[가솔린엔진부문] 공연비 계산법에 대한 고찰 : Part 3 - 공연비 계산 방식들의 비교

This paper is the third of 5 companion papers which compare the method of Air-Fuel ratio determination. In the previous works, the expansion of Eltinge chart to arbitrary fuel composition, unburned hydrocarbon compensation in Eltinge chart and comparison of Spindt and Eltinge was discussed. In addition to Eltinge and Spindt, however, there are many methods which calculate Air-Fuel ratio from exhaust emission. Among these methods, carbon balance and oxygen balance have been formulated and widely used. Also, linear formula from statistical method is being used in the field due to its simplicity and convenience. In this paper, these various methods are evaluated and compared with Eltinge results and new linear formula is proposed for the gasoline fuel. The results show that the corrected carbon balance equation has excellent agreement with Eltinge and Spindt. On the other hands, the oxygen balanced one has a limitation according to the mixture state and AFR. Newly proposed linear equation has good compatibility with Eltinge and Spindt up to AFR 17.