scholarly journals Catalyst Conversion Rates Measurement on Engine Fueled with Compressed Natural Gas (CNG) Using Different Operating Temperatures

Mechanika ◽  
2021 ◽  
Vol 27 (6) ◽  
pp. 492-497
Author(s):  
Dariusz SZPICA ◽  
Marcin DZIEWIĄTKOWSKI
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Injection System ◽  
Compression Ignition ◽  
Low Carbon ◽  
Compression Ignition Engine ◽  
Compressed Natural Gas ◽  
Compression Ignition Engines ◽  
Conversion Rates ◽  
Lower Temperature

Further restrictions on the use of compression-ignition engines in transportation are prompting the search for adaptations to run on other fuels. One of the most popular alternative fuels is Compressed Natural Gas (CNG), which due to its low carbon content can be competitive with classical fuels. This paper presents the results of testing a Cummins 6BT compression ignition engine that has undergone numerous modifications to convert to CNG power. The sequential gas injection system and the ignition system were installed in this engine. The compression ratio was also lowered from 16.5 to 11.5 by replacing the pistons. Tests conducted on an engine dynamometer were to show the differences in emission and conversion in the catalyst of hydrocarbons contained in the exhaust gases. Two structurally different catalysts operating at different exhaust temperatures (400 and 500)±2.5°C were used. The catalyst operating at 500±2.5°C showed a 23.5% higher conversion rate than the catalyst operating at a lower temperature in the range of the speed range tested. Also the external indicators, such as power and torque for the case of higher operating temperature took values over 70% higher. The research is one of the stages of a comprehensive assessment of the possibility of adaptation of compression ignition engines to CNG-only fueling.

scholarly journals EFFECT OF CNG IN A FUEL DOSE ON THE COMBUSTION PROCESS OF A COMPRESSION-IGNITION ENGINE

Transport ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Maciej Mikulski ◽  
Sławomir Wierzbicki
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Diesel Oil ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Compression Ignition Engines ◽  
Main Component

Currently, one of the major trends in the research of contemporary combustion engines involves the potential use of alternative fuels. Considerable attention has been devoted to methane, which is the main component of Natural Gas (NG) and can also be obtained by purification of biogas. In compression-ignition engines fired with methane or Compressed Natural Gas (CNG), it is necessary to apply a dual-fuel feeding system. This paper presents the effect of the proportion of CNG in a fuel dose on the process of combustion. The recorded time series of pressure in a combustion chamber was used to determine the repeatability of the combustion process and the change of fuel compression-ignition delay in the combustion chamber. It has been showed that NG does not burn completely in a dual-fuel engine. The best conditions for combustion are ensured with higher concentrations of gaseous fuel. NG ignition does not take place simultaneously with diesel oil ignition. Moreover, if a divided dose of diesel is injected, NG ignition probably takes place at two points, as diesel oil.

Optimum Combustion Chamber Geometry for a Compression Ignition Engine Retrofitted to Run Using Compressed Natural Gas (CNG)

2013 ◽  
Vol 315 ◽  
pp. 552-556 ◽  
Author(s):  
Shahrul Azmir Osman ◽  
Ahmad Jais Alimin ◽  
V.S. Liong
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Negative Impact ◽  
Petroleum Products ◽  
Compression Ignition Engine ◽  
Compressed Natural Gas ◽  
Engine Cylinder ◽  
The Impact

The use of natural gas as an alternative fuels are motivated from the impact in deteriorating quality of air and the energy shortage from petroleum products. Through retrofitting, CI engine runs on CNG, will be able to reduce the negative impact mainly on the use of petroleum products. However, this required the modification of the combustion chamber geometry by reducing the compression ratio to value that suits combustion of CNG. In this present studies, four different shapes and geometries of combustion chamber were designed and simulate using CFD package powered by Ansys workbench, where k-ε turbulence model was used to predict the flow in the combustion chamber. The results of turbulence kinetic energy, velocity vectors and streamline are presented. The enhancement of air-fuel mixing inside the engine cylinder can be observed, where the design with re-entrance and lower center projection provide better results compared to other combustion geometries designs.

Operation of a Compression Ignition Engine with a HEUI Injection System on Natural Gas with Diesel Pilot Injection

1999 ◽  
Author(s):  
Talus Park ◽  
Richard J. Atkinson ◽  
Nigel Clark ◽  
Michael L. Traver ◽  
Christopher M. Atkinson
Keyword(s):  
Natural Gas ◽  
Injection System ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Compression Ignition Engine

Development of compressed natural gas/diesel dual-fuel turbocharged compression ignition engine

2003 ◽  
Vol 217 (9) ◽  
pp. 839-845 ◽  
Author(s):  
Liu Shenghua ◽  
Wang Ziyan ◽  
Ren Jiang
Keyword(s):  
Natural Gas ◽  
Operating Conditions ◽  
Dual Fuel ◽  
Boost Pressure ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Compressed Natural Gas ◽  
Ci Engine ◽  
Heavy Duty Diesel ◽  
Reduce Emissions

A natural gas and diesel dual-fuel turbocharged compression ignition (CI) engine is developed to reduce emissions of a heavy-duty diesel engine. The compressed natural gas (CNG) pressure regulator is specially designed to feed back the boost pressure to simplify the fuel metering system. The natural gas bypass improves the engine response to acceleration. The modes of diesel injection are set according to the engine operating conditions. The application of honeycomb mixers changes the flowrate shape of natural gas and reduces hydrocarbon (HC) emission under low-load and lowspeed conditions. The cylinder pressures of a CI engine fuelled with diesel and dual fuel are analysed. The introduction of natural gas makes the ignition delay change with engine load. Under the same operating conditions, the emissions of smoke and NOx from the dual-fuel engine are both reduced. The HC and CO emissions for the dual-fuel engine remain within the range of regulation.

scholarly journals Ecological aspects of using mixtures of canola oil with n-hexane in diesel engine

2021 ◽  
Author(s):  
Rafał Longwic ◽  
Przemyslaw Sander ◽  
Dawid Tatarynow
Keyword(s):  
Canola Oil ◽  
Injection System ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
The Road ◽  
Common Rail Injection System ◽  
Compression Ignition Engines ◽  
Common Rail Injection ◽  
On The Road ◽  
Main Components

The article discusses the results of research on the use of canola oil and canola oil with the addition of n-hexane in a compression-ignition engine. An engine with a Common Rail injection system was tested in real traffic conditions on the road and on a chassis dynamometer. The tested fuels were fed to the engine by an additional fuel supply system. An analysis of the effect of the addition of n-hexane on the emission of the main components of toxic exhaust gases was carried out. The proposed solution may contribute to extending the service life of currently used compression ignition engines due to the improvement of the ecological properties of this type of drive sources.

Lessons From the Conversion of a Heavy-Duty Compression Ignition Engine to Natural Gas Spark Ignition Operation

2020 ◽  
Author(s):  
Jinlong Liu ◽  
Christopher Ulishney ◽  
Cosmin E. Dumitrescu
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Volume Ratio ◽  
Spark Ignition ◽  
Point Of View ◽  
Injection System ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Lean Burn ◽  
Engine Efficiency

Abstract Partial conversion of the large inventory of compression-ignition engines to natural-gas (NG) spark-ignition lean-burn operation can reduce U.S. dependence on imported petroleum and enhance national energy security. This paper describes some of the observations made during such an engine conversion and proposes some solutions to alleviate some of the potential issues. The engine conversion in this study consisted from replacing the diesel injector with a spark plug and adding a port fuel injection system for NG delivery. The results indicated that the retrofitted engine performed reliably at lean-burn conditions, despite the different combustion characteristics compared to conventional SI engines. However, the squish region will trap an important fuel fraction (∼30%) and experience less-optimal burning conditions, hence a slower burning rate. This affected the engine efficiency and increased the unburned hydrocarbon and carbon monoxide emissions. From a combustion point of view, the operation of such converted engines can be optimized by increasing the bowl-to-squish volume ratio, optimizing the piston shape (e.g., by removing the central protrusion and avoiding 90-degree edges inside the bowl). The original compression ratio may also need to be reduced to avoid knocking. Moreover, direct gas injection and/or intake charging will increase the volumetric efficiency, which will benefit engine efficiency and emissions.

scholarly journals Implementing Natural Gas in a Compression Ignition Cycle Using Noble Gas Addition

2019 ◽  
Author(s):  
Martia Shahsavan ◽  
Mohammadrasool Morovatiyan ◽  
Mammadbaghir Baghirzade ◽  
John Hunter Mack
Keyword(s):  
Natural Gas ◽  
Numerical Study ◽  
Noble Gas ◽  
Cetane Number ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Low Carbon ◽  
Compression Ignition Engine ◽  
Optimal Operating ◽  
Auto Ignition

Natural gas is known as a relatively clean fossil fuel due to its low carbon to hydrogen ratio compared to other transportation fuels, which yields a reduction of carbon monoxide, carbon dioxide, and unburned hydrocarbons emissions. However, it has a low cetane number, which makes it a difficult fuel for use in compression ignition engines. A potential solution for this issue can be adding small amounts of argon, as a noble gas with a low specific heat to modify the intake conditions. In this numerical study, a commercial compression ignition engine has been modeled to evaluate the auto-ignition of natural gas with the modified intake conditions. Different amounts of argon added to the intake air are examined in order to attain the optimal operating conditions. A detailed chemistry solver is implemented on a 53-species chemical kinetics mechanism to calculate the rate constants. The results show that compression ignition of natural gas can be achieved by adding small amounts of argon to the intake air. It drastically increases the in-cylinder temperature and pressure near TDC, which enables the auto-ignition of the injected natural gas. Moreover, it leads to the reduction in ignition delay and heat release rate, and expands the combustion duration. Emissions analysis indicates that NOx and CO2 can be significantly diminished by increasing the amount of argon in the intake composition. This study introduces an efficient and clean compression ignition engine fueled with natural gas running in optimal operating conditions using argon addition to the intake.

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