Retrofitting a high-speed marine engine to dual-fuel methanol-diesel operation: A comparison of multiple and single point methanol port injection

Performance and emissions of a high-speed marine dual-fuel engine operating with methanol-water blends as a fuel

“…In dual-fuel operation the effects of the cooling effect of methanol are known [12] [13] [17]. With regard to the maximum DSR, at high load lower intake temperatures decrease the possibility for pre-ignition and knock [21], but at low load the lower intake temperatures are responsible for misfire at high diesel replacement. The lower in-cylinder temperatures with increasing methanol energy lead to (1) higher brake thermal efficiency (BTE) (especially at higher loads) due to lower heat losses and a more rapid combustion, and to (2) lower NOx formation.…”

“…The results of the first measurement campaign have been published in [17]. In [21], two different methanol injection strategies were compared: a single point injection (SPI) of methanol in the intake duct and a multiple point injection (MPI) just before each valve of the six cylinders. In this paper, the MPI strategy has been used for injecting MeOH-W blends.…”

“…Methanol can be injected directly in the cylinder into a burning diesel jet [15] [16] or it can be fumigated in the intake manifold, at a single point in the intake or at multiple points before the intake valves [12] [17] [20]. In this paper, the fumigation concept is used as it is the most convenient engine retrofit solution: it has the advantage of a methanol circuit at low pressure and that no engine modifications are required because methanol can be injected in the more easily accessible intake manifold [21].…”

“…Dierickx et al [21] compared two methanol injection strategies: at high load lower DSRs were reached with a single point methanol injection than with a multiple point methanol injection. Water is known to be a knock suppressant from experiments on spark ignition (SI) engines [4] [24] [25].…”

Current Status of Research on Methanol as an Alternative Fuel to Conventional Fuels

“…Methanol, as one of many alternative fuels, has attracted a lot of attention in recent years by virtue of its wide source and versatility. Methanol has distinctive characteristics compared to traditional fossil fuels [5][6]. For example, it has high octane number and good anti-detonation property, which can increase the engine compression ratio to improve engine performance and reduce fuel consumption.…”