A multilevel study on the influence of natural gas substitution rate on combustion mode and cyclic variation in a diesel/natural gas dual fuel engine

Fuel ◽  
2021 ◽  
Vol 294 ◽  
pp. 120499
Author(s):  
Zhongshu Wang ◽  
Xiaodong Fu ◽  
Dan Wang ◽  
Yun Xu ◽  
Guizhi Du ◽  
...  
Keyword(s):  
Natural Gas ◽  
Substitution Rate ◽  
Dual Fuel ◽  
Cyclic Variation ◽  
Combustion Mode ◽  
Multilevel Study

scholarly journals Design of new clean and efficient combustion mode and thermodynamics research using NSGA-II algorithm

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2699-2706
Author(s):  
Guoqing Shen
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Fuel Consumption ◽  
Consumption Rate ◽  
Thermodynamic Characteristics ◽  
Dual Fuel ◽  
Combustion Mode ◽  
Nsga Ii ◽  
Fuel Consumption Rate ◽  
Efficient Combustion

In order to study a new clean and efficient combustion mode, which can relieve the pressure of traditional energy and ensure low emissions, in this study, a diesel/natural gas dual fuel engine is designed by non-dominant sorting genetic algorithm (NSGA-?), and its thermodynamic characteristics are studied. The WP10.290 Diesel engine is modified into a diesel/natural gas dual fuel engine. The emissions of harmful substances and thermal efficiency of the modified engine under different working conditions are compared. The combustion chamber structure and adaptability between combustion chamber and injection parameters are optimized by using NSGA-II algorithm and CFD software. The results show that the emission of NOx and CH4 and the fuel consumption rate can be reduced simultaneously by using the composite combustion model compared with the original engine. When the CH4 emission is close to zero, the fuel consumption rate decreases obviously, and NOx slightly increases. When the angle between the injection holes is 141.57? the amount of NOx in the cylinder is large. When the injection advance angle is 21.91?CA, the pressure in the cylinder is the highest, the CH4 production is the lowest, the NOx production is higher, and the oxygen content in the combustion mixture is less. The NOx production is the lowest. diesel/natural gas dual fuel engine can ensure efficient combustion while reducing emissions. In this study, the performance of the dual fuel engine at various speeds can be further studied, which can provide theoretical support for the design of diesel/natural gas dual fuel engine.

Combustion and Emission Characteristics of a CI Engine Operating in Diesel-1-Butanol/CNG Dual Fuel Mode With Low and High CNG Substitution Rates in Light Load Operation

2016 ◽  
Author(s):  
Xiangyu Meng ◽  
Yuanxu Li ◽  
Karthik Nithyanandan ◽  
Wuqiang Long ◽  
Chia-Fon F. Lee
Keyword(s):  
Thermal Efficiency ◽  
Substitution Rate ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Combustion Mode ◽  
Substitution Rates ◽  
Low Load ◽  
Pilot Fuel ◽  
Dual Fuel Combustion

Dual-fuel combustion mode with direct injection of diesel as the pilot fuel and port injection of compressed natural gas (CNG) in compression ignition (CI) engines has been widely investigated to comply with the latest emission regulations. The diesel-CNG dual-fuel combustion mode shows some potential to decrease NOx and soot emissions simultaneously, while it reveals a lower thermal efficiency compared to the pure diesel combustion mode under low load condition. The purpose of the current study is to investigate the possibility of using diesel blended with 1-butanol as the pilot fuel to enhance the engine performance and reduce emissions. Three pilot fuels — B0 (pure diesel), B10 (90% diesel and 10% 1-butanol by volume) and B20 (80% diesel and 20% 1-butanol) with the CNG substitution rates of 50% and 80% were compared at an engine speed of 1200 rpm. The experiments were conducted by sweeping the pilot fuel injection timing from −3 to −18 ° CA ATDC with an equivalent total energy (∼5 bar IMEP). The results illustrated that, for the 50% CNG substitution rate, the dual-fuel operation mode revealed a higher indicated thermal efficiency (ITE) under low load conditions, and B10 can significantly improve the ITE due to the shorter combustion duration. The emission results of B10 showed that it obtained lower THC and CO emissions, but a slightly higher NOx emission. For the 80% CNG substitution rate, the results presented lower ITE, higher THC and lower NOx emissions, comparatively.

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.

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

2015 ◽  
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.

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

2017 ◽  
Vol 9 (12) ◽  
pp. 168781401774715 ◽  
Author(s):  
Meng Lyu ◽  
Chunhua Zhang ◽  
Xiaofeng Bao ◽  
Jiangyong Song ◽  
Zemin Liu
Keyword(s):  
Natural Gas ◽  
Substitution Rate ◽  
Dual Fuel ◽  
Emission Characteristics ◽  
Full Load

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

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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