Engine room fire safety evaluation of ammonia as marine fuel

Ammonia fuelled vessels are not a distant reality anymore. This paper will examine whether ammonia constitutes a greater fire hazard than conventional fuel types in the event of an engine room fire. It is to showcase how a realistic engine room fire outbreak can be modelled for a case vessel of 50,000 dead weight tonnage bulk carrier. Four simulation scenarios are then modelled, and their outputs are analysed and discussed. From the simulations process, it was evident that an ammonia fire does not present a greater danger than a diesel or natural gas fire. Ammonia’s fire behaviour was better than the conventional fuel fires with relation to soot formation and potential machinery damage. An ammonia fire provides a better evacuation window; it has more even temperature distribution through the engine space and the developed flame temperatures were lower. The main conclusion of this project is that due to ammonia flammability limits and thermal properties, a dispersion would take time and thus reduce the likelihood of an ammonia fire occurring and is manageable.