scholarly journals Zero-dimensional 2-phase combustion model in a dual-fuel compression ignition engine fed with gaseous fuel and a divided diesel fuel charge

2015 ◽  
Vol 17 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Maciej Mikulski ◽  
Slawomir Wierzbicki ◽  
Andrzej Pietak
Keyword(s):  
Diesel Fuel ◽  
Gaseous Fuel ◽  
Combustion Model ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Fuel Charge

scholarly journals A Multicomponent Blend as a Diesel Fuel Surrogate for Compression Ignition Engine Applications

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Yuanjiang Pei ◽  
Marco Mehl ◽  
Wei Liu ◽  
Tianfeng Lu ◽  
William J. Pitz ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Flow Reactor ◽  
Expert Knowledge ◽  
Combustion Model ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Combined Mechanism ◽  
Fuel Surrogate ◽  
Skeletal Mechanism

A mixture of n-dodecane and m-xylene is investigated as a diesel fuel surrogate for compression ignition (CI) engine applications. Compared to neat n-dodecane, this binary mixture is more representative of diesel fuel because it contains an alkyl-benzene which represents an important chemical class present in diesel fuels. A detailed multicomponent mechanism for n-dodecane and m-xylene was developed by combining a previously developed n-dodecane mechanism with a recently developed mechanism for xylenes. The xylene mechanism is shown to reproduce experimental ignition data from a rapid compression machine (RCM) and shock tube (ST), speciation data from the jet stirred reactor and flame speed data. This combined mechanism was validated by comparing predictions from the model with experimental data for ignition in STs and for reactivity in a flow reactor. The combined mechanism, consisting of 2885 species and 11,754 reactions, was reduced to a skeletal mechanism consisting 163 species and 887 reactions for 3D diesel engine simulations. The mechanism reduction was performed using directed relation graph (DRG) with expert knowledge (DRG-X) and DRG-aided sensitivity analysis (DRGASA) at a fixed fuel composition of 77% of n-dodecane and 23% m-xylene by volume. The sample space for the reduction covered pressure of 1–80 bar, equivalence ratio of 0.5–2.0, and initial temperature of 700–1600 K for ignition. The skeletal mechanism was compared with the detailed mechanism for ignition and flow reactor predictions. Finally, the skeletal mechanism was validated against a spray flame dataset under diesel engine conditions documented on the engine combustion network (ECN) website. These multidimensional simulations were performed using a representative interactive flame (RIF) turbulent combustion model. Encouraging results were obtained compared to the experiments with regard to the predictions of ignition delay and lift-off length at different ambient temperatures.

scholarly journals Effect of CO2 content in CNG on the combustion process in a dual-fuel compression ignition engine

2015 ◽  
Vol 162 (3) ◽  
pp. 91-101
Author(s):  
Sławomir WIERZBICKI ◽  
Maciej MIKULSKI ◽  
Michał ŚMIEJA
Keyword(s):  
Combustion Process ◽  
Gaseous Fuel ◽  
Dual Fuel ◽  
Combustion Engines ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Toxic Compounds ◽  
Alternative Sources ◽  
Effective Use ◽  
And Control

Seeking alternative sources of energy for its more effective use, reducing emissions of toxic pollutants to the atmosphere and counteracting global warming are nowadays the major areas of development in the power industry, including the design of combustion engines. Currently, the research into the use of new fuels, which may be effective sources of energy, is performed by many scientific centres. The use of biogas for production of energy in cogeneration systems is one of the ways for improvement of energy balance. In the research described herein, a dual-fuel compression ignition engine was fuelled with gaseous fuel with variable CNG and CO2 ratios. The tests were performed for engine fuelling controlled by both an original controller with the software optimised for single-fuel operation and for the injection of a pilot dose of diesel controlled by a dedicated controller enabling the adjustment and control of the injection and dose parameters. This paper presents the effect of carbon dioxide content in gaseous fuel on the combustion process and emission of toxic compounds in the engine examined.

Cylinder Specific Pressure Predictions for Advanced Dual Fuel Compression Ignition Engines Utilizing a Two-Stage Functional Data Analysis

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xiao Huang ◽  
Lulu Kang ◽  
Mateos Kassa ◽  
Carrie Hall
Keyword(s):  
Combustion Process ◽  
Operating Parameter ◽  
Combustion Model ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Specific Pressure ◽  
Compression Ignition Engine ◽  
Two Stage ◽  
Pressure Trace

In-cylinder pressure is a critical metric that is used to characterize the combustion process of engines. While this variable is measured on many laboratory test beds, in-cylinder pressure transducers are not common on production engines. As such, accurate methods of predicting the cylinder pressure have been developed both for modeling and control efforts. This work examines a cylinder-specific pressure model for a dual fuel compression ignition engine. This model links the key engine input variables to the critical engine outputs including indicated mean effective pressure (IMEP) and peak pressure. To identify the specific impact of each operating parameter on the pressure trace, a surrogate model was produced based on a functional Gaussian process (GP) regression approach. The pressure trace is modeled as a function of the operating parameters, and a two-stage estimation procedure is introduced to overcome various computational challenges. This modeling method is compared to a commercial dual fuel combustion model and shown to be more accurate and less computationally intensive.

Knock Prediction in Industrial Dual Fuel Engines Using a Two-Zone Combustion Model With Consideration of Chemical Kinetics

2008 ◽  
Author(s):  
Ahmed Al-Sened ◽  
Hesameddin Safari ◽  
Mojtaba Keshavarz ◽  
Ghasem Javadirad
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Chemical Reactivity ◽  
Gaseous Fuel ◽  
Combustion Model ◽  
Dual Fuel ◽  
Injection Timing ◽  
Boost Pressure ◽  
Fuel Mass ◽  
Dual Fuel Engines

Knock is well recognized as a destructive phenomenon to be avoided when running dual fuel engines. Typically, it occurs at high loads and high ambient temperatures and its onset has always been difficult to predict, particularly where multiple fuels are present. In a dual fuel engine, knock can occur from either the diesel or the gaseous fuel and it is recognised that the ratio of diesel fuel mass to gaseous fuel mass is an important index in determining which type of knock is predominant. This paper describes the development of a two-zone predictive model for the onset of knock in a dual fuel engine. Prediction of spark knock onset is the main objective of present work. A 9-step short mechanism with 11 chemical species, developed specifically for modelling dual fuel operation, is used to determine the chemical reactivity of the end-gas zone. The contribution of pilot diesel fuel combustion is taken into account by a heat release model. Chemical equilibrium is assumed for the burned gas zone. Simulation results predict the point of knock-limited BMEP and its dependency on operating parameters such as air intake temperature, boost pressure, start of pilot fuel injection timing and compression ratio. The results were first validated against some published engine analysis data and also some in-house performance prediction data. Secondly, a known dual-fuel development engine was simulated. Finally, the performance of an engine which had been converted from diesel to dual fuel during its service life was modeled but commercial constraints prevent the identification of this engine within this paper. However, good agreement with existing performance data was demonstrated in all these cases.

Effect of Load Level on the Performance of a Dual Fuel Compression Ignition Engine Operating on Syngas Fuels With Varying H2/CO Content

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
B. B. Sahoo ◽  
U. K. Saha ◽  
N. Sahoo
Keyword(s):  
Diesel Engine ◽  
Thermal Efficiency ◽  
Peak Pressure ◽  
Gaseous Fuel ◽  
Dual Fuel ◽  
Engine Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Operation ◽  
Brake Thermal Efficiency

Syngas, an environmentally friendly alternative gaseous fuel for internal combustion engine operation, mainly consists of carbon monoxide (CO) and hydrogen (H2). It can substitute fossil diesel oil in a compression ignition diesel engine through dual fuel operation route. In the present investigation, experiments were conducted in a constant speed single cylinder direct injection diesel engine fuelled with syngas-diesel in a dual fuel operation mode. The main contribution of this study is to introduce the new synthetic gaseous fuel (syngas) including the possible use of CO gas, an alternative diesel engine fuel. In this work, four different H2 and CO compositions of syngas were chosen for dual fuel study under different engine loading levels. Keeping the same power output at the corresponding tested loads, the engine performance of dual fuel operations were compared to that of diesel mode for the entire load range. The maximum diesel replacement in the engine was found to be 72.3% for 100% H2 fuel. This amount replacement rate was reduced for the low energetic lower H2 content fuels. The brake thermal efficiency was always found highest (about 21%) in the case of diesel mode operation. However, the 100% H2 syngas showed a comparative performance level with diesel mode at the expense of higher NOx emissions. At 80% engine load, the brake thermal efficiency was found to be 15.7% for 100% CO syngas. This value increased to 16.1%, 18.3% and 19.8% when the 100% CO syngas composition was replaced by H2 contents of 50%, 75% and 100%, respectively. At part loads (i.e., at 20% and 40%), dual fuel mode resulted a poor performance including higher emission levels. In contrast, at higher loads, syngas fuels showed a good competitive performance to diesel mode. At all the tested loads, the NOx emission was observed highest for 100% H2 syngas as compared to other fuel conditions, and a maximum of 240 ppm was found at 100% load. However, when the CO fractions of 25%, 50% and 100%, were substituted to hydrogen fuel, the emission levels got reduced to 175 ppm, 127 ppm, and 114 ppm, respectively. Further, higher CO and HC emission levels were recorded for 25%, 50%, and 100% CO fraction syngas fuels due to their CO content. Ignition delay was found to increase for the dual fuel operation as compared to diesel mode, and also it seemed to be still longer for higher H2 content syngas fuels. The peak pressure and maximum rate of pressure rise were found to decrease for all the cases of dual fuel operation, except for 100% H2 syngas (beyond 60% load). The reduction in peak pressure resulted a rise in the exhaust gas temperature at all loads under dual fuel operation. The present investigation provides some useful experimental data which can be applied to the possible existing engine parameters modifications to produce a competitive syngas dual fuel performance at all the loading operations.

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