sensitive sensor systems that allow continuous and preferably non-invasive monitoring of relevant parameters during the cultivation are required. In this work we present results of an analysis of exhaust gas of a bioprocess composed of growing phase and auto-inductive protein production phases of a recombinant Escherichia coli BL21 strain as model organism using a compact closed-loop ion mobility spectrometer (IMS) with gas chromatographic (GC) pre-separation. The used GC-IMS (in-house development) has a mobility resolution of about R = 90 (IMS drift time / peak width) and enables automatic sampling and analysis of the exhaust gas every 20 min. We compare the intensity of different IMS peaks with additional online and offline data like oxygen consumption, optical density or the fluorescence of a GFP-labeled protein which is produced by the organism after auto-induction. A great challenge in this context is to detect trace concentrations of possible precursors for a metabolic change or indicators for the efficiency of such a change in the presence of very high concentrations of water and compounds like acetone, ethanol and ammonia. Besides multiple peaks that show a significant and reproducible change during the cultivation we observe at least one peak that is assumed to be a precursor for the induction process.

Effect of gasoline/methanol blends on motorcycle emissions: Exhaust and evaporative emissions

The emission characteristics of motorcycles using gasoline and M15 (consisting of 85% gasoline and 15% methanol by volume) were investigated in this article. Exhaust and evaporative emissions, including regulated and unregulated emissions, of three motorcycles were investigated on the chassis dynamometer over the Urban Driving Cycle (UDC) and in the Sealed Housing for Evaporative Determination (SHED), respectively. The regulated emissions were detected by an exhaust gas analyzer directly. The unregulated emissions, including carbonyls, volatile organic compounds (VOCs) and methanol, were sampled through battery-operated air pumps using tubes coated with 2,4-dintrophenylhydrazine (DNPH), Tenax TA and silica gel, respectively. The experimental results showed that, for exhaust emission, compared with those from gasoline fueled motorcycles, the concentration of total hydrocarbons (THC) and CO from motorcycles fueled with M15 decreased by 11%–34.5% and 63%–84% respectively, while the concentration of NOx increased by 76.9%–107.7%. Compared with those from gasoline fueled motorcycles, BTEX from motorcycles fueled with M15 decreased by 16%–60% while formaldehyde increased by 16.4%–52.5%. For evaporative emission, diurnal losses were more than hot soak losses and turned out to be dominated in evaporative emissions. In addition, compared with gasoline fueling motorcycles, the evaporative emissions of THC, carbonyls and VOCs from motorcycles fueled with M15 increased by 11.7%–37%, 38%–45% and 16%–42%, respectively. It should be noted that the growth rate of methanol was as high as 297%–1429%. It is important to reduce the evaporative emissions of methanol fueling motorcycles.

Exhaust and evaporative emissions from motorcycles fueled with ethanol gasoline blends

The emission characteristics of motorcycles using gasoline and E10 (90% gasoline and 10% ethanol by volume) were investigated in this article. Exhaust and evaporative emissions of three motorcycles were investigated on the chassis dynamometer over the Urban Driving Cycle (UDC) and in the Sealed Housing for Evaporative Determination (SHED) including regulated and unregulated emissions. The regulated emissions were detected by an exhaust gas analyzer directly. The unregulated emissions including carbonyls and volatile organic compounds (VOCs) were sampled through battery-operated air pumps using tubes coated with 2,4-dinitrophenylhydrazine (DNPH) and Tenax TA, respectively. The experimental results showed that the emission factors of total hydrocarbons (THC) and carbon monoxide (CO) from E10 fueling motorcycles decreased by 26%–45% and 63%–73%, while the emission factor of NOx increased by 36%–54% compared with those from gasoline fueling motorcycles. For unregulated emissions, the emission amount of VOCs from motorcycles fueled with E10 decreased by 18%–31% while total carbonyls were 2.6–4.5 times higher than those for gasoline. For evaporative emissions of THC and VOCs, for gasoline or E10, the diurnal breathing loss (DBL) was higher than hot soak loss (HSL). Using E10 as a fuel does not make much difference in the amount of evaporative THC, while resulted in a slightly growth of 14%–17% for evaporative BETX (benzene, toluene, ethylbenzene, xylene).

VLIV POUŽÍVÁNÍ BIOPALIV NA PROVOZNÍ PARAMETRY SPALOVACÍCH MOTORŮ TRAKTORŮ

Application of alternative fuels brings the social benefits in terms of reducing dependence on oil industry and its products as well as decreasing of damage of the environment together with using of na­tu­ral resources, especially in field of renewable energy resources. The use of biofuels is the most important part of energy strategy in European Union, whose member states have agreed the content of biofuels will achieve 5.75% of the total energy sum of fuel for transport purposes in 2010. Operation of internal combustion engine fueled by RME brings environmental benefits as described several authors in analysis of the life cycle. The contribution deals with technical difficulties of the RME usage in internal combustion engine used in agricultural tractors. Different fuel causes different process of combustion which means changes in output power and pollution. The aim of this experiment was to determine these effects. Experimental work was divided into two parts according to various fuel systems. The first tractor was equipped with mechanical injection system, the second one was provided with common-rail fuel system. The test procedures consisted of measurement of power- torque curves where the engine load was created by Eddy current dynamometer. Exhaust gas analyzer sampled the pollution of carbon monoxide, carbon dioxide and hydrocarbons as the most important indicators of combustion process.

Part-load performance and emissions of a spark ignition engine fueled with RON95 and RON97 gasoline: Technical viewpoint on Malaysia’s fuel price debate

Due to world crude oil price hike in the recent years, many countries have experienced increase in gasoline price. In Malaysia, where gasoline are sold in two grades; RON95 and RON97, and fuel price are regulated by the government, gasoline price have been gradually increased since 2009. Price rise for RON97 is more significant. By 2014, its per liter price is 38% more than that of RON95. This has resulted in escalated dissatisfaction among the mass. People argued they were denied from using a better fuel (RON97). In order to evaluate the claim, there is a need to investigate engine response to these two gasoline grades. The effect of gasoline RON95 and RON97 on performance and exhaust emissions in spark ignition engine was investigated on a representative engine: 1.6L, 4-cylinder Mitsubishi 4G92 engine with CR 11:1. The engine was run at constant speed between 1500 and 3500rpm with 500rpm increment at various part-load conditions. The original engine ECU, a hydraulic dynamometer and control, a combustion analyzer and an exhaust gas analyzer were used to determine engine performance, cylinder pressure and emissions. Results showed that RON95 produced higher engine performance for all part-load conditions within the speed range. RON95 produced on average 4.4% higher brake torque, brake power, brake mean effective pressure as compared to RON97. The difference in engine performance was more significant at higher engine speed and loads. Cylinder pressure and ROHR were evaluated and correlated with engine output. With RON95, the engine produces 2.3% higher fuel conversion efficiency on average but RON97 was advantageous with 2.3% lower brake specific fuel consumption throughout all load condition. In terms of exhaust emissions, RON95 produced 7.7% lower NOx emission but higher CO2, CO and HC emissions by 7.9%, 36.9% and 20.3% respectively. Higher octane rating of gasoline may not necessarily beneficial on engine power, fuel economy and emissions of polluting gases. Even though there is some advantage using RON97 in terms of emission reduction of CO2, CO and HC, the 38% higher price and higher NOx emission is more expensive in the long run. Therefore using RON95 is economically better and environmentally friendlier. The findings provide some techno-economic evaluation on the fuel price debate that surround the Malaysia’s population in the recent years. The increased of fuel price may have limited their ability to use higher octane gasoline but it did not negatively affecting the users as they perceive.

Application of fuzzy logic in internal combustion engines to predict the engine performance

This paper describes an application of fuzzy logic principle for predicting the internal combustion engine performance, emission and combustion characteristics using fish oil biodiesel. Experimental investigations on a single cylinder, constant speed, direct injection diesel engine were carried out under variable load conditions. The performance, emission and combustion characteristics such as brake thermal efficiency, hydrocarbon, exhaust gas temperature, oxides of nitrogen (NOx), carbon monoxide, smoke, carbon dioxide, ignition delay, combustion delay and maximum rate of pressure rise were considered. Engine performance was measured using an exhaust gas analyser, smoke metre, piezoelectric pressure transducer and crank angle encoder for different fuel blends and engine load conditions. The obtained data were recorded for each experiment and associated data used to develop a multiple inputs and multiple outputs fuzzy logic model. The developed model produced idealised results with the correlation coefficients of 0.988–0.999 and root mean square error, and was found to be useful for predicting the engine performance characteristics with limited number of available data.

Combustion process shaping by use of different strategies of multiple fuel injection in a CI model engine

Technological advancement in combustion systems of diesel engines triggers the need of fulfilling many contradictory requirements. Among those are such issues as maintenance of environmental standards in terms of the exhaust emissions with a simultaneous preservation of the thermodynamic properties of the combustion process and fuel consumption. The paper discusses the results of research on the influence of the strategies of fuel dose division on the combustion process and operational indexes in a model engine. The paper also contains an exhaust gas analysis conducted with the use of a rapid compression machine. The investigations of the combustion process (development of the self-ignition spots) were conducted using high speed camera. The recorded images related to the period from the onset of the injection to the beginning of the appearance of combustion spots have also been analyzed. The following have been varied: number of doses, size of doses, dwell times and excess air coefficient. The authors performed a comparative analysis of the thermodynamic indexes of the combustion process obtained from the indicator tracings. The achieved results show possibilities of the influencing on the combustion process course and emission of exhaust toxic compounds by application of multiple injection and its properly selected strategy containing proportions in fuel doses and dwell times between them.

Exhaust gas analysis and formation mechanism of SiC nanowires synthesized by thermal evaporation method

Silicon carbide nanowires (SiCNWs) are a set of promising reinforcement materials due to their superior properties. However, formation mechanism of the SiCNWs synthesized by the thermal evaporation method without metal catalyst is still unclear. To understand the formation mechanism, SiCNWs were synthesized by the thermal evaporation method at 1350 °C using a pre-oxidized Si powder and CH4 gas as precursors. SiCNWs obtained by this method were β-SiC/SiO2 core–shell nanowires with average diameter about 55 nm and with a length up to 1 mm. The exhaust gases during the SiCNWs synthesis process were examined by gas chromatography and the photographs of growth activity of SiCNWs inside the furnace were captured. CO gas was detected during the active formation of SiCNWs. It was clarified that CO gas was one of the byproducts from SiCNWs synthesis process, and the formation reaction of SiCNWs should be 3SiO(g) + 3C(s) → 2SiC(s) + SiO2(s) + CO(g). The formation of SiCNWs was discussed based on the oxide-assisted-growth mechanism.

The Turbocharger Exhaust Gas Regulator Design and Analysis

In order to adapt to the needs of internal combustion engine speed variation of the turbocharger. Using waste gas regulator control exhaust gas inlet device. The effect of exhaust gas regulator is for adjusting the gas flow velocity and direction. When the internal combustion engine running at low speed raising the impeller speed. Exhaust gas regulator and axial moving blades rotating blades of two kinds of structure. The axial moving blade structure is changing the way nozzle ring opening work. Rotating blade structure is working on changing the way of blade Angle. Exhaust gas to adjust the turbocharger is a control of internal combustion engine air pressurization value of the speed changes.

Effects of the sulfur content of liquefied petroleum gas on regulated and unregulated emissions from liquefied petroleum gas vehicle

A more stringent standard for sulfur in liquefied petroleum gas (LPG) is currently being considered by the Ministry of Environment of Korea. Therefore, we investigated the characteristics of exhaust emissions from liquid phase LPG injection passenger car depending on the sulfur content of the LPG. Using a chassis dynamometer test with exhaust gas analyzers and Fourier-transform infrared spectroscopy, regulated emissions of carbon monoxide, non-methane hydrocarbons, and nitrates were investigated, as well as unregulated emissions of CH4, N2O, NH3, and SO2. Vehicle tests were carried out using Federal Test Procedure 75 (FTP-75) and Highway Fuel Economy Test (HWFET) cycles and time-resolved exhaust emissions and mass emissions were analyzed. The concentrations of regulated and unregulated time-resolved emissions increased during the cold start phase (Phase 1) of the FTP-75 cycle, in which the catalyst does not reach the light-off temperature. In the FTP-75 and HWFET cycles, most of the regulated and unregulated mass emissions increased as the sulfur content of the LPG increased. The SO2 concentration in the emissions increased in proportion to the sulfur content in the LPG, particularly in the high-speed portion of the FTP-75 cycle.