Penalty Function Method for The Optimum Control of Air-Conditioning System

• Main Authors: Kai-Tai Wong, 黃啟泰
• Other Authors: 陳希立
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/70834823841715572101

碩士 === 國立臺灣大學 === 機械工程學研究所 === 94 === This dissertation applied Penalty Function Method (PFM) to determine the optimal control of multiple centrifugal chillers. In multiple chiller system, chillers have different performance during the actual operation. According to each chiller performance, PFM is used to determine the optimal chiller load distribution to minimize the input power and satisfy the cooling demand. The applying of PFM controls the on-line chillers to operate at high efficiency and turn off the inefficient chillers to reduce the energy consumption. The optimal chiller load distribution by using PFM are compared with the equal load distribution (ELD) and Lagrange multiplier method (LGM) to show the feature of this method. The results show that the PFM can save 9.57% total power compared with ELD and also have 4.05% power save compared with LGM at high system cooling load. At the low system cooling load, PFM saved 63.83% total power consumption of multiple centrifugal chiller system. In addition, a total solution of multiple chiller system control can be considered the influence of cooling tower. The power consumption of a chiller is sensitive to the condensing water temperature, which affected by the cooling tower air flow rates. This study using the optimal chiller load distribution by using PFM and the speed control of cooling tower fan, to optimize the condenser water temperature and tower air flow and reduced the power consumption of chillers and towers. The results shows the application of variable speed driven cooling tower can save about 2% total power compared with constant speed driven tower.