Branch-and-Bound Method for Optimal Chiller Sequencing

• Main Authors: Fu-Ann Lin, 林福安
• Other Authors: Yung-Chung Chang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/04136310230611513429

碩士 === 國立臺北科技大學 === 冷凍與低溫科技研究所 === 91 === Taiwan is located in the subtropical zone, and the weather is torpid and humid in summer, which causes large-scale demand for air-conditioning. This is the main reason for the rapid growth of power usage during peak hours in summer. Air-conditioning takes up much of the power usage. Taiwan is short of natural energy resource, with 97% of the energy resource imported from other countries. In addition, the range of electricity usage between peak and lay hours is widening, which causes increasing cost of power supply. To lower the cost of power supply, improve the application frequency of equipment, and minimize the possibility of power shortage and limitation, it is essential to employ power demand management and effective control over power usage. “Chiller unit” accounts for most of the energy consumption, with an estimate of over 60%. Focusing analysis on the cost of “Chiller unit”, as the expectant usage is set for functioning in 20 years, most of the cost is derived from the electricity bill, with an estimate of 82%. This indicates that the overall functioning efficiency of air-conditioning system is closely related to the efficiency of Chiller unit. In light of this, this thesis is aimed at applying Branch and Bound to Optimal Chiller Sequencing. It is based on the current available Chiller unit and predicted usage rate of the day before that decision about when to start up Chiller unit into chilled water system chain functioning is made. Accordingly, the highest efficiency rate is sought to provide optimal system combination for the power usage of air-conditioning. That is, optimal combination is sought out for each Chiller unit, and every Chiller unit of air-conditioning system is ensured to be undergoing the best efficiency rate to decrease power usage and achieve the end of optimizing the system.