Mohamed Y. E. Selim

Sensitivity of dual fuel engine combustion and knocking limits to gaseous fuel composition

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking and ignition limits are presented as torque output at the onset of knocking and ignition failure. Experimental investigation on the dual fuel engine revealed the noise generated from combustion, knocking and ignition limits for all gases at different design and operating conditions. A Ricardo E6 Diesel version engine is converted to run on dual fuel of Diesel and the tested gaseous fuel and is used throughout the work. The engine is fully computerized, and the cylinder pressure data, crank angle data and engine operating variables are stored in a PC for off line analysis. The effects of engine speeds, loads, pilot injection angle, pilot fuel quantity and compression ratio on combustion noise, knocking torque, thermal efficiency and maximum pressure are examined for the dual engine running on the three gaseous fuels separately. The combustion noise, knocking and ignition limits are found to relate to the type of gaseous fuels and to the engine design and operating parameters. � 2003 Elsevier Ltd. All rights reserved.

Effect of exhaust gas recirculation on some combustion characteristics of dual fuel engine

Combustion pressure rise rate and thermal efficiency data are measured and presented for a dual fuel engine running on a dual fuel of Diesel and compressed natural gas and utilizing exhaust gas recirculation (EGR). The maximum pressure rise rate during combustion is presented as a measure of combustion noise. The experimental investigation on the dual fuel engine revealed the noise generated from combustion and the thermal efficiency at different EGR ratios. A Ricardo E6 Diesel version engine is converted to run on a dual fuel of Diesel and compressed natural gas and having an exhaust gas recycling system is used throughout the work. The engine is fully computerized, and the cylinder pressure data and crank angle data are stored in a PC for offline analysis. The effects of EGR ratio, engine speeds, loads, temperature of recycled exhaust gases, intake charge pressure and engine compression ratio on combustion noise and thermal efficiency are examined for the dual fuel engine. The combustion noise and thermal efficiency of the dual fuel engine are found to be affected when EGR is used in the dual fuel engine.

Combustion of jojoba methyl ester in an indirect injection diesel engine

An experimental investigation has been carried out to examine for the first time the performance and combustion noise of an indirect injection diesel engine running with new fuel derived from pure jojoba oil, jojoba methyl ester, and its blends with gas oil. A Ricardo E6 compression swirl diesel engine was fully instrumented for the measurement of combustion pressure and its rise rate and other operating parameters. Test parameters included the percentage of jojoba methyl ester in the blend, engine speed, load, injection timing and engine compression ratio. Results showed that the new fuel derived from jojoba is generally comparable and good replacement to gas oil in diesel engine at most engine operating conditions, in terms of performance parameters and combustion noise produced.

Effects of diesel/water emulsion on heat flow and thermal loading in a precombustion chamber diesel engine

An experimental investigation has been carried out to study the effects of using water/diesel emulsion fuel in an indirect injection diesel engine on the heat flux crossing liner and cylinder head, thermal loading and metal temperature distribution. A single cylinder precombustion chamber diesel engine has been used in the present work. The engine was instrumented for performance, metal temperature and heat flux measurements. The pure gas oil fuel and different ratios of water/diesel emulsion were used and their effects on the heat flux level and the injector tip temperature are studied. Two correlation were found for the heat flux crossing the liner and the cylinder head at various water/diesel emulsion ratios, fuelling rate and thermocouple probe locations. It was found that the addition of water to diesel fuel, to control the nitrogen oxides emissions, has great influence on reducing the heat flux, the metal temperatures and thermal loading of combustion chamber components.

Stability Behavior of Water-in-Diesel Fuel Emulsion

Abstract The presence of water within diesel fuel in the form of water-in-diesel (W/D) emulsion lowers the pollution level of nitrogen oxides and particulate matter. Emulsion of W/D was prepared by high-speed mixing and gradually adding water into the diesel fuel containing a small amount of emulsified agent. We measured the physical properties of diesel fuel and W/D emulsions with a pycnometer for density, Fann V.G. rotational viscometer (Chandler Engineering, Model 3500, Tulsa, Oklahoma, USA) for viscosity, and a Fisher Surface Tensiomat (Fisher Scientific Co., Model 21, Hampton, New Hampshire, USA) for surface tension. We used a computer image analyzer system to investigate the water droplet fuel interaction and the water droplet distribution within the diesel phase. The results of this study show that the emulsions of 10% and 20% W/D were stabilized for 4 weeks and 10 days, respectively, under the conditions of 0.2% surfactant, 15,000 rpm, and 2 minutes of mixing time. Under the same conditions, the stability period is limited to 5 hours for emulsions with a water concentration higher than 20%. An optimum surfactant concentration of 2% was found for 40% W/D due to the polydispersity behavior of the added surfactant. The water droplet distribution and average diameter were significantly affected by the total number of mixing revolutions. We measured and investigated the physical properties of the stable W/D emulsions in terms of density, surface tension, and viscosity.

Combustion Study of Stabilized Water-in-Diesel Fuel Emulsion

Abstract An experimental investigation has been carried out to produce a stable diesel/water emulsion fuel and use it in a diesel engine under different operating and design conditions. The emulsion stayed stable for up to 30% water in diesel for up to one week and 20% water in diesel for four weeks. The physical properties of the stable W/D emulsions in terms of density, surface tension, and viscosity were measured and investigated. The effect of surfactant concentration, mixing time, and mixer speed has been studied. A computer image analyzer system was used to investigate the water droplets-fuel interaction and the water droplets distribution within the diesel phase. The stable emulsion has been used in an indirect injection Ricardo E6 research diesel engine, and performance and engine roughness parameters have been measured. The effect of water/diesel ratio, engine speeds, loads, fuel injection angle, and engine compression ratio on combustion maximum pressure, maximum pressure rise rate, brake power output, and brake-specific fuel consumption has been studied. The addition of water in diesel generally affected the engine combustion noise, brake power output, and specific fuel consumption.

Utilization of extracted jojoba fruit as a fuel

Extracted jojoba solid waste has been used for almost the first time in this study as renewable solid fuel for furnaces. The extracted jojoba is derived from the fruit waste after extracting the oil from seeds. The jojoba remains are analysed and their physical and chemical features are reported. It is found that they contain much volatile combustible material which is expected to ease its combustion in furnaces. The performance of such solid fuels in a small-scale furnace with a fixed bed at its bottom has been investigated. The furnace considered has been equipped in some of the runs with baffles in an attempt to increase the residence time of combustible gases, and hence ensure better combustion and heat transfer performance. Different experimental runs with different air-to-fuel ratios (from 7:1 to 20.8:1 compared with the theoretical value of 9.7:1) have been tested. The results indicate a good feasibility of jojoba remains as a renewable fuel for furnaces. Theoretical modelling or extended experiments will be needed to further investigate the heat of combustion at other conditions.

A Study of Some Combustion Characterstics of Dual Fuel Engine Using EGR

An experimental investigation has been carried out to study the effects of using exhaust gas recirculation, EGR, on the combustion pressure rise rate and thermal efficiency of a dual fuel engine running on diesel and compressed natural gas. The maximum pressure rise rate during combustion is presented as a measure of combustion noise. Experimental data from the dual fuel engine with EGR has revealed the noise generated from combustion and thermal efficiency at different EGR ratios. A Ricardo E6 diesel engine was converted to run on dual fuel of diesel and compressed natural gas and an exhaust gas recycling system is used throughout the work. The engine was fully computerized and the cylinder pressure data, crank angle data are stored in a PC for off-line analysis. The effects of EGR ratio, engine speeds, loads, temperature of recycled exhaust gases, intake charge pressure, and engine compression ratio on combustion noise and thermal efficiency were examined for the dual fuel engine. The combustion noise and thermal efficiency of the dual fuel engine are found to be affected when the EGR was used in the dual fuel engine.

The Effect of Temperature and Mixing on the Density and Viscosity of Jojoba-diesel Fuels

The density and viscosity of several jojoba oil biodiesel–diesel fuel blends (B10, B20, B30, B50, and pure fuels B0 and B100) were measured for almost the first time according to the corresponding ASTM standards. In order to predict these properties, mixing rules are evaluated as a function of the volume fraction of biodiesel in the blend and also to check the validity of the mixing rules. The absolute percentage deviations obtained were low, demonstrating the suitability of the used mixing rules. The jojoba biodiesel and its blends have slightly higher density and viscosity, however, the kinematic viscosity may be lowered significantly by increasing the temperature of the fuel. The current work presented lacking data for the jojoba biodiesel and its blend with diesel. These data are required for further experimentation of the fuel, or for simulation and modeling purposes.

Combustion of waste chocolate oil biofuel in a diesel engine

An experimental study has been carried for almost first time to use methyl esters derived from waste chocolate oil produced from chocolate industry, in an indirect injection diesel engine. Effects of engine speed, engine load output, injection timing of the biofuel and the blend ratio with pure diesel fuel on the engine output torque, combustion noise (maximum pressure rise rate), maximum pressure and maximum heat release rate have been studied. Raw waste oil extracted from the industrial process to produce chocolate has been used to produce the biofuel and its physical and chemical properties have been measured and performance of diesel engine combustion has been evaluated in a Ricardo E6 research engine. It has been found that the biofuel (chocolate oil methyl ester) properties are almost similar to that of diesel and the engine performance was similar to diesel engine running on pure diesel fuel. There is no need to modify the engine when this biofuel is used.