The effect of using electric motors of the different energy classes by start-up process in screw compressors on efficiency and performance analysis

Compressors have become an important part for manufacturing factories with the increase of automation systems in industries. It is used in almost all kinds of manufacturing sectors, from textile to mining, from automotive to pharmaceutical industry. Therefore, due to its various advantages, today the number of factories that do not have compressors is very low. In compressed air systems, the main substance of the system is air. At the same time, compressors are the largest energy source used in industrial activities after electrical energy. For this reason, the efficiency of compressors will contribute to energy savings and competitiveness. In the industry, the most used compressor type is screw compressors. Screw compressors consist of two types, oily and oil free. Oily type compressors work according to the principle of increasing the pressure with the narrowing of the volume between two screws (female and male rotors) that drive each other. It is more difficult to control the resulting heat in oil-free compressors. The coupled model transfer method is the most modern transmission type used today. In these models, the screw block is directly connected to the electric motor. Today, there are also belt-pulley type screw compressors used for transmission. However, there will be losses in transmission due to friction. In terms of starting types, screw compressors are star-delta and frequency controlled (inverter) air compressors, which are called driver or variable speed in industry language. Soft starter is also used in some applications. In these applications, IE2, IE3 and IE4 energy class electric motors are used. In many factories, the purchase of compressors, which constitute a large part of the energy consumption, is carried out unplanned and unconsciously. With the increase in energy costs in our country, the issue of compressors started to be addressed in the first investments made by companies. In this process, interest in electric motors and inverter compressors with high energy efficiency has increased. In the literature on inverter compressors, how much air the business needs, the more electricity will be consumed to meet the air requirement. Screw compressor with inverter will automatically control power and speed without stopping and starting. Screw compressor with inverter will automatically control the operating power and speed thanks to the inverter without stopping and starting. Thus, it is suggested that the system will be kept at the desired pressure and will consume as much energy as the energy requirement and will provide a great advantage in energy costs. In this thesis study, it was aimed to create ideas about the effect of transfer modes and starting methods on energy efficiency in a specific system such as compressor and what should be done to increase efficiency in screw compressors In this thesis, it is aimed to create ideas about what should be done to increase efficiency in screw compressors by examining the effect of transmission and starting methods on energy efficiency in compressors. For this purpose, compressors of different power have been tested in the field and the measurements taken have been analyzed comparatively. In the light of air flow, package power measurement data and specific power calculations obtained from 75kW and 250kW screw compressor models, evaluations were made on the effects of starting methods, efficiency class of electric motors and transmission types on screw compressor efficiency. The factors causing the values obtained in the measurements made were interpreted. In addition, with the development of this thesis, suggestions were made regarding the literature and the industry.