The influence of hydrogen as a supplementary fuel on the characteristics of CI engines running on Calophyllum inophyllum oil diesel blend

Abstract

Hydrogen gas is largely used as a significant supplementary fuel for CI engine due to its clean combustion, high energy content, and abundance. In this research, the engine was made to operate in dual fuel mode with Calophyllum Inophyllum Oil (CIO) diesel blend and hydrogen gas. CIO was directly injected into the combustion chamber through direct injector and hydrogen gas in the intake manifold. The engine was subjected to operate at different loads ranging from 0 to 100 % with the interval of 25 %. The CIO was blended with diesel in two proportions with 20 % and 40 %. The hydrogen gas was supplied at three different flow rates of 10, 20 & 30 L per minute. The maximum energy share of hydrogen induction was limited to 14.38%, 13.05%, and 11.28%, respectively, at full load for diesel, P20, and P40 respectively. Brake thermal efficiency for P20 and P40 at maximum energy share is increased by around 5.34% and 2.01% compared to diesel at full load conditions and also, hydrogen induction with CIO blends shows a promising reduction of pollutants such as CO by 14.89%, HC by 90.1%, and smoke by 32.65% compare with neat diesel. A prolonged ID ignition delay was also observed by the inclusion of pilot fuel and hydrogen due to pre-ignition of the fresh charge. Moreover, this investigation found that the blend of P20 with 13.05% hydrogen sharing at full load significantly improved performance, combustion, and emissions characteristics.