A Research on Operating Performance Verification and Energy-Efficient Heat-Rejection of the Variable-Refrigerant-Flow System

• Main Authors: Yu-Sheng Hung, 洪裕昇
• Other Authors: Kuei-Peng Lee
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/fh7f67

碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系碩士班 === 98 === Under the crisis of global warming and energy price rising, efforts to save energy become significant issues of engineering studies. Thus, U.S. Department of Energy and Efficiency Valuation Organization published the “International Performance Measurement and Verification Protocol (IPMVP)”. The IPMVP promotes four concepts of energy saving measurement and verification to evaluate performance of efficiency. This research focuses on analyzing the office buildings, to evaluate energy consumption features of the new-generation Variable-Refrigerant-Flow System through the dynamic building energy simulation program, EnergyPlus. This research aims to analyze and compare the condensing-unit’s performance curves between EnergyPlus default curves and real curves constructed by the performance raw data provided by the manufacture. And analyzed history data and set up an empirical model of condensing-unit, in order to establish a practical energy efficiency verification approach. The result of wisdom supervisory control apparatus and full-scale experiment comparing with actual baseline leads to the basis of energy auditing. The performance chart of condensing-unit has been established in order to provide the data basis of loss coefficient for duct design. High density of tall buildings always causes short circulation of airflow, resulting in insufficient heat rejection and the decrease of energy efficiency for the outdoor unit. This research focuses on analyzing the office buildings. And for the other main point of this research is processing full-scale air-flow analysis by computational fluid dynamics (CFD) software, and build the optimum air flow to reduce cooling energy. The numerical results reveal, that inappropriate installed position of arrayed outdoor units is easy to cause non-uniformity of heat-rejection flow and short circulation of airflow, resulting in the rise of average air-return temperature of the outdoor unit by 2.6~4.7 ℃. The wind field characteristics of buildings, and Cold/Hot Aisle can reduce average air-return temperature about 2.9 ℃, compared to those without sufficient openings. The results of this study can offer manufacturers to check appropriateness of their design and ensure the efficiency of equipments.