Experimental study on thermal efficiency and emission characteristics of a lean burn hydrogen enriched natural gas engine

To explore a suitable combustion strategy for natural gas engines using jet ignition, lean burn with air dilution, stoichiometric burn with EGR dilution and lean burn with EGR dilution were investigated in a single-cylinder natural gas engine, and the performances of two kinds of jet ignition technology, passive jet ignition (PJI) and active jet ignition (AJI), were compared. In the study of lean burn with air dilution strategy, the results showed that AJI could extend the lean limit of excess air ratio (λ) to 2.1, which was significantly higher than PJI’s 1.6. In addition, the highest indicated thermal efficiency (ITE) of AJI was shown 2% (in absolute value) more than that of PJI. Although a decrease of NOx emission was observed with increasing λ in the air dilution strategy, THC and CO emissions increased. Stoichiometric burn with EGR was proved to be less effective, which can only be applied in a limited operation range and had less flexibility. However, in contrast to the strategy of stoichiometric burn with EGR, the strategy of lean burn with EGR showed a much better applicability, and the highest ITE could achieve 45%, which was even higher than that of lean burn with air dilution. Compared with the most efficient points of lean burn with pure air dilution, the lean burn with EGR dilution could reduce 78% THC under IMEP = 1.2 MPa and 12% CO under IMEP = 0.4 MPa. From an overall view of the combustion and emission performances under both low and high loads, the optimum λ would be from 1.4 to 1.6 for the strategy of lean burn with EGR dilution.

Download Full-text

9733314 Consideration of thermal efficiency of a heavy duty turbo-charged lean-burn natural gas engine Makoto Oguchi, Takayuki Sakai, Eiji Kuroda, Nobuo Iwai (Japan Automobile Research Institute Inc.)

JSAE Review ◽

10.1016/s0389-4304(98)90417-9 ◽

1998 ◽

Vol 19 (1) ◽

pp. 108-109 ◽

Cited By ~ 1

Keyword(s):

Natural Gas ◽

Thermal Efficiency ◽

Heavy Duty ◽

Lean Burn ◽

Gas Engine ◽

Natural Gas Engine ◽

Research Institute

Download Full-text

Effects of Spark Advance Angle on Combustion and Emission Characteristics of a Compressed Natural Gas Engine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.6085 ◽

2011 ◽

Vol 383-390 ◽

pp. 6085-6090

Author(s):

Xiao Na Sun ◽

Hong Guang Zhang ◽

Xin Wang ◽

Dao Jing Wang ◽

Guo Yong Zheng ◽

...

Keyword(s):

Natural Gas ◽

Pressure Rise ◽

Emission Characteristics ◽

Nox Emissions ◽

Lean Burn ◽

Compressed Natural Gas ◽

Gas Engine ◽

Natural Gas Engine ◽

Peak Cylinder Pressure ◽

Co Emission

The effects of spark advance angle on combustion and emission characteristics of a compressed natural gas engine have been investigated experimentally in this paper. The experimental data was conducted under various excessive air coefficient conditions using an electronic ignition system developed self-dependently. The results show that the peak cylinder pressure and peak rate of pressure rise ascends with the increase of spark advance angle in a certain extent, and their corresponding location are advanced. The CO emission keeps almost the same as the spark advance angle varies in the overall mode range. The HC and NOx emissions ascend with the increase of spark advance angle under the condition that excessive air coefficient is near the theoretical value. Under the lean-burn condition, the HC and NOx emissions are almost the same while the spark advance angle varies.

Download Full-text