Investigation of the effect of compression ratio on the energetic and exergetic performance of a CI engine operating with safflower oil methyl ester.

This study examines the energy and exergy analyses for a single-cylinder, four-stroke, direct-injection, compression-ignition (CI) engine when it was run on the safflower (Carthamus tinctorius L.) oil methyl ester (SOME) and traditional diesel (as reference fuel) at various engine loading conditions (from 25% to full load in 25% steps) at a fixed speed of 1500 rpm. In addition, the compression ratio (CR) was changed between 12:1 and 18:1 in order to monitor its effect on the engine characteristics. The experimental outcomes obtained from the above-stated analyses showed that the tested engine spent more alternating fuel because of its lower energy content than that of diesel fuel in an effort to ensure the output power to be the same for the test fuels. Furthermore, the results exhibited that the energetic and exergetic efficiency enhanced with the increase of load and CR. In this contest, at the CR of 18:1 and full load, the maximum energy efficiency values for SOME and diesel fuel were found to be 28.67% and 29.78%, respectively meanwhile the related exergetic efficiency values were calculated to be 26.41% and 27.94%, respectively. The minimum exergy destruction figures were revealed at the CR of 18:1 and a load of 100% for tested fuels with the findings of 56.59% for SOME and 55.22% for diesel fuel. In conclusion, the results of the conducted analyses for the tested diesel engine powered by SOME appeared to be fairly close to those of diesel fuel at various loads and CRs. SOME will eventually be classified as an alternate fuel to petroleum-based diesel fuel. [ABSTRACT FROM AUTHOR]