Simulation Of Air-Distribution In Avitation Building With Large-Scale Space

With the rapid urbanization in China, the construction industry goes to unprecedented growth. Due to the acceleration of modern pace of life and rapid development of traffic, the airport terminal has also been growing so fast that the airport terminal will become the most energy consumption, where a variety of equipments and devices will be running for visitors gathering and a variety of activities held. Therefore, energy saving for the airport terminal is becoming more and more important. As a special large-scale building, the airport terminal has complex function and various systems, it is difficult to control the stability and comfortability of air distribution, such as air temperature, speed and humidity. Thus, it's very important to design a reasonable air distribution to reduce the cooling load and energy consumption in the airport terminal.In general, there are four types of air distribution systems to be used in large space, such as the stratified air conditioning, displacement ventilation, under-floor air distribution and impinging jet ventilation. The FLUENT software is used in this paper to simulate the air distribution in terminal 2 in Hongqiao airport. At first, stratified air conditioning systems is being simulated and the results states that some problems have been happened on the previously design of stratified air conditioning system, such as low temperature, large wind speed. The improved air distribution model has been put forward and been validated by numerical simulations in this paper, the results tell that the existing problems in the previous design can be resolved by decreasing the velocity of the supply air and by installing the exhaust outlet on the same side with the air supply outlet, but the exhaust outlet should be installed in the lower position. With this improved model the previous stratified air conditioning systems can be optimized and more effective.Besides, the other three type air distribution systems have been simulated for Hongqiao project to compare their airflow performance and energy consumption.(1) By comparing the effect of temperature stratification, it's clear that impinging jet ventilation shows most distinct, the other three types of air distributions makes little difference;(2)By comparing the wind speed in the working area, it is found that the wind speed in stratified air conditioning is higher than the recommended value, while the wind speed in the other types of air conditioning can meet the design requirements;(3) By comparing wind velocity uniformity, it can be known that impinging jet ventilation is the best, followed by the displacement ventilation and stratified air conditioning, while under-floor air distribution is the poorest;(4) The comparison of temperature uniformity tell that impinging jet ventilation is the best, followed by stratified air-conditioning and under-floor air distribution, while displacement ventilation is the poorest;(5) After the comparison of energy consumption, it is found that displacement ventilation is the smallest, followed by the impinging jet ventilation and under-floor air distribution, stratified air conditioning.With the study results in this paper, it is clear that impinging jet ventilation air supply mode is best suited to large space of the terminal building, followed by the replacement ventilation, under-floor air distribution, stratified air conditioning.The study of this paper can be valued for the optimized design of air conditioning system in terminal building space, and also can be used for the improvement of indoor thermal environment and energy-saving.