An experimental study on the effects of spring stiffness on the combustion and dynamic characteristics of a linear engine

We investigated the effects of the stiffness of springs applied to linear compressor chambers experimentally. The applied springs could prevent conflict between the engine piston head and engine head cover as well as be available to save the regenerative energy. The linear engine bore size was 30 mm, the maximum stroke was 31 mm and effective stroke volume of a cylinder was 25.45 cc. The spring stiffness was varied: 0, 0.5, 1.00, 2.9 and 14.7 N/mm. The linear engine was fueled with a pre-mixture combined with LPG (propane 99%) and air. As an experimental result, higher spring stiffness affected growth in regenerative energy and stroke. Also, IMEP was increased by rising stroke. Finally, increased IMEP and regenerative energy made more electricity than no spring.

[1]  Ocktaeck Lim,et al.  A study for generating power on operating parameters of powerpack utilizing linear engine , 2012 .

[2]  Ling Huang,et al.  An Opposed-Piston Free-Piston Linear Generator Development for HEV , 2012 .

[3]  Changlu Zhao,et al.  Experimental Study on Hydraulic Free Piston Diesel Engine , 2010 .

[4]  Douglas Carter,et al.  The Free Piston Power Pack: Sustainable Power for Hybrid Electric Vehicles , 2003 .

[5]  Zhen Huang,et al.  Motion characteristic of a free piston linear engine , 2010 .

[6]  Nadezhda A. Slavinskaya,et al.  Development Approach for the Investigation of Homogeneous Charge Compression Ignition in a Free-Piston Engine , 2013 .

[7]  Xiumin Yu,et al.  Permanent Magnetic Model Design and Characteristic Analysis of the Short-stroke Free Piston Alternator , 2012 .

[8]  Gangchul Kim,et al.  A Study for Development of Compact Powerpack used Hydrogen , 2010 .

[9]  Zhijun Wu,et al.  Simulations of Key Design Parameters and Performance Optimization for a Free-piston Engine , 2010 .

[10]  Richard J. Atkinson,et al.  Numerical Simulation of a Two-Stroke Linear Engine-Alternator Combination , 1999 .

[11]  Jaeheun Kim,et al.  The Effects of Spark Timing and Equivalence Ratio on Spark-Ignition Linear Engine Operation with Liquefied Petroleum Gas , 2012 .

[12]  Jan Hendrik Starcke,et al.  Numerical and Experimental Investigation of In-Cylinder Flow in a Loop-Scavenged Two-Stroke Free Piston Engine , 2012 .

[13]  R. Mikalsen,et al.  The control of a free-piston engine generator. Part 2: Engine dynamics and piston motion control , 2010 .

[14]  R. Mikalsen,et al.  The control of a free-piston engine generator. Part 1: Fundamental analyses , 2010 .

[15]  R. Mikalsen,et al.  A review of free-piston engine history and applications , 2007 .

[16]  Horst E. Friedrich,et al.  The Free Piston Linear Generator - Development of an Innovative, Compact, Highly Efficient Range Extender Module , 2013 .