【作者】 杨可；

【导师】 朱能；

【作者基本信息】 天津大学 ， 供热、供燃气、通风与空调工程， 2004， 硕士

【摘要】 肺结核、流行感冒、肺炎等疾病主要是通过人们的呼吸作用,由空气进行传播的,其中包括非典型性肺炎(Severe Acute Respiratory Syndrome,SARS)。SARS是一种很典型的通过飞沫或近距离接触传染的呼吸道疾病。在SARS爆发的整个过程当中,尤其是在初期,医务人员的感染率明显高于普通人群。因此,人们开始关注在医院病房内SARS的预防和控制。负压隔离病房是利用病房内的负压(相对于外界)阻止病房内含有致病微生物的空气向外界扩散,同时,利用室内合理有效的气流组织形式,迅速地将病人呼出的含菌气体送入排风口,并经高效过滤后排出室内,以此达到安全防护的目的。本文首先介绍了目前世界上关于负压隔离病房的相关研究,指出了在气流组织方面存在的问题。然后,分析了SARS病毒在负压隔离病房内的传播及其特性,指出病毒是以微生物气溶胶形式存在,并通过室内的气流流动进行传播的。因此,室内合理的气流组织形式可以有效的控制病毒污染物的扩散。本课题利用目前广泛应用的数值模拟计算技术(Computational Fluid Dynamics,CFD),对病房内的气流流场和存在污染源的浓度场,进行了模拟计算。并且同以往普遍采用的标准k -ε湍流模型不同的是,本文采用了目前国外流行的RNG k -ε湍流模型,并通过实例计算和理论计算的对比,证明了其在计算房间内气流(低Re数流动)中的优势。并根据计算结果分析了不同气流组织形式,包括风口位置、尺寸、个数等,对室内流场和污染物浓度场的影响,确定了最佳的形式。而且根据多方面影响因素确定了最佳室内换气次数,为国内负压隔离病房的建设和规范的制定提供了参考。而针对传统的气流组织测试方法存在的一些不足,本课题采用了一种新的测试方法,即模型实验配合粒子图像速度场仪(Particle Image Velocimetry,PIV)的方法,通过实验说明了其应用的可行性。更多还原

【Abstract】 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.更多还原