Modelling heat transfer and fluid flow in a ship engine room using CFD analysis to evaluate and improve ventilation

Abstract

Considering that about 90% of international trade is transported via sea and ship ventilation systems consume between 3.5% and 5.5% of the ship’s rated power, ship energy consumption is of particular interest and modelling and enhancing ventilation systems are vital to reducing and optimising energy consumption. Using Computational Fluid Dynamics (CFD) simulation, modelling heat transfer and airflow patterns helped us improve the ventilation system and temperature distribution, provide thermal comfort for staff and equipment, and increase energy efficiency. We discussed the radiation effect in CFD analysis; it affected wall temperatures significantly and temperature contours to some extent; it raised air temperatures by 3 K and wall temperatures by 14 K in some areas; this issue has not been considered in previous analyses. Considering seven different engine room configurations, we analysed temperature distribution, air terminal streamlines and other parameters to choose the best. We examined four energy-saving plans for the best configuration, and airflow was reduced by 13.8% and fan power by 36% based on the temperature distribution. By improving the engine room ventilation system, average engine room temperature, heat removal efficiency, combustion air temperature, and temperature distribution developed. The analysis of air terminals included assessing their streamlines, determining areas they circulated, and customising their airflow; in addition to vertical and horizontal air terminals at the top or bottom of the engine room, we also examined a separate air terminal for engine combustion air, this tool has been used very little before.

A Numerical Study on the Smoke Dispersion and Temperature Distribution of a Ship Engine Room Fire Based on OpenFOAM

“…Numerical analyses allow us to obtain the temperature changes in different materials during combustion and to understand their effects on the outside world [32][33][34][35]. The importance of avoiding potential human injury and property damage from cabin fires is significant, and it follows that the realization of unmanned improvements to the intricate duct wiring in the nacelle [36] and an optimized engine structure [37][38][39] can also minimize the risk of human casualties. In summary, conducting numerical analyses combined with systematic tools provides in-depth analyses of the cabin fire problem, examining the factors of fire spread, temperature distribution, and hazardous gas diffusion from different perspectives, and providing new insights and guidance for research and practice in the field of ship safety.…”