Numerical Simulation And Optimization Of Air Flow In Atrium Of Commercial Building In Xi’an

With the development of economy and the transformation of the life style of human being, the time that people lives indoor is becoming longer and longer. When the architecture being designed, how to maintain good indoor environment causes more and more concern. In recent years, the structure of the architecture has greatly changed gradually with the development of building material and design philosophy. More buildings with huge space are got used or being constructed continuously, of which the atrium is one kind of the huge space. The atrium embodies the philosophy to be closed with and return to the nature, which could develop a great ecological function that agrees with the domestic philosophy, that is harmonious and natural. The airflow in an atrium has great influence on the thermal comfort and energy consumption, which is the main research point recent years. In this paper, the research of the ventilation pattern, including mixed ventilation and displacement ventilation(DV), of an certain market atrium has been conducted by numerical simulation. The CFD method has been used to study the influence of the airflow pattern, air-supply angle and boundary condition on the atrium indoor thermal comfort, of which the efficiency and reliability have been verified by experiment results.In this paper, the main work are as follows:1. In the summer, the temperature in the occupied zone is well-distributed, and an obvious stratification is formed upper the occupied zone under the mixed ventilation. Under the DV, the temperature stratification would formed in the whole space. Both the mixed ventilation and DV would form obvious vertical temperature difference. Compared with each other, we have the conclusions as follows:(1) the temperature near the ceiling of the DV is higher than that of the mixed ventilation, under the condition that the exhaust fan should run to save energy, then the DV is more energy-saved;(2) the DV would rise thermal plume near the thermal source, while the mixed ventilation wouldn’t;(3) The airflow in the occupies zone are more uniform and the temperature is lower in the DV than that of in the mixed ventilation. Compared with the PMV and PPD, the DV thermal comfort is better than that of the mixed ventilation;(4) When the atrium needs heat supply in the winter, the temperature in the whole space is more uniform and no obvious temperature stratification.2. The jet angle has great influence on the velocity and temperature field and thermal comfort. Compared with different jet angles, the thermal comfort is better than those of other angles when the atrium needs to be cooled in the summer, so the best jet angle is positive 7o.3. Considering that the positive pressure is not adequate, so the influence of infiltrate is studied. With the CFD simulation, there is no temperature stratification upper the occupied zone while opposite in the occupied zone.4. The temperatures on the designated points were agreed with the temperatures collected by experiment, which verifies the efficiency and reliability of the CFD method.