Publications Internationales
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Item Investigation of natural gas enrichment with high hydrogen participation in dual fuel diesel engine(Elsevier, 2021) Benbellil, Messaoud Abdelalli; Lounici, Mohand Said; Loubar, Khaled; Tazerout, MohandThis study explores the impact of natural gas (NG) enrichment with high H2 concentrations (20, 30, 40 and 50 by v %) on combustion characteristics, engine performance, exhaust emissions and knock in a compression ignition engine running in dual fuel (DF) mode. Results indicated that H2 addition to NG contributes to enhance gaseous fuel combustion that corresponds to an increased heat release rate (HRR) during the premixed phase of gaseous fuel that also causes an increase in the pressure peak, particularly at high loads. The maximum pressure peak and HRR correspond to 50% H2 addition. The combustion duration is shortened for all H2 mixtures. Regarding engine performance, an important benefit in terms of brake thermal efficiency is noted for all H2 blends; it increases with increasing enrichment rate and reaches approximately 16% increase for the 50% H2 mixture relative to pure NG case. Moreover, enriching NG with H2 is an effective solution for reducing unburned hydrocarbons and carbon monoxide at moderate to high engine loads. However, for NOx emissions, the addition of H2 to NG is only attractive at low and moderate loads. In addition, over 80% engine load, NG enrichment with H2 generates knock, which rapidly reaches high intensities.Item Knock characterization and development of a new knock indicator for dual-fuel engines(Elsevier, 2017) Lounici, Mohand Said; Benbellil, Messaoud Abdelalli; Loubar, K.; Niculescu, D.C.; Tazerout, MohandDual-fuel mode is a promising technique for natural gas utilization in internal combustion engines. However, for high loads operation, the engine risks to go through a hazardous knocking regime. Knock phenomenon is an abnormal combustion that can cause some disagreeable effects in engines where it occurs. It can even induce brutal irreparable engine damage under severe knocking conditions. The present paper aims first to highlight and characterize knock in dual-fuel engines fueled with natural gas as main fuel and diesel as pilot fuel. Description of this phenomenon is investigated in this type of engines. Knock behavior in dual-fuel engine is compared to spark ignition engine case. Cyclical variability of this phenomenon is studied. A new knock indicator, based on in-cylinder pressure analysis, is proposed in order to identify and evaluate knock in dual-fuel engines. In addition, knock effects on heat release, cylinder wall temperature and engine performance and emissions are examined. New techniques to delay knock appearance in this type of engines are investigated. It is found that the increase in pilot fuel quantity is an effective technique to delay knock onset in NG dual-fuel enginesItem Uncertainty study of fiscal orifice meter used in a gas Algerian field(Elsevier, 2019) Bekraoui, Amina; Hadjadj, Ahmed; Benmounah, Abdelbaki; Oulhadj, MohammedUncertainty variation of a fiscal orifice measurement system used in an Algerian natural gas exportation station is studied using data from a natural gas production field known as Gas Tin Fouye Tabankort (GTFT) located in the south-east of Algeria. The expected results are uncertainty calculus over a range of temperature and pressure variation and to the customs authorities’ allocation. In fact, each quantity of measured fluid flow has certain uncertainty and then the fiscal measurement station is very important for gas exportation, which means the income. Therefore, the pursuit of flow metering device uncertainty and its influence on the measured quantities in the transmission networks is very important. For that, the uncertainty caused by flowmeter in the measurement station causing economical revenue fluctuations is studied. The work was done to justify why there is a production decrease of hydrocarbons without identifying reasons during summer. The difference between the mass flow rate quantity produced and the transmitted value was important that is why our work is done to clarify exactly from where the problem can come. The measurements setting with two operating conditions (gas temperature and pressure) show that the uncertainty is dominated by seasonal temperatures and pressures variations which induce fluctuation in gas and pipe temperatures and influence the metrological performance of the transmitters. Indeed, the metrological measurement chain performance is affected also by these two operating conditions. The present work is done according to the ONML (National Legal Metrological Office) instructions regarding differences between the measured and the seller values represented by the mass flow rate. In natural gas transmission network, the important problem in the management and control of the network is represented by the unaccounted for gas, a quantity of measuring error which is to be considered in the equation of network balancing. One of the unaccounted for gas sources are the environmental conditions and systematic measurement errors. In this work, the calculation of the combined uncertainty of the mass flow rate measured by an Orifice fiscal gas metering plant is done. From the results founded, the authors confirm that the uncertainty in the measurement system causing by the climatic conditions generates unaccounted for gasItem Effect of natural gas enrichment with hydrogen on combustion characteristics of a dual fuel diesel engine(Elsevier, 2019) Ouchikh, Sarah; Lounici, Mohand Said; Tarabet, Lyes; Loubar, K.; Tazerout, MohandItem Hydrogen supplemented natural gas effect on a DI diesel engine operating under dual fuel mode with a biodiesel pilot fuel(Elsevier, 2017) Tarabet, L.; Lounici, M. S.; Loubar, K.; Khiari, K.; Bouguessa, R.; Tazerout, M.Item Experimental investigation on NG dual fuel engine improvement by hydrogen enrichment(Elsevier, 2014) Lounici, Mohand Said; Boussadi, Asma; Loubar, Khaled; Tazerout, MohandItem Towards improvement of natural gas-diesel dual fuel mode : an experimental investigation on performance and exhaust emissions(Elsevier, 2014) Lounici, Mohand Said; Loubar, Khaled; Tarabet, Lyes; Balistrou, Mourad; Niculescu, Dan-Catalin; Tazerout, MohandItem Experimental investigation of DI diesel engine operating with eucalyptus biodiesel/natural gas under dual fuel mode(Elsevier, 2014) Tarabet, L.; Loubar, K.; Lounici, M.S.; Khiari, K.; Belmrabet, T.; Tazerout, M.Item Investigation on heat transfer evaluation for a more efficient two-zone combustion model in the case of natural gas SI engines(Elsevier, 2011) Lounici, Mohand Said; Loubar, Khaled; Balistrou, Mourad; Tazerout, MohandTwo-zone model is one of the most interesting engine simulation tools, especially for SI engines. However, the pertinence of the simulation depends on the accuracy of the heat transfer model. In fact, an important part of the fuel energy is transformed to heat loss from the chamber walls. Also, knock appearance is closely related to heat exchange. However, in the previous studies using two-zone models, many choices are made for heat transfer evaluation and no choice influence study has been carried out, in the literature. The current study aims to investigate the effect of the choice of both the heat transfer correlation and burned zone heat transfer area calculation method and provide an optimized choice for a more efficient two-zone thermodynamic model, in the case of natural gas SI engines. For this purpose, a computer simulation is developed. Experimental measurements are carried out for comparison and validation. The effect of correlation choice has been first studied. The most known correlations have been tested and compared. Our experimental pressure results, supported for more general and reliable conclusions, by a literature survey of many other studies, based on measured heat transfer rates for several SI engines, are used for correlation selection. It is found that Hohenberg’s correlation is the best choice. However, the influence of the burned zone heat transfer area calculation method is negligible