Research And Optimization Of Ventilation And Cooling System For Aircraft Electronic Equipment Cabin

The development and production of large aircraft in China represents the direction and strength of the country’s aviation industry.However,in order to achieve excellent aircraft design and high-quality production,advanced electronic equipment and its ventilation and cooling systems are essential.Therefore,in-depth research on the ventilation and cooling of electronic equipment compartments in large aircraft is of great significance to enhance the core competitiveness of China’s aviation industry and national comprehensive strength.This thesis focuses on the ventilation and cooling system of the electronic equipment compartment of a certain type of wide-body twin-aisle passenger aircraft.Based on the analysis of the thermal balance mechanism of the electronic equipment compartment,the thermal characteristics of the cabin structure were calculated using ANSA-Nastran software to obtain the thermal boundaries of the electronic equipment compartment.Additionally,the Realizable k-ε turbulence model was used to analyze the ventilation and cooling characteristics,and a direction for optimizing the thermal management was proposed.Furthermore,the thesis proposed the design concept of hierarchical cooling and designed a precise air supply structure for a closed equipment box equipment rack.Finally,the SHERPA algorithm was used to optimize multiple objectives of the ventilation system and obtain the optimal design solution.The main content and research results are as follows:(1)This thesis investigates the heat transfer mechanism of the wall structure in an electronic equipment cabin and establishes its thermal balance equation.ANSA-Nastran software is used to analyze the temperature changes of the structure under twelve different operating conditions in summer and winter,resulting in temperature distribution cloud maps under different conditions.The extreme value method is then employed to extract the cabin wall structure temperature during the taxiing phase in summer,which serves as the boundary for the wall temperature field in the regional temperature field.(2)The study analyzed the ventilation and cooling system of an electronic equipment cabin through fluid dynamic simulation.An enclosed equipment rack with precise air supply structure was proposed for improved cooling based on graded cooling concept.Optimization parameters for both the enclosed equipment box and equipment rack in the ventilation system were explored to improve system performance.Results showed that the optimal design parameters for the enclosed equipment box were a wall distance of 7.50 mm and a pipe diameter of 21.80 mm,while the optimal design parameter for the enclosed equipment rack air flow plate angle was 7.62 °.(3)This study optimized the cooling scheme of an electronic equipment cabin using the graded cooling concept and the "Promoting efficiency without raising energy consumption" idea.The optimized scheme was compared with the original ventilation system,and results showed a decrease in maximum temperature on the surface of the electronic equipment by about 170 ℃ and an average temperature of about 77 ℃ after implementing the optimized scheme.These findings demonstrate the efficient performance of the enclosed personalized ventilation and cooling system.