Exploration of Heat Release in a Homogeneous Charge Compression Ignition Engine with Primary Reference Fuels

2013 ◽  
Author(s):  
David Vuilleumier ◽  
Hatem Selim ◽  
Robert Dibble ◽  
Mani Sarathy
Keyword(s):  
Heat Release ◽  
Homogeneous Charge Compression Ignition ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Primary Reference ◽  
Primary Reference Fuels ◽  
Homogeneous Charge

Combustion and emission characteristics of a homogeneous charge compression ignition engine

2005 ◽  
Vol 219 (9) ◽  
pp. 1133-1139 ◽  
Author(s):  
Hu Tiegang ◽  
Liu Shenghua ◽  
Zhou Longbao ◽  
Zhu Chi
Keyword(s):  
Heat Release ◽  
Homogeneous Charge Compression Ignition ◽  
Cetane Number ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Hcci Engine ◽  
Homogeneous Charge

Dimethyl ether (DME) is a kind of fuel with high cetane number and low evaporating temperature, which is suitable for a homogeneous charge compression ignition (HCCI) engine. The combustion and emission characteristics of an HCCI engine fuelled with DME were investigated on a modified single-cylinder engine. The experimental results indicate that the HCCI engine combustion is a two-stage heat release process. The engine load or air-fuel ratio has significant effects on the maximum cylinder pressure and its position, the shape of the pressure rise rate and the heat release rate. The engine speed has little effect. A DME HCCI engine is smoke free, with zero NOx and low hydrocarbon and CO emissions under the operating conditions of 0.25–0.30 MPa brake mean effective pressure.

Uncertainty quantification from raw measurements to post-processed data: A general methodology and its application to a homogeneous-charge compression–ignition engine

2019 ◽  
Vol 21 (9) ◽  
pp. 1709-1737 ◽  
Author(s):  
Maxime Pochet ◽  
Hervé Jeanmart ◽  
Francesco Contino
Keyword(s):  
Heat Release ◽  
Uncertainty Quantification ◽  
Internal Combustion Engines ◽  
Homogeneous Charge Compression Ignition ◽  
Uncertainty Propagation ◽  
Compression Ignition ◽  
Post Processing ◽  
Compression Ignition Engine ◽  
Physical Quantities ◽  
Homogeneous Charge

Internal combustion engines have been improved for many decades. Yet, complex phenomena are now resorted to, for which any optimum might be unstable: noise, low-temperature heat release timing, stratification, pollutant sweet spots, and so on. In order to make reliable statements on an improvement, one must specify the uncertainty related to it. Still, uncertainty quantification is generally missing in the piston engine experimental literature. Therefore, we detailed a mathematical methodology to obtain any engine parameter uncertainty and then used it to derive the uncertainty expressions of the physical quantities of the most generic homogeneous-charge compression–ignition research engine (mass-flow-induced mixture with [Formula: see text] fuel). We then applied those expressions on an existing hydrogen homogeneous-charge compression–ignition test bench. This includes the uncertainty propagation chain from sensor specifications, user calibrations, intake control, in-cylinder processes, and post-processing techniques. Directly measured physical quantities have uncertainties of around 1%, depending on the sensor quality (e.g. pressure, volume), but indirectly measured quantities relying on modelled parameters have uncertainties higher than 5% (e.g. wall heat losses, in-cylinder temperature, gross heat release, pressure rise rate). Other findings that such an analysis can bring relate, for example, to the physical quantities driving the uncertainty and to the ones that can be neglected. In the case of the homogeneous-charge compression–ignition engine considered, the effects of blow-by, bottle purity and air moisture content were found negligible; the post-processing for effective compression ratio, effective in-cylinder temperature, and top dead centre offset were found essential; and the pressure and volume uncertainties were found to be the main drivers to a large extent. The obtained numeric values serve the general purpose of alerting the experimenter on uncertainty order of magnitudes. The developed methodology shall be used and adapted by the experimenter willing to study the uncertainty propagation in their setup or willing to assess the adequacy of a sensor performance.

Numerical study of the combustion mechanism of a homogeneous charge compression ignition engine fuelled with dimethyl ether and methane, with a detailed kinetics model

2005 ◽  
Vol 219 (10) ◽  
pp. 1213-1223 ◽  
Author(s):  
M Yao ◽  
J Qin ◽  
Z Zheng
Keyword(s):  
Heat Release ◽  
Dimethyl Ether ◽  
Homogeneous Charge Compression Ignition ◽  
Numerical Study ◽  
Kinetics Model ◽  
Compression Ignition ◽  
Temperature Reaction ◽  
Compression Ignition Engine ◽  
Auto Ignition ◽  
Homogeneous Charge

The auto-ignition and combustion mechanisms of dimethyl ether (DME) in a fourstroke homogeneous charge compression ignition (HCCI) engine were investigated using a zero-dimensional thermodynamic model coupled with a detailed chemical kinetics model. The results indicate that DME displays two-stage auto-ignition, and heat release with a low-temperature reaction and a high-temperature reaction (HTR). Heat release with the HTR can be separated into two stages: blue flame and hot flame. HCCI ignition is controlled by hydrogen peroxide (H2O2) decomposition, and OH plays a very important role in HCCI combustion. Formaldehyde (CH2O) is the main source of H2O2. Based on the sensitivity analysis of chemical reactions, the major paths of the DME reaction occurring in the engine cylinder are clarified. The major paths of the DME reaction is H-atom abstraction from DME, followed by the first addition of O2 and second addition of O2, and then oxidation to formaldehyde (CH2O), the formyl radical (HCO), and finally carbon monoxide (CO). CO oxidation occurs at the hot flame by the elementary reaction CO + OH = CO2 + H. At leaner DME concentrations, CO cannot be completely converted to carbon dioxide (CO2), and the process will result in high CO emissions.

Numerical study of the combustion mechanism of a homogeneous charge compression ignition engine fuelled with dimethyl ether and methane, with a detailed kinetics model. Part 2: the reaction kinetics of dimethyl ether and methane dual-fuel

2005 ◽  
Vol 219 (10) ◽  
pp. 1225-1236 ◽  
Author(s):  
M Yao ◽  
J Qin ◽  
Z Zheng
Keyword(s):  
Heat Release ◽  
Methane Oxidation ◽  
Dimethyl Ether ◽  
Homogeneous Charge Compression Ignition ◽  
Numerical Study ◽  
Kinetics Model ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Homogeneous Charge

A numerical study was carried out using a zero-dimensional detailed chemical kinetics model to investigate the chemical reaction phenomena encountered in the homogeneous charge compression ignition process of a dimethyl ether (DME) and methane dual-fuel mixture. The results show that the heat release of DME/methane dual-fuel combustion is a typical two-stage process: the first stage is mainly associated with DME oxidation, and the second is mainly the result of methane oxidation. The low-temperature reaction (LTR) of DME is inhibited, the second molecular oxygen addition of DME is restrained, and β-scission plays a dominant role in DME oxidation. Therefore, methane changes the paths of the LTR of DME. Most of the formaldehyde (CH2O) is produced from H abstraction of methoxy (CH3O) rather than from the LTR of the DME. The heat release by DME oxidation and the existence of H2O2 generated by DME oxidation make methane oxidation occur at a low initial temperature. However, methane oxidation also promotes hot flame reactions of DME. During the second stage of heat release, OH is produced in many different ways rather than only by way of H2O2 decomposing in neat DME oxidation; this results in higher OH mole fraction when dual fuel is used compared with DME alone. Finally, the major paths of the DME/methane HCCI reactions occurring in the engine cylinder are clarified.

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