The Efficiency Analysis of Screw Compressor with Variable Vi in Heat Pump System.

• Main Authors: CAI, PENG-HONG, 蔡朋宏
• Other Authors: LEE, KUEI-PENG
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/gedgc7

碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系 === 107 === In vapor compression heat pump system, the compressor's energy consumption determines the overall energy consumption. If good compressor control technology can be developed, it will save a lot of energy costs. This study is based on experimental method and develops a heat pump system with variable Vi. It uses the variable Vi to control the compression ratio of the compressor, compressor variable frequency drive and expansion valve control to optimize the system operation. The experimental benchmark conditions were established by using the on-site design of the hottest water outlet temperature of 55℃, R134a refrigerant properties, various working conditions and screw compressor with variable Vi. The experimental results of linear correlation show that the average adiabatic compression efficiency of Vi2.4 is better than Vi3.0 about 5.08% and Vi3.5 about 10.56% when the system compression ratio is less than 3.5; COP_H is better than Vi3.0 about 2.98% and about 10.77% of Vi3.5 . When the system compression ratio is 4.5, the adiabatic compression efficiency of Vi3.5 is better than Vi2.4 about 7.09% and about 0.10% better than Vi3.0 is; COP_H is better than Vi2.4 about 11.38% and about 9.40% better than Vi3.0. At the hot water outlet temperature of 55 °C, the Vi3.5 compressor's energy consumption is less than Vi3.0 about 2.76% and less than Vi2.4 about 7.57%.