湿式除尘中液滴对气溶胶粒子捕集效率的影响

发布时间：2018-03-10 16:01

本文选题：气溶胶　切入点：颗粒物浓度　出处：《东华大学》2013年硕士论文　论文类型：学位论文

【摘要】：随着我国社会经济发展加快和社会地位的提高,人们对居住环境的要求进一步提高,已不再局限于传统的温度、湿度和速度的要求,而是对室内外空气品质提出了更高的要求。同时随着国家出台对污染物浓度控制的限值,如何去除污染物成为研究热点。因此,本文采用数值模拟的方法对液滴从空气中去除气溶胶颗粒物的机制和过程进行分析讨论。模拟采用先前文献关于典型单个液滴捕集气溶胶颗粒物的数据,分别运用气--固两相流的层流和湍流模型。对于单液滴捕集气溶胶进行了数值计算。在相同的实验条件下将模拟结果和经典实验数据进行对比,结果表明,本文的数值计算模型是可靠一致的。在数值模式得以验证的基础上,针对层流状态下的不同粒径颗粒物进行了模拟。对测液滴直径,速度和粒径对颗粒物轨迹、浓度和沉积状态的影响、颗粒物分布以及被捕集的规律进行分析总结。结果表明：随着液滴直径增大,对同一直径的粒子捕集效率逐渐降低；在液滴直径相同时,随着粒子直径的增大,捕集效率则是逐渐增大。此外,模拟针对湍流状态下的颗粒物轨迹,浓度和沉积状态进行了研究。结果表明,湍流的因素对颗粒物捕集效率存在明显影响。液滴直径、速度和粒径等因素对颗粒物捕集效率的影响不同。通过一系列的模拟对比,可知,湍流状态下的捕集效率明显大于层流状态下的捕集效率。液滴对大粒子和小粒子在层流和湍流下捕集效率的差值随着液滴直径变化趋势不同。
[Abstract]:With the acceleration of social and economic development and the improvement of social status in China, people's demand for living environment has been further raised, and is no longer limited to the traditional requirements of temperature, humidity and speed. At the same time, with the introduction of limits on the concentration of pollutants, how to remove pollutants has become a research hotspot. In this paper, the mechanism and process of removing aerosol particles from air by the method of numerical simulation are analyzed and discussed. Using data from previous literature on the capture of aerosol particles by typical individual droplets, The laminar and turbulent models of gas-solid two-phase flow are used to numerically calculate the single droplet trapping aerosol. Under the same experimental conditions, the simulation results are compared with the classical experimental data, and the results show that, The numerical model in this paper is reliable and consistent. Based on the verification of the numerical model, the effects of droplet diameter, velocity and particle size on the trajectory, concentration and deposition state of particles in laminar flow were simulated. The results show that with the increase of droplet diameter, the trapping efficiency of particles of the same diameter decreases gradually, and when the droplet diameter is the same, the particle size increases with the increase of droplet diameter. The capture efficiency increases gradually. In addition, the trajectory, concentration and deposition of particles in turbulent state are studied. The results show that the turbulent factors have a significant effect on the capture efficiency of particulate matter. The effects of velocity and particle size on the capture efficiency of particulate matter are different. The trapping efficiency in turbulent state is obviously higher than that in laminar flow, and the difference between droplet trapping efficiency for large particle and small particle in laminar flow and turbulent flow is different with the change trend of droplet diameter.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU834.637

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