Paper Title
COMPARISON AND ANALYSIS OF ENERGY-SAVING PERFORMANCE OF AIR COMPRESSORS

Abstract
Abstract - As electricity costs account for 70-80% of the lifecycle costs of air compressors, the industry's primary strategy is to implement variable frequency drives or improve control methods to save energy. Although adopting innovative methods has been effective, it often overlooks the specific requirements for the compressor system under individual needs. Pursuing further energy efficiency sometimes leaves users unsure of how to choose the appropriate air compressor system that suits their needs without going to extremes. This study takes a 5hp reciprocating air compressor and a 5hp permanent magnet screw air compressor as examples. Under the same industrial demand, both types of compressors are controlled by a variable frequency drive to achieve energy efficiency. The energy consumption is monitored through a human-machine interface system. Next, the energy consumption of the two types of air compressors under the same demand is compared. Experimental results show that measuring the current while starting the operation from 0kg/cm2 to a stable pressure of 7kg/cm2, it is observed that the screw compressor outperforms the reciprocating compressor in terms of pressurization speed and time to reach stable pressure. Moreover, the total power consumption of the screw compressor is approximately 25.1% lower than that of the reciprocating compressor. Finally, the electricity cost difference between the two types of compressors is calculated, with the screw compressor saving 4.116 TWD per hour in electricity costs compared to the reciprocating compressor. In addition, when the discharge pressure of the air compressor is set to 7kg/cm2, with a fixed discharge flow rate of 0.3m3/min, the average power consumption of the reciprocating compressor and screw compressor are 3.39 kW and 3.1 kW, respectively.Through analysis of power consumption, specific power, and electricity cost, it is found that during long-term operation, the energy consumption of the screw air compressor is significantly better than that of the reciprocating air compressor. This study can provide a reference for the industry or other users in constructing or updating air compressor equipment in the future. Keywords - Air Compressor, Energy-Saving.