Natural Ventilation Of Marine Engine Room

The main purpose of ventilation in marine engine room is to set up and maintain a suitable circumstance (temperature, humidity, velocity, purity ) both for the engines and engineers. Natural ventilation, which uses the power of wind on voyage and the thermo pressure existing between engine room and environment, is an economical method.One of the most important things in ventilation is to provide appropriate quantity of air flow. This paper, by comparing the calculating methods now used in engine room ventilation design, emphasizes the necessary to consider the air both for burning and for heat exchanging during ventilation calculation, and then put forword the point that it is possible for marine engineers to use a main engine load associated table or curve provided by designers as a guide to manage the quantity of air flow.There are lots of factors that can affect the natural ventilation, such as the flow way and velocity of wind which can produce huge affection but is difficult to be considered by quantity. In this dissertation, the affection of the area of inlet and outlet windows, the height of inlet window, the diameter of inlet duct to the ventilation air quantity is to be researched, By lowing the height of inlet duct, the flow resistance will be reduced, but the extend of the reducing is not too high, so the inlet window can be put in a higher position in order to avoid the water coming from sea wave. It can be seen that the bigger the area of the inlet and outlet window, the more quantity of air flow, of course, this is being limited, if one of this window area is not big enough, and only enlarge another. Expanding the diameter of inlet duct, choosing better type and making a good arrangement will rising the flow quantity effectively.