Research Of Airflow Pattern Optimization In A Negative Pressure Isolation Ward

Some diseases, like tuberculosis, pneumonia and influenza are all diffused by airwith respiration. SARS(Severe Acute Respiratory Syndrome)is one kind of suchairborne disease that is diffused through respiration and touch. From the late of 2002,it broke out in several provinces in China and over 30 countries. Furthermore, therewas a tendency of explosion in larger areas. Especially in the beginning of SARSexplosion, mounts of people who worked in hospital were infected. As a result, theinfection rate of these people in hospital is much higher than that of other people,which causes a lot of scientists to pay more attention to the health protection inhospital. Negative pressure isolation ward is one kind of protective facility that cankeep a negative pressure to prevent the microorganic contaminant particles to spreadout. At the same time, a proper indoor airflow pattern can effectively move thecontaminant particle to the outlet of the ward, and then filtered by the high efficiencyparticulate (HEPA) filter.This research bases on the former research of negative pressure isolation ward.At first, the character of SARS disease and the way it diffuses are analyzed when thevirus exists as microbe aerosol. Then it illustrates that it is an important way to controlthe aerosol by airflow. Secondly, the study uses the Computational Fluid Dynamics(CFD) knowledge to simulate the airflow in a real ward. Different with the formersimulation, it adopts the RNG k -ε turbulence model instead of the standard k -εturbulence model. This change is proved that the new turbulence model can give amore precise result than before by using comparsion. The results calculated by CFDare analyzed and get the optimal airflow pattern. Furthermore, the optimal air changerate is confirmed by analyzing several factors. Finally, this thesis shows the shortageof traditional way of airflow research and presents a new way to deal with airflowpattern, the way of proportional model testing cambined with Particle ImageVelocimetry, which is proved to be effective. All these results can be referred inbuilding of negative pressure isolation wards and establishing relative designguidelines.