scholarly journals The Effect of Natural Gas Substitution Ratio and Diesel Injection Timing on Accuracy of In-cylinder Pressure Prediction DNN Model from Vibration Signal in a CNG-Diesel Dual-Fuel Engine

2021 ◽  
Vol 29 (10) ◽  
pp. 909-919
Author(s):  
Gyeonggon Kim ◽  
Chansoo Park ◽  
Wooyeong Kim ◽  
Jeeyeon Jeon ◽  
Miyeon Jeon ◽  
...  
Keyword(s):  
Natural Gas ◽  
Vibration Signal ◽  
Dual Fuel ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Diesel Injection ◽  
Substitution Ratio

Experimental Study on Combustion and Performance of a Natural Gas-Diesel Dual-Fuel Engine at Different Pilot Diesel Injection Timing

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Jiantong Song ◽  
Zhixin Feng ◽  
Jiangyi Lv ◽  
Hualei Zhang
Keyword(s):  
Natural Gas ◽  
Pressure Rise ◽  
Mean Value ◽  
Dual Fuel ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Diesel Injection ◽  
Peak Cylinder Pressure ◽  
Crank Angle ◽  
And Performance

Abstract The pilot diesel injection timing (θ) significantly affects the combustion and performance of dual-fuel (DF) engines. In order to optimize the θ of a natural gas-diesel DF engine, the influence of θ on combustion, cyclic variation, and performance of a diesel engine fueled with natural gas piloted by diesel under full load at 1200 rpm was investigated. The results indicate that, with the advance in θ, the cylinder pressure, rate of pressure rise (ROPR), and heat release rate (HRR) increase first and then decrease. The mean value of peak cylinder pressure (pmax) rises and the standard deviation increases first and then decreases. The distribution of the crank angle of peak cylinder pressure (φ(pmax)) scatters and approaches the top dead center. The coefficient of variation (COV) in pmax decreases first and then increases while the COV in φ(pmax) obviously increases. The brake power increases first and then decreases while the brake specific fuel consumption (b.s.f.c.) reduces first and then rises. The CO2 and NOx emissions rise first and then reduce while smoke emission decreases first and then increases, but the CO and HC rise.

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

Energies ◽  
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.

Combustion Performance and Unburned Hydrocarbon Emissions of a Natural Gas–Diesel Dual Fuel Engine at a Low Load Condition

2017 ◽  
Author(s):  
Hongsheng Guo ◽  
Brian Liko ◽  
Luis Luque ◽  
Jennifer Littlejohns
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Load Condition ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Unburned Hydrocarbon ◽  
Diesel Injection ◽  
Dual Fuel Engines ◽  
Dual Fuel Combustion

The combustion of natural gas reduces fuel cost and generates less emissions of carbon dioxide and particulate matter than diesel and gasoline. Replacing diesel by natural gas in internal combustion engines is of great interest for transportation and stationary power generation. Dual fuel combustion is an efficient way to burn natural gas in internal combustion engines. In natural gas–diesel dual fuel engines, unburned hydrocarbon emissions increase with increasing natural gas fraction. Many studies have been conducted to improve the performance of natural gas–diesel dual fuel engines and reported the performance of combustion and emissions of regulated pollutants and total unburned hydrocarbon at various engine operating strategies. However, little has been reported on the emissions of different unburned hydrocarbon components. In this paper, an experimental investigation was conducted to investigate the combustion performance and emissions of various unburned hydrocarbon components, including methane, ethane, ethylene, acetylene, propylene, formaldehyde, acetaldehyde and benzaldehyde, at a low engine load condition. The operating conditions, such as engine speed, load, intake temperature and pressure, were well controlled during the experiment. The combustion and emissions performance of pure diesel and natural gas–diesel dual fuel combustion were compared. The effect of diesel injection timing was analyzed. The results show that appropriately advancing diesel injection timing to form a homogeneous charge compression ignition-like combustion is beneficial to natural gas–diesel dual fuel combustion at low load conditions. The emissions of different unburned hydrocarbon components changed in dual fuel combustion, with emissions of some unburned hydrocarbon components being primarily due to the combustion of natural gas, while those of others being more related to diesel combustion.

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.

Dual-Fueling of a Prechamber Diesel Engine With Natural Gas

1985 ◽  
Vol 107 (4) ◽  
pp. 914-921 ◽  
Author(s):  
S. Song ◽  
P. G. Hill
Keyword(s):  
Energy Consumption ◽  
Diesel Engine ◽  
Natural Gas ◽  
Consumption Rate ◽  
Dual Fuel ◽  
Combustion Mechanism ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Energy Consumption Rate ◽  
Diesel Operation

The feasibility of dual-fuel operation with natural gas in a prechamber diesel engine was studied with special emphasis on fuel consumption and cylinder pressure development. The effects of air restriction, pilot diesel flow rate, and injection timing were also investigated. Near full load the fuel energy consumption rate was close to that of straight diesel operation though at part load (in the absence of air restriction) the fuel energy consumption rate was relatively high. In the absence of injection timing adjustment the maximum power output of dual-fuel operation was severely limited by the maximum cylinder pressure. Retarding the injection timing is effective in reducing the maximum cylinder pressure to a safe level. The analysis of apparent energy release indicates the differences in combustion mechanism between auto-ignition of diesel fuel in straight diesel operation and propagation of flame fronts in dual-fuel operation.

Diesel and Compressed Natural Gas Dual Fuel Engine Operating Envelope for Heavy Duty Application

2014 ◽  
Author(s):  
Andrew de Tablan
Keyword(s):  
Natural Gas ◽  
Diesel Fuel ◽  
The United States ◽  
Dual Fuel ◽  
Boost Pressure ◽  
Cylinder Pressure ◽  
Heavy Duty ◽  
Substitution Rates ◽  
Diesel Injection ◽  
Peak Cylinder Pressure

The abundance of natural gas in the United States and low price relative to diesel fuel has generated interest in dual fuel engines where natural gas is substituted for diesel fuel. The factors limiting the natural gas (NG) substitution rates are: minimum diesel injector pulse width, cycle-to-cycle variation in net indicated mean effective pressure (NIMEP), engine knock, peak cylinder pressure, compression ratio, boost pressure and lean air/fuel limits leading to misfire among others. The objective of this study was to explore the highest natural gas substitution for a commercially available heavy duty diesel engine for several of the 13 Mode European Stationary Cycle (ESC) and US EPA Supplementary Emissions Tests (SET) speeds and loads while maintaining acceptable engine performance levels. A heavy duty 2012 Navistar MaxxForce 13® engine was retrofitted to accommodate dual-fuel operation. The engine was operated over several different speeds and loads to determine the possible NG substitution rates at different diesel injection timings, diesel injection pressures and equivalence ratios, while maintaining combustion phasing. The data showed that dual fuel operation at high NG percentages was stable over several speeds and loads with brake thermal efficiencies comparable to 100% diesel operation. The introduction of NG generally demonstrated reductions in peak cylinder pressure and cylinder pressure rise rate at a given speed and load point. Increases in hydrocarbon and greenhouse gas emissions and a decrease in nitrogen oxides were observed during dual-fuel operation.

Combustion Performance and Unburned Hydrocarbon Emissions of a Natural Gas–Diesel Dual Fuel Engine at a Low Load Condition

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Hongsheng Guo ◽  
Brian Liko ◽  
Luis Luque ◽  
Jennifer Littlejohns
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Load Condition ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Unburned Hydrocarbon ◽  
Diesel Injection ◽  
Dual Fuel Engines ◽  
Dual Fuel Combustion

The combustion of natural gas reduces fuel cost and generates less emissions of carbon dioxide and particulate matter (PM) than diesel and gasoline. Replacing diesel by natural gas in internal combustion engines is of great interest for transportation and stationary power generation. Dual fuel combustion is an efficient way to burn natural gas in internal combustion engines. In natural gas–diesel dual fuel engines, unburned hydrocarbon emissions increase with increasing natural gas fraction. Many studies have been conducted to improve the performance of natural gas–diesel dual fuel engines and reported the performance of combustion and emissions of regulated pollutants and total unburned hydrocarbon at various engine operating strategies. However, little has been reported on the emissions of different unburned hydrocarbon components. In this paper, an experimental investigation was conducted to investigate the combustion performance and emissions of various unburned hydrocarbon components, including methane, ethane, ethylene, acetylene, propylene, formaldehyde, acetaldehyde, and benzaldehyde, at a low engine load condition. The operating conditions, such as engine speed, load, intake temperature, and pressure, were well controlled during the experiment. The combustion and emissions performance of pure diesel and natural gas–diesel dual fuel combustion were compared. The effect of diesel injection timing was analyzed. The results show that appropriately advancing diesel injection timing to form a homogeneous charge compression ignition (HCCI)-like combustion is beneficial to natural gas–diesel dual fuel combustion at low load conditions. The emissions of different unburned hydrocarbon components changed in dual fuel combustion, with emissions of some unburned hydrocarbon components being primarily due to the combustion of natural gas, while those of others being more related to diesel combustion.

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.

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