Numerical Simulation Of Indoor Contaminant Distribution Of Building For Vehicles Preparation In A Transportation Hub

The construction of comprehensive transportation hub not only improves thetransportation capacity of the urban traffic, but also provides the public with conve-nient, safe and reliable travel conditions. However, the enormous traffic volume andpedestrian volume generates a lot of contaminants. Automobile exhaust and CO₂fromhuman respiratory are the main indoor contaminants. There are tens of kinds of au-tomobile exhaust, including a variety of gases which are harmful to human body.Andif the indoor CO₂concentration is too high, it will lead to lots of symptoms in humanbody, such as shortness of breath, a terrible headache and high blood pressure. Bystudying the distribution characteristics of indoor contaminants, this thesis puts for-ward the optimization design of the architectural form and ventilation air conditioningsystem, so that some consult ideas for improving the indoor environment of thetransportation hub can be provided.In this thesis, the building for vehicles preparation of a certain comprehensivetransportation hub in Changsha is taken as an example, the velocity field, temperaturefield, contaminant concentrations field and age of air in long-haul departure area,short-haul departure area as well as waiting room are simulated by using numericalsimulation methods, then the rationality of the design of ventilation and air condi-tioning system can be evaluated, the irrational points can be optimized and verifiedthrough simulation.As the architectural form has a significant impact on the distribution of indoorcontaminant, the optimizations of the architectural forms of long-distance departurearea is proposed in the thesis, adopting simulation analysis of seven different exterioropen models.By comparing the distribution of indoor contaminant concentration un-der different wind velocities, it is obvious to find that the velocity of air supply has animportant effect on the indoor contaminant concentration. The higher the velocity ofsupply air is, the higher the efficiency of indoor contaminants discharge will be.Aiming at the problems that CO concentration of local area and the indoor averagewind velocity are both too high in the short-haul departure area, and CO concentrationis nonuniform as well as the temperature is too high in local area of the waiting room,optimization schemes are proposed in this thesis. Simulation results show that theindoor CO concentration is reduced by10%on average in the short-haul departure area, the average wind velocity is cut down by5%, while the indoor CO₂concentra-tion is reduced by6.7%on average, at the same time, the temperature of the trape-zoidal area decreases obviously with a drop of2-3℃in the waiting room.