An Experimental Study on Water Hammer Effects in Process Cooling Water System of a TFT-LCD Manufacturing Plant

• Main Authors: Wen-Ping Hsueh, 薛文評
• Other Authors: 蔡尤溪
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/yquf8w

碩士 === 國立臺北科技大學 === 冷凍空調工程系所 === 94 === There are many methods to avoid the damage of piping systems from water hammer. Often water hammer arresters are installed, but water hammer arresters need to be replaced periodically and the cost is significant. This study proposes to use the concept orifice bypass to lessen the effects of water hammer. An experimental test model of a typical TFT-LCD process cooling piping system was setup and an orifice plate was installed at upstream side of the control valve where water hammer effects are most likely to occur. The water pressure waves due to the abrupt closure of the control valve were studied. The relationship between the water flow speed and the water waves was studied and the most suitable diameter of orifice plate was discussed. It was found that the orifice has helped to reduce water hammer wave peak value and the duration of wave excitation. It was found that orifice diameter of more than 3 mm can reduce the water hammer effects significantly. This study also experimented with the combination of orifice and relief valve to prevent damage from water hammer effects. The results of study can help to reduce the operating cost besides reducing the risk of damage from water hammer effects.