Use of water diesel emulsions in diesel engines has resulted in drastic reductions in NOx and smoke levels, while the thermal efficiency is also improved. The objective of this work is to evaluate the effects of using water diesel emulsion as the pilot fuel in a dual fuel engine with LPG as the primary fuel. Tests were conducted on a single cylinder constant speed DI diesel engine. An emulsion with a water to diesel ratio of 0.4:1 was used. Performance, HC, CO, NOx, smoke emissions and combustion parameters were obtained and compared with the case where pure diesel was used as the pilot fuel. At high loads, the brake thermal efficiency with the emulsion as the pilot fuel was better than that with diesel. NOx levels were drastically reduced. The already low smoke levels were reduced further with the emulsion. There was an adverse effect on HC and CO emissions. The maximum rate of pressure rise and peak pressure were also higher with the emulsion. The use of the emulsion was not advantageous at low loads. Copyright © 2001 Society of Automotive Engineers, Inc.

A Ramesh

Department of Mechanical Engineering

Diesel engines

efficiency

Emulsification

Engine cylinders

Fuels

Nitrogen oxides

smoke

Adverse effect

Brake thermal efficiency

CONSTANT SPEED

DI diesel engine

MAXIMUM RATE OF PRESSURE RISE

SINGLE CYLINDERS

SMOKE EMISSION

Thermal efficiency

DUAL FUEL ENGINES

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Investigation on the use of Water - Diesel Emulsion in a LPG - Diesel Dual Fuel Engine

SAE Technical Papers

Performance of a single-cylinder, water-cooled, direct-injection diesel engine on dual-fuel operation with Jatropha oil (JO) as pilot fuel and orange oil as primary fuel was evaluated. Constant load test at different power outputs was conducted at the rated speed of 1500 r/min with varying orange oil quantities. The loads were fixed as 20 per cent, 40 per cent, 60 per cent, 80 per cent, and 100 per cent. In dual-fuel operation with orange oil induction, the thermal efficiency of JO was increased mainly at high power outputs. Maximum thermal efficiency with JO was found as 29 per cent at 31 per cent of orange oil induction at 100 per cent load. Smoke was reduced significantly with all orange oil induction rates at all power outputs in dual-fuel operation with JO. It was reduced from 4.4 to 3.3 BSU (Bosch Smoke Units) with JO at the maximum efficiency point at 100 per cent load. HC emissions were increased further at all power outputs in the dual-fuel mode with all rates of orange oil induction. Dual-fuel operation increased the ignition delay of JO. However, peak pressure and energy release rates were improved in the dual-fuel operation with orange oil induction. In general, dual-fuel operation with orange oil as inducted fuel with JO as pilot fuel showed inferior performance and emissions at part loads. It is concluded that the JO as pilots fuel and orange oil as the inducted fuel could be used in diesel engines with reduced smoke levels and improved thermal efficiencies with no major detoriation in performance. © 2011 Authors.

Fulltext

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy

A comprehensive study on performance, emission, and combustion characteristics of a dual-fuel engine fuelled with orange oil and Jatropha oil

A diesel engine was operated with karanja oil, bio-diesel obtained from karanja oil (BDK) and diesel as pilot fuels while LPG was used as primary fuel. LPG supply was varied from zero to the maximum value that the engine could tolerate. The engine output was kept at different constant levels of 25%, 50%, 75% and 100% of full load. The thermal efficiency improved at high loads. Smoke level was reduced drastically at all loads. CO and HC levels were reduced at full load. There was a slight increase in the NO level. Combustion parameters indicated an increase in the ignition delay. Peak pressure and rate of pressure rise were not unfavorably affected. There was an increase in the peak heat release rate with LPG induction. The amount of LPG that could be tolerated with out knock at full load was 49%, 53% and 61% on energy basis with karanja oil, BDK and diesel as pilots. On the whole it is concluded that LPG can be inducted along with air in order to reduce smoke levels and improve thermal efficiency of vegetable oil and bio-diesel fuelled diesel engines. Copyright © 2006 SAE International.

Studies on dual fuel operation of karanja oil and its bio-diesel with LPG as the inducted fuel

The engine, which uses both conventional diesel fuel and LPG fuel, is referred to as ‘LPG–diesel dual fuel engines’. LPG dual fuel engines are modified diesel engines which use primary fuel as LPG and secondary fuel as diesel. LPG dual fuel engines have a good thermal efficiency at high output but the performance is less during part load conditions due to the poor utilization of charges. This problem can be overcome by varying factors such as pilot fuel quantity, injection timing, composition of the gaseous fuel and intake charge conditions, for improving the performance, combustion and emissions of dual fuel engines. This article reviews about the research work done by the researchers in order to improve the performance, combustion and emission parameters of a LPG–diesel dual fuel engines. From the studies it is shown that the use of LPG in diesel engine is one of the capable methods to reduce the PM and NOx emissions but at same time at part load condition there is a drop in efficiency and power output with respect to diesel operation.

Alexandria Engineering Journal

LPG diesel dual fuel engine – A critical review

Journal	SAE Technical Papers
Publisher	SAE International
ISSN	01487191
Open Access	No