Comparative study on combustion and emissions between methanol port-injection engine and methanol direct-injection engine with H2-enriched port-injection under lean-burn conditions. (15th November 2019)

• Record Type: Journal Article
• Authors: Gong, Changming; Li, Zhaohui; Yi, Lin; Liu, Fenghua
• Is Part Of: Energy conversion and management. Volume 200(2019)
• Publication Date: 2019-11-15
• Subjects: Spark-ignition engine -- Port-injection -- Direct-injection -- Methanol -- Hydrogen -- Lean-burn; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2019.112096
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Lean-burn strategy of H2 /methanol dual-fuel dual-injection engines is proposed. Lean-burn characteristics of homogeneous and stratified combustion modes are compared. HPI + MDI engines for 6% H2 addition can effectively extend lean-burn limit to excess air ratio 2.2. The BSHC and BSCO emissions of HPI + MPI engines are lower than these of HPI + MDI engines. The BSNOX and soot emissions of HPI + MPI engines are higher than that of HPI + MDI engines. Abstract: Lean-burn is an effective way to improve thermal efficiency and reduce emissions of spark-ignition (SI) engines. A hydrogen (H2 ) enrichment combustion strategy can extend the lean-burn limits of SI engines. Two engines equipped with hydrogen and methanol dual-port injection (HPI + MPI) and hydrogen port injection plus methanol direct injection (HPI + MDI) were used to evaluate the lean-burn capability of SI engines. The lean-burn characteristics of homogeneous and stratified combustion modes were compared. The results showed that H2 addition was more conducive to extending the lean-burn limit of the direct-injection methanol engine and achieving high indicated mean effective pressure (IMEP) than the port-injection methanol engine. HPI + MDI engines with 6% H2 addition effectively extended the lean-burn limit to an excess air ratio of 2.2. H2 addition compensated for the power drop caused by the decrease in volumetric efficiency and speed up combustion under lean-burn conditions. H2 addition could also realize stable combustion under super lean-burn conditions for HPI + MDI engines. The BSHC and BSCO emissions of HPI + MPI engines were lower than those of HPI + MDI engines, but the BSNOX and soot emissions were higher. H2 addition decreases BSCO2 emissions at the same excess air ratio for both the HPI + MPI and HPI + MDI engines.