Enhancement and Analytical Assessment of Single Cylinder Spark Ignition Engine Operated on Liquefied Petroleum Gas (LPG)

Abstract

Utilizing gaseous fuels, such as Liquefied Petroleum Gas (LPG) and Liquefied Natural Gas (LNG), has become widespread in the realm of commercial vehicles. This undertaking is driven by the primary goal of adapting an existing gasoline-fuelled Spark Ignition (SI) engine to seamlessly operate with LPG. Simultaneously, the secondary aim of this Endeavor involves a meticulous examination of the theoretical performance of the engine when fuelled with both LPG and gasoline. A comprehensive analytical comparison has been conducted to scrutinize the engine's performance under these diverse fuel scenarios. The engine under consideration for this scholarly pursuit is a four-stroke single cylinder 7 kW TVS King Bajaj engine. To achieve the desired modification, a meticulously chosen first-generation LPG conversion kit has been identified and seamlessly integrated into the existing gasoline-fuelled engine. This conversion kit comprises essential components such as a mixing unit, pressure regulator, vacuum lock-off and filter, selector switch, solenoid valve, multi-functional valve, and LPG cylinder. After the successful adaptation of the engine to run on both fuels, it was mounted on a water dynamometer to systematically assess its performance and emission characteristics. The outcomes of the analytical engine performance evaluation are remarkable. The brake power output exhibited an impressive 7.2% improvement, coupled with a noteworthy 1.98% reduction in brake specific fuel consumption when the engine operated on LPG instead of gasoline. Moreover, when running on LPG, the engine's brake thermal efficiency experienced a commendable boost of 2.66%. These discerning parametric analyses underscore LPG as an up-and-coming alternative to gasoline, not only in terms of performance but also in consideration of anti knock properties, emission characteristics, and the cost-effectiveness of the fuel.