Research And Implementation Of Performance Optimization Method For Passenger Oxygen System On Plateau Route

After the cabin decompression of a civil airliner occurs,it needs to descend altitude urgently,use the oxygen supplement device on the aircraft to supplement oxygen for passengers.The current oxygen supplement regulations stipulate the oxygen partial pressure of passengers at different altitudes,but no specific supplementary oxygen is given.the regulation of tracheal oxygen partial pressure as an oxygenation indicator is not applicable to passengers with lung diseases.When the aircraft executes the high altitude route,due to the high safety altitude of the route and the complicated and changeable terrain,the aircraft cannot directly descend the altitude.It is necessary to formulate emergency descent procedures according to the oxygen system restrictions and the route topography,the overall weighing is relatively cumbersome.Moreover,during the descent process,the oxygen flow rate needs to be continuously changed as the altitude of the aircraft changes,which places higher requirements on the control accuracy of the oxygen regulator.Firstly,according to CCAR 25.1443(c),the calculation models of minimum oxygen supply flow and oxygen quality for passengers at different heights are established,and the calculation results of the models are analyzed;Then,combined with the shortcomings of the current regulations,the paper analyzes the calculation methods and the relationship among the three physiological indexes: tracheal oxygen partial pressure,alveolar oxygen partial pressure and blood oxygen saturation;Then,according to the calculation model of oxygen supply flow and the principle of engineering fluid mechanics,the calculation model of oxygen supply flow and oxygen regulator valve opening is established.Combined with the model,the PI fuzzy control method for oxygen regulator valve is designed and simulated;Finally,the performance software for calculating the minimum safe altitude of the route and making the emergency descent program of the aircraft cabin is written by using C # programming software.The calculation results show that the passenger minimum oxygen flow calculation model and the oxygen quality calculation model can provide reference for the oxygen supply in the event of cabin pressure loss.In view of the deficiency of CCAR 25.1443(c)in the minimum oxygen supply flow for passengers based on the partial pressure of oxygen in trachea,this paper puts forward a modification proposal based on the minimum oxygen saturation,so that it can better reflect the actual oxygen supply level of passengers with different physiological conditions compared with the partial pressure of oxygen in trachea,the new regulation is not limited by the aircraft oxygen system in practical application.Through the simulation of the designed PI fuzzy control method,the error between the actual oxygen supply flow and the theoretical oxygen supply flow is less than 0.1%,which has practical application value.The cabin pressure loss safety analysis software is used to analyze the pressure loss oxygen supply of a319-115 aircraft on Chengdu Urumqi route.The results show that the cabin pressure loss emergency descent program calculated by the software meets the oxygen supply requirements and can be applied to the actual oxygen supply analysis.