Influence of Multiple Injection Strategies on Performance and Emissions for Methanol PPC operation in a Heavy-Duty CI Engine 2020-01-0556
There is growing global interest in using renewable alcohols to reduce the greenhouse gases and the reliance on conventional fossil fuels. Recent studies show that methanol combined with Partially Premixed Combustion (PPC) provides clear performance and emission benefits compared to conventional diesel diffusion combustion. Nonetheless, a narrow operating window with simultaneously low NOx and HC emissions can be stated as the main PPC drawback in light load conditions when a single injection strategy is used. Thus, the present experimental study has been carried out to investigate the influence of multiple injection strategies on the performance and emissions with methanol fuel in partially premixed combustion. Specifically, the main objective is to improve the NOx-HC trade-off, as well as the gross indicated efficiency (GIE) compared to single injection strategy results. The work was performed with a single-cylinder heavy-duty engine, operated at 4 bar gross indicated mean effective pressure (IMEPg), and an engine speed of 1200 rpm. Double and triple injections were implemented with varying dwells, injection timings, and fuel mass proportions. The experimental results were analyzed with a merit function to select the optimal injection strategy. Concerning emissions, the constraints for the merit function were based on the EURO VI limits, while the GIE for single injection was used to define the performance constraint. The results revealed that the triple injection strategy gives improved performance and lower emissions compared to the double and single injection strategies.
Amir Aziz, Antonio Garcia, Clarisse Pinto Dos Santos, Martin Tuner
Lund University, Universitat Politecnica de Valencia, ISAE-ENSMA