【作者】 王迎辉；

【导师】 沈恒根；

【作者基本信息】 东华大学 ， 供热、供燃气、通风及空调工程， 2007， 硕士

【摘要】 随着工业和城市建设的快速发展，我国的大气污染严重，环境空气中微粒排放总量呈上升趋势，大多为微细的油烟和碳黑颗粒，这些颗粒会随空调系统的新风或经车间维护结构的缝隙随空气直接进入车间，使细纱车间空气受到污染，给产品质量带来影响。纺织厂“煤灰纱”的形成主要就是这些微细颗粒造成的，给纺织企业带来很大的经济损失。“煤灰纱”的形成受多种因素的影响，在纺织空调通风系统上主要有三个方面的原因。一是由于细纱车间的通风设计不能使车间保持微正压而使环境空气中微细颗粒随空气通过维护结构的缝隙进入车间；二是细纱车间空调系统的新风处理不能对环境空气中的微细颗粒进行有效净化；三是气流组织不合理造成局部涡流区而使车间内颗粒悬浮聚集而不能被循环风带走。本课题在明确环境空气中颗粒物的尺度与浓度分布特征、各种过滤材料的过滤机理和过滤性能的基础上，采取理论分析、数值模拟与实验相结合的方法，从系统角度探索解决细纱车间“煤灰纱”的防治问题。防治纺织企业“煤灰纱”的主要技术措施是对大气中的微细颗粒物进行有效净化，提高细纱车间空调系统的新风质量。本课题对不同克重的丙纶针刺驻极体过滤材料对微细颗粒物的过滤性能进行了实验测试，在不同的过滤风速下，对其过滤效率、过滤阻力和容尘能力等进行了分析和对比，从中优选出高效低阻的驻极体过滤材料用于防治“煤灰纱”。并分析了驻极体过滤材料在雨水淋洗及自来水浸泡后过滤性能的变化，根据滤料容尘量进行寿命的估算，对驻极体滤料的选择与使用周期等提出建议。采用通风的方法保证细纱车间的微正压，并采取合理的气流组织减少涡流是防治纺织企业“煤灰纱”的主要技术措施。纺织厂细纱车间的通风状况比较复杂，车间空气的压力分布受到有组织的机械进、排风和无组织新风渗透的影响。本课题对细纱车间的通风状况进行了分析和研究，在考虑热压、风压影响下的新风渗透的情况下，通过建立细纱车间颗粒物浓度模型，分析了机械送、排风对细纱车间压力分布的影响，并考虑送、排风温度差异，采取质量平衡的计算方法，得出车间正压通风计算公式。在此基础上，提出了保证细纱车间微正压的技术措施，实现用有组织的进风与排风来控制无组织的进风。利用Fluent软件对细纱车间的不同通风方式的气流组织情况进行模拟，通过分析车间整体气流流场分布情况、车弄及设备上方的温、湿度分布情况，并进行气流组织评价，认为上送下回二侧送风与置换通风方式气流组织均匀，较适合细纱车间使用。更多还原

【Abstract】 With the rapid development of industry and city construction, the air pollution in our country becomes serious. The quantity of the minute particles in the air increases rapidly, the majority of which are soot and black carbon particles. These particles can enter the spinning department with the fresh air of the air conditioning system or the penetrating air through the gaps of the maintenance structures, and are absorbed to the surface of the bobbin yarn. When their coverage areas attains to a certain degree, the foggy occurs, which will make a negative affect on the quality of the yarn, and bring huge economic losses to the textile company.There are many reasons for the foggy yarn, three of which occurs from the ventilating and air conditioning system. Firstly, the workshop can’t maintain the micro-positive pressure against the atmospheric pressure, thermal pressure and wind pressure, thus the soot and black carbon particles enter directly. Secondly, the air conditioning system can’t purify the fresh air sent to the workshop effectively. Thirdly, the airflow distribution is unconscionable. Considering the features of the particles in the air, the filtration fabrics’ purifying mechanism and performance, this paper tries to bring forward some effective measures to eliminate the foggy yarn in the cotton mill, on the research of theoretical analysis, numerical simulation and experiments.The filtration fabric can be used to purify the fresh air of the air conditioning system and control the foggy yarn. The paper makes experimental researches to compare and analysis the purifying efficient, resistance and dust capacity of different density Polypropylene Electret Materials at various rates, and the result shows that the filtration fabric with higher purifying efficiency and lower resistance. Besides, the purifying performance of the Electret Materials after drown in the rain and tap water are studied and its longevity are also predicted with its dust capacity, thus advices for choosing appropriate Electret Materials were given in the paper.This study concluded that the most effective methods to eliminate the foggy yarn were to maintain the micro-positive pressure by ventilating and reduce the vortex with appropriate organized air supply. As the air distribution is complicated in the spinning department, through considering the penetrating air under the thermal pressure and wind pressure, the analysis showed that the pressure distribution was affected by the organized air supply and exhaust and unorgnized penetrating air by establishing a concentration model of the particles. Besides, the paper made the formulation based on mass consistent to keep its micro-pressure under the conditions of temperature difference between the supply and exhaust air. The analysis on the FLUENT simulation of airflow distribution under different ventilation style in the spinning department showed that up-supply and down-exhaust intake with three-supply-inlet style and displacement ventilation are the most effective air styles.更多还原