An effort to enhance hydrogen energy share in a compression ignition engine under dual-fuel mode using low temperature combustion strategies

• Published in: Applied energy Vol. 146; pp. 174 - 183
• Main Authors: Chintala, V., Subramanian, K.A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-05-2015
• Subjects: Diesel and B20 pilot fuels; Dual-fuel engine; Hydrogen; Retarded injection timing; Water injection; Water injection; Retarded injection timing; Diesel and B20 pilot fuels; Hydrogen; Dual-fuel engine
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2015.01.110

•H2 energy share increased from 18% with DDM to 36% with WDM (water injection).•H2 energy share improved marginally with retarded injection timing mode (RDM).•Energy efficiency increased with increasing amount of H2 in dual-fuel engine.•NOx emission decreased with water injection and retarded pilot fuel injection.•HC, CO and smoke emissions increased slightly with low temperature combustion.
A limited hydrogen (H2) energy share due to knocking is the major hurdle for effective utilization of H2 in compression ignition (CI) engines under dual-fuel operation. The present study aims at improvement of H2 energy share in a 7.4kW direct injection CI engine under dual-fuel mode with two low temperature combustion (LTC) strategies; (i) retarded pilot fuel injection timing and (ii) water injection. Experiments were carried out under conventional strategies of diesel dual-fuel mode (DDM) and B20 dual-fuel mode (BDM); and LTC strategies of retarded injection timing dual-fuel mode (RDM) and water injected dual-fuel mode (WDM). The results explored that the H2 energy share increased significantly from 18% with conventional DDM to 24, and 36% with RDM, and WDM respectively. The energy efficiency increased with increasing H2 energy share under dual-fuel operation; however, for a particular energy share of 18% H2, it decreased from 34.8% with DDM to 33.7% with BDM, 32.7% with WDM and 29.9% with RDM. At 18% H2 energy share, oxides of nitrogen emission decreased by 37% with RDM and 32% with WDM as compared to conventional DDM due to reduction of in-cylinder temperature, while it increased slightly about 5% with BDM. It is emerged from the study that water injection technique is the viable option among all other strategies to enhance the H2 energy share in the engine with a slight penalty of increase in smoke, hydrocarbon, and carbon monoxide emissions.