scholarly journals The effects of natural gas composition on conventional dual-fuel and reactivity-controlled compression ignition combustion in a heavy-duty diesel engine

2021 ◽  
pp. 146808742098404
Author(s):  
Vinícius B Pedrozo ◽  
Xinyan Wang ◽  
Wei Guan ◽  
Hua Zhao
Keyword(s):  
Natural Gas ◽  
Ghg Emissions ◽  
Transport Sector ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Reactivity Controlled Compression Ignition ◽  
Actuation System ◽  
Methane Slip

The use of natural gas (NG) in dual-fuel heavy-duty engines has the potential to reduce pollutant and greenhouse gas (GHG) emissions from the transport sector when compared to the conventional diesel engines. However, NG composition and methane slip are of interest because both can adversely affect the benefits of NG as an alternative fuel, especially when considering GHG emissions. Therefore, this study experimentally investigated the effects of NG fuel properties on the performance and emissions of both conventional dual-fuel and reactivity-controlled compression ignition (RCCI) engine operations. Three different gas mixtures were selected to simulate typical NG compositions available in the world market, with methane numbers (MN) of 80.9, 87.6 and 94.1. These fuels were tested in a single-cylinder compression ignition engine operating at 0.6, 1.2 and 1.8 MPa net indicated mean effective pressure (IMEP). A high-pressure common rail system allowed for the use of various diesel injection strategies while a variable valve actuation system enabled the effective compression ratio to be adjusted via late intake valve closing (LIVC). The RCCI combustion was found to be more sensitive to changes in MN than the conventional NG-diesel dual-fuel operation. The gas mixture with the lowest MN reduced both total unburned hydrocarbons emissions and methane slip at the expense of higher nitrogen oxides (NOx) emissions. The effects of MN on the net indicated efficiency were more significant at 0.6 MPa IMEP, yielding differences of up to 4.9% between the RCCI operations with the lowest and highest MN fuels. Overall, this work revealed that the combination of the RCCI combustion and LIVC can achieve up to 80% lower methane slip and NOx emissions and relatively higher net indicated efficiency than the conventional dual-fuel regime, independent of the NG composition.

Natural Gas for High Load Dual-Fuel Reactivity Controlled Compression Ignition (RCCI) in Heavy-Duty Engines

2014 ◽  
Author(s):  
N. Ryan Walker ◽  
Martin L. Wissink ◽  
Dan A. DelVescovo ◽  
Rolf D. Reitz
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Maximum Load ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Engine Operation ◽  
Reactivity Controlled Compression Ignition ◽  
Market Growth ◽  
Load Limit ◽  
Fuel Blending

Reactivity controlled compression ignition (RCCI) has been shown to be capable of providing improved engine efficiencies coupled with the benefit of low emissions via in-cylinder fuel blending. Much of the previous body of work has studied the use of gasoline as the premixed low-reactivity fuel. However, there is interest in exploring the use of alternative fuels in advanced combustion strategies. Due to the strong market growth of natural gas as a fuel in both mobile and stationary applications, a study on the use of methane for RCCI combustion was performed. Single cylinder heavy-duty engine experiments were undertaken to examine the operating range of the RCCI combustion strategy with methane/diesel fueling, and was compared against gasoline/diesel RCCI operation. The experimental results show a significant load extension of RCCI engine operation with methane/diesel fueling compared to gasoline/diesel fueling. For gasoline/diesel fueling, a maximum load of 6.9 bar IMEPg at CA50 = 0° aTDC and 7.0 bar IMEPg at CA50 = 4° aTDC was obtained without use of EGR. For methane/diesel fueling a maximum load of 15.4 bar IMEPg at CA50 = 0° aTDC and 17.3 bar IMEPg at CA50 = 4° aTDC was achieved, showing the effectiveness of the use of methane in extending the load limit for RCCI engine operation.

Natural Gas for High Load Dual-Fuel Reactivity Controlled Compression Ignition in Heavy-Duty Engines

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
N. Ryan Walker ◽  
Martin L. Wissink ◽  
Dan A. DelVescovo ◽  
Rolf D. Reitz
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Maximum Load ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Engine Operation ◽  
Reactivity Controlled Compression Ignition ◽  
Market Growth ◽  
Indicated Mean Effective Pressure ◽  
Fuel Blending

Reactivity controlled compression ignition (RCCI) has been shown to be capable of providing improved engine efficiencies coupled with the benefit of low emissions via in-cylinder fuel blending. Much of the previous body of work has studied the use of gasoline as the premixed low-reactivity fuel. However, there is interest in exploring the use of alternative fuels in advanced combustion strategies. Due to the strong market growth of natural gas as a fuel in both mobile and stationary applications, a study on the use of methane for RCCI combustion was performed. Single cylinder heavy-duty engine experiments were undertaken to examine the operating range of the RCCI combustion strategy with methane/diesel fueling and were compared against gasoline/diesel RCCI operation. The experimental results show a significant load extension of RCCI engine operation with methane/diesel fueling compared to gasoline/diesel fueling. For gasoline/diesel fueling, a maximum load of 6.9 bar gross indicated mean effective pressure (IMEPg) at CA50 = 0 deg aTDC (after top dead center) and 7.0 bar IMEPg at CA50 = 4 deg aTDC was obtained without use of exhaust gas recirculation (EGR). For methane/diesel fueling, a maximum load of 15.4 bar IMEPg at CA50 = 0 deg aTDC and 17.3 bar IMEPg at CA50 = 4 deg aTDC was achieved, showing the effectiveness of the use of methane in extending the load limit for RCCI engine operation.

A detail simulation of reactivity controlled compression ignition combustion strategy in a heavy-duty diesel engine run on natural gas/diesel fuel

2017 ◽  
Vol 19 (7) ◽  
pp. 774-789 ◽  
Author(s):  
Mojtaba Ebrahimi ◽  
Mohammad Najafi ◽  
Seyed Ali Jazayeri ◽  
Ali Reza Mohammadzadeh
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Diesel Fuel ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Engine Operation ◽  
Reactivity Controlled Compression Ignition ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Compression Ignition Combustion

The aim of this study is to investigate in details the effects of a number of combustion parameters to optimize the reactivity controlled compression ignition operation running on natural gas and diesel fuel. In the present work, a single-cylinder heavy-duty diesel engine with a specially modified bathtub piston bowl profile for reactivity controlled compression ignition operation is studied and simulated through commercial software. A broad load range from 5.6 to 13.5 bar indicated mean effective pressure at a constant engine speed of 1300 r/min, fixed amount of diesel fuel mass, and with no exhaust gas recirculation is considered. The results from the developed model confirm that the model can accurately simulate the reactivity controlled compression ignition combustion. Also, by focusing on the time of formation of certain important radicals in combustion, the start of combustion and the time of natural gas dissociation are accurately predicted. Furthermore, the influence of some parameters such as different diesel fuel injection strategies, intake temperature, and intake pressure on the reactivity controlled compression ignition combustion is evaluated and the limitation of the engine operation at low temperature combustion is investigated.

Comparison of Diesel Pilot Ignition (DPI) and Reactivity Controlled Compression Ignition (RCCI) in a Heavy-Duty Engine

2015 ◽  
Author(s):  
N. Ryan Walker ◽  
Flavio D. F. Chuahy ◽  
Rolf D. Reitz
Keyword(s):  
Natural Gas ◽  
Equivalence Ratio ◽  
Internal Combustion Engines ◽  
Combustion Regime ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Reactivity Controlled Compression Ignition ◽  
Combustion Performance ◽  
Rich Condition ◽  
Combustion Regimes

Due to growing interest in utilizing natural gas as an alternative fuel in internal combustion engines, a study on the use of natural gas for dual-fuel combustion strategies in a heavy-duty engine was performed to examine the diesel pilot ignition (DPI) and reactivity controlled compression ignition (RCCI) combustion strategies. In Part 1 of this work, the transition between the DPI and RCCI combustion regimes was studied via the direct control of the SOI timing. At the relatively rich condition of ϕ = 0.72, the performance of both combustion strategies was comparable. In Part 2 of this work, the effect of the equivalence ratio on each combustion regime was examined. It was observed that at richer conditions the performance of each combustion regime was similar. However as the conditions became leaner, the performance improved for RCCI combustion and was degraded for DPI combustion. In Part 3 of this work, the effect of fueling rate was explored at a relatively lean operating condition (ϕ = 0.52). It was seen that the fueling rate has little effect on the combustion performance as the engine load was increased. The strong influence of the equivalence ratio on the combustion performance of the RCCI and DPI combustion strategies indicates the both combustion regimes are recommended to engine applications with air handling systems which generate relatively rich in-cylinder conditions; for engine applications with air handling systems which allow for relatively lean in-cylinder conditions, the RCCI combustion regime is recommended.

Numerical evaluation of the effect of methane number on natural gas and diesel dual-fuel combustion

2018 ◽  
Vol 20 (4) ◽  
pp. 405-423 ◽  
Author(s):  
Zhenkuo Wu ◽  
Christopher J Rutland ◽  
Zhiyu Han
Keyword(s):  
Natural Gas ◽  
Ignition Delay ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Gas Composition ◽  
Reactivity Controlled Compression Ignition ◽  
Dual Fuel Combustion ◽  
Compression Ignition Combustion ◽  
Methane Number

Natural gas and diesel dual-fuel combustion is a promising technology for efficiently utilizing natural gas in a compression ignition engine. Natural gas composition varies depending on the geographical source, which affects engine performance. The methane number is an indicator of natural gas fuel quality to assess the variation in composition. In this study, the influences of methane number on natural gas/diesel dual-fuel combustion were numerically examined using computational fluid dynamic simulations. The differences between natural gases with the same methane number but different components were also compared. Two dual-fuel combustion strategies, diesel pilot ignition, and reactivity controlled compression ignition were evaluated. The results show that for both diesel pilot ignition and reactivity controlled compression ignition, the ignition delay increases and the combustion duration decreases as the methane number is increased. The retarded trend of ignition of reactivity controlled compression ignition is more significant than that of diesel pilot ignition, while the decreased trend in combustion duration is less significant. To understand this trend, a chemical kinetics study of ignition delay characteristic of natural gas and n-heptane mixture was conducted. The result reveals that introducing ethane, propane, or an ethane–propane mixture into pure methane shortens the ignition delay in the entire temperature range. However, for the methane and n-heptane mixture, adding ethane, or propane, or an ethane–propane mixture shortens the ignition delay in the high temperature range, while increases the ignition delay in the low temperature range. These observations in combination with the analysis of air–fuel mixture formation and combustion provide the evidence to interpret the different ignition and combustion behaviors between diesel pilot ignition and reactivity controlled compression ignition combustion. In addition, a temperature A-factor sensitivity study was carried out to explain the result of the chemical kinetics study. Furthermore, the responses of emissions to methane number were also investigated. The results show that for diesel pilot ignition, the hydrocarbon and carbon monoxide emissions decrease with the decreased methane number. However, for reactivity controlled compression ignition, the variations of hydrocarbon and carbon monoxide emissions with the methane number are not so obvious as for diesel pilot ignition combustion. For both diesel pilot ignition and reactivity controlled compression ignition combustion, the nitrogen oxides emissions show a strong dependence on combustion phasing rather than natural gas composition. Overall, to control diesel pilot ignition combustion, the methane number should be considered together with other parameters. However, attention should be paid to other control parameters for the reactivity controlled compression ignition combustion. The engine performance of reactivity controlled compression ignition is not sensitive to the variation of natural gas composition, so it can adapt to the natural gas from different sources.

Combustion and Greenhouse Gas Emissions of a Natural Gas-Diesel Dual Fuel Engine at Low and High Load Conditions

2019 ◽  
Author(s):  
Hongsheng Guo ◽  
Brian Liko ◽  
Jennifer Littlejohns
Keyword(s):  
Natural Gas ◽  
Co2 Emissions ◽  
Ghg Emissions ◽  
Engine Performance ◽  
Dual Fuel ◽  
N2o Emissions ◽  
Low Carbon ◽  
Heavy Duty ◽  
Renewable Natural Gas ◽  
Load Conditions

Abstract The Paris agreement is exerting pressure on industries that generate significant greenhouse gas (GHG) emissions, such as transportation. Electrification can help reduce GHG emissions from light duty vehicles, but it is unfeasible for heavy duty vehicles that are predominately powered by diesel engines. Fuel switching from diesel to low carbon fuels is a more practical way helping reduce GHG emissions from heavy duty vehicles. Natural gas and renewable natural gas are low carbon or renewable fuels that generate much less carbon dioxide (CO2) emissions than diesel during combustion. Natural gas/renewable natural gas – diesel dual fuel combustion is an efficient way to replace diesel by natural gas/renewable natural gas in heavy duty diesel engines. This paper reports an experimental investigation on combustion and GHG emissions of a heavy duty natural gas – diesel dual fuel engine at different load/speed conditions. The variation in the effect of natural gas fraction on engine performance with changing engine load was compared and analyzed. Nitrous oxide (N2O), nitrogen oxides (NOx), methane (CH4) and CO2 emissions were experimentally investigated and analyzed. The results revealed that the effect of natural gas fraction on engine performance changed with varying engine load and speed condition. N2O emissions from a dual fuel engine changed with increasing natural gas fraction, but the effect of N2O emissions on overall GHG emissions was not significant. However, CH4 emissions contributed significantly to the overall GHG emissions in a dual fuel engine, especially at low load conditions.

Development of a Compression Ignition Heavy Duty Pilot-Ignited Natural Gas Fuelled Engine for Low NOx Emissions

2004 ◽  
Author(s):  
D. Goudie ◽  
M. Dunn ◽  
S. R. Munshi ◽  
E. Lyford-Pike ◽  
J. Wright ◽  
...  
Keyword(s):  
Natural Gas ◽  
Nox Emissions ◽  
Compression Ignition ◽  
Heavy Duty

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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