Experimental study on the combustion characteristics of emulsified diesel in a rapid compression and expansion machine

Abstract

The combustion characteristics of emulsified diesel fuels are investigated in a rapid compression and expansion machine (RCEM). Among the test cases, the 40 water-oil (W/O) fuel injected at 20° before top dead center (BTDC) has shown the best performance with respect to efficiency and NO_x and soot emissions. The pressure trace of the 40 W/O fuel is characterized by a longer ignition delay and a lower rate of pressure rise in premixed combustion. High-speed photographs show reduced flame luminosity and lower flame temperature with increasing W/O ratio. Microexplosions of emulsified fuel droplets, which affect the local shape and brightness of the flame, are identified in magnified flame images.

Keywords

emulsified diesel rapid compression and expansion machine (RCEM)high-speed photographs microexplosions

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References

Tsukahara

Yoshimoto

W/O emulsion realizes low smoke and efficient operation of DI engines without high pressure injection. SAE paper 890449, 1989.

Tsukahara

Yoshimoto

Reduction of NO_x, smoke, BSFC, and maximum combustion pressure by low compression ratios in a diesel engine fuelled by emulsified fuel. SAE paper 920464, 1992.

Kohketsu

Mori

Sakai

Nakagawa

Reduction of exhaust emission with new water injection system in a diesel engine. SAE paper 960033, 1996.

Tsukahara

Tadashi

Yoshimoto

Influence of fuel properties on the combustion in diesel engine driven by the emulsified fuel. Jap. Soc. Mech. Engrs, 1982, 25(202), 612–619.

Yoshimoto

Tsukahara

Kuramoto

Improvement of BSFC by reducing diesel engine cooling losses with emulsified fuel. SAE paper 962022, 1996.

Gunerman

R. W.

Russell

R. L.

Emission and efficiency benefits of emulsified fuels to internal combustion engines. SAE paper 972099, 1997.

Ishida

Chen

Z. L.

An analysis of the added water effect on NO formation in D.I. diesel engines. SAE paper 941691, 1994.

Arun

S. P. S.

Photographic study of fuel spray ignition in a rapid compression machine. SAE paper 86065, 1986.

Ahn

S. K.

Matsui

Kamimoto

Matsuoka

Measurement of flame temperature distribution in a DI diesel engine by means of image analysis of nega-color photographs. SAE paper 810183, 1981.

10.

Heywood

J. B.

Internal Combustion Engine Fundamentals, 1988, pp. 497–502 (McGraw-Hill, New York).

11.

Sheng

H. Z.

Chen

C. K.

The droplet group micro-explosions in W/O diesel fuel emulsion sprays. SAE paper 950855, 1995.