scholarly journals Excess Air Ratio Management in a Diesel Engine with Exhaust Backpressure Compensation

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6701
Author(s):  
Piotr Kasprzyk ◽  
Jacek Hunicz ◽  
Arkadiusz Rybak ◽  
Michał S. Gęca ◽  
Maciej Mikulski

The paper investigates the operation of a wideband universal exhaust gas oxygen (UEGO) sensor in a diesel engine under elevated exhaust backpressure. Although UEGO sensors provide the excess air ratio feedback signal primarily in spark ignition engines, they are also used in diesel engines to facilitate low-emission combustion. The excess air signal is used as an input for the fuel mass observer, as well as to run the engine in the low-emission regime and enable smokeless acceleration. To ensure a short response time and individual cylinder control, the UEGO sensor can be installed upstream of a turbocharger; however, this means that the exhaust gas pressure affects the measured oxygen concentration. Therefore, this study determines the sensor’s sensitivity to the exhaust pressure under typical conditions for lean burn low-emission diesel engines. Identification experiments are carried out on a supercharged single-cylinder diesel engine with an exhaust system mimicking the operation of the turbocharger. The apparent excess air measured with the UEGO sensor is compared to that obtained in a detailed exhaust gas analysis. The comparison of reference and apparent signals shows that the pressure compensation correlations used in gasoline engines do not provide the correct values for diesel engine conditions. Therefore, based on the data analysis, a new empirical formula is proposed, for which the suitability for lean burn diesel engines is verified.

Author(s):  
A.V. Nelidkin ◽  
◽  
S.N. Borychev ◽  
D.O. Oleynik ◽  
◽  
...  

To ensure high quality and productive work of employ-ees, it is necessary to achieve the target parameters of the microclimate and to exclude harmful and toxic substances in the atmosphere of the working area of agricultural prem-ises of a closed volume and air exchange. The main rea-son for the distortion of the air-gas regime of the room is the use of agricultural machines in closed industrial prem-ises (warehouses, storage facilities, livestock facilities, etc.). As a result, there is a decrease in the quality of prod-ucts and working conditions at agricultural enterprises, as well as a reduction in the operational life of structures. To-day, in agricultural machinery, diesel engines are most often used as power units which, unlike gasoline engines are more economical, and also reduce the harmful impact on the environment. But, despite this, the operation of die-sel engines still causes the accumulation of harmful com-ponents in the atmosphere of the room which negatively affects the health of the staff. The analysis of the designs of devices for exhaust gas purificationof internal combus-tion engines revealed the problems that affect the efficien-cy of the purification. The most significant problems are as following: large weight and dimensions, reduced efficiency of the neutralizers when the engine is running at modes close to the nominal ones, and large gas-dynamic re-sistance. To solve these problems, the design of a device for exhaust gas purificationin diesel engines was devel-oped. The use of this utility model will increase the efficien-cy of the device for exhaust gas purification. It will improve the environmental performance of the diesel engine reduc-ing emissions of harmful substances and soot into the at-mosphere.


2016 ◽  
Vol 7 (5) ◽  
pp. 594-600 ◽  
Author(s):  
Mantas Smolnikovas ◽  
Gintas Viselga ◽  
Greta Viselgaitė ◽  
Algirdas Jasinskas

The article presents an overview of structural evolution of diesel engines’ injection systems, air pollution caused by diesel engines and permissible emission rates. An analytical research on air pollution was also performed. Experimental studies evaluated air pollution during the emission of particulate matter according to diesel engine exploitation time and different constructions emissions. Apžvelgta dyzelinių variklių įpurškimo sistemų konstrukcijų raida, aplinkos oro tarša dyzelinių variklių išmetamosiomis dujomis ir leistinos jų emisijų normos, atlikti analitiniai oro taršos tyrimai. Eksperimentiniais tyrimais įvertinta oro tarša į aplinką išmetamomis kietosiomis dalelėmis iš skirtingų konstrukcijų ir eksploatacijos laiko dyzelinių variklių.


Author(s):  
Yoshifuru Nitta ◽  
Dong-Hoon Yoo ◽  
Sumito Nishio ◽  
Yasuhisa Ichikawa ◽  
Koichi Hirata ◽  
...  

Reductions of Nitrogen oxides (NOx), sulphur oxides (SOx) and carbon dioxide (CO2) emissions have been acknowledged on the global level. The International Maritime Organization (IMO) has developed some mandatory or non-mandatory instruments such as codes, amendments, recommendations or guidelines to strengthen the emissions regulations on ships engaged in international voyage. However, it is difficult to meet the strengthened emissions regulations on the conventional marine diesel engines. Lean burn gas engines have been thus recently attracting attention in the maritime industry. The lean burn gas engines use natural gas as fuel and can simultaneously reduce both NOx and CO2 emissions. On the other hand, since methane is the main component of natural gas, the slipped methane which is the unburned methane emitted from the lean burn gas engines might have a potential impact on global warming. The authors investigated on a ship installed conventional marine diesel engines and lean burn gas engines, and have proposed a C-EGR (combined exhaust gas recirculation) system to reduce the slipped methane from the gas engines and NOx from marine diesel engines. This system consists of a marine diesel engine and a lean burn gas engine, and the exhaust gas emitted from the lean burn gas engine is provided to the intake manifold of the marine diesel engine by a blower installed between both engines. Since exhaust gas from the gas engine including slipped methane, this system could reduce both the NOx from the marine diesel engine and the slipped methane from the lean burn gas engine simultaneously. This paper introduces the details of the proposed C-EGR system, and presents the experimental results of emissions and engine performance characteristics on the C-EGR system. In the experiment, the diesel engine was operated at three load conditions of 25, 50 and 75% along with the propeller load curve. In order to keep the slipped methane concentration constant, the gas engine was operated at a constant load condition of 25%. The intake exhaust gas quantity which is supplied to the diesel engine was adjusted by the blower speed. As a result, it was confirmed that the C-EGR system attained more than 75% reduction of the slipped methane in the intake gas. In addition, the NOx emission from the diesel engine decreased with the effect of the EGR system. Also the fuel consumption of the diesel engine did not increase, because of the methane combustion in the intake gas.


2021 ◽  
Vol 157 (A4) ◽  
Author(s):  
R Grega ◽  
J Homišin ◽  
M Puškár ◽  
J Kul’ka ◽  
J Petróci ◽  
...  

Development of diesel engines is focused on reduction of exhaust gas emissions, increase of efficiency of the fuel mixture combustion and decrease of fuel consumption. Such engines are referred to as low-emission engines. Low- engines trends bring higher engine power outputs, torques and also increase of vibrations and noisiness level. In order to reduce these vibrations of diesel engines, it is necessary to apply different dynamical elements, which are able to increase an adverse impact of exciting amplitudes. One of the results is application of a pneumatic dual-mass flywheel. The pneumatic dual-mass flywheel is a dynamical element that consists of two masses (the primary and the secondary mass), which are jointed together by means of a flexible interconnection. This kind of the flywheel solution enables to change resonance areas of the mechanical system which consequently leads to reduction of vibrations.


2021 ◽  
Vol 12 (4) ◽  
pp. 23-40
Author(s):  
Naresh Kumar Konada ◽  
K.N.S. Suma ◽  
B.B. Ashok Kumar

Increase in energy demand, stringent emission norms and depletion of oil resources led to the discovery of alternative fuels forinternal combustion engines. Many alternative fuels like alcohols, petroleum gas, and compressed natural gas have been alreadycommercialized in the transport sector. In the present work, Pongomia oil and Neem oil are blended with diesel and used as analternate fuel for CI engines. The Pongomia oil and Neem oil can be converted into bio diesel using a chemical process of trans- esterification.Different proportions of fuel blends have been produced by the process of blending bio diesel consisting of 10%, 15%, 20%, 25%, and 30% (B10, B15, B20, B25, B30). The fuel properties of each blend are determined. The load test along with smoke and exhaust gas analysis of 4- Stroke Diesel engine using the blends of Pongomia oil and Neem oil with diesel are done in this study. The performance parameters of an engine are calculated for different blends. The sustainability of using alternate fuels in Diesel engines, especially the potential use of Pongomia oil and Neem oil as biodiesel have been brought to the fore through this work and suitable blends of bio diesel is suggested from the results. Keywords: 4-Stroke Diesel Engine, Pongomia and Neem oil Bo diesel, Performance, Smoke and exhaust gas analysis.


Author(s):  
Fengjun Yan ◽  
Junmin Wang

Fueling control in Diesel engines is not only of significance to the combustion process in one particular cycle, but also influences the subsequent dynamics of air-path loop and combustion events, particularly when exhaust gas recirculation (EGR) is employed. To better reveal such inherently interactive relations, this paper presents a physics-based, control-oriented model describing the dynamics of the intake conditions with fuel injection profile being its input for Diesel engines equipped with EGR and turbocharging systems. The effectiveness of this model is validated by comparing the predictive results with those produced by a high-fidelity 1-D computational GT-Power engine model.


2018 ◽  
Vol 7 (4.36) ◽  
pp. 920
Author(s):  
Byshov N.V ◽  
Bachurin A.N ◽  
Bogdanchikov I.Yu ◽  
Oleynik D.O ◽  
Yakunin Yu.V. ◽  
...  

The aim of the article is to develop a method and a device for reducing the toxicity of exhaust gases of diesel engines and reducing noise taking into account the current mode of operation of the engine. This is done with the help of installing a liquid catalyst (LC) into the exhaust system, ensuring the processes of trapping, chemical bonding and neutralization of toxic components and soot particles in the aerosol chamber while the vortex flow is being processed by a neutralizing solution supplied under pressure. Then the flow is divided into phases and toxic components and soot are separated in the centrifugal swirl drop separator (SDS).The developed and tested design of an exhaust gas cleaning device installed instead of the standard D-120 engine exhaust system and an automated cleaning process control system make it possible to reduce the toxicity of exhaust gases (EG): nitrogen oxides by 40 %, hydrocarbons by 43 % and soot by 70 %. The noise level of its work in enclosed spaces was reduced by 16–22 %. The device also had low gas-dynamic resistance.The investigation methodology is based on the use of modern methods and measuring devices. Exhaust gas tester META “Autotest CO – CH – CO2 – O2 – λ – NOx” was used to measure the toxicity of exhaust gases. To measure smoking at the exhaust of the diesel engine, the opacity meter META-01MP was used. The gas flow velocity was measured with ATT-1004 thermo-anemometer, the noise level of the tractor was recorded with noise and vibration meter VSHV–003–M2, and the fuel consumption with SIRT-1 meter.Theoretical studies were carried out on the basis of the laws of gas dynamics, the modern theory of statistical analysis, and experiment planning techniques. When developing an experimental LC model, dependencies were obtained, which allow to achieve the optimal design and technological parameters of the wet cleaning system for diesel exhaust gases.The optimization of the design parameters and the processing of experimental data were carried out with the help of modern software using the methods of mathematical statistics using computers.The current methods of reducing the toxicity of engines consist primarily in improving the design of engines, in order to influence the nature of the working process, the use of alternative fuels and additives, exhaust gas recirculation, as well as installing various types of exhaust gas catalytic systems. Measures related to the introduction of constructive changes in engines require some major restructuring of the industry, which is difficult to achieve in modern conditions. Alternative fuels have not yet been widely used in agriculture. Therefore, today the most effective and acceptable means of achieving environmental standards is the installation of various mobile catalysts in the exhaust system, as well as devices for trapping soot particles. The use of this exhaust gas cleaning system for diesel engines functioning in enclosed spaces can significantly improve the working conditions of the personnel and have a slight effect on the power and fuel-economic performance of the power unit, reducing the power of the D-120 engine of the T-30 tractor equipped with an upgraded exhaust system when taking external speed characteristics averaged 1.6 %, the torque was 1.5 % and the increase in specific fuel consumption was 1.8 %.In this paper we used materials from scientific publications indexed by bibliographic abstract databases of Scopus and Web of Science.   


Author(s):  
Naeim A. Henein ◽  
Tamer Badawy ◽  
Nilesh Rai ◽  
Walter Bryzik

Advanced electronically controlled diesel engines require a feedback signal to the ECU to adjust different operating parameters and meet demands for power, better fuel economy and low emissions. Different types of in-cylinder combustion sensors are being considered to produce this signal. This paper presents results of an experimental investigation on the characteristics of the ion current in an automotive diesel engine equipped with a common rail injection system. The engine is a 1.9 L, 4-cylinder, direct injection diesel engine. Experiments covered different engine loads and injection pressures. The relationships between the ion current, combustion parameters and engine out NO emissions and opacity are presented. The analysis of the experimental data identified possible sources of the ion current produced in diesel engines.


2013 ◽  
Vol 291-294 ◽  
pp. 1889-1894
Author(s):  
Lei Jiang ◽  
Jun Huang

Urea-SCR catalytic converter can effectively reduce the NOx emission of diesel engines, but meanwhile catalytic converter will cause some pressure loss in the exhaust system, which has negative influences on the engine performances. In this paper, the method of theoretical analysis calculated the pressure loss of the SCR catalytic converter, and designing a new type of exhaust gas pipe. Through the test to meet the design requirements,the results can provide a reference for optimum design of SCR catalytic converters and assembling.


Author(s):  
Alfian Firdiansyah ◽  
Nasrul Ilminnafik ◽  
Agus Triono ◽  
Muh Nurkoyim Kustanto

<p class="02abstracttext"><span lang="IN">A small diesel engine is a machine that has high efficiency but causes a high level of pollution. The most widely used fuel so far is fossil energy which is unrenewable energy. The fruit of the Calophyllum inophyllum plant has great potential to be developed as alternative energy for small diesel engines. In this study, the test fuel used was D100, B100, E5, E10, and E15. The small engine diesel used TG-R180 Diesel with a compression ratio of 20:1 at engine turns 1500, 1800, 2100, and 2400 rpm, and the braking load at a constant prony disc brake is 1,5 kg/cm<sup>2</sup>. The result of the study using E10 fuel can improve engine performance and can reduce the opacity of the exhaust gas. The highest power in the D100 fuel at 2100 rpm is 8,06 PS. The highest thermal efficiency of E10 fuel is 50,29%. The use of Calophyllum inophyllum biodiesel (B100) can reduce exhaust gas opacity in small diesel engines when compared to the use of D100. E10 fuel has the lowest exhaust gas opacity rate of 4,1%.</span></p>


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