VENTILATION CONTROL TO REDUCE AIRBORNE CONTAMINANTS

研究结果表明，空气中的污染物水平 猪圈养通常有足够的水平来构成健康 对从事该职业的工人构成危险。除了一种微粒 成分可达到26毫克/立方米，气体存在于 大量的限制包括甲烷，硫化氢，氨， 和二氧化碳。养猪户公认的呼吸道疾病 包括上呼吸道炎症、哮喘样综合征和慢性 气流限制。与猪相关的通风系统 禁闭主要是为了提供舒适的环境 那些猪。然而，因为禁闭是以营利为目的的 在此基础上，与运行通风系统相关的成本为 通常通过将风扇使用量降至最低来保持最低水平，这会导致 保持较高的空气污染物水平。这项研究建议 涉及反馈控制理论的应用，以设计一个 将运行该系统的自动限制通风系统 以一种同时最小化竞争需求的方式 将成本和污染物水平降至最低。在设计之前和 测试了这种控制方法，分析了其时变性 两种污染物(总粉尘浓度和氨水平)和 两个气候因素(温度和湿度)将在 一年中被关在猪圈里的过程。这项工作将导致 确定使用的实时传感器的准确性所需的信息 来测量这四个“输出”变量，并指出 测量信号的噪声质量。连续测量 风扇速度改变期间的这种类型也将被用来确定， 和数学模型，变化之间的动态关系 输出变量和风扇转速的变化。从一个关于 输出变量的噪声质量和动态行为，设计 并对几种可能的反馈控制方法进行了仿真 使用专门为此目的开发的软件执行。一个 拟议研究的最后方面将涉及一系列测试 最好的候选控制方法采用全尺寸 通风测试设施。未来的工作将涉及到 某厂最优控制方法的开发与试验 设施；开发其他工程控制方法以 最大限度地减少空气中污染物的产生和迁移 限制；以及通过以下方式验证控制方法的实用性 测量空气中污染物水平和肺功能的变化 工人们。

Studies have shown conclusively that airborne contaminant levels in swine confinements are typically of a sufficient level to pose a health hazard to workers in that occupation. In addition to a particulate component that can reach levels of 26 mg/m3, gases present in confinements in high amounts include methane, hydrogen sulfide, ammonia, and carbon dioxide. Recognized respiratory diseases of swine farmers include upper airway inflammation, an asthma-like syndrome, and chronic airflow limitations. Ventilation systems associated with swine confinements are largely designed to provide a comfortable climate for the pigs. However, because confinements are operated on a for-profit basis, costs associated with operating the ventilation system are typically kept to a minimum by minimizing fan usage which results in maintaining high airborne contaminant levels. This research proposal involves the application of feedback control theory to design an automated confinement ventilation system that will operate the system in such a way as to simultaneously minimize the competing needs to minimize both costs and contaminant levels. Prior to the design and testing of such a control method, an analysis of the time-varying nature of two contaminants (total dust concentration and ammonia levels) and two climate factors (temperature and humidity) will be performed over the course of year in a swine confinement. This work will result in information needed to ascertain the accuracy of real-time sensors used to measure these four "output" variables as well as to indicate the noise qualities of the measurement signal. Sequential measurements of this type during a change in fan speed will also be used to determine, and mathematically model, the dynamic relationship between a change in output variable and a change in fan speed. From a knowledge of the noise qualities and dynamic behavior of the output variables, the design and simulation of several possible feedback control methods will be performed using software specifically developed for this purpose. A final aspect of the proposed research will involve a series of tests of the best candidate control methods with the use of a full-scale ventilation-testing facility. Future work would then involve the development and testing of the best control method in an actual facility; the development of other engineering control methods to minimize the production and migration of airborne contaminants in a confinement; and a verification of the control method's utility by measuring the change in contaminant levels and the lung function of workers.