Numerical Simulation Of Air-conditioning And Ventilation System In Intensive Care Unit

Based on the outbreak of SARS at the end of 2002, how to accommodate and cure the corresponding patients more safely and promptly has been taken into great consideration in the construction and reconstruction of most hospitals in China. The air-conditioning and ventilation system plays a crucial role during the process. However, no specific handbook for the air-conditioning and ventilation system concerning the practical construction of Intensive Care Unit has been released. At present, the construction of Intensive Care Units is at the stage of mutual imitation and tentative improvement. As to the academic research of the system, only one or two factors which influence the in door air quality have been studied in many cases. In fact, there is lack of systematic research for a complete system. Therefore, probing into the most reasonable air-conditioning and ventilation system for the Intensive Care Units is of great realistic significance.It was very difficult to determine the air distribution which is affected by lots of factors. In recent years, with the rapid development and application of the computing technology, the power of numerical simulation has been becoming much stronger, which makes the air distribution simulation with hydrodynamics available. This thesis established and solved physical and mathematical models based on various air supply and return pattern, diffuser number, diffuser types, air change per hour and ceiling height by using CFD software.In order to determine a better indoor air distribution and corresponding design parameters, to guide the air distribution design and to meet the needs of the comfort and cleanness level, this thesis studied the numerical simulation results of the temperature fields, the velocity fields and the concentration fields of Intensive Care Units which were equipped with different systems. The main conclusions are: based on the analysis of comfort level and cleanness, the up supply low return system is better than the side supply low return system; higher ACH will show better performance in contaminant elimination.The research method adopted in this thesis can also be used as reference for the design and evaluation of the air distribution and ventilation pattern in common buildings.