THE INCREASE OF ENERGETIC EFFICIENCY OF SCREW COMPRESSORS USED FOR THE PRODUCTION OF COMPRESSED AIR INSIDE A COAL MINE.

The use of pneumatic energy in industry as well as in the tertiary system is quite frequent representing 10% of the industrial electricity consumption in the European Union, the life span of compressors being relatively long, namely between 14 and 16 years depending on the installed power. Although the compressed air demand of a coal mine is covered by performant compressors manufactured by well-known producers there still are multiple possibilities to increase their energetic efficiency. The working method is constituted by the creation of hourly real and optimum exergy flow diagrams for the compressors being used. The paper brings forward numeric methods which use experimentally determined values as input data. Whereas the energetic efficiency of pneumatic systems is reduced the study highlights the possibilities to increase it considering the implementation of technical solutions which allow the achievement of 5 - 50% energetic economies. The present study also highlights that the technical measures destined to improve the energetic efficiency are feasible and economically efficient, the first steps being the implementation of measures which allow for the consumption to be measured and the cost of compressed air to be assessed, followed by the development of the structures which manage the consumption of energy as well as the investments. [ABSTRACT FROM AUTHOR]