Dual-Fuel System for Heavy Duty Truck Engines

2001 ◽  
Author(s):  
Usman Asad ◽  
Umar A. Shafique
Keyword(s):  
Natural Gas ◽  
Engine Performance ◽  
Dual Fuel ◽  
Heavy Duty ◽  
Operating Modes ◽  
Heavy Duty Truck ◽  
Light Load ◽  
Conversion System ◽  
Transportation Applications ◽  
Gas Conversion

Abstract Increasing emphasis on natural gas as a clean, economical and abundant fuel advocates its increasing use in transportation applications. In developing countries like Pakistan and India where, more than 80% of the goods are transported by trucks and where natural gas is available in abundance, development of natural gas conversion systems for heavy-duty truck engines offers a viable option to replace the use of expensive imported fuels. A complete dual-fuel (natural gas/diesel) conversion system developed using mostly commercially available components, for the Hino EC-100 diesel engine is described. Both diesel and natural gas operating modes are possible, without undermining normal engine performance as a diesel. The conversion system has performance similar to the ‘straight diesel’ operation, with comparable efficiency at full load. Furthermore, particulate and oxide of nitrogen (NOx) emissions are considerably lower than on diesel, however, carbon monoxide and hydrocarbon exhaust emissions are higher, particularly at light load.

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.

A phenomenological combustion analysis of a dual-fuel natural-gas diesel engine

2016 ◽  
Vol 231 (1) ◽  
pp. 66-83 ◽  
Author(s):  
Shuonan Xu ◽  
David Anderson ◽  
Mark Hoffman ◽  
Robert Prucka ◽  
Zoran Filipi
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Heat Release ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Dual Fuel ◽  
Injection Timing ◽  
Heavy Duty ◽  
Engine System ◽  
Wiebe Function

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.

Feasibility Analysis of Refuelling Infrastructure for Compressed Renewable Natural Gas Long-Haul Heavy-Duty Trucks in Canada

2021 ◽  
Author(s):  
Wahiba Yaïci ◽  
Michela Longo
Keyword(s):  
Natural Gas ◽  
Test Cases ◽  
Selling Price ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Transportation Sector ◽  
Depth Analysis ◽  
Harmful Emissions ◽  
Renewable Natural Gas ◽  
The Cost

Abstract With environmental concerns and limited natural resources, there is a need for cleaner sources of energy in the transportation sector. Renewable natural gas (RNG) is being considered as a potential fuel for heavy-duty applications due to its comparable usage to diesel and gasoline in vehicles. The idea of compressed RNG vehicles is being proposed especially because it will potentially significantly reduce harmful emissions into the environment. This initiative is taken in order to decrease vehicle emissions and support Canada’s commitments to the climate plans reinforcing active transportation infrastructure, in concert with new transit infrastructure, and zero emission vehicles. This study examines the feasibility of implementing a nationwide network of compressed RNG refuelling infrastructure in order to accommodate a conversion of Canada’s long-haul, heavy-duty truck fleet from diesel fuel to RNG. Two methods, Constant Traffic and Variable Traffic, along with data about compressed RNG infrastructure and vehicles, were developed and used to predict fuelling requirements for Canada’s long-haul, heavy-duty truck fleet. Then, a detailed economic analysis was conducted on various test cases to estimate how different variables impact the final selling price of RNG. This provided insight with the understanding of what factors go into pricing RNG and if it can compete against diesel in the trucking market. Results disclosed that the cost to purchase RNG is the greatest factor in the final selling price of compressed RNG. Due to the variability in RNG production however, there is no precise cost, which makes predictions difficult. However, results revealed that it is possible for compressed RNG to be competitive with diesel, with the mean compressed RNG price being 16.5% cheaper than diesel, before being taxed. Future studies should focus on the feasibility of the production of RNG and the associated costs, with emphasis on the Canadian landscape. An in-depth analysis on operational and maintenance costs for compressed RNG refuelling stations may also provide predictions that are more accurate.

scholarly journals Parametric Knocking Performance Investigation of Spark Ignition Natural Gas Engines and Dual Fuel Engines

2020 ◽  
Vol 8 (6) ◽  
pp. 459 ◽  
Author(s):  
La Xiang ◽  
Gerasimos Theotokatos ◽  
Haining Cui ◽  
Keda Xu ◽  
Hongkai Ben ◽  
...  
Keyword(s):  
Natural Gas ◽  
Compression Ratio ◽  
Engine Performance ◽  
Spark Ignition ◽  
Combustion Model ◽  
Dual Fuel ◽  
Ignition Timing ◽  
Natural Gas Engines ◽  
Study Results ◽  
Pilot Fuel

Both spark ignition (SI) natural gas engines and compression ignition (CI) dual fuel (DF) engines suffer from knocking when the unburnt mixture ignites spontaneously prior to the flame front arrival. In this study, a parametric investigation is performed on the knocking performance of these two engine types by using the GT-Power software. An SI natural gas engine and a DF engine are modelled by employing a two-zone zero-dimensional combustion model, which uses Wiebe function to determine the combustion rate and provides adequate prediction of the unburnt zone temperature, which is crucial for the knocking prediction. The developed models are validated against experimentally measured parameters and are subsequently used for performing parametric investigations. The derived results are analysed to quantify the effect of the compression ratio, air-fuel equivalence ratio and ignition timing on both engines as well as the effect of pilot fuel energy proportion on the DF engine. The results demonstrate that the compression ratio of the investigated SI and DF engines must be limited to 11 and 16.5, respectively, for avoiding knocking occurrence. The ignition timing for the SI and the DF engines must be controlled after −38°CA and 3°CA, respectively. A higher pilot fuel energy proportion between 5% and 15% results in increasing the knocking tendency and intensity for the DF Engine at high loads. This study results in better insights on the impacts of the investigated engine design and operating settings for natural gas (NG)-fuelled engines, thus it can provide useful support for obtaining the optimal settings targeting a desired combustion behaviour and engine performance while attenuating the knocking tendency.

ENGINE PERFORMANCE AND EXHAUST EMISSION OF DIESEL DUAL FUEL ENGINE FUELLED BY BIODIESEL, DIESEL AND NATURAL GAS

2016 ◽  
Vol 78 (6) ◽  
Author(s):  
Zulkifli Abdul Majid ◽  
Rahmat Mohsin ◽  
Abdul Hakim Shihnan
Keyword(s):  
Natural Gas ◽  
Nitrogen Oxide ◽  
Corn Oil ◽  
Methyl Esters ◽  
Direct Injection ◽  
Engine Performance ◽  
Poor Performance ◽  
Exhaust Emission ◽  
Dual Fuel ◽  
Engine Torque

The performance and exhaust emission of 6 cylinder four stroke direct injection diesel dual fuel (DDF) engine were investigated, the duel fuel used is corn oil methyl esters consist of 5%, 10%, 15% and 20% blends with diesel and compressed natural gas (CNG). Experiment was conducted at a fixed compression ratio of 17.5:1 with variance of engine speed 1400, 1800, 2400 and 2600 rpm. Combination of Biodiesel and CNG showed a better result on engine performance in terms of horse power and engine torque compared to other types of tested fuel. The substantial decrease of 25.6 % in exhaust emission flue was observed, giving lower value of UHC and nitrogen oxide (NOx). However, when the fuel is blended with CNG, a poor performance on exhaust emission was recorded, which include carbon dioxide (CO2), carbon monoxide (CO), unburned hydrocarbon (UHC) and nitrogen oxide (NOx) due to presence of CNG in fuel. 

Impact of pilot diesel ignition mode on combustion and emissions characteristics of a diesel/natural gas dual fuel heavy-duty engine

Fuel ◽  
2016 ◽  
Vol 167 ◽  
pp. 248-256 ◽  
Author(s):  
Zhongshu Wang ◽  
Zhongxiang Zhao ◽  
Dan Wang ◽  
Manzhi Tan ◽  
Yongqiang Han ◽  
...  
Keyword(s):  
Natural Gas ◽  
Dual Fuel ◽  
Heavy Duty

Combustion Characteristics of a Dual Fuel Diesel Engine With Natural Gas (Influence of Cetane Number of Ignition Fuel)

2011 ◽  
Author(s):  
Yasufumi Yoshimoto ◽  
Eiji Kinoshita
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Cetane Number ◽  
Engine Performance ◽  
Mean Value ◽  
Combustion Characteristics ◽  
Combustion Stability ◽  
Dual Fuel ◽  
Gas Oil ◽  
Performance And Emission

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.

Engine Performance and Emissions for a Heavy-Duty Diesel Engine Converted to Stoichiometric Natural Gas Operation

2020 ◽  
Author(s):  
Jinlong Liu ◽  
Christopher Ulishney ◽  
Cosmin E. Dumitrescu
Keyword(s):  
Natural Gas ◽  
Catalytic Converter ◽  
Combustion Process ◽  
Engine Performance ◽  
Intake Manifold ◽  
Heavy Duty ◽  
Indicated Mean Effective Pressure ◽  
Performance And Emissions ◽  
Heavy Duty Diesel ◽  
Ci Engines

Abstract Converting existing compression ignition (CI) engines to spark ignition (SI) operation can increase the use of natural gas (NG) in heavy-duty engine applications and reduce the reliance on petroleum fuels. Gas fumigation upstream of the intake manifold and the addition of a spark plug in place of the diesel injector to initiate and control the combustion process is a convenient approach for converting existing diesel engines to dedicated NG operation. Stoichiometric operation and a three-way catalytic converter can help the engine to comply with increasingly strict emission regulations. However, as the CI-to-SI conversion usually maintains the conventional geometry of a CI engine (i.e., maintains the flat cylinder head and the bowl-in piston), the goal of this study was to observe some of the effects that the diesel conversion to stoichiometric NG SI operation will have on the engine’s performance and emissions. Dynamometer tests were performed at a constant engine speed at 1300 rpm but various spark timings. The experimental results for a net indicated mean effective pressure ∼ 6.7 bar showed that ignition timing did not affect the end of combustion due to the slow-burn inside the squish. Moreover, the less-optimal conditions inside the squish led to increased carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions. While the combustion event was stable with no signs of knocking at the medium load conditions investigated here, the results suggest that the engine control needs to optimize the mass fraction trapped inside the squish region for a higher efficiency and lower emissions.

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