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1
Korczewski, Zbigniew. "Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part I Standard Measurements". Polish Maritime Research 22, n. 1 (1 gennaio 2015): 47–54. http://dx.doi.org/10.1515/pomr-2015-0007.
Testo completoAbstract (sommario):
Abstract The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple. The first part of the article discusses possibilities to perform diagnostic inference about technical condition of a marine engine with pulse turbocharging system based on standard measurements of exhaust gas temperature in characteristic control cross-sections of its thermal and flow system. Selected metrological issues of online exhaust gas temperature measurements in those engines are discusses in detail, with special attention being focused on the observed disturbances and thermodynamic interpretation of the recorded measuring signal. Diagnostic informativeness of the exhaust gas temperature measurements performed in steady-state conditions of engine operation is analysed in the context of possible evaluations of technical condition of the engine workspaces, the injection system, and the fuel delivery process.
2
Korczewski, Zbigniew. "Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part II Dynamic Measurements". Polish Maritime Research 23, n. 1 (1 gennaio 2016): 68–76. http://dx.doi.org/10.1515/pomr-2016-0010.
Testo completoAbstract (sommario):
Abstract The second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy) in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment of the enthalpy flux of successive pressure pulses of the exhaust gas supplying the marine engine turbocompressor. General design assumptions are presented for the measuring and diagnostic system which makes use of a sheathed thermocouple installed in the engine exhaust gas manifold. The corrected thermal inertia of the thermocouple enables to reproduce a real time-history of exhaust gas temperature changes.
3
Korczewski, Zbigniew. "Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines". Polish Maritime Research 18, n. 4 (1 gennaio 2011): 49–53. http://dx.doi.org/10.2478/v10012-011-0026-7.
Testo completoAbstract (sommario):
Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines The third part of the article presents a method for detecting failures of the automatic engine control system with the aid of an exhaust gas temperature setter, specially designed and machined for this purpose. It also presents a procedure of identifying the operating tolerances and determining the diagnostic tolerances for the exhaust gas temperature recorded in the naval turbine engine during the start-up and acceleration processes. The diagnostic tolerances were determined using the statistic inference, based on the hypothesis about the normal distribution of the starting exhaust gas temperature dispersion at the initial time of engine operation. The above hypothesis was verified using the non-parametric statistic test χ2 for examining the consistency of the empirical distribution with the assumed normal distribution. As a result of the examination, satisfactory convergence of the compared distributions was obtained which made the basis for assuming the three-sigma limits of the diagnostic tolerance for the analysed engine control parameter.
4
Winnes, Hulda, Erik Fridell e Jana Moldanová. "Effects of Marine Exhaust Gas Scrubbers on Gas and Particle Emissions". Journal of Marine Science and Engineering 8, n. 4 (24 aprile 2020): 299. http://dx.doi.org/10.3390/jmse8040299.
Testo completoAbstract (sommario):
There is an increase in installations of exhaust gas scrubbers on ships following international regulations on sulphur content in marine fuel from 2020. We have conducted emission measurements on a four-stroke marine engine using low sulphur fuel oil (LSFO) and heavy fuel oil (HFO) at different steady state engine loads. For the HFO the exhaust was probed upstream and downstream of an exhaust gas scrubber. While sulphur dioxide was removed with high efficiency in the scrubber, the measurements of particle emissions indicate lower emissions at the use of LSFO than downstream of the scrubber. The scrubber removes between 32% and 43% of the particle mass from the exhaust at the HFO tests upstream and downstream of the scrubber, but levels equivalent to those in LSFO exhaust are not reached. Decreases in the emissions of polycyclic aromatic hydrocarbons (PAH-16) and particulate matter as black carbon, organic carbon and elemental carbon, over the scrubber were observed for a majority of the trials, although emissions at LSFO use were consistently lower at comparable engine power.
5
Damm, Christopher J., Donald Lucas, Robert F. Sawyer e Catherine P. Koshland. "Real-Time Measurement of Combustion Generated Particles with Photofragmentation-Fluorescence". Applied Spectroscopy 55, n. 11 (novembre 2001): 1478–82. http://dx.doi.org/10.1366/0003702011953892.
Testo completoAbstract (sommario):
Excimer laser fragmentation-fluorescence spectroscopy (ELFFS) is a viable technique for real-time monitoring of carbonaceous particles in combustion exhausts. The exhaust from a single-cylinder two-stroke engine is diluted and diverted into the laser interrogation region, resulting in a particle concentration of approximately 1 × 107/cm3. Light from a 193 nm ArF laser photofragments the particles and then produces fluorescence from the atomic carbon fragments at 248 nm, CH fragments at 431 nm, and C2 fragments at 468 nm. The atomic carbon fluorescence signal is proportional to the number concentration of particles in the laser interrogation region. The 100-shot (1 s) detection limit for particles in the exhaust is 1 mg/m3, expressed as a mass concentration of particulate matter. Interferences from carbon monoxide and carbon dioxide are negligible. The relative fluorescence yield at 248 nm is four times greater from particles than from the gas phase hydrocarbons present in the exhaust. This high yield suggests that the gas phase hydrocarbon interference would not be problematic for measurements of diesel exhaust, where the ratio of particulate carbon to gas phase hydrocarbon is high.
6
PUZDROWSKA, Patrycja. "Identification of damages in the inlet air duct of a diesel engine based on exhaust gas temperature measurements". Combustion Engines 177, n. 2 (1 maggio 2019): 108–14. http://dx.doi.org/10.19206/ce-2019-219.
Testo completoAbstract (sommario):
The temperature of the exhaust gas of a diesel piston engine, measured in the characteristic control sections of its thermo-flow system, can be a valuable source of diagnostic information about the technical condition of the elements limiting the working spaces thus separated, including the turbocharging system, but also its fuel supply system and replacement of the medium. In standard marine engine measurement systems equipped with an impulse turbocharging system, the exhaust gas temperature is measured at the outlet of individual cylinders and before and after the turbocharger turbine, using traditional thermocouples with high measurement inertia (time constant of tenths of a second and more). This means that for further diagnostic analyses, the average value of the periodically changing temperature of the exhaust stream leaving individual engine cylinders, the exhaust stream in the collective duct feeding the turbine and the exhaust stream in the exhaust duct of the turbine is used. This article proposes a new approach to the issue of diagnostic informationiveness of the exhaust gas temperature of a diesel engine, extending its observations with the dynamics of changes in the duration of one working cycle. The aim of the tests carried out on the laboratory stand of Farymann Diesel engine type D10 was to determine the diagnostic relations between the loss of permeability of the inlet air channel filter baffle and selected standards of the quick-changing signal of the exhaust gas temperature. On the basis of the calculations carried out, the following dynamic features of the recorded signal were determined: maximum amplitude of instantaneous exhaust gas temperature values (peak-to-peak value), its rate of increase and decrease, and the specific enthalpy of exhaust gases within one engine work cycle. Comparative analysis of numerical data characterizing the recorded quick-changing exhaust gas temperature courses clearly indicates obvious thermodynamic and energy consequences of partial loss of flow capacity of the air channel supplying the combustion chamber of the test engine. A further development of the experimental test programme is foreseen in order to determine a diagnostic matrix to support the diagnostic inference about the technical condition of the diesel engine on the basis of measurements and analysis of the quick-changing exhaust gas temperature.
7
Kang, Il-seok, e Sung-mo Yang. "The Effect of Back Pressure Change on Exhaust Emissions According to the Confluence Geometry of a Dual Exhaust System in Idling". Applied Sciences 12, n. 4 (11 febbraio 2022): 1855. http://dx.doi.org/10.3390/app12041855.
Testo completoAbstract (sommario):
In this study, a pressure transducer was installed in an exhaust system to analyze the effect of the change in back pressure according to the change of the confluence geometry of an exhaust pipe system on an exhaust emission. In addition, to perform exhaust gas measurement, the system was warmed up for about 40 s on the chassis dynamometer, and exhaust gas and back pressure measurements were performed simultaneously. In the back pressure measurement results, it was possible to confirm the difference in back pressure according to the change in the confluence shape. In addition, it was also confirmed that there was a clear difference in the exhaust emission measurement result. In particular, the H-type exhaust pipe system showed the highest pressure in the exhaust pipe due to the influence of the confluence geometry. Due to this influence, THC showed the highest measured value in the exhaust emission result. However, the X-type exhaust pipe system showed the lowest pressure due to the influence of the confluence geometry. Due to this influence, the THC showed the lowest measured value in the exhaust emission result. Therefore, through the conclusion of this study, an optimal exhaust system to reduce THC was proposed, and the importance of back pressure in exhaust system design was confirmed.
8
SUZAKI, Kotaro, Hiroyuki YAMADA, Yuichi GOTO, Kentaro MISAWA, Jun MATSUMOTO, Yohei YAMATO, Shunichi ISHIUCHI et al. "EM2-2: Time-Resolved Measurements of Aromatic Hydrocarbon in Exhaust Gas Using Resonance Enhanced Multi-Photon Ionization Method(EM: Exhaust Emission Control and Measurement,General Session Papers)". Proceedings of the International symposium on diagnostics and modeling of combustion in internal combustion engines 2008.7 (2008): 725–30. http://dx.doi.org/10.1299/jmsesdm.2008.7.725.
Testo completo
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Dutz, Franz J., Sven Boje, Ulrich Orth, Alexander W. Koch e Johannes Roths. "High-Temperature Profile Monitoring in Gas Turbine Exhaust-Gas Diffusors with Six-Point Fiber-Optic Sensor Array". International Journal of Turbomachinery, Propulsion and Power 5, n. 4 (24 settembre 2020): 25. http://dx.doi.org/10.3390/ijtpp5040025.
Testo completoAbstract (sommario):
In this paper, the deployment of a newly developed, multipoint, fiber-optic temperature-sensor system for temperature distribution measurements in a 6 MW gas turbine is demonstrated. The optical sensor fiber was integrated in a stainless steel protection cable with a 1.6 mm outside diameter. It included six measurement points, distributed over a length of 110 mm. The sensor cable was mounted in a temperature probe and was positioned radially in the exhaust-gas diffusor of the turbine. With this temperature probe, the radial temperature profiles in the exhaust-gas diffusor were measured with high spatial and temporal resolution. During a test run of the turbine, characteristic temperature gradients were observed when the machine operated at different loads.
10
Neff, Helmut, Elmar Uwe Kurt Melcher, Joseana Macêdo Fechine Régis de Araújo, Sergio de Brito Espinola, Adalberto Gomes Teixeira Júnior, Samir Trajano Feitosa, Gustavo de Brito Espinola e Sergio Vinícius da Costa Cândido. "Remote Gas Emission Flux Sensing in a Thermal Power Plant Using Shadow Image Processing". Applied Mechanics and Materials 522-524 (febbraio 2014): 638–42. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.638.
Testo completoAbstract (sommario):
Total flue gas emission is a crucial quantity for control of environmental impact in thermal power plants. Direct gas flow measurements by Pitot tubes and other sensors are hampered by the very high temperature at the exhaust, high content of carbon soot and frequently turbulent flow conditions, which cause a non-parabolic flow profile across the exhaust cross section. We are developing an optical imaging method for gas flux measurements, using shadow video imaging of the dynamic hot gas emission profile at the power plant exhaust. All, high exhaust gas temperature, pressure increase and carbon soot content cause small variations of the refractive index. This deflects a considerable amount direct sunlight under inclined solar illumination conditions (at approx 38 deg inclination angle), and results in a rather sharp contrast and clear shadow image of the gas flow above the exhaust. This feature is not observable in direct transmission imaging. The distant flow shadow image pattern, as seen on the plant floor, is video monitored over a short time period and the dynamic image evolution digitally processed and analyzed. The presented method is similar to the well known optical so-called Schlieren imaging technique. Initial video processing algorithms and results are presented that provide the flue gas flow velocity directly at the exhaust exit, being close to the expected values, obtained from power plant process parameters.
11
Korczewski, Zbigniew. "Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines: Part II Unsteady processes". Polish Maritime Research 18, n. 3 (1 gennaio 2011): 37–42. http://dx.doi.org/10.2478/v10012-011-0015-x.
Testo completoAbstract (sommario):
Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines: Part II Unsteady processes The second part of the article presents the results of operating diagnostic tests of a two- and three-shaft engine with a separate power turbine during the start-up and acceleration of the rotor units. Attention was paid to key importance of the correctness of operation of the automatic engine load control system, the input for which, among other signals, is the rate of increase of the exhaust gas flow temperature. The article presents sample damages of the engine flow section which resulted from disturbed functioning of this system. The unsteady operation of the compressor during engine acceleration was the source of excessive increase of the exhaust gas temperature behind the combustion chamber and partial burning of the turbine blade tips.
12
Bakken, L. E., e L. Skogly. "Parametric Modeling of Exhaust Gas Emission From Natural Gas Fired Gas Turbines". Journal of Engineering for Gas Turbines and Power 118, n. 3 (1 luglio 1996): 553–60. http://dx.doi.org/10.1115/1.2816683.
Testo completoAbstract (sommario):
Increased focus on air pollution from gas turbines in the Norwegian sector of the North Sea has resulted in taxes on CO2. Statements made by the Norwegian authorities imply regulations and/or taxes on NOx emissions in the near future. The existing CO2 tax of NOK 0.82/Sm3 (US Dollars 0.12/Sm3) and possible future tax on NOx are analyzed mainly with respect to operating and maintenance costs for the gas turbine. Depending on actual tax levels, the machine should be operated on full load/optimum thermal efficiency or part load to reduce specific exhaust emissions. Based on field measurements, exhaust emissions (CO2, CO, NOx, N20, UHC, etc.) are established with respect to load and gas turbine performance, including performance degradation. Different NOx emission correlations are analyzed based on test results, and a proposed prediction model presented. The impact of machinery performance degradation on emission levels is particularly analyzed. Good agreement is achieved between measured and predicted NOx emissions from the proposed correlation. To achieve continuous exhaust emission control, the proposed NOx model is implemented to the on-line condition monitoring system on the Sleipner A platform, rather than introducing sensitive emission sensors in the exhaust gas stack. The on-line condition monitoring system forms an important tool in detecting machinery condition/degradation and air pollution, and achieving optimum energy conservation.
13
Jatana, Gurneesh, Lyle Kocher, Suk-Min Moon, Sriram Popuri, Kevin Augustin, Feng Tao, Yifeng Wu et al. "Mapping of exhaust gas recirculation and combustion-residual backflow in the intake ports of a heavy-duty diesel engine using a multiplexed multi-species absorption spectroscopy sensor". International Journal of Engine Research 19, n. 5 (31 luglio 2017): 542–52. http://dx.doi.org/10.1177/1468087417720588.
Testo completoAbstract (sommario):
The combustion-residual backflow into the intake ports of a commercial diesel engine (Cummins ISX series) was spatiotemporally mapped using a multiplexed multi-species absorption spectroscopy sensor system; the resulting cycle- and cylinder-resolved measurements are applicable for assessing cylinder charge uniformity, control strategies, and computational fluid dynamics tools. On-engine measurements were made using four compact (3/8 in Outside Diameter) stainless steel probes which enabled simultaneous multi-point measurements, required minimal engine hardware modification, and featured a novel tip design for measurement of gas flows parallel to the probe axis. Three sensor probes were used to perform simultaneous backflow measurements in intake runners corresponding to three of the six engine cylinders, and a fourth probe was installed in the intake manifold plenum for tracking dynamics introduced by an external exhaust gas recirculation mixer. Near-crank-angle resolved measurements (5 kHz, that is, 1.2 crank angle resolution at 1000 RPM) were performed during steady-state engine operation at various levels of external exhaust gas recirculation to measure the gas properties and penetration distance of the backflow into the intake runners on a cylinder- and cycle-basis. Validation of computational fluid dynamics model results is also presented to demonstrate the utility of such measurements in advancing engine research.
14
Otero, Raul, K. Todd Lowe, Wing F. Ng, Lin Ma e Chu-Young Kim. "Nonintrusive Gas-Turbine Engine-Exhaust Characterization Using Acoustic Measurements". Journal of Propulsion and Power 34, n. 3 (maggio 2018): 730–38. http://dx.doi.org/10.2514/1.b36579.
Testo completo
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Gis, Wojciech, e Sławomir Taubert. "The Issues of the Air-Fuel Ratio in Exhaust Emissions Tests Carried out on a Chassis Dynamometer". Energies 14, n. 9 (21 aprile 2021): 2360. http://dx.doi.org/10.3390/en14092360.
Testo completoAbstract (sommario):
Vehicle exhaust emission tests use exhaust sampling systems that dilute the exhaust gas with ambient air. The dilution factor DF is calculated assuming that the combustion is complete, and that the engine is operated at a stoichiometric air-fuel ratio (AFR). These assumptions are not always met. This is especially true for diesel engines. This article discusses the tests to find out what the average lambda (λ) over the ARTEMIS, WLTC and NEDC driving cycles is and how this affects the result of the emission measurements. Measurements were carried out on a chassis dynamometer equipped with a standard emission measurement system used during the homologation. The λ was calculated using the Brettschneider equation. The dilution ratio DR was also determined by measuring the CO2 concentration in the raw exhaust gas. The CO2-tracer method used for this was modified. The median of the λ for a CI vehicle was 1.23–3.31, which makes the relative percentage difference between the DF and DR (ΔDF) in the range of 28–167%. For a SI vehicle homologated under the WLTP procedure, the median of the λ for the WLTC and ARTEMIS cycles was close to one and ΔDF for most cycles does not exceed 10%. In order to reduce the influence of the error of DF determination on the result of the emission measurement, it is recommended to use exhaust gas sampling systems that allow to determine the actual dilution ratio or to use the lowest possible dilution. The PAS-CVS system seems to be the most promising.
16
Payri, F., E. Reyes e J. Galindo. "Analysis and Modeling of the Fluid-Dynamic Effects in Branched Exhaust Junctions of ICE". Journal of Engineering for Gas Turbines and Power 123, n. 1 (3 novembre 2000): 197–203. http://dx.doi.org/10.1115/1.1339988.
Testo completoAbstract (sommario):
The influence of exhaust junction geometry on flow-dynamics of exhaust gas is analyzed. The authors propose an experimental characterization method based on the measurement of the instantaneous pressure in the junction operating with engine exhaust flow and solving the problems posed for the accurate instantaneous pressure measurements under the adverse temperature condition. In this paper, the method is applied to two “Y” type junctions, with a reed being the unique difference between them, to determine the influence of this element on the junction behavior. The analysis of the experimental results denotes two major differences: the characteristics of the wave reflected at the junction, and the energy of the pulse transmitted to the lateral branch of the junction. The results of the analysis are introduced in the junction modeling used in a one-dimensional gas dynamic model with an important improvement in the agreement of the modeled predictions with the experimental measurements.
17
Ye, Xiangyang, Francesco Pisu, Stephan Grob, Mahesh Dhotre e Javier Mantilla. "Experiment and CFD simulation of exhaust tube in highvoltage circuit breaker". MATEC Web of Conferences 169 (2018): 01001. http://dx.doi.org/10.1051/matecconf/201816901001.
Testo completoAbstract (sommario):
In a high-voltage circuit breaker, the exhaust tube connects the arc zone with the exhaust volume. During the arc interruption process, the exhaust tube transports the hot gas from the arc interruption zone to the exhaust volume through its distributed holes. The design of a high performance exhaust tube in the circuit breaker development aims for well controlled hot gas evacuation mass flow and pressure waves. In this paper, the exhaust tube behaviour is investigated using Computational Fluid Dynamics (CFD). To verify the CFD simulation, a basic experimental study with pressure measurements at different positions of the exhaust tube is performed. Further, the design parameters influencing the exhaust tube behaviour and circuit breaker performance are investigated and discussed.
18
Kowalski, Jerzy. "The Emission and Combustion Characteristics of Marine Diesel Engine with Extreme Throttled of Air or Exhaust Ducts". New Trends in Production Engineering 1, n. 1 (1 ottobre 2018): 427–33. http://dx.doi.org/10.2478/ntpe-2018-0053.
Testo completoAbstract (sommario):
Abstract Presented paper shows the results of the laboratory tests on the relationship between the extreme throttling of both air intake duct and exhaust gas duct and gaseous emission from the marine engine. The object of research is a laboratory, 4-stroke, DI diesel engine, operated at loads from 50 kW to 250 kW at a constant speed equal to 750 rpm. During the laboratory tests the thermodynamic and exhaust gas emission characteristics of the engine were measured with technical condition recognized as “working properly” and with simulated throttling of both air intake duct and exhaust gas duct. Air intake duct throttling by 60% causes visible changes at both gas temperature and pressure behind the intercooler. The study results show significant changes of NOx and CO2 emission for considered air intake duct throttling. The best indicator of exhaust gas duct throttling among considered thermodynamic parameters of the engine is mean in-cylinder pressure. In the case of measuring the composition of exhaust gas, the throttling of the exhaust gas duct causes visible changes in CO2 and NOx emission. The conclusion is that the results of measurements of the composition of the exhaust gas may contain valuable diagnostic information about the technical condition of air intake and exhaust gas duct of the marine engine.
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Giechaskiel, Barouch, Alessandro A. Zardini e Michael Clairotte. "Exhaust Gas Condensation during Engine Cold Start and Application of the Dry-Wet Correction Factor". Applied Sciences 9, n. 11 (31 maggio 2019): 2263. http://dx.doi.org/10.3390/app9112263.
Testo completoAbstract (sommario):
Gas components, like carbon monoxide (CO) and dioxide (CO2), can be measured on a wet- or dry-basis depending on whether the water is left or removed from the sample before analysis. The dry concentrations of gaseous components in the exhaust from internal combustion engines are converted to wet concentrations with conversion factors based on the combustion products and the fuel properties. Recent CO2 measurements with portable emissions measurement systems (PEMS) compared to laboratory grade equipment showed differences during the first minutes after engine start. In this study we compared instruments measuring on a dry- and wet-basis using different measuring principles (non-dispersive infrared detection (NDIR) and Fourier-transform infrared spectroscopy (FTIR)) at the exhaust of gasoline, compressed natural gas (CNG), and diesel light-duty and L-category vehicles. The results showed an underestimation of the CO2 and CO mass emissions up to 13% at cold start when the conversion factor is applied and not direct “wet” measurements are taken, raising concerns about reported CO2 and CO cold start emissions in some cases. The underestimation was negligible (<1%) for CO2 when the whole test (20–30 min) was considered, but not for CO (1%–10% underestimation) because the majority of emissions takes place at cold start. Exhaust gas temperature, H2O measurements and different expressions of the dry-wet corrections confirmed that the differences are due to condensation at the exhaust pipes and aftertreatment devices when the surface temperatures are lower than the dew point of the exhaust gases. The results of this study help to interpret differences when comparing instruments with different principles of operation at the same location, instruments sampling at different locations, or the same instrument measuring different driving test cycles or at different ambient temperatures (e.g., −7 °C).
20
DUTCZAK, Jerzy. "PM emission in the exhaust gas of SI engines fed with petrol or LPG". Combustion Engines 158, n. 3 (1 luglio 2014): 36–44. http://dx.doi.org/10.19206/ce-116935.
Testo completoAbstract (sommario):
The paper presents measurements of PM emission in the exhaust gas of a gasoline fueled SI engine alternatively fueled with LPG. The research was performed on a 170.A1 engine using the Dekati ELPI+ PM analyzer and Micro Diluter 6100 (a micro-dilution tunnel). The author also measured the concentration of exhaust gaseous components with the use of Horiba MEXA 1500GH analyzer. The author compared the PM concentration and size distribution in the exhaust gas for both fuels.
21
Llamas, Xavier, e Lars Eriksson. "Control-oriented modeling of two-stroke diesel engines with exhaust gas recirculation for marine applications". Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, n. 2 (11 maggio 2018): 551–74. http://dx.doi.org/10.1177/1475090218768992.
Testo completoAbstract (sommario):
Large marine two-stroke diesel engines are widely used as propulsion systems for shipping worldwide and are facing stricter NO x emission limits. Exhaust gas recirculation is introduced to these engines to reduce the produced combustion NO x to the allowed levels. Since the current number of engines built with exhaust gas recirculation is low and engine testing is very expensive, a powerful alternative for developing exhaust gas recirculation controllers for such engines is to use control-oriented simulation models. Unfortunately, the same reasons that motivate the use of simulation models also hinder the capacity to obtain sufficient measurement data at different operating points for developing the models. A mean value engine model of a large two-stroke diesel with exhaust gas recirculation that can be simulated faster than real time is presented and validated. An analytic model for the cylinder pressure that captures the effects of changes in the fuel control inputs is also developed and validated with cylinder pressure measurements. A parameterization procedure that deals with the low number of measurement data available is proposed. After the parameterization, the model is shown to capture the stationary operation of the real engine well. The transient prediction capability of the model is also considered satisfactory which is important if the model is to be used for exhaust gas recirculation controller development during transients. Furthermore, the experience gathered while developing the model about essential signals to be measured is summarized, which can be very helpful for future applications of the model. Finally, models for the ship propeller and resistance are also investigated, showing good agreement with the measured ship sailing signals during maneuvers. These models give a complete vessel model and make it possible to simulate various maneuvering scenarios, giving different loading profiles that can be used to investigate the performance of exhaust gas recirculation and other controllers during transients.
22
Ganguli, R. "Application of Fuzzy Logic for Fault Isolation of Jet Engines". Journal of Engineering for Gas Turbines and Power 125, n. 3 (1 luglio 2003): 617–23. http://dx.doi.org/10.1115/1.1470481.
Testo completoAbstract (sommario):
A fuzzy logic system is developed for gas turbine module fault isolation. Inputs to the fuzzy logic system are measurement deviations of gas path parameters from a “good” baseline engine. The gas path measurements used are exhaust gas temperature, low and high rotor speed, and fuel flow. These sensor measurements are available on most jet engines. The fuzzy logic system uses rules developed from performance influence coefficients to isolate the module fault while accounting for uncertainty in the gas path measurements. Tests with simulated data show the fuzzy system isolates module faults with accuracy of over 95%. In addition, the fuzzy logic system shows good performance even with poor quality data. Additional pressure and temperature measurements between the compressor and before the burner help to increase the accuracy of fault isolation at high levels of uncertainty and when modeling assumptions weaken.
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Myers, J., M. Myers e P. Myers. "On the Computation of Emissions From Exhaust Gas Composition Measurements". Journal of Engineering for Gas Turbines and Power 111, n. 3 (1 luglio 1989): 410–23. http://dx.doi.org/10.1115/1.3240270.
Testo completoAbstract (sommario):
This paper presents a calculation technique and related computer program to yield mass emission rates from measured exhaust gas composition and fuel flow rate or fuel plus air flow rate (if air flow rate is measured). The sensitivity of the computed emission rates to (1) the method of calculation and (2) experimental measurement errors is investigated. It is recommended that published emission rates be the average of the rates computed by several different methods, as discussed in this paper, to minimize the effect of experimental variations in measurement. This, plus use of the computer program presented, would standardize the assumptions used in computing emissions and minimize differences in reported emission rates from different laboratories.
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Gaze, Błażej, Bernard Knutel, Krzysztof Zając, Mateusz Jajczyk e Przemysław Bukowski. "Comparison of Selected Technologies to Improve the Quality of Exhaust Gases from Landfill Gas Combustion". Energies 15, n. 3 (21 gennaio 2022): 778. http://dx.doi.org/10.3390/en15030778.
Testo completoAbstract (sommario):
This paper presents the results of research on exhaust gases from landfill gas combustion. The measurements were carried out in a reclaimed landfill in Kiełcz (a passive degassing system based on gas flare). The research concerned the effects of selected exhaust gas purification technologies (platinum catalyzer on a ceramic carrier, molecular sieve, copper(II) oxide) for the quality of exhaust gases, and their particulate matter content. This paper aims to indicate which catalytic systems are most suitable for this gas type and their most efficient positioning in the flue gas duct. Due to increasingly stringent emission standards, the outcomes presented in this article could be helpful for landfill owners who wish to avoid paying fines for not complying with applicable limits. The measurements were carried out using a flue gas analyser, a particulate matter analyser fitted with a probe, and four thermocouples connected with the data recorder. The research outcomes determined the percentage reduction of pollutant emissions into the atmosphere (CO, NOx, and particulate matter) using catalysts. The potential benefits of using catalysts in landfill gas combustion systems due to their operating temperature ranges are discussed.
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Puzinauskas, Paulius V., Daniel B. Olsen e Bryan D. Willson. "Cycle-Resolved NO Measurements in a Two-Stroke Large-Bore Natural Gas Engine". Journal of Engineering for Gas Turbines and Power 126, n. 2 (1 aprile 2004): 429–41. http://dx.doi.org/10.1115/1.1635401.
Testo completoAbstract (sommario):
Cycle-resolved NO data were acquired from a Cooper-Bessemer GMV 4TF two-stroke engine to better understand and quantify large bore natural gas engine NOx emission. The cycle resolved NO data were extracted separately from the engine’s cylinder two and four exhaust ports and taken simultaneously with cycle resolved pressure traces, conventional steady-state emission measurements and a variety of additional performance and diagnostic data. The test variables were intake manifold boost pressure, ignition method and ignition timing. Relationships between individual cycle pressure traces and the NO produced by that cycle were investigated. Furthermore, mass-averaged NO values were calculated and integrated in order to compare with average exhaust emissions from a steady-state analyzer and combustion pressure characteristics. The steady measurements revealed that NO and NO2 emissions respond differently to the test variables. The mass averaged cycle-resolved NO values compare well with the steady exhaust emission measurements and exhibit strong correlations with peak pressure and crank angle location of peak pressure.
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Huang, C., H. L. Wang, L. Li, Q. Wang, Q. Lu, J. A. de Gouw, M. Zhou, S. A. Jing, J. Lu e C. H. Chen. "VOC species and emission inventory from vehicles and their SOA formation potentials estimation in Shanghai, China". Atmospheric Chemistry and Physics Discussions 15, n. 6 (17 marzo 2015): 7977–8015. http://dx.doi.org/10.5194/acpd-15-7977-2015.
Testo completoAbstract (sommario):
Abstract. VOC species from vehicle exhaust and gas evaporation were investigated by chassis dynamometer and on-road measurements of 9 gasoline vehicles, 7 diesel vehicles, 5 motorcycles, and 4 gas evaporation samples. The SOA mass yields of gasoline, diesel, motorcycle exhausts, and gas evaporation were calculated based on the mixing ratio of individual VOC species. The SOA mass yields of gasoline and motorcycle exhaust were similar to the results of the published smog chamber study with the exception of that of diesel exhaust was 20% lower than experimental data (Gordon et al., 2013, 2014a, b). This suggests the requirement for further research on SVOC or LVOC emissions. A vehicular emission inventory was compiled based on a local survey of vehicle mileage traveled and real-world measurements of vehicle emission factors. The inventory-based vehicular initial emission ratio of OA to CO was 15.6 μg m−3 ppmv−1. The OA production rate reached 22.3 and 42.7 μg m−3 ppmv−1 under high-NOx and low-NOx conditions, respectively. To determine the vehicular contribution to OA pollution, the inventory-based OA formation ratios for vehicles were calculated with a photochemical-age-based parameterization method and compared with the observation-based OA formation ratios in the urban atmosphere of Shanghai. The results indicated that VOC emissions from vehicle exhaust and gas evaporation only explained 15 and 22% of the total organic aerosols observed in summer and winter, respectively. SOA production only accounted for 25 and 18% of the total vehicular OA formation in summer and winter. VOC emissions from gasoline vehicles contribute 21–38% of vehicular OA formation after 6–24 h of photochemical aging. The results suggest that vehicle emissions are an important contributor to OA pollution in the urban atmosphere of Shanghai. However, a large number of OA mass in the atmosphere still cannot be explained in this study. SOA formation contributions from other sources (e.g. coal burning, biomass burning, cooking, dust, etc.) as well as IVOCs and SVOCs from the combustion sources need to be considered in future studies.
27
Xia, Hua, Doug Byrd, Sachin Dekate e Boon Lee. "High-Density Fiber Optical Sensor and Instrumentation for Gas Turbine Operation Condition Monitoring". Journal of Sensors 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/206738.
Testo completoAbstract (sommario):
Gas turbine operation control is normally based on thermocouple-measured exhaust temperatures. Due to radiation shielding and bulky package, it is difficult to provide high spatial resolution for measuring can-to-can combustion temperature profile at the exhaust duct. This paper has demonstrated that wavelength-division-multiplexing-based fiber Bragg grating sensors could provide high spatial resolution steady and dynamic temperature measurements. A robust sensor package can be designed with either circumferential sensing cable or radial sensing rake for quasi-distributing multiple fiber sensors in the gas turbine environment. The field validations have demonstrated that quasi-distributed fiber sensors have not only demonstrated its temperature measurement accuracy compared to existing thermocouple sensors but also shown its unique dynamic response amplitude and power spectra that could be utilized for gas turbine transient operation condition monitoring and diagnostics.
28
Hellinga, C., P. Vanrolleghem, M. C. M. van Loosdrecht e J. J. Heijnen. "The potential of off-gas analyses for monitoring wastewater treatment plants". Water Science and Technology 33, n. 1 (1 gennaio 1996): 13–23. http://dx.doi.org/10.2166/wst.1996.0002.
Testo completoAbstract (sommario):
Continuous CO2 and O2 measurements in the exhaust gas of wastewater treatment plants have been simulated to study their significance for fast process monitoring. More specifically, the question was raised whether the ratio of the carbon dioxide production rate to the oxygen consumption rate (the RQ value) can be used to distinguish C-oxidation from N-removal (nitrification or combined nitrification-denitrification). Although the oxygen uptake rate and carbon dioxide production rate by the micro-organisms are indicative indeed, these rates can not very well be monitored in the gas phase mainly due to the additional CO2 production accompanying alkalinity consumption. Only large changes in nitrification activity can be monitored this way. The RQ is however a strong measure for the COD/TOC ratio of the converted waste. Combination of RQ measurements with TOC measurements can therefore probably replace laborious COD measurements. In plants with combined C-removal and nitrification, the difference in in- and effluent alkalinity is a measure for nitrification. If NH3-removal is determined, the biomass production rate can be calculated from the gas flow rate in combination with the exhaust CO2 and O2 measurements.
29
Jatana, Gurneesh S., e Brian C. Kaul. "Characterization of temporal variations and feedback timescales of exhaust gas recirculation gas properties using high-speed diode laser absorption spectroscopy for next-cycle control of cyclic variability". International Journal of Engine Research 20, n. 8-9 (11 ottobre 2018): 945–52. http://dx.doi.org/10.1177/1468087418805654.
Testo completoAbstract (sommario):
Dilute combustion offers efficiency gains in boosted gasoline direct injection engines both through knock-limit extension and thermodynamic advantages (i.e. the effect of γ on cycle efficiency), but is limited by cyclic variability at high dilution levels. Past studies have shown that the cycle-to-cycle dynamics are a combination of deterministic and stochastic effects. The deterministic causes of cyclic variations, which arise from feedback due to exhaust gas recirculation, imply the possibility of using active control strategies for dilution limit extension. While internal exhaust gas recirculation will largely provide a next-cycle effect (short-timescale feedback), the feedback of external exhaust gas recirculation will have an effect after a delay of several cycles (long timescale). Therefore, control strategies aiming to improve engine stability at dilution limit may have to account for both short- and long-timescale feedback pathways. This study shows the results of a study examining the extent to which variations in exhaust gas recirculation composition are preserved along the exhaust gas recirculation flow path and thus the relative importance and information content of the long-timescale feedback pathway. To characterize the filtering or retention of cycle-resolved feedback information, high-speed (1–5 kHz) CO2 concentration measurements were performed simultaneously at three different locations along the low-pressure external exhaust gas recirculation loop of a four-cylinder General Motors gasoline direct injection engine using a multiplexed two-color diode laser absorption spectroscopy sensor system during steady-state and transient engine operation at various exhaust gas recirculation levels. It was determined that cycle-resolved feedback propagates through internal residual gases but is filtered out by the low-pressure exhaust gas recirculation flow system and do not reach the intake manifold. Intermediate variations driven by flow rate and compositional changes are also distinguished and identified.
30
Zhou, Fan, Shengda Pan, Wei Chen, Xunpeng Ni e Bowen An. "Monitoring of compliance with fuel sulfur content regulations through unmanned aerial vehicle (UAV) measurements of ship emissions". Atmospheric Measurement Techniques 12, n. 11 (25 novembre 2019): 6113–24. http://dx.doi.org/10.5194/amt-12-6113-2019.
Testo completoAbstract (sommario):
Abstract. Air pollution from ship exhaust gas can be reduced by the establishment of emission control areas (ECAs). Efficient supervision of ship emissions is currently a major concern of maritime authorities. In this study, a measurement system for exhaust gas from ships based on an unmanned aerial vehicle (UAV) was designed and developed. Sensors were mounted on the UAV to measure the concentrations of SO2 and CO2 in order to calculate the fuel sulfur content (FSC) of ships. The Waigaoqiao port in the Yangtze River Delta, an ECA in China, was selected for monitoring compliance with FSC regulations. Unlike in situ or airborne measurements, the proposed measurement system could be used to determine the smoke plume at about 5 m from the funnel mouth of ships, thus providing a means for estimating the FSC of ships. In order to verify the accuracy of these measurements, fuel samples were collected at the same time and sent to the laboratory for chemical examination, and these two types of measurements were compared. After 23 comparative experiments, the results showed that, in general, the deviation of the estimated value for FSC was less than 0.03 % (m/m) at an FSC level ranging from 0.035 % (m/m) to 0.24 % (m/m). Hence, UAV measurements can be used for monitoring of ECAs for compliance with FSC regulations.
31
Zhu, Xiaorui, Shunchun Yao, Wei Ren, Zhimin Lu e Zhenghui Li. "TDLAS Monitoring of Carbon Dioxide with Temperature Compensation in Power Plant Exhausts". Applied Sciences 9, n. 3 (28 gennaio 2019): 442. http://dx.doi.org/10.3390/app9030442.
Testo completoAbstract (sommario):
Temperature variations of flue gas have an effect on carbon dioxide (CO2) emissions monitoring. This paper demonstrates accurate CO2 concentration measurement using tunable diode laser absorption spectroscopy (TDLAS) with temperature compensation methods. A distributed feedback diode laser at 1579 nm was chosen as the laser source for CO2 measurements. A modeled flue gas was made referring to CO2 concentrations of 10–20% and temperatures of 298–338 K in the exhaust of a power plant. Two temperature compensation methods based on direct absorption (DA) and wavelength modulation (WMS) are presented to improve the accuracy of the concentration measurement. The relative standard deviations of DA and WMS measurements of concentration were reduced from 0.84% and 0.35% to 0.42% and 0.31%, respectively. Our experimental results have validated the rationality of temperature compensations and can be further applied for high-precision measurement of gas concentrations in industrial emission monitoring.
32
Putra, Dwi Sudarno, Donny Fernandez e Gito Gito Giantoro. "Analisa Pengaruh Penggunaan Sensor Oksigen Terhadap Kandungan Emisi Gas Buang CO Dan HC". Jurnal Ilmiah Poli Rekayasa 10, n. 2 (14 aprile 2015): 36. http://dx.doi.org/10.30630/jipr.10.2.9.
Testo completoAbstract (sommario):
The use of oxygen sensors on vehicles intended to reduce the harmful content from vehicle exhaust emissions. Research and journal was prepared to find how much reduction can be achieved. Research conducted by the experimental method. This type of machine used is K3-VE engine Avanza. Measurements are performed using the exhaust emission analyzer Fourgas at some level of engine speed. From the research proven when using oxygen sensors decrease harmful content of exhaust emissions. The decline in the percentage of the CO content of 1.86% and the average number of HC ppm reduced the total 258.33ppm.
33
Bajerlein, Maciej, Wojciech Karpiuk e Rafał Smolec. "Application of Gas Dissolved in Fuel in the Aspect of a Hypocycloidal Pump Design". Energies 15, n. 23 (2 dicembre 2022): 9163. http://dx.doi.org/10.3390/en15239163.
Testo completoAbstract (sommario):
The advancement of modern injection systems of diesel engines is related to a constant increase in the injection pressures generated by injection pumps. This translates into an improvement of the engine operation indexes, including the emission-related ones. Such an approach brings a series of problems related to the design, construction and durability of the injection system. Therefore, the authors asked whether the current market trend in injection systems is the only appropriate path to be taken. When searching for the answer, the authors decided to propose an innovative concept consisting of dissolving exhaust gas in diesel fuel with the use of an injection pump. Such a saturated solution, when flowing out of the injection nozzle, begins the process of releasing the gas dissolved in the fuel. This has a positive impact on the atomization process, hence the process of combustion. The aim of this paper stems from the previously performed research. Due to the nature of the phenomenon, it was necessary to propose a new design for the injection pump. For correct selection of the dimensions of the pumping section, it was of key importance to determine the coefficient of solubility and the bulk modulus of the solution of diesel fuel and exhaust gas. Aside from the description of the applied method and the results of the direct measurements, this paper presents the yet undescribed results of the measurements of the coefficient of solubility of different concentrations of exhaust gas in diesel fuel. The authors also investigated the influence of the amount of exhaust gas dissolved in the fuel on the bulk modulus of the solution. The final part of the paper is a description of a proprietary design of a hypocycloidal injection pump. The application of the innovative drive allows a correct dissolution of exhaust gas in the fuel.
34
Zhao, H., J. Hu e N. Ladommatos. "In-cylinder studies of the effects of CO2 in exhaust gas recirculation on diesel combustion and emissions". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 214, n. 4 (1 aprile 2000): 405–19. http://dx.doi.org/10.1243/0954407001527727.
Testo completoAbstract (sommario):
This paper reports the results of the effects of CO2 in exhaust gas recirculation (EGR) on diesel combustion and emissions. The experiments were carried out on a specially designed single-cylinder diesel engine. In-cylinder measurements were obtained from the optically accessible swirl chamber using high-speed shadowgraphy, the two-colour method and laser extinction. Furthermore, in-cylinder pressure measurements from the combustion chambers were used to derive the heat release rates during combustion. Two experiments were carried out on the effects of CO2 on diesel combustion and pollutant formation. In the first series of experiments, CO2 was used to replace some of the oxygen in the intake mixture, which simulated the dilution effect of conventional EGR. This so-called replacement EGR method was characterized by the typical NOx and smoke trade-off, where NOx reduction was accomplished at the expense of exhaust smoke. In the second series of tests, CO2 was added to the intake charge so that the oxygen concentration in the combustion chamber was not affected. In this additional EGR method, CO2 was found to suppress both NOx and smoke emissions. The mechanisms of these two different EGR modes on diesel combustion and emissions were examined using the above in-cylinder measurement techniques and exhaust emission analysis.
35
Macor, Alarico, e Alberto Benato. "Regulated Emissions of Biogas Engines—On Site Experimental Measurements and Damage Assessment on Human Health". Energies 13, n. 5 (26 febbraio 2020): 1044. http://dx.doi.org/10.3390/en13051044.
Testo completoAbstract (sommario):
Despite biogas renewability, it is mandatory to experimentally assess its combustion products in order to measure their pollutants content. To this purpose, the Authors selected six in-operation biogas plants fed by different substrates and perform an on-site experimental campaign for measuring both biogas and engines exhausts composition. Firstly, biogas measured compositions are compared among them and with data available in literature. Then, biogas engines’ exhaust compositions are compared among them, with data available in literature and with measurements obtained from an engine characterised by the same design power but fuelled with natural gas. Finally, the Health Impact Assessment analysis is used to estimate the damage on human health caused by both biogas and natural gas engines emissions. Results show that biogas causes a damage on human health three times higher than the natural gas one. But, this approach does not consider biogas renewability. So, to include this important aspect, also an analysis which considers Global Warming categories is carried out. Results highlight that natural gas is twice harmful than biogas.
36
KOWALSKI, Jerzy. "The model of combustion process in the marine 4-stroke engine for exhaust gas composition assessment". Combustion Engines 165, n. 2 (1 maggio 2016): 60–69. http://dx.doi.org/10.19206/ce-2016-208.
Testo completoAbstract (sommario):
The paper presents the model of combustion process in the marine, turbocharged, 4-stroke and Diesel engine. The main target of modeling is the assessment of the exhaust gas composition. Presented multi-zone, 3-D model of combustion process consists of the following sub-models of processes: the fuel injection, the brake-up and the evaporation of fuel and the turbulence flow and the heat transfer phenomena. Presented model basis on the 3Z-ECFM mechanism of combustion and the initial and boundary conditions collected during direct measurements. The positive validation of the calculation results are obtained for mean and maximum value of the combustion pressure and values of oxygen and nitric oxides fractions in the exhaust gas. Unfortunately, fractions of carbon compounds in the exhaust gas are not properly calculated.
37
Sultanian, B. K., S. Nagao e T. Sakamoto. "Experimental and Three-Dimensional CFD Investigation in a Gas Turbine Exhaust System". Journal of Engineering for Gas Turbines and Power 121, n. 2 (1 aprile 1999): 364–74. http://dx.doi.org/10.1115/1.2817129.
Testo completoAbstract (sommario):
Both experimental and three-dimensional CFD investigations are carried out in a scale model of an industrial gas turbine exhaust system to better understand its complex flow field and to validate CFD prediction capabilities for improved design applications. The model consists of an annular diffuser passage with struts, followed by turning vanes and a rectangular plenum with side exhaust. Precise measurements of total/static pressure and flow velocity distributions at the model inlet, strut outlet and model outlet are made using aerodynamic probes and locally a Laser Doppler Velocimeter (LDV). Numerical analyses of the model internal flow field are performed utilizing a three-dimensional Navier-Stokes (N-S) calculation method with the industry standard k-ε turbulence model. Both the experiments and computations are carried out for three load conditions: full speed no load (FSNL), full speed mid load (FSML, 57 percent load), and full speed full load (FSFL). Based on the overall comparison between the measurements and CFD predictions, this study concludes that the applied N-S method is capable of predicting complicated gas turbine exhaust system flows for design applications.
38
NYERGES, Ádám, e Máté ZÖLDY. "Model development and experimental validation of an exhaust brake supported dual loop exhaust gas recirculation on a medium duty Diesel engine". Mechanics 26, n. 6 (7 dicembre 2020): 486–96. http://dx.doi.org/10.5755/j01.mech.26.6.25017.
Testo completoAbstract (sommario):
Due to the new European emission norms internal combustion engines have to comply stricter rules. The new norms contain new requirements that were not included in previous regulations for example the decreased temperature of the cold start or the real driving emission part. The emission cycles for passenger vehicles are completely news, the stricter emission norms for commercial vehicles will follow them within a few years. Despite the increasing spread of alternative transmission systems in road transport Diesel engines are going to be remain in commercial vehicles in the next decades due to their good torque and fuel consumption performance. The emission of Diesel engines can be kept low by several way: by the modification of combustion processes, or by exhaust gas after treatment. To comply future regulations both of them seems to be necessary. By exhaust gas recirculation systems alternative Diesel combustion processes can be realized which can provide lower nitrogen-oxide emission and in several operation points also lower fuel consumption. Exhaust gas recirculation systems also can support the thermal management of a Diesel engine. To utilize the advantages of the recirculated exhaust gases a complex system is necessary to get a freedom in control possibilities: duel loop exhaust gas recirculated systems supplemented with supporter valves on the intake or on the exhaust side. In this paper a pressure and mass flow rate based control oriented engine model will be presented which contains high and low pressure exhaust gas recirculation systems and both of them are supported by exhaust brakes. The model considers four balance volumes and it has five state variables. The model is validated by an engine dyno measurements on a medium duty Diesel engine.
39
Kowalski, Jerzy. "An Experimental Study of Emission and Combustion Characteristics of Marine Diesel Engine in Case of Cylinder Valves Leakage". Polish Maritime Research 22, n. 3 (1 settembre 2015): 90–98. http://dx.doi.org/10.1515/pomr-2015-0061.
Testo completoAbstract (sommario):
Abstract Presented paper shows the results of the laboratory tests on the relationship between throttling of both air intake duct and exhaust gas duct and a gaseous emission from the marine engine. The object of research is a laboratory, four-stroke, DI diesel engine, operated at loads from 50 kW to 250 kW at a constant speed equal to 750 rpm. During the laboratory tests over 50 parameters of the engine were measured with its technical condition recognized as a „working properly” and with simulated leakage of both air intake valve and exhaust gas valve on the second cylinder. The results of this laboratory research confirm that the leakage of cylinder valves causes no significant changes of the thermodynamic parameters of the engine. Simulated leakages through the inlet and exhaust valve caused a significant increase in fuel consumption of the engine. Valve leakages cause an increase of the exhaust gas temperature behind the cylinder with leakage and behind other cylinders. The exhaust gas temperature increase is relatively small and clearly visible only at low loads of the engine. The increase of the temperature and pressure of the charging air behind the intercooler were observed too. Charging air temperature is significantly higher during the engine operation with inlet valve leakage. The study results show significant increases of the CO, NOx and CO2 emission for all the mentioned malfunctions. The conclusion is that the results of measurements of the composition of the exhaust gas may contain valuable diagnostic information about the technical condition of the air intake duct and the exhaust gas duct of the marine engine.
40
PUZDROWSKA, Patrycja. "Application of the F-statistic of the Fisher-Snedecor distribution to analyze the significance of the effect of changes in the compression ratio of a diesel engine on the value of the specific enthalpy of the exhaust gas flow". Combustion Engines 186, n. 3 (13 settembre 2021): 80–88. http://dx.doi.org/10.19206/ce-141346.
Testo completoAbstract (sommario):
The paper discusses the impact of changes in the compression ratio on the operating parameters of a diesel engine, e.g. on the temperature of exhaust gases. It presents the construction of the laboratory test stand, on which experimental measurements were realized. It is characterized how the actual changes of the compression ratio were introduced to the existing engine. The program of experimental investigations taking into account the available test stand and measurement possibilities was described. A statistical and qualitative analysis of the obtained measurement results was made. The use of F statistics of the Fisher-Snedecor distribution was proposed to assess the significance of the effect of compression ratio changes on the specific enthalpy of the exhaust gas stream. The specific enthalpy of exhaust gases was analysed for one cycle of diesel engine work, determined on the basis of the course of quickly varying temperature of exhaust gases. The results of these analyses are discussed and the utilitarian purpose of this type of evaluation in parametric diagnostics of piston engines is presented.
41
Maldonado, Bryan P., Nan Li, Ilya Kolmanovsky e Anna G. Stefanopoulou. "Learning reference governor for cycle-to-cycle combustion control with misfire avoidance in spark-ignition engines at high exhaust gas recirculation–diluted conditions". International Journal of Engine Research 21, n. 10 (26 giugno 2020): 1819–34. http://dx.doi.org/10.1177/1468087420929109.
Testo completoAbstract (sommario):
Cycle-to-cycle feedback control is employed to achieve optimal combustion phasing while maintaining high levels of exhaust gas recirculation by adjusting the spark advance and the exhaust gas recirculation valve position. The control development is based on a control-oriented model that captures the effects of throttle position, exhaust gas recirculation valve position, and spark timing on the combustion phasing. Under the assumption that in-cylinder pressure information is available, an adaptive extended Kalman filter approach is used to estimate the exhaust gas recirculation rate into the intake manifold based on combustion phasing measurements. The estimation algorithm is adaptive since the cycle-to-cycle combustion variability (output covariance) is not known a priori and changes with operating conditions. A linear quadratic regulator controller is designed to maintain optimal combustion phasing while maximizing exhaust gas recirculation levels during load transients coming from throttle tip-in and tip-out commands from the driver. During throttle tip-outs, however, a combination of a high exhaust gas recirculation rate and an overly advanced spark, product of the dynamic response of the system, generates a sequence of misfire events. In this work, an explicit reference governor is used as an add-on scheme to the closed-loop system in order to avoid the violation of the misfire limit. The reference governor is enhanced with model-free learning which enables it to avoid misfires after a learning phase. Experimental results are reported which illustrate the potential of the proposed control strategy for achieving an optimal combustion process during highly diluted conditions for improving fuel efficiency.
42
MERKISZ, Jerzy, Maciej BAJERLEIN e Bartłomiej ZIELIŃSKI. "The impact of parameter modifications in the Diesel engine power system on the emissions of harmful compounds". Combustion Engines 180, n. 1 (30 marzo 2020): 36–40. http://dx.doi.org/10.19206/ce-2020-106.
Testo completoAbstract (sommario):
The article presents the results of emission tests and vehicle operation indicators fueled with diesel oil. The tests were carried out for a passenger vehicle equipped with a diesel engine meeting Euro 3 emissions standard, moving in urban traffic. The measurements were carried out using modern PEMS (Portable Emission Measurement System) enabling the emission of gaseous components from exhaust systems of the tested object. On the basis of the conducted tests, the load characteristics were determined using the torque values obtained along with the engine speeds. The measurement route included two cycles: urban driving and fast acceleration. The aim of the study was to assess the impact of modifications to the control maps on CO, CO2, PM and NOx exhaust gas emissions under real operating conditions.
43
Książek, Ireneusz, Andrzej Brosławski, Henryk Janus e Ewa Pawelec. "Applicability of the dielectric barrier discharge for helium ash measurements in the divertor region". Nukleonika 61, n. 2 (1 giugno 2016): 99–102. http://dx.doi.org/10.1515/nuka-2016-0017.
Testo completoAbstract (sommario):
Abstract Controlled fusion based on the magnetic confinement of the plasma is one of the main aims of the Euro-fusion programme. In the fusion device, the hydrogen isotopes, in nuclear reactions, will produce helium nuclei. The products, as the ash, will be removed from the plasma in the region of the so-called divertor. Controlling the helium to hydrogen ratio in this ‘exhaust gas’ will provide information about the efficiency of the fusion process as well as of the efficiency of the helium removal system. One of the methods to perform this task is to study the properties of the discharge conducted in such exhaust gas. In this paper, the applicability of the dielectric barrier discharge (DBD) is studied. This preliminary experiment shows a great potential in applicability of this kind of discharge. The optical as well as pulse-height spectra were studied, both revealing very promising properties. In the optical spectrum, one can observe well separated hydrogen and helium spectral lines, with intensities of the same order of magnitude. Moreover, in the registered spectral region, the molecular spectra are negligible. The pulse-height spectra reveal very distinct shape in helium and hydrogen. Checking of this spectrum could provide parallel (redundant) information about the partial pressure of helium in the magnetic confinement fusion (MCF) device exhaust gas.
44
Fischer, S., D. Schönauer-Kamin, R. Pohle, M. Fleischer e R. Moos. "Influence of operation temperature variations on NO measurements in low concentrations when applying the pulsed polarization technique to thimble-type lambda probes". Journal of Sensors and Sensor Systems 4, n. 2 (23 novembre 2015): 321–29. http://dx.doi.org/10.5194/jsss-4-321-2015.
Testo completoAbstract (sommario):
Abstract. By applying the pulsed polarization technique, a thimble-type lambda probe can be used as a NOx sensor in the low ppm range. Due to the robustness of the sensor in harsh exhaust gas environments, this approach has many opportunities for application. The temperature operating range for best NO sensing properties is a crucial parameter. The sensor temperature changes with the ambient gas temperature, but can be stabilized actively by internal heating in a certain temperature range. This study evaluates in detail the temperature influence on NO sensitivity, so that an optimum operating point can be derived from these results using a dynamic measurement technique. Stepwise NO concentration changes between 0 and 12.5 ppm in synthetic exhausts demonstrate the potential of the concept.
45
George, Benny, e N. Muthuveerappan. "Error Estimation of Measured Exhaust Gas Temperature in Afterburner Mode in an Aero Gas Turbine Engine". Defence Science Journal 72, n. 1 (5 gennaio 2022): 10–17. http://dx.doi.org/10.14429/dsj.72.16824.
Testo completoAbstract (sommario):
In a turbofan engine, thrust is a key parameter which is measured or estimated from various parameters acquired during engine testing in an engine testbed. Exhaust Gas Temperature (EGT) is the most critical parameter used for thrust calculation. This work presents a novel way to measure and correct the errors in EGT measurement. A temperature probe is designed to measure EGT in the engine jet pipe using thermocouples. The temperature probe is designed to withstand the mechanical and temperature loads during the operation. Structural analysis at the design stage provided a strength margin of 90% and eigenfrequency margin of more than 20%. Thermal analysis is carried out to evaluate maximum metal temperature. Errors are quite high in high-temperature measurements which are corrected using the available methodologies. The velocity error, conduction error, and radiation error are estimated for the measured temperature. The difference of 97 K between the measured gas temperature and calculated gas temperature from measured thrust is explained. The estimated velocity error is 1 K, conduction error is 3 K, and radiation error is 69 K. Based on the error estimation, the measurement error is brought down to 24 K. After applying the above corrections, the further difference of 24 K between measured and estimated value can be attributed to thermocouple error of +/-0.4% of the reading for class 1 accuracy thermocouple, other parameter measurement errors, and analysis uncertainties. The present work enables the designer to calculate the errors in high-temperature measurement in a turbofan engine.
46
Stelmasiak, Zdzisław, Jerzy Larisch, Jacek Pielecha e Dariusz Pietras. "Particulate Matter Emission from Dual Fuel Diesel Engine Fuelled with Natural Gas". Polish Maritime Research 24, n. 2 (27 giugno 2017): 96–104. http://dx.doi.org/10.1515/pomr-2017-0055.
Testo completoAbstract (sommario):
Abstract The paper presents the results of examination of particulate matter emission from the Diesel engine FPT 1.3 MJT simultaneously fuelled with diesel oil and natural gas CNG. The basic premise for engine adaptation was the addition of a small amount of CNG to reduce exhaust gas opacity and particulate matter emission. At this assumption, diesel oil remained the basic fuel, with contribution amounting to 0,70-0,85 of total energy delivered to the engine. The dual fuel engine was examined using an original controller installed in the Diesel engine FPT 1.3 MJT which controlled the diesel fuel dose. The dose of the injected natural gas was controlled by changing the opening time of gas injectors at constant pressure in the gas collector. The examined issues included the exhaust gas opacity, and the total number and fractional distribution of the emitted particles. The measurements were performed at twenty selected measuring points corresponding to the New European Driving Cycle (NEDC) test. The performed tests have demonstrated a positive effect of gas addition on exhaust gas opacity and particulate matter emission. Depending on test conditions, the exhaust gas opacity was reduced by 10÷92%, and the total number of particles by 30÷40%. The performed tests have revealed that a small addition of gas can reduce the load of the DPF filter, extend its lifetime, and increase engine reliability. Longer time intervals between successive DPF filter regenerations improve ecological properties of the engine.
47
Siokos, Konstantinos, Rohit Koli e Robert Prucka. "Short-term and long-term adaptation algorithm for low-pressure exhaust gas recirculation estimation in spark-ignition engines". International Journal of Engine Research 20, n. 4 (4 marzo 2018): 424–40. http://dx.doi.org/10.1177/1468087418758492.
Testo completoAbstract (sommario):
Low-pressure exhaust gas recirculation systems are capable of increasing fuel efficiency of spark-ignition engines; however, they introduce control challenges. The low available pressure differential that drives exhaust gas recirculation flow, along with the significant pressure pulsations in the exhaust environment of a turbocharged engine hamper the accuracy of feed-forward estimation models. For that reason, feedback measurements are required in an effort to increase prediction accuracy. Additionally, the accumulation of deposits in the exhaust gas recirculation system and the aging of the valve, change the flow characteristics over time. Under these considerations, an adaptation algorithm is developed which handles both short-term (operating-point-dependent errors) and long-term (system aging) corrections for exhaust gas recirculation flow estimation. The algorithm is based on an extended Kalman filter for joint state and parameter estimation and uses the output of an intake oxygen sensor to adjust the feed-forward prediction by creating an online adaptation map. Two different exhaust gas recirculation estimation models are developed and coupled with the adaptation algorithm. The performance of the algorithm for both estimation models is evaluated in real-time through transient experiments with a turbocharged spark-ignition engine. It is demonstrated that this methodology is capable of creating an adaptation map which captures system aging, while also reduces the estimation bias by more than four times resulting in a prediction error of less than 1%. Finally, this approach proves to be a valuable tool that can significantly reduce offline calibration efforts for such models.
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Gitzhofer, K. "Reduction of Gaseous Boron Compounds in the Waste Gas of Glass Melting Furnaces". Advanced Materials Research 39-40 (aprile 2008): 641–46. http://dx.doi.org/10.4028/www.scientific.net/amr.39-40.641.
Testo completoAbstract (sommario):
For boron containing glasses, you have to consider a gaseous fraction in the exhaust gas besides the particulate boron compounds. Within the framework of a research project finished in the year 2005 investigations into the emission of particulate and gaseous boron compounds were carried out on 18 glass melting furnaces with boron containing batch. The plants are different with regard to the molten glasses, furnace type, type of firing as well as downstream emission control technologies. The precipitation of particulate boron compounds is unproblematic. The precipitation of gaseous boron compounds is clearly more difficult and further measures have to be taken in respect of the effective precipitation. In a current follow up project, especially the reduction potential of gaseous boron compounds is investigated through the installation of a high temperature sorption stage (injection of fine-ground glass raw materials into the exhaust gas flow behind the superstructure at exhaust gas temperatures of 1400 °C) and/or the injection of alkaline solutions into the waste gas at lower temperatures. Investigations in the exhaust gas of E-glass melters were carried out successfully. Reduction rates of more than 95 % could be proved for gaseous boron compounds. The activities are supported by thermo-chemical calculations in the run up and during the measurements.
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Ikeda, Yuji, e Nobuyuki Kawahara. "Measurement of Cyclic Variation of the Air-to-Fuel Ratio of Exhaust Gas in an SI Engine by Laser-Induced Breakdown Spectroscopy". Energies 15, n. 9 (21 aprile 2022): 3053. http://dx.doi.org/10.3390/en15093053.
Testo completoAbstract (sommario):
Temporally and spatially resolved laser-induced breakdown spectroscopy (LIBS) was applied to a four-stroke, single-cylinder test engine’s cyclic exhaust gas to demonstrate engine performance. The LIBS technique provided quantitative air-to-fuel ratio (A/F) measurements by generating localized breakdown plasma during the compression and exhaust strokes. The results showed that the timing and duration settings of the emission energy ionization and molecular spectra affect the intensity peaks. Optimum measurements performed between 200 ns and 10 ms after breakdown resulted in observed atomic spectra of CI (248 nm), Hβ (485 nm), Hα (656 nm), NI (745, 824 nm), and OI (777, 844 nm). The intensities of CI (248 nm) and Hα (656 nm) decreased with increasing A/F, whereas the intensity ratios of NI and OI remained constant. A decrease in the intensity ratio of C/O and Hα/O was observed as the A/F increased. This study is a major step toward defining a means of using LIBS to control the A/F ratio in gasoline engines by focusing on the exhaust gas rather than the flame.
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Ganguli, Ranjan, e Budhadipta Dan. "Trend Shift Detection in Jet Engine Gas Path Measurements Using Cascaded Recursive Median Filter With Gradient and Laplacian Edge Detector". Journal of Engineering for Gas Turbines and Power 126, n. 1 (1 gennaio 2004): 55–61. http://dx.doi.org/10.1115/1.1635400.
Testo completoAbstract (sommario):
Trend shift detection is posed as a two-part problem: filtering of the gas turbine measurement deltas followed by the use of edge detection algorithms. Measurement deltas are deviations in engine gas path measurements from a “good” baseline engine and are a key health signal used for gas turbine performance diagnostics. The measurements used in this study are exhaust gas temperature, low rotor speed, high rotor speed and fuel flow, which are called cockpit measurements and are typically found on most commercial jet engines. In this study, a cascaded recursive median (RM) filter, of increasing order, is used for the purpose of noise reduction and outlier removal, and a hybrid edge detector that uses both gradient and Laplacian of the cascaded RM filtered signal are used for the detection of step change in the measurements. Simulated results with test signals indicate that cascaded RM filters can give a noise reduction of more than 38% while preserving the essential features of the signal. The cascaded RM filter also shows excellent robustness in dealing with outliers, which are quite often found in gas turbine data, and can cause spurious trend detections. Suitable thresholding of the gradient edge detector coupled with the use of the Laplacian edge detector for cross checking can reduce the system false alarms and missed detection rate. Further reduction in the trend shift detection false alarm and missed detection rate can be achieved by selecting gas path measurements with higher signal-to-noise ratios.