| EFFECTS OF VARYING EXCESS AIR RATIOS ON A
HYDROGEN-FUELED SPARK IGNITION ENGINE WITH
PFI AND DI SYSTEMS UNDER LOW-LOAD CONDITIONS |
| Yongrae Kim 1, Cheolwoong Park 1, Young Choi 1, Junho Oh 2, Jeongwoo Lee 2,3 |
1Korea Institute of Machinery and Materials
2Jeonbuk National University
3Chungnam National University |
|
|
|
|
|
|
|
| ABSTRACT |
|
In this study, the effects of varying excess air ratios on a 2.0 L naturally aspirated (NA) hydrogen-fueled spark
ignition (SI) engine were evaluated under low-load conditions by using port fuel injection (PFI) and direct injection (DI)
systems. The engine speeds chosen were 1,200 rpm and 2,000 rpm. The excess air ratio was varied between 1.0 and 2.7 by
controlling the throttle and hydrogen fuel rate under a brake mean effective pressure of 0.4 MPa. The combustion mechanism,
net indicated thermal efficiency (ITE), brake thermal efficiency (BTE), gas exchange efficiency, mechanical efficiency, and
engine-out nitrogen oxide (NOx) emissions were mainly discussed. The results indicated that the main combustion duration
of PFI was shorter than that of DI due to its homogeneity, and the ITE values of PFI were similar or slightly lower than those
of DI. However, as the mechanical efficiency of DI was higher than that of PFI, the BTE values of DI were always higher
than those of PFI (the maximum BTE was 39.7 %). The NOx reduction potential of DI was superior to that of PFI due to
stratified combustion, and its lowest value was 0.03 g/kWh. In addition, as the CO2 concentration in the exhaust gas increased,
the brake-specific CO2 reduced (< 5.71 g/kWh). |
| Key Words:
Direct injection, Efficiencies, Engine-out emissions, Excess air ratio, Hydrogen-fueled internal
combustion engine, Port fuel injection |
|
|
|
Corresponding Author.
Jeongwoo Lee , Email. 
Preview
Full text via DOI
Download Citation 
Print 
