Energy and exergy based performance evaluation of variable compression ratio spark ignition engine based on experimental work

The present communication deals with the study of energy and exergy analysis of variable compression ratio four stroke spark ignition engine based on experimental work. The effect of varying compression ratio from 6 to 10 is analysed on both energy and exergy based approach. Both energy and exergy distributions are evaluated at different compression ratios for different rpm. The results show that as compression ratio increased from 6 to 10, the maximum power output is obtained at compression ratio 10 at 1800 rpm i.e. 3.80 kW. The maximum energy and exergy efficiencies are found to be 28.55% and 27.35% respectively at compression ratio 9 for 1200 rpm. Entropy generation found to be maximum for compression ratio 7 i.e. 36.47 W/K at 1800 rpm and minimum for compression ratio 9 i.e. 15.68 W/K at 1200 rpm. The results of this work revealed that exergy destruction of 10.87 kW found to be maximum at compression ratio 7 for 1800 rpm. This conclusion drawn from the study that applying both energy and exergy analysis give a more valuable understanding of performance and improvement of internal combustion engines by locating and then reducing the exergy loss at that location. Application of alternative gaseous fuels, exhaust heat recovery techniques, lean and low temperature combustion strategies reduce these exergy losses.