scholarly journals Investigation of Burn Duration and NO Emission in Lean Mixture with CNG and Gasoline

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4432 ◽  
Author(s):  
Doğan ◽  
Kutlar ◽  
Javadzadehkalkhoran ◽  
Demirci
Keyword(s):  
Natural Gas ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
High Compression Ratio ◽  
Compressed Natural Gas ◽  
Lean Mixture ◽  
Cyclic Variations ◽  
Time Cycle ◽  
Exhaust Gas Emissions ◽  
No Emissions

The results of experiments performed by gasoline and natural gas fuels in a single cylinder research engine were evaluated in this study. The main objective of this study is to compare exhaust gas emissions, efficiency, and burn durations for both fuels in stoichiometric and lean mixture. At the same time, cycle to cycle variation in these operating conditions should not exceed an acceptable value. In the ultra-lean mixture, gasoline fuel exceeded this determined limit before Compressed Natural Gas (CNG). Therefore, the reduction in NO was restricted by cyclic variations. In combustion analysis, although the burn duration of the gasoline in stoichiometric conditions was shorter than CNG, this situation reversed in favor of CNG in the ultra-lean mixtures. Contrary to some studies in the literature, the spark advance and ignition delay for CNG were the same or shorter than gasoline in this study. The primary reasons for this change are the high compression ratio and the different combustion chamber geometry. The increase in turbulence intensity has different effects on CNG and gasoline. As a result, it has been observed that NO emissions can meet the limits without a loss of efficiency for this engine operated with CNG under the ultra-lean mixture.

Effects of Compressed Natural Gas (CNG) Injector Position on Intake Manifold towards Diesel-CNG Dual Fuel (DDF) Engine Performance

2014 ◽  
Vol 70 (1) ◽  
Author(s):  
A. Supee ◽  
R. Mohsin ◽  
Z. A. Majid ◽  
M. I. Raiz
Keyword(s):  
Diesel Engine ◽  
Kinetic Energy ◽  
Natural Gas ◽  
Diesel Fuel ◽  
Engine Performance ◽  
Intake Manifold ◽  
Dual Fuel ◽  
Exhaust Gas ◽  
Compressed Natural Gas ◽  
Exhaust Gas Emissions

In Diesel-CNG (Compressed Natural Gas) Dual Fuel (DDF) system, CNG is generally inducted in the intake manifold by CNG injector which is mounted on the intake manifold whereas diesel fuel is directly injected into engine cylinder using existing diesel fuel injector system. Status quo of optimum CNG injector position on intake manifold will  provide better gaseous fuel mixing quality, produce high turbulence kinetic energy and thus improve the performance of the diesel engine under DDF system. Thus, under full load condition at 2750 rpm, the engine performance and exhaust gas emissions tests such as nitric oxides (NOx), carbon dioxide (CO2), carbon monoxide (CO) and hydrocarbon (HC) were conducted on a diesel engine under DDF system for optimization of CNG injector position. Four CNG injector position on intake manifold were selected and optimum position of CNG injector was found to be at "position 2" which results in higher power output and less exhaust gas emissions. Further analysis by Computational Fluid Dynamics (CFD) shows that CNG injector at "position 2" exhibit better quality of homogeneous CNG-air mixture and higher turbulence kinetic energy compared to other position. Based on the findings, an optimization of CNG injector position on intake manifold provide promising modification method due to the simple, cheaper and commercially acceptable.

Combustion characteristics of compressed natural gas/diesel dual-fuel turbocharged compressed ignition engine

2003 ◽  
Vol 217 (9) ◽  
pp. 833-838 ◽  
Author(s):  
Liu Shenghua ◽  
Zhou Longbao ◽  
Wang Ziyan ◽  
Ren Jiang
Keyword(s):  
Natural Gas ◽  
Ignition Delay ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Dual Fuel ◽  
Compressed Natural Gas ◽  
Delay Effects ◽  
Low Load ◽  
Performance And Emissions ◽  
Ci Engine

The combustion characteristics of a turbocharged natural gas and diesel dual-fuelled compression ignition (CI) engine are investigated. With the measured cylinder pressures of the engine operated on pure diesel and dual fuel, the ignition delay, effects of pilot diesel and engine load on combustion characteristics are analysed. Emissions of HC, CO, NOx and smoke are measured and studied too. The results show that the quantity of pilot diesel has important effects on the performance and emissions of a dual-fuel engine at low-load operating conditions. Ignition delay varies with the concentration of natural gas. Smoke is much lower for the developed dual-fuel engine under all the operating conditions.

scholarly journals Modeling of Three-Way Catalyst Dynamics for a Compressed Natural Gas Engine during Lean–Rich Transitions

2019 ◽  
Vol 9 (21) ◽  
pp. 4610 ◽  
Author(s):  
Dario Di Maio ◽  
Carlo Beatrice ◽  
Valentina Fraioli ◽  
Pierpaolo Napolitano ◽  
Stefano Golini ◽  
...  
Keyword(s):  
Steady State ◽  
Natural Gas ◽  
Catalytic Converter ◽  
Operating Conditions ◽  
Oxygen Storage ◽  
Continuous Control ◽  
Engine Exhaust ◽  
Compressed Natural Gas ◽  
The Impact ◽  
Three Way Catalyst

The main objective of the present research activity was to investigate the effect of very fast composition transitions of the engine exhaust typical in real-world driving operating conditions, as fuel cutoff phases or engine misfire, on the aftertreatment devices, which are generally very sensitive to these changes. This phenomenon is particularly evident when dealing with engines powered by natural gas, which requires the use of a three-way catalyst (TWC). Indeed, some deviations from the stoichiometric lambda value can interfere with the catalytic converter efficiency. In this work, a numerical “quasi-steady” model was developed to simulate the chemical and transport phenomena of a specific TWC for a compressed natural gas (CNG) heavy-duty engine. A dedicated experimental campaign was performed in order to evaluate the catalyst response to a defined λ variation pattern of the engine exhaust stream, thus providing the data necessary for the numerical model validation. Tests were carried out to reproduce oxygen storage phenomena that make catalyst behavior different from the classic steady-state operating conditions. A surface reaction kinetic mechanism concerning CH4, CO, H2, oxidation and NO reduction has been appropriately calibrated at different λ values with a step-by-step procedure, both in steady-state conditions of the engine work plan and during transient conditions, through cyclical and consecutive transitions of variable frequency between rich and lean phases. The activity also includes a proper calibration of the reactions involving cerium inside the catalyst in order to reproduce oxygen storage and release dynamics. Sensitivity analysis and continuous control of the reaction rate allowed evaluating the impact of each of them on the exhaust composition in several operating conditions. The proposed model predicts tailpipe conversion/formation of the main chemical species, starting from experimental engine-out data, and provides a useful tool to evaluate the catalyst’s performance.

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.

A Numerical Investigation of the Cooling Effect of Compressed Natural Gas Throttling on Engine Delivery Ratio

1999 ◽  
Vol 121 (1) ◽  
pp. 121-128
Author(s):  
Y. Yacoub ◽  
L. Marbun ◽  
R. Bata
Keyword(s):  
Heat Exchanger ◽  
Natural Gas ◽  
Thermodynamic Model ◽  
Theoretical Study ◽  
Operating Conditions ◽  
Cooling Effect ◽  
Delivery Ratio ◽  
Pressure Regulation ◽  
Compressed Natural Gas ◽  
Fuel Delivery

A theoretical study was conducted to investigate the cooling effect of throttling compressed natural gas during the pressure regulation process. The concept of using this effect in cooling down the induction air was investigated. A thermodynamic model was developed for a typical fuel delivery system used on a vehicle fueled with compressed natural gas. The model was based on a set of integral conservation laws applied to each component of the fueling system. Several heat exchanging arrangements between the throttled gas and the inlet air were examined. The effect of the added heat exchanger on engine delivery ratio was examined for different engine sizes as well as for different operating conditions. An increase of 1 to 2.5% in engine delivery ratio was predicted due to the added heat exchanger.

scholarly journals The influence of natural gas additive on the smoke level generated by diesel engines

2015 ◽  
Vol 161 (2) ◽  
pp. 78-88
Author(s):  
Zdzisław STELMASIAK ◽  
Jerzy LARISCH ◽  
Dariusz PIETRAS
Keyword(s):  
Natural Gas ◽  
Engine Speed ◽  
Diesel Oil ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Chassis Dynamometer ◽  
Natural Gas Engines ◽  
Smoke Opacity ◽  
Small Additive ◽  
Selection Of

The paper presents the results of investigations performed on a Fiat 1.3 MultiJet engine fueled with natural gas (CNG) and diesel oil. The primary aim was to determine the influence of a small additive of natural gas on the exhaust gas opacity under variable engine operating conditions. The tests were performed for the engine work points n–Mo (engine speed– torque) reproducing the NEDC cycle. The selection of the work points was carried out according to the criterion of greatest share in the NEDC homologation test, covering the entire engine field of work used in the realization of the test on a chassis dynamometer. In the tests, the authors applied different energy shares of natural gas in the range 15–35.6%. The smoke opacity was analyzed in the FSN and mass scales [mg/m3 ]. The results of the investigations may be used in the design of electronic controllers for natural gas engines and in the adaptation engines to CNG fueling.

Evaluation of the Integral toxicity of Exhaust Gases of a Diesel Engine Operating on Natural Gas and Alcohol Emulsions

2019 ◽  
Vol 23 (9) ◽  
pp. 60-65 ◽  
Author(s):  
V.A. Likhanov ◽  
O.P. Lopatin
Keyword(s):  
Particulate Matter ◽  
Diesel Engine ◽  
Natural Gas ◽  
Diesel Exhaust ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Gas Recirculation ◽  
Total Hydrocarbons ◽  
Weight Coefficients

The results of studies of the integral toxicity of exhaust gases of a diesel engine operating on natural gas and alcohol emulsions are presented. At the same time, the regimes characterizing the specific toxicity of a diesel engine under its operating conditions were determined, and emissions of toxic components on these regimes were determined taking into account their weight coefficients. The results of research specific toxic diesel exhaust toxicity indicators, in accordance with the requirements of UNECE Regulation No. 49, show that when a diesel engine operates on natural gas with exhaust gas recirculation and an ethanol-fuel emulsion, the content of nitrogen oxides (NOx) and carbon dioxide (CO) in the exhaust gases conforms to "EURO 3", particulate matter – "EURO 5", total hydrocarbons (CHx) – "EURO 2". When the diesel engine is running on a methanol-fuel emulsion, the content of NOx, СНx and CO in the exhaust gases complies with the standards "EURO 3", particulate matter – "EURO 5".

scholarly journals SI engine performance, lubricant oil deterioration, and emission: A comparison of liquid and gaseous fuel

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402093045
Author(s):  
Muhammad Usman ◽  
Muhammad Wajid Saleem ◽  
Syed Saqib ◽  
Jamal Umer ◽  
Ahmad Naveed ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Natural Gas ◽  
Specific Energy ◽  
Alternative Fuels ◽  
Specific Energy Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Compressed Natural Gas ◽  
Lubricant Oil ◽  
Brake Power

Considering the importance of alternative fuels in IC engines for environment safety, compressed natural gas has been extensively employed in SI engines. However, scarce efforts have been made to investigate the effect of compressed natural gas on engine lubricant oil for a long duration. In this regard, a comprehensive analysis has been made on the engine performance, emissions, and lubricant oil conditions using gasoline ( G)92 and compressed natural gas at different operating conditions using reliable sampling methods. The key parameters of the engine performance like brake power and brake-specific energy consumption were investigated at 80% throttle opening within 1500–4500 range of r/min. For the sake of emission tests, speed was varied uniformly by varying the load at a constant throttle. Furthermore, the engine was run at high and low loads for lubricant oil comparison. Although compressed natural gas showed a decrease in brake-specific energy consumption (7.94%) and emissions content, ( G)92 performed relatively better in the case of brake power (39.93% increase). Moreover, a significant improvement was observed for wear debris, lubricant oil physiochemical characteristics, and additives depletion in the case of compressed natural gas than those of ( G)92. The contents of metallic particles were decreased by 23.58%, 36.25%, 42.42%, and 66.67% for iron, aluminum, copper, and lead, respectively, for compressed natural gas.

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