Abstract:

The regulation of temperature, pressure, humidity and oxygen intensity of an aircraft cabin is crucial for the flight conditions of a commercial aircraft. Lack of oxygen, lower temperature and pressure induce some health problems for passengers on board. For this reason, hot and pressurized air supplied from aircraft engine compressor section is conditioned in the air-conditioning packages to present comfortable ambience inside of the aircraft cabin as well as cooling of electric components. In this study, an air-conditioning system of Airbus A330 as a commercial aircraft has been investigated at the altitude of 11000 m for 289 people on board under the flight conditions. At this altitude for the aircraft cruising with 871 km/h (Ma = 0.82), cooling loads of cockpit (crew station), passenger cabin and other appliances needed cooling in the aircraft have been calculated. The parameters affecting the cooling load are mainly temperature, pressure and air intensity of aircraft inside and atmospheric outside. In the calculation of the cooling loads, generated heat and heat loss have been considered. For the generated heat value, heat generation by passengers, cabin crew, illumination systems, other equipment and solar radiation have been assumedly calculated. The heat loss from the aircraft fuselage at 20 °C cabin to the outside of the aircraft at -56.5 °C has been found. Heat transfer to meet the fresh air need inside the aircraft has been taken into account. Finally, the obtained cooling loads are 7.4 kW for the maximum value and 5.1 kW for the minimum value at these aforementioned conditions. The maximum and minimum values have been obtained for the daytime and the night time depending on solar radiation, respectively. In the upcoming study, energy analysis is going to be combined with the exergy analysis and the appropriate air-conditioning system for the optimum energy consumption will be evaluated.

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