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Why Liquid Phase LPG Port Injection has Superior Power and Efficiency to Gas Phase Port Injection
ISSN: 0148-7191, e-ISSN: 2688-3627
Published August 05, 2007 by SAE International in United States
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This paper reports comparative results for liquid phase versus gaseous phase port injection in a single cylinder engine. It follows previous research in a multi-cylinder engine where liquid phase was found to have advantages over gas phase at most operating conditions. Significant variations in cylinder to cylinder mixture distribution were found for both phases and leading to uncertainty in the findings. The uncertainty was avoided in this paper as in the engine used, a high speed Waukesha ASTM CFR, identical manifold conditions could be assured and MBT spark found for each fuel supply system over a wide range of mixtures. These were extended to lean burn conditions where gaseous fuelling in the multi-cylinder engine had been reported to be at least an equal performer to liquid phase.
The experimental data confirm the power and efficiency advantages of liquid phase injection over gas phase injection and carburetion in multi-cylinder engine tests. Analysis shows the charge state at the end of compression is the major contributor to the performance difference. Secondary differences such as the mixture homogeneity also have an important influence. The lower temperature combustion with liquid phase LPG also delivers substantial NOx emission reduction.
Suggestions are made for overcoming the deficiency of gaseous phase injection which may be preferred as its application avoids the high cost of the high pressure in-tank LPG pump needed for liquid phase injection.
CitationWatson, H. and Phuong, P., "Why Liquid Phase LPG Port Injection has Superior Power and Efficiency to Gas Phase Port Injection," SAE Technical Paper 2007-01-3552, 2007, https://doi.org/10.4271/2007-01-3552.
- Baker P A Watson H C MPI air-fuel Mixing for Gaseous and Liquid LPG SAE paper 2005-01-0246 2005
- Khan M A Watson H C Baker P A Liew G Johnston D SI Engine Lean-Limit Extension through LPG Throttle-Body Injection for Low CO 2 and NO x SAE paper 2006-01-0459 2006
- Watson H C Milkins E E Comparison and Optimization of Emission Efficiency and Power of Five Automotive Fuels in one Engine Int. J. Vehicle Design 3 463 476 1982
- Hamori Ferenc Exploring the Limits of Hydrogen Assisted Jet Ignition The University of Melbourne Australia 2005
- America Society for Testing Materials ASTM Manual of Engine Testing Methods For Rating Fuels ASTM America 1952
- Zakis G Alternative Ignition Systems for CNG in Diesel Applications Thesis of Master Engineering Science The University of Melbourne Australia 2003
- Taylor C F The Internal Combustion Engine in Theory and Practice The MIT Press Second 1 184 5 2005
- Ericsson L Andersson I An Analytic Model for Cylinder Pressure in a Four Stroke Engine SAE 2002-01-0371 2002
- Mehrani P Watson H C Joint NOx and Efficiency Optimization Using a PSO Algorithm SAE paper 2006-01-1109 2006
- Beroun S Blazek J Hajek T Salhab Z Thermodynamics of working cycle of spark ignition engine with engineering simplifying, Lecture Notes Technical University of Liberec Czech Republic 1999
- Ianni J C. Kintecus Manual 2005 http://www.pcsoftland.com/education/chemistry/kintecus.htm
- Heywood J B Internal Combustion Engine Fundamentals McGraw-Hill 1998
- Farook Y Limits of Performance of an SI Engine Operating on LPG and Petrol The University of Melbourne Australia 1994
- Phuong P X Comparison of Liquid and Gaseous Liquefied Petroleum Gas Injection in a Spark Ignition Engine MEngSci Thesis Department of Mechanical and Manufacturing Engineering University of Melbourne 2006
- Sim H Lee K Chung N Sunwoo M A study on the injection characteristics of liquid-phase LPG injector for air-fuel ratio control Proceeding of the Institute of Mechanical Engineers 2005
- Sim H Sunwoo M Development and Validation of a Model for a Gaseous-Fuel Engine Proceeding of the Institution of Mechanical Engineers; Jun. 2004:218, 7; ProQuest Science Journal 697 2004