Experimental investigations of a single cylinder four stroke diesel engine using modified piston bowl fuelled with Jojoba biodiesel blend

This paper represents the relative performance of a small single-cylinder diesel engine having capacity 3.5 kW. This paper covers experimental investigations of most influencing combustion parameters such as compression ratio, injection pressure and start of injection timing and their values on performance, emission and combustion characteristic of the small single-cylinder CRDI diesel engine for which the mechanical fuel injection system retrofitted with a simple version of the CRDI system. CRDI has yielded good results for large diesel and petrol engines but still not incorporate for cheaper small single-cylinder engines, typically used in the agricultural sector and decentralized power sector for a country like India. It is observed that starts of injection timing and injection pressure are the key parameters for improving the combustion characteristics and therefore engine performance while compression ratio mainly affects the emission characteristics of the engine. Retrofitted CRDI system yielded improved exhaust emission and performance of the engine.

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Effect of Combustion Chamber Geometry on Emissions From a Single-Cylinder Diesel Engine

ASME 2005 Internal Combustion Engine Division Fall Technical Conference (ICEF2005) ◽

10.1115/icef2005-1275 ◽

2005 ◽

Author(s):

Boggavarapu V. V. S. U. Prasad ◽

R. V. Ravikrishna

Keyword(s):

Diesel Engine ◽

Combustion Chamber ◽

Direct Injection ◽

Three Dimensional ◽

Cfd Simulations ◽

Government Regulations ◽

Single Cylinder ◽

Piston Bowl ◽

Computational Fluid Dynamics Cfd ◽

Valve Part

Many of the stationary power generation and agricultural pumping applications in India utilize diesel engines. Recently, as per Government regulations, these engines are required to satisfy stringent emissions norms. This forms the motivation for the present study on a stationary, direct-injection, single cylinder, 10 HP diesel engine. The selected engine was not satisfying the norms. The engine has a hemi- spherical piston bowl and an injector with a finite sac volume. The combustion chamber was made re-entrant and the injector was replaced with a sac-less injector. After these modifications, there is a significant change in emission levels. To understand clearly the effect of the combustion chamber geometry on the emission levels, three-dimensional computational fluid dynamics (CFD) simulations have been performed for the complete suction and closed-valve part of the cycle. Comparisons of turbulent kinetic energy and swirl levels of old and new geometries were systematically conducted. In contrary to the expected, that the swirl and turbulence levels are consistently less in the modified geometry than that of original geometry. A third combustion chamber was proposed and tested computationally. It was found that the in the proposed combustion chamber swirl and turbulence levels are much higher than the baseline engine. Thus, the proposed combustion chamber geometry shows significant potential for the engine to meet the prescribed norms.

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Piston Bowl Optimization for Single Cylinder Diesel Engine Using CFD

10.4271/2016-28-0107 ◽

2016 ◽

Cited By ~ 7

Author(s):

Saravanan Subramanian ◽

Balamurugan Rathinam ◽

J Isaac JoshuaRamesh Lalvani ◽

Kandaswamy Annamalai

Keyword(s):

Diesel Engine ◽

Single Cylinder ◽

Piston Bowl

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Comparison of Soot Evolution Using High-Speed CMOS Color Camera and Two-Color Thermometry in an Optical Diesel Engine Fueled With B20 Biodiesel Blend and Ultra-Low Sulfur Diesel

ASME 2011 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2011-60146 ◽

2011 ◽

Cited By ~ 4

Author(s):

Kan Zha ◽

Radu-Catalin Florea ◽

Marcis Jansons

Keyword(s):

Diesel Engine ◽

High Speed ◽

Soot Formation ◽

Soot Temperature ◽

Piston Bowl ◽

Ultra Low Sulfur Diesel ◽

Wall Impingement ◽

Kl Factor ◽

Biodiesel Blend ◽

Low Sulfur

Biodiesel is a desirable alternative fuel for the diesel engine due to its low engine-out soot emission tendency. When blended with petroleum-based diesel fuels, soot emissions generally decrease in proportion to the volume fraction of biodiesel in the mixture. While comparisons of engine-out soot measurements between biodiesel blends and petroleum-based diesel have been widely reported, in-cylinder soot evolution has not been experimentally explored to the same extent. To elucidate the soot emission reduction mechanism of biodiesel, a single-cylinder optically-accessible diesel engine was used to compare the in-cylinder soot evolution when fueled with ultra-low sulfur diesel (ULSD) to that using a B20 biodiesel blend (20% vol/vol biodiesel ASTM D6751-03A). Soot temperature and KL factors are simultaneously determined using a novel two-color optical thermometry technique implemented with a high-speed CMOS color camera having wide-band Bayer filters. The crank-angle resolved data allows quantitative comparison of the rate of in-cylinder soot formation. High-speed spray images show that B20 has more splashing during spray wall impingement than ULSD, distributing rebounding fuel droplets over a thicker annular ring interior to the piston bowl periphery. The subsequent soot luminescence is observed by high-speed combustion imaging and soot temperature and KL factor measurements. B20 forms soot both at low KL magnitudes over large areas between fuel jets, and at high values among remnants of the fuel spray, along its axis and away from the bowl edge. In contrast, ULSD soot luminescence is observed exclusively as pool burning on the piston bowl surfaces resulting from fuel wall impingement. The soot KL factor evolution during B20 combustion indicates earlier and significantly greater soot formation than with ULSD. B20 combustion is also observed to have a greater soot oxidation rate which results in lower engine-out soot emissions. Measured soot temperatures near 1875K were similar for the two fuels for the duration of combustion. For both fuels, higher fuel injection pressure led to lower late-cycle soot KL levels. The trends of soot natural luminosity correlated well with the trends of soot KL factor, suggesting that relatively simple measurements of combustion luminosity may provide somewhat quantitative information about in-cylinder soot formation and oxidation. The apparent rate of heat release (ARHR) analysis under steady skip-fire conditions indicates that B20 combustion is less sensitive to wall temperature than that observed with ULSD due to a lesser degree of pool burning. B20 was found to have both a shorter ignition delay and shorter combustion duration than ULSD.

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