利用逆方法預測潔淨室內汙染源之研究

Prediction of indoor pollutant source with the probability-based inverse method

陳祈帆(Chi-Fan Chen)

指導教授 ： 胡石政

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2012年)

摘要

一般潔淨室中對於汙染源的預測大多採取由已知點釋放汙染物(實驗或計算)，再觀察汙染源擴散的情況的方式來瞭解汙染物在潔淨室中的行為。在真實運轉中的潔淨室，通常我們只能觀測到結果，而無法得悉汙染物由何處而來，若擬求解此類工程問題一般採取「逆方法」運算求解。本研究採用「以機率法為基礎」的計算流體力學逆方法運用於估算一座三維潔淨室內的汙染源，並比對原先採取正向計算的結果。
結果顯示汙染物的擴散主要賴以潔淨室氣流的走向，當將氣流場反轉時，根據氣流循環汙染物向上擴散時容易在集中單側循環；透過加權機率模式來計算，其最高機率的位置確實與預設汙染源之位置一致。當增加偵測點數量時，偵測點數量較少的機率容易產生計算誤差，而偵測點數量較多時，其機率趨於穩定。針對釋放方式的改變，可以知道其結果並不會影響到預測汙染源之位置，但由於偵測點讀值的關係，其疊合之最高機率較為降低。

關鍵字

逆方法 ； 潔淨室 ； 汙染源偵測

並列摘要

The studies of pollutant dispersions and their spreading behaviors in a cleanroom, experimentally or numerically, are generally investigated based on the artificial emission sources. Detections of spreading pollutants in an operating cleanroom can be easily achieved using the respective indoor air quality monitoring systems but vice versa for the source identification. The identification of pollutant source is possible with the use of inverse numerical method. This study proposes a probability-based inverse method coupling with computational fluid dynamics (CFD) method, aiming to predict the pollutant source in an operating cleanroom with unilateral recirculation airflow field and compares the results with those obtained using the simulation model with an artificial source.

The diffusion of pollutants from an artificial source is mainly relies on the airflow fields in the cleanroom. For the proposed probability-based inverse method, with the airflow field in the reversed direction, the CFD results showed the aggregation of pollutants in the unilateral airflow field. By assessing the proposed probability weighting model, the location with the highest probability is found consistent with the default location of the artificial pollution sources. The results also showed that the increase of sensor detection points helps minimizing the calculation errors in the assessment of the proposed probability weighting function, and vice versa. Besides that, the varying methods of pollutant emitted has no significant effect on the identification of pollutant source but the calculation results based on the proposed probability weighting function are relatively lower.

並列關鍵字

Inverse methods ； clean room ； sources of pollution detection

參考文獻

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