Investigation of Effects of Intake Temperature on Low Load Limitations of Methanol Partially Premixed Combustion

Abstract

Methanol has unique properties as a fuel, and partially premixed combustion has promising results with high engine efficiency and low emissions. Low load studies with methanol partially premixed combustion are scarce, and the effect of intake temperature on low load methanol partially premixed combustion still remains an intriguing question. This study aims to investigate the effect of intake temperature on low load limitations of methanol partially premixed combustion by an experimental study. The engine was operated at 800 rpm under two different loads. The low load condition was performed at 3 bar Indicated mean effective pressure (IMEP), and the idle condition was commenced at 1 bar IMEP. From the results, it was seen that the intake temperature affected engine stability, engine performance, and engine emissions. The combustion stability decreased with the decrease of intake temperature. The ignition delay became longer and the peak cylinder pressure became smaller with lower intake temperature. The combustion efficiency reduced with the decrease of intake temperature from 0.99 to 0.96 at 3 bar IMEP, whereas it decreased from 0.99 to 0.98 at 1 bar IMEP for the single injection case and the split injection case. The thermodynamic efficiency remained constant at 0.43 at 3 bar IMEP, decreased from 0.30 to 0.28 at 1 bar IMEP for the single injection case, and reduced from 0.26 to 0.24 at 1 bar IMEP for the split injection case. The gross indicated efficiency increased from 0.41 to 0.42 at 3 bar IMEP, whereas it reduced from 0.29 to 0.28 and 0.26–0.24 at 1 bar IMEP at single injection and split injection, respectively. Total hydrocarbon emission increased, NO X emission decreased or remained constant, and CO emission remained constant with the decrease in intake temperature. Finally, the combustion phasing study was performed at 1 bar IMEP at constant intake temperature to determine the effect of the start of injection timing on the engine’s performance and the emissions under the idle condition.

Renewable Methanol as a Fuel for Heavy-Duty Engines: A Review of Technologies Enabling Single-Fuel Solutions

“…To address this limitation, the author suggests an increased compression ratio as a potential solution. Building upon this research, Zincir et al [100] delved deeper into the effects of intake air temperature on low-load methanol combustion under PPC conditions, utilizing a slightly elevated CR of 20. Despite this adjustment, intake temperatures of 100 • C or higher were still necessary, albeit enabling stable PPC operation under idle engine conditions, achieving a gross indicated efficiency of around 29%.…”

Improving Thermal Efficiency of Internal Combustion Engines: Recent Progress and Remaining Challenges

“…The results show that both PPC and HCCI of n-butanol can produce low NO x and close to zero smoke emissions while attaining diesel-similar engine efficiency. Zincir et al [208] investigated the impact of intake temperature on the limitation of PPC at a low load fueled by methanol. The results revealed that with higher intake temperatures, the GIE began to increase (41-42%) because of an increase in combustion efficiency (96-99%) affected by intake temperature.…”

Experimental study on combustion and emissions of a compression ignition engine fueled with gasoline

“…Therefore, the operating load of HCCI is seriously limited. [6][7][8] The heat release can be controlled by the mixture stratification in the cylinder. In order to improve the shortcomings of HCCI, the GCI (Gasoline Compression Ignition) combustion mode with mixture stratification in the cylinder was developed.…”