A method to precisely control the diesel substitution rate of diesel-natural gas dual fuel engine

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.

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Diesel-Like Efficiency Using CNG/Diesel Dual-Fuel Combustion

Volume 1: Large Bore Engines; Fuels; Advanced Combustion ◽

10.1115/icef2015-1147 ◽

2015 ◽

Cited By ~ 2

Author(s):

Karthik Nithyanandan ◽

Jiaxiang Zhang ◽

Yuqiang Li ◽

Xiangyu Meng ◽

Robert Donahue ◽

...

Keyword(s):

Natural Gas ◽

Substitution Rate ◽

Fuel Combustion ◽

Operating Conditions ◽

Pollutant Emissions ◽

Dual Fuel ◽

Injection Timing ◽

Diesel Combustion ◽

Diesel Injection ◽

Dual Fuel Combustion

The use of natural gas in compression ignition 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, 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 (UHC), carbon monoxide (CO), nitrogen oxides (NOx) and soot. The goal of these experiments was to maximize the efficiency. This was done as follows — the 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. 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 injection 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.

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Effects of the substitution rate of natural gas on the combustion and emission characteristics in a dual-fuel engine under full load

Advances in Mechanical Engineering ◽

10.1177/1687814017747158 ◽

2017 ◽

Vol 9 (12) ◽

pp. 168781401774715 ◽

Cited By ~ 6

Author(s):

Meng Lyu ◽

Chunhua Zhang ◽

Xiaofeng Bao ◽

Jiangyong Song ◽

Zemin Liu

Keyword(s):

Natural Gas ◽

Substitution Rate ◽

Dual Fuel ◽

Emission Characteristics ◽

Full Load

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ANALYSIS OF LAMBDA, ANGLE OF INJECTION AND SUBSTITUTION RATE IN HYDROCARBONS EMISSIONS IN DIESEL CYCLE ENGINE OPERATING IN DUAL FUEL MODE

10.26678/abcm.cobem2017.cob17-2104 ◽

2017 ◽

Author(s):

Silvio Cesar de Lima Nogueira ◽

Stephan Hennings Och ◽

Luís Mauro Moura

Keyword(s):

Substitution Rate ◽

Dual Fuel ◽

Diesel Cycle

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Development of environment-friendly dual fuel pulverized coal-natural gas combustion technology for the co-firing power plant boiler: Experimental and numerical analysis

Energy ◽

10.1016/j.energy.2021.120550 ◽

2021 ◽

Vol 228 ◽

pp. 120550

Author(s):

Iman Rahimipetroudi ◽

Kashif Rashid ◽

Je Bok Yang ◽

Sang Keun Dong

Keyword(s):

Numerical Analysis ◽

Power Plant ◽

Natural Gas ◽

Dual Fuel ◽

Environment Friendly ◽

Gas Combustion ◽

Power Plant Boiler ◽

Combustion Technology ◽

Natural Gas Combustion ◽

Plant Boiler

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Investigation of Effect on Environmental Performance of Using LNG as Fuel for Engines in Seaport Tugboats

Journal of Marine Science and Engineering ◽

10.3390/jmse9020123 ◽

2021 ◽

Vol 9 (2) ◽

pp. 123

Author(s):

Sergejus Lebedevas ◽

Lukas Norkevičius ◽

Peilin Zhou

Keyword(s):

Diesel Engine ◽

Natural Gas ◽

Baltic Sea ◽

Impact Assessment ◽

Fuel Consumption ◽

Dual Fuel ◽

Nox Emissions ◽

The Baltic Sea ◽

Emission Analysis ◽

The Baltic

Decarbonization of ship power plants and reduction of harmful emissions has become a priority in the technological development of maritime transport, including ships operating in seaports. Engines fueled by diesel without using secondary emission reduction technologies cannot meet MARPOL 73/78 Tier III regulations. The MEPC.203 (62) EEDI directive of the IMO also stipulates a standard for CO2 emissions. This study presents the results of research on ecological parameters when a CAT 3516C diesel engine is replaced by a dual-fuel (diesel-liquefied natural gas) powered Wartsila 9L20DF engine on an existing seaport tugboat. CO2, SO2 and NOx emission reductions were estimated using data from the actual engine load cycle, the fuel consumption of the KLASCO-3 tugboat, and engine-prototype experimental data. Emission analysis was performed to verify the efficiency of the dual-fuel engine in reducing CO2, SO2 and NOx emissions of seaport tugboats. The study found that replacing a diesel engine with a dual-fuel-powered engine led to a reduction in annual emissions of 10% for CO2, 91% for SO2, and 65% for NOx. Based on today’s fuel price market data an economic impact assessment was conducted based on the estimated annual fuel consumption of the existing KLASCO-3 seaport tugboat when a diesel-powered engine is replaced by a dual-fuel (diesel-natural gas)-powered engine. The study showed that a 33% fuel costs savings can be achieved each year. Based on the approved methodology, an ecological impact assessment was conducted for the entire fleet of tugboats operating in the Baltic Sea ports if the fuel type was changed from diesel to natural gas. The results of the assessment showed that replacing diesel fuel with natural gas achieved 78% environmental impact in terms of NOx emissions according to MARPOL 73/78 Tier III regulations. The research concludes that new-generation engines on the market powered by environmentally friendly fuels such as LNG can modernise a large number of existing seaport tugboats, significantly reducing their emissions in ECA regions such as the Baltic Sea.

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CFD Study and Experimental Validation of a Dual Fuel Engine: Effect of Engine Speed

Energies ◽

10.3390/en14144307 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4307

Author(s):

Roberta De Robbio ◽

Maria Cristina Cameretti ◽

Ezio Mancaruso ◽

Raffaele Tuccillo ◽

Bianca Maria Vaglieco

Keyword(s):

Natural Gas ◽

High Performance ◽

Engine Speed ◽

Pollutant Emissions ◽

Dual Fuel ◽

Automotive Market ◽

Light Duty ◽

Viable Solution ◽

Dual Fuel Engines ◽

Gas Ratio

Dual fuel engines induce benefits in terms of pollutant emissions of PM and NOx together with carbon dioxide reduction and being powered by natural gas (mainly methane) characterized by a low C/H ratio. Therefore, using natural gas (NG) in diesel engines can be a viable solution to reevaluate this type of engine and to prevent its disappearance from the automotive market, as it is a well-established technology in both energy and transportation fields. It is characterized by high performance and reliability. Nevertheless, further improvements are needed in terms of the optimization of combustion development, a more efficient oxidation, and a more efficient exploitation of gaseous fuel energy. To this aim, in this work, a CFD numerical methodology is described to simulate the processes that characterize combustion in a light-duty diesel engine in dual fuel mode by analyzing the effects of the changes in engine speed on the interaction between fluid-dynamics and chemistry as well as when the diesel/natural gas ratio changes at constant injected diesel amount. With the aid of experimental data obtained at the engine test bench on an optically accessible research engine, models of a 3D code, i.e., KIVA-3V, were validated. The ability to view images of OH distribution inside the cylinder allowed us to better model the complex combustion phenomenon of two fuels with very different burning characteristics. The numerical results also defined the importance of this free radical that characterizes the areas with the greatest combustion activity.

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A Numerical Study on the Combustion Process and Emission Characteristics of a Natural Gas-Diesel Dual-Fuel Marine Engine at Full Load

Energies ◽

10.3390/en14051342 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1342

Author(s):

Van Chien Pham ◽

Jae-Hyuk Choi ◽

Beom-Seok Rho ◽

Jun-Soo Kim ◽

Kyunam Park ◽

...

Keyword(s):

Natural Gas ◽

Combustion Process ◽

Simulation Software ◽

Dual Fuel ◽

Injection Timing ◽

Emission Characteristics ◽

Cylinder Pressure ◽

Marine Engine ◽

Full Load ◽

Simulation Results

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.

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