Effects of hydrogen-enriched LPG fuelled engine on exhaust emission and thermal efficiency

LPG 엔진에서 수소첨가에 따른 배기 성능과 열효율에 미치는 영향

  • Kim, jinho (University of Keimyung) ;
  • Cho, unglae (University of Keimyung) ;
  • Choi, gyeungho (University of Keimyung)
  • Published : 2001.09.15

Abstract

The purpose of study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The test engine was named heavy-duty variable compression ratio single cylinder engine (VCSCE). The fuel supply system provides LPG/hydrogen mixtures based on same heating value. Various sensors such as crank shaft position sensor (CPS) and hall sensor supply spark timing data to ignition controller. Displacement of VCSCE is $1858.2cm^3$. VCSCE was runned 1400rpm with compression ratio 8. Spark timing was set MBT without knocking. Relative air-fuel ratio(${\lambda}$) of this work was varied between 0.76 and 1.5. As a result, i) Maximum thermal efficiency occurred at ${\lambda}$ value 1.0. It was shown that thermal efficiency was increased approximately 5% with hydrogen enrichment at same ${\lambda}$ value. ii) Engine-out carbon monoxide (CO) emissions were decreased at a great rate under LPG/hydrogen mixture fuelling. iii) Total hydrocarbon (THC) emission was much exhausted in rich zone, same as CO. But THC was exhausted a little bit more in lean zone. iv) Finally, engine-out oxides of nitrogen (NOx) was increased with ${\lambda}$ value 1.0 zone at a greater rate with hydrogen enrichment due to high adiabatic flame temperature.

Keywords

VCSCE(Variable compression ratio single-cylinder engine);LPG(Liquefied petroleum gas);compression ratio;MBT(Maximum brake torque timing);${\lambda}$(Relative air-fuel ratio)