Exergy analysis of a single-cylinder four-stroke gasoline engine

TLDR: In this article , the authors performed an exergy analysis of a single-cylinder 4-stroke gasoline engine to determine how best its efficiency can be improved by optimizing the combustion temperature and reducing heat loss from the combustion chamber.

Abstract: In developing countries, the four-stroke single-cylinder gasoline engine finds wide use. Motorcycles, tricycles and household machines like vegetable grinding machines are but a few of the machinery which run on this engine. Researchers have found that this engine is inefficient and consumes a lot of fuel, in light of sustainability and energy efficiency, this study aimed to perform an exergy analysis of a single-cylinder 4-stroke gasoline engine to determine how best its efficiency can be improved. Parameters such as brake thermal power, exergy efficiency, the quantity of exergy destruction and the component of the engine which is the most influential on its efficiency were determined while varying the engine’s torque. A G200K1 Honda engine was used as the study material. At the lowest tested torque of 9.4Nm, a corresponding brake power output of 2.4609kW and efficiency of 17.07% was measured, while at a higher torque 9.70Nm, a corresponding brake power output of 2.5395kW and efficiency of 17.62% was measured. It was also found that for every 1.06% rise in torque there is a corresponding 1.80% rise in brake power and exergy efficiency. It was concluded from the findings that the bulk of energy waste in the system comes from the high-temperature gas released from the engine’s exhaust. For the overall efficiency of four-stroke single-cylinder gasoline engines to be improved, the exergy destruction due to combustion should be minimised by optimizing the combustion temperature and reducing heat loss from the combustion chamber.