An Analysis of Dual-Fuel Combustion of Diesel with Compressed Natural Gas in a Single-Cylinder Engine

2018 ◽  
Author(s):  
Jonathan M. S. Mattson ◽  
Chenaniah Langness ◽  
Christopher Depcik
Keyword(s):  
Natural Gas ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Compressed Natural Gas ◽  
Single Cylinder ◽  
Single Cylinder Engine ◽  
Dual Fuel Combustion

Comparative assessment of engine vibration, combustion, performance and emission characteristics between single and twin-cylinder diesel engines in unifuel and dual-fuel mode

2021 ◽  
pp. 1-39
Author(s):  
Akash Chandrabhan Chandekar ◽  
Sushmita Deka ◽  
Biplab K. Debnath ◽  
Ramesh Babu Pallekonda
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Load Condition ◽  
Alternative Fuel ◽  
Dual Fuel ◽  
Cylinder Pressure ◽  
Compressed Natural Gas ◽  
Single Cylinder ◽  
Engine Vibration ◽  
Single Cylinder Engine

Abstract The persistent efforts among the researchers are being done to reduce emissions by the exploration of different alternative fuels. The application of alternative fuel is also found to influence engine vibration. The present study explores the potential connection between the change of the engine operating parameters and the engine vibration pattern. The objective is to analyse the effect of alternative fuel on engine vibration and performance. The experiments are performed on two different engines of single cylinder and twin-cylinder variants at the load range of 0 to 34Nm, with steps of 6.8Nm and at the constant speed of 1500rpm. The single cylinder engine, fuelled with only diesel mode, is tested at two compression ratios of 16.5 and 17.5. While, the twin-cylinder engine with a constant compression ratio of 16.5, is tested at both diesel unifuel and diesel-compressed natural gas dual-fuel modes. Further, in dual-fuel mode, tests are conducted with compressed natural gas substitutions of 40%, 60% and 80% for given loads and speed. The engine vibration signatures are measured in terms of root mean square acceleration, representing the amplitude of vibration. The combustion parameters considered are cylinder pressure, rate of pressure rise, heat release rate and ignition delay. At higher loads, the vibration amplitude increases along with the cylinder pressure. The maximum peak cylinder pressure of 95bar is found in the case of the single cylinder engine at the highest load condition that also produced a peak vibration of 3219m/s2.

Diesel-Like Efficiency Using Compressed Natural Gas/Diesel Dual-Fuel Combustion

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Karthik Nithyanandan ◽  
Jiaxiang Zhang ◽  
Yuqiang Li ◽  
Xiangyu Meng ◽  
Robert Donahue ◽  
...  
Keyword(s):  
Natural Gas ◽  
Substitution Rate ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Diesel Combustion ◽  
Compressed Natural Gas ◽  
Diesel Injection ◽  
Dual Fuel Combustion ◽  
Ci Engines

The use of natural gas in compression ignition (CI) engines as a supplement to diesel under dual-fuel combustion mode is a promising technique to increase efficiency and reduce emissions. In this study, the effect of dual-fuel operating mode on combustion characteristics, engine performance and pollutant emissions of a diesel engine using natural gas as primary fuel and neat diesel as pilot fuel, has been examined. Natural gas (99% methane) was port injected into an AVL 5402 single cylinder diesel research engine under various engine operating conditions and up to 90% substitution was achieved. In addition, neat diesel was also tested as a baseline for comparison. The experiments were conducted at three different speeds—1200, 1500, and 2000 rpm, and at different diesel-equivalent loads (injection quantity)—15, 20 (7 bar IMEP), and 25 mg/cycle. Both performance and emissions data are presented and discussed. The performance was evaluated through measurements of in-cylinder pressure, power output and various exhaust emissions including unburned hydrocarbons (UHCs), carbon monoxide (CO), nitrogen oxides (NOx), and soot. The goal of these experiments was to maximize the efficiency. This was done as follows—the compressed natural gas (CNG) substitution rate (based on energy) was increased from 30% to 90% at fixed engine conditions, to identify the optimum CNG substitution rate. Then using that rate, a main injection timing sweep was performed. Under these optimized conditions, combustion behavior was also compared between single, double, and triple injections. Finally, a load and speed sweep at the optimum CNG rate and timings were performed. It was found that a 70% CNG substitution provided the highest indicated thermal efficiency (ITE). It appears that dual-fuel combustion has a maximum brake torque (MBT) diesel injection timing for different conditions which provides the highest torque. Based on multiple diesel injection tests, it was found that the conditions that favor pure diesel combustion, also favor dual-fuel combustion because better diesel combustion provides better ignition and combustion for the CNG-air mixture. For 70% CNG dual-fuel combustion, multiple diesel injections showed an increase in the efficiency. Based on the experiments conducted, diesel-CNG dual-fuel combustion is able to achieve similar efficiency and reduced emissions relative to pure diesel combustion. As such, CNG can be effectively used to substitute for diesel fuel in CI engines.

Experimental Investigation of the Natural Gas / Diesel Dual-Fuel Combustion Using a Rapid Compression Machine

2011 ◽  
Author(s):  
Julio C. C. Eg\ausquiza ◽  
Sergio L. Braga ◽  
Carlos V. M. Braga ◽  
Antonio C. S. Villela ◽  
Newton R. Moura
Keyword(s):  
Experimental Investigation ◽  
Natural Gas ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Rapid Compression Machine ◽  
Dual Fuel Combustion ◽  
Rapid Compression

Numerical Simulation of a Large Bore Dual Fuel Marine Engine Using Tabulated Detailed Reaction Mechanisms

2019 ◽  
Author(s):  
Sascha Andree ◽  
Dmitry Goryntsev ◽  
Martin Theile ◽  
Björn Henke ◽  
Karsten Schleef ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Natural Gas ◽  
Chemical Reaction ◽  
Reaction Mechanisms ◽  
Combustion Process ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Start Of Injection ◽  
Flamelet Generated Manifold ◽  
Dual Fuel Combustion

Abstract The simulation of a diesel natural gas dual fuel combustion process is the topic of this paper. Based on a detailed chemical reaction mechanism, which was applied for such a dual fuel combustion, the complete internal combustion engine process was simulated. Two single fuel combustion reaction mechanisms from literature were merged, to consider the simultaneous reaction paths of diesel and natural gas. N-heptane was chosen as a surrogate for diesel. The chemical reaction mechanisms are solved by applying a tabulation method using the software tool AVL Tabkin™. In combination with a Flamelet Generated Manifold (FGM) combustion model, this leads to a reduction of computational effort compared to a direct solving of the reaction mechanism, because of a decoupling of chemistry and flow calculations. Turbulence was modelled using an unsteady Reynolds-Averaged Navier Stokes (URANS) model. In comparison to conventional combustion models, this approach allows for detailed investigations of the complex ignition process of the dual fuel combustion process. The unexpected inversely proportional relationship between start of injection (SOI) and start of combustion (SOC), a later start of injection makes for an earlier combustion of the main load, is only one of these interesting combustion phenomena, which can now be analyzed in detail. Further investigations are done for different engine load points and multiple pilot injection strategies. The simulation results are confirmed by experimental measurements at a medium speed dual fuel single cylinder research engine.

Performance and Emissions Characteristics of Diesel-Ignited Gasoline Dual Fuel Combustion in a Single-Cylinder Research Engine

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
U. Dwivedi ◽  
C. D. Carpenter ◽  
E. S. Guerry ◽  
A. C. Polk ◽  
S. R. Krishnan ◽  
...  
Keyword(s):  
Injection Pressure ◽  
Fuel Combustion ◽  
Injection System ◽  
Dual Fuel ◽  
Heterogeneous Combustion ◽  
Boost Pressure ◽  
Fuel Injector ◽  
Single Cylinder ◽  
Diesel Injection ◽  
Dual Fuel Combustion

Diesel-ignited gasoline dual fuel combustion experiments were performed in a single-cylinder research engine (SCRE), outfitted with a common-rail diesel injection system and a stand-alone engine controller. Gasoline was injected in the intake port using a port-fuel injector. The engine was operated at a constant speed of 1500 rev/min, a constant load of 5.2 bar indicated mean effective pressure (IMEP), and a constant gasoline energy substitution of 80%. Parameters such as diesel injection timing (SOI), diesel injection pressure, and boost pressure were varied to quantify their impact on engine performance and engine-out indicated specific nitrogen oxide emissions (ISNOx), indicated specific hydrocarbon emissions (ISHC), indicated specific carbon monoxide emissions (ISCO), and smoke emissions. Advancing SOI from 30 degrees before top dead center (DBTDC) to 60 DBTDC reduced ISNOx from 14 g/kW h to less than 0.1 g/kW h; further advancement of SOI did not yield significant ISNOx reduction. A fundamental change was observed from heterogeneous combustion at 30 DBTDC to “premixed enough” combustion at 50–80 DBTDC and finally to well-mixed diesel-assisted gasoline homogeneous charge compression ignition (HCCI)-like combustion at 170 DBTDC. Smoke emissions were less than 0.1 filter smoke number (FSN) at all SOIs, while ISHC and ISCO were in the range of 8–20 g/kW h, with the earliest SOIs yielding very high values. Indicated fuel conversion efficiencies were ∼ 40–42.5%. An injection pressure sweep from 200 to 1300 bar at 50 DBTDC SOI and 1.5 bar intake boost showed that very low injection pressures lead to more heterogeneous combustion and higher ISNOx and ISCO emissions, while smoke and ISHC emissions remained unaffected. A boost pressure sweep from 1.1 to 1.8 bar at 50 DBTDC SOI and 500 bar rail pressure showed very rapid combustion for the lowest boost conditions, leading to high pressure rise rates, higher ISNOx emissions, and lower ISCO emissions, while smoke and ISHC emissions remained unaffected by boost pressure variations.

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