Studying different scenarios of operating air conditioning system in smoke management using computational fluid dynamics in naval ships

Abstract

Since the dawn of history maritime transport was an essential part of human communication and development which mandates the rapid development of the ship industry. It was accompanied by disasters caused by several factors among them fire played an important role. Fire can cause structural damage which affects ship safety and smoke which is life threating to passengers and ship crow. Trapped smoke in ship compartments if not ventilated or released can reach higher temperatures leading to flashover situation which enable fire propagation. The FLUENT CFD calculations were performed to analyze smoke generation and propagation in closed ship compartments. The time to reach flashover is also calculated. Based on how sealed and tight the compartment is three different scenarios where studied in this analysis: running air-condition while compartment door is open, stopped air-condition while compartment door is closed, and finally running air-condition while compartment door is closed. The calculations show that, the last scenario which incorporates modified running air-condition scheme to mitigate smoke was the best scenario.

Experimental and Theoretical Analysis of the Smoke Layer Height in the Engine Room under the Forced Air Condition

“…If the smoke is used as the control body, as shown in Figure 12, the control body always obeys the mass conservation equation during the smoke settling process. There are three main aspects in the process of quality change in the control body: (1) The smoke generated at the fire source enters the control body to increase the quality of the smoke in the control body; (2) the fresh gas provided by the mechanical air supply enters the smoke layer; (3) the upper mechanical exhaust port removes part of the smoke. The main energy transfer process in the cabin can be assumed to be that the heat generated by the fire source in the cabin is divided into three parts: a part of the heat is used to heat the gas in the cabin; a part of the heat is dissipated outward through the wall; a part of the heat is dissipated outward through the smoke outlet.…”

“…In recent years, the problem of smoke control in ship fires has attracted much attention [1][2][3][4]. The smoke control of the engine room mainly relies on the mechanical smoke exhaust system and the mechanical air supply system.…”