Improving the Ventilation of Machinery Spaces with Direct Adiabatic Cooling System

Abstract

Machinery spaces are provided with ventilation systems that ensure the necessary airflow for combustion and cooling. In some vessels, due to space constraints, the requested air flow for cooling cannot be achieved under extreme environmental conditions, and the engine load will need to be reduced. On the other hand, the outside air temperature can increase over 35 °C in some places, and the efficiency of the ventilation will be reduced. In these cases, other solutions for cooling the engine room should be analyzed. In this paper, the environmental conditions in the Romanian Danube area are analyzed to understand whether direct adiabatic cooling can be used to improve ventilation systems and what the challenges are after increasing the relative humidity inside the machinery spaces. Based on the data recorded, it was found that outside relative humidity substantially drops when the temperature increases, which ensures good conditions for the use of adiabatic cooling. This study demonstrates that by using direct adiabatic cooling, the air flow of the ventilation system can be reduced by more than 50%, which will reduce the pressure drop across the ventilation system, together with noise and energy consumption. After adiabatic cooling, the temperature and relative humidity inside the engine room will be fine for the functionality of the equipment, but the temperature–humidity index will be high, which means high discomfort for the crew. Therefore, it is concluded that this cooling solution should only be used in unattended machinery spaces.