Near-zero emissions with high thermal efficiency realized by optimizing jet plume location relative to combustion chamber wall, jet geometry and injection timing in a direct-injection hydrogen engine

• Published in: International journal of hydrogen energy Vol. 44; no. 18; pp. 9456 - 9465
• Main Authors: Takagi, Yasuo, Oikawa, Masakuni, Sato, Ryota, Kojiya, Yoshihisa, Mihara, Yuji
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05.04.2019
• Subjects: Cooling loss; Hydrogen direct injection; Hydrogen engine; NOx; Spark ignition engine; Thermal efficiency; Hydrogen engine; Spark ignition engine; Cooling loss; Thermal efficiency; Hydrogen direct injection; NOx
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2019.02.058

Thermal efficiency was substantially improved and NOx emissions were reduced to a level at a single-digit ppm with PCC combustion by optimizing such characteristics as the direction, number and diameter of the injected jet and controlling the injection timing and also by combining with combustion of lean mixture. Output power declined by lean mixture was recovered by supercharging in keeping NOx emissions remained at the same level, while thermal efficiency was improved furthermore by slightly re-optimizing jet conditions. As a result, hydrogen engine which does not emit any CO2 and particulate matter in principle is worth to be called near-zero emission engines in both name and reality. Thermal Efficiency and NOx Emission Level Achieved for all Variation of Injection Angle in MBT and LBT Conditions. [Display omitted] •Development of near-zero emission hydrogen engines.•Attainment of NOx reduction with high thermal efficiency and output power.•Optimization of hydrogen jet configuration and concentration by nozzle design.