Analysis of mixed premixed combustion characteristics of biodiesel candlenut oil (Aleurites Moluccana) with biodiesel fuel

The aim of this work is to investigate the effect of the blending ratio and pilot injection on the spray and combustion characteristics of biodiesel fuel and compare these factors with those of diesel fuel in a direct injection common-rail diesel engine. In order to study the factors influencing the spray and combustion characteristics of biodiesel fuel, experiments involving exhaust emissions and engine performance were conducted at various biodiesel blending ratios and injection conditions for engine operating conditions. The macroscopic and microscopic spray characteristics of biodiesel fuel, such as injection rate, split injection effect, spray tip penetration, droplet diameter, and axial velocity distribution, were compared with the results from conventional diesel fuel. For biodiesel blended fuel, it was revealed that a higher injection pressure is needed to achieve the same injection rate at a higher blending ratio. The spray tip penetration of biodiesel fuel was similar to that of diesel. The atomization characteristics of biodiesel show that it has higher Sauter mean diameter and lower spray velocity than conventional diesel fuel due to high viscosity and surface tension. The peak combustion pressures of diesel and blending fuel increased with advanced injection timing and the combustion pressure of biodiesel fuel is higher than that of diesel fuel. As the pilot injection timing is retarded to 15deg of BTDC that is closed by the top dead center, the dissimilarities of diesel and blending fuels combustion pressure are reduced. It was found that the pilot injection enhanced the deteriorated spray and combustion characteristics of biodiesel fuel caused by different physical properties of the fuel.

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Fundamental Study of Spray and Partially Premixed Combustion of Methane/Air Mixture

Journal of Energy Resources Technology ◽

10.1115/1.4007911 ◽

2012 ◽

Vol 135 (2) ◽

Cited By ~ 32

Author(s):

Omid Askari ◽

Hameed Metghalchi ◽

Siamak Kazemzadeh Hannani ◽

Ali Moghaddas ◽

Reza Ebrahimi ◽

...

Keyword(s):

Direct Injection ◽

Cone Angle ◽

Combustion Characteristics ◽

Constant Volume ◽

Premixed Combustion ◽

Chamber Pressure ◽

Spray Cone ◽

Partially Premixed Combustion ◽

Homogeneous Combustion ◽

Partially Premixed

This study presents fundamentals of spray and partially premixed combustion characteristics of directly injected methane in a constant volume combustion chamber (CVCC). The constant volume vessel is a cylinder with inside diameter of 135 mm and inside height of 135 mm. Two end of the vessel are equipped with optical windows. A high speed complementary metal oxide semiconductor (CMOS) camera capable of capturing pictures up to 40,000 frames per second is used to observe flow conditions inside the chamber. The injected fuel jet generates turbulence in the vessel and forms a turbulent heterogeneous fuel–air mixture in the vessel, similar to that in a compressed natural gas (CNG) direct-injection (DI) engine. The fuel–air mixture is ignited by centrally located electrodes at a given spark delay timing of 1, 40, 75, and 110 ms. In addition to the four delay times, a 5 min waiting period was used in order to make sure of having laminar homogeneous combustion. Spray development and characterization including spray tip penetration (STP), spray cone angle (SCA), and overall equivalence ratio were investigated under 30–90 bar fuel pressures and 1–5 bar chamber pressure. Flame propagation images and combustion characteristics were determined via pressure-derived parameters and analyzed at a fuel pressure of 90 bar and a chamber pressure of 1 bar at different stratification ratios (S.R.) (from 0% to 100%) at overall equivalence ratios of 0.6, 0.8, and 1.0. Shorter combustion duration and higher combustion pressure were observed in direct injection-type combustion at all fuel air equivalence ratios compared to those of homogeneous combustion.

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Hydrogen/oxygen premixed combustion characteristics in micro porous media combustor

Applied Energy ◽

10.1016/j.apenergy.2014.12.049 ◽

2015 ◽

Vol 160 ◽

pp. 802-807 ◽

Cited By ~ 81

Author(s):

J.F. Pan ◽

D. Wu ◽

Y.X. Liu ◽

H.F. Zhang ◽

A.K. Tang ◽

...

Keyword(s):

Porous Media ◽

Combustion Characteristics ◽

Premixed Combustion

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Investigation on the Impact of Fuel Properties on Partially Premixed Combustion Characteristics in a Light Duty Diesel Engine

ASME 2012 Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/ices2012-81184 ◽

2012 ◽

Cited By ~ 7

Author(s):

Hadeel Solaka ◽

Martin Tunér ◽

Bengt Johansson

Keyword(s):

Pressure Rise ◽

Combustion Characteristics ◽

Premixed Combustion ◽

Unburned Hydrocarbon ◽

Light Duty ◽

Start Of Injection ◽

Partially Premixed Combustion ◽

Rise Rate ◽

Partially Premixed ◽

The Impact

The impact of fuel composition on the emission performance and combustion characteristics for partially premixed combustion (PPC) were examined for four fuels in the gasoline boiling range together with Swedish diesel MK1. Experiments were carried out at 8 bar IMEPg and 1500 rpm with 53±1% EGR and λ = 1.5. This relation gave inlet mole fractions of approximately 5% CO2 and 13% O2. The combustion phasing was adjusted by means of start of injection (SOI), for all fuels, over the range with stable combustion and acceptable pressure rise rate combined with maintained λ, EGR ratio, inlet pressure, and load. The operating range was limited by combustion instability for the high RON fuels, while MK1 and the low RON fuels could be operated over the whole MBT plateau. The largest difference in engine-out emissions between the fuels was the filtered smoke number (FSN), as the gasoline fuels produced a much lower FSN value than MK1. Higher RON value gave higher levels of carbon monoxide (CO) and unburned hydrocarbon (HC) for the gasoline fuels, while MK1 had the lowest levels of these emissions.

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