工业车间高浓度大比重气态污染物迁移动力学机理及通风控制计算方法研究

Different from the indoor environment of civil buildings, many industrial workshops have a high concentration of heavier-than-air gaseous pollutants (gaseous pollutants with a relative density greater than 1) in the production process, such as Argon (Relative density is 1.4.) used as inert gas in mechanical industry, Uran hexafluoride vapor (Relative density is 12.1.) used as circulating fuel adjuvant in nuclear industry etc.. This kind of heavier-than-air gaseous pollutants seriously threaten the safety of industrial production. The dynamic mechanism of migration indoor of heavier-than-air gaseous pollutants is not clear due to the density effect. Especially, under the condition of complex source characteristics and physical boundaries, The uncertainty of the buoyancy direction in industrial workshops makes the design calculation of the air distribution essential. Therefore, for the density effect of heavier-than-air gaseous pollutants, how do we based on the identification of the migration and transport mechanism of heavier-than-air gaseous pollutants in typical industrial workshops, propose corresponding ventilation control design calculation method? It is an important issue that needs to be solved urgently. With theoretical analysis, CFD calculations, experiments and field measurements, it is aimed to (1) find out the migration and transport mechanism of heavier-than-air gaseous pollutants in typical industrial workshops; (2) obtain critical conditions for buoyancy direction change of heavier-than-air gaseous pollutants; (3) summarize the calculation method of ventilation control design. The project will promote the study of air pollution control problems in industrial workshops, and provide theoretical basis and calculation methods for related designs.

区别于与民用建筑室内环境，许多工业车间内生产过程发散着高浓度的大比重气态污染物（相对密度大于1的气态污染物），如机械工业惰性气体氩气（相对密度1.4）、核工业循环燃料辅助剂六氟化铀蒸气（相对密度12.1）等，严重威胁着人员安全健康。这类气态污染物密度效应导致了其在室内迁移的动力学机理不清楚，特别是工业车间复杂的源特性和边界条件下，浮力方向的不确定性，使通风气流组织设计计算至关重要。因此，如何在查明典型工业车间大比重气态污染物迁移输运机理的基础上，提出相应的通风控制设计计算方法，是亟待解决的重要问题。. 课题拟通过理论分析、CFD计算、试验和现场实测研究：.（1）探明大比重气态污染物在室内迁移动力学机理；.（2）获得大比重气态污染物浮力方向变化临界条件；.（3）总结归纳通风控制设计计算方法。. 课题将为工业车间大比重气态污染物通风控制设计提供理论依据。

区别于民用建筑室内环境，许多工业车间内生产过程发散着高浓度的大量污染气体和蒸气。工业生产过程中涉及到的大比重气体污染物，量大面广种类繁多，且密度范围大，相对密度范围可达1.4（氩气）~12.1（六氟化铀）。这些大比重污染气体将对长期作业人员健康和工艺设备安全运行造成积年累月的严重侵害。.通过三年的研究工作，完成了既定研究计划内容，包括大比重气态污染物在室内迁移的动力学机理；非等温条件下大比重气态污染物浮力方向变化规律；为室内存在大比重气态污染物的厂房等通风控制计算方法提供设计依据和参考。研究结果表明，在污染排除中，若热源强度越大，风口面积一定，所需的送风速度越大（温度通风效率骤增点所对应的Re和Ra近似成递增线性关系）；送风速度增大到一定程度时，污染物排除效率增加逐步放缓（污染物通风效率骤增点对应的Re和Ra成指数函数型关系）。室内空间温度分布和污染物分布主要受到污染源和热源表面的涡大小的影响，室内的污染物分布并非总是随着机械通风强度的升高而降低，还需要考虑与热源的相对位置关系及通风气流组织。