G-07 Three dimensional numerical studies on combustion process in natural gas - light gas oil dual-fuel diesel engine

2016 ◽  
Vol 2016.69 (0) ◽  
pp. 273-274
Author(s):  
Atsushi KUBOTA ◽  
Jin KUKSAKA ◽  
Akira KIKUSATO ◽  
Yoshinori ISHII ◽  
Toshiaki ADACHI
Author(s):  
Yasufumi Yoshimoto ◽  
Eiji Kinoshita

This paper investigates the performance, exhaust emissions, and combustion characteristics of a dual fuel diesel engine fueled by CNG (compressed natural gas) as the main fuel. The experiments used standard ignition fuels prepared by n-hexadecane and heptamethylnonane which are used to define the ignitability of diesel combustion, and focused on the effects of fuels with better ignitability than ordinary gas oil such as fuels with higher cetane numbers, 70 and 100. Compared with gas oil ignition, a standard ignition fuel with C.N. 100 showed shorter ignition delays, and lower NOx exhaust concentrations, and engine noise. The results also showed that regardless of ignition fuel, misfiring occurred when the CNG supply was above 75%. While the CNG ratio where misfiring occurs lowered somewhat with increasing C.N., the combustion stability (defined as the standard deviation in the cycle to cycle variation of IMEP divided by the mean value of IMEP) was little influenced. In summary, the results show that the influence of the ignitability on the engine performance and emission characteristics of the dual fuel operation is relatively small when the ignition fuel has C.N., and similar to or higher than ordinary gas oil.


2018 ◽  
Vol 9 (1) ◽  
pp. 2137-2150
Author(s):  
Nono Sukirno ◽  
Dwi Prasetyo ◽  
Moh. Aziz Rohman

Dual Fuel Diesel Engine (Mesin Bahan Bakar Ganda) merupakan mesin denganpemanfaatan dua bahan bakar dalam proses pembakarannya untuk memperoleh tenaga kerjapada mesin. Jenis bahan bakar yang digunakan meliputi bahan bakar Methane Gas (CH4)dan MGO (Marine Gas Oil). Methane (CH4) dihasilkan dari Vapour Cargo Tank LNG(Liquified Natural Gas). Tujuan dari penelitian ini adalah untuk mengetahui apa sajapenyebab tingginya suhu gas buang terhadap kinerja Dual Fuel Diesel Engine di MV.Tangguh Palung dengan menggunakan metode analisis data Fault Tree Analysis. Darianalisis data penelitian di hasilkan beberapa rumusan masalah yaitu, faktor-faktor yangdapat menyebabkan tingginya suhu gas buang pada Dual Fuel Diesel Engine adalahkurangnya suplai udara pembakaran dalam ruang pembakaran mesin, komposisipembakaran yang tidak sesuai antara bahan bakar minyak dan gas, serta suhu Engine Roomyang terlalu panas. Dampak yang di timbulkan adalah kerusakan pada komponen-komponenpermesinan dan penurunan kinerja dari Dual Fuel Diesel Engine. Untuk mengatasipenurunan kerja pada Dual Fuel Diesel Engine adalah dengan melaksanakan perawatan danperbaikan pada setiap komponen permesinan yang mengalami masalah dan kerusakan sesuaidengan Running Hours dan Instruction Manual Book.


Author(s):  
A. Gharehghani ◽  
M. Mirsalim ◽  
A. Jazayeri ◽  
R. Hosseini

Low Temperature combustion (LTC) strategies are capable of simultaneous reduction in NOx and particulate matter (PM) emissions. However, this combustion process generally leads to higher HC and CO emissions together with more cyclic variation (unstable combustion) especially at light engine loads. These emissions could drastically be reduced using certain alternative fuels like natural gas and biodiesel in LTC or PCI combustion engines. In the present research, a single cylinder compression ignition engine has been modified to operate in dual fuel mode with natural gas injection into the intake manifold as the main fuel and biodiesel as the pilot fuel to ignite the gas/air mixture. The combustion characteristics, engine performance and exhaust emissions of the reactivity controlled compression ignition (RCCI) dual fueled CNG/biodiesel engine are investigated and compared with the conventional diesel engine mode at various load conditions. The analysis of the results revealed that biodiesel as the high reactivity fuel in RCCI mode leads to higher in-cylinder pressure together with shorter heat release rate duration, compared to the common diesel engine. Experimental results indicated that combining the low temperature combustion concept and alternative fuels (e.g. biodiesel and naturals gas) causes lower levels of unburned hydrocarbon (UHC) and carbon monoxide (CO) as well as nitrogen oxide (NOx) emissions.


2021 ◽  
Vol 9 (2) ◽  
pp. 123
Author(s):  
Sergejus Lebedevas ◽  
Lukas Norkevičius ◽  
Peilin Zhou

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.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1342
Author(s):  
Van Chien Pham ◽  
Jae-Hyuk Choi ◽  
Beom-Seok Rho ◽  
Jun-Soo Kim ◽  
Kyunam Park ◽  
...  

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.


Author(s):  
Shuonan Xu ◽  
David Anderson ◽  
Mark Hoffman ◽  
Robert Prucka ◽  
Zoran Filipi

Energy security concerns and an abundant supply of natural gas in the USA provide the impetus for engine designers to consider alternative gaseous fuels in the existing engines. The dual-fuel natural-gas diesel engine concept is attractive because of the minimal design changes, the ability to preserve a high compression ratio of the baseline diesel, and the lack of range anxiety. However, the increased complexity of a dual-fuel engine poses challenges, including the knock limit at a high load, the combustion instability at a low load, and the transient response of an engine with directly injected diesel fuel and port fuel injection of compressed natural gas upstream of the intake manifold. Predictive simulations of the complete engine system are an invaluable tool for investigations of these conditions and development of dual-fuel control strategies. This paper presents the development of a phenomenological combustion model of a heavy-duty dual-fuel engine, aided by insights from experimental data. Heat release analysis is carried out first, using the cylinder pressure data acquired with both diesel-only and dual-fuel (diesel and natural gas) combustion over a wide operating range. A diesel injection timing correlation based on the injector solenoid valve pulse widths is developed, enabling the diesel fuel start of injection to be detected without extra sensors on the fuel injection cam. The experimental heat release trends are obtained with a hybrid triple-Wiebe function for both diesel-only operation and dual-fuel operation. The ignition delay period of dual-fuel operation is examined and estimated with a predictive correlation using the concept of a pseudo-diesel equivalence ratio. A four-stage combustion mechanism is discussed, and it is shown that a triple-Wiebe function has the ability to represent all stages of dual-fuel combustion. This creates a critical building block for modeling a heavy-duty dual-fuel turbocharged engine system.


2014 ◽  
Vol 525 ◽  
pp. 227-231 ◽  
Author(s):  
Min Xiao ◽  
Chun Long Feng

In order to solve the problem of Diesel natural gas dual fuel engine, such as power reduction, low charging efficiency, the conception of diesel engine fueled with pilot-ignited directly-injected liquefied natural gas is put forward. On the basis of this theory, a medium speed diesel of the marine is refitted into dual fuel engine, in order to keep original power, decrease the temperature of combustion and reduce emission. The LNG injection timing, duration of LNG injection and the different ratios the pilot diesel to total energy are studied the method of AVL FIRE software. Conclusions are as follows: When the different ratios pilot diesel to total energy is 0.5%, the engine can not work; Delaying the LNG injection timing, shortening the LNG injection duration and choose the right ratios pilot diesel to total energy can reach the indicated power of original machine, and the NOx emissions level will be greatly reduced.


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