Assessment of hydrogen-based dual fuel engine on extending knock limiting combustion

The key intention of this study is to effectively utilize the Madhuca longifolia oil (ML) in a diesel engine. Dual fuel mode is one of the most promising research concepts in diesel engine arena that intends to improve the performance and reduce the smoke emission. In this work, hydrogen was injected into intake manifold as primary fuel whereas the ML was injected directly into the cylinder as pilot fuel in the setup that had a single cylinder constant speed diesel engine. The performance of the engine was increased from 25% with neat ML operation to 28.5% with hydrogen-based dual fuel mode. However, the hydrogen combustion resulted in knocking, thus it had a direct impact on BTE as well. Water Injection (WI) method was used to extend the knock limit and to increase the hydrogen energy share. The researcher observed 18% and 76% improvements in BTE and smoke emission from 5% of water using mass fraction along with hydrogen. The hydrogen energy share was increased from 6% to 8.5% with 5% WI. A distinctive attempt i.e., addition of ALPG was attempted on behalf of offsetting the knock and increasing the hydrogen energy share. ALPG was inducted along with hydrogen in the range of 1, 1.5 and 2 l/m. Interestingly, 24% improvement in BTE was noted when 1.5 l/m of ALPG was inducted. In addition to this, 83% smoke emission was reduced remarkably. Overall performance of the engine was improved by extending the knock limit, WI and ALPG induction along with hydrogen.