Parametric investigation of diesel–methanol dual fuel marine engines with port and direct injection
Year: 2024
Type: article
Abstract: Methanol is identified as a transitional fuel to improve the environmental footprint of shipping operations. However, high methanol shares cannot be achieved in premixed combustion marine dual-fuel engines. This study aims at parametrically investigating the impact of two types of methanol injection, namely port and direct injection, on marine engines by employing CFD modelling. A large medium speed marine engine with nominal power of 10.5 MW at 500 rev/m is considered. CFD models are developed for the engine diesel and dual fuel modes, whereas several cases with methanol energy fractions ranging up to 50% for the port injection and 95% for the direct injection cases are investigated. The CFD model for the diesel mode are validated against experimental data from several engine operating points. A parametric study considering the engine settings and methanol energy fraction is performed to identify the engine settings and limits for the combustion stable operation for high methanol shares. Subsequently, the comparative assessment of the investigated marine engine performance and emissions parameters is performed for the considered cases. This study results reveal that the methanol direct injection can use up to 95% methanol energy fraction retaining stable combustion conditions, whilst reducing NOx emissions by 85%. The engine indicated thermal efficiency increases at higher methanol energy fractions for direct injection, whereas opposite trade-offs are exhibited for premixed combustion. Methanol use shortens the combustion durations compared to the diesel mode, reducing the maximum temperature by 1–3%. This study provides valuable insights delineating the impact of the engine settings to the marine engines performance and emissions trade-offs, hence contributing to developing methanol fuelled marine engines.
Source: Fuel
Institutions: University of Strathclyde, Harbin Engineering University
Language: English
Subfield: Fluid Flow and Transfer Processes
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,200
OpenAlex ID: W4403626288