Assessing the feasibility of increasing engine efficiency through extreme compression

作者：Miller S L^*; Svrcek M N; Teh K Y; Edwards C F

来源：International Journal of Engine Research, 2011, 12(3): 293-307.

DOI：10.1177/1468087411404299

• entropy generation
• combustion
• extreme compression
• engine efficiency
• high compression ratio
• low irreversibility

Operating simple-cycle chemical engines at extremely high compression ratios can, theoretically, increase thermal efficiency by nearly a factor of two. To operate at these significantly higher compression ratios, a new engine architecture is required which is inherently compatible with the higher temperatures and pressures present at these conditions. In addition, the design must manage heat transfer, piston-cylinder sealing and friction, the combustion event, and emissions in order to be successful. To test feasibility of this strategy, a single-shot, free-piston device was constructed which operates at compression ratios of up to 100:1. Air-compression experiments are used to characterize the device and its losses - a combination of heat transfer out of the cylinder and mass transfer past the piston sealing rings. Preliminary experiments using a lean, diesel-like combustion strategy are performed with indicated efficiencies ranging from 52 to 60 per cent for compression ratios of 30-100. These high efficiencies indicate initial feasibility and support further research and engineering.

• 出版日期2011-6