CFD model Evaluation of Smoke Control, Fire and Gas Detection Systems in Clean Rooms of High-Tech Plants

• Main Authors: Chen, Yu-Jen, 陳佑任
• Other Authors: Shu, Chi-Min
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/hye59g

博士 === 國立雲林科技大學 === 工程科技研究所 === 107 === Technology development has driven the development of various technology industries, increasing the need for 3C chips. To produce large quantities of chips, suppliers have been expanding their production lines at a quick pace; and to increase the yield of products, the demand of clean rooms has become more stringent. Cleanliness requirements for related processes made it difficult for field testing in clean rooms, therefore this research based design specifications on the majority of clean rooms to build the test model. This research assess some problem in fire control, detection, and gas leakage detection in clean room by CFD model. The evaluation models were setting by actual condition in clean room. Fab smoke exhaust system is approved as a better system to exhaust smoke, because hot gas will entrain air to go up with flow stream to the smoke exhaust system. 4500 CMM was found having the best exhaust efficiency for 2MW and 5 MW fires. The loss area is smaller for stopping or derating FFU in the fire zone than no smoke curtains scenario in this research. Because of alarm thresholds, smoke detectors in the Fab did not actuate in early stages of clean room fire. Therefore, the Air Sampling-Type Smoke Detector, (ASD) systems were required below the raised floor and the dry-coil for monitoring. Evaluation of airflow and diffusion within clean rooms showed light and heavy gases are both affected by the downward airflow of the FFU, resulting in a higher diffusion rate below elevated floors than above them. In addition, high levels of ventilation can dilute the leaked gas, resulting in an unobvious TWA leakage area for gas leaks below 0.1 g/s. Toxicity detectors should be installed within 1 g/s leakage areas below raised floor to ensure effectiveness, and be closer to actual conditions within clean rooms. Clean rooms are highly ventilated areas, and are difficult to perform tests and assessments. For evaluations regarding smoke control, fire detection, and gas leaks, this research can act as basis for protection of current factories, as well as aid in the design of new facilities. CFD models can be utilized to predict the interior airflow and other related parameters needed for protection. These results can be quantified and is important data for future facility improvements or designs.