Efficiency of fuel gas supply on LNG-fueled vessels

Abstract

The widespread use of LNG as a fuel for marine internal combustion engines makes to pay attention to the quality of gas fuel supply systems and its specifics. The objective of this paper is to review modern gas fuel supply systems and analyze their efficiency. The goal is to determine the most important parameters of gas fuel that affect the stability of the working process of marine dual-fuel engines and ways to maintain them within the specified limits. Evaluation of the gas fuel preparation efficiency is carried out on the basis of operational data obtained on the gas carrier vessel board. Data collection is carried out under non-standard operating conditions, which makes it possible to evaluate the quality of the resulting gas fuel with a time-varying composition of the initial natural gas. To analyze the obtained data, modern software, which is used by leading developers of marine diesel engines, is used (Wartsila Methane Number Calculator, AVL BoostTM and Python 3 statistic libraries). The analysis results are approximated for gas fuel supply systems for gas-fueled vessels, but not being gas carriers. This approximation is made taking into account the design features of gas fuel supply systems, since the specificity of the design imposes certain restrictions on the applicability of the conclusions obtained as a result of the previous analysis. Also, attention is paid to the accumulation of residual heavy hydrocarbons in bunker tanks, the excess of which can adversely affect the quality of gas fuel. Since there is no universal way to solve this problem, only general assumptions about possible ways to dispose of them have been made.