Numerical Simulation Study Of Air Distribution Of The Air-Conditioning System For Heifei Railway Passenger Station

With the rapid development of high-speed railway in China, many of the cities will built large railway passenger stations as a key project of the municipal planning. As a typical large space buiding, railway station has a large volume of space, the ratio of window area and wall area is high, personnel and light is intensive. To ensure that the thermal environment of the station waiting room meeting the human thermal comfort requirements, but also as far as possible to reduce the energy consumption of air-conditioning system, reasonable airflow is essential.Hefei railway passenger station with stratified air-conditioning, which was the research target of this paper. According to the size of the actual structure of the station and the air-conditioning design parameters, eatablished three-dimensional CFD computational models with the stratified air-conditioning design of the station. Computational fluid dynamics software STAR-CD was used to simulate the station waiting room interior flow field in summer and winter, analyzing detailed airflow situations of different air supply angle in summer and winter.For summer conditions, without changing the other parameters of the supply air, analysed detailed temperature and velocity distribution of the waiting room under three air supply angle,0degree,15degree,30degree. Using Air Diffusion Performance Index(ADPI) to evaluate the quality of airflow organization under three conditions. The research found that the temperature and velocity in the passenger active regions of15degree angle was more reasonable. Therefore,15degree angle was recommended to use as the summer air supply angle in the practical engineering.For winter conditions, taking into account the buoyancy influenced by the thermal jet,-10degree,-20degree,-30degree three angles were selected as the study conditions. The distribution characteristics of temperature and velocity in the elevated waiting hall staff activities zone under three conditions were got.Using performance evaluation index of airflow, indoor environment of three cases was analyzed qualitatively. By contrast, the stratified air-conditioning’s heating effect was best when supplying warm air under-30degree angle. Therefore,-30degree angle was recommended to use as the winter air supply angle in the practical engineering.Finally, pointing at the deficiencies of the stratified air-conditioning heating’s design scheme, some suggestions for the optimization were provided. By adjusting the air flow distribution and supply air temperature, the original air supply scheme was improved. Improvement program compared with the original program, the results showed that the uniformity of airflow distribution in waiting area under the improved program was better. And the ADPI value increased to twice of the original one. Improvement effect was obvious.After the research, this dissertation obtains some results, which can guide the air-conditiong design of Hefei railway passenger station and offer the reference for similar large railway stations.