Study On The Deposition Of Particulate Matter In The Urban Rail Vehicle Air Conditioning Duct

With the acceleration of urbanization process and the increasing of the population in China, urban rail vehicles have become the major means of transport in people’s daily travel. As an important factor to affect the comfort and health of passengers, the air quality in the car is becoming more and more important. Particulate matter deposition in the air conditioning duct system will affect the in-car air quality and even endanger the health of passengers seriously. Therefore it is of great significance to study the deposition regularity of particulate matter within urban rail vehicle’s air conditioning duct.This article is based on urban rail vehicle air conditioning delivery conduit to study the deposition regularity of particles in the air duct, and the main research contents are as follows:(1) The physical and chemical properties, mechanical properties, dynamic characteristics and the influencing factors of the particle deposition in the air duct are theoretical analyzed.(2) In the experimental study, the regularity of particle deposition accretion and the deposition velocity in the main air duct of the static pressure air duct are studied. The influence of different particle deposition surface, the air velocity and the surface roughness on the particle’ deposition sedimentation are analyzed.(3) On the basis of experiment, the method of numerical simulation(renormalization group k-ε two equation model and discrete phase model) is used The discrete phase model is optimized, such as the boundary conditions, then numerical simulation model’s reliability and validity are verified by means of comparing with the experimental data.(4) The particle deposition accretion in the static pressure cavity were simulated using discrete phase model. The deposition accretion and the deposition velocity of different particles whose diameter is 1 μm、2.5 μm、10 μm and 30 μm are compared and analyzed. In this way, the influence of particle size on the deposition regularity is studied.Through the study on the particle deposition regularity of the urban rail vehicle’s air conditioning duct, the cleaning and maintenance proposals of particle in the duct are put forward, which can provide the basis for the design and routine cleaning and maintenance of air duct. In this way, we have an important significance in reducing the particle deposition in air duct, maintaining the inner surface cleaning of air duct and improving the air quality inside the carriage.