Abstract Machining plants are often highly polluted indoor environments with dense oil mist generated from metalworking fluids. Workers exposed to oil mist may suffer serious health problems. General ventilation is often used to dilute the oil mist level below the threshold of health risk. However, it is not easy to organize the flow for ventilating a large machining plant with hundreds of machines in order to effectively remove the oil mist. In order to develop an effective ventilation system, this study validated a computational fluid dynamics (CFD) program with the RNG k-e model at a high Grashof number by using the measured air temperature and contaminant concentration in several locations in a high-ceiling lab with heat and pollutant sources. Next, the validated CFD program was used to develop an improved displacement ventilation system in which air is supplied from the lower parts of the support columns in the plant. With thermal plumes generated by machines and workers, the system formed unidirectional airflow that carried pollutants away from the work area of the factory. The system reduced the oil-mist concentration by more than 70% compared with existing ventilation system. In addition, suspended radiant heaters are recommended for supplemental heating in winter.

中文翻译：

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一种改进的机械加工厂置换通风系统

摘要 加工工厂通常是高度污染的室内环境，金属加工液会产生浓密的油雾。接触油雾的工人可能会遭受严重的健康问题。一般通风通常用于将油雾水平稀释到健康风险阈值以下。然而，要想有效地去除油雾，在拥有数百台机器的大型加工工厂中组织通风并不是一件容易的事。为了开发有效的通风系统，本研究通过使用高天花板实验室中多个位置的测量空气温度和污染物浓度，验证了具有高 Grashof 数的 RNG ke 模型的计算流体动力学 (CFD) 程序。和污染源。下一个，经验证的 CFD 程序用于开发改进的置换通风系统，其中空气从工厂支撑柱的下部供应。通过机器和工人产生的热羽流，该系统形成单向气流，将污染物从工厂的工作区域带走。与现有通风系统相比，该系统将油雾浓度降低了 70% 以上。此外，建议在冬季使用悬挂式辐射加热器进行补充供暖。与现有通风系统相比，该系统将油雾浓度降低了 70% 以上。此外，建议在冬季使用悬挂式辐射加热器进行补充供暖。与现有通风系统相比，该系统将油雾浓度降低了 70% 以上。此外，建议在冬季使用悬挂式辐射加热器进行补充供暖。