Simulation on along-railway oxygen demand of the Qinghai-Tibet Railway passenger cars

Passenger cars running in the Golmud-Lhasa section of the Qinghai-Tibet Railway are taken as samples for improving the oxgen supply system of the cars. The Lumped Parameter Method is employed to establish a dynamic model of the changes of oxygen content inside the cars, and the Matlab's SimuLink is used to simulate the internal oxygen level of the cars. The oxygen content curves inside and outside the cars are acquired under respective circumstances i.e.: no oxygen supply and the supply being controlled to keep the oxygen pressure at 13.7 kPa. Moreover, the least real-time oxygen supply amount along the railway and the least final total amount are obtained. These results are compared with the results of practical engineering formulas based on a steady-state. Analyses show that a little modification to the practical engineering formulas would make the two results become very close. Consequently, it is simple and feasible to calculate the oxygen demand with the modified steady-state practical engineering formulas instead of the dynamic method.